Association between cystatin C and peripheral artery disease in the Chinese Han population.

BACKGROUND Recent studies of the association between cystatin C and peripheral artery disease (PAD) have produced inconsistent results, and few studies have been conducted to investigate this association in the Chinese Han population. Therefore, we evaluated the relationship between cystatin C and PAD using Chinese data. METHODS We performed a secondary analysis of the data from a previously published case-control study about PAD in our center. We examined the relationship between cystatin C and PAD by logistic regression models and subgroup and interaction analyses. We also constructed a propensity score-matched population by matching the conventional risk factors to further validate this association. In addition, we explored the relationship between cystatin C level and ankle-brachial index (ABI) strata (<0.4, ≥0.4) to shed light on a possible dose-dependent relationship between cystatin C levels and PAD severity. RESULTS In total, 426 participants were included for evaluation. The mean serum cystatin C concentration was significantly lower in the control group than that in the case group (1.06 ± 0.19 mg/L vs. 1.24 ± 0.34 mg/L, P < 0.001). After adjustment for conventional risk factors, the risk of PAD was significantly higher in individuals with a cystatin C level of ≥1.25 mg/L. A 17% higher risk of PAD was associated with each 100-μg/L increase in the serum cystatin C level. Similar results were seen in the analyses of the propensity score-matched population comprising 164 participants. Furthermore, patients with an ABI <0.4 had higher cystatin C level than those with an ABI ≥0.4 (1.31 ± 0.05 mg/L vs. 1.18 ± 0.03 mg/L, P = 0.03). CONCLUSIONS Our analysis indicated that an elevated cystatin C level is significantly associated with an increased risk of PAD in the Chinese Han population. Larger Chinese prospective cohort studies are needed to validate these findings.