MIR-199A-5P is a marker of blood pressure in premature cardiovascular disease patients homozygous for the MTHFR C677T polymorphism

Background: microRNAs are small, non‐coding RNAs which are potentially valuable markers of cardiovascular disease (CVD) risk, including hypertension. This novel investigation aims to profile circulating serum concentrations of microRNAs in premature CVD patients to identify microRNAs that correlate best with hypertension. Methods: Serum samples from an existing cohort of 75 premature CVD patients were analysed for expression of 68 CVD‐related microRNAs. Patients had been screened for the methylenetetrahydrofolate reductase (MTHFR) gene polymorphism C677T, a risk factor for hypertension. Samples had been collected at baseline and following intervention with riboflavin, co‐factor for the MTHFR enzyme, as part of a placebo‐controlled double‐blind, randomized trial. The associations between miRNA expression and blood pressure at baseline and post‐intervention were investigated. Comparisons of data between CC and TT MTHFR genotype groups, and in response to intervention, were assessed using ANOVA, Pearson's correlation and corrected t‐test statistical analyses. Results: microRNA expression was successfully detected and quantifed in all samples. At baseline miR‐199a‐5p expression was inversely correlated (r=‐0.51;p