Association between Interleukin-1B C-31T polymorphism and obesity in Japanese.
BACKGROUND
Recent studies have revealed a close relationship between obesity and polymorphism in the inflammation gene. However, the association between interleukin-1beta (IL-1beta) and obesity remains controversial. We therefore investigated the association between IL-1B C-31T polymorphism and obesity in Japanese.


METHODS
The participants were 802 inhabitants (281 men and 521 women) of Japan, aged 39 to 88 years, who attended a health examination in 2003. Body height, weight, waist and hip circumferences, and body fat percentage were measured. The IL-1B C-31T polymorphism was genotyped by polymerase chain reaction with confronting 2-pair primers. The association between IL-1B C-31T genotypes and various indices of obesity was then investigated. The confounding factor-adjusted odds ratios (OR) and 95% confidence intervals (CI) for obesity were calculated for each IL-1B C-31T genotype by using unconditional logistic regression analysis.


RESULTS
Among male carriers of the CT and TT genotypes, the ORs for high body fat percentage were 2.58 (95% CI, 1.17-6.34) and 2.81 (1.17-7.33), respectively, as compared to carriers of the CC genotype (P for trend = 0.037). Among women, carriers of the TT genotype had significantly higher ORs for high BMI (OR, 2.13; 95% CI, 1.25-3.67) and large waist circumference (2.49; 1.37-4.66), as compared to women with the CC genotype (P for trend = 0.005 and 0.004, respectively).


CONCLUSIONS
The IL-1B C-31T polymorphism is associated with obesity in Japanese. Men and women with the TT genotype of IL-1B C-31T had a higher risk for obesity than those with the CC genotype.
Suzuki
Koji
K
Department of Public Health, School of Health Sciences, Fujita Health University, Toyoake, Aichi, Japan. ksuzuki@fujita-hu.ac.jp
Inoue
Takashi
T
Yanagisawa
Atsumi
A
Kimura
Asami
A
Ito
Yoshinori
Y
Hamajima
Nobuyuki
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001837:Body Weights and Measures; D005260:Female; D005838:Genotype; D015438:Health Behavior; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000208:ethnology / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
D053583:Interleukin-1beta