Trajectory of preserved ratio impaired spirometry (PRISm): patterns, predictors, and potential interventions

Preserved ratio impaired spirometry (PRISm), an abnormal spirometry condition characterized by a decreased forced expiratory volume at the first second (FEV 1 ), is recognized as a precursor of chronic obstructive pulmonary disease (COPD). Growing studies demonstrate that PRISm is associated with an increased risk of the development of fixed airflow obstruction (FAO) and cardiovascular mortality. However, there is still a lack of comprehensive understanding of the patterns and predictors of lung function trajectories in PRISm. Furthermore, standardized interventions that can prevent the deterioration of lung function in PRISm remain unclear. The purpose of this narrative review is to examine the natural history of PRISm by summarizing current evidence on its progression over time, key determinants, and modifiable factors, thereby identifying opportunities for early intervention. In this review, three main patterns of PRISm trajectories were reported, including PRISm to normal spirometry, persistent PRISm, and PRISm to FAO. In accordance, several important factors, such as body mass index (BMI), smoking status, baseline lung function values, comorbid respiratory symptoms and various diseases, and PRISm subtypes, were identified as predictors for the transition of PRISm to other lung function status. Additionally, several potential intervention strategies were developed to slow down the decline of lung function in PRISm and reduce PRISm-related mortality, including early screening and regular monitoring, non-pharmacological interventions, pharmacological interventions, and hierarchical management.