Serum osteopontin, but not OPN gene polymorphism, is associated with LVH in essential hypertensive patients

Abstract

This study aims to investigate the role of osteopontin (OPN) genetic polymorphisms in the occurrence of left ventricular hypertrophy (LVH) in Chinese patients with essential hypertension (EH). A total of 1,092 patients diagnosed with EH were recruited. Three single nucleotide polymorphisms (SNP) on the promoter region of the OPN gene, including -66T/G, -156G/GG, and -443C/T were genotyped. The serum thrombin-cleaved OPN levels were studied. Patients were divided into LVH+ (n = 443) and the LVH- (n = 649) groups. We found that none of the studied SNPs in the OPN gene was associated with the risk and severity of LVH. The SNPs in the OPN gene did not correlate with the serum OPN levels. However, the serum thrombin-cleaved OPN levels were found to be an independent risk factor for LVH in the EH patients. Multivariate logistic regression analysis showed that serum thrombin-cleaved OPN levels were independently associated with the development of LVH (adjusted OR = 2.47, 95% CI 1.56-4.01, adjusted P < 0.001). In vitro studies showed that the thrombin-cleaved OPN treatment increased the protein content per cell, the cardiomyocyte surface size, and the expression level of atrial natriuretic peptide protein in a dose-dependent manner. The thrombin-cleaved OPN serum level, but not OPN gene polymorphism, is associated with the development of LVH in EH patients. Serum OPN is related to LVH incidence in essential hypertension subjects. OPN stimulates cardiomyocyte hypertrophy in vitro. OPN SNPs are not related to LVH incidence.