Dietary energy intake predicts mortality in Chinese patients with peritoneal dialysis: a single-center 18 years' follow-up study

Background Lower dietary energy intake (DEI) may be associated with increased mortality risk. This study aims to analyze the influence of baseline DEI, time average DEI, and other factors on survival in peritoneal dialysis (PD) patients. Method It was a single-center retrospective cohort study. Patients who started PD from January 2006 to June 2021 were included in this study and followed up until June 2023. Their baseline (six months after the beginning of PD) demographic, dietary intake, laboratory data, and time varying dietary intake data were collected and analyzed. The relationships between these data and survival were examined using Cox model to estimate death hazard ratios. Result A total of 794 patients were included in this study, 424 males and 370 females, with a mean age of 58.87 +/- 16.02 years. Their mean normalize baseline dietary energy intake (nDEI) was 25.46 +/- 6.72 kcal/kg/day, time average nDEI was 24.87 +/- 4.74 kcal/kg/day. The median follow-up duration was 46.58 (27.38, 78.52) months in the overall cohort. Based on multivariate Cox proportional hazard analysis, age (HR = 1.056, 95% Cl = 1.047-1.065, p < 0.001), diabetes (HR = 1.364, 95% Cl = 1.114-1.671, p = 0.003), serum albumin (HR = 0.945, 95% Cl = 0.923-0.967, p < 0.001), blood sodium (HR = 0.973, 95% Cl = 0.954-0.992, p = 0.002), serum urea (HR = 0.974, 95% Cl = 0.953-0.994, p = 0.025), and baseline nDEI (HR = 0.980, 95% Cl = 0.964-0.996, p = 0.017) were significantly associated with mortality. Baseline DPI, BMI and time average nDEI were not related to PD patients' survival. When classified baseline nDEI into 4 groups (< 25 kcal/kg/day, 25-29.99 kcal/kg/day, 30-34.99 kcal/kg/day, and >= 35 kcal/kg/day), the univariate and multivariate Cox proportional hazard analysis showed that the patients with nDEI 30-34.99 kcal/kg/day had the lowest mortality risk (using the DEI < 25 kcal/kg/day group as reference, p < 0.05). Conclusion Our study revealed that DEI 30-34.99 kcal/kg/day might be beneficial to the long-term outcome for the Chinese PD population.