O 08. Association of serum testosterone levels and metabolic syndrome in Chinese residents in Taiwan

The metabolic syndrome (MetS) has drawn world-wide attention due to its association with an increased risk of cardiovascular disease. Low serum testosterone (TT) is considered to be a risk factor of MetS in men.

In 2008, a study was conducted among Chinese residents in Taiwan, China, with subjects older than 40 years recruited through media. Anthropometric characteristics including blood pressure, height, body weight and waist circumference were measured. Biochemical measurements including TT, hormonebinding globulin (SHBG), albumin, fasting blood sugar (FBS), triglyceride (TG), cholesterol (CHO), were determined by blood sampling. Based on the recommendation of The International Society for the Study of the Aging Male (ISSAM), a total T below 320 ng/dL (11 nmole/L) or a free T below 6.6 ng/dL (0.225 nmole/L) is considered as low value. The MetS is diagnosed by the Modified Asian AHA/NHLBI criteria.

Among 1062 participants, 857 men were eligible for data analysis. Men with MetS were increased in higher age, and low TT and calculated free T (C. FT) were increased as age increased. When the participants with MetS were analyzed separately from the non-MetS within each age group, low TT was positively correlated to MetS in age group of 40's rather than other ages. The subjects with low TT in the age group of 40's had higher prevalence of MetS than in other age groups.

Low TT and low C. FT were increased in higher age, and men with MetS were increased odds with low TT. Particularly in age group of 40's, the correlation of low TT with MetS was tighter (O.R.=8.2) than in other age groups (total O.R.=4.0). Thus, low TT may provide an early warning sign of developing MetS for the middle-aged Chinese residents in Taiwan, China.