Identification par l’analyse des facteurs cliniques de risque et la densitométrie osseuse des hommes à risque d’ostéoporose

Abstract

Male osteoporosis is often secondary to other conditions. However the causes of osteoporosis in men are dramatically variable according to the authors. The aim of this observational multicenter study was to assess the main risk factors and causes for male patients with low bone mineral density (LBM). The study was performed in a cohort of rheumatologists who usually prescribe bone mineral density assessment according to HAS criteria (one or more criteria) for bone mineral density (BMD) measurement as defined by: (a): vertebral fracture; (b): non traumatic non vertebral fracture; (c): corticosteroid therapy; (d): hypogonadism or GnRH agonist therapy; (e): endocrine disorders; (f): osteogenesis imperfecta (OI). BMD was measured by dual photon absorptiometry (DXA) at lumbar spine, femoral or total neck sites. Osteoporosis was defined as a T-score value less or equal to 2.5 at one of those region of interest (ROI); LBM as a T-score value between -1 and -2.5. A total of 431 rheumatologists included 1198 male patients (66.6 ± 12.2 years). According to DXA results, 888 patients (74.1 %) had osteoporosis and 231 (19.3 %) had osteopenia. BMD was considered as normal for 79 patients (6.6 %). A total of 1146 patients (95.7 %) satisfied to the criteria of reimbursement of DXA measurement. Six hundred and eighty-six patients (57.3 %) had suffered from vertebral fractures and 349 patients (29.2 %) from non vertebral fractures. Corticosteroids had been prescribed in 28.7 % of patients and 6.6 % were treated with GnRH agonists for prostate cancer. Hypogonadism was diagnosed in 27 %. Five patients suffered from OI. Other risk factors were detected: alcoholism and smoking in 28.1 % and 42.9 % respectively; rheumatoid arthritis or spondylarthropathy in 12.5 % of patients; chronic pulmonary disorders in 16.1 %. By contrast endocrinopathies were rare (2.5 %). Several risk factors were more frequently encountered for patients with osteoporosis as compared with osteopenia, i.e., smoking, alcohol abuse, low calcium intake, vitamin D insufficiency and maternal history of hip fracture. A diagnosis of osteoporosis (BMD ≤ 2.5) was established by rheumatologists in 74.1 % of patients with clinical risk factors: LBM was found in 93.4 %. In 95.7 % the criteria for reimbursement of DXA measurement were satisfied. DXA is useful in male patients with classical risk factors of osteoporosis to confirm the diagnosis of the disease and start a treatment.