PCSK9 E670G Polymorphism and Its Clinical Implications in Obese Elderly Patients Undergoing Bariatric Surgery ^†

Introduction: The PCSK9 gene encodes the NARC-1 protein, a key regulator of cholesterol metabolism. Its overexpression reduces LDL receptor availability, increasing plasma LDL-C levels. The E670G polymorphism (23968A>G) enhances LDL receptor degradation, contributing to hypercholesterolemia and increased risk of atherosclerosis and coronary artery disease. This variant is also associated with obesity due to its influence on lipid metabolism, particularly in individuals with insulin resistance and dyslipidemia. The objective of this study was to evaluate the association between the E670G polymorphism and clinical, metabolic, and inflammatory parameters in obese elderly individuals undergoing bariatric surgery. Methodology: Twenty-seven patients aged 60 years or older were genotyped for the PCSK9 E670G variant. Clinical data were collected, including lipid profile, glycemia, insulin levels, thyroid function, and cytokines (ethics committee approval #1,910,166). Statistical analysis was performed using Pearson’s chi-square and Mann–Whitney U tests, with significance set at p < 0.05. Results: The results showed no significant differences between AA and AG genotype groups in most parameters, except for calcium supplementation, which was more prevalent in the AG group (p = 0.027). Conclusions: These findings suggest that, under the conditions studied, the PCSK9 E670G polymorphism does not significantly influence metabolic or inflammatory profiles in obese elderly individuals. A significant limitation of this study is the small sample size, which may reduce statistical power and limit the generalizability of the findings. Further longitudinal research is needed to clarify the role of PCSK9 in cardiometabolic risk among aging populations.