Obezitede FTO Gen Varyantlarının Diyet Bileşenleri ile İlişkileri

Abstract

The interactions of FTO gene variants with diet and other lifestyle habits on obesity indicators have attracted attention in recent years. Evidences from studies conducted in different populations are important for understanding this relationship. In this study, it was aimed to investigate in detail the interactions of FTO gene variants (rs9939609 and rs10163409) with both dietary nutrient content and diet quality on obesity in Turkish population. A total of 400 participants including 200 healthy controls (Body Mass Index (BMI): 18.5-24.9 kg/m2), and 200 pre-obese/obese patients (BMI≥25 kg/m2), whose physical examinations were carried out in Hacettepe University Adult Hospital, were included in the study. The mean age of the individuals participating in the study was 34.8 ± 7.08 years. The socio-demographic characteristics, smoking and alcohol use, physical activity levels, sleep quality and eating habits of the individuals were questioned, and a 24-hour dietary recall was used retrospectively. Healthy Eating Index-2010 (HEI-2010) and Mediterranean Diet Adherence Scale were used to determine the diet quality. FTO gene polymorphisms were performed using Competitive Allele Specific PCR genotyping. Fasting and postprandial blood samples were taken from individuals and serum lipid profile, fasting plasma glucose and insulin, postprandial glucose and insulin, plasma adiponectin, and 25-dihydroxy vitamin D levels were evaluated. Additionally, the HOMA-IR value was calculated and systolic and diastolic blood pressures were measured. FTO rs9939609 minor allele (A) frequency was 39%, and FTO rs10163409 minor allele (T) frequency was 37%. FTO rs9939609 A allele carriers were obese at 19.5% and TT genotype 9.4% (p=0.028). The obesity percentage for FTO rs10163409 was similar across genotypes (p=0.768). It was found that the total number of meals in all genotypes for the FTO rs9939609 genotype, and in the AA genotype for the FTO rs10163409 was negatively correlated with general obesity, and the number of snacks was negatively correlated with markers of abdominal obesity indicators (p<0.05 for each). Dietary carbohydrate intake was found to be positively correlated with the obesity markers for the rs9939609 TT genotype, and negatively correlated with body fat percentage for AA/AT. Dietary fat intake was positively correlated with body fat percentage in individuals with AA genotype (p<0.05). In terms of FTO rs10163409 gene variants, dietary protein intake was associated with an increase in body fat percentage in individuals with the TA/TT genotype. Energy percantage from fat was associated with the increased body fat percentage in the AA genotype, while it had a negative relationship with abdominal obesity indicators in TA/TT genotype (p<0.05 for each) for the same SNP. It was determined that in individuals with a total risk allele number of 1 and above, the risk of high waist-to-hip ratio decreased by 35% as n-3 fatty acid intake increased (p=0.033). As the individuals’ diet quality, with FTO rs9939609 TT genotype, increased, plasma fasting insulin, postprandial insulin and HOMA-IR levels decreased (p<0.05 for each). In the FTO rs10163409 AA genotype, the plasma adiponectin level increased when the diet quality score increased, while the plasma fasting insulin level and HOMA-IR values decreased (each p<0.05). The interaction of FTO rs9939609 genotype and physical activity level affected the plasma adiponectin level (p=0.027). Plasma adiponectin level was lower in sedentary individuals with risk allele compared to those without risk allele (p=0.006). As a result, it has been confirmed that FTO gene variants might affect the response to obesity indicators, by modifying the dietary and other lifestyle habits in obesity in an adult Turkish sample.