Resting venous plasma adrenalin in 70-year-old men correlated positively to survival in a population study: the significance of the physical working capacity.

Abstract

OBJECTIVE: The aim of the study was to evaluate plasma noradrenaline (NA) and plasma adrenalin (A) as predictors of mortality in a population study. SUBJECTS: All subjects were 70 years of age in 1984. They were selected from the National Person Register. Altogether, 804 subjects participated in a comprehensive medical examination. INTERVENTIONS: Plasma NA and A were measured in blood samples collected after the subjects had rested in the supine position for 15 min. The subjects have now been followed for 7 years. MAIN OUTCOME MEASURES: Seven years later, 115 men and 63 women had died. RESULTS: Cox regression analysis showed that the mortality in the male group was positively correlated to plasma NA (P < 0.002) and inversely correlated to forced vital capacity (P < 0.0000) and plasma A (P < 0.02). A positive correlation was obtained between physical working capacity and plasma A. When an index of physical working capacity was included in the Cox regression analysis, both plasma NA and plasma A became insignificant, whereas a strong positive correlation appeared between physical working capacity and survival (P < 0.0000). Those who had low plasma A values in 1984 tended to die from cardiovascular diseases in the follow-up period, whereas in those who died from cancer, plasma A values were similar to those of the general population. CONCLUSIONS: Subjects with high plasma A values had the best survival rate during the 7 year follow-up period, probably because they also had the best physical working capacity. High plasma NA values, as expected, were associated with a reduced survival rate. Measurements of physical working capacity may be an inexpensive measure of probable survival in 70-year-old subjects.