Magnitude of end-dialysis overweight is associated with all-cause and cardiovascular mortality: a 3-year prospective study.

ABSTRACT

BACKGROUND: We hypothesized that the difference between the prescribed end-dialysis body weight, defined end-dialysis over-weight (edOW; kg), and the body weight which is actually attained could impact survival in hemodialysis (HD) patients. The aim of this prospective observational study was to evaluate if edOW could influence survival in a cohort of prevalent HD patients, controlled for multiple dialysis and clinical risk factors and followed for 3 years. METHODS: One hundred and eighty-two patients (117 men, age 65 ± 13 years) on regular HD treatment for at least 6 months [median 48 months (range 6-366)] were followed from January 1, 2008 to December 31, 2010. Eighty-four patients (46%) did not achieve their prescribed dry body weight (dBW); their median edOW was 0.4 kg (range 0.1-1.4). Ninety-eight died during observation, mainly from cardiovascular reasons (69%). Multivariate Cox regression analysis was utilized to evaluate the effect edOW, ultrafiltration rate (UFR), interdialytic weight gain (IDWG), age, sex, dialytic vintage, cardiovascular disease, antihypertensive therapy, diabetes, duration of HD, dBW, BMI, mean arterial blood pressure, Kt/V, and protein catabolic rate (PCRn) had on mortality. RESULTS: Age (HR 1.04; CI 1.03-1.05; p <0.0001), IDWG (HR 2.62; CI 2.06-3.34; p < 0.01), UFR (HR 1.13; CI 1.09-1.16; p< 0.01), PCRn (HR 0.02; CI 0.01-0.04; p <0.001), and edOW (HR 2.71; CI 1.95-3.75; p < 0.02) were independently correlated to survival. The relative receiver operating characteristic curve identified a cutoff value of 0.3 kg for edOW in predicting death. CONCLUSIONS: High edOW is independently associated with an increased long-term risk of all-cause and cardiovascular mortality in HD patients. Better survival was observed in patients with edOW <0.3 kg. For patients with higher edOW, longer or more frequent dialysis sessions should be considered in order to prevent the deleterious consequences of excessive body fluid expansion.