The association between the GNB3 rs5443 C/C genotype and obesity phenotypes in Taiwanese individuals

Background: The prevalence of obesity has increased significantly over the years, and its health concerns cannot be underestimated. Obesity not only causes potential mobility limitations in daily life but also increases the risk of developing cardiovascular diseases, diabetes, cancer and other health conditions. While an imbalanced diet and lack of exercise are well-known causes of obesity, genetic patterns also influence its development. Although the GNB3 gene is known to be involved in lipid metabolism and fat cell differentiation, studies have shown inconsistent associations between a common single nucleotide polymorphism of GNB3 (c.825C>T, rs5443) and obesity across different populations. Therefore, this study aims to analyze the association between the GNB3 c.825C>T polymorphism and obesity in the Taiwanese population using various grouping criteria. Subjects/Methods: The study recruited 372 eligible subjects for GNB3 SNP rs5443 (c.825C>T) testing at China Medical University Hospital in Taichung, Taiwan. Clinical parameters, including age, sex, weight, BMI and body fat percentage were assessed for all participants. The GNB3 rs5443 C/T genotypes were determined using two differentially labeled allele-specific probes and a specific paired PCR primer set. Results: Our results demonstrated that the distribution of GNB3 rs5443 genotypes (C/C, C/T, T/T) was not significantly correlated with sex and age (p > 0.05). However, the distribution of GNB3 genotypes (C/C, T/T) showed a statistical significance between subjects with BMI < 24 and BMI  27. Furthermore, our results revealed that the C/T and T/T genotypes had higher frequency distributions compared to the C/C genotype in females with body fat percentages below 30% (p = 0.022 and p = 0.004, respectively). Conclusions: Taiwanese individuals carrying the C/C homozygous genotype of the GNB3 gene may have a higher susceptibility to obesity, particularly among females. This finding could potentially be combined with polymorphisms of other obesity-related genes to develop a clinical screening tool for assessing obesity risk.