Obesity has long been recognized as a significant risk factor for asthma. Nearly 60 percent of patients with severe asthma are obese, presenting a host of treatment challenges. In general, obese patients do not respond as well to conventional asthma therapies as lean patients. This leaves health care providers on the hunt for new options.

Anne Dixon

Successfully treating patients with obesity and asthma requires an understanding of the factors associated with obesity and the state of metabolic dysregulation, as well as the inflammatory phenotype of the airway disease for appropriate medical management, according to Anne E. Dixon, MD, ATSF, a professor at the University of Vermont in Burlington.

“Obesity and associated factors (high fat, low fiber diet, and metabolic syndrome) profoundly alter adaptive and innate immune function, increase susceptibility to respiratory infection, and alter prototypical pathways that cause asthma,” said Dr. Dixon. “These changes alter response to standard treatments, and often lead to severe, difficult-to-control disease.”

Adult asthma affects the peripheral airway, a zone of the lung not easily measured by conventional lung function testing. It has a unique physiological signature compared with asthma in lean patients, according to Dr. Dixon. 

Dr. Dixon will co-chair a panel of physicians and scientists during today’s session to examine the pathophysiology of the different phenotypes of obese asthma, and how this affects treatment responses. The panelists will discuss the role of medications, lifestyle interventions, and co-morbidities, including a sharp focus on depression and obstructive sleep apnea. The speakers will preview future therapies in development for this challenging new patient population, as well.

In developing a treatment approach, speakers will explore several options, including treatments that address the phenotype of asthma—specifically whether there is evidence of a corticosteroid-sensitive pathway. Additional treatment discussions will take shape over long-term systemic corticosteroids, which Dr. Dixon said actually worsen the disease, and the importance of a proper diet, exercise, and weight loss. In fact, studies suggest that weight loss of between 5 and 10 percent may produce significant improvement in asthma control.

Diet isn’t the only thing that contributes to obesity. Tobacco smoke and air pollution lead to obesity and further obstruct airway health, Dr. Dixon said.

“Discuss lifestyle changes with your patients and consider a referral to a weight loss program,” Dr. Dixon said. “Evaluate [patients] for co-morbidities that may be contributing to asthma severity. It’s important to understand that obesity profoundly alters asthma, and conventional treatments for asthma may have limitations, particularly in patients with little in the way of type 2 inflammation.”