Background
The relationship of lifestyle and socioeconomic factors with weight change over 4 years in Korean middle-aged group was assessed. Methods: A total of 1,167 men, aged 40∼59 years, were selected from the Health Promotion Center of Ulsan University Hospital during the period of Jan. 2000 through Mar. 2000. Including anthropometric measures, designed questionnaires were administered concern lifestyle behavior topics with cigarette smoking, exercise, alcohol consumption, dairy product consumption and socioeconomic factors of monthly income and education. The subjects were divided into three groups by body mass index (BMI: kg/m²); normal (＜23 kg/m²), overweight, and obesity (≥25 kg/m²). After 4 years of follow-up, the men were classified into weight change categories; 1) stable weight group (from normal to normal, from overweight to overweight) and 2) weight gain group (from normal to overweight/obesity, from overweight to obesity). Results: The weight gain group were 18.4% (n=215) and the stable overweight group were 81.6% (n=952). Adjusted for age, the frequency of dairy product consumption, the frequency of alcohol drinking, the regularity of exercise, education and monthly income, the smokers (≥10/day) had significantly high incidence rates of increase in weight (odds ratio=1.77, 95% CI 1.07∼2.90). The increased dairy consumers (≥4/week) had significantly low incidence rates of increase in weight (odds ratio=0.43, 95% CI 0.20∼0.93). Otherwise, there were no significant relationships in weight change. Conclusion: Smoking and decreased dairy product consumption were related to the increase in weight. (J Korean Acad Fam Med 2008;29:102-107)

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.