Association of impaired lung function with dementia and cognitive function: The AGES-Reykjavik Study

• Published in: Cerebral circulation - cognition and behavior 2024, Vol.6, p.100348, Article 100348
• Main Authors: Imahori, Yume, Mbangdadji, Djass, Gudnason, Vilmundur, Qiu, Chengxuan, Launer, Lenore
• Format: Article
• Language: English
• ISSN: 2666-2450; 2666-2450
• DOI: 10.1016/j.cccb.2024.100348

Emerging evidence has linked impaired lung function with dementia and cognitive decline. However, unlike obstructive lung impairment (e.g., chronic obstructive pulmonary disease (COPD), asthma), the association of preserved ratio impaired spirometry (PRISm) with cognitive function remains under-investigated. We aimed to investigate the association of COPD and PRISm with dementia and cognitive function in older adults. This population-based study involved 2421 dementia-free participants (age >65 years, mean age 76.3, 57% female) derived from the Age, Gene/Environment Susceptibility (AGES)- Reykjavik Study who had spirometry data assessed at baseline (2002-2006) and were re-examined in the follow-up (2007-2011). Lung function was categorized as normal, PRISm, and COPD based on spirometry data. Incident dementia cases occurred during the follow-up period through 2015 were ascertained using study examination, nursing home records, hospital records or vital statistic data (median follow-up time=10.3 years; no. of incident dementia cases=650). The association between baseline lung function and incident dementia was investigated using the Cox regression and Fine-Grey competing death risk models. In a subsample (n=1363). We used the linear regression models to investigate baseline lung function in association with function of cognitive domains assessed at follow-up (2007-2011). PRISm (vs. normal lung function) was associated with a multivariable-adjusted hazard ratio of 1.59 (95%CI 1.28-1.97) for incident dementia. The association remained significant even after considering the competing risk due to death. In subsample analysis, baseline PRISm was significantly associated with lower scores of executive function and processing speed at follow-up, while COPD was associated with a lower score of processing speed (p