Impaired cerebrovascular reactivity in chronic obstructive pulmonary disease

Impaired cerebrovascular reactivity (CVR) is associated with stroke. Cerebrovascular diseases are common comorbidity in chronic obstructive pulmonary disease (COPD) patients. The aim of our study was to quantify CVR in the anterior and posterior cerebral circulation during voluntary breath-holding in COPD patients according to airflow limitation severity. In this cross-sectional study, we compared 90 COPD patients without previous cerebrovascular disease and 30 age- and sex-matched healthy volunteers (mean age 67 +/- 7.9, 87 males). Using transcranial Doppler ultrasound and breath-holding index (BHI), we analysed baseline mean flow velocities (MFV) and CVR of middle cerebral artery (MCA) and basilar artery (BA). Our results demonstrated that COPD patients had lower baseline MFV of both MCA and BA than controls. COPD patients had significantly lower BHI(m)MCA and BHI(m)BA than controls (0.8 and 0.7 versus 1.24 and 1.07, respectively; p<0.001). With the severity of airflow obstruction, there were significant declines of BHI(m)MCA and BHI(m)BA in mild (0.94 and 0.83), moderate (0.8 and 0.7) and severe to very severe COPD (0.7 and 0.6), respectively (p<0.001). For all participants, we found a significant and positive correlation between forced expiratory volume in one second (FEV1) and BHI(m)MCA (Rho=0.761, p<0.001) and between FEV1 and BHI(m)BA (Rho=0.409, p<0.001). COPD patients have impaired CVR in anterior and posterior cerebral circulation. Impairment of CVR increase with the airflow limitation severity. CVR is an appropriate marker to identify vulnerable COPD subjects at high risk to develop cerebrovascular disease. Prospective studies are needed for further evaluation.