According to a new study, having adult asthma significantly increases the likelihood of becoming obese later in life.
Results from an extensive investigation that included over 8,700 participants from Australia, Belgium, Estonia, France, Germany, Iceland, Italy, Norway, Spain, Sweden, Switzerland, and the UK revealed that adults with asthma are at an elevated risk of obesity, signifying unprecedented associations between the conditions.
The study, led by the Barcelona Institute of Global Health (ISGlobal), found that the risk between adult asthma and obesity was highest for those with non-allergic asthma, those who have had the condition for an extended period, or people who use corticosteroids.
The study results are published in Thorax.
Subhabrata Moitra, who conducted the study at ISGlobal and is a researcher at the University of Alberta, commented: “Several studies have shown that asthma and obesity share some common socioeconomic, behavioural and environmental risk factors that can lead to the development of both diseases. Some previous research focused on the mechanisms by which obesity could lead to asthma, but the inverse relationship had not received much attention until recently.”
Long-term effects of adult asthma
To analyse the potential long-term impacts of adult asthma, the researchers utilised data from the European Community Respiratory Health Survey (ECRHS), which was obtained in three waves between 1990 and 2014, with follow-up intervals of ten years. The project collected data in questionnaires, lung function tests, and measures that calculated participants’ body mass index (BMI) and asthma status.
Between the first two follow-ups, 14.6% of the participants without asthma developed obesity, whereas 16.9% of those with adult asthma became obese. However, the variation between the two groups became more significant when the team translated it into a relative risk that considered factors such as smoking. When taking this into account, people with adult asthma had a 21% increased risk of the disease compared to non-asthmatic participants.
The researchers identified that people who had adult asthma for a prolonged duration had a 32% increased risk of obesity than those who had it for a shorter period. Moreover, those with non-allergic asthma had a 47% increased risk than people with allergic asthma. Individuals who were treating the disease with corticosteroids – anti-inflammatory medications – had a 99% higher risk of obesity than those not using the treatments. Previous research has identified an association between corticosteroids and abnormal weight gain.
Judith Garcia-Aymerich, Head of the Non-Communicable Diseases and Environment Programme at ISGlobal and senior author of the study, said: “A potential explanation for the weight gain associated with asthma could be the reduction of physical activity in asthmatic patients. However, our results do not support this hypothesis since the levels of physical activity in our study did not affect the observed association. Regardless of the mechanisms, still unknown, our results have implications for the clinical care of adults with asthma.”
Although prior research discovered a link between asthma and weight gain in women exclusively, this study found no sex differences. Furthermore, an earlier study had identified an association between childhood asthma and obesity after ten years of follow-up; however, this is the first study to demonstrate a similar association between adult asthma and obesity regardless of gender.