Circulating miRNA29 family expression levels in patients with essential hypertension as potential markers for left ventricular hypertrophy.

OBJECTIVES: The role of microRNAs (miRs,miRNAs) in the pathogenesis of cardiovascular diseases such as hypertension, as well as their diagnostic potential, has recently attracted much attention. However, target-organ damage (TOD) of hypertension remains a substantial challenge due to the lack of specific biomarkers. The present study was undertaken to identify and validate the potential of circulating miRs as novel biomarkers for TOD. METHODS: We assessed the expression levels of miR-29a, miR-29b, and miR-29c in 54 patients with untreated essential hypertension and 30 healthy individuals. All patients underwent two-dimensional echocardiography, office, and ambulatory blood pressure monitoring. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was used to evaluate the expression of selected miRs. The expression level of miR-29a, miR-29b, and miR-29c correlations between blood pressure and echocardiography parameters were assessed using the Spearman correlation coefficient. RESULTS: We observed higher expression levels of miR-29a (31.50 ± 3.90 vs 26.55 ± 1.74; p < 0.001), miR-29b (32.31 ± 2.85vs 27.21 ± 1.59; p < 0.001), and miR-29c (31.13 ± 3.42 vs 25.96 ± 1.88; p < 0.001) in hypertensive patients compared with healthy control individuals. In hypertension patients, 25 patients were left ventricular hypertrophy (LVH), miR-29a (32.82 ± 4.06 vs 30.07 ± 3.68; p = 0.012), miR-29b (33.27 ± 2.84 vs 30.71 ± 3.04; p = 0.02), and miR-29c (32.33 ± 3.52 vs 29.55 ± 3.46; p = 0.005) in LVH patients compared with nLVH patients. We found miR-29a, miR-29b, and miR-29c expression levels showed significant positive correlations with office SBP (p = 0.579, p < 0.001; r = 0.576, p < 0.001; r = 0.598, p < 0.001), office DBP (p = 0.243, p = 0.026; r = 0.304, p = 0.005; r = 0.287, p = 0.008), office PP(r = 0.49, p < 0.001; r = 0.442, p < 0.001; r = 0.479, p < 0.001), 24 h mean SBP(p = 0.511, p < 0.001; r = 0.6, p < 0.001; r = 0.533, p < 0.001), 24 h mean DBP (p = 0. 304, p = 0.005; r = 0.283, p = 0.009; r = 0.340, p = 0.002), and 24 h mean PP (p = 0.385, p < 0.001; r = 0. 506, p < 0.001; r = 0.386, p < 0.001), respectively. The expression levels of miR-29a, miR-29b, and miR-29c were positively related to LVMI (r = 0.65, p < 0.001; r = 0.715, p < 0.001; r = 0.654, p < 0.001), respectively. CONCLUSION: Circulating the miR-29 family may possibly represent potential non-invasive markers of hypertension and TOD in essential hypertensive patients.