Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition where breathing becomes difficult due to a diminished function of the lungs and airways. It occurs in two main forms: emphysema and chronic bronchitis. With emphysema, the elastic tissue that aids exhaling air, as well as the walls between the tiny air sacs in the lungs, become damaged and no longer function properly. With chronic bronchitis, the walls of the bronchial tubes become inflamed and thickened, and produce excess mucus. Most people with COPD have a combination of these two conditions.
Tobacco smoking is the leading risk factor for COPD, and the majority of COPD cases are attributable to cigarette smoking. However, there are other risk factors, including genetics and exposure to pollution, fumes and chemicals, and there are people with COPD who have never smoked. Some research also suggests that excess bodyweight and a lack of physical activity are associated with COPD symptoms.
The research looked at self-reported data taken from more than 113,000 participants in the National Institutes of Health-AARP Diet and Health Study, which began in 1995. While none of the participants reported COPD-like symptoms at the start of the study, 3,648 participants reported having COPD symptoms in the follow-up years between 1996 and 2006. The researchers discovered that obese people—as measured by body-mass index (BMI)—accounted for a greater percentage of those who reported COPD symptoms than did slimmer people.
How could COPD, a disease of the lungs, be associated with being overweight or obese? Carrying excess weight can impact breathing and exacerbate the symptoms of respiratory conditions, including COPD. Obesity can also contribute to inflammation, according to Gundula Behrens, PhD, a researcher in the department of epidemiology and preventive medicine at the University of Regensburg in Germany and co-author of the study. Cells in the immune system secrete proteins called cytokines, and one type of cytokines, known as pro-inflammatory cytokines, cause an inflammatory response in the body.
"The fat tissue that is most active in the production of pro-inflammatory cytokines is visceral fat, which is found in the abdomen," Behrens says. "Those pro-inflammatory cytokines circulate through the body, and increased levels of those cytokines may stimulate COPD-related processes in the lung."
If you have been diagnosed with COPD, there are a number of steps you can take to slow the progression of the disease. At the top of this list is to quit smoking (if you smoke, and you haven’t already quit). Exercising and adopting a healthy diet can also help. Speak with your healthcare provider about pulmonary rehabilitation—a treatment program that utilizes exercise, counseling, nutrition and breathing techniques to help people with respiratory illnesses improve lung function, manage symptoms and improve quality of life.