The renin-angiotensin-aldosterone system in diabetic patients with hyperkalemia

Seven long-standing diabetic patients with spontaneous and intermittent hyperkalemia were studied in an effort to assess the normality of their renin-aldosterone axis. The administration of oral glucose, in the absence of insulin, caused a paradoxical rise in serum potassium with no significant change in plasma aldosterone concentration from controls. All displayed subnormal aldosterone-secreting capacity to known stimuli of aldosterone secretion such as low salt diet, angiotensin II infusion, and ACTH infusion. The paradoxical rise in serum potassium with hyperglycemia was corrected in all by concomitant administration of insulin or pretreatment with a mineralocorticoid. Our observations question the role of aldosterone deficiency in the phenomenon of glucose-induced hyperkalemia.