Are there differences of inflammatory bio-markers between diabetic and non-diabetic patients with critical limb ischemia?

Aim: This observational study was undertaken in order to analyse whether any differences could be detected between diabetic and non-diabetic patients with critical limb ischemia (CLI) concerning the inflammatory response.

Methods: A total number of 259 consecutive patients with CLI were treated between October 2001 and January 2003.

Results: Among the 259 patients, 135 (52%) had diabetes, previously known in 123, and detected during hospitalization in 12. The diabetic patients more often showed gangrene (P<0.05) and infra-inguinal atherosclerosis (84% vs 67%, P=0.001). The patients with diabetes showed a better lipid profile (total cholesterol 4.6 vs 5 mmol/L, P=0.006 and lower LDL-cholesterol (2.7 vs 3.1 mmol/L, P=0.010) despite the same frequency of statin treatment. They showed a higher creatinine (149 vs 117 micromol/L, P=0.0003) than the non-diabetic patients. Of the inflammatory markers, C-reactive protein (CRP) was equally elevated in both groups. Tumor necrosis factor-a (TNF-a) was increased among the diabetic patients (2.6 vs 1.8 pg/mL, P<0.05), and this difference was most evident in those with gangrene. Neopterin was also higher among the diabetic patients (31 vs 21 mmol/L, P<0.01), but CD40L was not different between groups.

Conclusions: Diabetes mellitus was very common in CLI patients, and more often combined with renal impairment and infra-inguinal atherosclerosis. The inflammatory markers TNF-a and neopterin were elevated in patients with diabetes as compared to non-diabetic patients, but this difference cannot explain why CLI is 10 times more frequent in diabetic patients.