Glucose metabolism and insulin sensitivity in patients on chronic hemodialysis

In order to evaluate the potential role of parathyroid hormone on glucose metabolism in patients on chronic hemodialysis hyperglycemic clamp studies were performed in 7 parathyroidectomized and 11 nonparathyroidectomized patients on chronic hemodialysis and in healthy controls. There were no significant differences in the peripheral glucose uptake of the 3 groups. The beta cell response to hyperglycemia during the early phase as well as during the steady state was almost identical in controls and in nonparathyroidectomized uremics, whereas in the parathyroidectomized group a markedly enhanced insulin secretion was found. Calculated tissue sensitivity to insulin therefore was equal in controls and in nonparathyroidectomized uremics, whereas patients after parathyroidectomy had peripheral insulin resistance. Our results demonstrate that patients on chronic hemodialysis apparently have normal peripheral glucose uptake. The subgroup of patients who have undergone parathyroidectomy, however, show an enhanced insulin response to hyperglycemia suggesting peripheral insulin resistance. We conclude that longstanding and severe secondary hyperparathyroidism--the usual cause for parathyroidectomy in these patients--results in irreversible insulin resistance with a compensatory increase of insulin secretion.