Association of rs9939609 of the FTO Gene with Obesity Phenotypes in Women

Aim. To study the association of rs9939609 of the FTO gene with various obesity phenotypes, its individual parameters, and some risk factors in a sample of women

Design. Cross-sectional cohort study.

Materials and methods. The study was conducted on the basis of the population sample of the HAPIEE project, the age of the participants was — 45–69 years (n = 1036). Groups of women were formed, selected by body mass index (BMI) using the criteria of the World Health Organization. DNA was isolated from blood using the phenol-chloroform extraction method. Genotyping of the rs9939609 gene FTO was performed using polymerase chain reaction (PCR) with restriction fragment length polymorphism and real-time PCR (TaqMan probes). The frequency of genotypes in groups with different BMI, with different body roundness indexes (BRI), waist and hip circumference; with morbid obesity (MO) and abdominal obesity (AO) was analyzed.

Results. When comparing the frequencies of the A allele (AA and AT genotypes) and the TT genotype in groups with different BMIs, significant differences were obtained (p = 0.007). The highest frequency of the TT genotype (38.5%) was in the group of women with a BMI of 18.5 to 24.9 kg/m², the  lowest (23.5%) — with a BMI of 35 to 39.9 kg/m². In this group, the AA genotype was most common. The frequency of carriage of the AT genotype increased nonlinearly with increasing BMI. The statistical significance of differences in BMI between carriers of different genotypes according to the Kruskal — Wallis — test is less than 0.001. Significant differences were also observed in waist (p = 0.001) and hip (p < 0.001) circumferences — the smallest in carriers of the TT genotype. In univariate logistic regression analysis with age-adjusted adjustment, the odds ratio (OR) of having MO in the AA genotype — 1.80 (95% confidence interval (CI): 1.09–2.95; p = 0.021), in the AT genotype — 1.82 (95% CI: 1.23–2.68; p = 0.002), and in the TT genotype — 0.56 (95% CI: 0.39–0.81; p = 0.002). In the univariate logistic regression analysis with age-adjusted analysis, the significance of the TT genotype carriage as a conditionally protective factor in relation to the development of MO (OR = 0.56; 95% CI: 0.34–0.91; p = 0.021) and AO (OR = 0.65; 95% CI: 0.45–0.94; p = 0.023) was preserved, as was the increased probability of AO in carriers of the AT genotype (OR = 1.53; 95% CI: 1.15–2.02; p = 0.003) and AA genotype (OR = 1.54; 95% CI: 1.06–2.23; p = 0.023).

Conclusion. Carriage of the A allele of rs9939609 of the FTO gene is an important factor associated with various obesity phenotypes in women. Due to the diversity of factors associated with obesity, it is necessary to continue research in this area to develop effective personalized preventive and therapeutic strategies.

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