COPD Raises Risk of Mortality in Finland, Population Study Finds
COPD linked to higher rate of cardiovascular, respiratory, cancer-related deaths
Chronic obstructive pulmonary disease (COPD) was associated with an increased risk of overall mortality, as well as higher chances of cardiovascular, respiratory, and cancer-associated deaths, in a group of people living in Finland, a recent study has found.
While asthma was also linked to a higher mortality risk over the 18-year study (from 2000 to 2018), having symptoms of both COPD and asthma — a condition known as asthma-COPD overlap (ACO) — wasn’t significantly associated with such a risk.
The study, “Mortality of asthma, COPD, and asthma-COPD overlap during an 18-year follow up,” was published in Respiratory Medicine.
Chronic uncontrolled asthma may be risk factor for COPD
Obstructive lung diseases are a group of disorders that cause airflow blockage and breathing problems. Asthma and COPD both belong to this group of disorders and can cause symptoms like shortness of breath and cough.
Still, they are distinct from one another. While asthma often develops in children with allergies, COPD usually occurs later in life as a result of lung damage, such as that caused by smoking. Chronic uncontrolled asthma may also be a risk factor for the development of COPD, especially if a person also smokes.
About 27% of COPD patients have ACO, a condition in which they exhibit clinical signs of both COPD and asthma.
COPD, asthma, and ACO have all been previously associated with a higher risk of mortality relative to the general population. To learn more about that relationship, researchers examined mortality rates and clinical features among those with asthma, COPD, and ACO in Finland.
Data were obtained from Health 2000, a Finnish national population health survey of adults, conducted from 2000–2001. A total of 5,922 adults, 30 and older, who completed the survey and agreed to undergo a comprehensive clinical examination were included in the analysis.
Of these, 320 (5.4%) had asthma, 151 (2.5%) had COPD, and 99 (1.7%) had ACO. Patients in these groups had a mean age of 56.5, 63.9, and 66.7 years, respectively.
People with asthma were more often women who did not have a history of smoking, but who did have a history of atopic eczema (dry, itchy inflamed skin), conjunctivitis (eye inflammation), or allergic rhinitis (nose inflammation), all of which are consistent with allergies.
In contrast, COPD patients were more often men and current smokers. Asthma and ACO were also associated with cardiovascular disease, and asthma with diabetes.
Participants were followed until the end of 2018 to monitor causes of death. A total of 1,324 deaths were reported over the 18 years of follow-up. Most deaths — 92.2% or a total of 1,221 — were due to natural causes.
Of the people who died, 109 had asthma, 90 had COPD, and 64 had ACO. In final statistical analyses, having asthma or COPD at the study’s start were each significantly associated with death during follow-up.
These analyses were adjusted for potentially influential factors, including sex, age, smoking, educational level, body mass index (a measure of body fat), physical activity, and history of cardiovascular disease, diabetes, and high blood pressure.
Specifically, asthma increased the risk of death by about 1.3 times, while COPD increased the odds by 1.5 times, a risk that was “comparable to those with a major cardiovascular disease or diabetes,” according to the researchers.
Asthma and COPD significantly increase mortality risk
COPD was also associated with greater odds of respiratory (2.3 times higher), cardiovascular (1.5 times higher), and cancer-related (1.9 times higher) deaths.
Asthma was similarly associated with an increased risk of cardiovascular death (1.5 times higher), as well as respiratory death (2.6 times higher).
While ACO did not significantly influence overall mortality risk, ACO patients who also had blood levels of C-reactive protein (an inflammation marker) from 1–2.99 mg/L had a 2.3 times higher risk of death. Respiratory deaths were also about 3.6 times more likely among ACO patients.
“A small number of ACO patients and a small number of total or cardiovascular deaths may explain the lack of association with total or cardiovascular mortality,” the researchers wrote.
Altogether, these findings indicate that asthma and COPD significantly increase the risk of mortality among the general Finnish population.
The team noted, however, that the analysis may be limited by the fact that a low percentage of people who participated in this general health survey had COPD, asthma, or ACO.