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Introduction: The number of older people with cognitive impairment is estimated to triple by 2050, posing a high socioeconomic burden worldwide. Cognitive health is among the major factors relevant to preserving the quality of life as it allows older people to maintain sense of purpose and ability to live independently. According to some previous research, impaired lung function might be associated with cognitive decline in older age. However, most of the previous epidemiological studies relied on a cross-sectional design that does not allow for observing the dynamic nature of cognitive aging. To address these gaps, we used data from the Survey of Health, Ageing and Retirement in Europe (SHARE), which provides an opportunity for examining the longitudinal associations between baseline pulmonary function and the trajectories of cognitive functions among older adults from 14 European countries, spanning 14 years. Methods: The analytic sample included N = 32,111 older adults (M age = 65.23 years at baseline). The cognitive functions were measured repeatedly across six waves in three domains: verbal fluency, episodic memory, and numeracy. The main outcome was modeled as a latent factor with the cognitive measures as indicators. Our main predictor of interest was peak expiratory flow (PEF), measured by spirometry. All analyses were adjusted for age, sex, alcohol use, smoking status, BMI, education level, and history of cardiovascular disease. These covariates were measured at baseline (Wave 1). The data were analyzed in a three-level accelerated longitudinal design structured on individual ages. Separate models were also estimated for each indicator of cognitive function. Results: The results showed that cognitive ability declined linearly with age (B = -0.09 per year, p < .001), and this was also found for each cognitive measure. PEF was positively associated with baseline cognitive ability above and beyond other covariates (B = 0.97 per quartile, p < .001), and this association was confirmed for each cognitive function. The cognitive decline was steeper for females (B =-0.03, p < .001), smokers (B =-0.04, p < .001), and older people (B =-0.01 per year, p < .001), yet no other covariate significantly affected the rate of decline. Conclusion: Impaired lung function was found to be an independent predictor of cognitive ability, and this was found regardless of the type of cognitive function. The results highlight the importance of maintaining a healthy pulmonary system to reverse or halt the cognitive decline in the aging population and the suitability of spirometry for assessing the risk of cognitive decline. Funding: European Union’s Horizon 2020 research and innovation programme: No 857487 and The NPO „Systemic Risk Institute“ (Programme EXCELES, No. LX22NPO5101).
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