Patterns of inflammation associated with peripheral arterial disease: The InCHIANTI study

Objective: To determine whether peripheral arterial disease is associated with high circulating levels of pro-inflammatory cytokines, independent of confounders. Methods: Participants were 955 men and women aged 60 years and older representative of the population in 2 Italian communities (107 with peripheral arterial disease). Measurements included the ankle brachial index, comorbidities, total cholesterol and high-density lipoprotein cholesterol (HDL-C) levels, and these inflammatory factors: albumin, α-2 macroglobulin, C-reactive protein, fibrinogen, interleukin (IL)-1β, IL-1 receptor antagonist, IL-6, IL-6 receptor, IL-10, IL-18, tumor necrosis factor α, and transforming growth factor β. Results: Adjusting for age, sex, body mass index, smoking, comorbidities, HDL-C, and total cholesterol, participants with peripheral arterial disease had higher levels of IL-1 receptor antagonist (147.97 vs 131.24 pg/mL, P = .002), IL-6 (1.65 vs 1.37 pg/mL, P = .026), fibrinogen (362.49 vs 345.50 mg/dL, P = .039), and C-reactive protein (3.18 vs 2.56 mg/dL, P = .043) compared with those without peripheral arterial disease. These associations were attenuated after additional adjustment for physical activity. Conclusion: In a community population, peripheral arterial disease is associated with increased circulating levels of IL-6, IL-1 receptor antagonist, fibrinogen, and C-reactive protein compared to persons without peripheral arterial disease. Further study is needed to determine whether reducing levels of certain inflammatory factors lowers the incidence and progression of peripheral arterial disease.