Circulating miR-16 as an Early Biomarker of Subclinical Myocardial Strain Impairment in Pediatric Primary Hypertension

The role of circulating microRNAs in the pathophysiology of cardiac remodeling in primary hypertension (PH) remains incompletely understood. Left ventricular global longitudinal strain (LV GLS) is a sensitive marker of subclinical systolic dysfunction and can be used to monitor early cardiac involvement in cardiovascular and renal diseases. To the best of our knowledge, this is the first study to demonstrate an association between circulating miR-16 and LV GLS in children. The study aimed to evaluate the expression levels of miR-16-5p, -21-5p, -27a-3p, -27b-3p, -133a-3p, and -145-5p in untreated children with PH and examine their associations with LV GLS. 50 children with PH and 57 normotensive controls were evaluated for circulating microRNA expression levels and echocardiographic parameters, including LV GLS. Comprehensive anthropometric, biochemical, blood pressure, and arterial indices were also assessed. Among the analyzed microRNAs, miR-16-5p exhibited a positive association with LV GLS (R = 0.305, p = 0.031), whereas miR-27b-3p demonstrated a negative association (R = −0.330, p < 0.001). Compared with controls, hypertensive children exhibited significantly higher (i.e., less negative) LV GLS (r = 0.29, p = 0.002), indicating early systolic dysfunction occurring already at an early stage of the disease. In conclusion, these findings support the idea that specific microRNAs might play a differential role in early myocardial functional alterations in pediatric PH. Higher miR-16 expression levels may be associated with impaired myocardial deformation, potentially reflecting its involvement in early maladaptive myocardial remodeling. Furthermore, LV GLS may represent a sensitive and clinically informative marker of early myocardial dysfunction beyond traditional echocardiographic parameters in this population.