June 29, 2002
Exercise and Sports
Question from Chicago, Illinois, USA:
My eight old son, diagnosed with type 1 diabetes about seven months ago and on twice daily NPH insulin, is consistently hypoglycemic within one hour of taking the insulin even after a meal, although he does get sugars in the high 200s [mg/dl, 11.1 mmol/L]. I am wondering if this insulin is causing not only the lows but the high sugar levels.
Answer:
This is not such a very unusual story which seems to occur occasionally in children who are still producing some of their own insulin and who have rather little subcutaneous fat. The explanation usually offered is that some or all of the insulin is injected intramuscularly where it has a much faster action. This seems particularly to occur after vigorous exercise and thus with the evening dose. The initial remedy should be make absolutely sure that the insulin is injected subcutaneously. The more rapid action of the NPH may also reflect more rapid destruction and hence the later mild hyperglycemia.
DOB
