80-year-old men have elevated plasma concentrations of catecholamines but decreased plasma renin activity and...

Plasma concentrations of adrenaline, noradrenaline, aldosterone and plasma renin activity were determined in a selected group of 80-year-old men (N = 41) in good health without clinical signs of cardiovascular disease, and were compared to levels in young healthy males (N = 20, 24-28 years). Plasma adrenaline and noradrenaline concentrations were higher (0.24 median; 25th-75th percentiles 0.16-0.34 nmol/L vs 0.15; 0.11-0.18 nmol/L, p < 0.01 and 2.22; 1.58-3.27 nmol/L vs 1.15; 1.00-1.74 nmol/L, p < 0.001), and plasma renin activity and plasma aldosterone concentration were lower in the old than in the young men (0.65; 0.35-1.04 micrograms/L/1h vs 2.09; 1.23-2.41 micrograms/L/1h, p < 0.001 and 0.12; 0.09-0.19 nmol/L vs 0.38; 0.28-0.54 nmol/L, p < 0.001). In conclusion, increased plasma concentrations of catecholamines and decreased plasma concentration of aldosterone and plasma renin activity in old men, as compared to young men, must be considered when interpreting data of these hormones in elderly men.