Soluble TNFR1 Levels in Type 2 Diabetes and its Association with Stages of Proteinuria.

Abstract

Early identification of at-risk individuals for diabetic nephropathy would help in preventing or delaying end-stage renal failure. We measured the levels of circulating soluble tumor necrosis factor receptor 1 (sTNFR1) in various stages of proteinuria (MAC) to determine the association of this marker with diabetic nephropathy. The study was performed on 160 subjects, and a case-control methodology was employed. Type 2 diabetic subjects were recruited based on albuminuria and were grouped as (1) normoalbuminuria (NA); (2) microalbuminuria (MIC); (3) MAC; (4) normal glucose tolerance (NGT) subjects who served as healthy controls. sTNFR1 levels were measured by quantitative enzyme-linked immunosorbent assay (ELISA). Soluble tumor necrosis factor receptor 1 (sTNFR1) levels were highest in the MAC group, followed by the microMAC group. The sTNFR1 levels were not statistically different between the NGT and NA groups. On regression models, sTNFR1 was associated with MIC [odds ratio (OR)- 6.491, 95% confidence interval (CI)-1.868-22.55] and MAC (OR per standard deviation-15.28; 95% CI-3.76-62.15; p < 0.001) even after controlling for all the possible confounding factors. Receiver operator curve (ROC) analysis revealed sTNFR1 cut-point of 1832 pg/mL had a C-statistic of 0.685 to discriminate MI from NA with 52% sensitivity. Whereas the sTNFR1 cut-point of 2050 pg/mL with a C-statistic of 0.8177 had 77% sensitivity for identifying MAC. Soluble tumor necrosis factor receptor 1 (sTNFR1) is significantly associated with MIC and MAC group in type 2 diabetes, and this suggests a potential early diagnostic biomarker role of sTNFR1 for MAC among Asian Indians.