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

Obes Res Clin Pract. 2016 Sep:10 Suppl 1:S117-S124. doi: 10.1016/j.orcp.2016.02.003. Epub 2016 Mar 3.

Abstract

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 ≥27.5kgm-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 ≥25kgm-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.

Keywords: FTO; MC4R; Obesity; Single nucleotide polymorphism; Sri Lankan.

MeSH terms

  • Adult
  • Alleles
  • Alpha-Ketoglutarate-Dependent Dioxygenase FTO / genetics*
  • Asian People / genetics*
  • Blood Glucose / metabolism
  • Body Mass Index
  • Female
  • Gene-Environment Interaction*
  • Genetic Predisposition to Disease
  • Genotype*
  • Humans
  • Male
  • Middle Aged
  • Obesity / etiology*
  • Obesity / genetics
  • Obesity, Abdominal / etiology
  • Obesity, Abdominal / genetics
  • Odds Ratio
  • Polymorphism, Single Nucleotide*
  • Receptor, Melanocortin, Type 4 / genetics*
  • Residence Characteristics
  • Rural Population
  • Sri Lanka
  • Urban Population
  • Waist Circumference

Substances

  • Blood Glucose
  • Receptor, Melanocortin, Type 4
  • Alpha-Ketoglutarate-Dependent Dioxygenase FTO
  • FTO protein, human