The mitochondrial DNA variant 16189T>C is associated with coronary artery disease and myocardial infarction in Saudi Arabs.

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.

Lack of association of lipoprotein lipase gene polymorphisms with coronary artery disease in the Saudi Arab population.

CONTEXT: Previous studies reported an association of certain polymorphisms in the lipoprotein lipase (LPL) gene with the risk of coronary artery disease (CAD); however, these studies were small and inconsistent. In addition, none of these studies attempted to establish such an association in the Arab population. OBJECTIVE: To determine whether 2 LPL polymorphisms (LPL-HindIII and LPL-PvuII located on introns 8 and 6, respectively, of the LPL gene) can be considered as independent risk factors or as predictors for CAD in Arabs. DESIGN: We used polymerase chain reaction and restriction enzyme digestion to determine the distribution of the LPL-HindIII and LPL-PvuII polymorphisms among healthy blood donors of Arabic origin (BD group) and angiographically confirmed CAD patients (CAD group) with identical ethnic backgrounds. RESULTS: For the HindIII genotypes, within the BD group (n = 410), the +/+ genotype was found in 206 individuals (50.2%), 173 (42.2%) carried the +/- genotype, and 31 (7.6%) carried the -/- genotype. Within the CAD group (n = 352), the +/+ genotype was found in 189 individuals (53.7%), 138 (39.2%) carried the +/- genotype, and 25 (7.1%) carried the -/- genotype. P values of.38,.45, and.92 were obtained for the +/+, +/-, and -/- genotypes, respectively. For the PvuII genotypes, within the BD group (n = 511), the +/+ genotype was found in 182 individuals (35.6%), 248 (48.5%) carried the +/- genotype, and 81 (15.9%) carried the -/- genotype. Within the CAD group (n = 431), the +/+ genotype was found in 138 individuals (32%), 225 (52.2%) carried the +/- genotype, and 68 (15.8%) carried the -/- genotype. P values of.28,.29, and.98 were obtained for the +/+, +/-, and -/- genotypes, respectively. The distribution and the allele frequency of these 2 LPL variants were similar in CAD and BD study groups and followed the Hardy-Weinberg equilibrium. CONCLUSION: There was no difference in the distribution of both LPL polymorphisms between the healthy group and the CAD group. Therefore, these 2 LPL polymorphisms cannot be considered as independent risk factors or as predictors for CAD in this population.