Air Pollution, Physical Activity, and Cardiovascular Function of Patients With Implanted Cardioverter Defibrillators: A Randomized Controlled Trial of Indoor Versus Outdoor Activity
- DOI
- Language of the publication
- English
- Date
- 2020-04-02
- Type
- Article
- Author(s)
- Liu, Ling
- Urch, Bruce
- Nanthakumar, Kumaraswamy
- Chen, Li
- Smith-Doiron, Marc
- Brook, Jeffrey R.
- Speck, Mary
- Silverman, Frances
- Stieb, David M.
- Publisher
- Lippincott, Williams & Wilkins
Abstract
Objective: To investigate whether implanted cardioverter defibrillator (ICD) patients exercising indoors on higher air pollution (AP) days had reduced adverse cardiovascular effects compared with those exercising outdoors. Methods: Eighteen participants were randomly divided into control or intervention groups. Blood pressure (BP), pulse rate (PR), and oxygen saturation (O2SAT) were measured daily before and after participants walked outdoors for 30 minutes. On days with higher forecast AP the intervention group exercised indoors. Results: AP was significantly associated with increased BP and PR, and reduced O2SAT. After adjustment for exercise levels, AP was associated with increased diastolic BP and PR in controls only. Significant improvements in cardiovascular measures over time were observed in both groups. Conclusion: In ICD patients, reducing AP exposure may reduce adverse cardiovascular effects, while daily mild exercise may benefit cardiovascular function.
Plain language summary
The Air Quality Health Index (AQHI) is a risk communication tool intended to provide information to the public on current and forecast air quality conditions. It was developed by the Canadian government to help the public make decisions to limit short-term exposure to air pollution and adjust their activity when air pollution levels are high, particularly for people who have heart and lung conditions. Little research has been done to characterize the benefits of following AQHI advice. This study investigated whether patients with an implanted cardioverter defibrillator (ICD) who followed advice to exercise indoors on high AQHI days had reduced adverse impacts on cardiovascular measures compared with those who exercised outdoors on those days. Participants were randomly divided into the control and intervention groups. Both groups walked for 30 minutes outdoors every day for maximum 70 days, and their blood pressure, pulse rate and blood oxygen saturation pre- and post-exercise were measured. Hourly ambient concentrations of PM2.5, O3, NO2, sulphur dioxide and carbon monoxide were collected, and AQHI calculated. On days forecast with AQHI ≥5, the intervention group was advised to exercise indoors. The results show that increased levels of air pollutants were significantly associated with adverse cardiovascular measures in the patients. Air pollutants were significantly associated with changes between post- and pre-exercise in diastolic blood pressure and pulse rate in the control group, but not in the intervention group. During the exercise period, a significant improvement in all cardiovascular measures was observed in the participants. The results suggest that air pollution was associated with adverse changes in cardiovascular measures in ICD patients. Advice to reduce exposure to air pollution based on AQHI levels may help reduce adverse impact on cardiovascular measures. Daily mild exercise may benefit cardiovascular function in this cohort of ICD patients.
Subject
- Health,
- Health and safety