Background: Diabetic retinopathy (DR) pathophysiology involves insulin resistance, oxidative stress, inflammation but mechanism remains unclear. Also, there is lack of reliable circulatory biomarkers for early diagnosis of DR especially vision threatening retinopathy (VTDR).
Objectives: To study the role of adipokines (omentin-1, apelin & chemerin) in the pathophysiology of DR in T2DM patients and to analyze their potential as the novel circulating biomarkers of DR and VTDR.
Methods: 168 T2DM patients were grouped equally into no DR (NDR), non-proliferative DR (NPDR) and proliferative DR (PDR). Severe NPDR and PDR were taken together as VTDR. Serum omentin-1, apelin and chemerin and related parameters were measured.
Results: Omentin-1 levels in NPDR and PDR groups were low compared to NDR. Chemerin and apelin level in PDR were high compared to NDR. Spearman’s correlation showed omentin-1, apelin, chemerin were significantly associated with DR severity. Bivariate analysis showed omentin-1 had a negative correlation with triglycerides, Hs-CRP and triglyceride-glucose index (TyG) but positive correlation with HOMA-beta; while apelin correlated positively with chemerin. ROC curve analyses revealed that omentin-1, apelin, chemerin were associated with DR and VTDR. Serum apelin level was higher in males compared to females.