b2-Microglobulin, Cystatin C, and Creatinine and Risk of Symptomatic Peripheral Artery Disease

Methods and Results-—We conducted nested case-control studies among women within the Nurses’ Health Study (1990–2010) and among men within the Health Professionals Follow-up Study (1994–2008) with the use of archived blood samples collected before PAD diagnosis. During follow-up, symptomatic PAD was confirmed in 144 women and 143 men. Controls were matched 3:1 based on age, race, smoking status, fasting status, and date of blood sampling. Conditional logistic regression models were used to estimate relative risks (RRs) and were adjusted for plasma creatinine and cardiovascular risk factors. In women, the RRs (95% CI) per 1-SD) increment were 1.16 (0.85 to 1.58) for b2-microglobulin and 0.94 (0.69 to 1.28) for cystatin C. Corresponding RRs in men were 1.50 (1.08 to 2.09) for b2-microglobulin and 1.54 (1.07 to 2.22) for cystatin C. There was no association between creatinine and PAD risk in women, whereas the association in men (RR 1.41, 95% CI 1.10 to 1.81) disappeared after adjustment for either b2-microglobulin or cystatin C. In pooled analyses of men and women, only b2-microglobulin was associated with PAD risk (RR 1.31, 95% CI 1.04 to 1.64).