Endocan and albuminuria in type 2 diabetes mellitus

Endocan is a newly identified proteoglycan released from endothelium, stimulating angiogenesis and when increased, indicates endothelial activation (inflammation). Our aim was to examine the association between serum endocan levels and urine albumin-creatinine ratio (UACR).

One hundred and thirty-seven patients with type 2 diabetes mellitus and normal serum creatinine who had no co-morbidities other than hypertension, diabetic nephropathy, retinopathy, or neuropathy were divided into normoalbuminuria (G1), microalbuminuria (G2), and macroalbuminuria (G3) groups and compared cross-sectionally regarding serum endocan levels.

There were 55, 47, and 35 patients in G1, G2, and G3, respectively. The groups were comparable in terms of gender, age, duration of diabetes, diabetic neuropathy/retinopathy, fasting glucose, HbA1c, serum creatinine level, and eGFR. Patients in G3 had significantly higher blood pressure but lower serum albumin and endocan levels. UACR showed a negative bivariate correlation with serum endocan levels (r = -.282, p = .001). There was bivariate positive correlation between endocan and systolic blood pressure (r=.185, p = .030). In linear regression analysis, UACR was negatively correlated with endocan while positively correlated with systolic blood pressure, duration of diabetes, and platelet distribution width.

Patients with macroalbuminuria had lower endocan levels, and increasing UACR was associated with decreasing serum endocan levels. Despite the occurrence of angiogenesis and glomerular hypertrophy in the early phase of diabetic nephropathy, ensuing significant renal injury over time may reduce the expression of endocan. Serum endocan levels may represent a novel marker for nephropathy progression.