Significant associations of abdominal obesity with LYPLAL1 polymorphism (rs4846567) among a general Japanese population: a cross-sectional study

Tamura, Takashi

Significant associations of abdominal obesity with LYPLAL1 polymorphism (rs4846567) among a general Japanese population: a cross-sectional study

Tuesday, 19 August 2014

Exhibit hall (Dena'ina Center)

Takashi Tamura, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Emi Morita, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Sayo Kawai, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Tae Sasakabe , Nagoya University Graduate School of Medicine, Nagoya, Japan

Nana Fukuda, MS , Nagoya University Graduate School of Medicine, Nagoya, Japan

Yuka Sugimoto, MS , Nagoya University Graduate School of Medicine, Nagoya, Japan

Shino Suma , Nagoya University Graduate School of Medicine, Nagoya, Japan

Junichiro Mokuno, MD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Hiroko Nakagawa, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Asahi Hishida, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Rieko Okada, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Mariko Naito, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Nobuyuki Hamajima, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

Kenji Wakai, PhD , Nagoya University Graduate School of Medicine, Nagoya, Japan

INTRODUCTION: Obesity is one of the most important health concerns in the world. To date, a lot of studies including genome wide association studies (GWAS) have reported that single nucleotide polymorphisms (SNPs) were clearly associated with obesity. Among them, lysophospholipase-like-1 (LYPLAL1, rs4846567) is reported to be associated with female-biased waist circumference (WC). We therefore investigated whether this SNP is associated with WC, and confirmed an interaction with sex.

METHODS: Study subjects were 5,131 participants aged 35-69 years (1,458 males and 3,673 females) in the Daiko Study, a part of the Japan Multi-Institutional Collaborative Cohort Study (J-MICC Study). WC was classified into two groups, < or ≥85 cm (in male) and < or ≥90 cm (in female), respectively, based on the criteria of international diabetes federation (IDF) 2005 for Japanese.

RESULTS: Genotype frequencies of LYPLAL1 (rs4846567) were 39.9% for GG, 46.2% for GT and 13.9% for TT, and were in Hardy-Weinberg equilibrium (p=0.513). The allele frequencies were 0.630 for G and 0.370 for T. The multivariate-adjusted OR and 95% confidence interval (CI) for high WC was 1.63 (95% CI: 1.03-2.58) for those with TT relative to those with G allele in men, while the OR was 0.67 (95% CI: 0.41-1.10) in women. The crude means ± standard deviation (SD) of WC were significantly different between genotypes as a whole (p=0.02), and the interaction with sex was also highly significant (p<0.001). The means ± SD in men were 83.4 ± 8.4 for GG, 84.5 ± 8.3 for GT and 85.3 ± 9.2 for TT, while those in women were 78.0 ± 8.7 for GG, 78.6 ± 9.0 for GT and 77.9 ± 8.5 for TT.

CONCLUSIONS: Our study showed that LYPLAL1 (rs4846567) was significantly associated with female-biased waist circumference in a general Japanese population. Stratified analyses including other LYPLAL1 SNPs related with obesity were required.