Body mass index and prognosis in patients hospitalized with acute exacerbation of chronic obstructive pulmonary disease
Lainscak Mitja1 
von Haehling Stephan3 
Doehner Wolfram3 
Sarc Irena2 
Jeric Tina2 
Ziherl Kristina2 
Kosnik Mitja2 
Anker Stefan D.3 
[1] Division of Cardiology, University Clinic of Respiratory and Allergic Diseases Golnik, Golnik;University Clinic of Respiratory and Allergic Diseases, Golnik;Applied Cachexia Research, Department of Cardiology, Charité Medical School, Berlin
Nutritional status, weight loss and cachexia have important prognostic implications in patients with chronic obstructive pulmonary disease (COPD). Body mass index (BMI) has been implicated in COPD risk assessment, but information is mostly limited to composite scores or to patients with stable disease. We aimed to analyse the association between BMI and mortality in acute exacerbation of COPD.
Methods
This retrospective survey included 968 patients hospitalized due to acute exacerbation of COPD at the University Clinic Golnik from February 2002 to June 2007. Vital status was ascertained with Central Population Registry, and database was censored on November 1, 2008.
Results
Median BMI was 25.08 kg/m2 (interquartile range, 21.55–29.05 kg/m2) and 210 patients (22%) had BMI < 21 kg/m2. During median follow-up of 3.26 years (1.79–4.76 years), 430 patients (44%) died. Lowest mortality was found for BMI 25.09–29.05 kg/m2. When divided per BMI decile, mortality was lowest for BMI 25.09–26.56 kg/m2 (33%). In univariate analysis, BMI per quartile and BMI per unit increase were predictive for all-cause mortality. In an adjusted model, BMI per 1 kg/m2 unit increase was associated with 5% less chance of death (hazard ratio 0.95, 95% confidence interval 0.93–0.97).
Conclusions
Low BMI < 21 kg/m2 is frequent in patients hospitalized due to acute exacerbation of COPD. Higher BMI was independently predictive of better long-term survival. A better outcome in obese patients compared to normal weight is in contrast to primary prevention data but concurs with observations of an obesity paradox in other cardiovascular diseases.
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