Relationship between serum cystatin C and serum adiponectin level in type 2 diabetic patients

To investigate the relationship between serum levels of cystatin C and adiponectin in patients with type 2 diabetes. We examined serum cystatin C and adiponectin levels in 234 patients with type 2 diabetes who visited our hospital. The serum level of cystatin C was positively correlated with age (P < 0.001), duration of diabetes (P = 0.013), serum creatinine (P < 0.001), uric acid (P < 0.001), and adiponectin (p = 0.001), while it was inversely correlated with estimated glomerular filtration rate (P < 0.001). Serum adiponectin was significantly higher in patients with high serum cystatin C levels than in those with normal cystatin C levels (8.3 +/- A 4.7 and 6.2 +/- A 3.2 mu g/mL, respectively; P < 0.001). Adiponectin was also significantly higher in male patients with high cystatin C levels, but not in females. In multiple regression analysis, serum adiponectin was also independently and significantly correlated to age, diastolic blood pressure, high-density lipoprotein cholesterol, triglyceride and serum cystatin C. Serum adiponectin level was correlated with serum cystatin C level on simple and multiple regression analyses in patients with type 2 diabetes. Although circulating adiponectin is increased in advanced kidney disease, it might be biologically inactive due to binding to cystatin C and thus not display an anti-arteriosclerotic effect.