Association between senescence‐related uncoupling protein 2 gene polymorphisms and abdominal obesity in Japanese subjects: The Tanno and Sobetsu study

Abstract

Background: Uncoupling protein 2 (UCP2) plays an important role in regulating body weight, energy expenditure and insulin secretion. UCP2 is upregulated in white fat in response to fat feeding, and negatively controls insulin secretion. UCP2 also has a function that protects cells from apoptosis and oxidative stress, which shows UCP2 might be a senescence‐related gene. Previously, UCP2‐866G/A polymorphism in the promoter region has been reported to alter adipose tissue mRNA expression and is associated with obesity in Caucasians.Methods: In this study, we investigated the association between this polymorphism and obesity, insulin secretion and hypertension in the general Japanese population.Results: The allele frequency of UCP2‐866G/A polymorphism was significantly higher in Japanese subjects compared to Caucasians. It revealed that subjects only in the obese group with the AA type of UCP2‐866G/A polymorphism had significantly higher levels of body mass index (BMI) and waist circumference. Multiple logistic regression analysis showed that this polymorphism was independently associated with waist circumference. This positive association remained in the analysis of the subgroup younger than 65 years, but not in the older group. This polymorphism did not affect levels of insulin and homeostasis model assessment ratio (HOMA‐R).Conclusions: These results suggest that the AA type of UCP2‐866G/A polymorphism is related to abdominal obesity, which indicates the possible role of this polymorphism in causing metabolic syndromes.