Dehydration Status Aggravates Early Renal Impairment in Children: A Longitudinal Study

Nutrients. 2022 Jan 13;14(2):335. doi: 10.3390/nu14020335.


Dehydration is common in children for physiological and behavioral reasons. The objective of this study was to assess changes in hydration status and renal impairment across school weekdays. We conducted a longitudinal study of three repeated measures of urinalysis within one week in November 2019 in a child cohort in Beijing, China. We measured urine specific gravity (USG) to determine the dehydration status, and the concentration of β2-microglobulin (β2-MG) and microalbumin (MA) to assess renal function impairment among 1885 children with a mean age of 7.7 years old. The prevalence of dehydration was 61.9%, which was significantly higher in boys (64.3%). Using chi-square tests and linear mixed-effects regression models, we documented the trends of the renal indicators' change over time among different hydration statuses. Compared to Mondays, there were apparent increases of β2-MG concentrations on Wednesdays (β = 0.029, p < 0.001) and Fridays (β = 0.035, p < 0.001) in the dehydrated group, but not in the euhydrated group. As for the MA concentrations, only the decrease on Fridays (β = -1.822, p = 0.01) was significant in the euhydrated group. An increased trend of elevated β2-MG concentration was shown in both the euhydrated group (Z = -3.33, p < 0.001) and the dehydrated group (Z = -8.82, p < 0.001). By contrast, there was a decreased trend of elevated MA concentrations in the euhydrated group (Z = 3.59, p < 0.001) but not in the dehydrated group. A new indicator ratio, β2-MG/MA, validated the consistent trends of renal function impairment in children with dehydration. Renal impairment trends worsened as a function of school days during the week and the dehydration status aggravated renal impairment during childhood across school weekdays, especially tubular abnormalities in children.

Keywords: children; dehydration; renal impairment; weekly activity patterns.

MeSH terms

  • Beijing
  • Child
  • Dehydration / epidemiology*
  • Dehydration / physiopathology*
  • Dehydration / urine
  • Female
  • Humans
  • Kidney / physiopathology*
  • Longitudinal Studies
  • Male
  • Prevalence
  • Schools
  • Sex Factors
  • Urinalysis / methods