Abstract
Background: Preserved ratio impaired spirometry (PRISm), characterized by the decreased forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) with a preserved FEV1/FVC ratio, is highly prevalent and heterogeneous. We aimed to identify the subtypes of PRISm and examine their differences in clinical characteristics, long-term mortality risks, and longitudinal transition trajectories.Methods: A total of 6,616 eligible subjects were included from the English longitudinal study of aging. Two subtypes of the PRISm were identified as mild PRISm (either of FEV1 and FVC <80% predicted value, FEV1/FVC ≥0.7) and severe PRISm (both FEV1 and FVC <80% predicted values, FEV1/FVC ≥0.7). Normal spirometry was defined as both FEV1 and FVC ≥80% predicted values and FEV1/FVC ≥0.7. Hazard ratios (HRs) and 95% CIs were calculated by the multiple Cox regression models. Longitudinal transition trajectories were described with repeated spirometry data.Results: At baseline, severe PRISm had increased respiratory symptoms, including higher percentages of phlegm, wheezing, dyspnea, chronic bronchitis, and emphysema than mild PRISm. After an average of 7.7 years of follow-up, severe PRISm significantly increased the risks of all-cause mortality (HR=1.91, 95%CI = 1.58–2.31), respiratory mortality (HR = 6.02, 95%CI = 2.83–12.84), and CVD mortality (HR = 2.11, 95%CI = 1.42–3.13) compared with the normal spirometry, but no significantly increased risks were found for mild PRISm. In the two longitudinal transitions, mild PRISm tended to transition toward normal spirometry (40.2 and 54.7%), but severe PRISm tended to maintain the status (42.4 and 30.4%) or transition toward Global Initiative for Chronic Obstructive Lung Disease (GOLD)2–4 (28.3 and 33.9%).Conclusion: Two subtypes of PRISm were identified. Severe PRISm had increased respiratory symptoms, higher mortality risks, and a higher probability of progressing to GOLD2–4 than mild PRISm. These findings provided new evidence for the stratified management of PRISm.
Highlights
Preserved ratio impaired spirometry (PRISm) is characterized by the proportional reductions in the forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) resulting in a normal FEV1/FVC ratio, alternately referred to as the restrictive spirometry pattern [1, 2], Global Initiative for Chronic Obstructive Lung Disease (GOLD)-unclassified [3], or nonspecific pattern [4]
Using the data of the English Longitudinal Study of Aging (ELSA) cohort, we aimed to identify the two subtypes of PRISm, Abbreviations: Body mass index (BMI), body mass index; CI, confidence interval; COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein; CVD, cardiocerebrovascular disease; ELSA, English Longitudinal Study of Aging; GOLD, Global Initiative for Chronic Obstructive Lung Disease; FEV1; forced expiratory volume in 1 s; FVC, forced vital capacity; LLN, lower limit of normal; PF, peak flow; PRISm, Preserved Ratio Impaired Spirometry; SD, standard deviation
Subjects with GOLD2–4 had the lowest means of FEV1(1.42 ± 0.61 L), PF (273.4 ± 127.5 L), the highest percentages of phlegm (35.4%), wheezing (33.8%), dyspnea (26.3%), and chronic bronchitis or emphysema (15.0%)
Summary
Preserved ratio impaired spirometry (PRISm) is characterized by the proportional reductions in the forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) resulting in a normal FEV1/FVC ratio, alternately referred to as the restrictive spirometry pattern [1, 2], Global Initiative for Chronic Obstructive Lung Disease (GOLD)-unclassified [3], or nonspecific pattern [4]. PRISm was defined as FEV1
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
