Effect of insulin-induced hypoglycaemia on absorption of unmodified insulin after subcutaneous or intramuscular injection.

The effect of insulin-induced hypoglycaemia on the absorption of iodine-125 labelled unmodified insulin (10 U) from thigh after subcutaneous or intramuscular injection was studied in eight immobilized, supine, normal subjects. Ultrasonic determination of the subcutaneous thickness was used to accurately localize the site for insulin injection. Insulin absorption was studied twice during hypoglycaemia or normoglycaemia in random order. Insulin absorption was similar after subcutaneous and intramuscular injections (residual activity at 5 h: SC 59.3 +/- 5.0 (+/- SE) %; IM 55.2 +/- 3.7%). Hypoglycaemia did not change the disappearance rate of iodine-125 insulin after either subcutaneous (55.0 +/- 4.4%) or intramuscular injection (52.6 +/- 5.7%), despite a plasma glucose nadir of 1.7 +/- 0.2 mmol I-1. In a controlled study under standardized conditions hypoglycaemia has no effect on insulin absorption rate.(ABSTRACT TRUNCATED AT 250 WORDS)