Low Ankle-Brachial Index Associated With Rise in Creatinine Level Over Time

Background: A low ankle-brachial index (ABI) predicts risk of cardiovascular death, myocardial infarction, peripheral arterial disease events, and stroke. However, it is unknown whether a low ABI also predicts a decline in renal function. Methods:WeexaminedtheassociationbetweenABIand changeinserumcreatininelevelovertimeamong13655 participants in the Atherosclerosis Risk in Communities (ARIC) study who underwent serum creatinine and ABI measurement at baseline and also underwent serum creatinine measurement 3 years later at the second study visit. The study outcome was a 50% rise in serum creatinine level from baseline to the second study visit. Results: Overall, 0.48% of participants with an ABI of 1 or higher, 0.9% of participants with an ABI between 0.9and0.99,and2.16%ofparticipantswithanABIlower than 0.9 experienced a 50% or greater increase in serum creatininelevel.Inmultivariateanalysis,participantswith an ABI lower than0.9 were still more thantwice as likely as those in the referent category (ABI 1) to experience anincreaseinserumcreatininelevel(oddsratio2.5;95% confidence interval, 1.1-5.7) (P=.04), and a linear trend in the incidence of worsening renal function was noted across ABI categories (P=.02). Analyses excluding participants with renal insufficiency, diabetes, and hypertension at baseline all produced similar results. Conclusion: In addition to known associations of the ABI with stroke, myocardial infarction, peripheral arterial disease events, and cardiovascular death, a low ABI also predicts an increase in serum creatinine level over time. Arch Intern Med. 2005;165:1481-1485