Nearly 100 million Chinese adults have COPD, but most don’t know they do, a study reported.
Heavy air pollution and high smoking rates are two likely reasons for the high rate, said researchers, who added that efforts to prevent and diagnose the disease early should be a health priority.
The study, “Prevalence and risk factors of chronic obstructive pulmonary disease in China (the China Pulmonary Health [CPH] study): a national cross-sectional study,” was published in the journal The Lancet.
COPD was the third-highest cause of death in China in 2013. In the past few years it has become one of the three most prevalent chronic diseases in the country, after hypertension and diabetes.
Exposure to lung irritants, such as air pollution and cigarette smoke, are known risk factors for COPD. In China, air pollution has reached critical levels, becoming a major health problem. In addition, the proportion of smokers remains high, especially among men.
Researchers used spirometry to examine the lung function of 50,991 adults, aged 20 or older, from different regions of China. They chose different areas so they could obtain a nationally representative sample of the population. It was the largest COPD study across age groups ever done in the country, researchers said
The key finding was that 9 percent of Chinese adults had COPD in 2015, which equated to 999.9 million people.
Importantly, the team found that most people with COPD were unaware of their condition, and the majority had never had a lung function test. Only 2.6 percent were aware of their COPD, and as few as 12 percent had had a lung test.
The COPD rate in men was twice that in women — 11.9 percent versus 5.4 percent. Even among non-smokers, men had a higher rate than women.
Another finding was that the COPD rate increased with age. It was 2.1 percent for those between 20 and 39 years old, but 13.7 percent for those 40 years and older.
In addition, the condition was significantly more common in rural areas. It affected 9.6 percent of the population there, compared with 7.4 percent in urban areas.
Researchers said the factors that increased the risk of COPD included high exposure to smoking and air pollution, chronic cough during childhood, being underweight or overweight, and a parental history of respiratory diseases.
Of note, a higher education level was associated with a lower risk of COPD.
“Our research shows that COPD is highly prevalent in the Chinese adult population. The biggest preventable risk factors for the disease are cigarette smoking and air pollution,” Jiang He, MD, a professor of epidemiology at Tulane University in New Orleans, said in a press release.
“Prevention programs and increased efforts to catch COPD early should be public health priorities in China to reduce COPD-related diseases and deaths,” added He, the senior author of the study.
The team suggested a stop-smoking campaign, better pollution abatement efforts, more use of biomass fuels, and COPD screening in high-risk individuals.