Urinary retinol excretion and kidney function in children with shigellosis

Am J Clin Nutr. 1998 Nov;68(5):1095-103. doi: 10.1093/ajcn/68.5.1095.

Abstract

Background: Acute infections, including diarrhea, are associated with an increased risk of vitamin A deficiency. Urinary retinol excretion during such infections may contribute to this risk. The mechanism accounting for urinary retinol loss has not been clearly defined.

Objective: This study attempted to determine whether urinary retinol loss in children with acute infection is associated with impaired kidney function, particularly impaired tubular protein reabsorption.

Design: Urinary retinol excretion and kidney function were examined in 66 hospitalized children 5 mo to 5 y of age with acute Shigella dysentery.

Results: Urinary retinol loss occurred in 59% of children and was substantial (>0.1 micromol/d) in 8% of them. Children with more severe disease excreted higher concentrations of urinary retinol; those with a body temperature > or =40 degrees C excreted a mean of 0.10 +/- 0.18 micromol/d compared with 0.005 +/- 0.008 micromol/d for other children (P < 0.0001). Children with more severe disease also had impaired tubular reabsorption of low-molecular-weight proteins beta2-microglobulin and retinol binding protein (RBP)], although other measures of tubular and glomerular function were not similarly impaired. In multiple regression analysis, severity of disease indicators were the best predictors of tubular reabsorption of beta2-microglobulin (R2 = 0.53) whereas tubular reabsorption of beta2-microglobulin and RBP were found to be the best predictors of urinary retinol loss (R2 = 0.69).

Conclusions: A significant amount of retinol was excreted in the urine in children with shigellosis: 8% excreted >0.10 micromol/d (15% of the daily metabolic requirement). Impaired tubular reabsorption of low-molecular-weight proteins, such as RBP transporting retinol, appeared to be the cause of this urinary retinol loss.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • C-Reactive Protein / metabolism
  • Child, Preschool
  • Cohort Studies
  • Dysentery, Bacillary / blood
  • Dysentery, Bacillary / metabolism
  • Dysentery, Bacillary / urine*
  • Glomerular Filtration Rate
  • Humans
  • Infant
  • Kidney / metabolism*
  • Kidney / physiology
  • Male
  • Nutrition Disorders / metabolism
  • Nutrition Disorders / urine
  • Nutritional Status
  • Orosomucoid / metabolism
  • Regression Analysis
  • Retinol-Binding Proteins / metabolism
  • Severity of Illness Index
  • Shigella / isolation & purification
  • Vitamin A / blood
  • Vitamin A / urine*

Substances

  • Orosomucoid
  • Retinol-Binding Proteins
  • Vitamin A
  • C-Reactive Protein