Aerobic Activity Linked to Lower Pneumonia and COVID-19 Mortality in Cognitive Impairment

Adults with clinically confirmed mild cognitive impairment or dementia who reported more aerobic physical activity died less often from pneumonia and COVID-19 than their inactive peers, according to a nationwide retrospective cohort study published in GeroScience. The analysis drew on 116,563 people registered with the Korean Dementia Relief Center registry between 2016 and 2021, whose records were linked to health screening data and the national death registry.

The researchers, Seyoung Shin and MinYoung Kim, quantified aerobic physical activity in metabolic-equivalent minutes per week, a unit that captures both the intensity and duration of activity. They used Cox proportional hazards models to estimate adjusted hazard ratios for all-cause mortality and Fine–Gray competing-risk models to estimate subdistribution hazard ratios for cause-specific deaths, accounting for the fact that a person can die of only one cause at a time.

During 400,500 person-years of follow-up, with a mean of 3.4 years per participant, 5,022 people died, or 4.31 percent of the cohort. Compared with inactivity, low, moderate, and high activity levels were each associated with lower all-cause mortality, with adjusted hazard ratios of 0.728, 0.704, and 0.636 respectively, meaning even modest activity was linked to a roughly 27 to 36 percent lower risk of death from any cause.

The cause-specific results pointed most strongly toward respiratory infections. Among the most active participants, pneumonia mortality showed a subdistribution hazard ratio of 0.554 (95 percent confidence interval, 0.437 to 0.702) and COVID-19 mortality a subdistribution hazard ratio of 0.520 (0.368 to 0.735). These point estimates were numerically lower than those observed for ischemic heart disease and cerebrovascular disease, at 0.613 and 0.630, even though cardiovascular disease is a major cause of death in dementia.

Pneumonia mortality was lower across all activity levels after the authors controlled the false discovery rate using the Benjamini–Hochberg procedure across 18 cause-specific comparisons, with q-values of 0.023 or lower. This multiple-comparison control matters because testing many causes of death simultaneously inflates the chance of spurious associations; the pneumonia finding survived that scrutiny.

The authors also reported an E-value of 3.01 for the high-activity–pneumonia association, a sensitivity metric describing how strong an unmeasured confounder would need to be, associated with both the exposure and the outcome, to explain away the observed link. The reported value does not rule out unmeasured confounding.

The study’s central limitation is its observational design. Aerobic physical activity was measured by self-report at screening rather than by repeated objective assessment, and the authors note that activity may also indicate preserved physiological reserve, meaning frailer individuals may both exercise less and die sooner. The findings therefore do not establish causality and require confirmation using repeated, objective activity measurements.

Within those constraints, the practical message is that activity levels were associated with lower mortality in this population even at modest amounts, especially for pneumonia deaths. The authors suggest that achievable activity goals may merit prospective evaluation as part of supportive care for adults with cognitive impairment, a step that would require intervention studies before any clinical recommendations can be made.

Subject of Research: Association between aerobic physical activity and cause-specific mortality in adults with mild cognitive impairment or dementia

Article Title: Aerobic physical activity is associated with lower pneumonia and COVID-19 mortality in adults with cognitive impairment

Article References: Shin, S., & Kim, M. (2026). Aerobic physical activity is associated with lower pneumonia and COVID-19 mortality in adults with cognitive impairment. GeroScience. https://doi.org/10.1007/s11357-026-02596-y

Image Credits: AI Generated

DOI: 10.1007/s11357-026-02596-y

Keywords: aerobic physical activity, cognitive impairment, dementia, pneumonia mortality, COVID-19 mortality, cohort study, GeroScience, all-cause mortality, Fine–Gray model, E-value, physiological reserve, Korean Dementia Relief Center registry