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.