Secular changes in cognitive predictors of dementia and mortality in 70-year-olds

Changes in prevalence and incidence of dementia and risk factors for dementia: an analysis from cohort studies

BACKGROUND

Some cohort studies have reported a decline in dementia prevalence and incidence over time, although these findings have not been consistent across studies. We reviewed evidence on changes in dementia prevalence and incidence over time using published population-based cohort studies that had used consistent methods with each wave and aimed to quantify associated changes in risk factors over time using population attributable fractions (PAFs).

METHODS

We searched for systematic reviews of cohort studies examining changes in dementia prevalence or incidence over time. We searched PubMed for publications from database inception up to Jan 12, 2023, using the search terms "systematic review" AND "dementia" AND ("prevalence" OR "incidence"), with no language restrictions. We repeated this search on March 28, 2024. From eligible systematic reviews, we searched the references and selected peer-reviewed publications about cohort studies where dementia prevalence or incidence was measured in the same geographical location, at a minimum of two timepoints, and that reported age-standardised prevalence or incidence of dementia. Additionally, data had to be from population-based samples, in which participants' cognitive status was assessed and where validated criteria were used to diagnose dementia. We extracted summary-level data from each paper about dementia risk factors, contacting authors when such data were not available in the published paper, and calculated PAFs for each risk factor at all available timepoints. Where possible, we linked changes in dementia prevalence or incidence with changes in the prevalence of risk factors.

FINDINGS

We identified 1925 records in our initial search, of which five eligible systematic reviews were identified. Within these systematic reviews, we identified 71 potentially eligible primary papers, of which 27 were included in our analysis. 13 (48%) of 27 primary papers reported change in prevalence of dementia, ten (37%) reported change in incidence of dementia, and four (15%) reported change in both incidence and prevalence of dementia. Studies reporting change in dementia incidence over time in Europe (n=5) and the USA (n=5) consistently reported a declining incidence in dementia. One study from Japan reported an increase in dementia prevalence and incidence and a stable incidence was reported in one study from Nigeria. Overall, across studies, the PAFs for less education or smoking, or both, generally declined over time, whereas PAFs for obesity, hypertension, and diabetes generally increased. The decrease in PAFs for less education and smoking was associated with a decline in the incidence of dementia in the Framingham study (Framingham, MA, USA, 1997-2013), the only study with sufficient data to allow analysis.

INTERPRETATION

Our findings suggest that lifestyle interventions such as compulsory education and reducing rates of smoking through country-level policy changes could be associated with an observed reduction, and therefore future reduction, in the incidence of dementia. More studies are needed in low-income and middle-income countries, where the burden of dementia is highest, and continues to increase.

FUNDING

National Institute for Health and Care Research Three Schools' Dementia Research Programme.

Attrition in the Gothenburg H70 birth cohort studies, an 18-year follow-up of the 1930 cohort

Background

Longitudinal studies are essential to understand the ageing process, and risk factors and consequences for disorders, but attrition may cause selection bias and impact generalizability. We describe the 1930 cohort of the Gothenburg H70 Birth Cohort Studies, followed from age 70 to 88, and compare baseline characteristics for those who continue participation with those who die, refuse, and drop out for any reason during follow-up.

Methods

A population-based sample born 1930 was examined with comprehensive assessments at age 70 (N = 524). The sample was followed up and extended to increase sample size at age 75 (N = 767). Subsequent follow-ups were conducted at ages 79, 85, and 88. Logistic regression was used to analyze baseline characteristics in relation to participation status at follow-up.

Results

Refusal to participate in subsequent examinations was related to lower educational level, higher blood pressure, and lower scores on cognitive tests. Both attrition due to death and total attrition were associated with male sex, lower educational level, smoking, ADL dependency, several diseases, poorer lung function, slower gait speed, lower scores on cognitive tests, depressive symptoms, and a larger number of medications. Attrition due to death was also associated with not having a partner.

Conclusions

It is important to consider different types of attrition when interpreting results from longitudinal studies, as representativeness and results may be differently affected by different types of attrition. Besides reducing barriers to participation, methods such as imputation and weighted analyses can be used to handle selection bias.

Better cognitive function in younger generations - Insights from two cohort studies of middle-aged to older adults in Wisconsin

BACKGROUND

Understanding generational trends in dementia and cognitive decline is essential to quantify future healthcare needs and may help identify interventions and preventions. We aimed to determine whether individuals from more recent generations showed better neurocognitive function.

METHODS

This cross-sectional study combined data from 4439 participants (mean age 64 years (SD = 13); 57% were women) from the Epidemiology of Hearing Loss Study and Beaver Dam Offspring Study. We assessed participants' birth cohort (1901-1924, Greatest Generation; 1925-1945, Silent Generation; 1946-1964, Baby Boom Generation; 1965-1984, Generation X) and neurocognition (Trail-Making Tests A and B, Digit Symbol Substitution Test, Auditory Verbal Learning Test, Verbal Fluency Test). Multivariable linear regression models were utilized.

RESULTS

Adjusted for age, sex, education, and known risk factors for cognitive decline, more recent generations showed better processing speed, executive function, attention, and verbal fluency than the Greatest Generation. Largest benefits were found in the Baby Boom Generation. Compared with the Greatest Generation, individuals from the Baby Boom Generation performed better on Trail-Making Tests A (-0.21 ln(time in s); 95% confidence interval (CI) -0.29, -0.13) and B (-0.31 ln(time in s); 95% CI -0.40, -0.22), Digit Symbol Substitution Test (6.07 numbers correct; 95% CI 3.61, 8.52) and Verbal Fluency Test (8.75 numbers correct; 95% CI 5.07, 12.42 in women; 5.28 numbers correct; 95% CI 0.79, 9.78 in men), with effect sizes similar to effects of 11-15 years of less aging.

CONCLUSIONS

This indicates that some benefits of younger generations might be related to yet unknown and potentially modifiable environmental, health-related or lifestyle factors and motivates research of such underlying factors to promote healthy cognitive aging.

Secular Trends in Dementia Free Cognitive Function in Older Adults: A Systematic Review

BACKGROUND

Although numerous studies have reported a decrease in dementia risk in the last two decades, it is unclear whether dementia-free cognitive function is also changing across generations.

OBJECTIVE

The objective was to systematically evaluate the published data on generational differences in cognitive function in the older population.

METHODS

Searches were performed on PubMed, Embase, and PsychInfo for articles published in English before 20 June 2021. Included studies were from population-based samples that reported generational differences in cognition in individuals without dementia, aged ≥60 years.

RESULTS

28,101 studies were identified and 15 selected covering the period from 1971 to 2015: including studies from China, Europe, and the USA. The results show generally consistent findings of improvements or stability in dementia free cognitive function in later versus earlier born generations, but not for all cognitive domains. Prevalence of mild cognitive impairment and cognitive impairment no dementia has remained stable in the USA, UK, and China over the last two decades.

RESULTS

Prevalence of vascular related mild cognitive impairment has increased in China. Improvements in cognition may only partially be explained by increased educational attainment across generations.

CONCLUSION

This review provides evidence for generational effects in dementia-free cognitive function, predominately stability or improvements in performance, in later compared to earlier born individuals across different world regions. There is an urgent need to determine the factors driving such changes and whether they are being experienced in all world regions, particularly low- and middle-income countries where the burden of cognitive impairment is greatest and rising.

Secular trends in prevalent mild cognitive impairment: Data from the Swedish population-based study Good Aging in Skåne

Background

Research suggests that incident dementia is decreasing, yet research on secular trends of prodromal dementia such as mild cognitive impairment (MCI) is lacking.

Methods

To determine change of MCI prevalence over time and potential explanatory factors, four baseline samples (years 2001-2020) of Swedish participants (n = 3910) aged 60 and 81 at examination were compared.

Results

An overall drop of 9 to 10 percentage points in MCI prevalence between 2001 and 2020 was observed, with lower odds ratios (OR) for MCI in the latest birth cohorts compared to earliest (e.g., ORs for 60-year-olds in latest born = 0.53; 95% confidence interval [CI] 0.37-0.76). Adjustments for sociodemographic (e.g., education), lifestyle, vascular and metabolic health and depression could not fully explain the observed MCI decline (e.g., 60-year-olds, OR = 0.59; 95% CI 0.40-0.88).

Discussion

Studies like this are imperative as even a slight postponement in the onset of dementia could have a substantial impact on future public health burden.

Trends in Cognitive Function Among Chinese Elderly From 1998 to 2018: An Age-Period-Cohort Analysis

Objectives: To investigate the effects of age, period, and cohort (APC) on trends in cognitive function among the Chinese elderly, and to explore how gender gaps in cognitive function change with age, period, and cohort. Methods: This study used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 1998 to 2018, and included 90,432 participants aged above 65 years old. The measurement of cognitive function was the score of the Mini-Mental State Examination (MMSE). Cross-classified random-effect models were used to investigate age, period, and cohort trends in cognitive function. Results: Mini-Mental State Examination scores decreased with age at an increasing rate. While the cohort effect was nearly stable, the period effect demonstrated a downward trend from 1998 to 2002 followed by a nearly flat line. Females were associated with lower MMSE scores than males. When age increased, the gender gaps in MMSE scores further increased. The period-based gender gaps in MMSE scores diverged throughout the 20 years, while the cohort-based gender disparities in MMSE scores converged with successive cohorts. Conclusions: Age, period, and cohort had different and independent effects on cognitive function among the Chinese elderly. The effect of age was stronger than that of period and cohort. Gender disparities in cognitive function increased with age and period, and decreased with successive cohorts.

Birth Cohorts and Cognitive Reserve Influence Cognitive Performances in Older Adults

BACKGROUND

Evidence suggests birth cohort differences in cognitive performance of older adults. Proxies of cognitive reserve (CR), such as educational attainment and occupational complexity, could also partly account for these differences as they are influenced by the sociocultural environment of the birth cohorts.

OBJECTIVE

To predict cognitive performance using birth cohorts and CR and examine the moderating influence of CR on cognitive performance and structural brain health association.

METHODS

Using ADNI data (n = 1628), four birth cohorts were defined (1915-1928; 1929-1938; 1939-1945; 1946-1964). CR proxies were education, occupational complexity, and verbal IQ. We predicted baseline cognitive performances (verbal episodic memory; language and semantic memory; attention capacities; executive functions) using multiple linear regressions with CR, birth cohorts, age, structural brain health (total brain volume; total white matter hyperintensities volume) and vascular risk factors burden as predictors. Sex and CR interactions were also explored.

RESULTS

Recent birth cohorts, higher CR, and healthier brain structures predicted better performance in verbal episodic memory, language and semantic memory, and attention capacities, with large effect sizes. Better performance in executive functions was predicted by a higher CR and a larger total brain volume, with a small effect size. With equal score of CR, women outperformed men in verbal episodic memory and language and semantic memory in all cohorts. Higher level of CR predicted better performance in verbal episodic memory, only when total brain volume was lower.

CONCLUSION

Cohort differences in cognitive performance favor more recent birth cohorts and suggests that this association may be partly explained by proxies of CR.

Factors Associated with Lower Cognitive Performance Scores Among Older Japanese Men in Hawaii and Japan

BACKGROUND

Few studies have compared factors related to cognitive function among people with similar genetic backgrounds but different lifestyles.

OBJECTIVE

We aimed to identify factors related to lower cognitive scores among older Japanese men in two genetically similar cohorts exposed to different lifestyle factors.

METHODS

This cross-sectional study of community-dwelling Japanese men aged 71-81 years included 2,628 men enrolled in the Kuakini Honolulu-Asia Aging Study based in Hawaii and 349 men in the Shiga Epidemiological Study of Subclinical Atherosclerosis based in Japan. We compared participant performance through Cognitive Abilities Screening Instrument (CASI) assessment in Hawaii (1991-1993) and Japan (2009-2014). Factors related to low cognitive scores (history of cardiovascular disease, cardiometabolic factors, and lifestyle factors) were identified with questionnaires and measurements. Multivariable logistic regression analysis was used to calculate the adjusted odds ratios (ORs) of a low (< 82) CASI score based on different factors.

RESULTS

CASI scores were lower in Hawaii than in Japan [21.2%(n = 556) versus 12.3%(n = 43), p < 0.001], though this was not significant when adjusted for age and educational attainment (Hawaii 20.3%versus Japan 17.9%, p = 0.328). History of stroke (OR = 1.65, 95%confidence interval = 1.19-2.29) was positively associated with low cognitive scores in Hawaii. Body mass index ≥25 kg/m2 tended to be associated with low cognitive scores in Japan; there was a significant interaction between the cohorts.

CONCLUSION

Cognitive scores differences between cohorts were mostly explained by differences in educational attainment. Conversely, cardiovascular diseases and cardiometabolic factors differentially impacted cognitive scores among genetically similar older men exposed to different lifestyle factors.

Passive and active suicidal ideation in Swedish 85-year-olds: Time trends 1986-2015

BACKGROUND

Older adults have high suicide rates. We investigated potential time trends in the prevalence of passive and active suicidal ideation in 85-year-olds. Further, we examined factors associated with such ideation in this age group.

METHODS

Population-based samples of 85-year-olds were interviewed in 1986 (N = 347), 2008 (N = 426) and 2015 (N = 320). Past-month passive/active suicidal ideation was evaluated with the Paykel questions.

RESULTS

Reporting any type of passive or active suicidal ideation was less common in 2008 (7.3%, p < 0.001) and 2015 (7.2%, p < 0.001) compared to 1986 (16.4%). The change was driven by decreases in passive ideation. Passive/active suicidal ideation was associated with higher MADRS score (OR: 1.2, 95% CI: 1.1-1.2, p < 0.001), institution residence (OR: 3.9, 95% CI: 1.7-8.9, p = 0.001) and feelings of loneliness (OR: 2.7, 95% CI: 1.4-5.2, p = 0.003). When stratified by sex, it was associated with institution residence (OR: 3.7, 95% CI: 1.4-9.9, p = 0.008) and feelings of loneliness (OR: 3.0, 95% CI: 1.4-6.3, p = 0.005) in women. In men, we observed a tenfold higher risk in those without partners (OR: 9.8, 95% CI: 2.9-33.5, p < 0.001).

LIMITATIONS

While differential three-year mortality was not observed in 1986, mortality was higher among non-participants in 2008 and 2015. This might have inflated cohort differences in passive/active suicidal ideation.

CONCLUSION

An initial decrease in the prevalence of passive/active suicidal ideation in 85-year-olds was observed but this positive trend did not persist. Results underline that preventive strategies targeting loneliness and focusing on institutional settings are needed, as are interventions for men without partners.

Time trends in the relation between blood pressure and dementia in 85-year-olds

OBJECTIVES

Blood pressure has decreased in the general population. We aimed to examine whether this is true also among the very old, and among persons with and without dementia. Further, we aimed to investigate how common undetected and untreated hypertension is in the very old, both among people with and without dementia.

METHOD

Blood pressure was measured in representative population samples of 85-year-olds living in Gothenburg, Sweden, examined 1986-1987 (n = 484) and 2008-2010 (n = 571). Dementia was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, edition 3 revised, by the same medical doctor at both examinations.

RESULTS

Both systolic and diastolic blood pressure were lower in 85-year-olds examined 2008-2010 than in those examined 1986-1987, both among those with and without dementia. Participants with dementia had lower systolic blood pressure than those without dementia in both cohorts, and blood pressure levels related to dementia severity. Despite this, hypertension (≥140/90 mmHg) was found in almost half (46.5%) of those with dementia in 2008-2010.

CONCLUSION

Our findings show that time-trends of lower blood pressure in western populations also applies to the very old, and that individuals with dementia continue to have lower blood pressure compared to the rest of the population. The latter finding suggests that the pathophysiological processes in dementia affect blood pressure regulating regions in the brain independent of time trends. Still, hypertension is common in dementia and needs to be detected and treated.

Sex Difference in the Relation Between Marital Status and Dementia Risk in Two Population-Based Cohorts

BACKGROUND

The modifying effect of sex on the relation between marital status and dementia has yet to be determined.

OBJECTIVE

To examine if sex modifies the association between marital status and incident dementia.

METHODS

Population-based samples from the Mayo Clinic Study of Aging (MCSA, N = 3,471) and the Gothenburg H70 Birth Cohort Study (H70-study, N = 913) were used. A multiplicative interaction term was used to analyze the modifying effect of sex on the relation between marital status (married versus not married) and incident dementia using Cox regression models. Further, risk of dementia by marital status was also evaluated in models separated by sex.

RESULTS

In the MCSA, there was an interaction between marital status and sex in relation to dementia (p = 0.015). In contrast, in the H70-study, no significant interaction was observed (p = 0.28). Nevertheless, in both studies, not married men had increased risk of dementia compared to married men in models adjusted for age, education, and number of children (H70-study: 1.99; 1.06-3.76, MCSA: 1.43; 1.08-1.89). Associations remained similar after additional adjustment for depression, BMI, hypertension, dyslipidemia, and diabetes mellitus (H70-study: 2.00; 1.05-3.82, MCSA: 1.32; 0.99-1.76). Further, no significant association was observed between marital status and dementia in women (H70-study: 1.24; 0.82-1.89, MCSA: 0.82; 0.64-1.04).

CONCLUSION

Sex had a modifying effect on the association between marital status and incident dementia. In analyses separated by sex, not married men had an increased risk of dementia compared to married men, while no significant association was observed between marital status and risk of dementia in women.

'I wanted to talk about it, but I couldn't', an H70 focus group study about experiencing depression in early late life

BACKGROUND

Knowledge about experiences of depression among younger-old adults from the general population is limited. The aim was to explore experiences of depression in early late life.

METHODS

Sixteen participants in the population-based Gothenburg H70 Birth Cohort Studies (12 women and 4 men) who had reported a history of depression between ages 60-70 took part in focus group discussions (n = 4). Data were analyzed using focus group methodology.

RESULTS

The analysis resulted in the overall theme 'I wanted to talk about it, but I couldn't'. The participants expressed unmet needs of communication about depression with family, friends, and healthcare staff. Participants wanted to know more about the causes and effects of depression, available treatment options and how to avoid recurrence. Lack of knowledge was a source of frustration; trust in health care providers was diminished. Being retired meant that opportunities for communication with co-workers were no longer available, and this made it harder to break negative thought and behavioral patterns. Being depressed meant losing one's normal self, and participants were grieving this. Thoughts of death and suicide were experienced in solitude; knowing that there was an escape could generate a feeling of comfort and control.

CONCLUSIONS

Younger-old adults have expressed a need to talk about their experiences of depression. They would like to know more about available treatments, potential side effects, and how to avoid recurrence. Care providers also need to be aware there is a need for an existential dialogue about death.

A New Look at Cohort Trend and Underlying Mechanisms in Cognitive Functioning

OBJECTIVES

The prevalence of dementia in the United States seems to have declined over the last few decades. We investigate trends and their underlying mechanisms in cognitive functioning (CF) across 7 decades of birth cohorts from the Greatest Generation to Baby Boomers.

METHODS

Data come from 30,191 participants of the 1996-2014 Health and Retirement Study. CF is measured as a summary score on a 35-point cognitive battery of items. We use generalized linear models to examine the trends in CF and explanatory variables across birth cohorts. Then, Karlson-Holm-Breen decomposition method is used to evaluate the contribution of each explanatory variable to the trend of CF.

RESULTS

CF has been improving from the Greatest Generation to Late Children of Depression and War Babies, but then significantly declines since the Early-Baby Boomers and continues into Mid-Baby Boomers. This pattern is observed universally across genders, race/ethnicities, education groups, occupations, income, and wealth quartiles. The worsening CF among Baby Boomers does not originate from childhood conditions, adult education, or occupation. It can be attributed to lower household wealth, lower likelihood of marriage, higher levels of loneliness, depression and psychiatric problems, and more cardiovascular risk factors (e.g., obesity, physical inactivity, hypertension, stroke, diabetes, and heart disease).

DISCUSSION

The worsening CF among Baby Boomers may potentially reverse past favorable trends in dementia as they reach older ages and cognitive impairment becomes more common if no effective interventions and policy responses are in place.

Predicting non-elective hospital readmission or death using a composite assessment of cognitive and physical frailty in elderly inpatients with cardiovascular disease

Background

We aimed to assess the utility of the combination of the mini-mental state examination (MMSE) + clock drawing test (CDT) and the Fried phenotype for predicting non-elective hospital readmission or death within 6 months in elderly inpatients with cardiovascular disease (CVD).

Methods

A single-center prospective cohort was conducted from September 2018 to February 2019. Inpatients ≥65 years old were recruited. Predictive validity was tested using a Cox proportional hazards regression model analysis, and the discriminative ability was evaluated by the receiver operating characteristic (ROC) curve.

Results

A total of 542 patients were included. Overall, 12% (64/542) screened positive for cognitive impairment, 16% (86/542) were physically frail and 8% (44/542) had cognitive impairment combined with physical frailty, showing an older age (P < 0.001) and a lower education level (P < 0.001) than physically frail patients. A total of 113 patients (20.9%) died or were readmitted at 6 months. Frail participants with a normal (hazard ratio [HR]: 1.73, 95% confidence interval [CI]: 1.06–2.82, P = 0.028) or impaired cognition (HR: 2.50, 95% CI: 1.27–4.91, P = 0.008) had a higher risk of non-elective hospital readmission or death than robust patients after adjusting for the age, sex, education level, marital status, the presence of diabetes mellitus, heart failure, and history of stroke. The area under the ROC curve (AUC) showed that the discriminative ability in relation to 6 months readmission and death for the MMSE + CDT + Fried phenotype was 0.65 (95% CI: 0.60–0.71), and the AUC for men was 0.71 (95% CI: 0.63–0.78), while that for women was 0.60 (95% CI: 0.51–0.69).

Conclusions

Accounting for cognitive impairment in the frailty phenotype may allow for the better prediction of non-elective hospital readmission or death in elderly inpatients with CVD in the short term.

Trial registration

ChiCTR1800017204; date of registration: 07/18/2018.

Low Mood and Risk of Dementia: The Role of Marital Status and Living Situation

OBJECTIVE

This study aims to explore whether low mood is related to an increased dementia risk in two cohorts of older adults of different generations, and whether marital status and living situation modify this association.

METHODS

Participants (≥70 years), free from dementia and living at home, were identified from two population-based studies: the Kungsholmen Project (KP; n = 1,197) and the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K; n = 1,402). Low mood was obtained by self-report (KP and SNAC-K) at baseline in 1987-89 (KP) and 2001-04 (SNAC-K). Incident dementia cases were ascertained over 9 years, using the same diagnostic procedures and comparable criteria for the two cohorts (DSM-III-R in KP and DSM-IV-TR in SNAC-K). Hazard ratios (HR) were derived from Cox proportional hazards models.

RESULTS

Those having low mood at baseline were at higher risk of dementia in both cohorts combined (HR: 1.2, 95% confidence interval (CI): 1.0-1.4) than those without low mood. However, an increased risk was detected only in those who did not have a partner (HR: 1.5, 95% CI: 1.2-1.9), or lived alone (HR: 1.5, 95% CI: 1.2-1.9), but not among those who had a partner or lived with someone (HR: 0.8, 95% CI: 0.5-1.2).

CONCLUSION

Marital status and living situation have the potential to buffer the detrimental effects of low mood on dementia onset. Thus, specific attention from health care should target individuals having low mood and who do not have a partner or live alone.

Is the prevalence of psychosis in the very old decreasing? A comparison of 85-year-olds born 22 years apart

OBJECTIVE

To elucidate whether there is a decrease of psychotic symptoms in 85-years-olds without dementia and if factors associated with psychotic symptoms have changed, we studied two birth cohorts of 85-year-olds born 22 years apart.

METHODS

Every second, 85-year-olds in Gothenburg, Sweden was invited to neuropsychiatric examinations in 1986 to 1987 (participation 63.1%, N = 494) and in 2008 to 2010 (60.5%, N = 571). A close informant was interviewed by a psychiatrist or a research psychologist.

RESULTS

The prevalence of psychotic symptoms in 85-years-olds without dementia decreased from 10.1% in 1986 to 1987 to 3.2% in 2008 to 2010 (P < .001). Disability in daily life (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.1-4.5), depressed mood (OR, 3.9; 95% CI, 2.1-7.1), irritability (OR, 3.6; 95% CI, 1.2-10.5), and suicidal ideation (OR, 4.1; 95% CI, 2.1-8.0) were associated with psychotic symptoms in both cohorts. Mean mini-mental state examination (MMSE) score was lower in those with psychotic symptom compared with those with no psychotic symptoms (Cohort 1986-1987, 26.4 vs 27.8, Cohort 2008-2009, 26.1 vs 27.7, t value -4.24, Pr > t < 0.001).

CONCLUSION

The prevalence of psychotic symptoms decreased between 1986 to 1987 and 2008 to 2010 among 85-years-olds without dementia. These symptoms were associated with broad psychopathology, worse performance in cognitive testing, and with disability of daily life in both cohorts.

Secular Trends in Dementia Prevalence and Incidence Worldwide: A Systematic Review

BACKGROUND

Time trends for dementia prevalence and incidence rates have been reported over the past seven decades in different countries and some have reported a decline.

OBJECTIVE

To undertake a systematic review to critically appraise and provide an evidence-based summary of the magnitude and direction of the global changes in dementia prevalence and incidence across time.

METHODS

Medline, EMBASE, and PsychINFO were searched for studies focused on secular trends in dementia prevalence and/or incidence until 18 December 2017. In total, 10,992 articles were identified and 43 retained.

RESULTS

Overall, prevalence rates are largely increasing (evidence primarily from record-based surveys and cohort studies in Japan, Canada, and France) or have remained stable (evidence primarily from cohort studies in Sweden, Spain and China). A significant decline in prevalence has however been reported in more recent studies (i.e., from 2010 onwards) from Europe (e.g., UK and Sweden) and the USA. Incidence rates have generally remained stable or decreased in China, Canada, France, Germany, Denmark, Sweden, the Netherlands, UK, and USA. An increase has only been reported in five countries: Italy, Japan, Wales, Germany, and the Netherlands. Only one study reported findings (stability in incidence) from a low and middle-income country using data from Nigeria.

CONCLUSIONS

The evidence on secular trends in the prevalence and incidence of dementia is mixed including contradictory findings using different (and in some cases the same) datasets in some countries (e.g., the USA, UK, and Sweden). This making it difficult to draw concrete conclusions. However, declining trends recently observed in some high-income Western countries in the most recent two decades including the UK, USA, and Sweden are encouraging. Updated dementia prevalence and incidence estimates will inform public health and financial planning as well as development of prevention strategies.

Declining Incident Dementia Rates Across Four Population-Based Birth Cohorts

BACKGROUND

Incidence rates of dementia appear to be declining in high-income countries according to several large epidemiological studies. We aimed to describe declining incident dementia rates across successive birth cohorts in a U.S. population-based sample and to explore the influences of sex and education on these trends.

METHODS

We pooled data from two community-sampled prospective cohort studies with similar study aims and contiguous sampling regions: the Monongahela Valley Independent Elders Survey (1987-2001) and the Monongahela-Youghiogheny Healthy Aging Team (2006-Ongoing). We identified four decade-long birth cohorts spanning birth years 1902-1941. In an analysis sample of 3,010 participants (61% women, mean baseline age = 75.7 years, mean follow-up = 7.1 years), we identified 257 cases of incident dementia indicated by a Clinical Dementia Rating of 1.0 or higher. We used Poisson regression to model incident dementia rates by birth cohort, age, sex, education, and interactions of Sex × Cohort and Sex × Education. We further examined whether cohort effects varied by education, testing a Cohort × Education interaction and stratifying the models by education.

RESULTS

Compared to the earliest birth cohort (1902-1911), each subsequent cohort had a significantly lower incident dementia rate (1912-1921: incidence rate ratio [IRR] = 0.655, 95% confidence interval [95% CI] = 0.477-0.899; 1922-1931: IRR = 0.387, 95% CI = 0.265-0.564; 1932-1941: IRR = 0.233, 95% CI = 0.121-0.449). We observed no significant interactions of either sex or education with birth cohort.

CONCLUSIONS

A decline in incident dementia rates was observed across successive birth cohorts independent of sex, education, and age.

Depression and neuroticism decrease among women but not among men between 1976 and 2016 in Swedish septuagenarians

OBJECTIVES

We evaluated birth-cohort differences in depressive symptom burden, prevalence of depression diagnoses, and neuroticism, among Swedish 70-year-olds examined between 1976 and 2016.

METHODS

We used a repeated cross-sectional design examining four representative population samples of Swedish 70-year-olds (total n = 2279) with identical methods in 1976-77 (n = 392), 1992-93 (n = 226), 2000-02 (n = 487), and 2014-16 (n = 1166). Depressive symptom burden was rated with the Montgomery Åsberg Depression Rating Scale. Major depression was diagnosed according to DSM-5, and minor depression according to DSM-IV-TR research criteria. Neuroticism was rated with the Eysenck Personality Inventory.

RESULTS

For women in 2014-16, MADRS score (4.4 vs. 6.1 vs. 5.8; P < 0.05) and neuroticism (6.6 vs. 7.7 vs. 9.2; P < 0.05) were lower compared with 1992-93 and 1976-77, and the prevalence of any depression was lower compared with 2000-02 and 1992-93 (10.9% vs. 16.9% vs. 18.1%; P < 0.05). For men, we observed no birth-cohort differences in depression, while neuroticism was found to be lower in 2014-16 compared with 1976-77 among men without depression (5.1 vs. 5.9; P < 0.01). The sex difference for MADRS and neuroticism declined between 1976-77 and 2014-16 (cohort*sex P < 0.05).

CONCLUSIONS

Depressive burden and neuroticism decreased in 70-year-old women between 1976 and 2016.

Cognitive decline and mortality among community-dwelling Chinese older people

BACKGROUND

Whether cognitive decline is related to a higher risk of death independent of the initial cognitive function is inconclusive. Evidence of the association between cognitive decline and mortality among Chinese older people is limited. We aimed to examine whether cognitive decline, assessed by the rate of decrease in the Mini-Mental State Examination (MMSE) score, was associated with mortality independent of initial cognitive function (baseline MMSE score) among Chinese older people.

METHODS

We established two successive and non-overlapping cohorts of older adults nested within the Chinese Longitudinal Healthy Longevity Survey (CLHLS), an ongoing, open, community-based cohort survey conducted every 2-3 years. Cognitive function was measured using the Chinese version of the MMSE. A total of 11,732 older adults who completed two consecutive cognitive function examinations were included and followed for 3 years. A Cox proportional hazards model was used to examine the association of cognitive decline with mortality after adjusting for sociodemographic characteristics, health behaviours, comorbidities and initial cognitive function.

RESULTS

The mean age was 82.5 years old, and 44.9% (5264/11732) of participants were men. After adjusting for baseline MMSE scores and other covariates, the rate of change in MMSE scores over 3 years was monotonically and positively associated with subsequent 3-year mortality. Compared to those with stable cognitive function, participants with rapid cognitive decline (decline faster than average, a reduction of MMSE scores > 1.62 points/year) had a 75% higher risk of death (hazard ratio = 1.75, 95% confidence interval 1.57-1.95). The association between cognitive decline and mortality was stronger among relatively younger Chinese older people (aged 65-79 years versus 80 years and over) and those with normal cognitive function at baseline (MMSE scores ≥ 24 versus < 24 points), respectively, but did not differ by cohort and sex.

CONCLUSION

Faster cognitive decline was associated with higher mortality independent of initial cognitive function, especially among those aged 65-79 years and those with normal cognitive function at baseline. The association was consistent across two successive cohorts. Our findings indicate the practical significance of monitoring cognitive change in older adults.

Differences in cognitive performance and cognitive decline across European regions: a population-based prospective cohort study

BACKGROUND

A large variation in cognitive performance exists between European regions. However, it is unclear how older Europeans differ in the rate of cognitive decline.

METHODS

We analysed data from 22 181 individuals (54% women; median age 71) who participated in the Survey on Health, Ageing and Retirement in Europe. Cognition was measured using tests on verbal fluency, immediate and delayed recall. We used linear regression and linear mixed effects regression to examine regional differences in the level of cognitive performance and the rate of cognitive decline.

RESULTS

Scandinavians had the highest baseline cognitive scores (mean standardized overall cognitive score 0.3), followed by Western Europeans (mean 0.2), Central and Eastern Europeans (mean 0.1) and individuals from Mediterranean countries (mean -0.4). These differences persisted even after adjustment for sociodemographic and clinical characteristics. The annual cognitive decline in Scandinavia (0.59%) was approximately two times greater than in Western Europe (0.28%), Central and Eastern Europe (0.25%) and Mediterranean countries (0.23%).

DISCUSSION

There are substantial differences in cognitive performance as well as rates of cognitive decline among the elderly throughout European regions. This might be explained by differing levels of cognitive reserve.

The Gothenburg H70 Birth cohort study 2014-16: design, methods and study population

To improve health care for older persons, we need to learn more about ageing, e.g. identify protective factors and early markers for diseases. The Gothenburg H70 Birth Cohort Studies (the H70 studies) are multidisciplinary epidemiological studies examining representative birth cohorts of older populations in Gothenburg, Sweden. So far, six birth cohorts of 70-year-olds have been examined over time, and examinations have been virtually identical between studies. This paper describes the study procedures for the baseline examination of the Birth cohort 1944, conducted in 2014–16. In this study, all men and women born 1944 on specific dates, and registered as residents in Gothenburg, were eligible for participation (n = 1839). A total of 1203 (response rate 72.2%; 559 men and 644 women; mean age 70.5 years) agreed to participate in the study. The study comprised sampling of blood and cerebrospinal fluid, psychiatric, cognitive, and physical health examinations, examinations of genetics and family history, use of medications, social factors, functional ability and disability, physical fitness and activity, body composition, lung function, audiological and ophthalmological examinations, diet, brain imaging, as well as a close informant interview, and qualitative studies. As in previous examinations, data collection serves as a basis for future longitudinal follow-up examinations. The research gained from the H70 studies has clinical relevance in relation to prevention, early diagnosis, clinical course, experience of illness, understanding pathogenesis and prognosis. Results will increase our understanding of ageing and inform service development, which may lead to enhanced quality of care for older persons.

Temporal Trends in the Level and Decline of Cognition and Disability in an Elderly Population: The PAQUID Study

In line with declining trends in dementia incidence, we compared the cognitive and functional evolution of 2 "generations" of elderly individuals aged 78-88 years, who were included 10 years apart in the French Personnes Agées Quid cohort (n = 612 in 1991-1992 and n = 628 in 2001-2002) and followed-up for 12 years with assessments of cognition and disability. The impact of specific risk factors on this evolution was evaluated. Differences between the generations in baseline levels and decline over time were estimated using a joint model to account for differential attrition. Compared with the first generation, the second generation had higher performances at baseline on 4 cognitive tests (from P < 0.005). Differences in global cognition, verbal fluency, and processing speed, but not in working memory, were mostly explained by improvement in educational level. The second generation also exhibited less cognitive decline in verbal fluency and working memory. Progression of disability was less over the follow-up period for the second generation than for the first. The cognitive state of this elderly population improved, partially due to improvements in educational level.

Secular Trends in Cognitive Performance in Older Black and White U.S. Adults, 1993-2012: Findings From the Chicago Health and Aging Project

Objective

To characterize secular trends from 1993 to 2012 in cognitive performance using a cohort of older black and white U.S. adults, and compare trends by race.

Method

Our data come from 8,906 participants of the Chicago Health and Aging Project (CHAP), a longitudinal, population-based cohort (age ≥ 67, 60% black). Participants underwent cognitive assessments in six 3-year study cycles from 1993 to 1996 through 2010 to 2012. We computed 3 measures of cognitive performance: global cognition, episodic memory, and perceptual speed.

Results

Mean performance in terms of global cognitive score followed a secular pattern of modest decline over the 6 study cycles. The trend was most pronounced for perceptual speed. Mean scores among black participants were consistently lower than those for whites; these disparities in mean performance narrowed over time, especially on perceptual speed, but appeared to widen at the last cycle. Global scores among the upper quartile of performers rose slightly, but scores among the lowest quartile of performers dropped precipitously.

Discussion

Between 1993 and 2012, secular trends in cognitive performance in this established cohort did not follow a clear pattern of improvement, contrasting with previous research. But patterns differed by cognitive domain, performance level, and race.

Changes in the Lethality of Frailty Over 30 Years: Evidence From Two Cohorts of 70-Year-Olds in Gothenburg Sweden

Background

With aging, health deficits accumulate: people with few deficits for their age are fit, and those with more are frail. Despite recent reports of improved health in old age, how deficit accumulation is changing is not clear. Our objectives were to evaluate changes over 30 years in the degree of deficit accumulation and in the relationship between frailty and mortality in older adults.

Methods

We analyzed data from two population based, prospective longitudinal cohorts, assembled in 1971-1972 and 2000-2001, respectively. Residents of Gothenburg Sweden, systematically drawn from the Swedish population registry. The 1901-1902 cohort (N = 973) had a response rate of 84.8%; the 1930 cohort (N = 500) had a response rate of 65.1%. A frailty index using 36 deficits was calculated using data from physical examinations, assessments of physical activity, daily, sensory and social function, and laboratory tests. We evaluated mortality over 12.5 years in relation to the frailty index.

Results

Mean frailty levels were the same (x¯ = 0.20, p = .37) in the 1901-1902 cohort as in the 1930 cohort. Although the frailty index was linked to the risk of death in both cohorts, the hazards ratio decreased from 1.67 per 0.1 increment in the frailty index for the first cohort to 1.32 for the second cohort (interaction term p = .005).

Discussion

Although frailty was as common at age 70 as before, its lethality appears to be less. Just why this is so should be explored further.

Decreasing prevalence of dementia in 85-year olds examined 22 years apart: the influence of education and stroke

Individuals aged 80 years and older constitute the fastest growing segment of the population worldwide, leading to an expected increase in dementia cases. Education level and treatment of vascular risk factors has increased during the last decades. We examined whether this has influenced the prevalence of dementia according to DSM-III-R using population-based samples of 85-year-olds (N = 1065) examined with identical methods 1986–87 and 2008–10. The prevalence of dementia was 29.8% in 1986–87 and 21.7% in 2008–10 (OR 0.66; 95%-CI: 0.50–0.86). The decline was mainly observed for vascular dementia. The proportion with more than basic education (25.2% and 57.7%), and the prevalence of stroke (20% and 30%) increased, but the odds ratio for dementia with stroke decreased from 4.3 to 1.8 (interaction stroke*birth cohort; p = 0.008). In a logistic regression, education (OR 0.70; 95%-CI 0.51–0.96), stroke (OR 3.78; 95%-CI 2.28–6.29), interaction stroke*birth cohort (OR 0.50; 95%-CI 0.26–0.97), but not birth cohort (OR 0.98; 95%-CI 0.68–1.41), were related to prevalence of dementia. Thus, the decline in dementia prevalence was mainly explained by higher education and lower odds for dementia with stroke in later born birth cohorts. The findings may be related to an increased cognitive reserve and better treatment of stroke in later-born cohorts.

A scoping review of Finnish doctoral dissertations in older people nursing science

Scientific research is important in guiding the development of evidence-based, cost-effective and comprehensive healthcare. The purpose of this scoping review was to analyse the current stage of research in the field of older people nursing science based on doctoral dissertations completed in Finnish universities. Altogether 418 doctoral dissertations in nursing science were published (1990–2015), and 44 of these (11%) represented older people nursing. The majority of the dissertations focused on patient and family or nursing activities. Usual topics were care procedures and clinical nursing (36%); self-care ability, independence (23%) and existence, being and feeling as an individual person (18%). Only one randomised controlled trial was conducted. The main informants were older people (78%) who were typically interviewed or surveyed. Research in older people nursing science in Finland is focusing on traditional clinical nursing settings. More innovative research is necessary from the perspective of health promotion and technological solutions.

Dementia incidence trend over 1992-2014 in the Netherlands: Analysis of primary care data

BACKGROUND

Recent reports have suggested declining age-specific incidence rates of dementia in high-income countries over time. Improved education and cardiovascular health in early age have been suggested to be bringing about this effect. The aim of this study was to estimate the age-specific dementia incidence trend in primary care records from a large population in the Netherlands.

METHODS AND FINDINGS

A dynamic cohort representative of the Dutch population was composed using primary care records from general practice registration networks (GPRNs) across the country. Data regarding dementia incidence were obtained using general-practitioner-recorded diagnosis of dementia within the electronic health records. Age-specific dementia incidence rates were calculated for all persons aged 60 y and over; negative binomial regression analysis was used to estimate the time trend. Nine out of eleven GPRNs provided data on more than 800,000 older people for the years 1992 to 2014, corresponding to over 4 million person-years and 23,186 incident dementia cases. The annual growth in dementia incidence rate was estimated to be 2.1% (95% CI 0.5% to 3.8%), and incidence rates were 1.08 (95% CI 1.04 to 1.13) times higher for women compared to men. Despite their relatively low numbers of person-years, the highest age groups contributed most to the increasing trend. There was no significant overall change in incidence rates since the start of a national dementia program in 2003 (-0.025; 95% CI -0.062 to 0.011). Increased awareness of dementia by patients and doctors in more recent years may have influenced dementia diagnosis by general practitioners in electronic health records, and needs to be taken into account when interpreting the data.

CONCLUSIONS

Within the clinical records of a large, representative sample of the Dutch population, we found no evidence for a declining incidence trend of dementia in the Netherlands. This could indicate true stability in incidence rates, or a balance between increased detection and a true reduction. Irrespective of the exact rates and mechanisms underlying these findings, they illustrate that the burden of work for physicians and nurses in general practice associated with newly diagnosed dementia has not been subject to substantial change in the past two decades. Hence, with the ageing of Western societies, we still need to anticipate a dramatic absolute increase in dementia occurrence over the years to come.

Cohort effects in verbal memory function and practice effects: a population-based study

BACKGROUND

In many developed countries, cognitive functioning (as measured by neuropsychological tests) appears to be improving over time in the population at large, in parallel with the declining age-specific incidence of dementia. Here, we investigated cohort effects in the age-associated trajectories of verbal memory function in older adults. We sought to determine whether they varied by decade of birth and, if so, whether the change would be explained by increasing educational attainment.

METHODS

Pooling data from two prospective US population-based studies between 1987 and 2015, we identified four birth cohorts born 1902-1911, 1912-1921, 1922-1931, and 1932-1943. Among these cohorts, we compared age-associated trajectories both of performance and of practice effects on immediate and delayed recall of a 10-item Word List. We used mixed effects models, first including birth cohorts and cohort X age interaction terms, and then controlling for education and education X age interaction.

RESULTS

We observed significant cohort effects in performance (baseline and age-associated trajectories) in both immediate recall and delayed recall, with function improving between the earliest- and latest-born cohorts. For both tests, we also observed cohort effects on practice effects with the highest levels in the latest-born cohorts. Including education in the models did not attenuate these effects.

CONCLUSIONS

In this longitudinal population study, across four decade-long birth cohorts, there were significant improvements in test performance and practice effects in verbal memory tests, not explained by education. Whether this reflects declining disease incidence or other secular trends awaits further investigation.

Time Trends in Murray's Psychogenic Needs over Three Decades in Swedish 75-Year-Olds

BACKGROUND

While time trends in personality traits have been suggested in younger cohorts, little is known regarding this issue in older adults.

OBJECTIVE

To test for birth cohort changes in psychogenic needs according to Murray's theory of personality in two birth cohorts of 75-year-olds born 1901-1902 and 1930.

METHODS

Two population-based birth cohorts were examined at the age of 75 years in 1976-1977 and in 2005-2006. Psychogenic needs according to Murray were measured with the Cesarec-Marke Personality Schedule (CMPS), a Swedish version of the Edwards Personal Preference Schedule. Scores on the CMPS subscales (achievement, affiliation, aggression, defence of status, guilt feelings, dominance, exhibition, autonomy, nurturance, order, succorance, and acquiescence) were compared between cohorts.

RESULTS

Achievement, exhibition, dominance, aggression, affiliation, and succorance scores were higher, and order and acquiescence scores lower, in the more recent birth cohort of 75-year-olds. Women scored lower than men on exhibition and dominance, and higher on defence of status, guilt feelings, affiliation, nurturance, and succorance. Interaction effects between cohort and sex were found for achievement (women scored lower than men in 1976-1977 but not in 2005-2006), order (the lower scores in 2005-2006 were more accentuated among men), and acquiescence (increased in men and decreased in women).

CONCLUSION

The later-born birth cohort scored higher on self-centred traits, such as more dominant, competitive, and exhibitive traits as well as the need to be taken care of and have friends around, but it scored lower on the need for order. The gap between men and women regarding achievement decreased, possibly reflecting women's more prominent role in society.

Dementias

This chapter will focus on the descriptive, analytic, and intervention-oriented epidemiology of dementia and its most frequent etiologic type due to Alzheimer's disease. The chapter opens with a brief presentation of the concept of dementia, followed by the presentation of dementia of the Alzheimer type (DAT), including natural history, clinical manifestation, neuropathology, medical prognosis, and management. Further, the chapter presents the prevalence and incidence of dementia, with special consideration of secular trends in prevalence and incidence of DAT, and prognosis of the socioeconomic impact of dementia. Thereafter the main risk factors for DAT are covered. The chapter also addresses the results of ongoing therapeutic and preventive intervention trials for DAT. Finally, the future challenges of the epidemiology of dementia with a focus on the impact of the new diagnostic criteria for neurocognitive disorders, as well as the development of biomarkers for DAT and other types of dementia, will be briefly discussed.

Population Aging at Cross-Roads: Diverging Secular Trends in Average Cognitive Functioning and Physical Health in the Older Population of Germany

This paper uses individual-level data from the German Socio-Economic Panel to model trends in population health in terms of cognition, physical fitness, and mental health between 2006 and 2012. The focus is on the population aged 50–90. We use a repeated population-based cross-sectional design. As outcome measures, we use SF-12 measures of physical and mental health and the Symbol-Digit Test (SDT) that captures cognitive processing speed. In line with previous research we find a highly significant Flynn effect on cognition; i.e., SDT scores are higher among those who were tested more recently (at the same age). This result holds for men and women, all age groups, and across all levels of education. While we observe a secular improvement in terms of cognitive functioning, at the same time, average physical and mental health has declined. The decline in average physical health is shown to be stronger for men than for women and found to be strongest for low-educated, young-old men aged 50–64: the decline over the 6-year interval in average physical health is estimated to amount to about 0.37 SD, whereas average fluid cognition improved by about 0.29 SD. This pattern of results at the population-level (trends in average population health) stands in interesting contrast to the positive association of physical health and cognitive functioning at the individual-level. The findings underscore the multi-dimensionality of health and the aging process.

Loneliness of older people aged 70: a comparison of two Finnish cohorts born 20 years apart

OBJECTIVE

This study aimed to examine loneliness among two birth cohorts, born 20 years apart, when they were 70 years of age, and to identify factors explaining loneliness.

METHODS

The cohorts consisted of older home-dwelling residents of Turku, Finland, from the birth cohort 1920 in 1991 (N=1530) and the birth cohort 1940 in 2011 (N=1307). Suffering from loneliness was assessed with the question: 'Do you suffer from loneliness?' Cross-tabulations with chi-square test, general linear model (GLM) and multiple regression analysis were used in statistical testing and modeling.

RESULTS

In the 1940 cohort, around one-fifth (18%) of the respondents suffered from loneliness at least sometimes, while the corresponding figure in the 1920 cohort was around one-fourth (26%). Our analyses indicated that the effect of cohort was not a statistically significant explanatory factor of loneliness. Living status, self-rated health and memory compared to age peers were statistically significant explanatory factors for suffering from loneliness. When we controlled the effect of depressiveness on the experience of loneliness, it was shown that the effects of living status and self-rated health remained statistically significant, whereas memory compared to age peers did not. Depressiveness itself was highly important. The combined effect of living status and self-rated health emerged as the most significant explanatory factor for loneliness. Older people with poor self-rated health who lived alone were most likely to suffer from loneliness.

CONCLUSION

The findings give healthcare professionals an opportunity to plan for interventions aimed at combating loneliness among home-dwelling older people.

Influence of socio-demographic features and apolipoprotein E epsilon 4 expression on the prevalence of dementia and cognitive impairment in a population of 70-74-year olds: the InveCe.Ab study

The age-specific prevalence rates of dementia vary widely. Studies focusing on specific age groups are needed to provide reliable estimates for healthcare providers and policy makers. We estimated the prevalence of dementia, dementia subtypes and cognitive impairment in "InveCe.Ab" (ClinicalTrials.gov, NCT01345110), a single-step multidimensional population-based study of 70-74-year olds living in Abbiategrasso (Milan, Italy). We also looked for associations with socio-demographic factors and the presence of the apolipoprotein E-ɛ4 allele. The overall dementia prevalence was 3% (95%CI: 2.1-4.1%) [Alzheimer's disease (AD): 1.2% (95%CI 0.6-1.9%); vascular dementia (VD): 1.4% (95%CI: 0.8-2.2%)]. Being single was found to be a risk factor for vascular dementia; subjects born in southern Italy were shown to be at greater risk both of overall dementia and of vascular dementia. The prevalence of cognitive impairment, with or without subjective cognitive complaints (cognitive impairment, no dementia, CIND) was 7.8% (95%CI: 6.4-9.4%). As regards the CIND subgroups, the prevalence of subjects with subjective cognitive complaints (mild cognitive impairment, MCI) was 5.0% (95%CI 3.9-6.3%), while the prevalence of those without MCI (CIND-other) was 2.8% (95%CI: 1.9-3.8). The males had a higher risk of MCI and CIND-other; the older subjects were more likely to have MCI, and those born in north-eastern Italy to have CIND-other. The prevalence of AD was higher among the apolipoprotein E-ɛ4 carriers. Our data highlight the importance of dementia and cognitive impairment in the transitional period from adulthood to old age, and reveal the presence of different associations with socio-demographic and genetic factors.

Secular trends in the prevalence of dementia and depression in Swedish septuagenarians 1976-2006

BACKGROUND

It is not clear whether the prevalence of dementia and depression among the elderly has changed during the past 30 years.

METHOD

Population-based samples from Gothenburg, Sweden were examined with identical psychiatric and neuropsychiatric examinations at age 70 years in 1976-1977 (n = 404, response rate 78.8%) and 2000-2001 (n = 579, response rate 66.4%), and at age 75 in 1976-1977 (n = 303, response rate 78%) and 2005-2006 (n = 753, response rate 63.4%). Depression was diagnosed according to DSM-IV and dementia according to Kay's criteria. General linear models (GLMs) were used to test for differences between groups.

RESULTS

Dementia was related to age but not to birth cohort or sex. Major depression was related to sex (higher in women) but not to birth cohort or age. Minor depression was related to birth cohort, sex (higher in women), age (higher at age 75) and the interaction effect of birth cohort × age; that is, the prevalence of minor depression increased with age in the 2000s but not in the 1970s. Thus, the prevalence of minor depression was higher in 2005-2006 than in 1976-1977 among 75-year-olds for both men (12.4% v. 3.7%) and women (19.1% v. 5.6%) whereas there were no birth cohort differences at age 70.

CONCLUSIONS

Secular changes were observed only for minor depression, which is considered to be related more to psychosocial factors than major depression. The high prevalence of minor depression in later-born birth cohorts emphasizes the importance of detecting minor depression in the elderly.

Cohort effects in age-associated cognitive trajectories

BACKGROUND

The age-specific prevalence and incidence of dementia and cognitive impairment in the United States have either remained stable or even slightly declined during the 1980s-1990s. A suggested but untested reason for this improvement in cognitive function over time is higher educational attainment among more recent cohorts.

METHODS

We used data from two large prospective population-based epidemiological dementia studies conducted in two adjacent regions during the period 1987-2012. We examined whether (i) cohort effects could be observed in age-associated trajectories of cognitive functions and (ii) the observed cohort effects could be explained by educational attainment. Trajectories of neuropsychological tests tapping three domains (psychomotor speed, executive function, and language) were compared among cohorts born between 1902 and 1911, 1912 and 1921, 1922 and 1931, and 1932 and 1943. We examined Age × Cohort interactions in mixed-effects models with/without controlling for education effects.

RESULTS

Cohort effects in age-associated trajectories were observed in all three domains, with consistent differences between the earliest born cohort and the most recent cohort. Executive functions showed the strongest and persistent differences between the most recent and other three cohorts. Education did not attenuate any of these associations.

CONCLUSIONS

Cohort effects were observed in all examined cognitive domains and, surprisingly, remained significant after controlling for educational effects. Factors other than education are likely responsible for the cohort effects in cognitive decline.

Determinants of sexual activity in four birth cohorts of Swedish 70-year-olds examined 1971-2001

INTRODUCTION

Knowledge about determinants of sexual activity in older adults in the general population is limited. Human senescence has been delayed by a decade, and people are reaching old age in better health.

AIM

The aim of this study was to investigate determinants of sexual activity in four birth cohorts of non-demented 70-year-olds examined in 1971-1977 and 1992-2001.

MAIN OUTCOME MEASURE

The main outcome measure was sexual activity (defined as intercourse) during the past year.

METHODS

The study is based on cross-sectional data from four population samples of 70-year-olds from Gothenburg, Sweden (N = 1,407) systematically sampled from the Swedish population register.

RESULTS

In the time periods 1971-1972 and 2000-2001, sexual activity among men increased from 47% to 66%, and in women from 12% to 34%. Sexual activity was related to positive attitude toward sexuality, sexual debut before age 20, having a very happy relationship, having a physically and mentally healthy partner, self-reported good global health, interviewer-rated good mental health, being married/cohabiting, satisfaction with sleep, and drinking alcohol more than three times a week. Having an older partner, diabetes mellitus, coronary heart disease, higher physical health-sum score, and depression were related to less sexual activity. Interaction effects for birth cohort, with stronger positive associations in 1971-1972, were found for positive attitude toward sexuality, strong desire at age 20-30, premarital sexuality, having a younger partner, self-reported good global health, interviewer-rated good global mental health, overweight, and satisfaction with sleep. Having an older partner and depression showed stronger negative associations in the 1970s. Physical health-sum score showed a stronger negative association in 1992-2001.

CONCLUSIONS

We found that determinants of sexual activity in older people are numerous and varied, and change over time. It is thus important that health professionals and others take a holistic approach when dealing with sexual problems in older adults. Sexual aging should be part of health care and medical education. Clinicians should be trained to ask older patients about sexual concerns.

Secular changes in the relation between social factors and depression: a study of two birth cohorts of Swedish septuagenarians followed for 5 years

BACKGROUND

Rapid societal changes occurred in the Western world during the 20(th) century. It is not clear whether this has changed the relation between social factors and depression in older people.

METHODS

Representative samples of 70-year-olds from Gothenburg, Sweden, were examined with identical psychiatric examinations in 1971-72 (N=392; 226 women and 166 men) and 2000-01 (N=499; 270 women and 229 men). Follow-up studies were conducted after five years. Social factors were obtained by self-report and depression was diagnosed according to DSM-IV-TR.

RESULTS

Feelings of loneliness were related to both concurrent depression at baseline and new depression at follow-up in both birth cohorts. Visits with others than children and neighbours once per month or less, compared to having more visits, and the perception of having too little contact with others, were related to both concurrent and new depression in 70-year-olds examined 1971-72, but not in those examined 30 years later.

LIMITATIONS

The response rate declined from 85.2% in 1971-72 to 65.8% in 2000-01. Participation bias may have resulted in an underestimation of depression in the later-born cohort.

CONCLUSIONS

Social contacts with others were related to depression in 70-year-olds examined in the 1970s, but not in those examined in the 2000s. This may reflect period changes in the ways of socialising, communicating and entertaining, e.g. due to technological development and expansion of mass media. Findings may be useful when developing modern and effective programs for the prevention of mental ill-health in older people.

Secular changes in personality: study on 75-year-olds examined in 1976-1977 and 2005-2006

OBJECTIVE

In order to study secular changes in personality factors neuroticism and extroversion, representative population samples of non-demented 75-year-olds underwent psychiatric examinations in 1976-1977 (total n = 223, 138 women, 85 men) and 2005-2006 (total n = 556, 322 women and 234 men).

METHODS

Eysenck Personality Inventory was used at both occasions. Demographic factors (educational level, marital status, having children) were registered.

RESULTS

Seventy-five-year-olds examined in 2005-2006 had higher values on extroversion and lower values on the Lie scale compared with those examined in 1976-1977. Neuroticism did not differ between the two birth cohorts. Neuroticism scores were higher in women than in men both in 1976-1977 and 2005-2006, and Lie score was higher in women than in men in 2005-2006.

CONCLUSIONS

Our findings suggest that present cohorts of 75-year-olds are more extroverted and less prone to respond in a socially desirable manner than those born three decades earlier. Neuroticism levels remained unchanged, suggesting this trait may be less influenced by environmental factors than the other traits studied.

Secular trends in lung function and its relation to survival in Swedish 75 year olds 1976-2006

BACKGROUND

several studies have found that lung function correlates with survival in older people. We examined secular trends in lung function and its relation to survival in Swedish 75 year olds.

METHOD

representative samples from the general population in Gothenburg, Sweden, were examined at the age of 75 in 1976-77 (n = 743) and 2005-06 (n = 765) with comprehensive somatic and psychiatric examinations. Lung function was measured as peak expiratory flow (PEF).

RESULTS

the mean PEF was higher in 75 year olds examined 2005-06 compared with those examined 1976-77 both among women (339 versus 307 l/min; P < 0.001) and men (490 versus 400 l/min, P < 0.001). The birth cohort effect was still significant after adjusting for a number of confounders. PEF correlated with survival between age 75 and 78 years among those examined in 1976-77 both in women (OR per 10 l/min increase in PEF = 1.112, 95% CI: 1.047-1.182) and in men (OR = 1.040, 95% CI: 1.015-1.066), but not in those examined 2005-06 (women: OR = 1.071, 95% CI: 0.965-1.188; men: OR = 1.000, 95% CI: 0.957-1.046).

CONCLUSION

we found better lung function in the later-born cohort of 75 year olds, which was only partially explained by changes in smoking, height and weight, physical activity, socio-economic/educational factors and pulmonary/cardiovascular morbidity. The association between better lung function and short-term survival was strong in 1976-77, but had disappeared in 2005-06. More studies are needed to elucidate the role of lung function for long-term survival and identify other factors that explain the secular trends in lung function.

Neuroprotection in vascular dementia: a future path

The burden of cognitive disorders is likely to increase over the coming years due to both increased longevity and altered risk factor patterns, arising from changes in lifestyle, healthcare and society. Vascular dementia with its underlying heterogeneous pathology, is a challenge for clinicians, and is frequently further aggravated by overlap with other neurodegenerative processes. Current Alzheimer's disease drugs have had limited clinical efficacy in treating vascular dementia and none have been approved by major regulatory authorities specifically for this disease. Moving forward, a valid choice may be a multimodal therapy, as has already been successfully proven in Alzheimer's disease. Actovegin, a hemodialysate derived from calf blood, has been shown to have effects on a variety of cellular processes and a recent experimental study has revealed its neuroprotective mechanisms of action. These data, coupled with positive results from clinical trials in mixed dementia populations, have served as a foundation for the design of a new trial investigating the efficacy and disease-modifying effects of Actovegin in post-stroke cognitive impairment.

Variation in cognitive functioning as a refined approach to comparing aging across countries

Comparing the burden of aging across countries hinges on the availability of valid and comparable indicators. The Old Age Dependency Ratio allows only a limited assessment of the challenges of aging, because it does not include information on any individual characteristics except age itself. Existing alternative indicators based on health or economic activity suffer from measurement and comparability problems. We propose an indicator based on age variation in cognitive functioning. We use newly released data from standardized tests of seniors' cognitive abilities for countries from different world regions. In the wake of long-term advances in countries' industrial composition, and technological advances, the ability to handle new job procedures is now of high and growing importance, which increases the importance of cognition for work performance over time. In several countries with older populations, we find better cognitive performance on the part of populations aged 50+ than in countries with chronologically younger populations. This variation in cognitive functioning levels may be explained by the fact that seniors in some regions of the world experienced better conditions during childhood and adult life, including nutrition, duration and quality of schooling, lower exposure to disease, and physical and social activity patterns. Because of the slow process of cohort replacement, those countries whose seniors already have higher cognitive levels today are likely to continue to be at an advantage for several decades to come.

A population-based study on the influence of brain atrophy on 20-year survival after age 85

BACKGROUND

Individuals aged 80 years and older is the fastest growing segment of the population worldwide. To understand the biology behind increasing longevity, it is important to examine factors related to survival in this age group. The relationship between brain atrophy and survival after age 85 remains unclear.

METHODS

A population-based sample (n = 239) had head CT scans at age 85 and was then followed until death. Cortical atrophy and ventricular size were assessed. Statistical analyses included Cox proportional hazards models with time to death as the outcome and considering a large number of possible confounders, including baseline cognitive function, incident dementia, and somatic disorders.

RESULTS

Mean survival time (±SD) was 5.0 ± 3.6 years (range 0.10-19.8 years). Decreased survival was associated with temporal, and frontal atrophy, sylvian fissure width and a number of ventricular measures after adjustment for potential confounders. In participants without dementia at baseline (n = 135), decreased survival was associated with temporal lobe atrophy and bifrontal ratio. In those with dementia (n = 104), decreased survival was associated with third ventricle width, cella media ratio, and ventricle-to-brain and ventricle-to-cranial ratio.

CONCLUSIONS

Several indices of brain atrophy were related to decreased survival after age 85, regardless of dementia status. Brain atrophy is rarely mentioned as a significant indicator of survival in the elderly, independent of traditional predictors such as cardiovascular disease or cancer. The biology behind the influence of brain atrophy on survival needs to be further scrutinized.