Cerebrovascular function in patients with chronic obstructive pulmonary disease: the impact of exercise training

Abstract

This study examined cerebral blood flow (CBF) and its regulation before and after a short-term periodized aerobic exercise training intervention in patients with chronic obstructive pulmonary disease (COPD). Twenty-eight patients with COPD (forced expiratory volume in 1 s/forced vital capacity < 0.7 and <lower limit of normal) and 24 healthy control subjects participated in the study. Extracranial CBF (duplex ultrasound), middle cerebral artery velocity (MCAv; transcranial Doppler), cerebrovascular reactivity to hypocapnia and hypercapnia, and dynamic cerebral autoregulation (transfer function analysis) were quantified. These tests were repeated in both patients with COPD ( n = 23) and control subjects ( n = 20) after 8 wk of periodized upper and lower body aerobic exercise training (3 sessions/wk). At baseline, global extracranial CBF was comparable between the COPD and control groups (791 ± 290 vs. 658 ± 143 ml/min, P = 0.25); however, MCAv was lower in patients with COPD compared with control subjects (46 ± 9 vs. 53 ± 10 cm/s, P = 0.05). Although there were no group differences in dynamic cerebral autoregulation or the MCAv response to hypercapnia, patients with COPD had a lower MCAv response to hypocapnia compared with control subjects (−1.1 ± 1.5 vs. −1.6 ± 1.3 cm·s−1·mmHg−1, P = 0.02). After aerobic training, absolute peak O2 consumption increased in both groups, with a greater improvement in control subjects (1.7 ± 0.4 vs. 4.1 ± 0.2 ml·kg−1·min−1, respectively, P = 0.001). Despite these improvements in peak O2 consumption, there were no significant alterations in CBF or any measures of cerebrovascular function after exercise training in either group. In conclusion, patients with COPD have a blunted cerebrovascular response to hypocapnia, and 8 wk of aerobic exercise training did not alter cerebrovascular function despite significant improvements in cardiorespiratory fitness. NEW & NOTEWORTHY No study to date has investigated whether exercise training can alter resting cerebral blood flow (CBF) regulation in patients with chronic obstructive pulmonary disease (COPD). This study is the first to assess CBF regulation at rest, before, and after aerobic exercise training in patients with COPD and healthy control subjects. This study demonstrated that while exercise training improved aerobic fitness, it had little effect on CBF regulation in patients with COPD or control subjects.

Dynamic cerebral autoregulation of endurance-trained men following 6 weeks of high-intensity interval training to exhaustion

“…One possible explanation might be that despite an ~18% increase in CRF, the sedentary older participants (>64 years) studied by Lewis et al (2019) had significantly lower CRF levels at baseline than our young endurance-trained men (26 to 28 years). These results support that elevated CRF is associated with diminished dCA, whereas dCA is maintained in individuals with lower CRF (20). Further research is required to elucidate whether a threshold exists above which CRF will be associated with an attenuated dCA.…”

“…In that report, we showed that elevated CRF was associated with increased TFA gain during 0. To our knowledge, only one other longitudinal study assessed dCA following aerobic exercise training of varied nature and intensity (20). These authors reported no training effect on dCA in healthy older sedentary participants.…”

“…Longitudinally, short-term aerobic exercise of varied nature (continuous or interval training), intensity and duration [12 weeks (6,26) and 8 weeks (20)] has been associated with improved CRF in healthy individuals. In association with this training-induced CRF improvement, some investigators reported a small but significant increase in MCAvmean following a 12-week program (26), whereas others did not observe any change in MCAvmean (20) or whole-brain CBF (6) after respectively 8 and 12 weeks of training.…”

“…Indeed, while some investigators reported no noticeable differences in dCA between endurance-trained individuals (13) or Masters athletes (2) with untrained individuals, our research group (17) and others (22) observed diminished dCA with elevated CRF. Nonetheless, traininginduced effects on dCA in cardiorespiratory fit individuals remain unexplored while dCA seems not to be influenced by aerobic exercise training in older healthy sedentary participants and chronic obstructive pulmonary disease patients (20).…”

Does depth of squat‐stand maneuver affect estimates of dynamic cerebral autoregulation?

“…In order to improve the coherence values, the SNR must be increased by inducing larger BP oscillations (Van Beek et al, 2008). Squat-stand maneuvers (SSM) provide an effective, reproducible, and tolerable way of manipulating BP for the assessment of CA that can be used in healthy adult populations (Barnes, Ball, Haunton, Robinson, & Panerai, 2017Labrecque et al, 2017;Lewis et al, 2019;Smirl et al, 2014;Smirl, Hoffman, Tzeng, Hansen, & Ainslie, 2015;Zhang et al, 2009). The main drawback of SSM is the difficulty of their use in incapacitated subjects, people with mobility issues or those with cognitive impairment (Van Beek et al, 2008;Smirl et al, 2015).…”