Inflammation and dietary protein intake exert competing effects on serum albumin and creatinine in hemodialysis patients

Kidney Int. 2001 Jul;60(1):333-40. doi: 10.1046/j.1523-1755.2001.00804.x.

Abstract

Background: Cross-sectional studies have shown an inverse correlation between serum C-reactive protein (CRP) and serum albumin concentration in hemodialysis patients. The net effects of inflammation and dietary protein intake on nutritional markers over time are unknown.

Methods: To explore the effects of CRP and normalized protein catabolic rate (nPCR) on serum albumin and creatinine, we analyzed six consecutive months of laboratory data from 364 hemodialysis patients, using a multivariable Mixed model with conservative biases.

Results: The overall trend over time in serum albumin was slightly positive (0.039 g/dL/month) and in serum creatinine slightly negative (-0.052 mg/dL/month). With increasing CRP, serum albumin declined significantly (-0.124 g/dL/month per unit increase in log CRP, adjusted for age, gender, race, diabetes, and nPCR, P < 0.0001). Serum albumin increased with increasing nPCR (0.021 g/dL/month per 0.1 g/kg/day, P < 0.0001). The effect of CRP on albumin was attenuated in African Americans and at a higher nPCR. Corresponding values for creatinine mirrored those for albumin. With increasing CRP, creatinine declined significantly [-0.142 mg/dL/month per unit increase in log CRP, adjusted for age, gender, race, diabetes (time since initiation of dialysis; vintage), Kt/V, and nPCR, P = 0.002]. Serum creatinine increased with increasing nPCR (0.183 mg/dL/month per g/kg/day, P < 0.0001).

Conclusions: Proxies of inflammation and dietary protein intake exert competing effects on serum albumin and creatinine in hemodialysis patients. These data provide a rationale for prospective testing of dietary protein supplementation in hemodialysis patients with biochemical evidence of ongoing inflammation and "malnutrition."

MeSH terms

  • Adult
  • Aged
  • C-Reactive Protein / metabolism
  • Cohort Studies
  • Creatinine / blood*
  • Cross-Sectional Studies
  • Dietary Proteins / pharmacology*
  • Female
  • Hospitalization
  • Humans
  • Inflammation / blood*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Models, Biological
  • Mortality
  • Prognosis
  • Proteins / metabolism
  • Renal Dialysis*
  • Serum Albumin / analysis*

Substances

  • Dietary Proteins
  • Proteins
  • Serum Albumin
  • C-Reactive Protein
  • Creatinine