Clinical implication of plasma and urine YKL-40, as a proinflammatory biomarker, on early stage of nephropathy in type 2 diabetic patients.

OBJECTIVE

Chronic inflammation has emerged as being a key pathophysiology in the early stages of diabetic nephropathy. YKL-40 has been established as an inflammatory marker in chronic inflammation. The aim of this study was to evaluate the association of plasma and urine YKL-40 with albuminuria in the early stage of type 2 diabetic nephropathy.

DESIGN AND METHODS

A total of 75 type 2 diabetic patients and 22 nondiabetic controls with estimated glomerular filtration (eGFR) ≥60 ml/min/1.73 m(2) were enrolled. Plasma and urine concentrations of YKL-40 were analyzed by ELISA kit.

RESULTS

The plasma levels of YKL-40 were significantly higher in the normoalbuminuric group with diabetes than in the control group, and increased with increasing severity of albuminuria among diabetes. However, urine YKL-40 was only increased in macroalbuminuric state. Plasma YKL-40 was positively correlated with urine YKL-40 (r=0.291, P=0.011). Urinary albumin significantly correlated with both plasma and urine YKL-40 in a univariate analysis. After adjusting for several confounding factors, plasma YKL-40 was significantly correlated with albuminuria (r=0.359; P=0.001), whereas urine YKL-40 did not show significant correlation with albuminuria (r=0.128, P=0.241).

CONCLUSIONS

Although urine YKL-40 has a limited role, plasma YKL-40, as an proinflammatory marker, was an independent factor associated with albuminuria in early stage of nephropathy in type 2 diabetes and might have an useful role as a noninvasive marker for the early diabetic nephropathy detection.