BMC Geriatrics (Oct 2024)

The association between preserved ratio impaired spirometry (PRISm) and cognitive function among American older adults: the mediating role of systolic blood pressure

  • Tao Ouyang,
  • Jiajia Zhang,
  • Yichen Tang,
  • Qi Yang

DOI
https://doi.org/10.1186/s12877-024-05349-8
Journal volume & issue
Vol. 24, no. 1
pp. 1 – 10

Abstract

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Abstract Background Recent studies have drawn attention to the association between preserved ratio impaired spirometry (PRISm) and cognitive function decline. High systolic blood pressure (SBP) is a known risk factor for both PRISm and dementia. This study aimed to investigate whether elevated SBP may mediate the relationship between PRISm and cognitive function in older adults. Methods This study analyzed 732 participants aged ≥ 60 years who had completed spirometry and cognitive function tests in the National Health and Nutrition Examination Survey (NHANES) 2011–2012. Multivariable linear regression was employed to assess the relationship between PRISm and cognitive function, as measured through the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word Learning sub-test, the Animal Fluency test (AFT), the Digit Symbol Substitution test (DSST), and global cognition tests. All cognitive tests were modeled as z-scores, and global cognition was calculated as the sum of the z-scores of the CERAD, AFT, and DSST. Mediation analyses were conducted to test the mediating effect of SBP on the association between PRISm and cognitive function. Results Participants with PRISm had lower AFT (β = -0.300; 95% confidence interval [CI] = -0.479 to -0.122; p = 0.001), DSST (β = -0.157; 95% CI = -0.309 to -0.004; p = 0.044), and global cognition scores (β = -0.211; 95% CI = -0.369 to -0.053; p = 0.009) than those with normal spirometry, after adjusting for all potential confounders. SBP was considerably associated with AFT (β = -0.084; 95% CI = -0.162 to -0.005; p = 0.038) and DSST (β = -0.132; 95% CI = -0.207 to -0.057; p < 0.001), mediating 7.9% and 18.0% of the association of PRISm with cognitive function, respectively. Furthermore, SBP mediated 17.1% of the association of PRISm with global cognition. Conclusions The findings suggested the potential role of SBP as a mediator of associations between PRISm and cognitive decline in older adults.

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