Glucose Metabolism in Subjects With Aldosterone-Producing Adenomas

The week of each study period, subjects will be provided a standard 160mmol/d sodium diet for 6-8 days to control for inter-individual sodium intake. In period 1, subjects will report after 5 days of controlled sodium diet for a hyperglycemic clamp study (to measure insulin secretion). Subjects will continue the study diet, and then return for a hyperinsulinemic-euglycemic clamp study (to measure insulin sensitivity). After completion of period 1 assessment, subjects will undergo adrenalectomy by our endocrine surgeons or initiate medical treatment, according to routine clinical care. In period 2, the investigators will repeat the studies in the same manner as period 1, 3 to 12 months after adrenalectomy or initiation of medical treatment.