Diabetes mellitus with hyperparathyroidism: Another indication for parathyroidectomy?

Background. Patients with hyperparathyroidism have alterations in carbohydr ate metabolism characterized by insulin resistance, hyperinsulinemia, and g lucose intolerance. The clinical significance of these findings in the mana gement of patients with diabetes mellitus (DM) after parathyroidectomy for hyperparathyroidism has been controversial. Methods. A retrospective review identified 87 patients with DM and hyperpar athyroidism who underwent parathyroidectomy. The follow-up documentation of 70 patients who underwent diabetic management was then evaluated to assess the benefit of parathyroidectomy on glucose management. Results. Thirteen patients had type I DM, and 74 patients had type 2 DM. Pr imary hyperparathyroidism was present in 93% of patients with type 2 DM; 64 % of patients with type 1 DM had secondary hyperparathyroidism. At follow-u p, glucose control was stable in 40% of patients, had improved in 37% of pa tients, and had deteriorated in 23% of patients (P = .003). Improved glucos e control was not dependent on age, duration of DM, duration of hyperparath yroidism, length of follow-up, or calcium levels. The patients with decreas ed requirements had a significantly lower parathyroid hormone level (P = .0 5). Improved glucose control was most significant in patients whose conditi on was managed with oral hypoglycemics (P = .05) or insulin (P = .03). Conclusions. The clinical and laboratory investigations on the influence of hyperparathyroidism on DM support the benefit of parathyroidectomy in Pati ents with DM. Patients with type 1 and type 2 DM show improvement in glucos e control after parathyroidectomy. The presence of DM and hyperparathyroidi sm is an indication for parathyroidectomy because it results in either stab ilization or improved glucose control in 77% of patients.