Adult asthmatics at higher risk of developing obesity, reveals study

Canada: In a new study published in the BMJ journal Thorax it was shown that adult asthmatics are more likely to acquire obesity than non-asthmatics, especially those who are non-atopic, have a longer illness duration, or are taking oral corticosteroids.

Obesity is well-known to be a risk factor for asthma. Although there is evidence that asthma causes obesity in children, the relationship between asthma and obesity in adults has not been studied. As a result, Subhabrata Moitra and colleagues undertook this study to investigate the impact of atopy and asthma treatment on the development of obesity.

The researchers analyzed data from the European Community Respiratory Health Survey (ECRHS), a cohort study conducted in 11 European nations and Australia across three waves between 1990 and 2014, at around ten-year intervals. There were two study eras considered: ECRHS I (t) to ECRHS II (t+1), and ECRHS II (t) to ECRHS III (t+1). At visit t, they removed those who were obese (body mass index 30 kg/m2). The multivariable modified Poisson regression (lag) with repeated measurements was used to evaluate the relative risk (RR) of obesity at t+1 related to asthma.

The key findings of this study were as follows:

1. This study comprised 7576 individuals from ECRHS I-II (51.5% female, 34 (7) year mean (SD) age) and 4976 from ECRHS II-III (51.3% female, 42 (8) year mean (SD) age).

2. In ECRHS I-II, 9% of individuals were fat, whereas 15% became obese in ECRHS II—III.

3. The risk of developing obesity was higher in asthmatics than in non-asthmatics (RR 1.22), and especially higher in non-atopics than atopics (1.47; 1.17 to 1.86 vs 1.04; 0.86 to 1.27), those with longer disease duration (1.32; 1.10 to 1.59 in >20 years vs 1.12; 0.87 to 1.43 in 20 years), and those on oral corticosteroids (1.99; 1.26 to 3.15 vs 1.15; 1.03 to 1.28). 

4. Physical activity wasn't really shown to be a moderator of this connection.

In conclusion, Oral corticosteroid usage and asthma duration may be confounders, indicating that asthma severity is the major factor related to obesity incidence. The research, on the other hand, emphasizes the need of using oral corticosteroids with caution in asthmatics, since they may be the only controllable component leading to obesity.

Reference:

Moitra, S., Carsin, A.-E., Abramson, M. J., Accordini, S., Amaral, A. F. S., Anto, J., Bono, R., Casas Ruiz, L., Cerveri, I., Chatzi, L., Demoly, P., Dorado-Arenas, S., Forsberg, B., (2022). Long-term effect of asthma on the development of obesity among adults: an international cohort study, ECRHS. In Thorax. BMJ. https://doi.org/10.1136/thoraxjnl-2021-217867