The Effect of Obesity on Asthma

Obesity has long been recognized as a predisposing factor for several chronic diseases like heart disease, diabetes, and has globally affected people in many parts of the world. However, there is increasing evidence that obesity is also closely related to asthma. It has been observed that obesity is associated with a higher risk of asthma and is also responsible for more severe asthma symptoms. Whether obesity causes asthma or asthma predisposes a person towards obesity is a question that does not have an obvious answer. It has been observed that obesity-related asthma responds differently to medications. However, one thing clearly shows that reduction in weight produces an immediate decrease in the severity of asthma symptoms.

The Role of Obesity

Several reasons have been put forward for the close link between obesity and asthma. There is no doubt that obesity, in general, leads to more discomfort in breathing even though there may not be an underlying respiratory disease. On the other hand, it is a well-known fact that people with asthma tend to be less physically active, which tends to make them obese. 

  • Asthma is characterized by inflammation, tightening of muscles around the airway, and hypersensitivity. This leads to difficulty in breathing. Obesity in itself causes problems in breathing as the lungs have less capacity.
  • In addition to this, more effort is required by the obese to lift the chest wall as it has too much adipose or fat tissue.
  • Obesity in the upper body or around the abdomen imposes higher respiratory load as diaphragm dysfunction is caused by deposits of adipose tissue around the belly. 
  • Obesity is also associated with chronic inflammation, a factor that it has common with asthma. However, the underlying mechanisms are not clearly understood.
  • Several hormones like leptin released from adipose tissue lead to a tendency towards inflammation. Though no direct relationship has been observed between leptin and asthma, children who are obese and asthmatic tend to have higher levels of leptin.
  • Another possible reason is that obesity often leads to GERD, which in turn worsens asthma symptoms. 
  • Besides this, obstructive sleep apnea is closely related to obesity and worsens night time symptoms for people with asthma.
  • One of the reasons the obese face more severe symptoms is that their reaction to bronchoconstriction is much more intense, leading to more severe asthma symptoms.
  • Peripheral airways of the obese are less in diameter, thereby leading to an aggravated response to constriction.

The implication for Management of Asthma

All the factors that influence the relation between obesity and asthma may not be clear, but compelling evidence does provide another strong reason to cut down on those extra kilos. Weight loss reduces the severity of asthma symptoms and improves one’s response to medications, thereby leading to a better quality of life for asthmatics. Thus, instead of merely increasing medication for asthma management, a concerted effort should also be devoted to weight management through lifestyle changes as part of treatment for asthma.