Independent association of FTO rs9939609 polymorphism with overweight and obesity in Polish adults. Results from the representative population-based WOBASZ study

Genetic factors play an important role in the origin of obesity. We investigated the association between the FTO rs9939609 genotype and overweight and obesity, along with additional anthropometric variables in the representative sample of adult Polish population. We genotyped a random sample of 3369 adult individuals examined in a cross-sectional population survey (WOBASZ 2003-2005). More than 40% of men and women had at least one A allele. The AA genotype was found in approximately one fifth of both men and women. The frequency of the AA genotype increased with higher BMI in both sexes and was associated with higher anthropometric obesity indicators in both men and women. The FTO rs9939609 AA genotype was significantly related to abnormal BMI [OR=1.55 (1.14-2.11)] and overweight [OR=1.55 (1.11-2.16)] or obesity [OR=1.56 (1.04-235)] in men regardless of age, tobacco smoking, physical activity, diet and diabetes, while in women it was related to abnormal BMI [OR=1.45 (1.05-2.01)] and overweight [OR=1.59 (1.11-2.29)] after adjustment in addition for menopause. The frequency of the A allele in the Polish population was the same as in other European countries. About one fifth of both men and women have the FTO rs9939609 AA variant. A significant relationship was found between the FTO genotype and anthropometric obesity indicators. The AA genotype was significantly associated with abnormal BMI and overweight in both sexes, but the relation to the obesity phenotype was observed only in men.