Investigation of MAO-A, COMT, VMAT2, DAT1 gene polymorphisms among overweight and obese adults in turkish population

Obesity is a health problem which is increasingly becoming prevalent in the worldwide and risky for several diseases. Due to the multifactorial, the prevention and treatment of obesity is so difficult. The idea that obesity is a neurobiological disease rather than a metabolic disorder, is the basis of our hypothesis. Changes in dopamine neurotransmission affect the brain reward system in a direct way. Furthermore, changes in the reward system influence the eating behavior in human. DAT1 and VMAT2 transporter proteins terminate DA function by moving into presynaptic neurons and vesicles, and MAOA and COMT enzymes terminate the function by metabolizing DA. In our study, the control group which includes 214 individuals and obese group that involve 234 subjects were investigated for MAOA-u VNTR, 3' UTR DAT1 VNTR, COMT (rs4680), DAT1 (rs27072), VMAT2 (rs363399), VMAT2 (rs4752045) polymorphisms. There is no study which clarifies the association between DAT1 (rs27072), VMAT2 (rs363399), VMAT2 (rs4752045) polymorphisms and obesity in the literature. In our study, statistical analysis has showed that in control group Val/Met COMT genotype is significantly higher according to obese group (p=0.04). When obese and control groups are compared, it has been observed that DAT1 A/A genotype is dramatically higher in patient group (p=0.018). When the groups were compared in terms of eating behavior, the number of the subjects who ate for reward was significantly higher in obese group (p=0.03). Our findings demonstrate that eating behavior may affect the development of obesity and the dopaminergic gene polymorphisms could be a risk factor for the pathogenesis of obesity in adults in Turkish population.