Association of the Aldosterone Synthase Gene -344T>C Polymorphism with Essential Hypertension and Glucose Homeostasis: a Case-control Study in a Han Chinese Population

1. Aldosterone is a hormone that affects both blood pressure and glucose homeostasis. We studied the association of the aldosterone synthase gene (CYP11B2) polymorphism -344T>C with essential hypertension (EH) and glucose homeostasis in people in China. 2. We investigated the polymorphism -344T>C in CYP11B2 using a case-control study design (1059 cases and 1120 controls). Genotyping was carried out by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy using a MassARRAY platform. 3. The aldosterone synthase gene -344T>C polymorphism was found to be associated with EH (odds ratio 1.252; 95% confidence interval 1.067-1.468; P(add) = 0.006). The -344C variant was found to be significantly associated with increased systolic blood pressure (P(add) = 0.003) and diastolic blood pressure (P(add) = 0.024) in controls and increased plasma aldosterone levels (P(add) = 0.0001) in EH cases. The -344C variant was also found to be significantly associated with increased fasting glucose (P(rec) = 0.003) in controls. In the subgroup containing 893 EH cases without a history of diabetes or hypoglycaemia medications, the -344C variant was found to be associated with increased fasting and postprandial plasma glucose levels (P(add) = 0.0001, P(add) = 0.001, respectively) and decreased pancreatic β-cell function and insulin sensitivity (P(add) = 0.030, P(dom) = 0.019, respectively) by homeostasis model assessments. 4. In this Han Chinese population, the -344T/C polymorphism of the CYP11B2 gene was found to be associated with EH and glucose homeostasis, both of which might be mediated by plasma aldosterone levels, insulin sensitivity and β-cell function.