Osteoporosis in juvenile-onset diabetes mellitus: morphometric and comparative studies.

Ribs and vertebrae of 8 children and young adults aged from 17 months to 24 years with juvenile-onset diabetes mellitus, 4 with diabetes secondary to cystic fibrosis and 2 with diabetes secondary to thalassemia major, were analyzed for osteoporosis by a point-count morphometric method. The mean ratio of bone spicule to marrow space in cancellous bone of ribs of patients with juvenile-onset diabetes mellitus or with diabetes mellitus secondary to cystic fibrosis or thalassemia was 55% that of 10 control patients. The lengths of the zones of proliferating and mature cartilage cells in costal epiphyses of patients with juvenile-onset diabetes mellitus were also below normal. The ratio of bone spicule to marrow space of vertebrae of the diabetic patients was not significantly different from control values. The data confirm clinical reports that osteoporosis is a regular feature of juvenile-onset diabetes mellitus and suggest that the degree of bone matrix and mineral deficiency in such patients is greater than is usually considered.