Gene variations of nitric oxide synthase regulate the effects of a saturated fat rich meal on endothelial function

Abstract

Background & aims: Endothelial nitric oxide synthase (eNOS) gene variations have been linked to a higher risk for cardiovascular diseases (CVD) by unknown mechanisms. Our aim was to determine if two single nucleotide polymorphisms (SNPs) located in NOS3 (E298D and i19342) interfere with microvascular endothelial function (MEF) and/or oxidative stress during the postprandial state.

Methods: MEF was assessed with laser Doppler flowmetry at baseline and 2, 4, 6 and 8 h after ingestion of a single fatty meal (60% fat, 15% proteins and 25% carbohydrates) by 40 healthy young males. Oxidative stress was measured by nitrites/nitrates and oxidized LDL (LDL-ox) concentrations in fasting and postprandial states.

Results: Postprandial MEF was impaired in the carriers of minor alleles of the SNPs (global mean 60.99% Vs 87.25%, p = 0.016 for i19342; 63.62% Vs 95.71%, p = 0.011 for E298D). Carriers of E298D showed a higher LDL-ox at fasting and postprandial measures, and lower nitrites/nitrates at fasting.

Conclusions: Minor allele carriers for E298D and i19342 have an impaired postprandial MEF and increased oxidative stress. Our results both provide insight into the higher risk of CVD attributed to E298D and identify variants that affect MEF in a healthy population.