Arterial stiffness is higher in older adults with increased perceived fatigue and fatigability during walking

We investigated whether central and/or peripheral arterial stiffness contributes to increased perceived fatigue during walking in mobility-intact older adults. Arterial stiffness of the common carotid artery and superficial femoral artery (SFA) was measured using Doppler-ultrasound in 45 community-dwelling women and men (60-78yrs). The change in perceived fatigue was measured after a fast-pace 400meter walk test. Adults that rated feeling more tired after walking (n=10) had higher SFA stiffness (p<0.01), but not carotid artery stiffness, than adults that reported feeling more energetic after walking (n=22). The change in perceived fatigue rating was normalized to energy expenditure during walking to determine perceived fatigability. Adults were divided into lower and higher perceived fatigability groups (n=22 per group). Carotid artery stiffness was not different between perceived fatigability groups after adjusting for age, sex, body fat, systolic blood pressure, fasting blood glucose, daily physical activity levels, and resting diameter. However, SFA stiffness was significantly elevated in the higher as compared to lower perceived fatigability group (β-index: 20.7±1.3 vs. 15.3±1.4U; p=0.02) after adjusting for the abovementioned variables. Moreover, stepwise regression identified SFA β-index to be an independent predictor of perceived fatigability (r²=0.38, p<0.01). These results suggest that peripheral arterial stiffness is independently associated with perceived fatigue and fatigability in older adults.