Influence of age, sex and potassium excretion on urinary prostaglandins in children.

Measurement of urinary 6-ketoprostaglandin (PG) F1 alpha and PGE2 excretion in 83 healthy children, aged 5-15 years, revealed that supervised 4 h urine collections under mild water diuresis provided more consistent results than overnight 12 h urine collections. Males had higher urinary excretion of 6-keto-PGF1 alpha but not of PGE2 compared with females. Urinary potassium was related to 6-keto-PGF1 alpha in both 4 and 12 h urine collections and urinary sodium to 6-keto-PGF1 alpha in 4 h collections only. In the sexes combined multiple regression analyses revealed age as the only significant influence on prostanoid excretion (P = 0.001). Thus age and sex and dietary potassium intake need to be considered in studies of urinary prostanoids in children.