The Relationship between Testosterone and Bone Mineral Density in Middle Aged Men

ABSTRACT

BACKGROUND: With the population aging, osteoporosis is becoming a major health issue. Although not as common as women, osteoporosis and its clinical end point of fracture are significant health care concern in men. Despite the considerable public health burden, our understanding of their pathogenesis is incomplete, and several factors known to affect bone metabolism in men are still controversial. So this study was made to investigate relationship between testosterone and bone mineral density in men. METHODS: This was a cross-sectional study of 432 men undertaken health screening program in Pundang CHA General Hospital from January 2000 to December 2000. We surveyed information concerning exercise and consumption of alcohol and smoking by means of self questionnaire records. Serum total testosterone, SHBG, and osteocalcin were measured at a fasting state. Second morning urine was tested for deoxypyridinoline. BMD was assessed using pQCT. RESULTS: FTI (free testosterone index) was positively correlated with BMD (r=0.265, P<0.01). Age, osteocalcin, SHBG, and urine deoxypridinoline were negatively correlated with BMD (r= 0.397, P<0.01, r= 0.121, P<0.05, r= 0.214, P<0.01, and r= 0.126, P<0.01). BMI and total testosterone had no significant correlation with BMD, and there were no apparent association among the level of alcohol and tobacco use, regular exercise and BMD. FTI was not independently correlated with BMD after age, BMI and urine deoxypyridinoline were adjusted, but showed a trend to significantly predict BMD (beta =0.10, P=0.052). CONCLUSION: These data suggest that FTI may play a role in determination of BMD in men, allowing the potential for clinical intervention. But further investigation of the role of testosterone in bone metabolism in men is necessary.