Hypoglycemia in Diabetes

Hypoglycaemia is a condition in which blood glucose levels is abnormally low. Healthy people usually do not become hypoglycaemic even if they do not eat as the body can utilise its reserves to produce enough glucose to maintain body metabolism.

Hypoglycaemia occurs most commonly in people with diabetes who are treated with medication to lower blood glucose levels. It may also occur in liver disease, excessive alcohol consumption, and in rare conditions such as insulinoma, (a tumour of the pancreas gland).

The blood glucose level at which diabetics on treatment develop hypoglycaemia may vary but they are at risk once blood glucose levels fall below 3.9 mmol/L(70 mg/dL)1. However some may experience symptoms above or below this; hence being aware of the symptoms of hypoglycaemia is important.

The most common symptoms are:

• Tremors
• Sweating
• Palpitations
• Feeling of anxiety
• Hunger
• Headache
• Blurred vision

As the blood glucose falls further more serious complications develop:

• Confusion and abnormal behaviour
• Loss of consciousness
• Fits (seizures)
• Coma

These complications are due to the effects of low glucose levels in the brain (neuroglycopaenia). Severe and prolonged hypoglycaemia may even result in death.

Diabetics on medication which lower blood glucose may develop hypoglycaemia for various reasons:

• Excessive or wrong medication dosage.
• Taking medication while fasting or not having regular meals.
• Excessive exercise after taking medication.
• The elderly who require smaller doses of medication.
• Those with kidney failure as medication may accumulate in the body.
• Excessive alcohol consumption.

Diabetic patients who are on a combination of different types of diabetic medications or those on insulin injections are at a higher risk for hypoglycaemia. Some patients who have suffered hypoglycaemia may develop a fear of it and may stop taking their medication or self-medicate resulting in uncontrolled diabetes with equally serious consequences.

If symptoms suggestive of hypoglycaemia develop in a diabetic patient the blood glucose should be checked immediately if a blood glucose meter is available.

If a blood glucose meter is not available but symptoms of hypoglycaemia are present the patient should be treated as having hypoglycaemia without waiting to confirm the blood glucose level. Treatment should not be delayed as this can be harmful.

For mild hypoglycaemia, where the patient is conscious, something sweet to eat or drink should be given immediately. Many diabetics are able to recognise mild hypoglycaemia and can immediately treat themselves. For those who are drowsy or have lost consciousness there should not be any attempt to force them to take anything by mouth. This is because they may vomit and aspirate stomach contents into the lungs. Such patients should be immediately taken to a clinic or hospital where glucose can be given by intravenous injection.

Following a hypoglycaemic attack the patient should be referred to their doctor for assessment to determine why the hypoglycaemia episode occurred. There may be a need to adjust the dosage or timing of medication, educate the patient or do further investigations.

“Hypoglycaemic unawareness” is a condition where a person has hypoglycaemia yet not experience symptoms. Hence the hypoglycaemic episode goes unrecognised. This may occur in those with frequent hypoglycaemia or in those with longstanding or advanced diabetes who have developed complications in their nervous system (autonomic neuropathy). The danger of hypoglycaemic unawareness is that such patients may develop severe hypoglycaemia, coma or even life-threatening complications. These patients should be reviewed by their doctors and the blood glucose monitored frequently.

In summary hypoglycaemia is a complication of diabetes treatment that patients and their relatives should be aware of. Early recognition of its symptoms and prompt treatment will help avoid serious complications from developing. Following an episode of hypoglycaemia it is advisable to investigate why it occurred in order to reduce the chances of it occurring again.

More information on diabetes and hypoglycaemia can be found at the Malaysian Diabetes Association website http://www.diabetes.org.my/