July 1, 1997Open Access
View Full PaperA Low Sympathoadrenal Activity is Associated with Body Weight Gain and Development of Central Adiposity in Pima Indian Men
Key Result
Lower baseline urinary norepinephrine excretion was associated with greater body weight gain (r = -0.38; p = 0.009), and lower epinephrine excretion with central adiposity (r = -0.44; p = 0.003).
Study Design
Type
Cohort (n=64)
Structured PICO
Is low sympathoadrenal activity associated with body weight gain and development of central adiposity in Pima Indian men?
P
Population
64 Pima Indian men (mean age 28 years) evaluated for baseline sympathoadrenal function, with 44 followed for a mean of 3.3 years to assess body weight gain and central adiposity.
E
Exposure
Baseline sympathoadrenal function estimated by 24-hour urinary norepinephrine (NE) and epinephrine (Epi) excretion rates
O
Outcome
Body weight gain and changes in body fat distribution (waist-to-thigh circumference ratio)surrogate
Low sympathetic nervous system activity and low adrenal medulla activity are associated with body weight gain and the development of central adiposity, respectively.
Main Result
Effect estimate: r = -0.38
p-value: p=0.009
Abstract
To investigate the possible role of impaired sympathetic nervous system and/or adrenal medullary function in the etiology of human obesity, we studied 64 Pima Indian men (28 +/- 6 years, 101 +/- 25 kg, 34 +/- 9% body fat, mean +/- SD) in whom sympathoadrenal function was estimated at baseline by measurements of 24-hour urinary norepinephrine (NE) and epinephrine (Epi) excretion rates under weight-maintenance conditions. Body weight, body composition (hydrodensitometry), and body fat distribution (waist-to-thigh circumference ratio, W/T) were measured at baseline and follow-up. Follow-up data were available on 44 subjects who gained on average 8.4 +/- 9.5 kg over 3.3 +/- 2.1 years. In these subjects, baseline NE excretion rate, adjusted for its determinants (i.e., fat free mass, fat mass, and W/T), correlated negatively with bodyweight gain (r = -0.38; p = 0.009). Baseline Epi excretion rate correlated negatively with changes in W/T (r = -0.44; p = 0.003). In conclusion, our data show for the first time that a flow sympathetic nervous system activity is associated with body weight gain in humans. Also, a low activity of the adrenal medulla is associated with the development of central adiposity.