Chemical and histological features of men with osteoporosis.

Six men (average age, 42) underwent evaluation for idiopathic osteoporosis. Standard measurements of serum and urine were studied. Lumbar skeletal mineral density was measured by dual-photon absorptiometry. Skeletal biopsies of the iliac crest were obtained after double-labeling with tetracycline. Average renal cyclic adenosine monophosphate and urinary calcium values were elevated. Lumbar spinal density was 72% of age-matched norms, and histomorphometric analyses of bone revealed decreased trabecular bone volume and formation rate and increased trabecular osteoid area, osteoclast number, and calcification rate. The results suggest that idiopathic osteoporosis in these men is associated with increased parathyroid hormone secretion as assessed by increased renal cyclic adenosine monophosphate and high skeletal remodeling activity.