Aetiology and clinical characteristics of male osteoporosis. Have they changed in the last few years?

OBJECTIVE: The aim of this study was to analyse the clinical characteristics and etiological factors related to male osteoporosis in patients attending an out-patient rheumatology department during an 11-year period (1995-2006), as well as to compare them with the observed characteristics in a previous study performed 12 years ago.
METHODS: 232 males aged 21-88 (mean 56.1+/-14) with osteoporosis were included in the study. Previous skeletal fractures and family history of osteoporosis were recorded. Bone mass assessment, automated biochemical profile and hormonal measurements (including PTH, 25-OH vitamin D, cortisol, thyroid and sexual hormones) were performed on most patients as well as 24 h urinary calcium, and bone markers. In patients with idiopathic osteoporosis 1-25-OH2 vitamin D was also determined. In addition, x-rays of the spine were obtained for all patients.
RESULTS: 67% of the patients had previous skeletal fractures and 51% had vertebral fractures. 57% of the patients had idiopathic and 43% had secondary osteoporosis whereas in the previous series only 22% of the patients had idiopathic disease. The most frequent causes of secondary osteoporosis were corticosteroid therapy, hypogonodism and alcoholism. 38% of the patients with idiopathic osteoporosis had associated hypercalciuria. Patients with secondary osteoporosis were older, shorter, had lower femoral neck T-score and lower serum values of 25-OH vitamin D and testosterone, as well as higher gonadotrophin and PTH values than the patients with idiopathic osteoporosis, whereas patients with idiopathic osteoporosis had higher urinary calcium and more frequent family history of osteoporosis. Hypercalciuric patients were younger, had lower lumbar BMD, higher urinary calcium and greater incidence of lithiasis than normocalciuric patients with idiopathic osteoporosis. Back pain, frequently associated with vertebral fractures, was the most common cause of referral in all groups of patients.
CONCLUSION: Idiopathic osteoporosis is the most frequent cause of male osteoporosis in this study. In these patients, family history of osteoporosis and associated hypercalciuria are frequent. The most frequent causes of secondary osteoporosis in males include corticosteroid therapy, hypogonadism and alcoholism. Although clinical characteristics of male osteoporosis are similar to that previously reported, in this study the percentage of patients with idiopathic osteoporosis was higher than previously observed.