Complexity of Work and Incident Cognitive Impairment in Puerto Rican Older Adults

Trajectories of Occupational Cognitive Demands and Risk of Mild Cognitive Impairment and Dementia in Later Life: The HUNT4 70+ Study

BACKGROUND AND OBJECTIVES

The cognitive reserve hypothesis posits that cognitively stimulating work delays the onset of mild cognitive impairment (MCI) and dementia. However, the effect of occupational cognitive demands across midlife on the risk of these conditions is unclear.

METHODS

Using a cohort study design, we evaluated the association between registry-based trajectories of occupational cognitive demands from ages 30-65 years and clinically diagnosed MCI and dementia in participants in the HUNT4 70+ Study (2017-19). Group-based trajectory modeling identified trajectories of occupational cognitive demands, measured by the routine task intensity (RTI) index (lower RTI indicates more cognitively demanding occupation) from the Occupational Information Network. Multinomial regression was implemented to estimate the relative risk ratios (RRRs) of MCI and dementia, after adjusting for age, sex, education, income, baseline hypertension, obesity, diabetes, psychiatric impairment, hearing impairment, loneliness, smoking status, and physical inactivity assessed at HUNT1-2 in 1984-1986 and 1995-1997. To handle missing data, we used inverse probability weighting to account for nonparticipation in cognitive testing and multiple imputation.

RESULTS

Based on longitudinal RTI scores for 305 unique occupations, 4 RTI trajectory groups were identified (n = 7,003, 49.8% women, age range 69-104 years): low RTI (n = 1,431, 20.4%), intermediate-low RTI (n = 1,578, 22.5%), intermediate-high RTI (n = 2,601, 37.1%), and high RTI (n = 1,393, 19.9%). Participants in the high RTI group had a higher risk of MCI (RRR 1.74, 95% CI 1.41-2.14) and dementia (RRR 1.37, 95% CI 1.01-1.86), after adjusting for age, sex, and education compared with participants in the low RTI group. In a sensitivity analysis, controlling for income and baseline health-related factors, the point estimates were not appreciably changed (RRR 1.66, 95% CI 1.35-2.06 for MCI, and RRR 1.31, 95% CI 0.96-1.78 for dementia).

DISCUSSION

People with a history of cognitively stimulating occupations during their 30s, 40s, 50s, and 60s had a lower risk of MCI and dementia older than 70 years, highlighting the importance of occupational cognitive stimulation during midlife for maintaining cognitive function in old age. Further research is required to pinpoint the specific occupational cognitive demands that are most advantageous for maintaining later-life cognitive function.

Work and self-rated memory among native Hawaiian and other Pacific Islander older adults

OBJECTIVES

Engagement in work has an important association with cognitive health in later life, yet little is known about this association among Native Hawaiian and other Pacific Islander (NHPI) older adults. This study assesses the associations between various work characteristics and memory problems among this population.

DESIGN

Using data from the 2014 Native Hawaiian and Pacific Islander National Health Interview Survey (NHPI NHIS), the research question was explored among those who were aged 50+.

RESULTS

Engagement in work, certain occupation types (e.g., clerical or professional occupations compared to blue-collar jobs), and the current/most recent job that is also the longest job held were associated with lower odds of having memory problems.

CONCLUSION

The study's results suggest that work characteristics and opportunities to engage in work are important considerations in preventing memory problems in later life. As the NHPI population experiences cognitive health disparities earlier than other groups, timely interventions that focus on work engagement and a culturally relevant environment require further investigation.

Lifetime occupational skill and later-life cognitive function among older adults in the United States, Mexico, India, and South Africa

INTRODUCTION

We conducted a cross-national comparison of the association between main lifetime occupational skills and later-life cognitive function across four economically and socially distinct countries.

METHODS

Data were from population-based studies of aging and their Harmonized Cognitive Assessment Protocols (HCAPs) in the US, South Africa, India, and Mexico (N = 10,037; Age range: 50 to 105 years; 2016 to 2020). Main lifetime occupational skill was classified according to the International Standard Classification of Occupations. Weighted, adjusted regression models estimated pooled and country-specific associations between main lifetime occupational skill and later-life general cognitive function in men and women.

RESULTS

We observed positive gradients between occupational skill and later-life cognitive function for men and women in the US and Mexico, a positive gradient for women but not men in India, and no association for men or women in South Africa.

DISCUSSION

Main lifetime occupations may be a source of later-life cognitive reserve, with cross-national heterogeneity in this association.

HIGHLIGHTS

No studies have examined cross-national differences in the association of occupational skill with cognition. We used data from Harmonized Cognitive Assessment Protocols in the US, Mexico, India, and South Africa. The association of occupational skill with cognitive function varies by country and gender.

Income-Related Inequalities in Physical and Cognitive Health Domains Over the Later Life Course: Longitudinal Evidence From the U.S. (1992-2016)

This study aims to investigate changes in the income-health gradient over the later life course. We test the age-as-leveler, the cumulative advantage/disadvantage, and the persistent inequality pattern for physical and cognitive health domains, and analyze whether these patterns are gendered. We used HRS data (1992-2016) and Poisson growth curve models to predict multimorbidity (33,860 participants) as an indicator of physical health and memory (25,291 participants) as an indicator of cognitive health. We disentangled the within-participant from the between-participant effects. For multimorbidity, the income-health gradient weakened as individuals aged; whereas for memory, the income-health gradient strengthened as individuals aged. The cumulative advantage/disadvantage of higher/lower income on memory may be more pronounced among women than men. Findings were confirmed by sensitivity analyses. Findings suggest that the support for the age-as-leveler or cumulative advantage/disadvantage pattern may depend on health domains and the effect strength may depend on gender.

Association of primary lifetime occupational cognitive complexity and cognitive decline in a diverse cohort: Results from the KHANDLE study

INTRODUCTION

Higher occupational complexity has been linked to favorable cognitive outcomes, but rarely examined in racially and ethnically diverse populations.

METHODS

In a diverse cohort (n = 1536), linear mixed-effects models estimated associations between main lifetime occupational complexity and domain-specific cognitive decline (z-standardized). Occupational complexity with data, people, and things were classified using the Dictionary of Occupational Titles.

RESULTS

For occupational complexity with data, highest tertile (vs. lowest) was associated with higher baseline executive function (β = 0.11; 95% confidence interval [CI] 0.00-0.22) and slower annual rate of decline (β = 0.03; 95% CI 0.01-0.06), and higher baseline semantic memory (β = 0.14; 95% CI 0.04-0.25). Highest tertile of occupational complexity with people was associated with higher baseline executive function (β = 0.29; 95% CI 0.18-0.40), verbal episodic memory (β = 0.12; 95% CI 0.00-0.24), and semantic memory (β = 0.23; 95% CI 0.12-0.34).

DISCUSSION

In a diverse cohort, higher occupational complexity is associated with better cognition. Findings should be verified in larger cohorts.

HIGHLIGHT

Few studies have examined associations of occupational complexity with cognition in diverse populations. Racial and ethnic minorities are disproportionately exposed to lower occupational complexity. Occupational complexity with data and people are associated with better cognition.

Association of mental demands in the workplace with cognitive function in older adults at increased risk for dementia

Objectives

Growing evidence suggests a protective effect of high mental demands at work on cognitive function in later life. However, evidence on corresponding associations in older adults at increased risk for dementia is currently lacking. This study investigates the association between mental demands at work and cognitive functioning in the population of the AgeWell.de-trial.

Methods

Cross-sectional investigation of the association between global cognitive functioning (Montreal Cognitive Assessment) and mental demands at work in older individuals at increased risk for dementia (Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE)score ≥ 9; n = 941, age: 60–77 years). Occupational information was matched to Occupational Information Network (O*NET)-descriptors. Associations between cognitive function and O*NET-indices executive, verbal and novelty were investigated using generalized linear models.

Results

Higher values of index verbal (b = .69, p = .002) were associated with better cognitive function when adjusting for covariates. No association was observed for indices executive (b = .37, p = .062) and novelty (b = .45, p = .119). Higher education, younger age, and employment were linked to better cognitive function, while preexisting medical conditions did not change the associations. Higher levels of depressive symptomatology were associated with worse cognitive function.

Conclusions

Higher levels of verbal demands at work were associated with better cognitive function for older adults with increased dementia risk. This suggests an advantage for older persons in jobs with high mental demands even after retirement and despite prevalent risk factors. Longitudinal studies are warranted to confirm these results and evaluate the potential of workplaces to prevent cognitive decline through increased mental demands.

Protective factors for subjective cognitive decline individuals: trajectories and changes in a longitudinal study with Italian elderly

BACKGROUND AND PURPOSE

Many different factors have been hypothesized to modulate cognition in an aging population according to their functioning at baseline.

METHODS

This retrospective study quantifies the relative contribution of age and sex as demographic factors, comorbidity, education and occupation (classified with the International Standard Classification of Occupation 2008) as cognitive reserve proxies in accounting for cognitive aging. All participants (3081) were evaluated at baseline with a complete neuropsychological test battery (T1) and those with unimpaired profiles were classified as subjective cognitive decline, those mildly impaired as mild neurocognitive decline and those severely impaired as major neurocognitive decline. From the first assessment 543 individuals were assessed a second time (T2), and 125 a third time (T3). Depending on whether they maintained or worsened their profile, based on their initial performance, participants were then classified as resistant or declining.

RESULTS

At baseline, all individuals showed education and occupation as the best predictors of performance, in addition to age. Furthermore, across assessments, the resistant had higher levels of education and occupation than the declining. In particular, the education and occupation predicted cognitive performance in all groups considered, from the subjective cognitive decline to the one with the most severely impaired participants.

CONCLUSIONS

This study highlights the role of working activity in protecting from cognitive decline across all fragile elderly groups and even more so the individuals who are at very high risk of decline.

The Association between Social Support and Cognitive Impairment among the Urban Elderly in Jinan, China

China is currently facing a severe challenge of population ageing. However, no study has specifically explored the association between social support and cognitive impairment in Chinese urban elderly aged 60 and older. We explored the prevalence of cognitive impairment and its relationship with social support among the urban elderly aged above 60 years in Jinan, China. A total of 522 urban elderly individuals were recruited using multi-stage cluster random sampling, of which 35.55% were males and 64.45% were females. The average age of all participants was 69.66 ± 8.91 years old. Social support was assessed using the Social Support Rating Scale. Cognitive status was assessed using the Mini-Mental State Examination. Data were collected through face-to-face interviews using structured questionnaires. Descriptive analysis, chi-square tests, and logistic regression analyses were conducted. After analysing the data from 512 participants, 154 (30.1%), 352 (68.8%), and 6 (1.2%) participants had high, moderate, and low levels of social support, respectively. In addition, 125 participants (24.4%) had a cognitive impairment, while the other 387 participants (75.6%) had a normal cognitive status. Binary logistic regression analyses showed that age, educational level, occupation or pre-retirement occupation, and social support were statistically associated with cognitive impairment. A significant association between social support and cognitive impairment was found among the urban elderly in Jinan, China, which provided useful information for the intervention of cognitive impairment. More attention should be paid to the social support of the urban elderly to effectively reduce the occurrence of cognitive impairment.

On the Biopsychosocial Costs of Alienated Labor

Data from the national, longitudinal Mid-Life in the US (MIDUS) study were used to examine work alienation and its relationship to biological health as well as psychological and social functioning. The alienation measure focuses on the autonomy and creativity the work provides. We hypothesized that alienated work would have negative associations with each of the three domains: in biology, higher 'allostatic load' (biological dysregulation); in psychology, poorer cognitive performance; and socially, negative impacts on family life. The outcomes are generally as predicted, though there are notable differences for men and women.

Multifaceted Demands of Work and Their Associations with Cognitive Functioning: Findings From the Health and Retirement Study

OBJECTIVES

The present study examines the associations among mental, social, and physical demands of work with cognitive functioning among older adults in the United States.

METHODS

Data from 3,176 respondents in the Health and Retirement Study were analyzed using growth curve modeling (2004-2014). The study investigated differences by gender, race, ethnicity, and education.

RESULTS

Higher mental and social demands of work were associated with higher levels of initial cognitive functioning, but not significantly associated with slower cognitive decline over time. Physical demands of work were negatively associated with initial cognitive functioning and also marginally associated with a slower rate of decline in cognitive functioning going into older adulthood. In stratified analyses, results varied by sociodemographic characteristics.

DISCUSSION

The results partially support the environmental complexity hypothesis and the productive aging framework in that higher mental and social demands and lower physical demands relate to better cognitive functioning at baseline, with the differences appearing stable throughout older adulthood. The stratified results shed light on addressing disparities in cognitive aging and work environments.

Job Strain and Late-Life Cognition: Findings From the Puerto Rican Elderly Health Conditions Study

Objectives: We examined associations between job strain and cognitive aging in a sample of older Puerto Ricans. Methods: Members of the Puerto Rican Elderly: Health Conditions study, aged 60-100 years at baseline, participated. Job strain indicators were quantified from O*NET (n = 1632) and a matrix of Job Content Questionnaire scores (JCQ; n = 1467). Global cognition was assessed twice across 4 years. Results: Controlling for age, sex, depressive symptoms, financial problems, hypertension, diabetes, childhood economic hardship, low job control and high job strain were consistently associated with greater cognitive decline. Adding education attenuated these associations. High education strengthened the JCQ job control-cognitive change link. Discussion: Low job control and high job strain may accelerate cognitive aging in this population. However, it may be more difficult to disentangle the intersecting roles of education and job strain in cognitive aging among older Puerto Ricans relative to older adults from contiguous United States or Europe.

Work Hours and Cognitive Function: The Multi-Ethnic Study of Atherosclerosis

Background

Cognitive impairment is a public health burden. Our objective was to investigate associations between work hours and cognitive function.

Methods

Multi-Ethnic Study of Atherosclerosis (MESA) participants (n = 2,497; 50.7% men; age range 44–84 years) reported hours per week worked in all jobs in Exams 1 (2000–2002), 2 (2002–2004), 3 (2004–2005), and 5 (2010–2011). Cognitive function was assessed (Exam 5) using the Cognitive Abilities Screening Instrument (version 2), a measure of global cognitive functioning; the Digit Symbol Coding, a measure of processing speed; and the Digit Span test, a measure of attention and working memory. We used a prospective approach and linear regression to assess associations for every 10 hours of work.

Results

Among all participants, associations of hours worked with cognitive function of any type were not statistically significant. In occupation-stratified analyses (interaction p = 0.051), longer work hours were associated with poorer global cognitive function among Sales/Office and blue-collar workers, after adjustment for age, sex, physical activity, body mass index, race/ethnicity, educational level, annual income, history of heart attack, diabetes, apolipoprotein E-epsilon 4 allele (ApoE4) status, birth-place, number of years in the United States, language spoken at MESA Exam 1, and work hours at Exam 5 (β = –0.55, 95% CI = –0.99, –0.09) and (β = –0.80, –1.51, –0.09), respectively. In occupation-stratified analyses (interaction p = 0.040), we also observed an inverse association with processing speed among blue-collar workers (adjusted β = –0.80, –1.52, –0.07). Sex, race/ethnicity, and ApoE4 did not significantly modify associations between work hours and cognitive function.

Conclusion

Weak inverse associations were observed between work hours and cognitive function among Sales/Office and blue-collar workers.