(RxWiki News) If you're obese, your body may be under stress. Carrying all that extra weight can increase your risk of many health problems, including asthma. If you already have asthma, obesity can make it worse.
Overweight and obese people who lost weight significantly reduced their asthma symptoms and improved their asthma control, according to a recent study.
"Lose weight to help control your asthma."
"Obesity is a major health problem, and is associated with a high incidence of asthma and poor asthma control," wrote Charlotte Ulrik, associate professor at the University of Copenhagen, and colleagues.
"More recently, obesity has also been recognized as a potential risk factor for more severe asthma," they continued.
So, the researchers set out to see if weight loss could improve asthma.
"In general, all studies published so far show that weight loss in obese asthmatics improves asthma control," the authors said.
People who lost weight through surgery had especially significant improvements in their asthma. Weight loss surgery reduced asthma symptoms and use of asthma medications.
In one study, 48 percent of patients had complete asthma remission (no symptoms and no medication use) after weight loss surgery. In total, 90 percent of patients had improved asthma symptoms after surgery.
Another study found that the use of inhaled steroids decreased from 50 percent to 30 percent after weight loss surgery, suggesting that weight loss surgery lowers the drug requirements for controlling asthma symptoms.
A Swedish study showed a 49 percent decrease in respiratory drug prescription fills.
Other methods of weight loss also proved beneficial for asthma patients.
A study looking at the effects of an 8-week weight loss program showed that people who lost weight had improved forced vital capacity (total amount of air that can be expelled from lungs), reduced shortness of breath, reduced use of medication, and fewer exacerbations or fits.
"Studies have also shown that weight loss in obese asthmatics is associated with improvements in level of lung function and airway responsiveness to inhaled methacholine, whereas no significant improvements have been observed in exhaled nitric oxide or other markers of eosinophilic airway inflammation," the authors write.
In other words, these findings show that weight loss does not improve asthma-causing inflammation as much as it improves symptoms and lung function.
"It is therefore probable that weight loss-induced improvements in asthma control - defined as symptoms, level of lung function, and use of medication - occur due to a reduction in mass loading on the respiratory symptoms rather than improvements in asthma per se," they write.
More simply, losing weight takes stress off the lungs and airways.
The authors concluded that overweight and obese people with asthma experience a large reduction in symptoms and improvement in asthma control after weight loss. However, the findings show that the benefits of weight loss do not improve inflammation.
"Very interestingly, all papers identified for this study reported some positive effect of weight loss on asthma control," they wrote.
This systematic review of past studies was published June 7 in the Journal of Asthma and Allergy.