Predictors of Survival in Chronic Hemodialysis Patients: A 10-Year Longitudinal Follow-Up Analysis

Abstract

<b><i>Background:</i></b> Risk factors of mortality in chronic hemodialysis patients have not yet been sufficiently evaluated. In particular, chronological transits and interactions of the impact of risk factors have rarely been described. <b><i>Methods:</i></b> This study is a post hoc analysis of the participants in the Olme­sartan Clinical Trial in Okinawan Patients under OKIDS (OCTOPUS) study conducted between June 2006 and June 2011. We additionally followed up on the prognosis of the participants until July 31, 2018. Standardized univariable and multivariable Cox regression analyses were used to evaluate the influences of the participants’ baseline characteristics on all-cause mortality. We also evaluated chronological changes in the impacts of risk factors, interactions among predictors, and the influence of missing values using sensitivity analyses. <b><i>Results:</i></b> Of the 469 original trial participants, 461 participants were evaluated. The median time of follow-up was 10.2 years. A total of 211 (45.8%) participants were deceased. The leading causes of death were infection (<i>n</i> = 72, 34.1%) and cardiovascular disease (<i>n</i> = 66, 31.3%). Univariate and multivariate Cox regression analyses revealed that the impact of diabetes mellitus, history of coronary intervention, and hypoalbuminemia were significant risk factors for mortality during the whole follow-up period. During the early follow-up period (≤3 years), standardized univariate Cox regression analyses revealed that history of amputation (hazard ratio [HR] = 4.61, <i>p</i> < 0.001), lower dry weight, higher cardiothoracic ratio, and lower potassium levels were statistically significant risks. In those who survived for longer than 3 years, a history of stroke (HR = 1.73, <i>p =</i> 0.006), higher systolic blood pressure, lower serum sodium levels, and higher levels of hemoglobin, and serum phosphate were significant risks. We also observed a stable interaction between the impacts of serum phosphate and albumin on all-cause mortality. <b><i>Conclusion:</i></b> In chronic hemodialysis patients, targets to improve the short-term prognosis and long-term prognosis are not equivalent. Hyperphosphatemia was a significant risk factor for the all-cause mortality among patients with normal serum albumin levels but not among patients with compromised albumin levels.

Nutrition and quality of life in chronic kidney disease patients: a practical approach for salt restriction

“…When we extended the observation period of the previous RCT study participants to 10 years [66] and investigated the combination of S-Alb and serum phosphate (S-Pi) on survival, we found that the best survival was seen in those patients with higher S-Alb and lower S-Pi, while the worst survival was seen in those patients with lower S-Alb and lower S-Pi. In chronic HD patients, S-Pi appears to be a surrogate of protein intake [67].…”

“…In a recent study of 461 chronic HD patients with a median follow-up of 10 years, 46% of patients died [67]. The main causes of death were infection (34%) and cardiovascular disease (31%).…”

Long-term Weight Loss as a Predictor of Mortality in Hemodialysis Patients

“…1 Although the discrepancy was observed in relatively non-obese HD participants of our study, the means of baseline BMI at the enrolment were 23.0±3.7 in deceased patients and 22.7±3.4 in survived patients, respectively. 8 Further, comprehensive baseline data and a high follow-up rate (98.3%) allowed us to observe less biased associations.…”

“…In the study cohort, 5% of patients died every year. 8 Therefore, a 3-year follow-up period would have reduced the sample size by 15% or increased the amount of missing data, both of which would affect the study's statistical power and introduce a selection bias. Additionally, a 1-year timeframe cannot distinguish between long-term BW change and acute BW change caused by haemodynamic change or infectious diseases; thus, our analysis excluded BW changes within 1 year.…”

“…Our previous study showed that a higher baseline BW was associated with lower mortality during the initial 3 years of follow-up, whereas it was associated with higher mortality between 3 and 10 years of follow-up. 8 The opposite relationship between BW and mortality before and after three years implied that long-term change of BW in addition to baseline BW may affect mortality.…”