Low serum testosterone level as a predictor of increased visceral fat in Japanese-American men.
OBJECTIVE
To examine the association between baseline testosterone levels and changes in visceral adiposity in Japanese-American men.


METHODS
Prospective observational study.


METHODS
Second-generation Japanese-American males enrolled in a community-based population study.


METHODS
At baseline, 110 men received a 75g oral glucose tolerance test (OGTT), and an assessment of body mass index (BMI); visceral adiposity measured as intra-abdominal fat area (IAF) using computed tomography (CT); fasting insulin and C-peptide levels; and total testosterone levels. IAF was re-measured after 7.5 y. Subcutaneous fat areas were also measured by CT in the abdomen, thorax and thigh. The total fat (TF) was calculated as the sum of IAF and total subcutaneous fat areas (SCF).


RESULTS
After 7.5y, IAF increased by a mean of 8.0 cm2 (95% CI: 0.8, 15.3). Baseline total testosterone was significantly correlated with change in IAF (r= -0.26, P= 0.006), but not to any appreciable degree with change in BMI, TF, or SCF. In a linear regression model with change in IAF as the dependent variable, baseline testosterone was significantly related to this outcome while adjusting for baseline IAF, SCF, BMI, age, diabetes mellitus status (OGTT by the WHO diagnostic criteria) and fasting C-peptide (regression coefficient for baseline testosterone [nmol/l] = -107.13, P = 0.003).


CONCLUSIONS
In this Japanese-American male cohort, lower baseline total testosterone independently predicts an increase in IAF. This would suggest that by predisposing to an increase in visceral adiposity, low levels of testosterone may increase the risk of type 2 diabetes mellitus.
Tsai
E C
EC
Department of Medicine, University of Washington, Seattle, USA.
Boyko
E J
EJ
Leonetti
D L
DL
Fujimoto
W Y
WY
D000005:Abdomen; D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000378:metabolism*; D000368:Aged; D001786:Blood Glucose; D001823:Body Composition; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D015331:Cohort Studies; D006801:Humans; D007328:Insulin / Q000097:blood; D007564:Japan / Q000208:ethnology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000208:ethnology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013739:Testosterone / Q000097:blood*; D014057:Tomography, X-Ray Computed; D014861:Washington / Q000453:epidemiology
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D013739:Testosterone