The Relationship Between Cardiovascular and Catecholamine Reactions to Laboratory and Real‐Life Stress

Studies on the predictive value of stress testing in the laboratory for the reaction to real‐life stress have shown equivocal results. The variety of laboratory tasks differ for unknown reasons in their predictive power, and the results vary unsystematically among the physiological parameters measured. Most studies have focused on the prediction of ambulatory levels of blood pressure. Many other influences, besides stress, however, influence ambulatory levels. Therefore, a better operationalization of real‐life stress is to measure a person in a resting position during a period of well defined real‐life stress. The present study investigates whether the difference in ability of laboratory stress tasks to predict real‐life stress values is due to the different type of physiological response they induce. Hence, in the present study a more detailed measurement of the stress response was performed. A second question was whether stress testing would add to the prediction of the real‐life stress reactions above the prediction based on resting levels. This question was answered for both cardiovascular and catecholamine reactions to laboratory tasks. Two active coping tasks, one inducing a mainly cardiac‐sympathetic reaction and the other a relatively more vascular response, and a cold pressor test were administered to 33 healthy young males. Real‐life stress consisted of the anticipation of the public defence of the PhD thesis. Tasks indeed differed in predictive power, but this was not a function of the type of response they induced. The heart rate responses to a reaction time task and the heart rate and diastolic blood pressure reaction to the cold pressor test added significantly to the prediction of real‐life blood pressure levels and responses above the prediction on the basis of pretask baselines. The data suggest that the predictive value of the heart rate and blood pressure response to the cold pressor for the real‐life blood pressure response is due to noradrenergic reactivity as the common mechanism. Because mental tasks were not superior to the cold pressor in predicting the response to real‐life stress, it is concluded that it does not matter what kind of laboratory stressor is used for this purpose, as long as it adequately triggers a common physiological mechanism. The urine‐catecholamine reaction to the series of tasks was unrelated to the rise in catecholamines due to the real‐life stressor.