Circulating MicroRNA-486 and MicroRNA-146a serve as potential biomarkers of sarcopenia in the older adults

Background: Age-related sarcopenia meaningfully increases the risks of functional limitations and mortality in the older adults. Although circulating microRNAs (c-miRNAs) are associated with aging-related cellular senescence and inflammation, the relationships between c-miRNAs and sarcopenia in the older adults remain unclear. This study investigates whether circulating myo-miRNAs and inflammation-related miRNAs are associated with sarcopenia in the older adults. Methods: This investigation recruited 77 eligible subjects (41 males and 36 females) from 597 community-dwelling older adults, and then divided them into normal (n = 24), dynapenic (loss of muscular function without mass, n = 35), and sarcopenic groups (loss of muscular function with mass, n = 18). Moreover, myo- (c-miRNA-133a and c-miRNA-486) and inflammation- (c-miRNA-21 and c-miRNA-146a) related miRNAs, as well as, inflammatory-related cytokine and peroxide levels in plasma were determined using quantitative polymerase chain reaction and ELISA, respectively. Results: Sarcopenic group exhibited lesser skeletal muscle mass index (SMI), handgrip strength, and gait speed, as well as, lower c-miR-486 and c-miR-146a levels, compared to those of normal and dynapenic groups. Moreover, c-miR-486 level was positively related to SMI (r = 0.334, P = 0.003), whereas c-miR-146a level was positively associated with SMI (r = 0.240, P = 0.035) and handgrip strength (r = 0.253, P = 0.027). In the receiver operating characteristic analysis for predicting sarcopenia, the area under the curve in c-miR-486 was 0.708 (95% confidence interval: 0.561–0.855, P = 0.008) and c-miR-146a was 0.676 (95% CI: 0.551–0.801, P = 0.024). However, no significant relationships were observed between SMI/handgrip strength/gait speed and plasma myeloperoxidase/interleukin-1훽/interleukin-6 levels. Conclusions: Myo-miRNA (c-miR-486) and inflammation-related miRNA (c-miR-146a) are superior to inflammatory peroxide/cytokines in plasma for serving as critical biomarkers of age-related sarcopenia.