Background: To examine the prevalence and characteristics of PRISm among Chinese individuals, as well as its association with future mortality and cardiovascular (CVD) outcomes. Methods: This was a substudy of the Prospective Urban Rural Epidemiology (PURE) study, which recruited 40,279 individuals aged 35-70 years from 115 urban and rural communities in 12 provinces across China between 2005 and 2009. At baseline, participants were categorized into subgroups based on PRISm, airflow obstruction (AO), and normal spirometry. Follow-up was conducted every three years to obtain information on major cardiovascular events and mortality. Cox frailty proportional hazard regression was used to estimate the hazard ratios (HR) and 95% confidence interval (95%CI). Results: The baseline prevalence rates of PRISm, AO and normal spirometry were 29.3%, 8.5%, and 62.2% respectively. Over a median follow-up period of 11.9 years, 2,214 deaths, with 773 attributed to CVD, and 3,507 major CVD events were observed. After adjusting for potential confounders, individuals with PRISm, comparing to those with normal spirometry, exhibited significantly elevated risks of all-cause mortality (HR 1.42, 95%CI [1.29, 1.58]), CVD mortality (HR 1.35, 95%CI [1.14, 1.60]), major CVD events (HR 1.16, 95%CI [1.07, 1.25]), myocardial infarction (HR 1.34, 95%CI [1.15,1.56]), and heart failure (HR 2.02, 95%CI [1.46, 2.79]). Conclusions: PRISm, a frequently observed result in spirometry among the general Chinese population, exhibits a substantial association with long-term all-cause mortality, CVD mortality, major CVD events. Further investigation is warranted to comprehensively compared the underlying pathophysiologic connection between PRISm and CVD as well as mortality.

The authors have declared no competing interest.

The PURE study is an investigator-initiated study that is funded by the Population Health Research Institute (PHRI), Hamilton Health Sciences Research Institute (HHSRI), and the Canadian Institutes of Health Research, Heart and Stroke Foundation of Ontario. The PURE-AIR study is funded by Canadian Institutes for Health Research (CIHR; grant 136893) and by the Office of the Director, National Institutes of Health (NIH; award DP5OD019850) through unrestricted grants from several pharmaceutical companies and additional contributions from various national or local organizations in participating countries. PURE-China study is partly supported by the National Centre for Cardiovascular Diseases, the ThinkTank Research Centre for Health Development, and the National Clinical Research Centre for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences (Grant No. NCRC2020002 and NCRC2023-GSP-GG-36).

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The study protocol was approved by the ethics committees of the Fuwai Hospital of Chinese Academy of Medical Sciences and Beijing Hypertension League Institute.

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