Relationship between respiratory function assessed by spirometry and mild cognitive impairment among...

Aging is a major cause of cognitive dysfunction. It has also been reported that respiratory function may influence cognitive dysfunction. However, few studies have examined the relationship between cognitive function and respiratory function among community-dwelling older adults. This study aims to determine the relationship between respiratory function, assessed using spirometry, and mild cognitive impairment (MCI) in community-dwelling older adults.

This study included 419 participants aged 73 ± 1 years and 348 participants aged 83 ± 1 years from the SONIC cohort study (Septuagenarians Octogenarians Nonagenarians Investigation with Centenarians Study). Respiratory function was evaluated using %Vital Capacity (%VC), Forced Expiratory Volume 1 s (FEV₁)/Forced Vital Capacity (FVC), and %Peak Expiratory Flow (%PEF). Airflow-limitation presence and stages were classified using FEV₁/FVC. Cognitive function and MCI were assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J).

The MoCA-J score exhibited a declining trend as the airflow-limitation stage increased among study participants in the 83 ± 1 age group. The presence of airflow limitation was associated with MCI in the 83 ± 1 age group. Among the indicators of each respiratory function, low %PEF was found to be associated with an increased rate of MCI. Furthermore, low %VC has also been suggested to be associated with an increased rate of MCI in the 83 ± 1 age female group.

Advanced airflow-limitation stages may exacerbate cognitive dysfunction in community-dwelling older adults. The presence of airflow limitation and low %VC may also be associated with cognitive dysfunction in older women. Consequently, reduced respiratory function may potentially be associated with MCI in community-dwelling older adults. Geriatr Gerontol Int 2024; 24: 1001-1007.