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The renin-angiotensin-aldosterone system in infancy and childhood in basal conditions and after stimulation

T Fiselier, L Monnens, P van Munster

    European Journal of Pediatrics
    |November 1, 1984
    PubMed

    Insights

    This study found that plasma renin activity and aldosterone levels decrease with age in children. The renin-angiotensin-aldosterone system shows different responses to salt restriction and posture changes in infants versus older children.

    Area of Science:

    • Pediatric Endocrinology
    • Renal Physiology
    • Cardiovascular Regulation

    Background:

    • The renin-angiotensin-aldosterone system (RAAS) plays a crucial role in regulating blood pressure and electrolyte balance.
    • Understanding RAAS development and response in children is vital for diagnosing and managing related disorders.

    Purpose of the Study:

    • To characterize basal and stimulated RAAS activity in healthy infants and children.
    • To investigate age-related changes in plasma renin activity (PRA), aldosterone (PA), and urinary aldosterone (UAldo).
    • To assess the impact of sodium restriction and postural changes on RAAS components in different pediatric age groups.

    Main Methods:

    • Measurement of PRA, PA, and electrolytes (sodium, potassium) in plasma and urine from 107 healthy children.
    • RAAS stimulation through 4-day sodium restriction followed by postural change in a subset of 40 children.
    • Statistical analysis to determine age-related trends and correlations.

    Main Results:

    • Significant age-related decreases in PRA, PA, and UAldo were observed (P < 0.001), with high variability in infants.
    • Sodium restriction increased PRA and UAldo, but PA response was blunted in infants (0-6 months).
    • Postural changes had a more pronounced effect on RAAS in older children compared to younger ones.

    Conclusions:

    • The RAAS undergoes significant developmental changes throughout childhood, with distinct responses to stimuli in early infancy.
    • These findings provide normative data for basal and stimulated RAAS function, aiding in the study of pediatric salt-wasting conditions and hypertension.

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