Impact of Pneumonia on Cognitive Aging: A Longitudinal Propensity-Matched Cohort Study

Impact of lower-respiratory tract infections on healthcare utilization and mortality in older adults: a Swedish population-based cohort study

BACKGROUND

Lower respiratory tract infections (LRTIs) have an immediate significant impact on morbidity and mortality among older adults. However, the impact following the infectious period of LRTI remains understudied. We aimed to assess the short- to long-term impact of LRTIs on hospitalization, mortality, and healthcare utilization in older adults.

METHODS

Data from the Swedish National Study of Aging and Care in Kungsholmen (SNAC-K) was analyzed, with data from 2001 to 2019 for mortality and 2001-2016 for healthcare utilization. LRTI-exposed participants were identified and matched with LRTI-nonexposed based on sociodemographics, lifestyle factors, and functional and clinical characteristics. Statistical models evaluated post-LRTI hospitalization risk, days of inpatient hospital admissions, healthcare visits, and mortality.

RESULTS

567 LRTIs-exposed participants during the study period and were matched with 1.701 unexposed individuals. LRTI-exposed individuals exhibited increased risk of hospitalization at 1-year (HR 2.14, CI 1.74, 2.63), 3-years (HR 1.74, CI 1.46, 2.07), and 5-years (HR 1.59, CI 1.33, 1.89). They also experienced longer post-LRTI hospital stays (IRR 1.40, CI 1.18, 1.66), more healthcare visits (IRR 1.47, CI 1.26, 1.71), specialist-care visits (IRR 1.46, CI 1.24, 1.73), and hospital admissions (IRR 1.57, CI 1.34, 1.83) compared to nonexposed participants over 16-years of potential follow-up. Additionally, the 19-year risk of mortality was higher among LRTI-exposed participants (HR 1.45, CI 1.24, 1.70). Men exhibited stronger associations with these risks compared to women.

CONCLUSIONS

LRTIs pose both short- and long-term risks for older adults, including increased risks of mortality, hospitalization, and healthcare visits that transpire beyond the acute infection period, although these effects diminish over time. Men exhibit higher risks across these outcomes compared to women. Given the potential preventability of LRTIs, further public health measures to mitigate infection risk are warranted.

Associations of Lung Function Decline with Risks of Cognitive Impairment and Dementia: A Meta-Analysis and Systematic Review

BACKGROUND

There are controversies surrounding the effects of lung function decline on cognitive impairment and dementia.

OBJECTIVE

We conducted a meta-analysis and systematic review to explore the associations of lung function decline with the risks of cognitive impairment and dementia.

METHODS

The PubMed, EMBASE, and the Cochrane Library were searched to identify prospective studies published from database inception through January 10, 2023. We pooled relative risk (RR) and 95% confidence intervals (CI) using random-effects models. The Egger test, funnel plots, meta-regression, sensitivity, and subgroup analyses were conducted to detect publication bias and investigate the source of heterogeneity.

RESULTS

Thirty-three articles with a total of 8,816,992 participants were subjected to meta-analysis. Poorer pulmonary function was associated with an increased risk of dementia (FEV: RR = 1.25 [95% CI, 1.17-1.33]; FVC: RR = 1.40 [95% CI, 1.16-1.69]; PEF: RR = 1.84 [95% CI, 1.37-2.46]). The results of the subgroup analyses were similar to the primary results. Individuals with lung diseases had a higher combined risk of dementia and cognitive impairment (RR = 1.39 [95% CI, 1.20-1.61]). Lung disease conferred an elevated risk of cognitive impairment (RR = 1.37 [95% CI, 1.14-1.65]). The relationship between lung disease and an increased risk of dementia was only shown in total study participants (RR = 1.32 [95% CI, 1.11-1.57]), but not in the participants with Alzheimer's disease (RR = 1.39 [95% CI, 1.00-1.93]) or vascular dementia (RR = 2.11 [95% CI, 0.57-7.83]).

CONCLUSION

Lung function decline was significantly associated with higher risks of cognitive impairment and dementia. These findings might provide implications for the prevention of cognitive disorders and the promotion of brain health.