Air Pollution, Physical Activity and Cardiovascular Function of Patients With Implanted Cardioverter Defibrillators: A Randomized Controlled Trial of Indoor Versus Outdoor Activity
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 18
- 主要终点
- blood pressure
研究概览
简要总结
This study investigated whether patients with an implanted cardioverter defibrillator (ICD) who followed advice to exercise indoors on high air pollution 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 air pollutants were collected. On days forecast with Air Quality Health Index was equal to or higher than 5, the intervention group was advised to exercise indoors.
详细描述
Background: 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 are sensitive to air pollution. Little research has been done to characterize the benefits of following AQHI advice. The AQHI is based on a weighted sum of concentrations of nitrogen dioxide (NO2), ozone (O3), and particulate matter of median aerodynamic diameter ≤ 2.5 µm (PM2.5) to provide information to the public on current and forecasted air quality conditions.
Objective
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.
Methods: Participants with ICD were randomly divided into the control and intervention group. Both groups did daily 30-minute walked outdoors for maximum 70 days, and their data on blood pressure, pulse rate and blood oxygen saturation pre- and post-exercise were collected. Hourly ambient concentrations of PM2.5, O3, NO2, sulphur dioxide (SO2) and carbon monoxide (CO) were collected, and AQHI calculated. On days forecast with AQHI ≥5, the intervention group was advised to exercise indoors. Mixed-effects models were applied to analyze the associations between air pollution and cardiovascular measures.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Patients with structural heart disease with an implanted cardioverter difribrillator (ICD) in situ
- •18 years of age and older
- •living and working in Toronto (Canada) and surrounding area
- •The participants are healthy enough for mild outdoor activity (a 30-minute walk).
排除标准
- •Decompensated heart failure (CHF) patients defined as a hospital admission for CHF or intravenous ionotropic administration within the preceding 6 months
- •patients on class 1 and 11 antiarrhythmics and congenital heart disease patients
- •patients who have experienced frequent or recent shocks (within the last 3 months of the experiment)
- •patients who have underlying conditions that would interfere with mild daily exercise.
研究组 & 干预措施
Control group
The control group did daily mild exercise (walking) outdoors for 30 minutes, for maximum 70 days.
Intervention group
When Air Quality Health Index is below level 5, the intervention group did daily mild exercise (walking) outdoors for 30 minutes. When Air Quality Health Index is equal to or above level 5, the group is advised to do mild exercise indoors for 30 minutes. Total study period lasted for maximum 70 days.
干预措施: Intervention group (Other)
结局指标
主要结局
blood pressure
时间窗: before and after 30-minute exercise
Systolic and diastolic blood pressure is measured in the dominant arm with the subject seated, using an automated sphygmomanometer (BIOS Medical, Newmarket, Ontario, Canada), taking the average of the three readings one minute apart
pulse rate
时间窗: before and after 30-minute exercise
Pulse rate is measured using the pulse oximeter.
blood oxygen saturation
时间窗: before and after 30-minute exercise
Oxygen saturation is measured using a pulse oximeter with a finger sensor (Choice MMed, Beijing Choice Electronic, China). The oximeter is run continuously for 3 minutes to obtain each measurement and the average oxygen saturation during this period is recorded.
次要结局
未报告次要终点
研究者
Ling Liu
Head, Air Health Effects Research Section
Health Canada