Background
: Bone mass changes in men is related to age, BMI, sex hormones and other factors. In prior studies, bone markers were negatively correlated with bone mineral density, free testosterone, and estrogen and was positively correlated with SHBG. In a study of sex hormones and bone markers in Korean men estradiol was negatively correlated with deoxypyridinoline. In this study, the relationship of testosterone, estradiol, calculated free testosterone, FEI and SHBG to bone turnover markers in adult men were investigated.

Methods : This was a cross-sectional study of 184 men who had undertaken a health screening program in one general hospital in Bundang from November, 2001 to February, 2003. We surveyed information concerning the past medical history, current medication, alcohol consumption amount per week and smoking amount by means of self questionnaire records. Serum total testosterone, estradiol, SHBG and osteocalcin, alkaline phosphatase were measured at a fasting state. Urine was tested for deoxypyridinoline. Free testosterone was calculated using albumin, SHBG, and total testosterone level.

Results : Deoxypyridinoline adjusted by age, BMI was negatively correlated with FEI (r=-0.17, P=0.020) and was positively correlated with smoking amount (r=0.20 P= 0.007). Osteocalcin was negatively correlated with calculated free testosterone and ethanol consumption amount (r=-0.186, P=.0.12, r=-0.186, P=0.012). Multiple regression analysis showed that the most powerful factor influencing deoxypyridinoline was smoking amount (R²= 0.046), followed by FEI, BMI, and the one influencing osteocalcin was BMI (R²=0.050), ethanol amount and calculated free testosterone. After adjusting for age, BMI, drinking amount and smoking amount FEI shown to be a predictor of deoxypyridinoline (β=-0.08, p＜0.01, R²=0.101). After adjusting for age, BMI, and drinking amount calculated free testosterone was shown to be a predictor of osteocalcin (β=-0.570, P＜0.01, R²=0.130) in multiple regression model.

Conclusion : In adult men, FEI shown to be a predictor of deoxypyridinoline and calculated free testosterone to be a predictor of osteocalcin as an independent variable.

Background
: The age-related increase in fat mass seems related to decrease in hormone level. Few studies have been done in Korea concerning the association between testosterone, GH (growth hormone) and fat mass. This study was undertaken to evaluate the relationship among testosterone, IGF-1 and fat mass.

Methods : The study was performed from February to October 2001 in the Health Screening Center of Pundang CHA Hospital with 243 men as subjects. Fat intake was measured through interview with diet therapist and other data were obtained by self-questionnaire. Fat mass was measured using Inbody 3.0 and the level of total testosterone, SHBG and IGF-1 in serum were measured.

Results : Smoking was negatively correlated with fat mass and WHR (waist to hip ratio) (P＜0.05) and fat intake was positively correlated with fat mass (P＜0.05). Fat mass was negatively correlated with total testosterone, calculated free testosterone, and SHBG (r=-0.26; P＜0.01, r=-0.15; P＜0.05, r=-0.31; P＜0.01). WHR was positively correlated with age (r=0.26; P＜0.01) and negatively correlated with total testosterone, calculated free testosterone, and IGF-1 (r=-0.24; P＜0.01, r=-0.20; P＜0.01, r=-0.16; P＜0.05). After adjustment for age, body mass index, smoking, and fat intake, the calculated free testosterone and IGF-1 were independently negatively correlated with fat mass (β=-0.072; P＜0.01, β=-0.0035; P＜0.05) and WHR (β=-6.9E-04; P＜0.05, β=-4.0E-05; P＜0.05) but, total testosterone and SHBG were not independently correlated with fat mass and WHR.

Conclusion : The results indicate that the calculated free testosterone and IGF-1 can be independent determinants of fat mass and WHR in middle-aged men.