Previous studies have reported an association between the impairment of cognitive performance and lung diseases. However, whether obstructive or restrictive lung diseases have an impact on cognitive function is still inconclusive. We aimed to investigate the association between cognitive function and obstructive or restrictive lung diseases in Taiwanese adults using the Mini-Mental State Examination (MMSE). In this study, we used data from the Taiwan Biobank. Cognitive function was evaluated using the MMSE. Spirometry measurements of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were obtained to assess lung function. Participants were classified into three groups according to lung function, namely, normal, restrictive, and obstructive lung function. In total, 683 patients enrolled, of whom 357 participants had normal lung function (52.3%), 95 had restrictive lung function (13.9%), and 231 had obstructive lung function (33.8%). Compared to the normal lung function group, the obstructive lung function group was associated with a higher percentage of cognitive impairment (MMSE < 24). In multivariable analysis, a low MMSE score was significantly associated with low FVC, low FEV1, and low FEV1/FVC. Furthermore, a low MMSE score was significantly associated with low FEV1 in the participants with FEV1/FVC < 70%, whereas MMSE was not significantly associated with FVC in the participants with FEV1/FVC ≥ 70%. Our results showed that a low MMSE score was associated with low FEV1, low FVC and low FEV1/FVC. Furthermore, a low MMSE score was associated with obstructive lung diseases but not with restrictive lung diseases.
Keywords: Mini-Mental State Examination; cognitive decline; obstructive and restrictive lung function.