Hypoparathyroidism in diabetes mellitus

Abstract

Abstract. Serum immunorecative parathyroid hormone (iPTH) and indices of mineral and glucose metabolism were determined in 58 insulin treated diabetic patients (duration of disease 1–11 years). The mean serum iPTH level in all diabetic patients, measured simultaneously with sera from normal subjects, was 55% of normal mean (P < 0.01). The diabetic patients had hypomagnesaemia (P < 0.001), hypercalciuria (P < 0.001) and a 9.6% decrease in bone mass (P < 0.001). Low serum iPTH values were correlated with high glycosuria (R = −0.28, P < 0.05) and with long duration of diabetes (R = −0.31, P< 0.02). Patients with both high glycosuria and long diabetes duration had especially low iPTH values (mean 16 ng/l, n = 16) compared with patients with both low glycosuria and short diabetes duration (mean 32 ng/l, n = 15, P < 0.005) and with normal subjects (mean 37 ng/l, n = 28, P < 0.001). The 16 patients with low serum iPTH values also had higher urinary calcium excretion rate (P < 0.05) than the 15 patients with low glycosuria and short duration of diabetes. The diabetic hypoparathyroidism may be secondary to a primary disturbance of bone metabolism, with a negative net calcium balance.