Relationship Between Circulating MicroRNAs and Left Ventricular Hypertrophy in Hypertensive Patients.

Objective: Left ventricular hypertrophy (LVH) is a common complication of hypertension and microRNAs (miRNAs) are considered to play an important role in cardiac hypertrophy development. This study evaluated the relationship between circulating miRNAs and LVH in hypertensive patients. Methods: Two cohorts [exploratory (n = 42) and validation (n = 297)] of hypertensive patients were evaluated by clinical, laboratory and echocardiography analysis. The serum expression of 754 miRNAs in the exploratory cohort and 6 miRNAs in the validation cohort was evaluated by the TaqMan OpenArray® system and quantitative polymerase chain reaction, respectively. Results: Among the 754 analyzed miRNAs, ten miRNAs (miR-30a-5p, miR-let7c, miR-92a, miR-451, miR-145-5p, miR-185, miR-338, miR-296, miR-375, and miR-10) had differential expression between individuals with and without LVH in the exploratory cohort. Results of multivariable regression analysis adjusted for confounding variables showed that three miRNAs (miR-145-5p, miR-451, and miR-let7c) were independently associated with LVH and left ventricular mass index in the validation cohort. Functional enrichment analysis demonstrated that these three miRNAs can regulate various genes and pathways related to cardiac remodeling. Furthermore, in vitro experiments using cardiac myocytes demonstrated that miR-145-5p mimic transfection up-regulated the expression of brain and atrial natriuretic peptide genes, which are markers of cardiac hypertrophy, while anti-miR-145-5p transfection abrogated the expression of these genes in response to norepinephrine stimulus. Conclusions: Our data demonstrated that circulating levels of several miRNAs, in particular miR-145-5p, miR-451, and let7c, were associated with LVH in hypertensive patients, indicating that these miRNAS may be potential circulating biomarkers or involved in hypertension-induced LV remodeling.

Association of carotid wall layers with atherosclerotic plaques and cardiac hypertrophy in hypertensive subjects.

Carotid intima-media thickness (cIMT) is considered a marker of subclinical atherosclerosis and is related to target-organ damage in hypertensive patients. However, increased cIMT may be due to increases in the thickness of intima (cIT) and media (cMT) layers. This study evaluated whether cIMT layers (cIT and cMT) had a greater association with carotid atherosclerotic plaques and left ventricular hypertrophy (LVH) than cIMT in hypertensive subjects. We cross-sectionally evaluated clinical, carotid, and echocardiography characteristics of 186 hypertensive patients followed at an outpatient clinic. High-resolution images of common carotid arteries were obtained by ultrasonography equipped with 10-MHz transducers, and cIT, cMT, and cIMT were manually measured using an image-processing software. Among all participants (n = 186; age = 60.8 ± 10.9 years, 43% males), there were 58% with carotid plaques and 58% with LVH. Mean cIT, cMT, and cIMT values were 0.267 ± 0.060, 0.475 ± 0.107, and 0.742 ± 0.142 mm, respectively. In logistic regression analysis adjusted for relevant covariates, carotid plaques showed stronger association with cIT than with cMT and cIMT. Furthermore, cIT showed greater area under the ROC curve (0.92; 95% CI 0.87-0.96) than cIMT (0.79; 95% CI 0.72-0.85) and cMT (0.64; 95% CI 0.56-0.72) to identify plaques. Conversely, cIT, cMT, and cIMT had modest association and accuracy to identify LVH (area under the ROC curve = 0.61, 0.57, and 0.60, respectively). In conclusion, cIT is a more accurate marker of atherosclerosis than cMT or cIMT, while cIT and cMT provide no incremental value in identifying LVH when compared with cIMT among hypertensive subjects.

Association of Circulating miR-145-5p and miR-let7c and Atherosclerotic Plaques in Hypertensive Patients.

AIM: Hypertension is a strong risk factor for atherosclerosis. Increased carotid intima-media thickness (cIMT) and carotid plaques are considered subclinical markers of atherosclerosis. This study aimed at evaluating the serum expression of miRNAs previously related to adverse vascular remodeling and correlating them with carotid plaques and cIMT in hypertensive patients. METHODS: We cross-sectionally evaluated the clinical and carotid characteristics as well as serum expression of miR-145-5p, miR-let7c, miR-92a, miR-30a and miR-451 in 177 hypertensive patients. Carotid plaques and cIMT were evaluated by ultrasound, and the expression of selected miRNAs was evaluated by a quantitative polymerase chain reaction. RESULTS: Among all participants (age = 60.6 ± 10.7 years, 43% males), there were 59% with carotid plaques. We observed an increased expression of miR-145-5p (Fold Change = 2.0, p = 0.035) and miR-let7c (Fold Change = 3.8, p = 0.045) in participants with atherosclerotic plaque when compared to those without plaque. In the logistic regression analysis adjusted for relevant covariates, these miRNAs showed a stronger association with carotid plaques (miR-145-5p: Beta ± SE = 0.050 ± 0.020, p = 0.016 and miR-let7c: Beta ± SE = 0.056 ± 0.019, p = 0.003). CONCLUSIONS: Hypertensive patients with carotid plaques have an increased expression of miR-145-5p and miR-let7c, suggesting a potential role of these miRNAs as a biomarker for subclinical atherosclerosis in hypertensive individuals.