Background Osteoporosis (OP) is a growing health problem not only in women but also in men. It is well known that men lose bone during ageing and are at risk for OP, but the risk factors for OP in men remains controversial.

Objectives The aim of this study was to assess determinants of bone mineral density (BMD) at the lumbar spine and femoral neck in healthy males.

Methods Thirty-seven healthy men aged 43–73 years were included in this study. BMD was measured using dual photon absorptiometry. Predictors of lumbar spine and femoral neck BMD were determined using multiple linear regression analysis. Backward elimination procedure was used to identify variables significantly related to BMD. The independent variables entered the regression model included age, body mass index (BMI), smoking history, alcohol intake, urinary calcium and hydroxyproline, and serum concentrations of osteocalcin, parathyroid hormone, testosterone, growth hormone, and cortisol.

Results The mean age of the men was 59.8 ± 6.8 years. Mean BMD at the lumbar spine was 0.97 ± 0.10 gr/cm² and that of the femoral neck was 0.76 ± 0.06 gr/cm². Backward elimination procedure was used to identify variables significantly related to BMD. The independent variables entered the regression model included age, body mass index (BMI), smoking history, alcohol intake, urinary calcium and hydroxyproline, and serum concentrations of osteocalcin, parathyroid hormone, testosterone, growth hormone, and cortisol. Backward regression analysis indicated that testosterone, cortisol and BMI were significant predictors of BMD at the lumbar spine (R = 0.44, p < 0.05) while testosterone, hydroxyproline and osteocalcin were significant predictors of BMD at the femoral neck (R = 0.20, p < 0.05). Testosterone, cortisol and BMI accounted for 44% of the total variance in lumbar spine BMD, and testosterone, hydroxyproline and osteocalcin accounted for 20% of the total variance in femoral neck BMD. Men with lower BMI had significantly lower bone mass at the lumbar spine (r = 0.43, p < 0.05). In addition, men with lower bone mass at the lumbar spine had significantly higher serum cortisol levels (r = -0.33, p < 0.05).

Conclusion These observations suggest that testosterone, cortisol and BMI are main determinants of lumbar spine BMD, while testosterone, urinary hydroxyproline and osteocalcin are main determinants of femoral BMD in our group of healthy men.