Investigation of normalized protein catabolic rate as a marker of nutritional status in infants and children receiving chronic hemodialysis: a longitudinal cohort study.

Background: Children with kidney failure are at risk for compromised nutritional status due to a variety of challenges. Normalized protein catabolic rate (NPCR) below 1 g/kg/day has been associated with weight loss in adolescent patients on chronic hemodialysis. We sought to establish NPCR as a marker of nutritional status in patients on hemodialysis under age 13 years.

Methods: A longitudinal retrospective cohort study was conducted to investigate NPCR as a marker of a composite indicator of compromised nutritional status (MINI) in infants and children (0-12 years old) who received chronic hemodialysis between 2002 and 2023. Generalized linear mixed effect models were applied to explore associations between MINI and NPCR across the study cohort (0-12 years) and after age stratification (0-3 years and 4-12 years).

Results: The analysis included 758 observations of 58 patients with median age 8 (IQR 3,11) years. Compromised nutritional status was identified in 35/58 patients at 235/758 time points according to the composite definition of MINI. In children 0-12 years, NPCR < 1.2 was associated with approximately twofold increased odds of MINI (p = 0.04), adjusted for time on dialysis and Kt/V. After stratifying by age, children ages 4-12 years with NPCR < 1.2 had approximately fourfold higher odds of MINI (p = 0.003).

Conclusions: NPCR < 1.2 g/kg/d was associated with a composite indicator of compromised nutritional status in this single-center retrospective analysis of the largest sample of hemodialysis patients under the age 13 to date. Multicenter studies are needed to verify these findings.