Smoking reduces insulin absorption from subcutaneous tissue.

The degree of glycaemic control in insulin-dependent diabetic patients is highly influenced by the rate of insulin absorption from subcutaneous tissue to blood. We have recently shown a correlation between subcutaneous blood flow and insulin absorption.' Smoking increases the concentration of catecholamines in the blood.2 In normal subjects inhaling cigarettes produces a transient rise in blood pressure and pulse rate and a fall in skin temperature. The peripheral vasoconstriction lasts from several minutes to more than one hour, and habitual smokers do not show tolerance to smoking by a decrease in these effects.3 The duration of peripheral vasoconstriction caused by smoking might, therefore, have an effect on insulin absorption. We tested this hypothesis.