Association between circulating microRNAs and changes in kidney function: A five-year prospective study among Japanese adults without CKD

Background: Although a number of microRNAs (miRNA) reflecting kidney function has been identified, prospective studies are now urgently needed to determine a clinical utility of these miRNAs among general populations. The purpose of this study was to examine the associations between serum miRNAs and kidney function in a population-based study. Methods: We conducted a five-year prospective study (2012–2017) of 169 individuals without chronic kidney disease (CKD) at the baseline survey (mean age, 62.5; 96 women). The real-time qPCR was used to measure serum levels of five previously reported miRNAs. Participants with eGFR < 60 mL/min/1.73 m² were defined as having CKD. Changes in eGFR were defined as eGFR₂₀₁₇ − eGFR₂₀₁₂. Results: After adjusting for covariates including baseline eGFR, lower serum levels (1st tertile) of miR-126 were associated with a greater decline of eGFR (β [SE] = −3.18 [1.50]) and a higher odds ratio (OR) of CKD onset over five years (OR [95% CI] = 3.85 [1.01–16.8]), compared with the 3rd tertile. Conclusions: We found baseline serum miR-126 levels were associated with changes in eGFR and new CKD cases in a five-year prospective study. This result suggests that miR-126 may be a potential biomarker of CKD even among general populations.