In long-standing type 1 diabetes, it is common that symptoms of low blood sugar either become diminished or change. The secretion of hormones that increase the blood sugar level is reduced. The glucagon response is reduced or missing. The adrenaline response is also reduced, blunting the warning symptoms that normally come first. If there is change in how you sense the low blood sugar levels, it is important for you to learn to recognise the new symptoms as being caused by low blood sugar levels so that you can react to the situation early enough.
If the symptoms become reduced, it may also be a sign of your blood sugar balance being too “tight”. If the HbA1c level in insulin therapy is below 48 mmol/mol (6,5%), glucose sensing should be used to ascertain the frequency of the low blood sugar levels. If hypoglycaemia occurs on a regular basis at a specific time of the day, you should either reduce the dose active at that time or change the time you take the dose.
If your blood sugar is constantly low – especially if it is below 3 mmol/l – your body “gets used to” the low blood sugar level. This leads to your body's systems becoming slow to react, the adrenaline-related insulin sensations diminishing and the neurological symptoms becoming the first symptoms of a low blood sugar, occurring at even lower blood sugar level. This further increases the risk of dangerously low blood sugar.
If the hypoglycaemia symptoms are permanently reduced, the recommendation is to use a glucose sensor with an alarm function. It may be necessary to slightly increase the target blood sugar range to, for example, 5–8 mmol/l in the morning and before meals and 8–10 mmol/l at bedtime.