Associations of the ANKK1 and DRD2 gene polymorphisms with overweight, obesity and hedonic hunger among women from the Northwest of Iran.

Background: Pleasure from palatable foods can stimulate hedonic eating and, therefore, might be a major culprit for obesity. Dopamine receptor polymorphisms, especially variants in the genes regulating the D2 receptor, including ANKK1 and DRD2, are the prime candidates for assessing the individual differences in hedonic eating. This study was carried out to investigate the possible associations of the T (rs1800497) and Del (rs1799732) alleles with body mass index (BMI) and hedonic hunger among Iranian Azeri women.

Methods: A total of 372 healthy overweight/obese subjects (BMI ≥ 25 kg/m 2 ) and 159 normal weight individuals (BMI 18.5-24.9 kg/m 2 ) were genotyped for the polymorphisms of ANNK1 and DRD2 genes using PCR-RFLP. BMI and hedonic hunger were also evaluated.

Results: Three hundred and sixty-three (68.36%), 152 (28.63%), and 16 (3.01%) of the participants had CC, CT, and TT genotypes for ANNK1 gene, respectively. Of 515 samples genotyped for DRD2 gene, 315 (60.51%), 173 (33.59%), and 27 (5.24%) had Ins/Ins, Ins/Del, and Del/Del genotypes, respectively. The genotype and genotype frequencies were significantly different between the groups (p = 0.04). Significant differences were observed between the T+ genotype (TT + TC) and the T- genotype (CC) regarding the BMI and hedonic hunger scores (p < 0.05). In addition, Del+ group (Del/Del + Ins/Del) had higher BMI and hedonic hunger scores compared to Del- group (Ins/Ins) (p < 0.05).

Conclusions: Our findings showed that the frequencies of T and Del alleles were greater in the overweight/obese individuals. Also, the polymorphism of ANKK1 (rs1800497) and polymorphism of the DRD2 gene (rs1799732) showed significant associations with BMI and hedonic hunger.

Level of Evidence: Level III, case-control study.