Serum-derived microribonucleic acids as potential novel biomarkers for slowly progressive type 1 diabetes mellitus

We aimed to identify microribonucleic acids (miRNAs) that could serve as biomarkers for slowly progressive type 1 diabetes mellitus (SPIDDM).

We conducted a retrospective study of adult patients with SPIDDM who fulfilled the criteria for SPIDDM (definite) (n = 60), type 2 diabetes mellitus (T2DM) (n = 59), and healthy controls (n = 50) to analyze the serum expression levels of 40 miRNAs reported to be altered in latent autoimmune diabetes in adults and type 1 diabetes using quantitative real-time polymerase chain reaction, specifically analyzing serum collected at the time of diagnosis as SPIDDM (probable) in the SPIDDM group. For miRNAs showing significant differences between the groups, we performed logistic regression analysis. In the SPIDDM group, we performed linear regression analysis on miRNAs correlated with the C-peptide index (CPI) at the last outpatient visit as identified by Spearman's rank correlation.

The serum expression levels of miR-143-3p, miR-21-5p, miR-223-3p, and miR-517b-3p differed significantly in the SPIDDM group compared with the type 2 diabetes mellitus and control groups. Multivariate logistic regression analysis distinguishing SPIDDM from type 2 diabetes mellitus revealed miR-21-5p, miR-223-3p, and miR-517b-3p as independent discriminators. Correlation and multivariate linear regression analyses revealed that miR-150-5p was selected as an independent predictor of CPI at the last outpatient visit.

This study identified serum miRNAs as potential biomarkers in adult patients with SPIDDM, particularly miR-150-5p as a candidate marker for predicting subsequent decline in insulin secretion.