REDUCED SERUM DEHYDROEPIANDROSTERONE LEVELS IN DIABETIC-PATIENTS WITHHYPERINSULINEMIA

OBJECTIVE To elucidate the interaction between insulin and dehydroepi- androsterone (DHEA) concentrations, we evaluated serum DHEA and DHEA-s ulphate (DHEA-S) levels in diabetic patients with hyperinsulinaemia, P ATIENTS AND DESIGN Twenty-four subjects with noninsulin dependent diab etes mellitus, 12 hyperinsulinaemic subjects (fasting serum insulin co ncentrations greater than or equal to 10 mU/ml (71.8 pmol/l)) and 12 n on-hyperinsulinaemic subjects, and 10 normal control subjects were stu died, Serum DHEA, DHEA-S, cortisol and ACTH levels were investigated i n these subjects, Moreover, their serum DHEA levels were compared duri ng hyperinsulinaemic-euglycaemic clamp and after ACTH stimulation, MEA SUREMENTS Serum insulin, cortisol, ACTH, DHEA and DHEA-S concentration s were evaluated by RIA, Serum glucose was determined by the glucose o xidase method, RESULTS Diabetic patients with hyperinsulinaemia showed significantly lower levels of serum DHEA and DHEA-S than controls, Af ter ACTH stimulation, these patients also showed significantly lower D HEA levels. During the hyperinsulinaemic-euglycaemic clamp, serum DHEA concentrations of diabetic patients with hyperinsulinaemia remained l ow and did not decline further, although those of control subjects and non-hyperinsulinaemic diabetic patients showed a significant decline of serum DHEA levels. Even after ACTH stimulation during the clamp, er sum DHEA in hyperinsulinaemic patients was still significantly lower t han in controls, CONCLUSIONS In diabetic patients with hyperinsulinaem ia, baseline DHEA levels are chronically and maximally suppressed comp ared to control subjects and non-hyperinsulinaemic diabetic patients, and thus not decreased further by exogenous insulin infusion during hy perinsulinaemic-euglycaemic clamp.