Novel Cardiovascular Risk Factors Do Not Completely Explain the Higher Prevalence of Peripheral Arterial Disease Among African Americans: The San Diego Population Study Original Research Article

Objectives This study was designed to determine whether novel cardiovascular disease (CVD) risk factors explain the high prevalence of peripheral arterial disease (PAD) among African Americans. Background Compared with Caucasians, African Americans have higher prevalence of PAD, an association that is not explained by traditional CVD risk factors. The degree to which novel CVD risk markers may explain the higher prevalence is uncertain. Methods A nested case-control study within the San Diego Population Study was performed. The study evaluated 104 persons with PAD and 164 age- and gender-matched control subjects who were employees of a large public university and participated in a peripheral artery and venous disease study. Nine novel CVD risk factors (homocysteine, lipoprotein (a), C-reactive protein, fibrinogen, tumor necrosis factor-alpha, von Willebrand factor, prothrombin fragment 1-2, D-dimer, and plasmin antiplasmin) were measured. Multivariable logistic regression evaluated whether these novel factors attenuated the association of African-American race and PAD and whether there was differential ethnic susceptibility to the novel factors. Results African Americans had 3-fold higher odds of PAD in age- and gender-matched models (odds ratio [OR] 3.1; 95% confidence interval [CI] 1.5 to 6.4; p < 0.01), an association that was modestly attenuated by adjustment for traditional (OR 2.4; 95% CI 0.9 to 6.1; p = 0.06) and novel CVD risk markers (OR 1.9; 95% CI 0.7 to 4.7; p = 0.18). Among the novel factors, the attenuation was primarily due to fibrinogen and lipoprotein (a). No interactions by novel CVD risk markers (both p values for interaction ≥0.24) were observed. Conclusions Traditional and novel CVD risk factors only partially explain the higher prevalence of PAD among African Americans.