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Urinary sodium to creatinine ratio in healthy infants

Michelle Mann1, Wayne Waz, James Poupoulos

  • 1Baylor College of Medicine, Houston, TX 77030, USA. mcmann@texaschildrenshospital.org

Clinical Pediatrics
|June 22, 2012
PubMed

Insights

The urinary sodium to creatinine ratio (UNa:UCr) in healthy infants was established at 11.73. This finding suggests appropriate sodium regulation in infants, even with lower intake levels.

Area of Science:

  • Pediatric Nephrology
  • Infant Nutrition
  • Clinical Chemistry

Background:

  • Sodium is vital for infant growth, with recommended daily intake of 2-3 mmol/kg/d.
  • Establishing reference ranges for urinary sodium is crucial for assessing hydration and electrolyte balance in infants.

Purpose of the Study:

  • To determine the reference range for the urinary sodium to creatinine ratio (UNa:UCr) in healthy infants.
  • To provide a benchmark for evaluating sodium status in pediatric populations.

Main Methods:

  • Measurement of urinary sodium (UNa) and urinary creatinine (UCr) in a cohort of healthy infants.
  • Calculation of the UNa:UCr ratio and estimation of daily sodium intake via parental reports.
  • Statistical analysis to establish reference ranges and assess correlations.

Main Results:

  • The mean UNa:UCr in 71 healthy infants was 11.73 (95% CI = 10.24-13.23).
  • Mean estimated daily sodium intake was 1.34 mEq/kg/d, falling below recommended levels.
  • No significant correlation was observed between sodium intake and UNa:UCr, or significant differences across age groups.

Conclusions:

  • The established UNa:UCr reference range of 11.73 is a key finding for healthy infants.
  • This ratio likely indicates appropriate physiological adaptation to sodium intake in infants.
  • The results suggest that infants in the study maintained sodium homeostasis despite consuming sodium at the lower end of recommended intake.

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