Studies of single nucleotide polymorphism (SNP) of angiotensin-converting enzyme (ACE) gene and serum ACE protein level in association with hypertension in Thai patient

Abstract

Hypertension is a strong risk factor for stroke and cardiovascular disease. It is a complex disease resulting from the interactions of environmental factors and genetic factors, especially those genes that affect the regulation of blood pressure. The renin–angiotensin system (RAS) may play a crucial role in the regulation of blood pressure and pathogenesis of hypertension. Angiotensin converting enzyme (ACE) has a central role in this system by producing the angiotensin II and the degradation of bradykinin resulting in vasoconstriction. This study aimed to investigate serum ACE protein levels and SNP, rs4343, in ACE gene in association with risk of hypertension in Thai population. A total of 30 hypertension patients (SBP>140 mmHg, DBP>90 mmHg) and 30 controls (SBP<120 mmHg, DBP<80 mmHg) were recruited. Serum lipids were examined by using enzymatic colorimetric and homogeneous methods. Serum ACE levels were examined by ELISA kit. The SNP, rs4343 (exon 17), in ACE gene was genotyped by polymerase chain reaction (PCR) and high-resolution melting (HRM) analysis. The data were analysed using t-test and chi-square test of SPSS program version 16.0. The results showed that the triglyceride level in the hypertension group was significant higher than the control (p=0.004). But there was no significant differences in the level of cholesterol, HDL and LDL. The ACE levels showed significant difference between patient (192.19±104.33 ng/ml) and control (146.37±46.65 ng/ml) groups (p=0.02). However, there is no significant differences in genotype distribution of SNP, rs4343, in ACE gene in the subjects with and without hypertension (p=0.629). The data from this study suggested that there is a relationship between ACE protein levels and hypertension, but no association of SNP, rs4343, in ACE gene with risk of hypertension in Thai patient.