People with asthma face much greater risks of suffering from additional diseases than those without it, a problem that has long been overlooked by the medical community, according to a new study by Canadian researchers.
Asthmatics will often see their physicians or visit hospitals more often than the general population for treatment of their lung ailment.
But the study found that people with asthma are also more likely to see their doctors, go to the emergency room or end up in hospital for health problems unrelated to asthma.
"I think it tells us asthma is not only a disease of the lungs, it affects the rest of the body," said Andrea Gershon, a scientist at the Institute for Clinical Evaluative Sciences in Toronto and lead author of the study published in the medial journal Thorax on Tuesday.
"I think we need to start thinking bigger when we think about asthma."
Asthmatics see their doctors for other health problems 72 per cent more often than those without asthma, the study found. They are most likely to suffer respiratory diseases, psychiatric problems and musculoskeletal diseases, it said.
It also found that asthmatics go to the emergency department for other diseases more than twice as often as non-asthmatics and require hospitalization 66 per cent more often for reasons unrelated to asthma.
The study was conducted using health databases of Ontario residents in 2005.
The researchers found that asthma and its co-morbidities - conditions that coexist with the primary disease - were responsible for 6 per cent of the 2.2 million hospitalizations in Ontario in 2005, 9 per cent of the nearly five million emergency room visits, and 6 per cent of the more than 130 million outpatient visits that year.
There is no evidence that asthma causes these additional health problems, Dr. Gershon said.
It's possible that physical activity limitations caused by asthma may lead to other health problems such as depression, osteoporosis or obesity, the study said. But side effects from asthma medications could also lead to the development of other health problems.
Some people with asthma may be subject to genetic or environmental factors that make them susceptible to certain additional diseases, the study said.
"It's still early days in this type of research, and we have a lot to figure out," said Dr. Gershon, who is also a respirologist and scientist at Sunnybrook Health Sciences Centre in Toronto.
There hasn't been a significant amount of research dedicated to examining asthma and its co-morbidities, even though these can have a significant impact on an individual's life.
Chronic Diseases in Canada, a quarterly scientific journal published by the Public Health Agency of Canada, published research from the University of British Columbia in March showing that adults with asthma in that province are much more likely to suffer from an additional disease.
Dr. Gershon said more research should be done to understand the link between asthma and co-morbidities to help prevent them and treat patients who are experiencing them. Doctors should also be on the lookout for these co-morbidities, Dr. Gershon said.