Ali, Zeenat

Abstract Myeloperoxidase (MPO) is an enzymatic mediator of several inflammatory cascades and higher serum levels have been associated with increased risk of adverse cardiovascular events. We investigated the association of serum MPO with the ankle–brachial index (ABI) and peripheral arterial disease (PAD) in a bi-ethnic cohort of African-Americans and non-Hispanic white individuals. Participants included 1324 African-Americans (mean age 64 years, 71% women) and 1237 non-Hispanic white individuals (mean age 59 years, 57% women) belonging to hypertensive sibships. Serum levels of MPO were measured by solid phase sandwich immunoassay. ABI was measured using a standard protocol and PAD was defined as an ABI < 0.90. Multivariable regression analysis using generalized estimating equations were performed to assess whether serum MPO levels were associated with ABI and the presence of PAD. After adjustment for age and sex, higher MPO levels were significantly associated with lower ABI and the presence of PAD in African-Americans ( p = 0.004 and p = 0.005, respectively) and in non-Hispanic white individuals ( p = 0.001 and p = 0.016, respectively). After additional adjustment for conventional risk factors (diabetes, smoking status, total and high-density lipoprotein cholesterol, waist circumference, hypertension), prior history of myocardial infarction or stroke, and medication use (statins, aspirin, estrogen), higher MPO levels remained significantly associated with lower ABI and the presence of PAD in both African-Americans ( p = 0.008 and p = 0.010, respectively) and non-Hispanic white individuals ( p = 0.001 and p = 0.018, respectively). We conclude that higher MPO levels are associated with lower ABI and the presence of PAD in African-Americans and non-Hispanic white individuals.

Abstract Background: Higher plasma concentrations of soluble adhesion molecules have been shown to be associated with increased risk of cardiovascular events. We investigated the association of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) with ankle-brachial index (ABI), a measure of peripheral arterial disease (PAD), in a biethnic cohort of adults without known coronary heart disease or stroke. Methods: Participants included 1102 blacks (mean age, 63 years; 74% women) and 1013 non-Hispanic whites (mean age, 58 years; 59% women) belonging to sibships ascertained on the basis of hypertension. We measured plasma concentrations of sICAM-1 and sVCAM-1 using high-sensitivity immunoassays and ABI using a standard protocol; PAD was defined as ABI &lt;0.9. We used generalized estimating equations to assess whether sICAM-1 and sVCAM-1 were associated with ABI and PAD, independently of conventional risk factors. Results: After adjustment for conventional risk factors, blacks with sICAM-1 and sVCAM-1 concentrations in the highest quartiles had lower ABIs than those in the lowest quartiles (mean ABI 1.02 vs 0.98, P = 0.007, vs 1.02 vs 0.99, P = 0.003, respectively). In multivariable logistic regression analysis, sICAM-1 and sVCAM-1 concentrations in the highest quartiles were each associated with a higher odds ratio of having PAD, compared with the lowest quartiles: odds ratio (95% CI): 5.2 (1.8–15.2) and 2.2 (1.0–4.8), respectively. In contrast, in non-Hispanic whites, sICAM-1 and sVCAM-1 concentrations were not associated with ABI or PAD. Conclusions: Higher sICAM-1 and sVCAM-1 concentrations were independently associated with lower ABI and PAD in blacks, but not in non-Hispanic whites.