Mortality in Oxygen-Dependent Chronic Obstructive Pulmonary Disease and Possibilities for Pharmacological Interventions

Sammanfattning: Background Chronic obstructive pulmonary disease (COPD) is a major and rising cause of mortality worldwide, especially in women. Patients with chronic hypoxia owing to COPD are treated with long-term oxygen therapy (LTOT) but have high morbidity and mortality. Knowledge is limited on sex-related differences and time trends in mortality, effects of comorbidity on mortality and whether cardiovascular drugs affects mortality in these patients. Aims In patients with oxygen-dependent COPD, to estimate: • Sex-related differences in excess mortality for different causes of death, as compared with the general population (paper I). • Time trends in overall and cause-specific mortality (paper II). • Differences in comorbidity between men and women and whether comorbidity contributes to sex-related differences in mortality (paper III). • Effects of cardiovascular drugs on mortality (paper IV). Study Populations Patients starting LTOT for COPD in Sweden 1987 - 2004 (papers I and II), 1992 - 2008 (paper III), and Oct 2005 – Jun 2009 (paper IV) in the national Swedevox Register. Results and conclusions Women live longer than men after starting LTOT, but have higher excess mortality than men when compared with the general population, for all-cause mortality, and for cancer, respiratory, and cardiovascular disease. Comorbidity differs between men and women but does not explain the better survival for women after starting LTOT. Over time, mortality has shifted to more non-respiratory causes of death, and excess mortality has increased. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, antiplatelet drugs, and statins may improve survival, whereas beta blockers may decrease survival in oxygen-dependent COPD.