[Excretion of free catecholamines in relation to age, sex and blood pressure]

The influence of age, sex and hypertension on urinary excretion of free catecholamines was evaluated in 190 men (64 hypertensive patients) and 75 women (10 hypertensive patients). Noradrenaline correlates positively with age in healthy men (r = 0.37, p less than 0.001) and women (r = 0.36, p less than 0.001). Adrenaline and dopamine do not show any significant correlation with age. Noradrenaline excretion is slightly higher in young (less than or equal to 39 years of age) and significantly higher in old (greater than or equal to 40 years of age) hypertensive patients than in age-matched control subjects. Noradrenaline (32 +/- 15 micrograms X 24 h-1) and adrenaline excretion (9 +/- 7 micrograms X 24 h-1) are lower in the group of younger women than in younger men (52 +/- 23 and 19 +/- 12 micrograms X 24 h-1). We assume that the lower excretion of free catecholamines in younger women is significant for a lower sympathetic activity.