Modified creatinine index and risk for cardiovascular events and all-cause mortality in patients undergoing hemodialysis: The Q-Cohort study

Abstract

Background and aimsThe modified creatinine (Cr) index, calculated by age, sex, pre-dialysis serum Cr levels, and Kt/V for urea, reflects skeletal muscle mass in patients on hemodialysis. Whether the modified Cr index is associated with cardiovascular events and all-cause mortality remains unknown. MethodsA total of 3027 patients registered in the Q-Cohort Study, a multicenter, prospective study of patients on hemodialysis in Japan, were analyzed. The main outcomes were cardiovascular events and all-cause mortality. Associations between sex-specific quartiles of the modified Cr index and outcomes were analyzed by the Cox proportional hazard models and the Fine–Gray proportional subdistribution hazards model. ResultsThe modified Cr index was correlated with known nutritional and inflammatory markers. During a 4-year follow-up, 499 patients died of any cause, 372 experienced heart disease, and 194 developed stroke. The risk for all-cause mortality was significantly higher in the lower quartiles (Q1 and Q2) than in the highest quartile (Q4) as the reference group (hazard ratios and 95% confidence intervals: Q1, 2.65 [1.69–4.25], Q2, 1.92 [1.27–2.94], and Q3, 1.31 [0.87–2.02]). The risk of heart disease was significantly higher in Q1 than in Q4 (hazard ratios and 95% confidence intervals: Q1, 1.64 [1.04–2.61], Q2, 1.34 [0.91–2.00], and Q3, 1.04 [0.71–1.52]). The risk of stroke was not associated with the modified Cr index. ConclusionsA lower modified Cr index is associated with an increased risk for heart disease and all-cause mortality, but not with the risk for stroke in patients on hemodialysis.