BMI and oral glucocorticoids as predictors of prognosis in COPD patients on long-term oxygen therapy

Aims: The objectives of the study were to determine whether body mass index (BMI), and oral corticosteroid use predict survival and hospitalization in hypoxaemic chronic obstructive pulmonary disease (COPD) patients. Methods: The study was a prospective cohort study with analysis of a nationwide database (Danish Oxygen Register). We studied survival and hospitalization in 221 hypoxaemic COPD patients who were on long-term oxygen therapy (LTOT). Results: Low BMI was strongly associated with high mortality (P 25 kg/mi 2 ), RR = 3.8 (1.4- 10.5), P = 0.011. Whereas BMI had no influence on risk of any hospitalization in patients using oral steroids, high BMI was independently associated with reduced risk of any hospitalization in patients without oral steroids [the RR of any hospitalization for each 1 kg/M 2 increase in BMI was 0.94 (CI: 0.90-0.99), P = 0.009]. Overall, the use of oral steroids was associated with increased risk of any hospitalization, RR = 1.7 (1.2-2.4), P = 0.002. This increase was especially pronounced in the group with BMI above 25 kg/M 2 , where steroid treatment increased the risk of any hospitalization with RR = 3.6 (1.5-8.7), P = 0.005. Conclusions: In hypoxaemic patients on LTOT, low BMI is an independent risk factor of death and any hospitalization. Maintenance treatment with oral corticosteroids is associated with increased mortality and hospitalization in COPD patients with high BMI. Our findings suggest that loss of body weight should be avoided, and that oral corticosteroids should be used cautiously in patients on LTOT-especially those with high BMI. Further research on the role of changes in body composition as a prognostic factor is needed.