Labile diabetes

Insulin-dependent diabetes characterized by dramatic and recurrent swings in glucose levels, often occurring for no apparent reason, is sometimes known as brittle diabetes, unstable diabetes or labile diabetes, although some experts say the "brittle diabetes" concept "has no biologic basis and should not be used".^[87] The results of such swings can be irregular and unpredictable hyperglycemias, sometimes involving ketoacidosis, and sometimes serious hypoglycemias. Brittle diabetes occurs no more frequently than in 1% to 2% of diabetics.^[88] In a small study, 10 of 20 brittle diabetic patients aged 18–23 years who could be traced had died within 22 years, and the remainder, though suffering high rates of complications, were no longer brittle.^[89] These results were similar to those of an earlier study by the same authors which found a 19% mortality in 26 patients after 10.5 years.^[90]
Because labile diabetes is defined as "episodes of hypoglycemia or hyperglycemia that, whatever their cause, constantly disrupt a patient's life", it can have many causes, some of which include:^[91]

• errors in diabetes management, which can include too much insulin being given, in relation to carbohydrate being consumed
• interactions with other medical conditions
• psychological problems
• biological factors that interfere with how insulin is processed within the body
• hypoglycemia and hyperglycemia due to strenuous exercise; however, hypoglycemia is more frequent
• insulin exposed to higher temperatures that reduces effectiveness of the insulin hormone in the body
• spontaneous production of insulin in the body due to activity in the beta cells during the period shortly after diagnosis of type 1 diabetes

Exercise related hyperglycemia is caused when hormones (such as adrenaline and cortisol) are released during moderate to strenuous exercise. This happens when the muscles signal the liver to release glucose into the bloodstream by converting stored glycogen into glucose. The cause of exercise related hypoglycemia, on the other hand, occurs when the muscle group being exercised uses up glucose faster than it can be replenished by the body.
One of these biological factors is the production of insulin autoantibodies. High antibody titers can cause episodes of hyperglycemia by neutralizing the insulin, thereby causing clinical insulin resistance requiring doses of over 200 IU/day. However, antibodies may also fail to buffer the release of the injected insulin into the bloodstream after subcutaneous injection, resulting in episodes of hypoglycemia. In some cases, changing the type of insulin administered can resolve this problem.^[91] There have been a number of reports that insulin autoantibodies can act as a "sink" for insulin and affect the time to peak, half-life, distribution space, and metabolic clearance, though in most patients these effects are small.^[92]