Interdialytic Weight Gain, Mortality Linked
The investigators, who noted that HD patients and heart failure patients are similar in that both populations retain fluid frequently and have excessively high mortality, studied two-year mortality among 34,107 HD patients across the United States who had an average weight gain of at least 0.5 kg above their end-dialysis dry weight by the time subsequent HD treatment started.
Kamyar Kalantar-Zadeh, MD, MPH, PhD, of the Harold Simmons Center for Kidney Disease Research and Epidemiology at the University of California at Los Angeles, and his collaborators found that 86% of patients had an interdialytic weight gain of more than 1.5 kg.
Compared with patients who had an interdialytic weight gain of 1.5-2.0 kg, those who had a 4.0-kg or more weight gain had a 25% increased risk of cardiovascular death and a 28% increased risk of death from any cause, after adjusting for case mix and surrogates of malnutrition-inflammation complex. Subjects whose weight gain was below 1.0 kg had a 33% and 26% decreased risk of cardiovascular and all-cause mortality, respectively. The authors reported their findings in Circulation (2009;119:671-679).“Given the striking similarities between individuals with chronic heart failure and those with advanced CKD undergoing long-term dialysis treatment, the mechanisms by which fluid retention influences survival in dialysis patients may be similar to those that occur in heart failure patients,” the investigators concluded.