COPD therapy boosts heart disease risk

Researchers from Sweden say obstructive pulmonary disease (COPD) patients on long-term oxygen therapy or LTOT may face an increased risk of death from cardiovascular disease and other non-respiratory ailments.

Chronic Obstructive Pulmonary Disease, or COPD, refers to a group of diseases that cause airflow blockage and breathing-related problems.  It includes emphysema, chronic bronchitis, and in some cases asthma.

The researchers recruited 7,628 patients who started LTOT for COPD between 1987 and 2004 and followed them for an average of 1.7 years.

The results showed the risk of death for cardiovascular disease increased by 61.5 percent between 1987 and 2004 due to both circulatory disease and digestive organ disease, while the risk of death decreased annually for both respiratory disease and lung cancer.

Previous studies have shown that the risk of death from cardiovascular disease will increase with age.

"In oxygen-dependent COPD, mortality has decreased for respiratory disease and increased for non-respiratory causes, such as cardiovascular disease," said Dr. Ekström, respiratory medicine physician and researcher, Blekinge Hospital, Karlskrona, Sweden. "This supports the importance of optimized diagnostics and treatment of coexisting diseases and conditions to improve survival in severe COPD."

Shift in mortality may be attributable to an increase in the age of patients starting LTOT, which may be linked to reduction of smoking in Sweden.

"Tobacco exposure has decreased overall in Sweden, resulting in a delay in the decline of lung function, which means patients are generally older when they require LTOT," Ekström added. 

In the United States, tobacco use is a key factor in the development and progression of COPD.

Asthma, exposure to air pollutants in the home and workplace, genetic factors, and respiratory infections also play a role.

"Physicians who treat COPD with LTOT need to be aware of these shifts and to monitor for other conditions that may influence the risk of death in these patients" Dr. Ekström suggested.

Stephen Lau and editing by Aimee Keenan-Greene