Consistency in catecholamine excretion in laboratory and natural settings: correlational and variance components analyses

Data from 20 healthy male subjects were used to evaluate the consistency in catecholamine excretion in both laboratory and natural situations during approximately a 48-hr period. Correlational analyses showed high interindividual consistency in adrenaline excretion under laboratory conditions regardless of degree and kind of activity and of the interval at which measures were taken. In non-standardized natural situations the consistency was low. For nor adrenaline the pattern was less regular. Analysis of variance components showed that absolute consistency was high in both amines in situations with similar activity content and low activity level. It was found that the more similar the situations the more of variation in catecholamine excretion was due to interindividual differences and the more dissimilar the situations the more of the variation was due to interaction. It is concluded that the degree of consistency in catecholamine excretion varies with situational characteristics.