Dr Angela Murphy shares one of her patient’s stories to explain the connection between diabetes and gastroparesis.
Ms DL is a 28-year-old lady, who was diagnosed with Type 1 diabetes at the age of 15. She had poor control from the start due to not being able to accept the diagnosis. She was admitted regularly with diabetic ketoacidosis, with extreme dehydration. During these episodes, she would go into renal failure. Closer questioning revealed that symptoms would begin with nausea and vomiting. She had been experiencing bloating after meals for over a year. A gastric emptying study was done, which showed significant gastroparesis.
What is gastroparesis?
It is a condition where the stomach does not empty properly, resulting in food not moving into the small intestine. Normally, the muscles of the entire gastrointestinal tract contract and release rhythmically to move food along, which is necessary for the digestive process. This muscle action is controlled by the vagus nerve. However, damage to the vagus nerve results in weaker, poorly contracting muscles and slows the movement of food out of the stomach.
Unfortunately, there are many causes – it can occur as a complication of surgery to the gastrointestinal tract; as part of neurological disorders; infective and inflammatory conditions; or in underactive thyroid disease. Over a third of cases are due to diabetes, and in some cases no specific cause can be found.
Poorly controlled diabetes can result in damage to the vagus nerve, and is the most common known cause of gastroparesis. Patients classically present with stomach pain, bloating, indigestion, nausea and vomiting. In an insulin-dependent diabetic patient, vomiting will lead to ketones, and the presentation may look like an episode of ketoacidosis. In addition, patients may have documented reflux disease or irritable bowel syndrome (IBS), and the symptoms may be attributed to these conditions. A careful examination and history is needed to work out the sequence of events.
Ms DL had a variety of tests to diagnose her problem, such as:
- Upper gastrointestinal gastroscopy is performed by either a gastroenterologist or a surgeon, and can be carried out as an outpatient. The patient fasts for six hours, then a flexible camera is used to look inside the oesophagus, stomach and the duodenum (the first part of the small intestine).
- Barium meal and follow-through is when a patient must fast for eight hours and then drinks barium – a chalky type liquid – that is used as the contrast agent. A series of X-rays are then taken. Barium lines the gastrointestinal tract so will show any obstruction, such as food in the stomach, quite clearly on the X-ray.
- Ultrasound allows the radiologist to exclude any disease of the gallbladder or pancreas.
- Gastric emptying scintigraphy is usually the gold standard for diagnosis. The patient fasts from the night before and is then required to eat a bland meal which is radiolabelled with technetium. A camera then scans the abdomen to follow the progress of the radiolabelled food hourly for four hours after a meal. If more than 10% of the meal is in the stomach after four hours, the diagnosis of gastroparesis is made.
Ms DL was started on domperidone (prokinetics) and erythromycin (antibiotic). After 10 months, the episodes returned despite medical treatment. She then had a gastric pacemaker inserted, which only seemed to give benefit for six months. Ms DL recently spent weeks in hospital being treated with anti-nausea medication and intravenous fluids. Unfortunately, there was no way to improve the result with the pacemaker so she was given the option of Botox injections; however, the relief in symptoms after this was very short. After almost two years of suffering, Ms DL underwent a sleeve gastrectomy. (See medical explanations below).
- Prokinetics are drugs that improve the contraction of the stomach muscles, and move food through to the small intestine more effectively.
- Metoclopromide is the active ingredient in Maxalon and Clopamom. This should be taken 20-30 minutes before meals. It helps reduce nausea and vomiting. Although it is approved for gastroparesis, it may have side effects, such as tardive dyskinesia – a movement disorder which causes shaking.
- Erythromycin is an antibiotic. When it is prescribed chronically at low doses, it improves stomach muscle contractions. Unfortunately, it can also cause nausea and stomach cramps which limits its use in the gastroparesis patient.
- Anti-emetics are anti-nausea drugs.
- Prochlorperazine (Stemetil) is useful when the patient is acutely ill, however, it has even more side effects with chronic use than metoclopramide.
- Antipsychotic drugs
- Chlorpromazine (Largactil) has frequently been used in patients with severe, persistent hiccups. Its actions on muscle have also worked in the patient with gastroparesis with some degree of success.
- Botulinum toxin is used when a gastroenterologist injects Botox directly into the pylorus (the valve between the stomach and duodenum involved in the rate of gastric emptying) using an endoscope. This relaxes the valve, keeping it open for longer periods allowing food to pass through. The results of Botox are quite variable; some patients have relief of their symptoms for months, while others find no improvement.
- Gastric pacemaker is a neurostimulator device which can be surgically implanted. This is normally done in patients with symptoms not responding to medication and diet changes. The battery-operated device has electrodes that are inserted into the stomach muscle wall. This then sends signals at regular intervals to stimulate the stomach muscle. Studies have found that sending pulses that have a higher frequency than normal gastric contraction improves nausea and vomiting more effectively. However, more work needs to be done to refine this treatment for patients.
- Jejenostomy is a feeding tube which is placed through the abdominal wall directly into the jejunum (the second section of the small intestine). Special, balanced liquid food can then be given to the patient. It is commonly used in a malnourished, dehydrated patient.
- Sleeve gastrectomy is a near total gastrectomy performed via keyhole surgery.
- Roux-en-Y gastric bypass is when a small pouch is made from the top of the stomach and is attached to a loop of jejunum.
In both these surgeries, by removing most of the functional stomach it is possible to relieve symptoms of nausea and vomiting. Patients must be well-prepared, even though the dietary changes required are essentially the same as they should be following: small regular meals (see info on diet below).
Surgery is the treatment of last resort, but in my patient, this was life-changing. In the months post-surgery, she has had fewer and fewer episodes of vomiting. Generally, her symptoms have declined and her quality of life has improved incredibly.
There are several useful measures patients can take to improve symptoms:
- Eat six small meals a day; this gives the stomach a chance to empty.
- Limit the amount of fatty foods.
- Limit fibre as it also takes longer to digest.
- Eat in an upright position.
- Avoid late evening meals.
- Avoid carbonated drinks.
- If the patient is very symptomatic then a liquid diet is the best choice until improvement.
Gastroparesis and diabetes
There is no doubt a vicious cycle exists when diabetes and gastroparesis occur together; high blood glucose directly slows down gastric emptying. Poor diabetes control for more than 10 years increases the risk of damage to the autonomic nervous system. The autonomic nerves control the automatic functions of the body, such as heart beat, blood pressure and gastric emptying. The erratic emptying of food into the small intestine makes timing of insulin doses very difficult, and patients often swing from high to low blood glucose levels. It may be necessary to change the insulin regimen to get better control, and frequent blood glucose testing is vital.
Gastroparesis severely impacts a patient’s quality of life. Most patients with gastroparesis will respond to dietary changes, prokinetics and erythromycin. However, for those that don’t, it is important to pursue more invasive treatment until relief of symptoms is achieved.