The association between SIRT1 gene and children obesity:Seoul-Kuro Cohort Study

Abstract

Sirtuin 1(SIRT1) is a longevity gene that protects cells against oxidative and genotoxic stress. But recent study suggests that SNPs of the SIRT1 gene was associated with body fat, BMI, and visceral obesity. However the association of SIRT1 polymorphism with childhood obesity is not reported. The purpose of this study is to investigate association of SIRT1(rs7895833) gene and anthropometrics, lipid profile, insulin resistance related profile, and nutrient intake in 3 years of follow-up study(between 2007 and 2010). The original study population consisted of 491(boy: 246, girl: 245) third grade elementary school student and followed up 219(boy: 101, girl: 118) after 3 years. The genotyping was performed using a polymerase chain reaction(PCR) with confronting 2-pair primers(CTPP). During 3 years, anthropometric parameters were increase but biochemical and nutrient intake were decrease both boy and girl. The distribution of obesity children was increase during 3 years. The 88% of children who had normal BMI of 2007 were also normal in 2010, and the 85% of children who had obesity of 2007 were also obesity in 2010. Also, the children of normal in 2007 were changed obese children in 2010 were 15%. The frequencies of SIRT1 genotype were GG homozygotes(wild) 57.1%, AA homozygotes(mutant) 4.1%, and GA heterozygotes(hetero) 38.8%. Higher frequency of variant GA+AA in SIRT1 rs7895833 observed significantly in obese girl group than in normal girl group(38.7% vs 64.0%, P<0.05). Although energy, protein, fat, and cholesterol intake were decreased in children having GA+AA genotype, the increment of BMI and WC was higher than them with GG. Also, the decrements of TC and LDL in GA+AA were lower than the children having GG. And Obesity children with GG genotype having a negative correlation between mean change of CHO intake and mean change of TG concentration. Also mean change of HOMA-IR was same result with TG. In conclusion, the SIRT1 polymorphism was found to be associated with obesity. And the children having GG genotype of SIRT1 rs7895833 showed protective effects of TG and HOMA-IR in Korean obesity children during 3 years.