Longitudinal Stability and Cross-Sectional Correlates: Cognition, Stress, and Inflammation in Midlife.

Maintaining cognitive health during aging is critical, and sleep quality has emerged as a modifiable factor in cognitive decline. Yet, age-specific associations between sleep and long-term cognitive changes, independent of mental and neurological conditions, remain underexplored in nationally representative samples. Using data from the Midlife in the United States (MIDUS) study, sleep quality was assessed at MIDUS 2 with the Pittsburgh Sleep Quality Index (PSQI), and cognitive function was reassessed approximately 9.2 years later at MIDUS 3. Cognitive domains included episodic memory, executive functioning, and a composite score, standardized to MIDUS 2 means and standard deviations. Partial correlations examined associations between baseline sleep and cognitive change, controlling for age, sex, education level, psychiatric visits in the past 12 months, and neurological disorders in the past year from MIDUS 2. Analyses were stratified by age: older adults (≥65 years, n = 92) and young–middle-aged adults (< 65 years, n = 537). Among older adults, episodic memory decline was linked to poorer global sleep (r=-0.286, p = 0.005), longer sleep latency (r=-0.244, p = 0.018), and lower habitual sleep efficiency (r=-0.306, p = 0.003), with no associations for executive functioning. In contrast, among young–middle-aged adults, executive functioning decline was associated with poor subjective sleep quality (r=-0.116, p = 0.007) and shorter sleep duration (r=-0.113, p = 0.009). These findings highlight distinct age-specific vulnerabilities: episodic memory in older adults linked to structural sleep elements, and executive functioning in younger adults linked to subjective quality and duration. Tailored sleep interventions, emphasizing latency reduction and efficiency in older adults and duration/quality in younger adults, may help preserve long-term cognitive health.

Background Social stress and strain, especially discrimination and inequality might have an impact on memory and cognitive function. This is a major concern for older individuals, their families, communities and societies. We sought to assess changes in episodic memory (EM) and executive functioning (EF) among men and women in the 'Midlife in the United States' (MIDUS) cohort study, to delineate variations in EM and EF by gender, and to determine the impact of social stress/strain at three levels (family, work, society) on longitudinal changes in EM and EF in men and women. Methods We used data from the MIDUS study - a national probability sample of non-institutionalized, English speaking respondents aged 25-74 living in the 48 contiguous states of the United States. The initial wave in our study (1995) included 4963 non-institutionalized adults aged 32 to 84 (M = 55, SD = 12.4). The dependent variables are EM and EF, which were assessed with the Brief Test for Cognition. The independent variables were social stress and discrimination variables at the family/partner level, the work level and the society level, assessed with validated discrimination measures. To assess cognition changes we estimated adjusted linear regression models. Results Women report more perceived inequality for their family and more family strain than men across all age groups. After controlling for other explanatory variables, the main effect on cognition for all age groups was found for perceived inequality of one's family opportunities. Conclusions Reducing social stress and providing opportunities might be an important measure to support episodic memory and executive functioning in aging populations.

While personal growth has been found to be associated with multiple aspects of health in adulthood, its associations with cognitive functioning have not been fully understood. The present study aimed to assess both directions of such longitudinal associations. Using data from the second wave (T1) and third wave (T2) of the Midlife in the United States (MIDUS) study (N = 4,206; mean age = 56.0 [SD = 12.3]), a longitudinal measurement model containing latent variables of episodic memory and executive function was first constructed. Built on the measurement model, a structural equation model was analyzed to assess cross-lagged relationships between personal growth and the two areas of cognitive functioning, in which T1 personal growth predicted residualized changes in episodic memory and executive function, and T1 episodic memory and executive function predicted change in personal growth, controlling for covariates. The results indicated that T1 personal growth significantly predicted smaller decreases in episodic memory, whereas it did not predict change in executive function. T1 episodic memory, but not T1 executive function, significantly predicted smaller decreases in personal growth. The present findings were unique, particularly implying potential longitudinal reciprocity between personal growth and episodic memory. These findings and implications can inform future research aimed at exploring approaches to promoting personal growth and cognitive functioning among aging adults.

Background We sought to assess changes in episodic memory and executive functioning among men and women in the Midlife in the United States (MIDUS) cohort study; and to delineate variations in episodic memory and executive functioning by gender; and to determine the impact of discrimination on longitudinal changes in episodic memory and executive functioning. Methods We used data from the MIDUS study - a national probability sample of non-institutionalized, English speaking respondents aged 25-74 living in the 48 contiguous states of the United States. The initial wave in our study (1995) included 4963 non-institutionalized adults aged 32 to 84 (M = 55, SD = 12.4). Dependent variables are episodic memory and executive functioning, assessed with the Brief Test for Cognition. The independent variables were discrimination (lifetime and daily discrimination) variables. Furthermore, we investigated baseline cognition score, race/ethnicity (White, Hispanic, other), education (some college or more vs high school of less), whether or not living with partner, income (per 100% above Federal Poverty Level), unemployed (vs employed), retired (vs employed), physical health (self-reported), vigorous physical activity, depression (continuous scale), anxiety (continuous scale). To assess cognition changes we estimated adjusted linear regression models. Results Cross-sectional, work discrimination was associated with cognition in men and women. Longitudinally, adjusting for baseline cognition score, race/ethnicity, education, living situation, income, (un)employed, (not)retired, physical health, vigorous physical activity, depression, and anxiety, we found an association of family strain with cognition changes in high-income men, and an association of daily discrimination with cognition changes in men (Beta 0.01, P-value: 0.001). Conclusions Reducing discrimination might be an important measure to support cognitive function in ageing populations.

<p>Early life adversity is consequential for poor cognitive health in mid to late-life. Early life adversity is associated with higher allostatic load, a biological indicator of physiological dysregulation due to cumulative wear-and-tear from chronic stress. Higher allostatic load is also associated with poorer cognitive function across the lifespan. To date, a paucity of research has examined allostatic load as a mechanism through which early life adversity impacts cognition in adulthood. Using cross-sectional data from the Midlife in the United States (MIDUS) Study, the objective of the current study was to investigate the mediating role of allostatic load in the relationship between early life adversity and cognitive performance (global cognition, episodic memory, executive function) among middle-aged and older adults without cognitive impairment (n = 1541, Mage=53 ± 12, 53% female). Early life adversity was measured retrospectively using the Childhood Trauma Questionnaire. Allostatic load was composed of 20 biomarker proxies of neuroendocrine, metabolic, inflammatory, and cardiovascular systems, stratified by sex. Cognitive performance was evaluated using a battery of standardized neuropsychological tests. Controlling for age, education, and race, allostatic load significantly mediated the relationship between early life adversity and global cognition (ß=−0.01, 95%CI [−0.01,−0.001]), and early life adversity and executive function (ß=−0.01, 95%CI [−0.01,−0.001]), but not episodic memory. Findings did not change after controlling for lifestyle behaviours and current depression. Consistent with the biopsychosocial lifespan model of cognitive aging, findings suggest that early life adversity may become biologically embedded over time to negatively impact cognitive function in later adulthood in a domain-specific manner.</p>

<p>Early life adversity is consequential for poor cognitive health in mid to late-life. Early life adversity is associated with higher allostatic load, a biological indicator of physiological dysregulation due to cumulative wear-and-tear from chronic stress. Higher allostatic load is also associated with poorer cognitive function across the lifespan. To date, a paucity of research has examined allostatic load as a mechanism through which early life adversity impacts cognition in adulthood. Using cross-sectional data from the Midlife in the United States (MIDUS) Study, the objective of the current study was to investigate the mediating role of allostatic load in the relationship between early life adversity and cognitive performance (global cognition, episodic memory, executive function) among middle-aged and older adults without cognitive impairment (n = 1541, Mage=53 ± 12, 53% female). Early life adversity was measured retrospectively using the Childhood Trauma Questionnaire. Allostatic load was composed of 20 biomarker proxies of neuroendocrine, metabolic, inflammatory, and cardiovascular systems, stratified by sex. Cognitive performance was evaluated using a battery of standardized neuropsychological tests. Controlling for age, education, and race, allostatic load significantly mediated the relationship between early life adversity and global cognition (ß=−0.01, 95%CI [−0.01,−0.001]), and early life adversity and executive function (ß=−0.01, 95%CI [−0.01,−0.001]), but not episodic memory. Findings did not change after controlling for lifestyle behaviours and current depression. Consistent with the biopsychosocial lifespan model of cognitive aging, findings suggest that early life adversity may become biologically embedded over time to negatively impact cognitive function in later adulthood in a domain-specific manner.</p>

The mediating role of allostatic load in the relationship between early life adversity and cognitive function across the adult lifespan

Biological correlates of adult cognition: Midlife in the United States (MIDUS)

Early life adversity (ELA) is consequential for poor cognitive health in mid to late life. ELA is associated with higher allostatic load (AL), a biological indicator of physiological dysregulation due to cumulative wear-and-tear from chronic stress. Higher AL is also associated with poorer cognitive function across the lifespan. To date, however, a paucity of research has investigated AL as a mechanism through which ELA impacts cognition. Using cross-sectional data from the Midlife in the United States (MIDUS) Study, the objective of this study was to investigate the mediating role of AL in the relationship between ELA and cognitive performance (global cognition, episodic memory, executive function) among middle-aged and older adults without cognitive impairment (n=1541, mean age=53±12, 53% female). ELA, including physical, emotional, and sexual experiences, was measured retrospectively using the Childhood Trauma Questionnaire. AL was composed of 20 biomarker proxies of neuroendocrine, metabolic, inflammatory, and cardiovascular systems, stratified by sex. Cognitive performance was evaluated using a battery of neuropsychological tests from the Brief Test of Adult Cognition by Telephone. Controlling for age, education, and ethnicity, AL significantly mediated the relationship between ELA and global cognition (ß=-0.01,95%CI[-0.02,-0.003]) and executive function (ß=-0.01,95%CI[-0.02,-0.003]) such that higher ELA was associated with higher AL, and higher AL was associated with poorer global cognition and executive function. No such effects were found for episodic memory. Consistent with the biopsychosocial lifespan model of cognitive aging, findings suggest that ELA may become biologically embedded over time to negatively impact cognitive function in later adulthood in a domain-specific manner.

A substantial body of research has documented age-related declines in cognitive abilities among adults over 60, yet there is much less known about changes in cognitive abilities during midlife. The goal was to examine longitudinal changes in multiple cognitive domains from early midlife through old age in a large national sample, the Midlife in the United States (MIDUS) study. The Brief Test of Adult Cognition by Telephone (BTACT) was administered on two occasions (MIDUS 2, MIDUS 3), an average of 9 years apart. At MIDUS 3, those with the cognitive assessment (N=2518) ranged in age from 42 to 92 years (M=64.30; SD=11.20) and had a mean education of 14.68 years (SD=2.63). The BTACT includes assessment of key aging-sensitive cognitive domains: immediate and delayed free recall, number series, category fluency, backward digit span, processing speed, and reaction time for attention switching and inhibitory control, which comprise two factors: episodic memory and executive functioning. As predicted, all cognitive subtests and factors showed very small but significant declines over 9 years, with differences in the timing and extent of change. Processing speed showed the earliest and steepest decrements. Those with higher educational attainment scored better on all tests except reaction time. Men had better executive functioning and women performed better on episodic memory. Examining cognitive changes in midlife provides opportunities for early detection of cognitive impairments and possibilities for preventative interventions. (JINS, 2018, 24, 805-820).

Movement-based mind-body practices and cognitive function in middle-aged and older adults: Findings from the Midlife in the United States (MIDUS) study

The current study examined whether informal caregivers performed worse, better, or similar to non-caregivers on cognitive tests of executive functioning and episodic memory over 10years. Methods: Data were from waves 2 (2003-04) and 3 (2013-14) of the Midlife in the United States (MIDUS) study (N = 2086). Multiple linear regression models examined whether caregiving at both waves 2 and 3 predicted better cognitive functioning at wave 3, than caregiving at only one time point or no caregiving (reference) while controlling for baseline covariates (i.e., sociodemographic, health, and functional status). After controlling for covariates, caregiving at both waves was independently associated with better performance in episodic memory (b = .24, SE = .10, p = .013) but not executive function (b = -.06, SE = .05, p = .246). Discussion:The findings partially supported both healthy caregiver and stress process models, indicating caregiving may be associated with better episodic memory but not executive functioning over time among the middle-aged and older adults.

Cognitive function is an important component of healthy ageing. However, it is unclear whether relaxation/meditation practices provide cognitive benefits, particularly in midlife and early late life. Meditative practices are associated with higher self-esteem, and self-esteem serves as a general protective factor for many health outcomes. The current study examines associations between meditation practice, self-esteem, and change over 10 years in midlife cognitive performance. Data were from waves 2 (2003-2004) and 3 (2013-2014) of the Midlife in the United States (MIDUS) study. We used structural equation modelling to examine whether persistent meditation practice at both waves or episodic practice at one wave is associated with better cognitive function over 10 years, compared to no meditation practice, while controlling for prior cognitive function and covariates (baseline socio-demographics, health, and functional status). Additionally, we assessed if self-esteem mediates the above associations. We included 2168 individuals (Mage = 65 ± 11). After controlling for covariates, the findings revealed that persistent meditation practice in both waves was associated with significantly less decline in episodic memory; however, no such effects were found for executive function. Further, although participants' higher self-esteem was significantly associated with less decline in executive function and episodic memory, it did not mediate the associations between meditation practice and cognitive functions. While both persistent meditation practice and self-esteem have associations with cognitive outcomes for middle-aged and older adults in MIDUS, self-esteem as a mediator was not supported. Thus, future investigations should examine mechanisms that underlie these protective factors on cognitive performances across adulthood.

While personal growth has been found to be associated with multiple aspects of health in adulthood, its associations with cognitive functioning have not been fully understood. The present study aimed to assess both directions of such longitudinal associations. Using data from the second wave (Time 1 [T1]) and third wave (Time 2 [T2]) of the Midlife in the United States (MIDUS) study (N = 4,206; mean age = 56.0 [standard deviation (SD) = 12.3]), a longitudinal measurement model containing latent variables of episodic memory and executive function was first constructed. Built on the measurement model, a cross-lagged panel model was analyzed to assess relationships between personal growth and the two areas of cognitive functioning, in which T1 personal growth predicted residualized changes in episodic memory and executive function, and T1 episodic memory and executive function predicted change in personal growth, controlling for covariates. T1 personal growth significantly predicted smaller decreases in episodic memory, whereas it did not predict change in executive function. T1 episodic memory, but not T1 executive function, significantly predicted smaller decreases in personal growth. The present findings were unique, particularly implying potential longitudinal reciprocity between personal growth and episodic memory. These findings and implications can inform future research aimed at exploring approaches to promoting personal growth and cognitive functioning among aging adults.

Frequent Cognitive Activity Compensates for Education Differences in Episodic Memory