Association of beta2-adrenergic receptor and insulin receptor substrate-1 polymorphisms with obesity in a Northern Indian population

BACKGROUND: Imbalance in hormonal levels, regulated by host genetic factors, are known to be a major cause of obesity. Therefore, we aimed to evaluate association of genetic polymorphisms of beta(2)-adrenergic receptor (beta(2)-AR) and insulin receptor substrate-1 (IRS-1) with hormonal levels in northern Indian obese.

METHODS: A total of 111 obese and 89 age matched non-obese subjects were studied after taking detailed clinical profile. Hormonal assays in serum/plasma for different hormones were done using IRMA and RIA kits. Genetic analysis of beta(2)-AR (-47 and -20, T to C) and IRS-1 (Arg972Gly) was done using PCR-RFLP.

STATISTICAL ANALYSIS: Statistical analysis was performed by SPSS (version 11.5) software. All continuous variables were expressed as mean +/- SD and tested by ANOVA test. Comparisons of categorical variables were assessed using X(2) tests or Fisher's exact test. P-value <0.05 was considered as significant.

RESULTS: Analysis showed that obese subjects had significantly higher value of blood pressure (systolic), WHR, leptin insulin and glucagon and lower value of GH. In beta(2)-AR (-47) T/C and IRS-1 Gly972Arg gene polymorphisms we did not found significant differences in genotype or allele frequencies. Moreover, none of the studied hormonal or metabolic parameters showed any association with the gene polymorphisms.

CONCLUSIONS: Study reveals no significant association of beta(2)-AR (-47 and -20, T to C) and IRS-1 Gly 972 Arg polymorphisms with obesity in northern Indians.