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 rs17782313 polymorphisms with obesity measures and metabolic parameters in urban and rural dwelling Sri Lankans. Methods: 535 subjects (60.9% female) from the general adult population (ages 18-70 years) representative of both urban (28.4%) and rural areas of residence were recruited by multi-stage random sampling. Body mass index (BMI), waist circumference (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(-2) definition) (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(-2) definition) (OR 1.57 95% CI 1.11-2.22, p = 0.01). In addition the MC4R risk 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 genotypes compared to rural living (p = 0.02). Conclusions: FTO and near MC4R variants are associated with obesity measures in Sri Lankan populations whilst urban living accentuates the obesogenic effect of the FTO polymorphism. (C) 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.