ENPP1 K121Q Genotype Not Associated with Coronary Artery Calcification in Korean Patients with Type 2 Diabetes Mellitus

BACKGROUND Ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) generates inorganic pyrophosphate, a solute that serves as an essential physiological inhibitor of calcification. Inactivating mutations of ENPP1 are associated with generalized calcification in infancy and an increased risk of developing type 2 diabetes mellitus (T2DM). We hypothesized that the ENPP1 K121Q variant may be associated with increased coronary artery calcification in T2DM patients. METHODS The study subjects were aged 34 to 85 years and showed no evidence of clinical cardiovascular disease prior to recruitment. A total of 140 patients with T2DM were assessed for their coronary artery calcium (CAC) scores and ENPP1 K121Q polymorphisms were identified. RESULTS The prevalence of subjects carrying the KQ genotype was 12.9% (n = 18). There were no 121QQ homozygotes. Patients with the KQ genotype did not show a significantly higher CAC score (122 vs. 18; P = 0.858). We matched each patient with the KQ genotype to a respective control with the KK genotype by gender, age, and duration of diabetes. When compared to matched controls, we observed no significant difference in CAC score (P = 0.959). CONCLUSIONS The ENPP1 K121Q polymorphism does not appear to be associated with coronary artery calcification in patients with T2DM.