Prognostic value of nutritional depletion in patients with COPD treated by long-term oxygen therapy - Data from the ANTADIR Observatory

Background: An association between weight depletion and mortality has been demonstrated in patients with COPD, but the prognostic influence of malnutrition has not been evaluated in patients with the most severe COPD treated with home long-term oxygen therapy (LTOT). Study objective: To analyze the prognostic value of nutritional depletion in patients with COPD receiving LTOT with respect to survival and hospitalization rate. Design: Analysis of a national database (Observatory of Association Nationale pour le Traitement a Domicile de l'Insuffisance Respiratoire Chronique [ANTADIR]). Setting: The national nonprofit network for home treatment of patients with chronic respiratory insufficiency (ANTADIR) founded in France in the 1980s. Patients: A total of 4,088 patients with a diagnosis of chronic bronchitis or emphysema, FEVI/vital capacity ratio < 60%, Pao(2) < 8 kPa, and treatment with LTOT between 1984 and 1993. Measurements and results: The prevalence of malnutrition, as defined by a body mass index (BMI) < 20, was 23% in men and 30% in women. BMI was significantly correlated with FEV1 and FEV1/VC. The mean follow-up duration was 7.5 years. The 5-year survival rates were 24%, 34%, 44%, and 59%, respectively, for patients with BMIs < 20, 20 to 24, 25 to 29, and greater than or equal to 30. Multivariate analysis using the Cox model demonstrated that the effect of BMI on survival was independent of age, FEV1, Pao2, and sex. Lower BMI was the most powerful predictor of duration and rate of hospitalization, independently of blood gas levels and respiratory function. The mean (+/-SD) annual time spent in the hospital was 29.6+/-40.4 days for patients with a BMI < 20 vs 17.5+/-30.1 days for patients with a BMI > 30. Conclusion: This study showed that nutritional depletion is an independent risk factor for mortality and hospitalization in patients with COPD receiving LTOT. The best prognosis was observed in overweight and obese patients.