Lower Modified Creatinine Index and Risk of Intervention for Lower Extremity Arterial Disease in Hemodialysis Patients: Ten-Year Outcomes of the Q-Cohort Study.

BACKGROUND & AIMS: Lower extremity arterial disease (LEAD) is highly prevalent among patients undergoing hemodialysis. We examined whether a lower modified creatinine (Cr) index, a surrogate marker related to skeletal muscle mass, was associated with intervention for LEAD. METHODS: In total, 3,492 patients receiving maintenance hemodialysis were followed for 10 years in a multicenter observational cohort. The primary outcome was the first intervention for LEAD, including endovascular therapy, revascularization, or amputation. The primary exposure was the modified Cr index, a surrogate for skeletal muscle mass. Patients were divided into sex-specific quartiles according to the baseline modified Cr index. Cox proportional hazards models were used to examine the association between the modified Cr index and intervention for LEAD. RESULTS: During a median follow-up of 8.2 years, 256 patients underwent intervention for LEAD. In the multivariable-adjusted model, the risks of intervention for LEAD were higher in Q1 and Q2 than in Q4: hazard ratios (95% confidence intervals) were 1.75 (1.01-3.04) and 1.63 (1.03-2.57), respectively. Each 1-mg/kg/day decrease in the modified Cr index was associated with an elevated risk of intervention for LEAD, with a hazard ratio of 1.12 (1.02-1.23). Sensitivity analyses excluding early LEAD interventions showed directionally consistent but attenuated associations. CONCLUSIONS: A lower modified Cr index was associated with a higher long-term risk of intervention for LEAD. Because baseline ankle-brachial index and direct muscle measurements were unavailable, these findings should be interpreted as an association rather than evidence that low skeletal muscle mass causes LEAD.