Association between endothelin-1 and diabetic retinopathy: a systematic review and meta-analysis

Diabetic retinopathy (DR) is a common chronic complication of diabetes mellitus. Endothelin-1 (ET-1) has been identified as a key regulator of various ocular functions, including vascular perfusion, aqueous humor dynamics, and retinal ganglion cell survival. Substantial evidence further underscores the critical involvement of ET-1 in the pathogenesis and progression of DR. Elevated ET-1 levels have been reported in patients with DR; however, findings across studies are inconsistent.

This meta-analysis aimed to statistically evaluate the level of ET-1 in patients with DR.

A systematic literature search was conducted across five electronic databases (PubMed, Web of Science, OVID, Elsevier Science Direct, and Wiley Online Library). The search strategy targeted the terms "Endothelin-1" or "ET-1" in conjunction with "Diabetic retinopathy" or "DR" in title and abstract fields. Results are presented as standardized mean differences (SMD) with 95% confidence intervals (CI).

Ten articles (346 cases and 425 controls) were included in the meta-analysis. The results of the meta-analysis indicated that the circulating ET-1 in patients with DR was significantly higher than that of the controls (SMD: 1.73, 95% CI: 0.90, 2.56). Furthermore, circulating ET-1 in patients with DR was also significantly higher than those in healthy individuals or diabetic patients without retinopathy, respectively.

This meta-analysis is the first to systematically assess ET-1 levels in patients with DR. The findings of this study indicate the potential application of ET-1 as a biomarker for monitoring DR progression.

https://www.crd.york.ac.uk/prospero/, identifier CRD420251156225.