Obesity increases the risk and progression of chronic obstructive pulmonary disease (COPD), even for people who’ve never smoked before. A team of American and German researchers measured the waists, hips, body mass index (BMI), and physical activity of newly diagnosed COPD cases in the U.S., and published the clear link they found in the Canadian Medical Association Journal.
"We observed a stronger positive relation with abdominal body fat than with total body fat and COPD," Dr. Gundula Behrens, of the Department of Epidemiology and Preventive Medicine at the University of Regensburg in Germany, wrote. "In particular, overweight as measured by BMI (body mass index) emerged as a significant predictor of increased risk of COPD only among those with a large waist circumference."
The 113,279 men and women they looked at, all of whom were between the ages of 50 and 70, did not have COPD, heart disease, or cancer at the beginning of the study. The 10-year follow-up revealed that COPD had developed in 3,648 people. Women who had a waist circumference of 110 centimeters (43.3 inches) and men with a circumference of 118 centimeters (46.4 inches) had a 72 percent increased risk of COPD.
COPD is a lung disease caused by either chronic bronchitis or emphysema, making it very difficult for people to breathe over time. It is the third leading cause of death in America, according to the American Lung Association. There are 6.8 million women diagnosed with chronic bronchitis, which makes them twice as likely to be diagnosed than men, who make up 3.3 million of the affected population.
"Increased local, abdominal, and overall fat depots increase local and systemic inflammation, thus potentially stimulating COPD-related processes in the lung," the authors wrote, according to a press release.
Obesity is a common and serious condition that's present in more than one-third of U.S. citizens — their BMIs are 30 or higher, according to the Centers for Disease Control and Prevention. BMI is not a direct measure of body fat, and knowing this, the researchers also looked at other factors including their amount of physical activity. In addition to waist circumference, other causes of COPD are pollution, smoking, and toxic particles or dust in the work place, which trigger chronic inflammation and difficult-to-heal injury in the lungs.
Those with large hip circumferences, who were also physically active at least five times a week, were 29 percent less likely to develop COPD because of exercise’s ability to reduce inflammation and stress, and enhance healing. In addition, those who were underweight and malnourished experienced inflammation, which is why researchers found that they had a 56 percent increased risk for COPD.
"Our findings suggest that next to smoking cessation and the prevention of smoking initiation, meeting guidelines for body weight, body shape, and physical activity level may represent important individual and public health opportunities to decrease the risk of COPD. Physicians should encourage their patients to adhere to these guidelines as a means of preventing chronic diseases in general and possibly COPD in particular," the authors concluded.
Source: Leitzmann MF, Behrens G, Matthews CE, et al. Body size and physical activity in relation to incidence of chronic obstructive pulmonary disease. Canadian Medical Association Journal. 2014.