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.

Signs and symptoms of low glucose levels

Four people living with diabetes tells Barbara Chinyerere what they experience during hypoglycaemia (low blood glucose levels).

What brings blood glucose levels down?

Before I go to what a person living with diabetes feels when they have low blood glucose levels. Let me just indicate what brings their blood glucose levels down.

  • As their day goes by with workload, losing track of time could result in not eating their in-between snack. A simple thing as not snacking could just dip blood glucose levels.
  • A little more insulin which does not balance with the meal eaten could decrease blood glucose levels.
  • Exercise decrease blood glucose levels.
  • A state of shock brings blood glucose levels down.

Different people experience different symptoms

This is not a one size fit all situation. Different people feel different symptoms. Some can see them coming and can feel their lows. Others could be too young to recognise the feelings, but with time they will get to know them. Note: hunger is not one of the signs mentioned with any of the people interviewed.

One-on-one conversations to get a clear view

An 8-year-old, who has had diabetes for four years, is not able to tell when he has low blood glucose levels. Though the warning signs are very visible to the mother. She explainis, “From a very chatty, energetic busybody, he gets sleepy, which does not happen when he has normal glucose levels. Especially, during the day, he becomes quiet and next thing he is fast asleep.

On a bad day, he gets disorientated and doesn’t know whether its day or night. On checking his levels, he had a dip of 2.4mmol/L. Once he passed out and could only be woken up with glycogen. On this occasion, he had been exercising the whole afternoon and passed out into his PT teacher’s arms.

A 48-year-old male said the minute he gets dizzy, it’s a sign for him to go eat something. This happens any time of the day, especially when he has missed a meal. Eating meals and snacks is his priority.

A 60-year-old female, who’s been diabetic for 22 years, gets extremely sweaty, starts to shake and yawns. Her first low, she experienced blurry vision and had tremors in her hands.

A 58-year-old nurse said she never experienced lows anymore. She has mastered eating regular meals and snacks.

Keeping regular meals, and snacks could limit the chances of hypoglycemia, so snack on.


Barbara Chinyerere

Barbara Chinyere is a mother of two sons. Her youngest son was diagnosed with Type 1 diabetes at the age of 3. She says it has been a roller coaster ride but she finds courage because of her son’s strength.

Don’t let glucose levels scare you this Halloween

If your family is planning to go trick-or-treating, Donna van Zyl shares ways to enjoy Halloween without fussing over glucose levels.

Halloween need not only be about the trick-or-treating. Encourage your child to partake in non-food activities, such as carving a pumpkin; make decorations; having fun with friends and family whilst watching a scary movie; dressing up or visiting a ‘haunted’ house. It is, however, important to know what your child is looking forward to on this day, so that you can help meet their diabetes management in the middle.

Plan ahead

Sit down with your family and make Halloween plans in advance so your child knows what to expect. Create boundaries and general rules with your family. Your child will be more likely to be on board with a plan they helped create.

The rules of the plan may include:

  • Make sure your child does not go alone.
  • Ensure your child eats well and smart throughout the day, prior to the trick-or-treating so he/she can start off the evening with normal blood sugar level.
  • Then, make a deal with your child to avoid snacking until you’re both home from trick-or-treating.
  • Your child should take his/her own water or non-sugary drinks along, as they may get thirsty.
  • Your child should keep track of his/her sugar levels throughout the evening. Trick-or-treating may include a lot of excitement, running around or even having a treat out of the extraordinary.
  • Be prepared – test and ensure your child has something appropriate to treat a hypo. It is likely that he/she will have something in their bag to treat a hypo, however, the chocolate containing sweets do not necessarily act rapidly. Ideally, they should choose the sugary option and may need a follow-on snack, like a half of a peanut butter sandwich.
  • Friends and family can be very supportive and have healthy snacks waiting for your child. These options may include nuts, dark chocolate and fruit (strawberries dipped into dark chocolate). If they do have chocolate, encourage them to make sure they’re the snack-size versions.

Returning home

Once both of you have returned home, allow your child to choose his/ her favourite treat and administer an insulin dose accordingly.

The non-chocolate treats could be sorted into 15g carb packets and kept to treat a hypo. Those chocolate coated treats can be exchanged for a desired gift i.e. a toy, TV game, movie ticket, or a trip to the zoo etc. The exchange of sweets for a desired toy or game could apply to all the children of the house. The exchanged treats can also be donated to the less fortunate community groups as a treat they often do not receive.

Diabetic-friendly Halloween recipes

You can also make great Halloween diabetic-friendly recipes that will allow your children with diabetes to enjoy the day, without missing out treats.

Suitable Halloween treats:


Donna van Zyl is a private practicing dietitian for Nutritional Solutions, Bloemfontein. She is growing in the field of paediatrics and plays a key role in individualising nutritional therapy for Type 1 diabetics. She has a special interest in optimising health, managing chronic lifestyle related diseases, and sports nutrition. She lectures part-time at the University of the Free State, which she enjoys thoroughly.

The first flash glucose monitoring system now in SA

The world’s first flash glucose monitoring system, which requires only a scan rather than a traditional finger prick to test blood glucose, is now available in South Africa.

The ability to get a glucose reading with a quick, painless scan has ushered in a new era of bloodless, simple and calibration-free visualisation of glycemic control – the flash glucose monitoring system.

The unique technology replaces blood glucose meters, while giving patients many of the benefits of continuous glucose monitoring (CGM), including real-time glucose values, trend information and comprehensive reports.

The flash glucose monitoring system

This new system includes a flexible filament sensor, which is inserted 5 mm under the skin. The filament is connected to a small, round disc and held in place on the skin with medical adhesive. The sensor remains inserted for 14 days. One hour after application to the upper arm, it begins reading blood glucose levels and continues to do so for up to 14 days.

The hi-tech monitor, first introduced in Europe, has provided unparalleled levels of data so necessary in the management of diabetes and has revolutionised the way people with Type 1 diabetes can manage their glucose levels.

Controlling glucose levels is a prerequisite for treating diabetes. Traditional testing with blood from a fingertip is recommended 4 to 8 times a day.

What the expert says

Dr Larry Distiller, an endocrinologist, says when the technology was first introduced in Europe, a voluntary pilot project was initiated. More than 50 000 people participated in the pilot, between 2014 and 2016, yielding 409 million data points. The analysed data provided invaluable insights into glucose monitoring.

In comparison, the new flash glucose monitoring system allows users to scan and check their blood glucose at any time without any limit. Practically, pilot project participants scanned on average up to 16 times per day. Research found that those who scanned the most had the best control of their blood glucose.

In addition to always being available and providing immediate personal monitoring, the reader data can be downloaded and analysed using specific software. This produces detailed and informative visual outputs on daily glycaemic trends and variability and highlights statistical risks of hypoglycaemia and hyperglycaemia according to the time of day.

Looking into the future

In time, patients will also be able to scan the sensor using their cell phone. Distiller says this new technology is approved for dosing insulin, except in three cases when a finger stick is recommended: when hypoglycaemic, when glucose is changing rapidly, or when symptoms don’t match the system’s readings.

MEET OUR EXPERT - Prof Larry Disteller

Prof Larry Disteller is an endocrinologist.