Serum microRNA-126 Levels Are Associated With Diabetic Nephropathy in Patients With Type 2 Diabetes Mellitus

Diabetic nephropathy (DN) occurs in nearly 40% of Type 2 diabetes mellitus (T2DM) patients, and there is a positive correlation between DN and terminal renal disease. Thus, exploring novel biomarkers is vital to facilitate early diagnosis and intervention in DN patients; however, indicators of DN are still scant. Since the microRNA-126 (miR-126) may be related to the occurrence of diabetes, we aim to assess the association between miR-126 and DN.

This is a prospective cohort design and a nested case-control approach study that enrolled 300 individuals (100 T2DM patients, 100 DN patients, and 100 controls). miR-126 expression was analyzed by quantitative real-time PCR (qPCR) and compared among three groups. The overall survival (OS) was presented by Kaplan-Meier analysis. The area under the curve (AUC) was used to evaluate the potential of miR-126 as a biomarker for DN.

DN patients, compared with T2DM and controls, had lower miR-126 content (p < 0.001), and miR-126 levels significantly decreased following a decreasing estimated glomerular filtration rate (eGFR) (r = 0.65, p < 0.001). Moreover, significant differences were also found in OS among quartiles of serum miR-126 level (p for trend < 0.001). In addition, the AUC for diagnosis DN from T2DM patients was found to be 0.804 (95% CI, 0.745-0.863), with a sensitivity of 83.0% and a specificity of 63.0%.

This study provides evidence to clarify that decreased levels of miR-126 were linked to an increased susceptibility to developing DN compared with healthy volunteers. More importantly, the diagnostic role of miR-126 remained significant in differentiating DN from T2DM patients.