Achieving Canadian physical activity guidelines is associated with better vascular function independent of aerobic fitness and sedentary time in older adults

Canadian physical activity guidelines recommend older adults accumulate 150 min of weekly moderate to vigorous physical activity (MVPA). Older adults who are insufficiently active may have reduced blood vessel health and an increased risk of cardiovascular disease. We tested this hypothesis in 11 older adults who did (7 female; age, 65 +/- 5 years; MVPA, = 239 +/- 81 min/week) and 10 older adults who did not (7 female; age, 68 +/- 9 years; MVPA, 95 +/- 33 min/week) meet MVPA guidelines. Flow-mediated dilation (FMD) in the brachial (BA) and popliteal (POP) arteries, as well as nitroglycerin-mediated dilation (NMD; endothelial-independent dilation) in the POP were assessed via ultrasonography. Aerobic fitness (peak oxygen uptake) was determined using a graded, maximal cycle ergometry test via indirect calorimetry. MVPA and sedentary time were assessed over 5 days using the PiezoRx and activPAL, respectively. There were no differences in peak oxygen uptake (26 +/- 10 vs. 22 +/- 10 mL O-2/(kg.min); p = 0.26) or sedentary time (512 +/- 64 vs. 517 +/- 76 min/day; p = 0.87) between groups; however, those who achieved the MVPA guidelines had a higher BA-FMD (5.1% +/- 1.3% vs. 3.6% +/- 1.7%; p = 0.03), POP-FMD (2.6% +/- 1.1% vs. 1.3% +/- 0.8%; p = 0.006), and POP-NMD (5.1% +/- 1.7% vs. 3.3% +/- 2.1%; p = 0.04). In the pooled sample, MVPA was moderately correlated to both BA-FMD (r = 0.53; p = 0.01) and POP-NMD (r = 0.59; p = 0.005), and strongly correlated to POP-FMD (r = 0.85; p < 0.001). Collectively, our results provide supporting evidence that meeting MVPA guidelines is associated with better vascular function and may reduce the risk of developing cardiovascular disease in older adults. Furthermore, these data suggest that weekly MVPA time may have a greater impact on blood vessel function than aerobic fitness and weekly sedentary time.