The association between Cocaine- and Amphetamine- Regulated Transcript (CART) gene polymorphism with feeding behavior, basal metabolic rate (BMR) and lipid profile in obese adult individuals

Abstract

Abstract Objective: Cocaine- and Amphetamine-Regulated Transcript Prepropeptide (CARTPT) gene is a hypothalamic anorectic neuropeptide that controls feeding behavior and body weight. The aim of this study was to evaluate association between feeding behavior, basal metabolic rate and lipid profile with Cocaine- and Amphetamine-Regulated Transcript Prepropeptide CARTPT gene rs2239670 variant among apparently healthy obese Iranians. Methods: 188 apparently healthy individuals with a body mass index (BMI) of 30-40 kg/m2 and aged 20-50 years were enrolled in this cross-sectional study. Samples were collected by convenience sampling through advertising in the public places of the Tabriz in west-north of Iran. Anthropometric characteristics [weight, height, BMI, waist circumference (WC), hip circumference (HC) and waist-to-hip ratio (WHR)] and lipid profile levels were measured in all subjects. For assessing the feeding behavior of participants, the Three-Factor Eating Questionnaire Reduced (TFEQ-R18) was used. The CARTPT gene rs2239670 polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) technique. Data were analyzed by Chi-square and ANOVA tests. In all statistical analyses, a P value of less than 0.05 was considered statistically significant. Results: The results showed that the majority of the participants had GG genotype (65.4%) and minor allele frequency for this polymorphism was 20.8%. There were no significant differences between three factor structure of TFEQ [cognitive restraint (CR), emotional eating (EE) and uncontrolled eating (UE)], basal metabolic rate and lipid profile levels with CARTPT polymorphism rs2239670 (P > 0.05). There was a significant interaction between CARTPT rs2239670 and dietary intake on WC, SBP and BMI after adjustment for confounding variables. In A allele carriers (high-risk allele), higher intake of carbohydrate was related to higher level of WC (Pinteraction = 0.047). Also, homozygotes individuals for high-risk alleles (AA genotypes) had the highest level of SBP and BMI at higher tertiles of fat intake (Pinteraction = 0.015 and Pinteraction = 0.029, respectively). Conclusions: The CARTPT rs2239670 polymorphism seems not to be associated with feeding behavior, basal metabolic rate and lipid profile among this study population. But dietary intake of macronutrients can also moderate the association of this polymorphism with some anthropometric parameters and blood pressure. Keywords: feeding behavior, basal metabolic rate, lipid profile, CARTPT, polymorphism