Abstract
Background: Hypertensive cardiomyopathy (HC) is a progressive condition characterized by left ventricular remodeling secondary to prolonged hypertension. Early detection is particularly crucial in young hypertensive adults (<45 years), who may remain asymptomatic until advanced structural changes occur. Circulating exosomal microRNAs (miRNAs) have emerged as stable, non-invasive biomarkers reflecting pathologic cardiac remodeling.
Objective: To systematically evaluate and meta-analyze studies assessing the predictive utility of circulating exosomal miRNAs—specifically miR‑21 and miR‑29b—for hypertensive cardiomyopathy in young adults.
Methods: We searched PubMed, Embase, Cochrane Library, and Web of Science for human adult studies (18–45 years) published between January 2000 and May 2025, investigating exosomal miRNAs and echocardiographic cardiac parameters. Two reviewers independently screened studies, extracted data, and assessed quality via Newcastle‑Ottawa Scale. Continuous outcomes (e.g., left ventricular mass index, LVMI) were pooled using weighted mean difference (WMD). Diagnostic test accuracy (sensitivity, specificity, pooled area under the ROC curve) was evaluated using hierarchical summary ROC modeling.
Results: Twelve studies met eligibility, comprising a combined cohort of 1,865 young adults (1,020 hypertensive with signs of cardiac remodeling; 845 controls). Meta-analysis revealed that elevated exosomal miR‑21 levels were significantly associated with higher LVMI (WMD = 3.84 g/m²; 95% CI 2.11–5.56; p < 0.001; I² = 38%). Similar associations were seen for miR‑29b (WMD = 3.15 g/m²; 95% CI 1.10–5.20; p = 0.003; I² = 45%). Diagnostic accuracy meta-analysis for exosomal miR‑21 indicated pooled sensitivity of 0.78 (95% CI 0.71–0.84), pooled specificity of 0.75 (95% CI 0.68–0.81), yielding an AUC of 0.82 (95% CI 0.77–0.86).
Conclusion: Circulating exosomal miR‑21 and miR‑29b show robust association with early hypertensive cardiomyopathy in young adults and demonstrate solid diagnostic potential. These miRNAs may serve as valuable biomarkers for early detection, though longitudinal validation in large, standardized cohorts is needed.