Association between cold dialysis and cardiovascular survival in hemodialysis patients

Background. Higher cardiovascular mortality has been noted in patients with chronic kidney disease (CKD). CKD patients are also known to have impaired energy expenditure but the role of energy expenditure in cardiovascular disease is not yet known. Furthermore, the association between cold dialysis (CD) and clinical outcomes in hemodialysis patients is unclear. Methods. This was a single-center retrospective cohort study consisting of two groups: a CD group with dialyzate temperature <35.5 degrees C and a standard dialysis (SD) group with dialyzate temperature between 35.5 and 37 degrees C. The end points of the study were overall mortality, cardiac mortality and non-cardiac mortality. The study analyzed the associations between dialyzate temperature and long-term survival in CD and SD groups. Propensity score analysis was used to control for intergroup baseline differences. Results. Baseline characteristics of both groups were similar. Kaplan-Meier analysis showed that CD was significantly associated with a lower risk for overall mortality (P = 0.006) and cardiac mortality (P = 0.023) but not for non-cardiac mortality or infectious mortality. After multi-variate Cox regression analysis, adjusting for propensity scores and other possible confounding factors, CD remained a significant beneficial factor for overall mortality (P = 0.030) and cardiac mortality (P = 0.034). Conclusion. Our studies show that CD is significantly and independently associated with a lower risk for overall mortality and cardiac mortality.