Obesity and Its Effects on the Lungs
While, by any measure, obesity is an epidemic and a medical emergency in the United States and in many places around the world, many still do not understand full breadth of conditions that obesity can cause. Here, we look to describe the effects of obesity on lung function and consequent respiratory dysfunction. It is worth noting that obesity affects the lungs in two ways – both mechanical – in that excess fat pushes on the chest, but also in an inflammatory manner – the hormones produced by adipose tissue or fat cells can affect the lungs as well.
To jump directly into the effects of obesity on the lungs, there is evidence to suggest that obesity is at least partially related to some cases of:
- Asthma (including more severe disease due to weight)
- Sleep apnea
- Obesity hypoventilation syndrome
- And pulmonary hypertension, amongst others
However, not only does obesity cause disease but it can also change the outcomes of treatment in other diseases including acute respiratory distress syndrome and chronic obstructive pulmonary disease. Further obesity can cause in greater susceptibility to infection, especially those that are related to the lungs. This has been shown during the COVID epidemic where those with obesity and its related illnesses showed far poorer outcomes than those who maintained a normal weight.
Obesity and excess fat around the chest wall and abdomen put additional pressure on the lungs. This can change the way we breathe since the movement of the chest and the diaphragm can be restricted due to this excess fat. As a result, the residual and total capacity and of the lungs is reduced significantly and can cause wheezing and shallow breathing. Not only do we know this to be the case, but the lowered capacity of the lungs is proportionally (some studies show exponentially) related to the amount of excess weight a person is carrying. Other lung related issues include:
- Increased lung diffusion
- Respiratory failure
- Airway resistance
- Lowered lung compliance
- And lowered respiratory muscle strength
Importantly, lung function was improved by excess weight loss and consequent reduction in BMI. Even relatively moderate excess weight loss, when compared to the results of bariatric surgery, has positive effects.
- ¹Mafort, T.T., Rufino, R., Costa, C.H. et al. Obesity: systemic and pulmonary complications, biochemical abnormalities, and impairment of lung function. Multidiscip Respir Med 11, 28 (2016). https://doi.org/10.1186/s40248-016-0066-z