Identifying Cognitive Profiles and Determinants of Cognitive Superaging Among Older Adults
| dc.contributor.author | Khan, Maham | en |
| dc.contributor.committeechair | Sands, Laura Prouty | en |
| dc.contributor.committeechair | Katz, Benjamin D. | en |
| dc.contributor.committeemember | Davy, Kevin P. | en |
| dc.contributor.committeemember | Savla, Jyoti Shital | en |
| dc.contributor.department | Adult Learning and Human Resource Development | en |
| dc.date.accessioned | 2025-12-12T09:00:40Z | en |
| dc.date.available | 2025-12-12T09:00:40Z | en |
| dc.date.issued | 2025-12-11 | en |
| dc.description.abstract | Cognitive aging among older adults is heterogeneous and does not follow a single trajectory. This study used a person-centered approach to identify cognitive profiles, specifically cognitive superagers, among United States adults aged 75 and older and to quantify transitions between cognitive profiles across three waves of the Health and Retirement Study in 2012, 2016, and 2020. Five indicators of memory, attention, language fluency, and executive function informed latent profile analyses that yielded four interpretable profiles. These profiles included Cognitive superagers, a Memory strength profile, an Executive Function/Attention strength profile, and a Low cognitive performance profile. Latent transition analysis with measurement invariance showed that the extreme profiles were most stable. Downward transitions were more common than upward transitions, and improvement from the lowest cognitive performance profile was uncommon. Three-step models evaluated profile membership and maintenance by health-related covariates. Older age was strongly associated with lower cognitive profile membership and cognitive decline, whereas higher education and greater physical activity were associated with cognitive superager membership and maintenance of cognitive functioning. Multimorbidity, depressive symptoms, and sleep disturbance were associated with lower profile assignment and increased risk of decline. Sensitivity analyses that addressed survivorship and attrition, including a pattern mixture specification and a stayers-only specification, elucidated the sensitivity of the profile structure on attrition, at baseline, but robustness of the direction of covariate associations. An exploratory analysis in the venous blood study subsample 2016 compared DNA methylation biomarkers across profiles. Cognitive superagers showed modestly high favorable epigenetic aging signals, and the pattern differed across the other cognitive profiles. Findings support a dynamic view of late-life cognition and inform targeted prevention strategies to ensure maintenance of cognitive reserve. | en |
| dc.description.abstractgeneral | Among older adults, the brain of everyone ages in a different ways. Some older adults, called "Cognitive Superagers," maintain memory and thinking abilities that resemble those of much younger people. This dissertation explored why that happens and what factors help some individuals stay mentally sharp well into their 80s. Using data from over 3,000 adults aged 75 and older who participated in the U.S. Health and Retirement Study in 2012, 2016, and 2020, this research identified different patterns of cognitive performance and tracked how people's profiles changed over time. Five tests covering memory, attention, reasoning, and language were analyzed using advanced statistical models to group individuals according to their performance on those tests. Four clear groups emerged: (1) Cognitive Superagers, who showed consistently high performance across all domains; (2) those with strong memory; (3) those with strong executive function and attention; and (4) overall low performers who struggled across domains. Over eight years, most older adults stayed in the same group, but when changes occurred, declines were more common than improvements. The study also examined lifestyle and health factors that predicted who stayed cognitively sharp. Predominantly, higher education attainment, greater physical activity, and fewer depressive symptoms supported maintenance of strong cognitive functioning. An exploratory sub-sample analysis explored biological aging and the Superagers showed more favorable biological aging profiles, meaning their bodies, like their minds, appeared younger than expected. These findings reveal that aging does not inevitably lead to only cognitive decline. Instead, brain health in later life is shaped by a mix of lifelong habits, mental engagement, and physical well-being. Understanding why some individuals maintain youthful cognition can guide interventions that promote resilience, healthy lifestyles, and cognitive longevity for all older adults. | en |
| dc.description.degree | Doctor of Philosophy | en |
| dc.format.medium | ETD | en |
| dc.identifier.other | vt_gsexam:45077 | en |
| dc.identifier.uri | https://hdl.handle.net/10919/139898 | en |
| dc.language.iso | en | en |
| dc.publisher | Virginia Tech | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject | Cognitive Superagers | en |
| dc.subject | Successful aging | en |
| dc.subject | Aging trajectories | en |
| dc.subject | Latent Transition Analysis | en |
| dc.title | Identifying Cognitive Profiles and Determinants of Cognitive Superaging Among Older Adults | en |
| dc.type | Dissertation | en |
| thesis.degree.discipline | Human Development | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | doctoral | en |
| thesis.degree.name | Doctor of Philosophy | en |
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