Influence of physiological factors on the age-related increase in blood pressure in healthy men.
The independent and collective influences of several physiological factors on the age-related increase in blood pressure in healthy men were examined. Twenty-seven younger and 25 older, mostly normotensive, healthy men were studied. Blood pressure, body fat, body fat distribution, maximal oxygen consumption (VO2max), plasma norepinephrine, dietary Na, and erythrocyte Na-K pump activity were measured. Older men showed 57% higher percent body fat, 40% higher plasma norepinephrine concentration, 14% greater mean arterial blood pressure (MAP), and 5% higher plasma K concentration than younger men (all p < 0.01). Older men showed a 38% (p < 0.01) lower VO2max, 19% (p < 0.05) lower energy intake, 18% (p < 0.05) lower Na-K pump rate constant, and a 17% (p < 0.05) lower Na-K pump rate. Group means for MAP were adjusted for combinations of plasma norepinephrine, waist:thigh ratio, VO2max, and the Na-K pump rate constant, to determine if any one variable or combination could account for the age related increase in MAP. Statistical adjustment for plasma norepinephrine, waist:thigh ratio, and Na-K pump rate constant eliminated the significant difference between MAPs for the two groups. Thus, alterations in sympathetic nervous system activity, body fat distribution, and the membrane Na-K pump activity independently contribute to the age-related increase in MAP in healthy men.
Webb
G D
GD
Department of Molecular Physiology and Biophysics, University of Vermont College of Medicine, Burlington 05401, USA.
Toth
M J
MJ
Poehlman
E T
ET
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001794:Blood Pressure; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D000254:Sodium-Potassium-Exchanging ATPase
D000254:Sodium-Potassium-Exchanging ATPase