Nyctohemeral rhythm of plasma renin activity and plasma aldosterone in children

Pediatr Res. 1982 May;16(5):354-6. doi: 10.1203/00006450-198205000-00007.


Circadian rhythms of plasma renin activity (PRA) and plasma aldosterone (PA) were studied in eight healthy children, 7 to 15 years old. Blood samples were obtained at 7:00 AM, 10:00 AM, 1:00 PM, 4:00 PM, 5:00 PM, 8.00 PM, and midnight on day 1 and 4:00 AM and 7:00 AM on day 2. Children had normal activity during this test. Intra- and interindividual changes were noted in PRA in plasma taken in the upright position. Mean PRA values for samples taken in the upright position were maximal at 1:00 PM (7 ng/ml/hr) and minimal at 5:00 PM (4.1 ng/ml/hr). Mean PRA in the supine position was maximal at 4:00 AM on day 2 (5.6 ng/ml/hr), and its rise was statistically significant compared with the mean PRA at 7:00 AM on the same day (3.9 ng/ml/hr). Plasma aldosterone varied without any definite pattern. No correlation was found between PRA and PA and 24-hr urinary sodium excretion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Aldosterone / blood*
  • Child
  • Circadian Rhythm*
  • Humans
  • Natriuresis
  • Posture
  • Renin / blood*
  • Renin-Angiotensin System*


  • Aldosterone
  • Renin