Variants of endothelial nitric oxide synthase gene are associated with components of metabolic syndrome in an Arab population
K. Alkharfy1, N. Al-Daghri1, O. Al-Attas1, M. Alokail1, A. Mohammed1, B. Vinodson1, M. Clerici2, U. Kazmi1, T. Hussain1 & H. Draz1,3
Genetics plays a crucial role in the development of metabolic syndrome (MetS). Here we examined the association between endothelial nitric oxide synthase (eNOS) gene polymorphisms and MetS in a Saudi Arabian cohort to extend the understanding of the genetic basis of MetS in diverse ethnic populations. Anthropometric, clinical and biochemical parameters as well as genotyping for 894G>T, −786T>C variants of eNOS gene by PCRRFLP and 4a/b by direct PCR were performed in 886 Saudi Arabians (477 MetS and 409 Non-MetS). The genotype distribution (TT, P=0.001; TC, P=0.001; TC+CC, P=0.001) and allele (T, P=0.007; C, P=0.007) frequency of the −786T>C SNP were significantly different between Non-MetS and MetS subjects which remained significant after Bonferroni correction. Moreover: i) the GT and GT+TT genotypes of the 894G>T SNP were associated with elevated blood pressure (P=0.017, and P=0.022 respectively); ii) the ab variant of 4a/b polymorphism was associated with decreased HDL levels (P=0.044); and iii) the TC+CC genotype and C allele of the −786T>C SNP were associated with increased fasting glucose levels (P=0.039, and P=0.028 respectively). Also, G-a-C was identified as the risk haplotype for MetS susceptibility (P=0.034). The result suggest a significant association of 894G>T, 4a/b and −786T>C polymorphisms with MetS and its components is present in an Arab population. A genetic predisposition to develop abnormal metabolic phenotypes, consistent with an increased prevalence of metabolic phenotypes can be detected in this ethnic group.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.