Low protein nitrogen appearance as a surrogate of low dietary protein intake is associated with higher all-cause mortality in maintenance hemodialysis patients

J Nutr. 2013 Jul;143(7):1084-92. doi: 10.3945/jn.112.169722. Epub 2013 May 22.

Abstract

To determine the association between all-cause mortality and dietary protein intake in patients with chronic kidney disease, we performed a large-scale, 8-y prospective cohort study in 98,489 maintenance hemodialysis patients from a multicenter dialysis care provider. Compared with the reference level (60 to <70 g/d), low protein nitrogen appearance (PNA) levels [<30 g/d, HR: 1.40 (95% CI: 1.30, 1.50); 30 to <40 g/d, HR: 1.33 (95% CI: 1.28, 1.39)] was associated with higher all-cause mortality, and high PNA levels [≥110 g/d, HR: 0.92 (95% CI: 0.88, 0.97); 100 to <110 g/d, HR: 0.87 (95% CI: 0.82, 0.91)] were associated with lower all-cause mortality in all analyses. This association was also found in subanalyses performed among racial and hypoalbuminemic groups. Hence, using PNA as a surrogate for protein intake, a low daily dietary protein intake is associated with increased risk of death in all hemodialysis patients. Whether the association between dietary protein intake and survival is causal or a consequence of anorexia secondary to protein-energy-wasting/inflammation or other factors should be explored in interventional trials.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • Diet, Protein-Restricted*
  • Dietary Proteins / administration & dosage*
  • Female
  • Follow-Up Studies
  • Humans
  • Inflammation / pathology
  • Male
  • Middle Aged
  • Nitrogen / administration & dosage*
  • Proportional Hazards Models
  • Prospective Studies
  • Renal Dialysis / mortality*
  • Renal Insufficiency, Chronic / diet therapy
  • Renal Insufficiency, Chronic / mortality
  • Risk Factors

Substances

  • Biomarkers
  • Dietary Proteins
  • Nitrogen