Human AGT-p.Met268Thr and coronary heart disease risk: a case-control study and meta-analysis

Background
Polymorphisms in genes, which is involved in the renin–angiotensin system, play an important role in the pathogenesis of coronary heart disease (CHD). Polymorphism of c.803T>C in the human angiotensinogen gene results in methionine (M) to threonine (T) substitution at codon 268 (p.Met268Thr), which traditionally has been known as M235T. This polymorphism may contribute to cardiovascular diseases.

Objectives
The aim of this study was to investigate the association between p.Met268Thr polymorphism in the angiotensinogen gene and coronary heart disease (CHD) through a case-control study, which is followed by a meta-analysis.

Material and methods
In the case-control study, c.803T>C genotyping of 217 subjects (102 CHD cases vs 115 controls) was investigated by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. In the meta-analysis, 31 studies were included, reflecting 12,028 people with CHD and 16,362 healthy controls.

Results
The data from the case-control study revealed that MT (OR, 1.875; 95%CI, 1.060–3.316; p = 0.031) and TT (OR, 3.389; 95%CI, 1.251–9.179; p = 0.016) genotypes are significantly associated with CHD. The meta-analysis revealed a significant association in the recessive model (OR, 1.156; 95%CI, 1.011–1.321; p = 0.034).

Conclusions
Although the pooled OR of the meta-analysis showed that there is an increased risk of CHD conferred by p.Met268Thr of the AGT gene, this association was weak, which could be attributed to a bias in publications.