[Diseases of the cardiovascular system and the function of the endocrine glands in veterans of Soviet Antarctic expeditions].

The authors examined 58 men who had repeatedly participated in the Antarctic expeditions. In addition to a profound study of the cardiovascular system, the insulin tolerance test (0.1 U/kg simple insulin injected by intravenous drip for 90 minutes) was made, permitting the degree of tissue insulin resistance to be quantitatively estimated with measurements of the content of cyclic nucleotides in blood leukocytes and of immunoreactive insulin, C-peptide and counterinsular hormones in the blood before and after the functional test. It was established that with the increase of the number of Antarctic winterings tissue insulin resistance naturally grows regardless of the age of the examinees, manifesting itself in an increase of basal insulinemia, the content of cyclic adenosine monophosphate in blood leukocytes, appreciable increment of insulinemia after infusion of exogenous insulin. Analogous changes were detected in polar researchers suffering from coronary disease, essential hypertension irrespective of the number of winterings. It is concluded that the rise of tissue insulin resistance occurring under the influence of multiple exposures to natural and social factors of high latitudes is a predisposing factor of the formation of cardiovascular pathology.