The Mitochondrial DNA Variant 16189T>C Is Associated with Coronary Artery Disease and Myocardial Infarction in Saudi Arabs

Abstract

By virtue of the functional role of the mitochondrion in energy and reactive oxygen species production, mutations in mitochondrial DNA (mtDNA) are potential candidates for cardiovascular-related disorders. Further, the mtDNA is extremely polymorphic and several diagnostic single-nucleotide polymorphisms have been used to assort sequences into haplogroups with defined continental and regional ranges. However, the relevance of these haplogroups and mutations with respect to coronary artery disease (CAD) susceptibility remains unclear. In this study, we evaluated the role of the 16189T>C variants and mtDNA haplogroups as predisposing factors for CAD in 669 Saudi patients with angiographically established disease compared with 258 disease-free controls. The 16189T>C was associated with CAD (1.524 [1.076-2.159]; p = 0.017). However, this association was influenced by age as well as the presence of myocardial infarction and hypertension. Among the haplogroups, only the N1c showed a borderline protective relationship (p = 0.074) with CAD as an independent risk factor. This association turned significant in the total sample (0.176 [0.042-0.736]; p = 0.017) and in the <50-year age group (0.075 [0.008-0.743]; p = 0.027), when included as a possible confounding factor. Our results suggested that the impact of mtDNA polymorphism on CAD manifestation is influenced by important confounders, particularly the presence of myocardial infarction, hypertension, and age.