WEDNESDAY, Aug. 16, 2017 (HealthDay News) -- Two major chronic lung diseases -- asthma and COPD -- kill nearly 4 million people worldwide annually, a new report finds.
The study calculates that 3.2 million people died in 2015 from COPD (chronic obstructive pulmonary disease) -- a group of lung conditions that includes emphysema and chronic bronchitis, often tied to smoking. Asthma caused another 400,000 deaths, the report found.
While asthma is more common, COPD is much more deadly. And while both conditions can be treated, many people remain undiagnosed or misdiagnosed. In addition, in many countries, treatment -- if it exists at all -- may be at insufficient levels, the research team added.
"Although much of the burden [from these illnesses] is either preventable or treatable with affordable interventions, these diseases have received less attention than other prominent non-communicable diseases like cardiovascular disease, cancer or diabetes," said report lead author Theo Vos, a professor at the University of Washington, in Seattle. He spoke in a news release from The Lancet Respiratory Medicine, which published the study Aug. 16.
Smoking and air pollution are the leading causes of COPD, the study authors noted. The causes of asthma are less certain but are thought to include allergens and smoking.
One expert in respiratory health agreed that both diseases take a heavy, but treatable, toll on health.
"Asthma may be fairly easily controlled and even reversed with medications," noted Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in New York City.
"And while COPD is also treatable , lung damage is permanent and the natural aging process of the lung is the progressive or accelerated loss of alveoli (lung tissue)," he added. "So the decline in lung function is life-long, whereas asthma does not have this issue."
Vos and his team said that, overall, the diseases have become less common and less deadly since 1990 when judged by rates. But absolute case numbers worldwide have gone up because there are more people in the world -- and more elderly people, too.
The researchers found that COPD hit these countries the hardest: India, Lesotho, Nepal and Papua New Guinea. Asthma was an especially high burden in these countries: Afghanistan, Central African Republic, Fiji, Kiribati, Lesotho, Papua New Guinea, and Swaziland.
Speaking in a journal commentary, Onno van Schayck, of Maastricht University in the Netherlands, said that indoor cooking fuels -- "biomass" materials, such wood and coal, for example -- remain a major source of respiratory illness in poorer nations.
The use of these cooking fuels "is one of the greatest causes of air pollution," he said. "Nowadays, more than half of the world's population uses biomass fuel as a primary cooking source, resulting in a high burden of morbidity and mortality. To reduce household air pollution, a switch to cleaner fuels would be desirable. However, this change is not always possible due to financial or logistical constraints, especially in urban slums."
Interventions aimed at replacing smoke-generating cook stoves with cheap, cleaner-burning devices would go a long way toward cutting the burden of asthma and COPD worldwide, van Schayck said.
The U.S. National Heart, Lung, and Blood Institute has more about lung diseases.