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Influence of upright activity on plasma renin activity and aldosterone concentration in children
J Fukushige1, K Shimomura, K Ueda
1Department of Paediatrics, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Insights
Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) decrease with age in children. Postural changes stimulate PRA and PAC, with greater PRA increases in older children, highlighting developmental changes in the renin-angiotensin-aldosterone system.
Area of Science:
- Pediatric Endocrinology
- Renal Physiology
- Cardiovascular Regulation
Background:
- The renin-angiotensin-aldosterone system (RAAS) plays a crucial role in blood pressure and electrolyte balance.
- Understanding RAAS development in infants and children is essential for diagnosing and managing related disorders.
Purpose of the Study:
- To investigate age-related changes in basal plasma renin activity (PRA) and plasma aldosterone concentration (PAC) in healthy children.
- To assess the impact of postural stimulation on PRA and PAC levels across different pediatric age groups.
- To determine factors influencing PRA and PAC levels, including sex, body composition, and electrolytes.
Main Methods:
- Measurement of PRA and PAC in 156 healthy infants and children under basal conditions (recumbency).
- Evaluation of PRA and PAC during and after postural change (standing).
- Analysis of correlations between RAAS parameters and various physiological and biochemical variables.
Main Results:
- Basal PRA significantly declined with increasing age.
- Postural change (standing) increased both PRA and PAC in all age groups.
- The increment in PRA was more pronounced in older children compared to younger ones.
- Neither basal nor stimulated PRA and PAC levels were affected by sex, body weight, body surface area, or electrolyte status.
- PRA and PAC returned to basal levels within 60 minutes of resuming recumbency.
Conclusions:
- Pediatric RAAS shows significant age-dependent changes, with decreasing basal PRA as children mature.
- The RAAS remains responsive to postural stimulation throughout childhood, with age-related differences in PRA response.
- Factors like sex, body size, and electrolytes do not significantly influence RAAS activity in healthy children under these conditions.
Abstract:
Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured in 156 healthy infants and children under basal conditions of normal diet and recumbency. PRA and PAC were also evaluated during and after stimulation of the renin-angiotension-aldosterone system by postural change. Basal values of PRA significantly declined with increasing age. Postural change by standing up resulted in an increase of PRA and PAC in all age groups. The increment of PRA but not of PAC was greater in older than in younger children. Neither the basal nor the stimulated levels of PRA and PAC were influenced by sex, body weight, body surface area, serum sodium, serum potassium, creatinine, and 24-h urine secretion of sodium and potassium. Both PRA and PAC returned to the basal levels within 60 min after resuming recumbent posture.