Plasma expression level of miRNA let-7 is positively correlated with carotid intima-media thickness in patients with essential hypertension.

MicroRNAs (miRNA, miR) play vital part in the pathophysiology of arterial remodeling in hypertension patients, and are increasingly becoming novel biomarkers in cardiovascular disease. The study was designed to evaluate the correlation between let-7 expression level and subclinical atherosclerosis in untreated patients with newly diagnosed essential hypertension. We assessed 240 participants including 60 healthy volunteers with normal carotid intima-media thickness (nCIMT), 60 healthy volunteers with increased CIMT (iCIMT), 60 hypertension patients with nCIMT and 60 hypertension patients with iCIMT. All patients underwent measurements of CIMT and ambulatory blood pressure (BP) monitoring. The level of let-7 was quantified using real-time reverse transcription polymerase chain reaction. Correlations of let-7 expression with BP parameters and CIMT were assessed using multiple linear regression analysis. We observed the lowest miRNA let-7 expression (21.70±1.45 vs 29.33±2.58 vs 31.50±1.80 vs 35.49±2.33; P<0.001) in healthy controls with nCIMT, followed by healthy controls with iCIMT, then hypertension patients with nCIMT and highest expression in hypertension patients with iCIMT. Let-7 was independently correlated with CIMT(r=0.587, P<0.001), and multiple linear regression analysis showed that let-7 was independently correlated with CIMT (β=0.031, P<0.001). Our findings provide significant evidence that plasma let-7 could represent a non-invasive marker for atherosclerosis in hypertensive patients and herald the emergence of a potential indicator to monitor end-organ damage in hypertension.