Speaker- Na Young Kim
Unlike the diagnosis of Chronic Obstructive Pulmonary Disease (COPD), its severity is typically assessed using forced expiratory volume in 1 second (FEV1); however, this measurement has limitations due to factors such as obesity, genetics, and lung volume variations. As a result, alternatives may be necessary. Recently, a COPD gene group proposed a new severity category, known as the Staging Airflow Obstruction by Ratio (STAR) classification, based on the FEV1/Forced vital capacity (FVC) ratio, which offers a more uniform prediction of mortality compared to the Global Initiative for Obstructive Lung Disease (GOLD) classification. It was noted that rapid decline in FEV1 is linked to increased hospitalization and mortality, yet there is limited research on FEV1/FVC decline. One study in the general population indicated that a decreased FEV1/FVC ratio was associated with the development of obstructive lung disease and higher mortality rates.
Independent risk factors associated with a rapid decline in the FEV1/FVC sub-ratio was assessed. It was a nested case-control study involving COPD patients. Baseline variables were collected, and changes in symptoms and lung function were monitored over three years. Patients with the most significant negative changes in the FEV1/FVC ratio, determined by quartiles, were classified as rapid decliners.
The median age of participants was 68, with a predominance of male patients. Rapid decliners exhibited lower Body Mass Index (BMI) and a higher prevalence of current smoking. There were no significant differences in comorbidities, history of exacerbations, symptoms, or treatments between rapid and non-rapid decliners. At baseline, rapid decliners had higher FEV1, a higher FEV1/FVC ratio, and fewer patients in STAR stage 4, but no differences were observed in FVC or diffusing capacity of the lungs for carbon monoxide (DLCO). The analysis of clinical parameters showed that rapid FEV1/FVC decline was not linked to the annual exacerbation rate but was associated with symptom worsening and FEV1 decline. Over the three-year tracking period, the use of long-acting beta2 agonists/ long-acting muscarinic antagonists (LABA/LAMA) in non-rapid decliners increased. Independent risk factors for rapid FEV1/FVC decline included low BMI, current smoking, symptom worsening, low STAR stage, rapid FEV1 decline, and the lack of initiation of dual bronchodilators. In a subgroup of patients whose symptoms deteriorated beyond the minimal clinically important difference, continued use of dual bronchodilators was associated with a lower risk of rapid decline.
Specific risk factors contributed to the rapid decline in the FEV1/FVC ratio. Notably, patients who failed to consistently use LABA/LAMA despite worsening symptoms were more prevalent among the rapid FEV1/FVC decliners.
The potential role of aging in the population was studied, questioning whether patients experienced accelerated aging. It was noted that two major risk factors emerged: low body mass index and current smoking, with the latter potentially influencing the acceleration of aging. However, there were no significant differences in aging between the two groups, suggesting that accelerated aging was not a determining factor. Additionally, the impact of exacerbations on lung function came as an issue. Since exacerbations resulted in reductions in both FEV1 and FVC, patients could be classified as non-rapid decliners despite experiencing exacerbations. Consequently, the exacerbation rates were found to be similar between the two groups, as both showed reductions in FEV1 and FVC during these events.
European Respiratory Society Congress 2024, 7–11 September, Vienna, Austria
