Obesity and Mortality in Persons with Obstructive Lung Disease Using Data from the NHANES III
The relationship between obesity and mortality in patients with chronic obstructive pulmonary disease (COPD) was a component of the most recent large National Health and Nutrition Examination Survey (NHANES III), reported here by Jordan and Mann. From a cohort of 33,994 participants, mortality was reviewed in relation to body mass index of patients with COPD. As expected, mortality was high in patients who were significantly underweight (body mass index less than 18.5 kg/m2; hazard ratio 2.42) compared with normal weight patients who had COPD. Also seen was a significant mortality risk for obese patients (body mass index greater than 40 kg/m2). The hazard ratios for obese patients were 5.78 for any respiratory mortality and 13.69 for COPD mortality. This large mortality risk for obesity in COPD was independent of its well-known risk for all-cause mortality.
Increasing rates of obesity and a trend toward increased body weight among all sectors of the US population (eg, age, gender, ethnicity) are causes for concern. The impact of obesity on the incidence of major diseases such as diabetes, hypertension, and cardiovascular disease, to name a few, is well known. The NHANES III survey, which focused on COPD, provides the strongest evidence yet that obesity has a major impact on COPD as well. Although this survey does not provide evidence that respiratory mortality rates will decline if obesity is corrected, attempts to address obesity in patients who have COPD are appropriate.
Now that pulmonary rehabilitation is recognized as an important, if not vital, component of the treatment of COPD, its exploitation in obese patients with COPD becomes rational and even more important. It has been demonstrated that the obese patient with COPD can benefit from pulmonary rehabilitation.[1,2] Similarly, modification of the diet and caloric intake of obese patients with COPD is warranted.