Effect of verapamil on insulin response to alcohol hypoglycemia in patients with primary hyperparathyroidism.

In hypercalcemic patients with primary hyperparathyroidism who were fasted over a prolonged period, alcohol ingestion induced a significant fall in glucose whereas insulin remained unchanged. The hypercalcemic patients thereby differed from normocalcemic subjects, who showed a significant decline in both glucose and insulin when alcohol was ingested after a prolonged period of fasting. An increased uptake of calcium into the beta-cells appears to have been a prerequisite for the occurrence of an unchanged insulin secretion during alcohol hypoglycemia in hypercalcemic patients, since a calcium-blocking agent, verapamil, infused intravenously during and after alcohol ingestion, brought about a normalization of the insulin response to alcohol hypoglycemia in such patients.