The prevalence of cognitive impairment with no dementia in older people: the Seoul study

Carvalho O, Barros H. Global Cognitive Impairment Prevalence and Incidence in Community Dwelling Older Adults-A Systematic Review

(1) Background: We proposed to review worldwide estimates of cognitive impairment prevalence and incidence in adults older than 50 years of age living in the community. (2) Methods: Systematic searches were performed in January 2019 using MEDLINE/PubMed. Articles were selected if they referred to cognitive impairment, prevalence, incidence, elders, and population or community-based studies. Analysis, aggregated by different methodologic features, was performed. (3) Results: Prevalence (80 studies) ranged between 5.1% and 41% with a median of 19.0% (25th percentile = 12.0%; 75th percentile = 24.90%). Incidence (11 studies) ranged from 22 to 76.8 per 1000 person-years with a median of 53.97 per 1000 person-years (25th percentile = 39.0; 75th percentile = 68.19). No statistically significant effects were found except for inclusion age. (4) Conclusion: We propose that the homogenization and clarification of the definition of what constitutes cognitive impairment are essential to refine the epidemiological understanding of this entity. The results of this review reinforce the importance of adherence to standardized cut-off scores for cognitive tests to promote study comparability.

Development of the ubiquitous spaced retrieval-based memory advancement and rehabilitation training program

OBJECTIVE

The Ubiquitous Spaced Retrieval-based Memory Advancement and Rehabilitation Training (USMART) program was developed by transforming the spaced retrieval-based memory training which consisted of 24 face-to-face sessions into a self-administered program with an iPAD app. The objective of this study was to evaluate the feasibility and efficacy of USMART in elderly subjects with mild cognitive impairment (MCI).

METHODS

Feasibility was evaluated by checking the satisfaction of the participants with a 5-point Likert scale. The efficacy of the program on cognitive functions was evaluated by the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery before and after USMART.

RESULTS

Among the 10 participants, 7 completed both pre- and post-USMART assessments. The overall satisfaction score was 8.0±1.0 out of 10. The mean Word List Memory Test (WLMT) scores significantly increased after USMART training after adjusting for age, educational levels, baseline Mini-Mental Status Examination scores, and the number of training sessions (pre-USMART, 16.0±4.1; post-USMART, 17.9±4.5; p=0.014, RM-ANOVA). The magnitude of the improvements in the WLMT scores significantly correlated with the number of training sessions during 4 weeks (r=0.793; p=0.033).

CONCLUSION

USMART was effective in improving memory and was well tolerated by most participants with MCI, suggesting that it may be a convenient and cost-effective alternative for the cognitive rehabilitation of elderly subjects with cognitive impairments. Further studies with large numbers of participants are necessary to examine the relationship between the number of training sessions and the improvements in memory function.

Differential distribution of subjective and objective cognitive impairment in the population: a nation-wide twin-study

We report the prevalence of subjective cognitive impairment (SCI) and cognitive impairment no dementia (CIND), their socio-demographic profile, and the contribution of genetic background and shared familial environment to SCI and CIND. Subjects were 11,926 dementia-free twin individuals aged ≥65 from the Swedish Twin Registry. SCI was defined as subjective complaint of cognitive change without objective cognitive impairment and CIND was defined according to current criteria. Overall prevalence rates of SCI and CIND were 39% (95% CI 38-39%) and 25% (95% CI 24-25%). In multivariate GEE models, both SCI and CIND were older compared with people without any cognitive impairment. CIND were also less educated, more likely to be unmarried and to have lower socioeconomic status (SES). SCI individuals differed from persons with CIND as they were older, more educated, more likely to be married, and to have higher SES. Co-twin control analysis, which corrects for common genetic and shared environmental background, confirmed the association of low education with CIND. Probandwise concordance for SCI and CIND was 63% and 52% in monozygotic twins, 63% and 50% in dizygotic same-sex twins, and 42% and 29% in dizygotic unlike-sex twins. Tetrachoric correlations showed no significant differences between monozygotic and dizygotic same-sex twins. We conclude that subjective and objective cognitive impairment are both highly prevalent among nondemented elderly yet have distinct sociodemographic profiles. Shared environmental influences rather than genetic background play a role in the occurrence of SCI and CIND.

Prevalence of psychiatric disorders in community-dwelling older men and women with cognitive impairment no dementia: results from the ESA study

OBJECTIVES

To assess the prevalence rate of mood disorders, anxiety disorders, benzodiazepine dependence, and insomnia in older men and women with probable cognitive impairment no dementia (CIND) and to examine the independent associations between each disorder and CIND.

METHOD

Participants were a random sample of community-dwelling individuals aged 65-96 (N = 2414). Semi-structured in-home interviews based on DSM-IV-TR (DSM, Diagnostic and Statistical Manual of Mental Disorders) criteria evaluated the prevalence rates of mood disorders, anxiety disorders, benzodiazepine dependence, and insomnia. Participants were classified as probable CIND based on their Mini-Mental State Examination score using sex, age, and education-stratified cut-offs (lower than the 15th percentile).

RESULTS

In men, 22.7% of individuals with probable CIND and 12.1% of those with normal cognition had at least one psychiatric disorder (crude odds ratio (OR): 2.13, 95% confidence interval (CI): 1.23-3.69). More specifically, mood disorders (3.43, 1.74-6.75), benzodiazepine dependence (5.10, 1.23-21.11), and comorbid anxiety and mood disorders (8.67, 2.00-37.68) were significantly associated with probable CIND, but not anxiety disorders alone and insomnia. The prevalence rate of psychiatric disorders was similar in women with probable CIND (23.1%) and in women without CIND (23.9%; 0.95, 0.64-1.42). No specific psychiatric disorder was significantly associated with probable CIND in women. All associations remained unchanged after adjustments for potential confounders.

CONCLUSIONS

The association between psychiatric disorders and probable CIND appears to be sex-specific. In clinical practice, mood disorders, and benzodiazepine dependence should receive particular attention since these disorders are associated with a condition increasing the risk of dementia.

Emotional distress and cognitive functioning of older couples: a dyadic analysis

OBJECTIVE

This article examines the relationship between cognitive functioning and emotional distress in a sample of 2,684 married couples from the 2006 and 2008 Korean Longitudinal Study of Aging.

METHOD

Using the Center for Epidemiologic Studies Depression (CESD) scale and the Mini-Mental State Exam (MMSE), we analyze the interrelation between emotional and cognitive health for individuals and spouses with with dyadic regression models. We test how emotional distress and cognitive impairment affect each other within individuals and from one spouse to another.

RESULTS

We find emotional distress contributes to cognitive impairment for wives but not for husbands. We also find emotional distress and cognitive impairment in one spouse affects that in the other. We find no evidence that emotional distress effects spouse's cognitive impairment or that the cognitive ability impacts spouses' emotional distress.

DISCUSSION

We discuss the results within the context of existing literature, focusing on the socioeconomic and clinical factors that explain these interrelations.

Socioeconomic status during lifetime and cognitive impairment no-dementia in late life: the population-based aging in the Chianti Area (InCHIANTI) Study

Thousand and twelve dementia-free elderly (60–98 years old) enrolled in the InChianti Study (Italy) were evaluated at baseline (1998–2000) and at 3-year follow-up (2001–2003) with the aim of analyzing the association of lifetime socioeconomic status (SES) with prevalent and incident cognitive impairment no-dementia (CIND). SES was defined from information on formal education, longest held occupation, and financial conditions through life. CIND was defined as age-adjusted Mini-Mental State Examination score one standard deviation below the baseline mean score of participants without dementia. Logistic regression and Cox proportional-hazards models were used to estimate the association of SES with CIND. Demographics,occupation characteristics (i.e., job stress and physical demand), cardiovascular diseases, diabetes, apolipoprotein E (APOE)genotype, smoking, alcohol consumption, depressive symptoms, and C-reactive protein were considered potential confounders.Prevalence of CIND was 17.7%. In the fully adjusted model, low education (OR = 2.1; 95% confidence intervals, CI = 1.4 to 3.2)was associated with prevalent CIND. Incidence rate of CIND was 66.0 per 1000 person-years. Low education (HR = 1.7; 95% CI = 1.04 to 2.6) and manual occupation (HR = 1.9; 95% CI = 1.0 to 3.6) were associated with incident CIND. Among covariates,high job-related physical demand was associated with both prevalent and incident CIND (OR = 1.6; 95% CI = 1.1 to 2.4 and HR= 1.5; 95% CI = 1.0 to 2.3). After stratification for education, manual occupation was still associated with CIND among participants with high education (HR = 2.2; 95% CI = 1.2 to 4.3 versus HR= 1.4; 95% CI = 0.2 to 10.4 among those with low education). Proxy markers of lifetime SES (low education, manual occupation and high physical demand) are cross-sectional correlates of CIND and predict incident CIND over a three-year follow-up.