Background: Liver X receptor Beta (LXRβ), located in an obesity susceptible region, has been shown to be involved in the metabolism of lipid and carbohydrates. Previous human genetic studies have suggested genetic variability of LXRβ could be associated with human obesity. Therefore, we hypothesized that LXRβ gene rs2695121 polymorphism may be associated with the risk of obesity in a northeastern Iranian population.
Methods: A TaqMan allelic discrimination assay was used to genotype LXRβ rs2695121 polymorphism in this cross-sectional study of 168 obese, 209 overweight and 76 normal-weight subjects recruited from Mashhad city in Iran. Logistic regression analyses were used to analyze alleles and genotypes distribution. Anthropometrics and clinical variables among different genotype carriers were compared by univariate analyses. All statistical analysis was performed using SPSS v.16.0.
Results: Allelic and genotypic associations with obesity were not significant for the rs2695121 variant even after adjustment for age and gender (OR=1.17, 95% CI=0.46-2.91), p=0.586). Moreover, haplotype analysis using data from the other variant (rs17373080) of LXRβ revealed no significant association (p=0.88). However, among the clinical and metabolic parameters tested, systolic and diastolic blood pressures were found nominally associated with the genotype CT (p=0.031 and p=0.017 respectively).
Conclusion: This study failed to demonstrate any association between the rs2695121 variant of LXRβ and obesity neither alone nor when considered with rs17373080. However, its association with blood pressure may influence one's susceptibility to obesity, supporting further studies in a larger population.
Keywords: Liver X receptor-β; Obesity; Polymorphism; rs2695121.