Munoz, E., Filshtein, T., Bettcher, B. M., McLaren, D., Hedden, T., Tommet, D., Mungas, D., et al. Cognitive function and neuropathological outcomes: a forward-looking approach.
Journal of Neurology.
Publisher's VersionAbstractObjectiveTo evaluate the risk of Alzheimer’s disease-related neuropathology burden at autopsy given older adults’ current cognitive state.MethodParticipants included 1,303 individuals who enrolled in the Religious Orders Study (ROS) and 1,789 who enrolled in the Rush Memory and Aging Project (MAP). Cognitive status was evaluated via standardized assessments of global cognition and episodic memory. At the time of analyses, about 50% of participants were deceased with the remaining numbers right censored. Using multi-state Cox proportional hazard models, we compared the cognitive status of all subjects alive at a given age and estimated future risk of dying with different AD-related neuropathologies. Endpoints considered were Braak Stages (0–2, 3–4, 5–6), CERAD (0, 1, 2, 3), and TDP-43 (0, 1, 2, 3) level.ResultsFor all three pathological groupings (Braak, CERAD, TDP-43), we found that a cognitive test score one standard deviation below average put individuals at up to three times the risk for being diagnosed with late stage AD at autopsy according to pathological designations. The effect remained significant after adjusting for sex, APOE-e4 status, smoking status, education level, and vascular health scores.ConclusionApplying multi-state modeling techniques, we were able to identify those at risk of exhibiting specific levels of neuropathology based on current cognitive test performance. This approach presents new and approachable possibilities in clinical settings for diagnosis and treatment development programs.
Phibbs, S., Stawski, R. S., MacDonald, S. W. S., Munoz, E., Smyth, J. M., & Sliwinski, M. J. The influence of social support and perceived stress on response time inconsistency. Aging & Mental Health ,
23 (2), 214–221.
Publisher's VersionAbstract
Objectives: Lack of social support and high levels of stress represent potentially modifiable risk factors for cognitive aging. In this study we examined the relationships between these two risk factors and response time inconsistency (RTI), or trial-to-trial variability in choice response time tasks. RTI is an early indicator of declining cognitive health, and examining the influence of modifiable psychosocial risk factors on RTI is important for understanding and promoting cognitive health during adulthood and old age.
Methods: Using data from a community sample study (n = 317; Mage = 49, range = 19-83), we examined the effects of social support, including size of network and satisfaction with support, global perceived stress, and their interactions on RTI.
Results: Neither size of network nor satisfaction with support was associated with RTI independent of perceived stress. Stress was positively associated with increased RTI on all tasks, independent of social support. Perceived stress did not interact with either dimension of social support to predict RTI, and perceived stress effects were invariant across age and sex.
Conclusion: Perceived stress, but not social support, may be a unique and modifiable risk factor for normal and pathological cognitive aging. Discussion focuses on the importance of perceived stress and its impact on RTI in supporting cognitive health in adulthood and old age.
Jylhävä, J., Hjelmborg, J., Soerensen, M., Munoz, E., Tan, Q., Kuja-Halkola, R., Mengel-From, J., et al. Longitudinal changes in the genetic and environmental influences on the epigenetic clocks across old age: Evidence from two twin cohorts.
EBioMedicine ,
40, 710–716.
Publisher's VersionAbstractBackground Measures based on DNA methylation, epigenetic clocks, have recently gained attraction as predictors of mortality and age-related pathologies. However, the origins of variation in these measures are not well understood. Methods In a pooled sample of 104 Swedish and Danish twin pairs, we estimated, at the mean age of 70 (baseline) and 79 years (follow-up), the genetic and environmental influences on the Horvath and Levine clocks. Findings A model incorporating additive genetic (A) and person-specific environmental (E) influences best explained the variation in both clocks. Heritability was estimated at 55% at baseline and at 51% at follow-up for the Horvath clock and 34% at baseline and 41% at follow-up for the Levine clock. For the Horvath clock, new sources of A influences emerged at follow-up, whereas for the Levine clock, the same A influences accounted for the genetic variance at both measurement occasions. The cross-time phenotypic correlations, 0·52 for the Horvath clock and 0·36 for the Levine clock, were mediated primarily by genetic factors, whereas the person-specific environmental factors were completely different at the two measurement occasions. Interpretation For both clocks, new sources of person-specific environmental influences emerge with age. The epigenetic clocks might thus be responsive to new environmental stimuli even at old age. Fund NIH (R01;AG04563;AG10175;AG028555) the MacArthur Foundation Research Network on Successful Aging, FAS/FORTE (97:0147:1B;2009-0795), Swedish Research Council (825-2007-7460;825-2009-6141;521-2013-8689;2015-03255;2015-06796;2018-02077), FORTE (2013-2292), the Strategic Research Program in Epidemiology at KI, VELUX FOUNDATION, NIA (P01-AG08761), the EU (FP7/2007-2011;259679) and The Danish National Program for Research Infrastructure 2007 (9-063256).