Associated Factors and Characteristics of PRISm: a Study Based on Community Residents

Background 20%-30% of individuals with Preserved Ratio Impaired Spirometry (PRISm) will develop chronic obstructive pulmonary disease (COPD). However studies on characteristics of PRISm in China remain limited. Objective To analyze factors associated with PRISm, and to explore the difference in the distribution of risk factors between individuals with PRISm and COPD. Methods This study was conducted as part of health management in Shanghai communities. Elderly individuals over 60 years old from 11 communities in Putuo District, Shanghai, who participated COPD screening from July 2022 to June 2023, were surveyed and underwent lung function tests. A total of 876 participants were initially included, but 141 were excluded due to incomplete questionnaire information or poor lung function test quality, resulting in 735 valid subjects. According to the "Guidelines for Graded Diagnosis and Treatment of Chronic Obstructive Pulmonary Disease" and GOLD 2024, participants were classified into three subgroups based on post-bronchodilator lung function: COPD group (FEV1/FVC < 70%), PRISm group (FEV1%Pred< 80% and FEV1/FVC≥ 70%), and normal lung function group. Multivariate Logistic regression analyses were conducted to identify factors associated with COPD and PRISm, using normal lung function as the control. Results A total of 735 individuals aged 60~81 were included. COPD and PRISm were observed in 157 (21.36%) and 113 (15.37%) participants, respectively. COPD-SQ scores were highest in the COPD group (20.46±4.53), followed by the PRISm group (19.04±4.41) and lowest in the normal lung function group (18.03±4.26) with statistically significant differences (P<0.001). Univariate analysis showed that the PRISm group had higher proportions of males, smokers, individuals with frequent wheezing, chronic bronchitis and hypertension compared to the normal lung function group (P<0.05). Compared to COPD patients, the PRISm group had lower proportions of males, smokers, individuals with symptoms of wheezing or coughing after exercise, and those with a history of emphysema, but a higher prevalence of hypertension (P<0.05). Multivariable Logistic regression analyses revealed that increasing age, male gender, higher smoking levels, insufficient physical activity, frequent wheezing, wheezing or coughing after exercise, family history of COPD or bronchial asthma, and history of bronchial asthma or emphysema were associated with COPD (P<0.05). In contrast, higher smoking levels, insufficient physical activity, frequent wheezing, chronic bronchitis, and hypertension were associated with PRISm (P<0.05) . Conclusion PRISm is a high-risk state between COPD and normal lung function, sharing similar associated factors with COPD such as age, smoking states, physical activity, symptoms and comorbidities. However, the COPD-SQ score and the predictive performance of multivariable logistic regression model for lung function status were significantly lower for PRISm compared to COPD. Hypertension was an independent associated factor for PRISm, but not for COPD, suggesting a potential risk of cardiovascular disease independent of COPD. Further research is warranted to verify the role of PRISm characteristics in disease progression.