Association of FTO polymorphisms with obesity and obesity-related outcomes in Portuguese children.

Abstract

BackgroundSeveral studies have reported an association between single nucleotide polymorphisms in the first intron of the FTO gene and body mass index (BMI) or obesity. However, this association has not yet been studied among the Portuguese population. This study aims to assess the association of three FTO polymorphisms (rs1861868, rs1421085 and rs9939609) with obesity-related outcomes in a sample of Portuguese children.MethodsWe examined a total of 730 children, 256 normal-weight (55.9% girls), 320 overweight (45.3% girls) and 154 obese (53.2% girls), aging from 6 to 12-years-old, recruited randomly from public schools in the central region of Portugal. DNA samples were genotyped for the three polymorphisms by allelic discrimination TaqMan assay. Association of the FTO polymorphisms with several anthropometric traits was investigated. Additionally, we tested association with the risk of obesity using overweight and obese vs. normal-weight children.ResultsWe found significant associations of rs9939609 and rs1421085 polymorphisms with weight, BMI, BMI Z-score, waist circumference and hip circumference, even after age and gender adjustment (p0.05). Haplotype analyses identified two combinations (ACA and GCA) associated with a higher risk of obesity (OR 1.53; 95% CI, 1.06-2.22; p = 0.023; OR 1.73; 95% CI, 1.06-2.87; p = 0.030, respectively).ConclusionsThis study provides the first evidence for the association of FTO polymorphisms with anthropometric traits and risk of obesity in Portuguese children.