No association between rs7566605 variant and being overweight in Japanese.

It has recently been demonstrated that a common single-nucleotide polymorphism (rs7566605) upstream of the transcription start site for the insulin-induced gene 2 is associated with obesity in several European/European origin or African-American cohorts. We tested whether this variant is also linked to overweight among Asian populations. Our sample included 2233 randomly selected, community-dwelling, middle-age and older Japanese people (men, 1128; women, 1105; age, 40 to 79 years; C allele frequency, 0.32). We observed that there were no differences in BMI levels [men, 22.9 +/- 0.3 (mean +/- standard error) vs. 22.9 +/- 0.1, p = 0.820; women, 22.8 +/- 0.3 vs. 22.9 +/- 0.1, p = 0.792], waist circumferences and hip circumferences, waist-to-hip ratio, and fat mass between rs7566605 GG/GC and CC genotypes in both genders. In addition, logistic regression analysis, using age and sex as covariates, revealed no association of the single-nucleotide polymorphism with overweight (BMI >or=25) between rs7566605 genotypes in the Japanese cohort (CC vs. CG/GG, odds ratio = 1.18; 95% confidence interval = 0.84 to 1.65, p = 0.333; CC vs. GG, odds ratio = 1.19, 95% confidence interval = 0.84 to 1.69, p = 0.325). No significant associations were observed between polymorphism and glucose or insulin levels. These results suggested no association of the rs7566605 variant with overweight in Japanese people.