Plasma aldosterone levels in the 1st week of life in infants of less than 30 weeks gestation

Bourchier, D

doi:10.1007/s00431-004-1572-0

Cited by 25 publications

(23 citation statements)

References 22 publications

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“…As one of the direct applications of this study, we propose that urinary aldosterone measurement is the best index for accurate evaluation of the mineralocorticoid effector mechanisms. Plasma aldosterone does not constitute a good parameter at birth in accordance with previous studies, which already reported the lack of correlation between kalemia and plasma aldosterone concentrations (37,38). Instead, the highly significant negative relationship found between urinary aldosterone and plasma potassium concentrations establishes that aldosterone participates to the control of potassium balance.…”

Section: Discussionsupporting

confidence: 83%

Physiological Partial Aldosterone Resistance in Human Newborns

Martinerie

Pussard

L’Hélias³

et al. 2009

Pediatr Res

104

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ABSTRACT:In the neonatal period, the human kidney is characterized by an impaired ability to regulate water and sodium homeostasis, resembling partial aldosterone resistance. The aim of our study was to assess this hormonal insensitivity in newborn infants and to determine its relationship with neonatal sodium handling. We conducted a prospective study in 48 healthy newborns and their mothers. Aldosterone, renin, and electrolyte concentrations were measured in umbilical cords and in maternal plasma. Urinary aldosterone concentrations and sodium excretion were determined at urination within 24 h after birth. A significant difference was observed between aldosterone and renin levels in newborn infants compared with their mothers (817 Ϯ 73 versus 575 Ϯ 55 pg/mL and 79 Ϯ 10 versus 15 Ϯ 2 pg/mL, respectively, p Ͻ 0.001). This hyperactivation of the renin-angiotensin-aldosterone system was associated with hyponatremia and hyperkalemia in the newborn infants, and high urinary sodium loss, consistent with a partial aldosterone resistance at birth. Unlike plasma aldosterone, urinary aldosterone concentration was found highly correlated with plasma potassium concentrations, thus representing the best index for accurate evaluation of mineralocorticoid sensitivity. Our study represents a comprehensive characterization of the renin-aldosterone axis in newborn infants and provides evidence for physiologic partial aldosterone resistance in the neonatal period. (Pediatr Res 66: 323-328, 2009) T he human kidney displays a tubular immaturity at birth, with sodium waste, responsible for a negative sodium balance, and an impaired ability to reabsorb water (1), which is aggravated under circumstances such as prematurity, pyelonephritis, and gastroenteritis (2). This inability to maintain homeostatic functions is a major problem encountered by pediatricians, most notably in preterm infants. Indeed, the challenge is to find a balance between the lethal risk of dehydration and the associated morbidity of excessive hydromineral supplementation, contributing to severe complications such as intraventricular hemorrhage and bronchopulmonary dysplasia (3). A better understanding of water and sodium regulation in the neonatal period is a prerequisite to propose new therapeutic strategies for the management of preterm infants.Sodium reabsorption is mainly controlled by aldosterone, a steroid hormone synthesized in the zona glomerulosa of the adrenal gland, secondary to renin stimulation via angiotensin II and to potassium stimulation (4). In the distal nephron, aldosterone, by binding to its receptor, the mineralocorticoid receptor, a transcription factor (5), tightly regulates the expression and the activity of several transport proteins implicated in sodium, potassium, and water homeostasis, as the alpha subunit of the epithelial sodium channel (6), the Na-KATPase (7), and the aquaporin 2 (8). A possible role of a partial and transient tubular unresponsiveness to this hormone has been suggested to account for sodium waste in neonates (9,10)....

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Section: Discussionsupporting

confidence: 83%

Physiological Partial Aldosterone Resistance in Human Newborns

Martinerie

Pussard

L’Hélias³

et al. 2009

Pediatr Res

104

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“…18 We found a negative correlation between plasma sodium and UAE already during the first three days of life that may confirm the physiological partial aldosterone resistance in human neonates, due to a progressive increase of renal mineralocorticoid receptor expression level in the first days after birth, concurrently with renal maturation. 23,24 In the exploratory analysis we found a significant positive correlation between UAE and gestational age and birth …”

Section: Discussionsupporting

confidence: 75%

“…3,4,10 While clear reference values for aldosterone exist for paediatric populations, few and heterogeneous data are available for term and preterm neonates. [11][12][13][14][15][16][17][18] The studies carried out during the neonatal period varied in the timing of sampling and almost all determined aldosterone plasma level.…”

Section: Discussionmentioning

confidence: 99%

Early urinary aldosterone excretion in very low birth weight infants

Costa

Cota

Romagnoli

et al. 2012

J Renin Angiotensin Aldosterone Syst

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Hypothesis/Introduction: In the neonatal period, many factors may interfere with aldosterone production but data currently available are few and controversial. In this study we aim to assess the early urinary aldosterone excretion (UAE) in very low birth weight (VLBW) infants and to identify some possible clinical and biochemical variables that may influence this excretion. Materials and methods:We conducted a prospective study in 30 VLBW infants. Aldosterone was measured in the first 72 hours of life in the urine and plasma and urinary electrolytes were determined. Demographic and clinical data were also recorded.Results: The exploratory analysis showed that a significant positive correlation exists between UAE and gestational age and birth weight and that infants with respiratory distress syndrome have higher urinary aldosterone levels than infants without respiratory distress, but only plasma sodium resulted a significant independent factor that negatively influenced UAE at linear regression analysis (coefficient -0.02, 95% confidence interval [-0.03; -0.004]; adjusted R 2 0.33). Conclusions:The renin-angiotensin-aldosterone system of VLBW infants seems to be able, even immediately after birth, to respond to variations of plasma sodium concentrations; measurement of UAE constitutes an interesting method to determine aldosterone production, avoiding blood sampling in neonates so small and frail as VLBW infants.

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“…These conditions appear to result from an impaired capacity to regulate water and sodium homeostasis, mimicking partial aldosterone resistance (Martinerie et al, 2009a). Previous studies proposed that the reduced kidney responsiveness to aldosterone could be related to low mineralocorticoid receptor (MR) expression during human development, as demonstrated by the lack of detectable MR immunoreactivity in the renal cortical collecting duct during the late gestational age and neonatal periods, contrasting to the high aldosterone levels (Bourchier, 2004;Martinerie et al, 2009b). Our results indicate that neonate salt wasting syndrome could also be the consequence of a primary defect in aldosterone secretion in preterm infants, as suggested by low level of adrenal CYP11B2 expression before 28 WG.…”

Section: Discussionmentioning

confidence: 94%