Vaccines – pneumococcal and influenza

Dr Louise Johnson educates us on winter vaccines pneumococcal and influenza – for people living with diabetes.

What is pneumococcal disease?

Pneumococcal disease is caused by the bacterium Streptococcus pneumonia (S. pneumonia). This can cause infection in the respiratory tract i.e. lung, sinus or ears.

In vulnerable people, such as children, the elderly, and people living with diabetes, these bacteria can invade the bloodstream and cause meningitis and septicaemia. This may lead to deafness, mental disability and even death. People at extreme ages (younger than two years or older than 65 years) are particularly susceptible to the complications because of their underdeveloped immune system or aging immune system.

Pneumococcal bacteria are spread from person to person through close contact with respiratory secretions (sputum or saliva).

Why immunise?

It is estimated that immunisation approximately prevents 2,5 million deaths a year due to infections. It is also cost-effective to the health system and has saved more lives than the development of antibiotics.1

Antibiotic-resistance is a reality, and resistance to commonly used antibiotics is becoming a serious threat to medical treatment of infections.

In the age of antibiotic-resistant bugs, the prevention of disease through vaccines has become essential. It not only helps prevent infections in vaccinated people, but also prevents a “herd immunity” by helping to prevent transmission of the bug to close contacts of the sick patient.

Types of vaccines:

There are two different types of pneumococcal vaccines available:

  1. PPV23 (Pneumovax 23)

Pneumococcal polysaccharide vaccine is made from polysaccharide (sugar like) capsule of 23 different strains of S. pneumonia.

This capsule is the main target of the body’s immune response during pneumococcal infection. The body produces antibodies when exposed to the capsule (acts like an antigen).

The next time the immune system is exposed to the same antigen, the immune system is prepared and can rapidly produce killing-antibodies. This is due to the body having a “memory” of the antigen via specially produced immune memory B-cells.

Children younger than two years of age have an immature immune system and cannot produce memory cells to the capsule. Therefore, they should not get this vaccine.

  1. PCV13 (Prevenar 13)

Pneumococcal conjugate vaccine is like PPSV23. Though, a protein that induces memory cells, even in young children, joins the capsular polysaccharide.

Who should be vaccinated with which vaccines?

Pneumovax 23:

Persons older than 65 years.

People older than two years with chronic heart and lung disorders, diabetes, chronic liver disease, COPD, alcoholism, spleen dysfunction, asplenia (spleen removed), cancer, organ transplantation, HIV infection and smokers.

Prevenar 13:

Children aged: six weeks, four months, and 12 months.

Children with underlying medical conditions should get an extra dose at six months. This is part of the South African Immunisation Programme.

How to vaccinate?

South African guidelines to CAP (community acquired pneumonia)2

Vaccination is the key pillar of antibiotic stewardship.

  • All patients older than 50 years who are vaccine naïve should receive a single-dose of PCV13.
  • Every adult older than 50 years who have received PPV23 should receive a single-dose of PCV13 one year later.
  • All adults older than 65 years of age who are vaccine naïve should receive a single-dose of PCV13, followed a year later by PPV23.
  • Every adult older than 65 years of age who have received PPV23, should receive a single-dose of PCV13 at least one year later.
  • Younger adults (>18 year) who are vaccine naïve with severe underlying comorbid or immunocompromising conditions, including HIV infection, should receive a single-dose of PCV13, followed at least two months later by PPV23.
  • Younger adults (> 18 years) who have previously received PPV23 and have severe underlying comorbid or immunocompromising conditions, including HIV infection should receive a single-dose of PCV13 one year later.
  • All women who are pregnant in the period of influenza vaccine availability, should be offered vaccination with influenza vaccination of that year.
  • Adults older than 65 years of age should receive the annual vaccination for influenza.
  • Individuals with chronic diseases (diabetes, lung disease, heart disease, HIV infected individuals and morbidly obese (BMI>40kg/m2) are at high risk and should be vaccinated.
  • All healthcare workers should be offered annual influenza vaccination.

Who should not be vaccinated?

Pneumovax 23 should not be given to children younger than two years. Hypersensitivity to the products in the vaccine.

What are the side effects of the pneumococcal vaccine?

Side effects are very uncommon. Local side effects to the injected area: redness, soreness, or rash. Also fatigue, headache, chills and diffuse achiness.

What is influenza?

Influenza (also known as flu) kills between 6 000 and 11 000 South Africans per year. These deaths are 50% in the elderly and 30% in HIV infected people.

The highest rate of hospitalisation is in people older than 65 years of age, HIV-infected people, and children less than five years of age.

Patients with chronic diseases, such as diabetes, heart and lung disease and tuberculosis are also at higher risk of contracting influenza.3

Flu is a virus and is spread from person to person. It causes many different symptoms from headache, fatigue, muscle pain, shivers, vomiting and diarrhoea.

It spreads mainly by droplets when people cough, sneeze, or talk. You can also get flu by touching a surface or object that has flu virus on it and then touching your mouth, eyes or nose.

What is in the flu vaccine?

The flu vaccine contains three different types of inactivated flu viruses. This mean the virus is dead and can’t make you sick. The viruses in the flu injection are named for the year they were found and the place they were found. This year’s vaccine (2019) was updated with two new viruses. The current vaccine contains:

  1. A/California/7/2009(H1N1) pdm09 like virus
  2. A/HongKong/4801/2014(H3N2) like virus
  3. B/Brisbane/60/2008 like virus

Who should get the flu vaccine?

  • Pregnant and post-partum women (anytime during pregnancy).
  • People who are infected with HIV.
  • Healthcare workers.
  • People with chronic diseases (diabetes, lung, heart, kidney, liver, etc.)
  • People older than 65 years of age.
  • Residents of old age homes, chronic care and rehabilitation centres.
  • Children older than six months.
  • Adults and children in close contact with high-risk individuals.
  • Anyone wishing to reduce the risk of getting flu or spreading flu to others.

Who should not get the vaccine?

Anyone who had a severe allergic reaction to the vaccine, such as drop in blood pressure and difficulty in breathing.

Can I get the flu vaccine when I am sick?

Yes. You are safe to get the vaccine with mild cold or flu-like symptoms even if you have a fever. Though, if you are very ill (need to be admitted to a hospital) you should rather wait.

How effective is the flu vaccine?

The flu vaccine prevents only influenza and no other viruses. It is 60% effective in healthy individuals. The elderly and children younger than two years may not respond as well due to weaker immune system.4

Therefore, when looking at the bigger picture of population and personal health: be wise and vaccinate.


  1. Plotkin SA, Mortimer E.A, Vaccines 2ndedition, Philadelphia:Wb Saunders, 1994
  2. J Thorac Dis 2017; 9 (6):1469-1502
  3. ( (
Dr Louise Loot


Dr Louise Loot is a specialist physician passionate about diabetes and endocrinology. She enjoys helping people with diabetes live a full life with optimal quality. She is based in Pretoria in private practice.

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Understanding the Somogyi effect and dawn phenomenon

Diabetes nurse educator, Christine Manga, explains the causes behind elevated fasting blood glucose readings in the morning: Somogyi effect and dawn phenomenon.

Both the Somogyi effect and dawn phenomenon will lead to elevated fasting blood glucose (glucose level after an overnight fast) readings in the morning. The target for fasting blood glucose levels is <= 7mmol/L. This said, the causes are very different.

Dawn phenomenon

The dawn phenomenon occurs in everyone. However, people without diabetes will not notice it because their body is able to counteract the effects. It is caused by natural body changes during sleep.

During the night, less insulin is produced and in the early hours of the morning, hormones, such as cortisol, growth hormone, epinephrine and glucagon, are all released. These hormones all act in the opposite way to insulin, resulting in elevated blood glucose levels.

Towards the early hours of the morning, the body releases stored glucose from the liver into the bloodstream to provide energy for the coming day. This will cause a further rise in blood glucose levels. According to the American Diabetes Association, the dawn phenomenon occurs between 5:00am – 8:00am. The dawn phenomenon is a natural phenomenon.

Somogyi effect

The Somogyi effect is usually management related and is a rebound hyperglycaemia (high blood glucose). It happens in response to a nocturnal hypoglycaemia (low blood glucose).

This hypoglycaemia can be caused by giving too much insulin at night, not having an evening snack, or from doing vigorous exercise in the evening hours. In response to the hypo, the body releases hormones to raise the blood glucose levels. These include cortisol, growth hormone, glucagon and adrenaline. When you wake, you will have elevated fasting blood glucose level.

So, which one do you have: Somogyi effect and dawn phenomenon?

Due to the causes being different, the management will also differ. To establish what is causing your elevated fasting reading, you will need to do some extra blood glucose testing.

Testing your blood glucose levels between 2:00am – 3:00am on a few consecutive nights will give you an answer. If you are experiencing hypos at this time of night, then you are experiencing the Somogyi effect.

If on the other hand, your blood glucose levels are normal at this time, then you are experiencing the dawn phenomenon.

The use of continuous glucose monitoring (CGM) would be extremely useful in detecting the cause of your elevated blood glucose readings. CGM is now becoming more affordable, but definitely is still not cheap. Speak to your doctor about wearing a sensor to assist you in making management decisions.


Dawn phenomenon

To prevent the dawn phenomenon, you could:

  • Increase the amount of vigorous physical exercise in the evening hours.
  • Wear an insulin pump to administer extra insulin in the early morning hours. This would work well.
  • Reduce the amount of carbs and evening snacks.
  • Change insulin formulations to more concentrated ones. This can lead to improved fasting blood glucose levels.
  • Administer insulin later at night. This may also be beneficial.
  • There may be a need to change some of your diabetes medications, or possibly even add more.

Somogyi effect

Here are ways to prevent the Somogyi effect from occurring:

  • Reduce the amount of insulin given in the evening.
  • Once again, changing your insulin to a stronger concentration can prevent nocturnal hypos.
  • Giving the insulin earlier may also prove helpful.
  • Getting assistance with carb counting will help you to match the amount of insulin to the amount of carbs you eat, preventing overdosing of insulin.
  • Your doctor may need to assess your medication and reduce, or discontinue some.
  • Try to reduce the amount of vigorous physical activity in the evening.
  • It may also be necessary to have an evening snack before bedtime. The down side to this is that it may cause long-term weight gain.

The most important thing is that you know which one, the dawn phenomenon or the Somogyi effect, is causing your elevated fasting readings. You can only manage what you know.

eating time budget


Christine Manga (Post Grad Dip Diabetes and Msc Diabetes) is a professional nurse and a diabetes nurse educator. She has worked with Dr Angela Murphy at CDE Centre, Sunward Park since 2012.

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Depression and diabetes

Daniel Sher explores how diabetes and depression are linked, and gives some pointers for managing diabetes and depression together.

If you have diabetes, your chance of developing depression is two to three times higher than that of other people. As if we didn’t have enough to worry about already.

Why is this a problem?

Depression can make it harder for you to manage your glucose levels, often leading to diabetes burnout. Before you know it, you’re stuck in a vicious cycle of sadness, mood swings and poor blood glucose control.

What is depression?

Depression usually involves feelings of sadness, but depression and sadness are not the same thing. Rather, depression is a psychological disorder that affects a person not just emotionally, but also in terms of their thoughts and bodily functions.

Some of the symptoms of clinical depression include:

  • Ongoing sadness that doesn’t seem to ease up.
  • An inability to enjoy activities that previously brought you happiness.
  • Sleep disturbances.
  • Mood swings at home or at work are interfering with your relationships.
  • Concentration difficulties.
  • Suicidal thoughts and behaviours.
  • Inappropriate guilt and poor self-esteem.
  • Social withdrawal.
  • Changes in weight and appetite.
  • Low energy.
  • Less motivation to test your blood glucose, exercise and take insulin (diabetes burnout).

How common is depression in people with diabetes?

Time and time again, research studies have shown that having diabetes puts one at risk of developing depression. For example, a 2012 study showed that people with Type 1 diabetes are three times more likely to have depression; while people with Type 2 diabetes are twice as likely to be depressed.

Another 2019 study confirmed these numbers, leading the authors to say that reducing diabetes by 25% could stop 2,34 million cases of depression from happening. But, believe it or not, research shows that the relationship goes both ways. Having depression can also make a person more likely to develop (Type 2) diabetes.

Clearly, then, a close link between the two conditions exists. But why does this link exist? Why do depression and diabetes occur together so often?

Explaining the link between diabetes and depression

Injections. Finger pricks. Doctor’s visits. Lows. Highs. Dietary restrictions. Worry and fear. Yes, as people living with diabetes, we deal with a whole lot of stress. Is it really that surprising that we’re more likely to end up with depression?

Of course, living with diabetes comes with a psychological burden which in and of itself can trigger depression. But, the stress of diabetes alone doesn’t completely account for this link. This is where things get interesting.

Diabetes, depression and the brain

Recent research suggests that high blood glucose levels have a direct impact on the parts of the brain that affect mood and thinking. The researchers used a (fMRI) brain scanner to compare the brains of people living with diabetes versus people without the illness. The people living with diabetes were given some glucose to raise their sugars.

The scanners showed that when blood glucose levels went up, a certain brain chemical (glutamate) was released in parts of the brain that control thinking and emotions. Glutamate is closely linked to depression. The researchers also showed that people with worse glucose control over time had patterns of electrical activity in the brain that are linked to depression.

So, in other words, this study tells us that the link between diabetes and depression is not just a matter of increased life-stress: the two disorders are linked on a biological level. People living with diabetes experience changes in the brain that make depression more likely; and this is especially the case when blood glucose levels are high.

A vicious cycle

Many clients who approach me for help are stuck in a vicious cycle. They struggle to control their diabetes as well as they would like; and they soon start to develop signs of depression. The depression makes it harder for them to stay motivated and hopeful. They start to slack-off in terms of self-monitoring, diet and exercise. Their glucose control suffers as a result. This leads them to become even more depressed.

Why is this important?

For starters, if you are one of millions of people living with diabetes who is struggling with depression, know this: it’s not all in your head. The stress and strains of living with diabetes are very real. But, the illness also predisposes you to depression because of altered brain chemistry.

Now that we know this, it’s absolutely vital for doctors, patients and family members of people living with diabetes to know how to recognise the signs of diabetes and get help where needed. Treating both diabetes and depression together is vital.

How to get help

The good news is that this cycle can be broken. In most people, depression responds well to treatment. Let’s look at the two most common treatment options:

  1. Psychotherapy

Also known as talk therapy, counselling or just therapy. Speaking with a licensed mental health professional can help you to change the thoughts and behaviours that make depression more likely.

Cognitive behavioural therapy (CBT) is one of the most popular forms of therapy for treating depression. If possible, try to find a therapist who is experienced in working with people living with diabetes. It can really help to speak with someone who understands the struggles and nuances of living with a chronic illness.

  1. Medication

One of the most common forms of antidepressant medications is called a selective serotonin reuptake inhibitor (SSRI). Examples include Celexa, Lexapro, Zoloft and Zytomil. A 2006 research paper suggests that medication and therapy are equally effective in managing depression; and that the best outcomes usually occur when the two are combined.

  1. Lifestyle interventions

Therapists often include ‘behavioural modification’ to their treatment. This means empowering the client to make healthier choices when it comes to their diet, diabetes management and exercise patterns. Making positive choices in this regard can help you manage your depression and diabetes at the same time.

How to get help

If you are concerned that you may be developing depression on top of your diabetes, speak to your endocrinologist or general practitioner. Alternatively, you may want to make direct contact with a clinical psychologist or psychiatrist in your area. If possible, try to consult with a mental health professional who has experience in working with diabetes.

If you or a family member are suicidal, contact the South African Depression and Anxiety Group on their 24-hour suicide hotline: 0800 567 567.

Final thought

So, we now know that people living with diabetes are more likely to experience depression. Not just because their lives are a whole lot more stressful, but because diabetes, depression and the brain are all linked on a biological level. For those of us with diabetes, this means that we need to remain vigilant for signs of depression.

By getting the mental health treatment that you deserve, it’s possible to improve your overall quality of life and your blood-sugar control at the same time.


Bădescu, S. V., Tătaru, C., Kobylinska, L., Georgescu, E. L., Zahiu, D. M., Zăgrean, A. M., & Zăgrean, L. (2016). The association between Diabetes mellitus and Depression. Journal of medicine and life, 9(2), 120-125.

Chireh, B., Li, M., & D’Arcy, C. (2019). Diabetes increases the risk of depression: A systematic review, meta-analysis and estimates of population attributable fractions based on prospective studies. Preventive medicine reports, 100822.

Dimidjian, S., Hollon, S. D., Dobson, K. S., Schmaling, K. B., Kohlenberg, R. J., Addis, M. E., … & Atkins, D. C. (2006). Randomized trial of behavioural activation, cognitive therapy, and antidepressant medication in the acute treatment of adults with major depression. Journal of consulting and clinical psychology, 74(4), 658-670.

Endocrine Society. (2014, June 23). High blood sugar causes brain changes that raise depression risk. ScienceDaily. Retrieved June 19, 2019 from

Roy, T., & Lloyd, C. E. (2012). Epidemiology of depression and diabetes: a systematic review. Journal of affective disorders, 142, S8-S21.


Daniel Sher is a registered clinical psychologist who has lived with Type 1 diabetes for over 28 years. He practices from Life Vincent Pallotti Hospital in Cape Town where he works with Type 1 and Type 2 diabetes patients to help them thrive. Visit

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Tips for injecting insulin

Jessica Oosthuizen shares some useful pointers when injecting insulin.

Insulin therapy remains a fundamental and essential part of diabetes management. Many patients with Type 2 diabetes and all patients with Type 1 diabetes require insulin to keep blood glucose within target ranges.

However, this practice is still not performed optimally in many healthcare facilities, and insulin therapy is only effective if delivered into the correct tissue in the correct way.

The goal of exogenous insulin (insulin that is not made by the body but injected) is to reliably deliver the medication into the subcutaneous tissue, without causing any pain or discomfort and without any leakage of insulin.

The aim is to prevent injecting into the muscle. Injecting into the wrong space can affect the absorption and action of insulin. This can lead to unpredictable blood glucose control. To achieve this objective, it is important to select a needle that is the correct length.

What needles should be used for injecting insulin?

Studies have shown that shorter needles of 4mm are as safe and well-tolerated in comparison to longer ones.

Needles come with a different diameter and length. Those with a higher gauge number have a smaller needle diameter. Needles are available in 4-, 5-, 6- or 8-mm. Needles with a length of 12,7mm have an increased risk of intramuscular injection (which you want to avoid).

It is often assumed that a heavier person, with a higher BMI, may require a longer needle. However, we now know that 4-, 5- or 6-mm needles are suitable for all people with diabetes. Regardless of their BMI.

Insulin therapy should ideally be started using shorter length needles and these injections should be given at 90 degrees to the surface of the skin.

Children and teenagers

Children and adolescents should only be using needles with a length of 4-, 5- or 6mm. There is no clinical reason for using needles longer than 6mm. When injecting insulin into limbs, a skin-fold may be necessary, especially when using a 5- or 6mm needle.


In adults, including those with a high BMI in the overweight or obese category,  a needle that is 4mm, 5mm or 6mm in length should be used. There is no clinical reason to be using a needle >8mm. Patients who are using these needles should ideally change to a shorter needle. If this is not possible then lifting a skin-fold and/or injecting at a 45 degree angle should be adopted to avoid an intramuscular injection.

Injecting insulin into the muscle will cause: your body to absorb it too quickly; a more painful injection; and a shorter duration of insulin action time.

How many times can you use the same needle?

In a perfect world insulin needles would be used once and then safely discarded. Yet, realistically it’s common practice for needles to be reused. Especially, in a country, like South Africa, where resources are limited in both state and private sectors.

Although the risk of complications is relatively low in relation to the reuse of needles, some evidence does show that the reuse of needles can cause an increased risk of lipohypertrophy. This refers to swelling of the fatty tissue under the skin which causes fat lumps. It’s a relatively common side effect of insulin injections and can occur if multiple injections are given around the same area repeatedly.

Lipohypertrophy causes inconsistent and unpredictable insulin absorption, which can result in unexplained hypoglycaemia and glucose variability. It is for this reason that proper rotation of injection sites and regular changing of needles is essential.

Priming your pen

It’s important to remember that your insulin pen device should always be primed before the first dose and after every needle change.

Priming helps to remove any air bubbles that can collect during everyday use of your pen and ensures that you receive the full dose when administering insulin.

To prime your pen, dial up 2 units, hold your pen with the needle facing upwards and press down on the plunger. If you see drops of insulin come out at the top of the needle, then you know that your pen has been primed.

However, if you don’t see a flow of insulin then you must repeat the steps and continue until drops of insulin are visible at the top of the pen.

These same steps can be followed if you notice an air bubble in your pen. If an air bubble is present and you don’t remove it then you will not receive the correct dose of insulin.

You will notice this when you inject yourself. The air bubble causes a negative pressure when pointing the needle downwards into your skin and you will see a flow of insulin that is not injected and rather ‘spills’ out when removing the needle.

Final comment

Choosing the correct needles and ensuring removal of air when priming your insulin pen are two things that are easy enough to do. They can have positive effects on blood glucose control for people living with diabetes requiring multiple daily injections.


  1. FIT forum for injection technique in South Africa. Recommendations for best practice in injection technique. 1st 2014.
  2. Kreugel, G., Keers, J., Kerstens, M. and Wolffenbuttel, B. (2011). Randomized Trial on the Influence of the Length of Two Insulin Pen Needles on Glycaemic Control and Patient Preference in Obese Patients with Diabetes. Diabetes Technology & Therapeutics, 13(7), pp.737-741.
  3. Shah, R., Shah, V., Patel, M. and Maahs, D. (2016). Insulin delivery methods: Past, present and future. International Journal of Pharmaceutical Investigation, 6(1), p.1.
  4. Frid, A., Kreugel, G., Grassi, G., Halimi, S., Hicks, D., Hirsch, L., Smith, M., Wellhoener, R., Bode, B., Hirsch, I., Kalra, S., Ji, L. and Strauss, K. (2016). New Insulin Delivery Recommendations. Mayo Clinic Proceedings, 91(9), pp.1231-1255.
  5. Bahendeka, S., Kaushik, R., Swai, A., Otieno, F., Bajaj, S., Kalra, S., Bavuma, C. and Karigire, C. (2019). EADSG Guidelines: Insulin Storage and Optimisation of Injection Technique in Diabetes Management. Diabetes Therapy, 10(2), pp.341-366.


Jessica Oosthuizen is a registered dietitian and works in private practice at the Wits Donald Gordan Medical Centre. Being a Type 1 diabetic herself, since the age of 13, Jessica has a special interest in the nutritional management of children and adults with diabetes. She also has a key interest in weight management and eating disorders.

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Why glucose is the go-to

Jessica Oosthuizen explains why pure glucose is the preferred treatment for hypoglycaemia (low blood glucose).

“To fix a low blood glucose reading you need time, not more food.”

Hypoglycaemia remains a worry for many people living with diabetes and parents with children who have diabetes. It’s also one of the major limiting factors towards achieving good glycaemic control.

In diabetes management, when you are aiming for a blood glucose target of between 4 – 10mmol/L, it’s almost impossible to prevent hypoglycaemia all the time.

Hypoglycaemia can happen at any time of the day. Though, it may be more likely to occur before meal times, at the peak of insulin if the dose is incorrect, and during or after exercise.

Type 1 diabetes patients frequent hypoglycaemia the most. Followed by people with Type 2 diabetes managed by insulin and then people with Type 2 diabetes managed by sulfonylureas (antidiabetic drugs).

What is hypoglycaemia?

Hypoglycaemia means low blood glucose levels. It can be defined by:

  • A low blood glucose reading below 3,5 mmol/L. In children under six, this reading is below 4 mmol/L  because children may not be able to recognise symptoms or communicate with you.
  • Adrenergic and autonomic symptoms. These are symptoms caused by the body attempting to raise the blood glucose level. They include trembling, palpitations, sweating, dizziness, anxiety, hunger, nausea and tingling. These symptoms tend to start happening at a reading of between 2,8 and 4mmol/L.
  • Neuroglycopenic symptoms. These symptoms originate in the brain as a result of a deficiency of glucose in the central nervous system. These include difficulty concentrating, confusion, weakness, drowsiness, blurred vison, difficulty speaking, headache and dizziness. These symptoms are likely to occur at a reading below 2,8mmol/L.


Hypoglycaemia can be classified as mild, moderate or severe.

In mild hypoglycaemia, self-treatment is possible and blood glucose can easily be rectified to normal values.

With moderate hypoglycaemia, your body will react with warning signs, involving autonomic symptoms. You will be able to self-treat to bring blood glucose levels up.

When having a severe hypoglycaemic episode, you will require assistance from another person to give you something to eat or drink, or a glucagon injection.

In severe cases, you may lose consciousness and have seizures. Glucagon is a naturally occurring substance, produced by the pancreas, which supports the production of glucose to correct the hypoglycaemic state. This response may be slightly defective in Type 1 diabetes.

What causes hypoglycaemia?

Low blood glucose is caused by an imbalance between the factors that raise and decrease blood glucose levels. Those causing an increase in blood glucose include food and counter-regulatory hormones (glucagon, adrenaline and cortisol) and those causing a decrease include insulin or oral medication and physical activity.

With new technologies, such as flash glucose monitoring systems and continuous glucose monitors (CGMs), we get a clearer picture of what the blood glucose levels are doing over a 24-hour period.

This is compared to the traditional self-blood glucose monitoring (SBGM) system whereby with a prick of the finger you get your blood glucose reading of that given moment. In the case of SBGM, if you test your blood glucose and see that your levels are low, you have no idea where they may be going from there.

With CGMs and flash glucose monitoring systems, we can see in the form of an arrow which way the glucose is trending. And, with some of the newer CGMs, the rate at which it is trending up or down.

Common reasons for a low blood glucose reading:

  • Delayed or skipped meal.
  • Eating too little carbohydrates at a meal.
  • Overestimated the carbohydrates eaten, if using carb counting.
  • If you have exercised or been physically active.
  • Taken too much insulin in relation to what your body needs.
  • New injection site, therefore, avoiding lumpy tissue where insulin absorption is unpredictable.
  • Consuming alcohol.

How to treat hypoglycaemia?

This will depend on various factors, such as the rate at which the blood glucose is decreasing by, how much active or unused insulin is on-board, and when you last ate something carbohydrate-based.

Active insulin is the time that insulin remains working in your body, it refers to a bolus injection and this is usually 3-4 hours.

Having pure glucose is the preferred treatment for hypoglycaemia. However, any carbohydrates that contains glucose will raise blood glucose levels.

It is important to test blood glucose first, treat with the correct amount of rapid-acting carbohydrates, wait 15 minutes and then retest your blood glucose. If you are still not feeling better and your blood glucose has not risen, then you should repeat with the same amount of glucose. 0,3g of glucose/kg will increase the blood glucose reading by approximately 2 mmol/L.

Studies have shown that 15g of glucose is required to get an increase in blood glucose of approximately 2,1mmol/L within 20 minutes.

Examples of 15g of carbohydrate for the treatment of mild to moderate hypoglycaemia:

  • 15g of glucose in the form of glucose or dextrose tablets.
  • 15ml (3 teaspoons) of sugar.
  • 150ml of regular soft drinks.
  • 15ml (1 tablespoon) of honey.

Danger of over-treating hypoglycaemia

Over-treating hypoglycaemia should be avoided as much as possible because this can lead to rebound hyperglycaemia (high blood glucose) and weight gain.

To fix a low blood glucose reading you need time, not more food. It is important to note that the liver is also responsible for glucose output and rebound hyperglycaemia.

Glucose has a quicker effect on the blood glucose compared to other types of carbohydrates. You should avoid food and drinks containing fat, such as chocolates, biscuits or milk. The fat in these food items will delay digestion in the stomach and the glucose will therefore take longer to reach the bloodstream.

Fructose (the fruit sugar naturally found in fruits) is absorbed more slowly from the intestine and is not as effective as glucose in raising blood glucose levels.

Why can’t hypoglycaemia be treated with ‘real food’?

Treating hypoglycaemia with ‘real food’, for example, a banana will completely depend on the situation at hand. With the use of CGMs, we may be able to use ‘real food’ more frequently to treat a lower blood glucose reading before reaching the hypoglycaemic range.

With SBGM, we are limited because we only have that one reading for that specific time and no other information to tell us where we are going. Because of this, eating something like a banana (without any active insulin), may cause an undesirable rise in blood glucose.

Diabetes is an extremely unpredictable disease and it may be impossible to prevent all future hypoglycaemic episodes. It is important to evaluate your current diabetes management plan with your endocrinologist, diabetes nurse educator and registered dietitian to reduce and prevent large fluctuations in blood glucose readings.


  1. Wherret DK, Ho J, Hout C, et al. 2018 Clinical Practice Guidelines: Type 1 Diabetes in Children and Adolescents. Can J Diabetes 2018; 42: 234 – 246.
  2. Yale JF, Paty B, Senior PA. 2018 Clinical Practice Guidelines: Hypoglycemia. Can J Diabetes 2018; 42: 104 – 108.
  3. Barnard K, Thomas S, Royale P, Noyes K, Waugh N. Fear of Hypoglycemia in parents of young children with type 1 diabetes. BMC Pediatrics 2010, 10:50.
  4. Hanas, R., Type 1 Diabetes in children, adolescents and young adults. 6th Class Publishing: Bridgwater, 2015.


Jessica Oosthuizen is a registered dietitian and works in private practice at the Wits Donald Gordan Medical Centre. Being a Type 1 diabetic herself, since the age of 13, Jessica has a special interest in the nutritional management of children and adults with diabetes. She also has a key interest in weight management and eating disorders.

Diabetes: where science, art and education meet

Louise Johnson explains that the art of living skilfully with diabetes in the new millennium is possible with your own skill, science and the help of a team.

The Oxford Dictionary defines art as “the creation of beautiful or significant things” and “a superior skill that you can learn by study and practice and observation.”

In the new millennium, diabetes patients can acquire this art or superior skill by diabetes education. This can be in any form of information from your diabetes nurse educator, doctor, internet support group or books on the subject.

Insulin saves lives

Historically, diabetes mellitus was a deadly disease in people living with Type 1 diabetes. Prior to 1921, when insulin was first given to Leonard Thompson, people living with Type 1 diabetes died.

There has been a radical change and growth in information and technology since 1921. People living with Type 1 diabetes now have basal and bolus analogue insulin.

An analogue is an insulin that works as close as possible to normal human insulin. Recently two new basal second-generation insulin were launched in 2018: Toujeo (glargine U300) and Tresiba (degludec).

Both have a working time of more than 24 hours. This is truly a once daily long-acting insulin without any peaks or intra patient variability. In practise, this mean that the sugar values will stay the same if you eat the same food every day. Thus, it allows for suitable background insulin to build on.

The short-acting analogues currently available are all very effective. NovoRapid, Humalog and Apidra all have a working time of approximately four hours and start to peak after 30 minutes. There is a new shorter-acting analogue in the pipeline and will be available later this year in South Africa.

Science and art meet at carb counting

Most people living with diabetes complain, from time to time, that they want to eat something ‘naughty’, without all the consequences of high sugars and feeling terrible.

The answer (if you don’t know it yet) is carbohydrate counting aka carb counting. This method calculates the carbohydrates per meal and establishes the correct amount of insulin via an easy mathematical calculation. Carb counting should be practiced by all diabetes patients on rapid insulin.

This scientific method both establishes the correct amount of insulin per carbohydrate meal as well as the correct dosage to correct sugar to a glucose target. Your doctor will determine this target value. The before meal and two-hour after meal values are important for good sugar control.

This art of food/insulin calculations are only possible with blood glucose values. Previously, the only method was finger prick. The more pricks and sugar measures, the better the sugar control.

The past few years have brought about five glucose sensors that can now do this for you. No more or very little finger pricking needed. This is made possible by continuous glucose monitoring.

It is a sensor that measures interstitial fluid sugar values every five minutes. This data is sent via a transmitter regularly. This data can be seen on cell phone apps or a reader specifically for this purpose.

The CGM system has arrows on the screen that gives an indication of sugars going up, down or staying stable. The real positive of this device is the reduction of finger pricking, accompanied with better hands on evaluation throughout a 24-hour period of the trend of the glucose.

All this technology is great but it is imperative to follow the correct procedure.

Insulin injection – the basics:

  1. Keep insulin in a cold area/fridge.
  2. Make sure it has not expired.
  3. Secure an insulin needle on a pen every second or third day. If you still use syringes then ensure you replace every second or third day. Blunt needles cause damage to the injected area. This can later lead to lipodystrophy (fat cells that are unresponsive and not functioning anymore, very lumpy).
  4. Rotate insulin injections areas every time to prevent this.
  5. Do not inject on scars or tattoos.
  6. Insert the needle at 90 degrees into fat tissue and not muscle. Be careful of upper arms and thighs if you are very thin. Make sure to pinch fat tissue between thumb and finger and not muscle.
  7. After the insulin dosage is injected, keep the plunger in for 10 seconds to get the whole dosage delivered.
  8. Do not clean with alcohol since this can interact with insulin. Soap and water is more than enough.

Glucose testing – the basics:

  1. Make sure your hands are clean.
  2. Check the machine and strips, to be sure they are the same brand, and that the strips are not expired.
  3. Replace lancets frequently to prevent damage to fingertips.
  4. Do not test on other sites than fingertips.
  5. Always keep a spare machine or battery at hand.

Other artful skills to learn:

  1. Adopting a diabetic diet.
  2. Regular aerobic exercises, such as walking, swimming, or running.
  3. Yearly visit to the eye specialist for a retina examination.
  4. Yearly visit to the podiatrist to examine feet and help with removing of corns, calluses, and abnormal nails.
  5. Visit a specialist physician once a year for heart and kidney evaluation. This is important to ensure all your values are on target.

Targets to achieve:

  1. Normal weight with a waist circumference below 80cm for a woman and 98cm for a male.
  2. Blood pressure equal to or below 130/80 mmHg.
  3. HbA1c below 7% (people with heart and kidney problems can have a value up to 8% but your doctor will establish your correct value).
  4. Triglycerides less than 1,2 mmol/L.
  5. LDL (bad cholesterol) less than 1,8 mmol/L.
  6. HDL (good cholesterol) more than 1,0 for a male and 1,2 mmol/L for a female.
  7. Urine albumin: creatinine ratio less than 30 mg/min. 

Type 2 diabetes

The tablet arena has increased dramatically over the past five years. The basis to all Type 2 diabetes treatment protocols should still be metformin.

The options in cases where metformin is not sufficient depend on the patient’s risk factors for heart attack, weight problems and cost.

  • DPP4i (Galvus, Onglyza, Januvia)

These dipeptidyl peptidase-4 inhibitor (DPP4i) drugs work on the incretin in the gut of diabetics and cause food to stay in the stomach. This causes increased satiety. In addition, the liver and pancreas secrete less glucose. The pancreas secretes the correct amount of insulin. This group of drugs makes patients sensitive to their own insulin.

  • GLP-1RA (Victoza, Byetta)

This glucagon-like peptide-1 receptor agonists (GLP-1RA) class of drugs are injectable incretins. They work the same way as the DPP4i but cause a greater loss of weight.

  • SGLT2i (Forxiga, Jardiance)

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) is the newest class of drugs, especially for type 2 diabetes. They work in the top part of the kidney loop and prevent the reabsorption of sugar. This causes more sugar in the urine as well as lower blood sugar, lower blood pressure and 3 to 6kg weight loss.

In both Forxiga and Jardiance, there is sufficient data that showed improvement in mortality (risk to die) to both diabetics with previous heart attacks, strokes and heart failure and the group that only have the risk factors.

Dr Louise Loot


Dr Louise Johnson is a specialist physician passionate about diabetes and endocrinology. She enjoys helping people with diabetes live a full life with optimal quality. She is based in Pretoria in private practice.

Too much blood sugar, too bad for your ears

Audiologist, Sakhile Nkosi, unpacks whether there is a link between diabetes and hearing loss.

Every person living with diabetes worldwide knows upon diagnosis that there are different types of diabetes e.g. Type 1 and Type 2 diabetes. Your doctor likely provided rigorous counselling, explaining all the clinical manifestation present in diabetes, such as loss of sensation in the feet (neuropathy), vision disturbances, kidney problems, etc. and the importance of taking medication and maintaining a healthy lifestyle to prevent these complications.

Most research conducted, so far, gave concrete evidence on what can possibly go wrong with an individual living with diabetes. Though, one of the unfamiliar complications that the diabetic community isn’t often made aware of, is the effect of diabetes on the ear structure. Hence, hearing and balance.

The ear

The ear is one of the most important organs in the human body. It provides two basic functions: hearing and to balance. Hearing itself is a special sense, just like vision; it forms basis of communication.

Hearing loss occurs as a result of damage either in the outer, middle or inner (retro-cochlear) part of the ear. If hearing loss is left untreated, it can have negative consequences on an individual’s life. This includes physical, emotional and social health and can cause disturbing effects in relationships with colleagues, family and friends.  In children, hearing loss can cause a delay in speech and language development.

The link between diabetes and hearing loss and balance

Current research reveals the link between diabetes and hearing loss. As early as 2008, the National Health and Nutrition Examination Survey results found that individuals with diabetes are at risk of developing hearing loss compared to those without diabetes.

The results of the survey revealed that individuals with diabetes are prone to a degree of hearing loss ranging from mild to moderate. The type of hearing loss common in diabetic patients is sensorineural in nature, implying the hearing loss is caused by damage to the inner ear or the hearing nerve that carries sound to the brain.

In terms of balance, patients who are diagnosed with diabetes may be at a higher risk for falls. This happens because of how diabetes affects the normal function of vision, sensation in feet, ankles, knees, hips, and inner ears.

As you may be aware, diabetes can affect the normal function of the retina of the eye. If the retina is damaged by diabetes and vision is distorted, the brain is deprived of information and needs help to maintain your balance.

Diabetes also can affect whether you have sensation in your feet. If your feet are numb (due to diabetes), you’ll not be able to sense when you are leaning forward, backward or side to side. In darkness, this becomes a larger problem because you lose the help that you normally would get with vision. This becomes a larger problem, a fall risk, if you also lose function in the inner ears.

Signs and symptoms of hearing loss

One might experience a few or a combination of symptoms.

  • Speech and other sounds are perceived muffled.
  • Difficulty understanding words or speech in a presence of background noise or crowd.
  • Frequently asking other to speak more slowly, clearly and loudly.
  • Constantly turning the TV/radio volume up.
  • Often withdrawing from conversations.
  • Avoiding certain social settings.

How to protect your hearing and balance?

You might have not yet experienced symptoms related to hearing and balance, but prevention is better than cure. Take charge of your diabetes by:

  • Controlling your blood sugar by taking your prescribed medication.
  • Noise can damage your hearing. At home, wear ear plugs when you are running the lawn mower or any other loud appliance. Take ear plugs with you when you attend concerts and sporting events that may be too loud.
  • Have your hearing tested by an audiologist on a regular basis. At least annually or sooner if you notice changes.
  • If you have a hearing impairment, your audiologist might fit you with hearing devices that will improve your ability to converse with others (e.g. hearing aids and assistive hearing devices).
  • Reduce background noise when you have a conversation (radio, TV, etc.)
  • Your doctor may recommend that your inner ears be evaluated by an audiologist to diagnose why you are dizzy and whether it is vertigo. Referrals will be made to other professionals, such as physiotherapists and occupational therapist.
  • Work with your doctor to determine whether changes in your medications might explain changes in your balance.


The Audiology Project

Bainbridge, K., Hoffman, H., & Cowie, C. (2008). Diabetes and Hearing Impairment in the United States: Audiometric Evidence from the National Health and Nutrition Examination Survey, 1999 to 2004. Ann Intern Med

Akinpelu, O., Mujica-Mota, M., & Daniel, S. (2014). Is type 2 diabetes mellitus associated with alterations in hearing? A systematic review and meta-analysis. Laryngoscope, 767-76.

Arlinger, S. (2003). Negative consequences of uncorrected hearing loss – A review. International Journal of Audiology, 42(2), S17–2 S20.

Hlayisi, V., Petersen, L., & Ramma, L. (2018). High prevelance of disabling hearing loss in young to middle-aged adults with diabetes. Int J Diabetes Dev Ctries, 39(1), 148-153. doi:10.1007/s13410-018-0655-9.


Sakhile Nkosi is an audiologist in the public sector. He has been exposed to lots of conditions that are in line with the global burden of diseases, one of them is diabetes. Currently, Sakhile holds a portfolio as a public sector representative at the South African Association of Audiologists (SAAA) and is also part of The Audiology Project (TAP), South African Cohort. 

Screen for life – know your score

We hear why diabetic retinopathy screening, Screen for life, is so important for diabetes patients.

Modern technological advances have made it possible to detect the earliest signs of diabetic disease by taking a photograph of the retina at the back of the eye. A new appreciation of the importance of the detection of any retinopathy has changed the way doctors are managing the disease.

The detection of retinopathy, done by human and artificial intelligence graders, informs the risk of future disease, including blindness. This makes it imperative for people living with diabetes to know their retinopathy score while there is still time to change it by looking after themselves better.

#Redflag communication system

The Ophthalmology Society of South Africa (OSSA) has developed the Screen for life programme to help communicate these important messages, using three red warning flags. The #Redflag communication system is communicated using the patient held record:

  • Screen for life, #Flag 1: Detection of any retinopathy determines the person to be retinopathy positive. This increases the risk of future complications, especially heart attack. The primary care giver needs to be informed of this.
  • Screen for sight, #Flag 2: Detection of sight-threatening retinopathy, glaucoma, and age-related macular degeneration. Referral to an ophthalmologist is indicated for this.
  • Screen for progression, #Flag 3: Progression of retinopathy disease means that the steps to control the disease are not working and more help is needed to prevent severe disease. This will require more urgent intervention by the primary care giver and may require referral to a diabetologist.

All people living with diabetes should be screened to determine whether retinopathy is present. If no retinopathy is detected, the person is advised to be screened in one year’s time. Diabetic patients are encouraged to keep looking after themselves well to stay retinopathy negative. When retinopathy is present, review is advised based on the severity of disease detected. This may be yearly, six-monthly or three-monthly. Once retinopathy is more severe, referral to an ophthalmologist is indicated.


Stephen Cook is an ophthalmologist and works at the Eye Centre which strives to provide a comprehensive eye service to people in the region. He is also a part-time consultant at the Frere Hospital and supports the registrar training programme for Walter Sisulu University. His special interests lie in making medical services more accessible and communication regarding conditions more understandable. He has developed the Screen for life diabetic retinopathy screening programme on behalf of the ophthalmology society (OSSA).

Coconut oil – is it what it is set out to be?

The claimed health benefits of coconut products are in abundance, but how much of this information is true? Dietitian, Jessica Oosthuizen, tells us.

Coconut products are abundant on the shelves of supermarkets and health stores. These products promise so many health benefits. Apart from coconut oil, you will find coconut milk, coconut water, coconut yoghurt and coconut snack bars just to name a few.

If you Google the health benefits of coconut oil, the websites and lists will be endless. Claims for coconut oil will vary from increasing fat burning; reducing hunger therefore help you to eat less; ability to raise your ‘good’ HDL cholesterol; protection of skin, hair and dental health; reducing inflammation; and stimulating organs, such as the thyroid and the brain, to assist in weight loss. Let’s take a further look at the health claims.

  1. Coconut oil lowers your risk for heart disease

There are claims stating that populations who eat a lot of coconut oil are healthy. Such as those in India, Sri Lanka and countries in the South Pacific area. However, when evaluating these claims, it’s important to remember that there are various factors other than cholesterol that contribute to one outcome, such as heart disease.

The overall diet will play a key role towards how nutrients influence health outcomes. The diet consumed by these populations will contribute to their minimal risk for developing heart disease, as their diet is mostly unprocessed, and rich in wholegrains, fish and fresh fruit and vegetables. This type of diet contrasts with the typical Western diet – high in refined carbohydrates, sugars and saturated fats.

Clinical trials comparing the direct effect on cardiovascular disease (CVD) of coconut oil have not been reported. Therefore, there is no scientific evidence stating that coconut oil can reduce your risk for CVD.

Many studies have evaluated the effect of consuming a variety of fats and oils on blood lipid profiles, including coconut oil, butter, coconut butter and unsaturated fats (olive oil, sunflower oil, safflower oil and corn oil). Coconut oil raised both HDL and LDL cholesterol.

Numerous studies have shown that you can lower your risk of heart disease by replacing saturated fats with unsaturated fats in the diet. Individuals who adopt the Mediterranean style of eating that includes nuts, olives and olive oil had a lower risk for developing heart disease, stroke and death compared to those who follow a low-fat diet.

  1. Coconut oil is healthy as it contains medium-chain triglycerides (MCT)

All dietary fats consist of a variety of fatty acids. Depending on the length of the fatty acid chain, fatty acids are classified as short-, medium- or long-chain fatty acids. MCTs are easily digested and absorbed by the body.

The truth lies in the fact that lauric acid, which is the predominant property in coconut oil, has a higher molecular weight and is metabolised differently to the lower-molecular-weight triglycerides, such as caprylic and capric acids.

Most MCT fats are made up of caprylic and capric acids and not the lauric acid found in coconut oil. Since the triglycerides that are present in coconut oil cannot biologically or functionally be classified as MCTs, it is incorrect to apply these health benefits of coconut oil as the research is not relevant.

  1. Coconut oil is better to use for cooking

It’s imperative to understand the smoke point of certain types of oil when determining if it is suitable for cooking. The smoke point refers to the temperature that the oil can be used in cooking. The higher the smoke point, the more cooking methods it can be used for. The smoking point of coconut oil is 177°C compared to healthier options, such as virgin olive oil which has a smoking point of 210°C; sunflower oil (227°C) and canola oil (204°C).

The conclusion on coconut oil

The evidence showing an association between coconut consumption and risk factors for heart disease is mostly of poor quality. However, it does show that coconut oil compared to unsaturated plant oils raises total cholesterol, HDL cholesterol and LDL cholesterol. There is no convincing evidence to support the benefits of consuming coconut oil. Research suggests that replacing coconut oil with unsaturated fats, such as olive oil, could reduce your CVD risk.

With this said, it does not mean that all coconut products need to be completely avoided. They can add flavour to the occasional Thai or Indian dish.

When selecting an oil to use every day, it would be best to choose an unsaturated fat, such as olive oil. The World Health Organisation (WHO) recommends reducing saturated fats to <10% of total energy intake. Practically speaking for a man following an 8400kJ (2000kcal) diet, 10% of this would be 22g of saturated fat per day. One tablespoon of coconut provides 12g of saturated fat. Therefore, you can get an idea of how easy it is to reach your saturated fat intake for the day if using coconut oil. As a comparison, 1 tablespoon of olive oil only has 2g of saturated fat and 10g of monounsaturated and polyunsaturated fatty acids.


  1. Sacks et al. (2017). Dietary fats and Cardiovascular Disease. A Presidential Advisory from the American Heart Association. Circulation. 135 : e00-23.
  2. Clifton, P.M. & Keogh, J.B. (2017). A systematic review of the effect of dietary saturated and polyunsaturated fat on heart disease. Nutrition, Metabolism & Cardiovascular Diseases. 27:1060-1080.
  3. Eyres, L., Eyres, M.F., Chisholm, A. & Brown, R. C. 2016. Coconut oil consumption and cardiovascular risk factors in humans. Nutrition Reviews. 74(4):267-280.
  4. World Health Organisation. Practical advice on maintaining a health diet : Fats. 2018.


Jessica Oosthuizen RD (SA) is a Type 1 diabetic herself (since the age of 13). She has a special interest in the nutritional management of children and adults with diabetes. She also has a key interest in weight management and eating disorders. Her experience includes working in the clinical hospital setting as well as experience with a variety of chronic diseases of lifestyle, such as obesity, hypertension and Type 2 diabetes.

Making insulin work for the diabetic, and not the other way around

Michelle Carrihill educates us on how to use various insulins with their unique actions to meet the desired requirements.

There is no ‘easy-peasy’

As a student, I remember being taught that the only thing wrong with a Type 1 diabetic is that they are deficient in insulin. So, the treatment is simple – replace the insulin, and all is returned to normal. Easy-peasy.

Except it is not. Each person is an individual. Each person has variable insulin requirements, and these may change minute-to-minute, hour-to-hour, day-to-day, week-to-week, and especially year-to-year as the body grows and changes.

Very few people have predictable, regular lives. Nevermind predictable regular metabolic rates. Add the variability that is introduced with different amounts and types of carbohydrates, plus protein and the altered absorption with fat in a meal; throw in exercise, emotions and stress, and it might feel almost impossible to exactly figure out which insulin and how much of it should be given at any one time.

Another factor is that each individual may respond slightly differently to a brand or type of insulin, and that the individual’s response may not be the same at each injection.

Also, unlike the insulin produced naturally, once insulin is injected in the body, it cannot be switched off. Once it is in the body, it will continue working, whether needed or not!

Individualise insulin treatment

The most important thing is to individualise the insulin treatment regimen to best fit the individual’s needs. Obviously, the available insulins, the budget and the willingness of the diabetic (or their carer) to test sugar levels and adjust doses are important to take into consideration when designing insulin replacement therapy.

To understand this, let’s look at the available insulins, and their action times. This information is provided by each of the manufacturers.


Type of Insulin & Brand Names




Role in Blood Sugar Management


Lispro (Humalog) 15-30 min. 30-90 min 3-5 hours Rapid-acting insulin covers insulin needs for meals eaten at the same time as the injection.
Aspart (Novorapid) 10-20 min. 40-50 min. 3-5 hours
Glulisine (Apidra) 20-30 min. 30-90 min. 1-2 1/2 hours


Regular (R)


Biosulin R

Humulin R

Insumam R

30 min. -1 hour 2-5 hours 5-8 hours Short-acting insulin covers insulin needs for meals eaten within 30-60 minutes



Biosulin N

Humulin N

Insumam N




1-2 hours



4-12 hours

18-24 hours Intermediate-acting insulin covers insulin needs for about half the day or overnight.


Insulin glargine (Basaglar, LantusToujeo, Optisulin) 1-1 1/2 hours No peak time. Insulin is delivered at a steady level. 20-24 hours Long-acting insulin covers insulin needs for up to one full day.
Insulin detemir (Levemir) 1-2 hours 6-8 hours Up to 24 hours
Insulin degludec (Tresiba) 30-90 min. No peak time 42 hours


Humulin 30/70


30 min. 2-4 hours 14-24 hours These products are generally taken twice a day before main meals.
NovoMix 30 10-20 min. 1-4 hours Up to 24 hours
Humalog mix 25 15 min. 30 min.-2 1/2 hours 16-20 hours
*Premixed insulins combine specific amounts of intermediate-acting and short-acting insulin in one bottle or insulin pen. (The numbers following the brand name indicate the percentage of each type of insulin.)

If you combine these insulin profiles, and superimpose them over what the individual’s insulin requirements are, you then get to understand when the insulin will be working for them, and which combination will suit their needs. These needs may vary from time-to-time and over time, so it is important they monitor their sugars, either with finger-prick tests, or if viable, a continuous glucose monitor.

Let’s look at some regimens:

Twice a day insulin

Benefits: Disadvantages:
Easiest regimen Must be given 30 minutes before the meals.
Only two injections a day Midmorning snack required.
Lunch carbohydrates may not be adequately covered.
No flexibility in meal component of the insulin (if using a premixed insulin combination).
The intermediate-acting insulin given before an early dinner may mean inadequate basal cover by the early morning – a risk of waking up with a high fasting sugar, and some ketosis.

 Three times a day insulin

Benefits: Disadvantages:
Covers overnight requirements better by the later injection of the intermediate insulin, decreasing the chance of morning high levels. Regular insulin must be given 30 minutes before the meals.
Midmorning snack required.
Lunch carbohydrates may not be adequately covered.
Requires a bedtime snack.

 Basal bolus regimen

Benefits: Disadvantages:
Flexible dosing for carbohydrates and correcting. In-between meal carbohydrates need to be counted and dosed for. Or carbohydrate free snacks considered.
More frequent injections (and testing) required.
More expensive.

 Long-acting insulin analogues

Benefits: Disadvantages:
Flexible dosage for carbohydrates and correcting. ‘In-between’ meal carbohydrates need to be counted and dosed for. Or carbohydrate free snacks considered.
Fasting is possible. More frequent injections (and testing) required.
Flexibility in the timing of the meals/snacks. Much more expensive.
Less risk of nocturnal hypoglycaemia.
No need for night time snack.

Continuous sc insulin infusion

Benefits: Disadvantages:
Built in calculator for carbohydrate counting and corrections. Only rapid insulin is used, so any disruption in delivery can rapidly lead to ketoacidosis.
Insulin can be suspended. Very expensive.
Basal rates can be individually set. Needs high quality training and ongoing interaction.
Dawn phenomenon can be covered. Permanently attached to a device.
Fasting easy to achieve.
Temporary increase or decrease in basal requirements easy to achieve.

Mix and match

Mixing and matching of insulins is also possible. For example, a child attending primary school might do well on regular and intermediate-acting insulins half an hour before breakfast, without requiring any insulin for their school break; a rapid insulin analogue for after-school lunch and dinner; and then a long-acting basal analogue for their basal insulin overnight.

As mentioned already, monitoring the blood glucose then opens the eyes to the effect of the insulin doses – both for the individual dose, as well as for the pattern of dosing. Fasting sugars reflect the long-acting doses and post-meal levels reflect the bolused doses for carbohydrates and corrections.

Carbohydrate counting affords the closest-to-physiology use of mealtime insulin, and is to be encouraged. Even if using a fixed-dose insulin regimen, knowing how much carbohydrate is in a meal allows for consistency of insulin to carbohydrate dosing – which then helps prevent sugar variability after meals.

Monitoring sugar levels before and after activities and sports helps with planning of extra carbohydrates or a change in insulin dose for the meal before or after the exercise.

The message is that getting sugars to target is possible by knowing what the individual needs, and using the available insulins to suit those needs. Monitoring sugars and adjusting doses and types of insulin along the way will keep the person with diabetes healthy, and able to get on with living their lives.


Dr Michelle Carrihill is a paediatric endocrinologist working with children and adolescents with diabetes and chronic endocrine and metabolic conditions. She runs the adolescent sub-speciality ward at Groote Schuur Hospital and has a large ambulatory service for the chronic medical needs of these patients.