Circadian rhythms in blood, urine and gastric acid secretion of presumably healthy volunteers.

The mean conisor technique reveals statistically significant circadian rhythms for serum concentrations of iron, chloride, cortisol, PBI, the fibrinolytic activity of blood, urinary iron excretion and gastric acid secretion in studies covering a 24-h span for presumably healthy subjects. Quantification of these rhythms provides internationally comparable reference values both for the conventional clinical laboratory and for any special chronobiologic applications.