Coagulation and inflammation in overt diabetic nephropathy: association with hyperhomocysteinemia

Diabetic nephropathy, especially when advanced, is associated with high prevalence of atherosclerotic cardiovascular disease in which inflammation and coagulation may play pathogenic roles. We investigated the relationships between diabetic nephropathy and coagulation, fibrinolysis, or inflammation in patients with Type 2 diabetes.

We evaluated markers of inflammation and coagulation in 105 Type 2 diabetic patients with various grades of nephropathy and 49 healthy control subjects, in association with plasma total homocysteine (tHcy) measurements.

Plasma tHcy concentrations were significantly higher in diabetic patients than in controls (8.96 +/- 3.04 vs. 6.92 +/- 1.36 micromol/l, P < 0.0001). Plasma concentrations of interleukin (IL)-6 were significantly higher in diabetic patients than in control subjects (P < 0.0001). In diabetic patients, plasma tHcy correlated positively with urinary albumin, fibrinogen, IL-6 and plasmin-alpha2-antiplasmin complex (PAP), while plasma tHcy correlated negatively with creatinine clearance (Ccr) and protein C activity. After adjustment for Ccr, IL-6 and protein C activity were significantly associated with plasma tHcy. Plasma tHcy concentrations were significantly higher in patients with overt albuminuria than in those with normoalbuminuria or microalbuminuria, as were plasma concentrations of fibrinogen, prothrombin F1+2, and interleukin-6.

Diabetic nephropathy is associated with elevated markers for both coagulation and inflammation. High plasma homocysteine may be a link between diabetic nephropathy and both chronic inflammation and hypercoagulability, increasing cardiovascular risk.