Circulating Wnt1-inducible signaling pathway protein-1 (WISP-1/CCN4) is a novel biomarker of adiposity in subjects with type 2 diabetes

Background Wnt1-inducible signaling pathway protein 1, or cellular communication network factor 4 (CCN4), a member of CCN family of secreted, extracellular matrix associated signaling proteins, recently was validated as a novel adipose tissue derived cytokine. Objective To assess the relationships between circulating CCN4, adipose tissue distribution and function, and chronic low-grade inflammation in subjects with type 2 diabetes. Methods We observed 156 patients with type 2 diabetes and 24 healthy controls. Serum levels of CCN4, hsCRP and alpha1-acid glycoprotein (alpha1-AGP) were measured by ELISA. Serum concentrations of leptin, resistin, visfatin, adipsin, adiponectin, IL-6, IL-8, IL-18 and TNF-alpha were determined by multiplex analysis. Fat mass and distribution was assessed by DEXA. Mean diameter of adipocytes was estimated in samples of subcutaneous adipose tissue. Results Patients with diabetes had higher levels of circulating CCN4, leptin, resistin, adipsin, visfatin, hsCRP, alpha1-AGP, and IL-6 (all p < 0.02). The CCN4 concentration correlated positively with percentage of fat mass in central abdominal area, as well as with leptin, resistin and visfatin levels; negative correlation was found between CCN4 and mean adipocyte diameter. In multiple regression analysis fat mass in central abdominal area was independent predictor for CCN4 concentration. Conclusion In subjects with type 2 diabetes serum levels of CCN4 are associated with central abdominal fat mass and adipose tissue dysfunction.