MOST OF US have experienced symptoms of hypoglycaemia or low blood sugar. These may include weakness, tremors, dizziness, palpitations, anxiety and hunger. The commonest triggers for these unpleasant symptoms are stress or sudden shock, unaccustomed exercise, a missed or delayed meal, excessive coffee or alcohol intake, and in women, the 4-5 day premenstrual effect. Frequently there exists a combination of 2 or more of these factors.
Although a sudden fall in the blood sugar can be responsible for some of the above symptoms, the more unpleasant acute symptoms associated with low blood sugar are in fact caused partly by the release into the blood of the hormone adrenalin. This hormone, which is released by the paired adrenal glands situated over each kidney, serves to convert into glucose the carbohydrate reserves held in the liver, and known as glycogen. In this way undesirably low levels of glucose in the blood are quickly corrected. Although this adrenal compensation is triggered when the blood glucose is too low, the same response can occur when the blood glucose level falls too quickly.
Adrenalin is also released to help the body combat stress. In addition to the blood sugar surge, this hormone increases the heart rate and raises the blood pressure. The rate of respiration is also increased; in fact the whole metabolism is ârevved-upâ. This has been termed the âflight or fightâ response, and can be compared to pulling out the choke on a car, causing an increase in available fuel and accelerating the engine.
The hunger experienced with low blood sugar is usually expressed as a sugar craving (particularly pre-menstrually), and all the symptoms rapidly improve after taking sugar in food or drink. If the various components of the sugar-regulation system are working efficiently our body chemistry is rapidly normalised. This phenomenon is known as transient hypoglycaemia, and such infrequent and temporary slumps in the blood sugar level do not normally require special diets or treatment.
Unfortunately there are those who suffer a more chronic, severe and reoccuring form of low blood sugar, known as functional hypoglycaemia. This condition was first described in the late 1920s by an American doctor named Seale Harris. His contemporaries Banting and Best had recently discovered and refined the hormone insulin for the treatment of diabetes. Insulin-dependent diabetics can occasionally overdose on insulin, causing a sudden undesirable fall in the blood sugar. This was termed a âhypo effectâ, and caused symptoms including faintness, dizziness, anxiety and if severe, a temporary collapse and unconsciousness.
Dr Harris observed that several of his non-diabetic patients were experiencing very similar symptoms to patients attending the new diabetic clinics. This led him to conclude that if non-diabetics were suffering âhyposâ (or insulin shock), then perhaps there existed a medical condition that was opposite in character to high blood sugar in diabetes. He called this new condition hyperinsulinism, (excess insulin in the blood), and assumed that just as diabetics suffer an insulin deficiency resulting in high blood sugar, there are those who suffer an excess causing low blood sugar. Although high and low blood sugar appear to be opposite conditions, they are both caused by defective or inefficient blood sugar regulation.