Purpose: Initial or single time point serum albumin levels have been shown to be important in predicting the prognosis of peritoneal dialysis (PD) patients. However, we assume the dynamic change and trend of albumin after PD are essential. We aimed to investigate the association between baseline albumin levels, albumin trajectories, and patient mortality in a retrospective cohort study.
Methods: In this retrospective cohort study, 547 incident PD patients were enrolled from Peking University Third Hospital. Date were collected by medical records review, including age, gender, body mass index, primary disease, comorbidities, and laboratory tests. A joint model for longitudinal data and time-to-event data was used to establish the relationship between serum albumin trajectories and mortality risk of PD patients.
Results: The albumin trajectories was negatively correlated with risk of death. The increase in the current value of albumin trajectories at time points t after PD was associated with decreased risk of death (HR = 0.881, p < 0.0001). There was no statistical association between initial albumin and risk of death (HR = 1.030, 95% CI 0. 995-1.066). The results showed that increased age, higher albumin-corrected Ca levels, and higher eGFR values were risk factors for death. In addition, predictors of low albumin levels are increased PD time, increased age, increased albumin-corrected Ca, and decreased BMI as well as initial albumin levels.
Conclusion: This study demonstrates that albumin trajectories after PD is better than initial serum albumin level in predicting mortality risk. Increasing albumin level over time can improve the prognosis of PD patients.
Keywords: Albumin; Joint model; Mortality; Peritoneal dialysis.