The Relationship among Testosterone, IGF- 1 and Fat Mass

Kim, Ki Young; Kang, In Sun; Kang, Young Gon; Kim, So Lim; Sin, Kyung Kyun; Kim, Moon Jong; Lee, Young Jin; Bae, Chul Young

Abstract

BACGROUND: 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 (gamma = 0.26; P <0.01, gamma = 0.15; P <0.05, gamma = 0.31; P <0.01). WHR was positively correlated with age (gamma =0.26; P <0.01) and negatively correlated with total testosterone, calculated free testosterone, and IGF-1 (gamma = 0.24; P <0.01, gamma = 0.20; P <0.01, gamma = 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 (beta = 0.072; P <0.01, beta = 0.0035; P <0.05) and WHR (beta = 6.9E-04; P <0.05, beta = 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.