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Research Summary:

My research considers life span development and aging outcomes, particularly the coaction and interplay of genes and environments on cognitive aging and the risk of Alzheimer's disease and related dementias (ADRD). I engage in longitudinal research, often of twins and adoptees, to examine how and why individuals differ in early life contexts and behavioral health pathways across time and their effects on cognitive functioning. Cognitive resilience in the face of genetic and environmental risks is a current direction of interest. In addition to participating in the international Interplay of Genes and Environment Across Multiple Studies (IGEMS) consortia and the Vietnam Era Twin Study of Aging (VETSA), I am the contact PI of the Colorado Adoption/Twin Study of Lifespan behavioral development and cognitive aging (CATSLife).

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Highlighted Publications:

Using the CATSLife sample, we developed a frailty index with sibling similarity patterns suggesting that moderate genetic influences contribute to frailty differences in early adulthood. Moreover, frailty is associated with worse performance on the Digit Symbol Substitution Subtest, a processing speed task evidencing increasingly stronger associations at higher ages. Thus, even in adults approaching midlife, an understudied period within lifespan development, indicators of vulnerability to stress as indexed by frailty are associated with processing speed and warrant additional longitudinal investigation.

(The Journals of Gerontology: Series B, 2023)

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Using the longitudinal Swedish Adoption/Twin Sample of Aging (SATSA) study with multiple assessments of frailty and DNA methylation, longitudinal dynamic analyses of the temporal relationships revealed that increased epigenetic aging indexed by the Dunedin PACE methylation biomarker precedes changes in frailty. Findings suggest that an accelerated pace of aging may lead to increased physiological vulnerability to stress manifesting in higher frailty.

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(The Journals of Gerontology: Series A, 2023)

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Using data from the IGEMS consortium, we observed that for Semantic Fluency and Episodic Memory tasks, genetic influences contribute to cognitive function at shorter sleep durations (4 hours) to a greater degree than at longer sleep durations (10 hours), consistent with prior work in the field suggesting that short sleep may be associated with an upregulation of neuroinflammatory processes and ineffective beta-amyloid clearance.

(Sleep, 2022)

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The first report to include polygenic scores for Alzheimer's disease (AD) simultaneously in a biometrical twin model of AD risk in Swedish twins. APOE accounts for much of the measured polygenic contribution with substantial background genetic influences still to be understood.

(Brain Communications, 2022)