TABLE 4.
Measurements of cerebrovascular response to exercise and components of cerebrovascular kinetics at baseline and 12 wk in the intervention and control arms
| Intervention, mean ± SD (n = 19) | Control, mean ± SD (n = 7) | ||||||
|---|---|---|---|---|---|---|---|
| Variable | Baseline | 12 wk | Change | Baseline | 12 wk | Change | P |
| Resting MCAV, cm/s | 60.7 ± 12.4 | 58.8 ± 10.7 | −1.8 ± 8.8 | 55.6 ± 16.1 | 51.9 ± 13.3 | −3.7 ± 12.1 | 0.42 |
| Resting HR, bpm | 79 ± 11 | 77 ± 11 | −1.9 ± 8.2 | 73 ± 11 | 73 ± 11 | −0.92 ± 4.7 | 0.95 |
| Resting MAP, mm Hg | 101.0 ± 24.8 | 103.0 ± 21.3 | 1.4 ± 18.6 | 87.8 ± 13.7 | 89.9 ± 20.7 | 2.1 ± 19.9 | 0.51 |
| Resting PETCO2, mm Hg | 32.4 ± 3.10 | 33.1 ± 3.5 | 0.75 ± 4.7 | 33.7 ± 3.29 | 32.4 ± 3.3 | −1.4 ± 3.1 | 0.53 |
| CVR, cm/s | 9.0 ± 4.3 | 9.0 ± 4.7 | −0.4 ± 4.8 | 12.4 ± 5.9 | 10.9 ± 2.3 | −1.5 ± 4.9 | 0.71 |
| Time delay, s | 32.3 ± 31.5 | 19.3 ± 47.9 | −13.0 ± 50.6 | 44.4 ± 43.5 | 49.0 ± 32.5 | 4.6 ± 56.9 | 0.17 |
| Amplitude, cm/s | 9.3 ± 3.2 | 9.6 ± 4.3 | 0.3 ± 5.5 | 12.6 ± 5.6 | 10.6 ± 3.0 | −2.0 ± 6.1 | 0.62 |
| Time constant, τ, s | 36.3 ± 17.4 | 47.6 ± 47.5 | 11.3 ± 42.8 | 38.8 ± 26.5 | 47.2 ± 58.1 | 8.4 ± 61.7 | 0.93 |
| Steady-state HR, bpm | 118 ± 18 | 112 ± 22 | 1.3 ± 21.3 | 105 ± 19 | 102 ± 20 | −0.8 ± 18.2 | 0.46 |
| Steady-state MAP, mm Hg | 124 ± 26 | 125 ± 26 | 1.3 ± 20.2 | 110 ± 15 | 110 ± 28 | −0.7 ± 18.2 | 0.59 |
| Steady-state PETCO2, mm Hg | 34.8 ± 4.3 | 35.8 ± 3.45 | 0.9 ± 4.88 | 38.8 ± 4.5 | 37.8 ± 3.9 | −1.0 ± 2.7 | 0.71 |
| Work rate, watts | 83.1 ± 16.5 | 83.1 ± 16.8 | 0.9 ± 15.1 | 90.0 ± 20.6 | 88.9 ± 23.3 | −1.1 ± 10.5 | 0.93 |
The P values were calculated using ANCOVA.
CVR, cerebrovascular response; HR, heart rate; MAP, mean arterial pressure; MCAV, middle cerebral artery velocity; PETCO2, end-tidal carbon dioxide.