Chronic obstructive pulmonary disease (COPD) in US adults aged 20 to 50 years, though rare, significantly heightens the risk of all-cause mortality, according to results from a recent study published in BMJ Respiratory Research.
Little research has been done on the characteristics of patients aged 20 to 50 years of age who have COPD and their prognoses. To determine the prevalence, risk factors, and mortality of COPD in this population, researchers conducted a population-based retrospective cohort study based on the US National Health and Nutrition Examination Survey (NHANES).
The researchers analyzed NHANES data from participants between the ages of 20 and 50 years at baseline who completed pulmonary function testing (77.8% male; 83.0% non-Hispanic White). A post-bronchodilator forced expiratory volume in one second/forced vital capacity ratio (FEV1/FVC) of less than 0.7 was used to identify COPD in those aged 20-50 years. The sample weight and Taylor Linearization Procedures were utilized to estimate the prevalence and baseline characteristics accurately. Risk factors were assessed using a weighted logistic regression model, while the mortality risk was calculated using the propensity score method and Cox proportional hazard models. Participants were followed until December 31, 2019.
The cohort used for analysis included nearly 8000 individuals, including 102 men with COPD, 3758 men without COPD, 28 women with COPD, and 3896 women without COPD.
Male, race (non-Hispanic black and non-Hispanic white) and smoking were independent risk factors for COPD in young people. Young COPD had a higher risk of all-cause mortality.
The overall prevalence of COPD in individuals aged 20 to 50 years included in NHANES from 2007 through 2012 was 1.64%. Investigators found that the prevalence rate increased with age and was higher in men vs women (2.59% vs 0.72%; P <.001). Other risk factors for COPD in this population included being older than 35 years of age; being non-Hispanic Black or non-Hispanic White; currently smoking; exposure to smoking (ie, passive smoking); occupational exposures; and previous diagnosis of emphysema, cancer, shortness of breath, chronic cough, chronic sputum, and wheezing. A higher risk of all-cause mortality was found in individuals with COPD aged 20 to 50 years vs matched control participants without COPD (hazard ratio, 3.31; P =.0004).
Study limitations included a lack of data on longitudinal changes in pulmonary function in the COPD cohort studied; limited information on patient history, which precluded analysis of the relationship between risk factors and COPD; and lack of analysis of acute exacerbations.
The study authors concluded that “Male, race (non-Hispanic black and non-Hispanic white) and smoking were independent risk factors for COPD in young people. Young COPD had a higher risk of all-cause mortality.” Because of this, early detection and intervention for COPD individuals aged 20 to 50 years is important and merits further research, said the investigators.