A clinico-epidemiological study of cognitive function status of community-dwelling elderly

Short-term heart rate variability: A potential approach to frailty assessment in older adults

Objectives

This study aimed to evaluate cardiac autonomic modulation using short-term heart rate variability (HRV) and compare it among frailty statuses in older Indian adults.

Methods

A total of 210 subjects aged 60 years and above were recruited into three groups: frail (n = 70), pre-frail (n = 70), and non-frail (n = 70) from the outpatient department of Geriatric Medicine at a tertiary care hospital in India. Frailty status was assessed using the Rockwood frailty index (FI) criteria. HRV was derived from a 5-min ECG recording of standard limb leads and assessed using time domain, frequency domain, and nonlinear analysis of cardiac interval variability.

Results

The HRV parameters indicative of parasympathetic modulation such as SDNN, SDSD, rMSSD, NN50, pNN50, absolute HF power, and SD1 were significantly lower in frail subjects compared with both pre-frail and non-frail subjects (P < 0.05). Absolute LF power and SD2 were also lower in frail subjects compared with pre-frail and non-frail subjects (P < 0.05). Measures of sympatho-vagal balance (LF/HF and SD1/SD2 ratios) did not show statistical significance. The FI demonstrated negative correlations with all HRV parameters.

Conclusions

Frail individuals exhibit decreased sympathetic and parasympathetic modulation compared with pre-frail and non-frail individuals, although maintaining a balanced sympatho-vagal state. Furthermore, autonomic modulation declines progressively with increasing frailty.

The effect of illiteracy on performance in screening tools for dementia: A meta-analysis

INTRODUCTION

Research indicates that many tools designed for screening dementia are affected by literacy level. The objective of this study was to estimate the overall effects of this confounding factor. A meta-analysis was conducted to evaluate differences in performance in dementia screening tools between literate and illiterate individuals.

METHOD

Electronic databases were searched from 1975 to June 2021 to identify empirical studies examining performance in dementia screening tools in literate and illiterate individuals over 50 years old. Data for effect sizes, participant demographic information, and study information were extracted.

RESULTS

We identified 27 studies methodologically suitable for meta-analysis. Multi-level random-effects modeling demonstrated a significant overall effect, with literate participants scoring significantly higher than illiterate participants (g = -1.2, 95% CI = -1.47, -0.95, p < .001). Moderator analyses indicated significant effects of test type and the presence of cognitive impairment on the extent of the difference in performance between literate and illiterate participants. The difference in performance between groups was smaller in screening tests modified for illiterate individuals (p < .01), and in individuals with cognitive impairment (p < .001).

CONCLUSIONS

Our findings substantiate the unsuitability of many dementia screening tools for individuals who are illiterate. The results of this systematic review and meta-analysis emphasize the need for the development and validation of tools that are suitable for individuals of all abilities.

Systematic review estimating the burden of dementia in the WHO Southeast Asia Region using Bayesian and frequentist approaches

Background

Rapid increase in life expectancy in low- and middle-income countries including the World Health Organization’s Southeast Asia Region (SEAR) has resulted in an increase in the global burden of dementia, which is expected to become a leading cause of morbidity. Accurate burden estimates are key for informing policy and planning. Given the paucity of data, estimates were developed using both a Bayesian methodology and as well as a traditional frequentist approach to gain better insights into methodological approaches for disease burden estimates.

Methods

Seven databases were searched for studies published between 2010-2018 regarding dementia prevalence in SEAR, generating 8 relevant articles. A random-effects model (REM) and a Bayesian normal-normal hierarchical model (NNHM) were used to obtain the pooled prevalence estimate of dementia for people aged 60 and above in SEAR. The latter model was also developed to estimate age-specific dementia prevalence. Using UN population estimates for SEAR, total and age-specific projections of the burden of dementia in 2015, 2020 and 2030 were calculated.

Results

The prevalence of dementia in SEAR was found to be 3% (95% confidence interval (CI) = 2-6%) in those above age 60 based on REM, and 3.1% (95% credible interval = 1.5-5.0%) based on the NNHM. The estimated prevalence varies with age, increasing from 1.6% (95% credible interval = 0.8-2.5%) in people aged 60-69 to 12.4% (95% credible interval = 5.6-20%) in people above the age of 80. The risk of developing dementia increased exponentially with age. The number of people living with dementia in SEAR in 2015 was estimated at 5.51 million (95% credible interval = 2.66-8.82), with projections of 6.66 million (95% credible interval = 3.21-10.7) in 2020 and 9.6 million (95% credible interval = 4.62-15.36) in 2030.

Conclusion

The burden of dementia in SEAR is substantial and will continue to increase rapidly by 2030. The lack of research focusing on dementia in SEAR points to a significant under-recognition of this disease. The projected rise in dementia cases in the future should prompt urgent governmental response to address this growing public health issue. We also argue that given the overall paucity of data for the region, the Bayesian approach offers a promising methodology for improved estimates of disease prevalence and burden and should continue to be explored.

Prevalence of cognitive dysfunction, psychological morbidity and abuse in the community-based elderly population in India

BACKGROUND

The elderly population in India is expected to grow enormously by 2050 owing to an increase in life expectancy. Community-based data on the prevalence of psychological morbidity, abuse and cognitive dysfunction are scarce.

AIMS

To determine the prevalence of cognitive dysfunction, psychological morbidity and abuse in the elderly population in a resettlement colony from East Delhi, India.

METHODS

A cross-sectional study was conducted on the elderly population of a resettlement colony, in East Delhi, comprising 5 blocks and 12 subblocks with a total population of 65 000. The study was carried out within 2 months from April to August 2017. The self-reported questionnaires were administered to detect cognitive dysfunction, psychological morbidity, social support and pattern of abuse.

RESULTS

The mean age of the study subjects was 70.29 years (53.8% were males, 78.8% were married, 86.9% were Hindus and 75% were living with children). A total of 106 subjects (66.6%) belonged to the lower socioeconomic strata with 120 (75%) living with children. Most of the subjects (70.6%) studied below the primary level of education. As detected on Goldberg General Health Questionnaire-12, 56.9% of the subjects had psychological morbidity. On Dementia Assessment by Rapid Test, 33.1% of subjects were screened positive. The pattern of abuse reported was as follows: emotional abuse (16.9%), physical abuse (7.5%), sexual abuse (1.9%) and social neglect (18.1%). The social support score was found to be 46.22 (12.22).

CONCLUSION

The results of this community-based study signify that appropriate steps at the policy level need to be undertaken so that abuse as well as neglect can be prevented. In addition, screening the elderly population helps to detect early cognitive dysfunction, psychological morbidity, abuse victims and individuals with poor support.

Obesity Measures in Relation to Cognition in the Northern Manhattan Study

BACKGROUND

Mid-life obesity is associated with cognitive impairment, though the relationship for late-life obesity is equivocal, and may depend on the anthropometric measure.

OBJECTIVE

We examined the relationship between adiposity and cognition across age categories, cognitive domains, and by measures of obesity in a multi-ethnic population-based cohort.

METHODS

The study included 1,179 Northern Manhattan Study participants with obesity measures at baseline (44% overweight, 30% obese), an initial neuropsychological assessment conducted within 7 years (mean age = 70), and a second cognitive assessment conducted on average 6 years later. Z-scores were derived for cognitive domains (episodic and semantic memory, executive function, processing speed) and averaged to calculate global cognition. Body mass index (BMI) and waist:hip ratio (WHR) were examined in relation to cognitive performance and change over time, stratified by age, using linear regression models adjusting for vascular risk factors.

RESULTS

Among those age<65 years at baseline, greater WHR was associated with worse global cognitive performance at initial assessment and directly associated with decline in performance between assessments. The association with initial performance was strongest for non-Hispanic Whites (beta = -0.155/standard deviation, p = 0.04), followed by non-Hispanic Black/African Americans (beta = -0.079/standard deviation, p = 0.07), and Hispanics (beta = -0.055/standard deviation, p = 0.03). The associations were most apparent for the domains of processing speed and executive function. There was no association for BMI among those <65 years. Among those age ≥65, there was no association for BMI or WHR with cognitive performance at initial assessment nor decline over time.

CONCLUSION

Our results support the detrimental effect of mid-life rather than later life obesity, particularly abdominal adiposity, on cognitive impairment and decline.

Dose-dependent relationships between chronic arsenic exposure and cognitive impairment and serum brain-derived neurotrophic factor

BACKGROUND

Arsenic poisoning is a public health problem worldwide. A few studies have reported the effects of arsenic exposure on adult cognitive function, but with limitations in the subject selection and exposure markers. Moreover, information regarding the association between arsenic exposure and biomarker of cognitive impairment is scarce.

OBJECTIVES

We examined the associations between arsenic exposure and adult cognitive impairment using the Mini-Mental State Examination (MMSE) and the serum levels of brain-derived neurotrophic factor (BDNF), a potential biomarker of cognitive health status.

METHODS

We designed a cross-sectional study that recruited 693 adult (18-60 years old) subjects from the areas of low- and high‑arsenic exposure in rural Bangladesh. The subjects' arsenic exposure levels (drinking water, hair, and nail arsenic concentrations) were measured by inductively coupled plasma-mass spectroscopy. The Bangla version of the MMSE was used as a cognitive assessment tool. Serum BDNF (sBDNF) levels were assessed by immunoassay.

RESULTS

In this study, we found that average MMSE score and sBDNF level of the subjects in arsenic-endemic areas were significantly (p < 0.001 for both) lower than those of the subjects in non-endemic area. Our analyses revealed that both MMSE scores and sBDNF levels were decreased with the increasing concentrations of arsenic in drinking water, hair, and nails in a dose-dependent fashion. In regression analyses, significant associations of arsenic exposure metrics with MMSE scores and sBDNF levels were observed even after adjustment for several variables. Intriguingly, MMSE scores showed a significantly positive correlation with sBDNF levels.

CONCLUSION

Our findings demonstrate that chronic exposure to arsenic dose-dependently decreases cognitive function in adults, with a concomitant reduction of sBDNF levels. A decreased BDNF level may be part of the biochemical basis of chronic arsenic exposure-related cognitive impairment.

Using Multistate Observational Studies to Determine Role of Hypertension and Diabetes as Risk Factors for Dementia

BACKGROUND

Evidence suggests that modifiable risk factors which can be targeted by prevention are vascular diseases, such as diabetes, midlife hypertension (HTN), midlife obesity, midlife cholesterol, mid- and late-life depression as well as lifestyle factors such as smoking, physical inactivity, and poor diet.

METHODS

A comprehensive search of the National Library of Medicine's PubMed database and Google Scholar was conducted. A combinations of medical subject headings and free text words that included search terms related to the exposure (e.g., prevalence, HTN, raised BP, high BP, diabetes, high blood sugar, DM, India, state), were combined with search terms related to the outcomes (e.g., prevalence, disease burden, estimate, dementia, India). The filters included were English for the language category and humans for the study category.

RESULTS

The PubMed search initially identified 269 references, and a total of 204 abstracts were screened by inclusion criteria. Full-text assessment of 136 articles on prevalence of dementia resulted in 20 relevant articles from which the different regions of the country were identified. Based on the search conducted according to the regions; 287abstracts of the prevalence of HTN and 577 on the prevalence of diabetes mellitus were screened. There were 43 full-text articles on the prevalence of HTN and diabetes from the regions where the prevalence of dementia was available. Of these potentially relevant articles were 14 in number.

CONCLUSION

Despite the uncertainty in the role, the data analysis, therefore, points to a role in the prevention of HTN and diabetes to prevent dementia.

Short test of mental status in the detection of mild cognitive impairment in India

CONTEXT

Mild cognitive impairment (MCI) is an under-diagnosed health problem in the community. Cognitive screening tools are widely used for MCI detection, but many of them lack sensitivity and specificity in MCI detection. On the basis of literature review, Short test of mental status (STMS) was selected for the present purpose.

AIMS

The present study purports to standardize STMS for using as a cognitive screening tool in MCI detection in the community-living elderly people in Kolkata.

MATERIALS AND METHODS

Data were collected from 102 community-living elderly people from the city of Kolkata using the purposive method of sampling. MCI was diagnosed using the Peterson's criteria of MCI as the gold standard. A semi-structured demographic proforma, clock-drawing test (CDT), and the Groningen Activity Restriction Scale (GARS) were used for the purpose. Finally, STMS was administered.

STATISTICAL ANALYSIS

Statistical computation was done using the SPSS 21. Descriptive statistics, receiver operating curve analysis, and binary logistic regression were used for statistical analysis of the data.

RESULTS AND CONCLUSION

STMS emerged as a sensitive and specific cognitive screening tool in the detection of MCI in the current cultural setting. It was also found to be more suited for the purpose than CDT. A score of 34.5 with a sensitivity of 97.5 and a specificity of 90.3% were selected for the optimum cutoff score for the detection of MCI in the present population. With a unit increase in STMS score, the odds of getting diagnosed with MCI were found to be reduced by 48.5%.

Association of vitamin B12 mediated hyperhomocysteinemia and methylenetetrafolate reductase (C677T) gene polymorphism with cognitive impairment: A population based study from North India

The present study attempts to understand the association of homocysteine, vitamin B12, folate, and MTHFR C677T gene polymorphism with cognitive impairment (CI) among 808 individuals of either sex (aged 30-70 years) from a largely vegetarian, mendelian population of North India. Biochemical and genetic analyses were done using standard protocols. Results indicate that 34.3% of the subjects had mild CI, 28.7% moderate CI and 0.2% were having severe CI. Hyperhomocysteinemia was found to be a significant risk factor for moderate/severe CI. Both CT genotype and T allele of MTHFR C677T gene polymorphism were found to pose significant decreased risk for CI.

Computer classes and games in virtual reality environment to reduce loneliness among students of an elderly reference center: Study protocol for a randomised cross-over design

INTRODUCTION

Physical and mental changes associated with aging commonly lead to a decrease in communication capacity, reducing social interactions and increasing loneliness. Computer classes for older adults make significant contributions to social and cognitive aspects of aging. Games in a virtual reality (VR) environment stimulate the practice of communicative and cognitive skills and might also bring benefits to older adults. Furthermore, it might help to initiate their contact to the modern technology. The purpose of this study protocol is to evaluate the effects of practicing VR games during computer classes on the level of loneliness of students of an elderly reference center.

METHODS AND ANALYSIS

This study will be a prospective longitudinal study with a randomised cross-over design, with subjects aged 50 years and older, of both genders, spontaneously enrolled in computer classes for beginners. Data collection will be done in 3 moments: moment 0 (T0) - at baseline; moment 1 (T1) - after 8 typical computer classes; and moment 2 (T2) - after 8 computer classes which include 15 minutes for practicing games in VR environment. A characterization questionnaire, the short version of the Short Social and Emotional Loneliness Scale for Adults (SELSA-S) and 3 games with VR (Random, MoviLetrando, and Reaction Time) will be used. For the intervention phase 4 other games will be used: Coincident Timing, Motor Skill Analyser, Labyrinth, and Fitts. The statistical analysis will compare the evolution in loneliness perception, performance, and reaction time during the practice of the games between the 3 moments of data collection. Performance and reaction time during the practice of the games will also be correlated to the loneliness perception.

ETHICS AND DISSEMINATION

The protocol is approved by the host institution's ethics committee under the number 52305215.3.0000.0082. Results will be disseminated via peer-reviewed journal articles and conferences. This clinical trial is registered at ClinicalTrials.gov identifier: NCT02798081.

Ideal Cardiovascular Health and Cognitive Aging in the Northern Manhattan Study

BACKGROUND

The American Heart Association defined target levels for 7 cardiovascular health (CVH) factors: smoking, body mass index, physical activity, diet, blood pressure, cholesterol, and glucose. We hypothesized that a greater number of American Heart Association ideal CVH metrics would be associated with less decline in cognitive performance in our multiethnic population.

METHODS AND RESULTS

A subsample from the population-based Northern Manhattan Study underwent repeated neuropsychological testing (mean interval 6±2 years). Domain-specific Z scores were derived by using factor analysis for the domains of Episodic Memory, Semantic Memory, Executive Function, and Processing Speed, based on initial performance and decline over time. Linear regression models were constructed to examine the relationship between the number of ideal CVH metrics at enrollment with later cognitive performance and decline, adjusting for sociodemographics and magnetic resonance imaging brain markers. Among 1033 participants (mean age at initial cognitive assessment 72±8 years, 39% male, 19% black, 16% white, 65% Hispanic; n=722 with repeat testing), 3% had 0 ideal factors, 15% had 1 factor, 33% had 2 factors, 30% had 3 factors, 14% had 4 factors, 4% had 5 factors, 1% had 6 factors, and 0% had 7 factors. An increasing number of ideal CVH factors was associated with better processing speed at initial assessment and less decline. The association was driven by nonsmoking and glucose. Among those with better cognitive performance at initial assessment, positive associations were observed between the number of ideal CVH factors and less decline in the domains of Executive Function and Episodic Memory.

CONCLUSIONS

The number of ideal CVH metrics was associated with less decline in the domains of Processing Speed and, to a lesser extent, of Executive Function and Episodic Memory. Ideal CVH promotion benefits brain health and cognitive aging.