Effects of Continuous and Interval Aerobic Exercise on MicroRNA-146a and MicroRNA-126 Levels in Women with Atherosclerosis

Abstract

Background: Atherosclerosis is a chronic inflammatory vascular disease characterized by endothelial dysfunction and altered expression of regulatory microRNAs. Among these, microRNA-126 (miR-126) and microRNA-146a (miR-146a) play important roles in angiogenesis, endothelial repair, and the modulation of inflammatory pathways. Objectives: This study investigated the effects of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on circulating levels of miR-126 and miR-146a in women with atherosclerosis. Methods: In this randomized controlled trial, 45 women with clinically diagnosed atherosclerosis were randomly assigned to the control, MICT, or HIIT group (n = 15 each). Exercise interventions were performed three times per week for 12 weeks. Blood samples were collected at baseline and after 6 and 12 weeks. Circulating miR-126 and miR-146a expression levels were measured using quantitative real-time PCR (qRT-PCR). Other cardiovascular and physiological variables were assessed for safety and participant characterization purposes and were not predefined efficacy endpoints. Data were analyzed using linear mixed models with Bonferroni post hoc tests. Results: Significant time × group interactions were observed for both miR-146a (F = 35.5, P < 0.001, η = 0.53) and miR-126 (F = 33.1, P < 0.001, η = 0.52). Both HIIT and MICT significantly increased circulating levels of miR-146a and miR-126 compared with those in the control group (P < 0.001). Although the overall increases after 12 weeks were comparable between the exercise modalities, HIIT induced earlier elevations in both microRNAs during the first 6 weeks, whereas MICT produced a more gradual but sustained increase during the latter phase of the intervention. Conclusions: Twelve weeks of aerobic exercise increased circulating miR-126 and miR-146a in women with atherosclerosis. Although both training modalities produced similar long-term benefits, HIIT elicited more rapid molecular adaptations. These findings suggest that aerobic exercise may promote vascular health through favorable epigenetic modulation and support the use of individualized exercise prescriptions for cardiovascular rehabilitation.