Abstract

 Introduction: Lipid level variations are among the most important risk factors for cardiovascular disease. Apolipoproteins play a the key role in lipid metabolism. In the present study the association of XbaI apolipoprotein B polymorphisms on lipid variation was examined. Materials and Methods: A cross-sectional study was conducted on 849 subjects from the Tehran Lipid and Glucose Study population. Blood pressure was measured and the body mass index was calculated. TG, Chol, FBS, HDL-C and its subfractions, Apo B and Apo A1 levels were measured, and LDL-C concentration was calculated. A segment of the apo B gene was amplified by PCR and the polymorphism was revealed by RFLP using XbaI restriction enzyme. Results: Allele frequencies obtained for X+ and X- were 27.6 % and 72.4%, respectively and were in the Hardy-Weinberg Equilibrium (HWE). The presence of the X+ allele was significantly associated with increased total cholesterol (X+X+: 193 ± 1.2 mg/ml vs. X-X-: 182 ± 1.2 mg/ml, P 0.022) and apolipoprotein B (X+X+: 116 ± 1.5 mg/ml vs. X-X-: 104 ± 1.4 mg/ml, P 0.024). The associations were significant even after adjustment for age, sex, BMI, smoking, diastolic and systolic blood pressure and fasting blood sugar. Conclusion: The observed allele frequencies were similar to other studies. Considering the association of XbaI polymorphisms with lipids factors, it is important to examine the relationship of Apo B gene variation and similar gene with lipids metabolisms.