The role obesity plays in COPD is of important significance. Although obesity is not a risk factor for chronic respiratory diseases like COPD, there is clinical evidence that suggests an increasing, influential relationship between the two. Obesity lends itself to a worsening of COPD symptoms, and a decrease in both exercise tolerance and quality of life. Weight loss, however, can provide significant, symptomatic improvement. So why is the link between obesity and COPD on the rise?
To date, COPD is the third leading cause of death in the United States, behind only heart disease and cancer. With COPD mortality rates on the rise, the number of patients who present themselves to the health care system with COPD is also increasing. Along with an increase in sedentary lifestyles and air pollution, it is not difficult to see why these two health problems would coexist, as well as pose major challenges to their prevention.
Definition of Obesity
Obesity can be defined in relation to body mass index (BMI), which describes a relationship between weight and height. The following guidelines will help you determine if you are overweight or obese, according to a standard BMI chart.
- Underweight: >18.5
- Normal: 18.5 to 24.9
- Overweight: 25 to 29.9
- Obese: 30.0 or 39.9
- Morbid obesity: 40 and higher
With a BMI of 25 or greater, more than 1 billion people across the globe are either overweight or obese. Obesity is a significant risk factor for heart disease, diabetes, rheumatoid arthritis and cancer. In 2000, obesity was a major cause of morbidity for approximately 400,000 people in the United States, contributing to about 7% of all health care costs. With these statistics in mind, it is important to determine the effects that obesity has on lung function.
The Effects of Obesity on Your Lungs
Ventilation refers to breathing, or the inhalation and exhalation of air from the lungs. An overabundance of fat tissue, which occurs from obesity, impairs the breathing process in both adults and children. Moreover, an increased BMI is also associated with a host of other respiratory problems, including a reduction in the following pulmonary function tests:
- Forced expiratory volume in one second (FEV1)
- Forced vital capacity (FVC)
- Total lung capacity
- Functional residual capacity
- Expiratory reserve volume
Since carrying around excess weight increases the work of breathing, there is a direct association between obesity and shortness of breath, or dyspnea, which is also recognized as the hallmark symptom of COPD. When COPD is coupled with obesity, COPD symptoms, namely dyspnea, worsen.
Obesity is also strongly associated with a decrease in exercise tolerance. Along with health problems associated with inactivity, being unable to exercise can severely impact quality of life.
Obesity and COPD
Obesity frequently coexists with COPD, since both conditions are common in the Western population. This may be attributed to people with COPD leading more sedentary lifestyles, which is why implementing an exercise program is so important. Given the fact that being overweight and obese makes it more difficult to exercise, though, how does an exercise program fit in to the picture?
Success Strategies for COPD Patients Who Are Obese
Weight reduction, if you are overweight or obese, is the optimal health strategy for patients who suffer from COPD. This can be done through a combination of diet, an increase in physical activity and (sometimes) medication. There are limited study results and recommendations about weight loss strategies for people with chronic respiratory illnesses, such as COPD, however. Many times, weight loss is ineffective, because patients with COPD are inactive and don't comply with recommended exercise programs.
Weight reduction can help reduce dyspnea, increase exercise tolerance and improve your quality of life. According to About.com's Weight Loss Guide, additional health benefits of weight loss include:
- An increased energy level
- Reduction of cholesterol levels
- Reduction in blood pressure
- Reduces aches and pains
- Improves mobility
- Improves sleep
- Prevents angina, or chest pain caused by decreased oxygen to the heart
- Decreases your risk of sudden death from heart disease or stroke
- Helps to prevent type 2 diabetes
- Improves blood sugar levels
How to Lose Weight SuccessfullyLosing weight can be challenging, especially if you have COPD. The benefits of weight loss are numerous and paramount to successful COPD treatment. Here are some guidelines to follow in order to lose weight successfully:
COPD Fact Sheet. (2007). American Lung Association. http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=252866.
CMAJ. The Effect of Obesity on Chronic Respiratory Disease: Pathophysiology and Therapeutic Strategies. http://www.cmaj.ca/cgi/content/full/174/9/1293. April 25, 2006 : 174 (9).