Habitual Exercise and Arterial Aging
Douglas R. Seals
University of Colorado
The risk of
cardiovascular diseases (CVD) increases with age. This is due primarily to development of
arterial dysfunction and disease, including increases in large elastic artery
stiffness and impairment of vascular endothelial function. Habitual aerobic exercise is associated
with reduced risk of CVD in middle-aged and older adults. Compared with their sedentary peers, men
who regularly perform strenuous aerobic exercise demonstrate smaller increases
in large elastic artery stiffness and largely preserved vascular endothelial
function with aging. Regular
moderate-intensity aerobic exercise reduces large elastic artery stiffness and
improves/restores vascular endothelial function in previously sedentary
middle-aged and older men. Habitual
exercise has similar effects on large elastic artery
stiffness with aging in women, but may not be effective for enhancing vascular
endothelial function in some postmenopausal women. The mechanisms by which habitual aerobic
exercise acts to preserve arterial function with aging are incompletely
understood, but reduced oxidative stress appears to be an important
mechanism. Maintained bioactivity of
tetrahydrobiopterin, a critical co-factor for
synthesis of nitric oxide (NO) by endothelial NO synthase,
contributes to the beneficial effects of regular exercise on vascular
endothelial function in middle-aged and older adults by increasing vascular NO
bioavailability. Recent evidence
suggests that regular aerobic exercise also may preserve vascular endothelial
function with aging by protecting arteries against the adverse effects of risk
factors such as circulating LDL-cholesterol. In summary, habitual aerobic exercise
favorably modulates clinically important expressions of arterial aging, thus
preserving vascular function and possibly reducing the risk of age-associated
CVD.
Key words: endothelial function; large artery stiffness