Alterations of bone and mineral metabolism in diabetes mellitus. Part II. Clinical studies in 206 patients with type I diabetes mellitus.

This study reports a 22% prevalence of significant cortical osteopenia in 206 patients, aged 7-20 years, with established insulin-dependent diabetes mellitus (IDDM). A parallel decrease in trabecular bone mass was also noted. Bone loss was more evident in males (16%) than in females (6%) and was rare before 10 years of age (3%). No relationship between bone loss and the duration of diabetes, degree of metabolic control or diabetic complications was apparent. Delayed skeletal maturation did not account for cortical thinning, and the mean bone age of osteopenic diabetics was similar to that of non-osteopenic diabetics. There was no significant correlation between HLA-antigen frequency and the predisposition to diabetic osteopenia. Metabolic alterations comparable with previous findings in the chronically diabetic rat were documented in IDDM. The data documented are consistent with the conclusion that IDDM results in intestinal hyperabsorption of calcium, absorptive hypercalciuria, phosphaturia, hypomagnesaemia, hyperphosphatasaemia, and decreased circulating parathyroid hormone levels. These alterations in mineral metabolism may relate to the decrease in cortical and trabecular bone mass observed in patients with IDDM.