Purpose: Catecholamine release is a marker of stress, and high plasma norepinephrine levels have been associated with increased mortality. The predictive value of high urinary catecholamine excretion for functional decline and mortality in healthier older persons has not been determined.
Subjects and methods: We used data from the MacArthur Studies of Successful Aging to determine the effects of high urinary catecholamine excretion on 3- and 7-year mortality and functional decline. In 1988, 765 high-functioning older subjects provided complete overnight urine samples for norepinephrine and epinephrine, and 199 of these provided repeat samples in 1991. Subjects who were in the top tertile of urinary norepinephrine or epinephrine excretion in 1988 were considered high excreters; those in the top tertile in both 1988 and 1991 were considered sustained high excreters. We used bivariate and multivariate analysis to examine the relations between high catecholamine excretion and mortality and Rosow-Breslau functional decline in 1991 and 1995.
Results: In multivariate analyses, subjects with high baseline urinary excretion of epinephrine, norepinephrine, or either catecholamine were at higher risk for mortality and functional decline at 3 and 7 years, although the magnitude of risk (adjusted odds-ratios ranged from 1.1 to 3.1) varied depending upon specific catecholamine and outcome measure. Subjects who had sustained high urinary norepinephrine excretion were also at increased risk for 4-year mortality or functional decline.
Conclusions: High urinary catecholamine excretion in high-functioning, community-dwelling older persons likely reflects subclinical sympathetic stimulation and is a marker of increased risk for functional decline and mortality.