The possible link between endocannabinoid system gene polymorphisms and overweight/obesity susceptibility in individuals living in the Marmara Region

Abstract Objectives Obesity is a global health problem related to reduced life quality and shorter life expectancy. Given the fact that genetic factors play a role in obesity development, studies have suggested that polymorphisms of cannabinoid receptor 1 ( CNR1 ), monoacylglycerol lipase ( MGLL ), and fatty acid amide hydrolase ( FAAH ) genes located in the endocannabinoid system (ECS) are related to overweight/obesity risk. Accordingly, we aimed to assess the genetic susceptibility to overweight/obesity in individuals with Turkish ancestral origin concerning these ECS genes. Methods The present study comprised 194 unrelated individuals with Turkish ancestral origin living in the Marmara Region. The study population is categorized into two groups according to their body mass index (BMI) overweight/obese group (BMI≥25) and normal weight group (18.5<BMI<25). Genotyping of the CNR1 rs1049353 , MGLL rs60430 , and FAAH rs324420 polymorphisms was performed using the real-time polymerase chain reaction (RT-PCR). Results The GG genotype frequency of CNR1 rs1049353 was significantly higher in overweight/obese individuals than in normal weight individuals (75.5 vs. 61.4 %, respectively; p=0.034). No difference was observed in terms of MGLL rs604300 and FAAH rs324420 polymorphisms between the groups (p>0.05). The genotype distributions of CNR1 , MGLL , and FAAH genes were compatible with the Hardy–Weinberg equilibrium (p>0.05). Conclusions Our findings supported that individuals with AA/AG genotype of CNR1 rs1049353 have reduced overweight/obesity risk; however, neither FAAH rs324420 nor MGLL rs604300 showed any association. A relatively smaller sample size and lack of inclusion of obesity-related measurements could be considered the limitations of this study. Further research is needed to confirm or disprove our results.