Preserved ratio impaired spirometry (PRISm): prognostic, preventable and treatable?

Abstract

Spirometry is a crucial lung function test, which is primarily aimed at identifying airway obstruction in subjects with chronic symptoms of shortness of breath or cough. An obstructive pattern is defined as an impaired ratio of forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) (ie, FEV1/FVC less than the lower limit of normal (LLN)) (figure 1). It may be caused by asthma and/or chronic obstructive pulmonary disease (COPD) and warrants further testing including bronchodilator responsiveness. Spirometry is essential for diagnosing asthma and COPD, but also for monitoring the course of these highly prevalent chronic airway diseases, including the response to treatment, the level of short-term asthma control and the occurrence of long-term clinical remission. However, there is a second spirometric pattern which is important to discern in clinical practice: preserved ratio impaired spirometry (PRISm), defined as a preserved FEV1/FVC ratio but impaired FEV1 (ie, FEV1 less than 80% predicted). Only recently, PRISm has attracted more attention. Figure 1 The main spirometric patterns encompass an obstructive pattern, a normal spirometry and preserved ratio impaired spirometry (PRISm). BMI, body mass index; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; HDL, high-density lipoprotein; LE8: Life’s Essential 8; LLN, lower limit of normal. PRISm, affecting approximately 6%–18% of the adult general population and elicited by multiple conditions, is associated with …