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

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 316; no. 2; pp. H380 - H391
• Main Authors: Lewis, Nia, Gelinas, Jinelle C. M., Ainslie, Philip N., Smirl, Jonathan D., Agar, Gloria, Melzer, Bernie, Rolf, J. Douglass, Eves, Neil D.
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.02.2019
• Subjects: Aerobics; Aged; Aged, 80 and over; Blood flow; Brain - blood supply; Brain - diagnostic imaging; Carbon dioxide; Cardiorespiratory fitness; Cerebral blood flow; Cerebrovascular Circulation; Cerebrovascular system; Chronic obstructive pulmonary disease; Exercise; Exercise Therapy - methods; Female; Fitness training programs; Function analysis; Humans; Hypercapnia; Hypocapnia; Lung diseases; Male; Middle Aged; Obstructive lung disease; Patients; Physical fitness; Pulmonary Disease, Chronic Obstructive - diagnostic imaging; Pulmonary Disease, Chronic Obstructive - physiopathology; Pulmonary Disease, Chronic Obstructive - therapy; Training; Transfer functions; Ultrasound; cerebral blood flow; exercise; chronic obstructive lung disease
• ISSN: 0363-6135; 1522-1539; 1522-1539
• DOI: 10.1152/ajpheart.00348.2018

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 O 2 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 O 2 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.