| Hazy Day Workout Could Exacerbate Heart Problem |
| 来源:Suzanne Rostler;添加日期:2002-8-3;编辑:artemis |
NEW YORK (Reuters Health) - Jogging through the streets of Manhattan or in the hills around Los Angeles may seem like the best way for a city dweller to combine urban living and healthy exercise. But, according to researchers, it can put heart disease patients at risk.
Their study in Helsinki, Finland found that individuals with a history of heart disease were about three times more likely to suffer myocardial ischemia--decreased oxygen supply to the heart--when they exercised 2 days after levels of a certain type of air pollution were elevated. Consequently, patients may be at risk of heart attack or chest pain while exercising.
In an interview with Reuters Health, Dr. Murray A. Mittleman from Harvard Medical School ( news - web sites) in Boston, Massachusetts recommended that heart disease patients avoid outdoor activity on hot and hazy days. However, Mittleman stressed that the findings apply only to people with heart disease, not to healthy individuals.
If your baseline risk of heart attack is low on any given day, even if there is an increased risk from air pollution, the absolute risk is still tiny, he said.
Nonetheless, clean air standards are bound to have a positive public health impact since air pollution has also been linked with respiratory problems and cancer, Mittleman and colleagues write in an editorial accompanying the study.
The problem of particulate air pollution is pervasive and growing. An even greater concomitant impact on public health from this insidious contributor to cardiac disease can be anticipated, the editorialists write in the July 29th rapid access issue of Circulation: Journal of the American Heart Association ( news - web sites).
The study included data from 342 exercise tests from 45 patients with coronary artery disease. Patients were monitored with an ECG while exercising on a bicycle twice a week over 6 months.
The researchers, led by Dr. Juha Pekkanen from the National Public Health Institute in Kuopio, Finland, tracked air levels of fine particles (the type of pollution associated with emissions from factory smokestacks) and ultra-fine particles (those that come from diesel exhaust pipes).
Twenty-three patients experienced exercise-induced ischemia when exercising 2 days after air pollution levels were high. All other patients had episodes of ischemia regardless of air quality or did not experience ischemia at all, according to the study results.
SOURCE: Circulation 2002;10.1161/01.CIR.0000027561.41736.3C. |
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