RESUMO
BACKGROUND: Controversial data is available on the effect of the Melanocortin-4 receptor (MC4R) gene variation on metabolic syndrome (MetS) and ineffectiveness of diet in managing MetS. Effects of the interaction between MC4R polymorphism and dietary factors on MetS were investigated in this study. METHODS: Subjects of this nested case-control study were selected from among participants of Tehran Lipid and Glucose Study. Each case (n = 815) was pair matched randomly with a control by age (±5 years) and sex from among those who had not developed ≥1 MetS components at the time that the corresponding case developed MetS. Dietary patterns were determined using factor analysis on 25 foods groups using a valid and reliable, 168-item semi-quantitative food frequency questionnaire (FFQ). MC4R rs12970134 were genotyped by Tetra-Primer ARMS-polymerase chain reaction analysis. Adjusted conditional logistic regression was used to estimate the interactions of SNP with quartiles of dietary factors in relation to MetS. MetS was defined by the modified National Cholesterol Education Program/Adult Treatment panel III. RESULTS: Two dietary patterns were extracted. The healthy dietary pattern was loaded heavily on vegetables, legumes, low fat dairy, whole grains, liquid oils and fruits; the western dietary pattern consisted of a high intake of soft drinks, fast foods, sweets, solid oils, red meats, salty snacks, refined grains, high fat dairy, tea and coffee, eggs and poultry. Among A allele carriers, being in the highest quartiles of western dietary pattern score and saturated fatty acid intake had an increased risk of MetS, compared to those in the lowest quartile (P trend = 0.007). Saturated fatty acid intake could modulate the association of A allele carriers of MC4R with MetS (P interaction = 0.03). A significant interaction was observed between rs12970134 with total fat and iron intake on the risk of abdominal obesity (P interaction < 0.05). CONCLUSION: Our findings suggest an interaction between rs12970134 and western dietary pattern, fat and vegetable intakes on the risk of MetS or its components.
RESUMO
INTRODUCTION: Metabolic syndrome (MetS) is a multi-factorial disorder with five important components. A high triglyceride level combined with low HDL cholesterol has been reported to be associated with Apolipoprotein A5 (APOA5) gene variations. In this study, we aimed to determine the association of single nucleotide polymorphisms including: rs662799, rs3135506 and rs2075291 in the apolipoprotein A-V (APOA5) gene in relation to MetS component like triglyceride and HDL-C level in Tehran Lipid and Glucose Study (TLGS). MATERIALS AND METHODS: Metabolic syndrome was defined according to ATPIII and phenotypes were defined by the National Cholesterol Education Program (NCEP) criteria for MetS. Demographic, biochemical parameters and anthropometric variables were measured. Selected APOA5 gene polymorphisms were genotyped using PCR-RFLP method. RESULTS: From TLGS population, 947 adults, aged 19 - 70 years, were randomly selected and recruited into the study. Mean age, triglyceride and WC were higher and mean HDL was lower in MetS vs. non-MetS group. C allele in rs2075291 showed a significant association with MetS (OR: 2.38, 95% CI; 1.11 - 5.08, P = 1.5 ×10(-2)). The association was shown between higher serum triglyceride and the presence of T allele (P = 4.5 × 10(-4)) and also lower serum HDL-C and the presence of T allele (P = 1.6 × 10(-3)) in rs2075291. Also this association showed between raised waist circumference and C allele in rs3135506 (P = 3.5 × 10(-2) ) and raised systolic and diastolic blood pressure level and C allele of rs662799 (P = 4.5 × 10(-2)). CONCLUSION: According to the results, there is a relationship between lipid profile and studied polymorphism in the presence of metabolic syndrome. It seems that APOA5 rs2075291 could play an important role in triglyceride and HDL-C level in metabolic syndrome affected, while the association of APOA5 rs662799 polymorphism is still under debate.
