Relationship between the plasma concentration of C-reactive protein and severity of peripheral arterial disease.

Objective: To determine whether the increase in plasma levels of C-Reactive Protein (CRP), a non-specific reactant in the acute-phase of systemic inflammation, is associated with clinical severity of peripheral arterial disease (PAD).

Methods and results: This is a cross-sectional study at a referral hospital center of institutional practice in Madrid, Spain. A stratified random sampling was done over a population of 3370 patients with symptomatic PAD from the outpatient vascular laboratory database in 2007 in the order of their clinical severity: the first group of patients with mild chronological clinical severity who did not require surgical revascularization, the second group consisted of patients with moderate clinical severity who had only undergone only one surgical revascularization procedure and the third group consisted of patients who were severely affected and had undergone two or more surgical revascularization procedures of the lower extremities in different areas or needed late re-interventions. The Neyman affixation was used to calculate the sample size with a fixed relative error of 0.1. A homogeneity analysis between groups and a unifactorial analysis of comparison of medians for CRP was done. The groups were homogeneous for age, smoking status, Arterial Hypertension HTA, diabetes mellitus, dyslipemia, homocysteinemia and specific markers of inflammation. In the unifactorial analysis of multiple comparisons of medians according to Scheffé, it was observed that the median values of CRP plasma levels were increased in association with higher clinical severity of PAD (3.81 mg/L [2.14-5.48] vs. 8.33 [4.38-9.19] vs. 12.83 [9.5-14.16]; p < 0.05) as a unique factor of tested ones.

Conclusion: Plasma levels of CRP are associated with not only the presence of atherosclerosis but also with its chronological clinical severity.