Association of FTO and near MC4R variants with obesity measures in urban and rural dwelling Sri Lankans

Objectives: To investigate the association between the fat mass and obesity related(FTO) gene rs9939609 and near melanocortin-4-receptor (MC4R) gene rs17782313polymorphisms with obesity measures and metabolic parameters in urban and ruraldwelling Sri Lankans.Methods: 535 subjects (60.9% female) from the general adult population (ages18—70 years) representative of both urban (28.4%) and rural areas of residencewere recruited by multi-stage random sampling. Body mass index (BMI), waist cir-cumference (WC) and waist-to-hip ratio (WHR) was obtained by standard methods.DNA extracted from whole blood was genotyped using real-time PCR.Results: The FTO risk genotypes (AA + AT) were associated with higher BMI (p = 0.03)and WC (p = 0.05) measures as well as categorical obesity (BMI ≥27.5 kg m−2defini-tion) (OR 1.69 95% CI 1.11—2.56, p = 0.01). The near MC4R risk genotypes (CC + CT)were associated with greater BMI (p = 0.03) as well as categorical obesity (BMI≥25 kg m−2definition) (OR 1.57 95% CI 1.11—2.22, p = 0.01). In addition the MC4Rrisk genotype carriers (CC + CT) had significantly higher fasting blood sugar (FBS)levels compared to the ‘TT’ genotype carriers independent of BMI (p = 0.05). Urban living was associated with significantly greater BMI values for FTO risk genotypescompared to rural living (p = 0.02).Conclusions: FTO and near MC4R variants are associated with obesity measures in SriLankan populations whilst urban living accentuates the obesogenic effect of the FTOpolymorphism.