ENPP1 K121Q Functional Variant Enhances Susceptibility to Insulin Resistance and Dyslipidemia with Metabolic Syndrome in Asian Indians

Background: Ectonucleotide pyrophosphatase/phosphodiesterase1 (ENPP1/PC-1) is a key modulator of the insulin signaling pathway, and its common variant, K121Q, increases the susceptibility to diabetes and cardiovascular diseases. Objectives: The main objective of the present study was to investigate the association of ENPP1 K121Q polymorphism with the pathophysiology of metabolic syndrome (MetS) in a north Indian population. Methods: A total of 567 participants (303 MetS subjects and 264 healthy controls) were examined for ENPP1 genotypes and various clinical parameters, including body mass index (BMI), waist circumference (WC), systolic and diastolic blood pressures (SBP/DBP), fasting blood glucose (FBG), cholesterol, triglycerides (TG), high-density lipoprotein, and insulin. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Statistical analysis of the data was done using SPSS. Results: Significant increases in BMI, WC, SBP, DBP, FBG, TG, low-density lipoprotein, insulin, and Homeostasis Model Assessment of insulin resistance (HOMA-IR) and of beta-cell function (HOMA-BF) were observed in MetS patients compared to healthy controls. Logistic regression analysis of data demonstrated a nonsignificant association of QQ and KQ+QQ genotypes with increased risk of MetS (OR [95% CI], 1.583 [0.455–5.507], p = 0.470 for QQ genotypes and 1.097 [0.784–1.540], p = 0.587 for KQ+QQ genotypes). Moreover, MetS subjects carrying Q alleles had significantly higher levels of TG, insulin, body fat percentage, and insulin resistance as evident by higher values of HOMA-IR. Conclusions: We conclude that ENPP1 K121Q functional variant enhances susceptibility to insulin resistance and dyslipidemia in MetS subjects of an Asian Indian population.