Dietary total antioxidant capacity interacts with a variant of chromosome 5q13-14 locus to influence cardio-metabolic risk factors among obese adults

Background The association between cocaine- and amphetamine-regulated transcript prepropeptide gene (CARTPT) and obesity-related outcomes has shown in the epidemiological studies. Nevertheless, there is lack of data regarding the CARTPT gene-diet interactions in terms of antioxidant potential of diet. So, this study aimed to test CARTPT gene-dietary non-enzymatic antioxidant capacity (NEAC) interactions on cardio-metabolic risk factors in obese individuals. Methods and material The present cross-sectional study was carried out among 288 apparently healthy obese adults within age range of 20-50 years. Antioxidant capacity of diet was estimated by calculating the oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), total radical-trapping antioxidant parameter (TRAP) and Trolox equivalent antioxidant capacity (TEAC) using a semiquantitative food frequency questionnaire (FFQ). Genotyping for CARTPT rs2239670 polymorphism was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results A significant interaction was revealed between CARTPT rs2239670 and dietary ORAC on BMI (P-Interaction = 0.048) and fat mass percent (FM%) (P-Interaction = 0.008); in A allele carriers, higher adherence to the dietary ORAC was related to lower level of BMI and FM%. And, the significant interactions were observed between FRAP index and rs2239670 in relation to HOMA (P-Interaction = 0.049) and QUICKI (P-Interaction = 0.048). Moreover, there were significant interactions of rs2239670 with TRAP (P-Interaction = 0.029) and TEAC (P-Interaction = 0.034) on the serum glucose level; individuals with AG genotype were more respondent to higher intake of TRAP. Conclusion The present study indicated that the relationships between CARTPT rs2239670 and obesity and its-related metabolic parameters depend on adherence to the dietary NEAC. Large prospective studies are needed to confirm our findings.