Introduction: Although the etiology of osteoporosis is different between men and women, the underlying pathophysiologic mechanism is similar, namely an absolute or relative increase in bone resorption, leading to progressive bone loss. Transforming growth factor (TGF) beta-1 is a growth factor in human bone, which is produced by osteoblasts and inhibits osteoclast proliferation and activity and stimulates proliferation and differentiation of preosteoblasts.
The aim of our study was to determine serum TGF beta-1 levels in male patients with idiopathic osteoporosis.
Methods: Twenty five male with idiopathic osteoporosis and 25 age-matched controls were studied. Osteoporosis was defined by a T score <−2.5 in the lumbar spine or at the femoral neck. Exclusion criteria were known atherosclerotic disease, diabetes, morbid obesity, familial hyperlipidemias and severe systemic diseases. The patients, who had any secondary cause of osteoporosis or other metabolic bone diseases, were not enrolled in the study. We measured levels of TGF beta-1, estradiol and bioactive testosterone. Various markers of bone remodeling were also measured.
Results: TGF beta-1 was significantly lower in the osteoporotic patients than in controls (4.6±3.08 vs 8.97±4.4; P=0.000). Moreover, TGF beta levels were negatively correlated with bone mineral density (BMD) at the lumbar spine (r=−0.41, P=0.042) and at the femoral neck (r=−0.44, P=0.028). No correlation was found between serum estradiol, bioactive testosterone and TGF beta-1 levels.
Discussion: Our study suggests that TGF beta may play a key role in male patients with idiopathic osteoporosis. Serum TGF beta-1 levels are decreased in osteoporotic men and negatively correlated with hip and spine BMD. Serum TGF beta-1 levels appears to have potential as a marker for osteoporosis.