Prevalence of cognitive impairment without dementia in the United States

Prediction of future dementia among patients with mild cognitive impairment (MCI) by integrating multimodal clinical data

Efficiently and objectively analyzing the complex, diverse multimodal data collected from patients at risk for dementia can be difficult in the clinical setting, contributing to high rates of underdiagnosis or misdiagnosis of this serious disorder. Patients with mild cognitive impairment (MCI) are especially at risk of developing dementia in the future. This study evaluated the ability of multi-modal machine learning (ML) methods, especially the Ensemble Integration (EI) framework, to predict future dementia development among patients with MCI. EI is a machine learning framework designed to leverage complementarity and consensus in multimodal data, which may not be adequately captured by methods used by prior dementia-related prediction studies. We tested EI's ability to predict future dementia development among MCI patients using multimodal clinical and imaging data, such as neuroanatomical measurements from structural magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, from The Alzheimer's Disease Prediction of Longitudinal Evolution (TADPOLE) challenge. For predicting future dementia development among MCI patients, on a held out test set, the EI-based model performed better (AUC = 0.81, F-measure = 0.68) than the more commonly used XGBoost (AUC = 0.68, F-measure = 0.57) and deep learning (AUC = 0.79, F-measure = 0.61) approaches. This EI-based model also suggested MRI-derived volumes of regions in the middle temporal gyrus, posterior cingulate gyrus and inferior lateral ventricle brain regions to be predictive of progression to dementia.

Using eZIS to Predict Progression from MCI to Dementia in Three Years

(1) Background: Mild cognitive impairment (MCI) due to Alzheimer's disease (AD) progresses to dementia at a higher annual rate, while other MCIs may remain stable or even improve over time. Discriminating progressive from non-progressive cases of MCI is crucial and challenging. (2) Methods: A retrospective study of individuals with MCI was conducted at a university hospital located in southern Taiwan. The researchers collected demographic data, comorbidities, the scores of cognitive tests, three easy Z-score imaging system (eZIS) indicators (severity, extent, and ratio), Fazekas scale scores, mesial temporal atrophy (MTA) scores, clinical outcomes including deterioration of Cognitive Abilities Screening Instrument, Mini-mental State Examination, Clinical Dementia Rating Sum of Box scores, and the conversion from MCI to dementia. Those who converted to dementia in three years and non-converters were compared by the three eZIS indicators to test the predictive utility, and the clinical outcomes were evaluated by regression and ROC curve analysis. (3) Results: The three eZIS indicators were significantly higher in the group of progressive MCI than in stable MCI. eZIS severity is positively correlated with a deterioration in the scores of the Cognitive Abilities Screening Instrument and Clinical Dementia Rating Sum of Box. eZIS severity is also positively correlated with conversion from MCI to dementia. The AUC for severity is 0.719, and the optimal cutoff value of severity for predicting conversion is 1.22. (4) Conclusions: During three years of follow-up, MCI individuals with greater eZIS severity were significantly associated with worse cognitive assessment scores and a higher conversion rate to dementia.

Importance of serum albumin in machine learning-based prediction of cognitive function in the elderly using a basic blood test

Introduction

In this study, we investigated the correlation between serum albumin levels and cognitive function, and examined the impact of including serum albumin values in the input layer on the prediction accuracy when forecasting cognitive function using deep learning and other machine learning models.

Methods

We analyzed the electronic health record data from Osaka Medical and Pharmaceutical University Hospital between 2014 and 2021. The study included patients who underwent cognitive function tests during this period; however, patients from whom blood test data was not obtained up to 30 days before the cognitive function tests and those with values due to measurement error in blood test results were excluded. The Mini-Mental State Examination (MMSE) was used as the cognitive function test, and albumin levels were examined as the explanatory variable. Furthermore, we estimated MMSE scores from blood test data using deep learning models (DLM), linear regression models, support vector machines (SVM), decision trees, random forests, extreme gradient boosting (XGBoost), and light gradient boosting machines (LightGBM).

Results

Out of 5,017 patients who underwent cognitive function tests, 3,663 patients from whom blood test data had not been obtained recently and two patients with values due to measurement error were excluded. The final study population included 1,352 patients, with 114 patients (8.4%) aged below 65 and 1,238 patients (91.6%) aged 65 and above. In patients aged 65 and above, the age and male sex showed significant associations with MMSE scores of less than 24, while albumin and potassium levels showed negative associations with MMSE scores of less than 24. Comparing MMSE estimation performance, in those aged below 65, the mean squared error (MSE) of DLM was improved with the inclusion of albumin. Similarly, the MSE improved when using SVM, random forest and XGBoost. In those aged 65 and above, the MSE improved in all models.

Discussion

Our study results indicated a positive correlation between serum albumin levels and cognitive function, suggesting a positive correlation between nutritional status and cognitive function in the elderly. Serum albumin levels were shown to be an important explanatory variable in the estimation of cognitive function for individuals aged 65 and above.

Overcoming Pandemic-Related Challenges in Recruitment and Screening: Strategies and Representation of Older Women With Cardiovascular Disease for a Multidomain Lifestyle Trial to Prevent Cognitive Decline

BACKGROUND

Recruiting participants with cardiovascular disease into research during the COVID-19 pandemic was challenging, particularly those at risk of health disparities.

OBJECTIVE

During the pandemic, 12 cohorts of older women with cardiovascular disease were recruited from cardiology clinics into a lifestyle intervention trial to prevent cognitive decline. Objectives were to ( a ) describe the results of modified recruitment/screening strategies to overcome pandemic-related challenges and ( b ) evaluate differences in age, race, and ethnicity between patients recruited/randomized, recruited/not randomized (entered recruitment but not randomized because of being ineligible or not interested), and not recruited (clinic patients who met preliminary criteria but did not enter recruitment).

METHODS

This was a cross-sectional descriptive analysis. In-person study strategies proposed before the COVID-19 pandemic were modified before study onset (September 2020). Women 65 years or older with cardiovascular disease were recruited from cardiology clinics by clinicians, posted flyers, and letters mailed to patients randomly selected from electronic health record data extractions. Patients were classified as recruited/randomized, recruited/not randomized, and not recruited.

RESULTS

Of 5719 patients potentially eligible, 1689 patients entered recruitment via referral (49.1%), posted flyers (0.5%), or mailed letters (50.3%), and 253 patients were successfully recruited/randomized. Recruited/randomized participants were, on average, 72.4 years old (range, 65-90 years old), non-Hispanic White (54.2%), non-Hispanic Black (38.3%), Hispanic/Latinx (1.6%), and other/not reported (5.1%). The recruited/randomized group was significantly younger with fewer patients of Hispanic/Latinx ethnicity compared with those not recruited.

CONCLUSIONS

During the pandemic, all recruitment/screening goals were met using modified strategies. Differences in sociodemographic representation indicate a need for tailored strategies.

Social Environment, Lifestyle, and Genetic Predisposition With Dementia Risk: A Long-Term Longitudinal Study Among Older Adults

BACKGROUND

The role of social environment, that is, the aggregate effect of social determinants of health (SDOHs), in determining dementia is unclear.

METHODS

We developed a novel polysocial risk score for dementia based on 19 SDOH among 5 199 participants in the Health and Retirement Study, United States, to measure the social environmental risk. We used a survival analysis approach to assess the association between social environment and dementia risk in 2006-2020. We further studied the interaction between social environment and lifestyles, and explored racial disparities.

RESULTS

The study participants (mean age = 73.4 years, SD = 8.3; 58.0% female; 11.6% African American) were followed up for an average of 6.2 years, and 1 089 participants developed dementia. Every 1-point increase in the polysocial risk score (ranging from 0 to 10) was associated with a 21.6% higher risk (adjusted hazard ratio [aHR] = 1.21, 95% confidence intervals [95% CI] = 1.15-1.26) of developing dementia, other things being equal. Among participants with high social environmental risk, regular exercise and moderate drinking were associated with a 43%-60% lower risk of developing dementia (p < .001). In addition, African Americans were 1.3 times (aHR = 2.28, 95% CI = 1.96-2.66) more likely to develop dementia than European Americans, other things being equal.

CONCLUSION

An adverse social environment is linked to higher dementia risk, but healthy lifestyles can partially offset the increased social environmental risk. The polysocial risk score can complement the existing risk tools to identify high-risk older populations, and guide the design of targeted social environmental interventions, particularly focusing on improving the companionship of the older people, to prevent dementia.

Hemodynamic Reactivity to Mental Stress and Cognitive Function in Coronary Artery Disease

OBJECTIVE

People with coronary artery disease (CAD) are at higher risk of cognitive impairment than those without CAD. Psychological stress is a risk factor for both conditions, and assessing the hemodynamic reactivity to mental stress could explain the link between stress and cognitive function.

METHODS

A total of 779 individuals with stable CAD from two prospective cohort studies were included. All individuals underwent acute mental stress testing, as well as conventional stress testing. Cognitive function was assessed both at baseline and at a 2-year follow-up. The rate-pressure product (RPP) was calculated as the mean systolic blood pressure times the mean heart rate at rest. RPP reactivity was defined as the maximum RPP during standardized mental stress test minus the RPP at rest.

RESULTS

After multivariable adjustment, every standard deviation decrease in RPP reactivity with mental stress was associated with slower completion of Trail-A and Trail-B in both cohorts (13% and 11% in cohort 1, and 15% and 16% in cohort 2, respectively; p for all <.01). After a 2-year follow-up period, every standard deviation decrease in RPP reactivity with mental stress was associated with a 8% and 9% slower completion of Trail-A and Trail-B, respectively ( p for all <.01). There was no significant association between RPP reactivity with conventional stress testing and any of the cognitive tests.

CONCLUSION

In the CAD population, a blunted hemodynamic response to mental stress is associated with slower visuomotor processing and worse executive function at baseline and with greater decline in these abilities over time.

The neuron-specific IIS/FOXO transcriptome in aged animals reveals regulatory mechanisms of cognitive aging

Cognitive decline is a significant health concern in our aging society. Here, we used the model organism C. elegans to investigate the impact of the IIS/FOXO pathway on age-related cognitive decline. The daf-2 Insulin/IGF-1 receptor mutant exhibits a significant extension of learning and memory span with age compared to wild-type worms, an effect that is dependent on the DAF-16 transcription factor. To identify possible mechanisms by which aging daf-2 mutants maintain learning and memory with age while wild-type worms lose neuronal function, we carried out neuron-specific transcriptomic analysis in aged animals. We observed downregulation of neuronal genes and upregulation of transcriptional regulation genes in aging wild-type neurons. By contrast, IIS/FOXO pathway mutants exhibit distinct neuronal transcriptomic alterations in response to cognitive aging, including upregulation of stress response genes and downregulation of specific insulin signaling genes. We tested the roles of significantly transcriptionally-changed genes in regulating cognitive functions, identifying novel regulators of learning and memory. In addition to other mechanistic insights, a comparison of the aged vs young daf-2 neuronal transcriptome revealed that a new set of potentially neuroprotective genes is upregulated; instead of simply mimicking a young state, daf-2 may enhance neuronal resilience to accumulation of harm and take a more active approach to combat aging. These findings suggest a potential mechanism for regulating cognitive function with age and offer insights into novel therapeutic targets for age-related cognitive decline.

Assessment of Cognitive Function in European Adults Aged 50+in Relation to Their Handgrip Strength and Physical Inactivity: The SHARE Study During 2019-2020

BACKGROUND

Cognitive function is crucial during aging. This study assessed the cognitive function of European adults aged 50 and over in relation to handgrip strength and physical inactivity. Study Design: This was a cross-sectional survey.

METHODS

Data were collected from 41,395 adults from 27 European countries participating in the Survey of Health, Ageing, and Retirement in Europe (SHARE) during 2019-2020. Cognitive function was assessed based on five tests, and cognitive impairment was defined using 3+tests. Handgrip strength and physical inactivity were also correlated through the analysis of covariance using a complex study design.

RESULTS

The majority of participants were female (56.6%), with a mean age of 70.9 years, and 22.6% presented multimorbidity. Furthermore, 51.1% had a normal cognitive function, while 13.3% had cognitive impairment (The estimated population was 21,944,722). Moreover, cognitive impairment was more prevalent in females than in males (14.4% vs. 12.0%, P<0.001) in patients with no years of education (P<0.001) and origin from southern European countries (P<0.001). Additionally, participants with cognitive impairment had lower mean handgrip strength compared to those with cognitive impairment in 1-2 criteria or with normal cognitive function (29.3 vs. 33.4 and 35.1 kg, respectively, P<0.001). Physically inactive participants had higher odds ratio (OR) of cognitive impairment than those engaging in moderate/vigorous physical activity, both in 1-2 tests (OR:1.73, 95% confidence interval (CI): 1.32-2.26) and in 3+tests (OR: 3.36, 95% CI: 2.57-4.40).

CONCLUSION

Cognitive impairment presented low prevalence and was associated with low levels of handgrip strength and physical inactivity. These specific factors may play a special role in early detection, diagnosis, and treatment or may slow down the progression of cognitive impairment.

Exploring the Acceptability and Feasibility of Remote Blood Pressure Measurements and Cognition Assessments Among Participants Recruited From a Safety-Net Emergency Department (Reach Out Cognition): Nonrandomized Mobile Health Trial

BACKGROUND

Hypertension is a prevalent cardiovascular risk factor disproportionately affecting Black Americans, who also experience a higher incidence of Alzheimer disease and Alzheimer disease-related dementias. Monitoring blood pressure (BP) and cognition may be important strategies in reducing these disparities.

OBJECTIVE

The objective of the Reach Out Cognition study was to explore the feasibility and acceptability of remote cognitive and BP assessments in a predominantly Black, low-income population.

METHODS

Reach Out was a randomized, controlled, mobile health-based clinical trial to reduce BP among patients with hypertension at an emergency department in a safety-net hospital (ie, a US hospital in which 25% of the patients are Medicaid recipients). Upon conclusion of Reach Out, participants were given the option of continuing into an extension phase, Reach Out Cognition, that included Bluetooth-enabled BP monitoring and digital cognitive assessments for 6 months. Digital cognitive assessments were text message-linked online surveys of the Self-Administered Gerocognitive Exam and Quality of Life in Neurological Disorders scale. BP assessments were measured with Bluetooth-enabled BP cuffs paired with an app and the data were manually sent to the research team. Outcomes were feasibility (ie, enrollment and 3- and 6-month completion of digital cognitive and BP assessments) and acceptability of assessments using a 4-item validated survey, ranging from 1 (not acceptable) to 5 (completely acceptable).

RESULTS

Of the 211 Reach Out participants, 107 (50.7%) consented and 71 (33.6%) completed enrollment in Reach Out Cognition. Participants had a mean age of 49.9 years; 70.4% were female and 57.8% identified as Black. Among the 71 participants, 51 (72%) completed cognitive assessments at 3 months and 34 (48%) completed these assessments at 6 months. BP assessments were completed by 37 (52%) and 20 (28%) of the 71 participants at 3 and 6 months, respectively. Participants were neutral on the acceptability of the digital cognitive assessments (mean 3.7) and Bluetooth self-measured BP (SMBP) monitoring (mean 3.9). Participants noted challenges syncing the BP cuff to the app, internet connection, and transmitting the data to the research team.

CONCLUSIONS

Enrollment and assessment completion were low, while acceptability was moderate. Technological advances will eliminate some of the Bluetooth SMBP barriers and offer new strategies for cognitive assessments. Subsequent studies could benefit from offering more comprehensive support to overcome Bluetooth-related hurdles, such as personalized training materials, video conferencing, or in-person research team support. Alternatively, strategies that do not require pairing with an app and passive transmission of data could be considered. Overall, further research is warranted to optimize participant engagement and overcome technological challenges.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03422718; https://clinicaltrials.gov/study/NCT03422718.

Spatiotemporal analysis of gene expression in the human dentate gyrus reveals age-associated changes in cellular maturation and neuroinflammation

The dentate gyrus of the hippocampus is important for many cognitive functions, including learning, memory, and mood. Here, we investigated age-associated changes in transcriptome-wide spatial gene expression in the human dentate gyrus across the lifespan. Genes associated with neurogenesis and the extracellular matrix were enriched in infants, while gene markers of inhibitory neurons and cell proliferation showed increases and decreases in post-infancy, respectively. While we did not find evidence for neural proliferation post-infancy, we did identify molecular signatures supporting protracted maturation of granule cells. We also identified a wide-spread hippocampal aging signature and an age-associated increase in genes related to neuroinflammation. Our findings suggest major changes to the putative neurogenic niche after infancy and identify molecular foci of brain aging in glial and neuropil enriched tissue.

Hybrid representation learning for cognitive diagnosis in late-life depression over 5 years with structural MRI

Late-life depression (LLD) is a highly prevalent mood disorder occurring in older adults and is frequently accompanied by cognitive impairment (CI). Studies have shown that LLD may increase the risk of Alzheimer's disease (AD). However, the heterogeneity of presentation of geriatric depression suggests that multiple biological mechanisms may underlie it. Current biological research on LLD progression incorporates machine learning that combines neuroimaging data with clinical observations. There are few studies on incident cognitive diagnostic outcomes in LLD based on structural MRI (sMRI). In this paper, we describe the development of a hybrid representation learning (HRL) framework for predicting cognitive diagnosis over 5 years based on T1-weighted sMRI data. Specifically, we first extract prediction-oriented MRI features via a deep neural network, and then integrate them with handcrafted MRI features via a Transformer encoder for cognitive diagnosis prediction. Two tasks are investigated in this work, including (1) identifying cognitively normal subjects with LLD and never-depressed older healthy subjects, and (2) identifying LLD subjects who developed CI (or even AD) and those who stayed cognitively normal over five years. We validate the proposed HRL on 294 subjects with T1-weighted MRIs from two clinically harmonized studies. Experimental results suggest that the HRL outperforms several classical machine learning and state-of-the-art deep learning methods in LLD identification and prediction tasks.

Epigenetic scores of blood-based proteins as biomarkers of general cognitive function and brain health

BACKGROUND

Epigenetic Scores (EpiScores) for blood protein levels have been associated with disease outcomes and measures of brain health, highlighting their potential usefulness as clinical biomarkers. They are typically derived via penalised regression, whereby a linear weighted sum of DNA methylation (DNAm) levels at CpG sites are predictive of protein levels. Here, we examine 84 previously published protein EpiScores as possible biomarkers of cross-sectional and longitudinal measures of general cognitive function and brain health, and incident dementia across three independent cohorts.

RESULTS

Using 84 protein EpiScores as candidate biomarkers, associations with general cognitive function (both cross-sectionally and longitudinally) were tested in three independent cohorts: Generation Scotland (GS), and the Lothian Birth Cohorts of 1921 and 1936 (LBC1921 and LBC1936, respectively). A meta-analysis of general cognitive functioning results in all three cohorts identified 18 EpiScore associations (absolute meta-analytic standardised estimates ranged from 0.03 to 0.14, median of 0.04, PFDR < 0.05). Several associations were also observed between EpiScores and global brain volumetric measures in the LBC1936. An EpiScore for the S100A9 protein (a known Alzheimer disease biomarker) was associated with general cognitive functioning (meta-analytic standardised beta: - 0.06, P = 1.3 × 10-9), and with time-to-dementia in GS (Hazard ratio 1.24, 95% confidence interval 1.08-1.44, P = 0.003), but not in LBC1936 (Hazard ratio 1.11, P = 0.32).

CONCLUSIONS

EpiScores might make a contribution to the risk profile of poor general cognitive function and global brain health, and risk of dementia, however these scores require replication in further studies.

Serum soluble alpha-klotho klotho and cognitive functioning in older adults aged 60 and 79: an analysis of cross-sectional data of the National Health and Nutrition Examination Survey 2011 to 2014

OBJECTIVES

Klotho, consisting of membrane klotho and soluble alpha-klotho, is found to be associated with better cognitive outcomes in small samples of the aged population. We aimed to examine the association of serum soluble alpha-klotho with cognitive functioning among older adults using a nationally representative sample of U.S. older adults.

METHOD

A total of 2,173 U.S. older adults aged 60-79 years in the National Health and Nutrition Examination Survey from 2011 to 2014 were included in this cross-sectional analysis. Serum soluble alpha-klotho was measured in the laboratory and analyzed with an ELISA kit. Cognitive function was measured using the Consortium to Establish a Registry for Alzheimer's Disease Word Learning subtest (CERAD-WL) immediate and delayed memory, the Animal fluency test (AFT), and the Digit Symbol Substitution Test (DSST). Test-specific and global cognition z-scores were calculated based on sample means and standard deviations. Multivariable linear regression models were applied to examine the association of quartiles and continuous value of serum soluble alpha-klotho with test-specific and global cognition z-scores. Subgroup analysis was conducted by sex. The following covariates were included in the analysis- age, sex, race/ethnicity, education, depressive symptoms, smoking status, body mass index (BMI), physical activity, stroke, prevalent coronary heart disease, total cholesterol, and systolic blood pressure. All the information was self-reported or obtained from health exams.

RESULTS

Serum soluble alpha-klotho level in the lowest quartile was associated with lower z-scores for DSST (beta [β] =-0.13, 95% confidence interval [CI]: -0.25, -0.01). For subgroup analysis, serum soluble alpha-klotho level in the lowest quartile was associated with lower z-scores for DSST (β=-0.16, 95% CI: -0.32, -0.003) and global cognition (β=-0.14, 95% CI: -0.28, -0.01) among female participants. No association was found between continuous serum soluble alpha-klotho and cognitive functioning among the participants.

CONCLUSIONS

Lower serum soluble alpha-klotho quartile was associated with poorer cognitive functioning among older women. Future studies are expected to examine the longitudinal association between klotho levels and cognitive outcomes.

Sex and race differences in the association of albumin with cognitive function in older adults

BACKGROUND

With the increasing aging population, dementia has become a significant socioeconomic burden. However, the effects of albumin on delayed recall (DR) impairment remain unclear, and there are limited reports on sex and race differences in this relationship. This study aimed to investigate the association between albumin levels and DR impairment in older adults.

METHODS

A total of 1507 normal cognitive function and 553 DR impairment from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 were included in this cross-sectional analysis. Participants aged 60 years and above were assessed using the Consortium to Establish a Registry for Alzheimer's Disease DR (CERAD-DR) test to evaluate cognitive function. Participants were categorized into DR impairment and normal cognitive function groups according to their CERAD-DR scores. Logistic regression analyses, generalized additive models, and fitted smoothing curves were utilized for data analysis.

RESULTS

After adjusting for potential confounders, a negative association was found between albumin levels and cognitive function (odds ratio [OR] = 0.60, 95% confidence interval [CI] 0.41-0.87). Subgroup analysis stratified by sex, race/ethnicity, and age revealed that the negative association remained significant in men (OR = 0.53, 95%CI 032-0.87), Blacks (OR = 0.35, 95%CI 0.17-0.74), and the age group of 60-70 years (OR = 0.48, 95%CI 0.28-0.81). However, no significant association was observed in women (OR = 0.72, 95%CI 0.41-1.28), whites (OR = 0.58, 95%CI 0.31-1.07), or Mexican Americans (OR = 1.11, 95%CI 0.35-3.46), as well as the age group of 71-80 years (OR = 0.62, 95%CI 0.37-1.03).

CONCLUSIONS

Our study suggests that elevated albumin levels are associated with a decreased incidence of cognitive function impairment, particularly in older men and Blacks. This finding indicates that maintaining high levels of albumin may be beneficial for cognitive function in older adults.

The relationship between cognitive impairment and fatty acids and carnitine in hemodialysis patients

BACKGROUND/AIM

The prevalence of cognitive impairment (CI) is high in hemodialysis patients. In this study, the relationship between CI and serum carnitine, plasma omega-3, omega-6 and omega-3/omega-6 fatty acid ratio was evaluated in hemodialysis patients.

MATERIALS AND METHODS

Sixty two patients [male: 40 (64.5%), mean age 51±13 years] were included in this cross-sectional study. Serum total and free-carnitine levels were determined by ELISA. Plasma omega-3 [eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)] and omega-6 [arachidonic acid (AA), dihomo gamma linoleic acid (DGLA)] levels were measured using LC-ESI-MS/MS. According to the Montreal Cognitive Assessment (MoCA) scores, ≤24 points were considered as CI. MoCA score ≤24 and >24 were determined as Group 1 and Group 2, respectively.

RESULTS

Group 1 had significantly higher AA+DGLA/EPA+DHA ratios and lower free-carnitine, DHA and EPA+DHA levels compared to Group 2 (P=0.008, P=0.040, P=0.032, P=0.032, respectively). Group 1 had a statistically lower education level (P<0.05). Negative correlation was found between MoCA scores and AA+DGLA/EPA+DHA ratios (rs=-0.284, P=0.026). Free-carnitine levels were positively correlated with EPA and EPA+DHA levels (rs=0.278, P=0.030 and rs=0.271, P=0.034, respectively), and negative correlated with AA+DGLA/EPA+DHA ratios (rs=-0.414, P=0.001). In multivariate logistic regression analysis, MoCA scores was associated with AA+DGLA/EPA+DHA ratio (P=0.009) and education level (P<0.001).

CONCLUSION

It was determined that high AA+DGLA/EPA+DHA ratio and low education level could be independent risk factors of the CI. It has been shown that free-carnitine level can have positive effects on plasma EPA+DHA and AA+DGLA distributions. Low omega-3 fatty acid levels may be associated with CI in hemodialysis patients, and low carnitine level may contribute partially to this process. In addition, cognitive education programs may have an effect on preventing CI in hemodialysis patients with low education levels.

Factor structure of the Harmonized Cognitive Assessment Protocol neuropsychological battery in the Health and Retirement Study

OBJECTIVE

The Harmonized Cognitive Assessment Protocol (HCAP) describes an assessment battery and a family of population-representative studies measuring neuropsychological performance. We describe the factorial structure of the HCAP battery in the US Health and Retirement Study (HRS).

METHOD

The HCAP battery was compiled from existing measures by a cross-disciplinary and international panel of researchers. The HCAP battery was used in the 2016 wave of the HRS. We used factor analysis methods to assess and refine a theoretically driven single and multiple domain factor structure for tests included in the HCAP battery among 3,347 participants with evaluable performance data.

RESULTS

For the eight domains of cognitive functioning identified (orientation, memory [immediate, delayed, and recognition], set shifting, attention/speed, language/fluency, and visuospatial), all single factor models fit reasonably well, although four of these domains had either 2 or 3 indicators where fit must be perfect and is not informative. Multidimensional models suggested the eight-domain model was overly complex. A five-domain model (orientation, memory delayed and recognition, executive functioning, language/fluency, visuospatial) was identified as a reasonable model for summarizing performance in this sample (standardized root mean square residual = 0.05, root mean square error of approximation = 0.05, confirmatory fit index = 0.94).

CONCLUSIONS

The HCAP battery conforms adequately to a multidimensional structure of neuropsychological performance. The derived measurement models can be used to operationalize notions of neurocognitive impairment, and as a starting point for prioritizing pre-statistical harmonization and evaluating configural invariance in cross-national research.

A comparison of the diagnostic accuracy of the Mini-Cog and AD8 in identifying cognitive impairment in a geriatric health screening population in China

The present study aimed to evaluate and compare the discriminative abilities of the Mini-Cog and AD8 tests in detecting cognitive impairment in a Chinese health screening population. 160 geriatric participants were enrolled at an academic medical center . The Mini-Cog, AD8, and Mini-Mental State Examination (MMSE) were used to assess the possibility of cognitive impairment. Logistic regression and receiver operator characteristic curve analyses were performed to evaluate the discriminative abilities of the tests. The prevalence of cognitive impairment was 41.25%. Logistic regression modeling showed that the Mini-Cog (odds ratio (OR) = 0.34, 95% confidence interval (CI): 0.25-0.46) and MMSE (OR = 0.58, 95%CI: 0.49-0.69) predicted cognitive impairment with 79.4% and 80.6% correct classification, respectively. While the AD8 (OR = 1.56, 95% CI: 1.32-1.85) predicted cognitive impairment with 72.5% correct classification. The areas under the receiver operating characteristic curves of the Mini-Cog, AD8 and MMSE for detecting cognitive impairment were 0.79 (95% CI: 0.72-0.85), 0.66 (95% CI: 0.58-0.73) and 0.80 (95% CI: 0.73-0.86). Both sensitivity and specificity of the Mini-Cog were superior to those of the AD8 (sensitivity 78.79% vs. 56.06%; specificity 79.79% vs. 75.53%). Cognitive screening is crucial to maintain the quality of life of older adults. Compared with the AD8, the Mini-Cog test is a more effective tool for screening cognitive impairment in older adults.

Clusterization of Behavioral and Psychological Symptoms of Dementia as Assessed by Neuropsychiatric Inventory: A Case Against the Use of Principal Component Analysis

Background

The term Behavioral and Psychological Symptoms of Dementia (BPSD) covers a group of phenomenologically and medically distinct symptoms that rarely occur in isolation. Their therapy represents a major unmet medical need across dementias of different types, including Alzheimer's disease. Understanding of the symptom occurrence and their clusterization can inform clinical drug development and use of existing and future BPSD treatments.

Objective

The primary aim of the present study was to investigate the ability of a commonly used principal component analysis to identify BPSD patterns as assessed by Neuropsychiatric Inventory (NPI).

Methods

NPI scores from the Aging, Demographics, and Memory Study (ADAMS) were used to characterize reported occurrence of individual symptoms and their combinations. Based on this information, we have designed and conducted a simulation experiment to compare Principal Component analysis (PCA) and zero-inflated PCA (ZI PCA) by their ability to reveal true symptom associations.

Results

Exploratory analysis of the ADAMS database revealed overlapping multivariate distributions of NPI symptom scores. Simulation experiments have indicated that PCA and ZI PCA cannot handle data with multiple overlapping patterns. Although the principal component analysis approach is commonly applied to NPI scores, it is at risk to reveal BPSD clusters that are a statistical phenomenon rather than symptom associations occurring in clinical practice.

Conclusions

We recommend the thorough characterization of multivariate distributions before subjecting any dataset to Principal Component Analysis.

Sleep structure assessed by objective measurement in patients with mild cognitive impairment: A meta-analysis

OBJECTIVES

A meta-analysis was used to explore the characteristic changes in objective sleep structure of patients with mild cognitive impairment (MCI) compared with cognitively healthy older adults.

MATERIALS AND METHODS

PubMed, EMBAS, Cochrane Library, Scopus, and Web of Science were searched until November 2023. A literature quality evaluation was performed according to the Newcastle-Ottawa Scale, and a meta-analysis was performed by RevMan 5.3 software.

RESULTS

Fifteen studies with 771 participants were finally included. Compared with normal control groups, patients with MCI had a decreased total sleep time by 34.44 min, reduction in sleep efficiency by 7.96 %, increased waking after sleep onset by 19.61 min, and increased sleep latency by 6.97 min. Ten included studies showed that the patients with MCI had increased N1 sleep by 2.72 % and decreased N3 sleep by 0.78 %; however, there was no significant difference between the MCI and control groups in percentage of N2 sleep. Moreover, Twelve included studies reported the MCI groups had shorter REM sleep of 2.69 %.

CONCLUSION

Our results provide evidence of abnormal sleep architecture in patients with MCI. As a "plastic state," abnormal sleep architecture may be a promising therapeutic target for slowing cognitive decline and dementia prevention.

Homocysteine and nutritional biomarkers in cognitive impairment

Cognitive impairment is a progressive disorder that affects the ageing population. With the increase in the mean age of our population, it is becoming a public health problem. Homocysteinemia has been implicated in cognitive impairment. Whilst it is modulated by vitamins B12 and folate, it acts through MMPs 2 and 9. To assesses the relationship of cognitive impairment with homocysteine, B12, folate and MMPs 2 and 9, so as to detect cases of mild cognitive impairment which are potentially reversible, blood samples were drawn from 73 enrolled subjects, with and without cognitive impairment on basis of Montreal cognitive assessment (MoCA) score < 25 or ≥ 25, respectively. Homocysteine, B12, folate and MMPs2 and 9 were estimated. Correlation between MoCA score and these parameters was elucidated. After adjusting for age and gender, homocysteine was the only significant independent predictor of MoCA score. Cut-off of homocysteine for prediction of MoCA < 25 was derived at 13.5 µmol/L(PPV = 59.6%; NPV = 79.2%). The equation derived for calculation of MoCA score from homocysteine is: MoCA score = 32.893 + [(- 0.223)(homocysteine in μmol/L)]. Homocysteine > 13.5 μmol/L predicts low MoCA (< 25) with 84.8% sensitivity and 50% specificity. Hence, patients with an Hcy > 13.5 μmol/L should be administered B12 and folate to reduce homocysteine, a modifiable risk factor of cognitive decline. Also, a novel equation for calculating MoCA score from homocysteine has been derived. Using this derived equation to calculate MoCA score, it may be possible to identify asymptomatic subjects with early cognitive impairment.

Current Challenges in the Diagnosis of Progressive Neurocognitive Disorders: A Critical Review of the Literature and Recommendations for Primary and Secondary Care

Screening for early symptoms of cognitive impairment enables timely interventions for patients and their families. Despite the advances in dementia diagnosis, the current nosography of neurocognitive disorders (NCDs) seems to overlook some clinical manifestations and predictors that could contribute to understanding the conversion from an asymptomatic stage to a very mild one, eventually leading to obvious disease. The present review examines different diagnostic approaches in view of neurophysiological and neuropsychological evidence of NCD progression, which may be subdivided into: (1) preclinical stage; (2) transitional stage; (3) prodromal or mild stage; (4) major NCD. The absence of univocal criteria and the adoption of ambiguous or narrow labels might complicate the diagnostic process. In particular, it should be noted that: (1) only neuropathological hallmarks characterize preclinical NCD; (2) transitional NCD must be assessed through proactive neuropsychological protocols; (3) prodromal/mild NCDs are based on cognitive functional indicators; (4) major NCD requires well-established tools to evaluate its severity stage; (5) insight should be accounted for by both patient and informants. Therefore, the examination of evolving epidemiological and clinical features occurring at each NCD stage may orient primary and secondary care, allowing for more targeted prevention, diagnosis, and/or treatment of both cognitive and functional impairment.

Cognitive impairment indicator for the neuropsychological test batteries in the Canadian Longitudinal Study on Aging: definition and evidence for validity

BACKGROUND

Prevalence of overall cognitive impairment based on each participant's performance across a neuropsychological battery is challenging; consequently, we define and validate a dichotomous cognitive impairment/no cognitive indicator (CII) using a neuropsychological battery administered in a population-based study. This CII approximates the clinical practice of interpretation across a neuropsychological battery and can be applied to any neuropsychological dataset.

METHODS

Using data from participants aged 45-85 in the Canadian Longitudinal Study on Aging receiving a telephone-administered neuropsychological battery (Tracking, N = 21,241) or a longer in-person battery (Comprehensive, N = 30,097), impairment was determined for each neuropsychological test based on comparison with normative data. We adjusted for the joint probability of abnormally low scores on multiple neuropsychological tests using baserates of low scores demonstrated in the normative samples and created a dichotomous CII (i.e., cognitive impairment vs no cognitive impairment). Convergent and discriminant validity of the CII were assessed with logistic regression analyses.

RESULTS

Using the CII, the prevalence of cognitive impairment was 4.3% in the Tracking and 5.0% in the Comprehensive cohorts. The CII demonstrated strong convergent and discriminant validity.

CONCLUSIONS

The approach for the CII is a feasible method to identify participants who demonstrate cognitive impairment on a battery of tests. These methods can be applied in other epidemiological studies that use neuropsychological batteries.

Prevalence of Alzheimer's disease dementia in the 50 US states and 3142 counties: A population estimate using the 2020 bridged-race postcensal from the National Center for Health Statistics

INTRODUCTION

This study estimates the prevalence and number of people living with Alzheimer's disease (AD) dementia in 50 US states and 3142 counties.

METHODS

We used cognitive data from the Chicago Health and Aging Project, a population-based study, and combined it with the National Center for Health Statistics 2020 bridged-race population estimates to determine the prevalence of AD in adults ≥65 years.

RESULTS

A higher prevalence of AD was estimated in the east and southeastern regions of the United States, with the highest in Maryland (12.9%), New York (12.7%), and Mississippi (12.5%). US states with the highest number of people with AD were California, Florida, and Texas. Among larger counties, those with the highest prevalence of AD were Miami-Dade County in Florida, Baltimore city in Maryland, and Bronx County in New York.

DISCUSSION

The state- and county-specific estimates could help public health officials develop region-specific strategies for caring for people with AD.

Effect of Continuous Ingestion of Bifidobacteria and Dietary Fiber on Improvement in Cognitive Function: A Randomized, Double-Blind, Placebo-Controlled Trial

Bifidobacterium animalis subsp. lactis GCL2505 has been shown to have some positive effects on health, including improved defecation frequency and reduced visceral fat. These effects are thought to be due to GCL2505's unique ability to reach the intestine in a viable form and proliferate after a single intake. This leads to an increased number of intestinal bifidobacteria. This randomized, double-blind, placebo-controlled, parallel-group study was conducted to confirm that intake of GCL2505 and inulin (a prebiotic) improve cognitive function (n = 80). Participants consumed test drinks containing 1 × 1010 colony-forming units of GCL2505 per 100 g and 2.0 g of inulin per 100 g for 12 weeks. The change in cognitive function assessment scores was set as the primary endpoint. There were significant improvements in scores in the neurocognitive index domain, which is an assessment of overall cognitive function, in addition to overall attention, cognitive flexibility, and executive function domains. The intervention significantly increased the number of fecal bifidobacteria and affected the levels of several inflammatory markers. These results suggest that intake of GCL2505 and inulin improves cognitive function by improving the intestinal environment and alleviating inflammation.

Machine learning-based quantification for disease uncertainty increases the statistical power of genetic association studies

MOTIVATION

Allowance for increasingly large samples is a key to identify the association of genetic variants with Alzheimer's disease (AD) in genome-wide association studies (GWAS). Accordingly, we aimed to develop a method that incorporates patients with mild cognitive impairment and unknown cognitive status in GWAS using a machine learning-based AD prediction model.

RESULTS

Simulation analyses showed that weighting imputed phenotypes method increased the statistical power compared to ordinary logistic regression using only AD cases and controls. Applied to real-world data, the penalized logistic method had the highest AUC (0.96) for AD prediction and weighting imputed phenotypes method performed well in terms of power. We identified an association (P<5.0×10-8) of AD with several variants in the APOE region and rs143625563 in LMX1A. Our method, which allows the inclusion of individuals with mild cognitive impairment, improves the statistical power of GWAS for AD. We discovered a novel association with LMX1A.

AVAILABILITY AND IMPLEMENTATION

Simulation codes can be accessed at https://github.com/Junkkkk/wGEE_GWAS.

Vitamin B12 supplementation improves cognitive function in middle aged and elderly patients with cognitive impairment

Introduction

Objectives: to determine the effects of vitamin B12 supplementation on neuropsychological function and disease progression in middle aged and elderly patients with cognitive impairment. Methods: this was a prospective case-control study. From May 2020 to May 2021, 307 participants clinically diagnosed with cognitive impairment in the Department of Neurology of the First Affiliated Hospital of Chongqing Medical University were enrolled. A total of 115 patients were included in this study. Meanwhile, 115 participants with cognitive impairment were randomly assigned in equal proportions to two groups: vitamin B12 treatment group (n = 58, vitamin B12 500 mg/d intramuscularly for seven days, followed by cobamamide 0.25 mg/d and methylcobalamin 0.50 mg/d) and the control group (n = 57). Demographic characteristics and blood biochemical variables were obtained from all participants. Cognitive performance was measured using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Cognitive performance was measured at baseline and after six months. Results: the vitamin B12 supplementation treatment patients who presented with cognitive impairment showed significant improvement, especially in attention, calculation (p < 0.01) and visual-constructional ability (p < 0.05), in their neuropsychological function compared to their matched group. Conclusion: vitamin B12 supplementation may improve frontal function in patients with cognitive decline. Vitamin B12 levels should be investigated in all patients with cognitive impairment.

Acute Myocardial Infarction and Risk of Cognitive Impairment and Dementia: A Review

Cognitive impairment (CI) shares common cardiovascular risk factors with acute myocardial infarction (AMI), and is increasingly prevalent in our ageing population. Whilst AMI is associated with increased rates of CI, CI remains underreported and infrequently identified in patients with AMI. In this review, we discuss the evidence surrounding AMI and its links to dementia and CI, including pathophysiology, risk factors, management and interventions. Vascular dysregulation plays a major role in CI, with atherosclerosis, platelet activation, microinfarcts and perivascular inflammation resulting in neurovascular unit dysfunction, disordered homeostasis and a dysfunctional neurohormonal response. This subsequently affects perfusion pressure, resulting in enlarged periventricular spaces and hippocampal sclerosis. The increased platelet activation seen in coronary artery disease (CAD) can also result in inflammation and amyloid-β protein deposition which is associated with Alzheimer's Dementia. Post-AMI, reduced blood pressure and reduced left ventricular ejection fraction can cause chronic cerebral hypoperfusion, cerebral infarction and failure of normal circulatory autoregulatory mechanisms. Patients who undergo coronary revascularization (percutaneous coronary intervention or bypass surgery) are at increased risk for post-procedure cognitive impairment, though whether this is related to the intervention itself or underlying cardiovascular risk factors is debated. Mortality rates are higher in dementia patients with AMI, and post-AMI CI is more prevalent in the elderly and in patients with post-AMI heart failure. Medical management (antiplatelet, statin, renin-angiotensin system inhibitors, cardiac rehabilitation) can reduce the risk of post-AMI CI; however, beta-blockers may be associated with functional decline in patients with existing CI. The early identification of those with dementia or CI who present with AMI is important, as subsequent tailoring of management strategies can potentially improve outcomes as well as guide prognosis.

Developing and validating a nomogram for cognitive impairment in the older people based on the NHANES

Objective

To use the United States National Health and Nutrition Examination Study (NHANES) to develop and validate a risk-prediction nomogram for cognitive impairment in people aged over 60 years.

Methods

A total of 2,802 participants (aged ≥ 60 years) from NHANES were analyzed. The least absolute shrinkage and selection operator (LASSO) regression model and multivariable logistic regression analysis were used for variable selection and model development. ROC-AUC, calibration curve, and decision curve analysis (DCA) were used to evaluate the nomogram's performance.

Results

The nomogram included five predictors, namely sex, moderate activity, taste problem, age, and education. It demonstrated satisfying discrimination with a AUC of 0.744 (95% confidence interval, 0.696-0.791). The nomogram was well-calibrated according to the calibration curve. The DCA demonstrated that the nomogram was clinically useful.

Conclusion

The risk-prediction nomogram for cognitive impairment in people aged over 60 years was effective. All predictors included in this nomogram can be easily accessed from its' user.

Design and baseline characteristics of the Cognitive and Aerobic Resilience for the Brain (CARB) study

BACKGROUND

Treatments that delay progression of cognitive impairment in older adults are of great public health significance. This manuscript outlines the protocol, recruitment, baseline characteristics, and retention for a randomized controlled trial of cognitive and aerobic physical training to improve cognition in individuals with subjective cognitive dysfunction, the "Cognitive and Aerobic Resilience for the Brain" (CARB) study.

METHODS

Community-dwelling, older adults with self-reported memory loss were randomly assigned to receive either computer-based cognitive training, aerobic physical training, combined cognitive and physical training, or education control. Treatment was delivered 2- to 3-times per week in 45- to 90-min sessions for 12 weeks by trained facilitators videoconferencing into subject's home. Outcome assessments of were taken at the baseline, immediately following training, and 3-months after training.

RESULTS

191 subjects were randomized into the trial (mean age, 75.5 years; 68% female; 20% non-white; mean education, 15.1 years; 30% with 1+ APOE e4 allele). The sample was generally obese, hypertensive, and many were diabetic, while cognition, self-reported mood, and activities of daily living were in the normal range. There was excellent retention throughout the trial. Interventions were completed at high rates, participants found the treatments acceptable and enjoyable, and outcome assessments were completed at high rates.

CONCLUSIONS

This study was designed to determine the feasibility of recruiting, intervening, and documenting response to treatment in a population at risk for progressive cognitive decline. Older adults with self-reported memory loss were enrolled in high numbers and were well engaged with the intervention and outcome assessments.

Rates of Undiagnosed Cognitive Impairment and Performance on the Montreal Cognitive Assessment Among Older Adults in Primary Care

BACKGROUND

The number of adults in the USA with cognitive impairment is increasing; however, few studies report prevalence rates of undiagnosed cognitive impairment among older adults in primary care.

OBJECTIVE

To determine the prevalence of undiagnosed cognitive impairment among adults ages 55 years and older in primary care settings and provide normative data for the Montreal Cognitive Assessment in this context.

DESIGN

Single interview, observational study.

PARTICIPANTS

English-speaking adults ages 55 years and older without diagnoses of cognitive impairment recruited from primary care practices in New York City, NY, and Chicago, IL (n = 872).

MAIN MEASURES

Montreal Cognitive Assessment (MoCA). Undiagnosed cognitive impairment was defined by age and education adjusted z-scores more than 1.0 and 1.5 standard deviations below published norms, corresponding to mild or moderate to severe cognitive impairment, respectively.

KEY RESULTS

The mean age was 66.8 (8.0) years, 44.7% were male, 32.9% were Black or African-American, and 29.1% were Latinx. Undiagnosed cognitive impairment was identified in 20.8% of subjects (mild impairment, 10.5%; moderate-severe impairment, 10.3%). Impairment at any level of severity was associated in bivariate analyses with several patient characteristics, most notably for race and ethnicity (White, non-Latinx, 6.9% vs. Black, non-Latinx, 26.8%, Latinx, 28.2%, other race, 21.9%; p < 0.0001), place of birth (US 17.5% vs. non-US 30.7%, p < 0.0001), depression (33.1% vs. no depression, 18.1%; p < 0.0001), and impairment in activities of daily living (≥ 1 ADL impairment, 34.0% vs. no ADL impairment, 18.2%; p < 0.0001).

CONCLUSIONS

Undiagnosed cognitive impairment is common among urban dwelling older adults attending primary care practices, and was associated with several patient characteristics, including non-White race and ethnicity and depression. Normative data for the MoCA from this study may serve as a useful resource for studies of similar patient populations.

Validation of Self-Reported Cancer Diagnoses by Respondent Cognitive Status in the U.S. Health and Retirement Study

BACKGROUND

Cancer and dementia are becoming increasingly common co-occurring conditions among older adults. Yet, the influence of participant cognitive status on the validity of self-reported data among older adults in population-based cohorts is unknown. We thus compared self-reported cancer diagnoses in the U.S. Health and Retirement Study (HRS) against claims from linked Medicare records to ascertain the validity of self-reported diagnoses by participant cognitive and proxy interview status.

METHODS

Using data from HRS participants aged ≥67 who had at least 90% continuous enrollment in fee-for-service Medicare, we examined the validity of self-reported first incident cancer diagnoses from biennial HRS interviews against diagnostic claim records in linked Medicare data (reference standard) for interviews from 2000 to 2016. Cognitive status was classified as normal, cognitive impairment no dementia (CIND), or dementia using the Langa-Weir method. We calculated the sensitivity, specificity, and κ for cancer diagnosis.

RESULTS

Of the 8 280 included participants, 23.6% had cognitive impairment without dementia (CIND) or dementia, and 10.7% had a proxy respondent due to an impairment. Self-reports of first incident cancer diagnoses for participants with normal cognition had 70.2% sensitivity and 99.8% specificity (κ = 0.79). Sensitivity declined substantially with cognitive impairment and proxy response (56.7% for CIND, 53.0% for dementia, 60.0% for proxy respondents), indicating poor validity for study participants with CIND, dementia, or a proxy respondent.

CONCLUSIONS

Self-reported cancer diagnoses in the U.S. HRS have poor validity for participants with cognitive impairment, dementia, or a proxy respondent. Population-based cancer research among older adults will be strengthened with linkage to Medicare claims.

Diabetes, Edentulism, and Cognitive Decline: A 12-Year Prospective Analysis

Diabetes mellitus (DM) is a recognized risk factor for dementia, and increasing evidence shows that tooth loss is associated with cognitive impairment and dementia. However, the effect of the co-occurrence of DM and edentulism on cognitive decline is understudied. This 12-y cohort study aimed to assess the effect of the co-occurrence of DM and edentulism on cognitive decline and examine whether the effect differs by age group. Data were drawn from the 2006 to 2018 Health and Retirement Study. The study sample included 5,440 older adults aged 65 to 74 y, 3,300 aged 75 to 84 y, and 1,208 aged 85 y or older. Linear mixed-effect regression was employed to model the rates of cognitive decline stratified by age cohorts. Compared with their counterparts with neither DM nor edentulism at baseline, older adults aged 65 to 74 y (β = -1.12; 95% confidence interval [CI], -1.56 to -0.65; P < 0.001) and those aged 75 to 84 y with both conditions (β = -1.35; 95% CI, -2.09 to -0.61; P < 0.001) had a worse cognitive function. For the rate of cognitive decline, compared to those with neither condition from the same age cohort, older adults aged 65 to 74 y with both conditions declined at a higher rate (β = -0.15; 95% CI, -0.20 to -0.10; P < 0.001). Having DM alone led to an accelerated cognitive decline in older adults aged 65 to 74 y (β = -0.09; 95% CI, -0.13 to -0.05; P < 0.001); having edentulism alone led to an accelerated decline in older adults aged 65 to 74 y (β = -0.13; 95% CI, -0.17 to -0.08; P < 0.001) and older adults aged 75 to 84 (β = -0.10; 95% CI, -0.17 to -0.03; P < 0.01). Our study finds the co-occurrence of DM and edentulism led to a worse cognitive function and a faster cognitive decline in older adults aged 65 to 74 y.

Community-Led, Cross-Sector Partnership of Housing and Health Care to Promote Aging in Place (Unite Health Project): Protocol for a Prospective Observational Study

BACKGROUND

For many older Americans, aging in place is their preferred living arrangement. Minoritized and socioeconomically disadvantaged older adults are up to 3 times more likely to experience disability than other groups, which increases their likelihood of being unable to age in place. Bold ideas to facilitate aging in place, particularly among vulnerable populations, are needed. One such idea is the Unite care model, a community-initiated, academic-supported, cross-sector initiative that combines 2 sectors: housing and health care. The Unite care model colocates a federally qualified health center clinic on an older adult affordable housing campus in Flint, Michigan.

OBJECTIVE

There are two aims to this study. Aim 1 is to evaluate the implementation of the Unite care model in terms of acceptability, adoption, and penetration. Aim 2 is to determine which older adults use the care model and whether the care model promotes aging in place through risk factor reduction and improvement in the physical and social environment.

METHODS

We will assess the care model using a concurrent, exploratory mixed methods design. For aim 1, acceptability will be assessed through semistructured interviews with key stakeholder groups; adoption and penetration will be assessed using housing and health care records. For aim 2, residents residing in the Unite clinic building will participate in structured outcome assessments at 6 and 12 months. Risk factor reduction will be measured by change in systolic blood pressure from baseline to 12 months and change in the physical and social environment (item counts) will also be assessed from baseline to 12 months.

RESULTS

Data collection for aim 1 began in July 2021 and is anticipated to end in April 2023. Data collection for aim 2 began in June 2021 and concluded in November 2022. Data analysis for aim 1 is anticipated to begin in the summer of 2023 and analysis for aim 2 will begin in the spring of 2023.

CONCLUSIONS

If successful, the Unite care model could serve as a new care model to promote aging in place among older adults living in poverty and older Black Americans. The results of this proposal will inform whether larger scale testing of this new model of care is warranted.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/47855.

Assessing and managing frailty in emergency laparotomy: a WSES position paper

Many countries are facing an aging population. As people live longer, surgeons face the prospect of operating on increasingly older patients. Traditional teaching is that with older age, these patients face an increased risk of mortality and morbidity, even to a level deemed too prohibitive for surgery. However, this is not always true. An active 90-year-old patient can be much fitter than an overweight, sedentary 65-year-old patient with comorbidities. Recent literature shows that frailty-an age-related cumulative decline in multiple physiological systems, is therefore a better predictor of mortality and morbidity than chronological age alone. Despite recognition of frailty as an important tool in identifying vulnerable surgical patients, many surgeons still shun objective tools. The aim of this position paper was to perform a review of the existing literature and to provide recommendations on emergency laparotomy and in frail patients. This position paper was reviewed by an international expert panel composed of 37 experts who were asked to critically revise the manuscript and position statements. The position paper was conducted according to the WSES methodology. We shall present the derived statements upon which a consensus was reached, specifying the quality of the supporting evidence and suggesting future research directions.

Development and validation of an interpretable machine learning model-Predicting mild cognitive impairment in a high-risk stroke population

Background

Mild cognitive impairment (MCI) is considered a preclinical stage of Alzheimer's disease (AD). People with MCI have a higher risk of developing dementia than healthy people. As one of the risk factors for MCI, stroke has been actively treated and intervened. Therefore, selecting the high-risk population of stroke as the research object and discovering the risk factors of MCI as early as possible can prevent the occurrence of MCI more effectively.

Methods

The Boruta algorithm was used to screen variables, and eight machine learning models were established and evaluated. The best performing models were used to assess variable importance and build an online risk calculator. Shapley additive explanation is used to explain the model.

Results

A total of 199 patients were included in the study, 99 of whom were male. Transient ischemic attack (TIA), homocysteine, education, hematocrit (HCT), diabetes, hemoglobin, red blood cells (RBC), hypertension, prothrombin time (PT) were selected by Boruta algorithm. Logistic regression (AUC = 0.8595) was the best model for predicting MCI in high-risk groups of stroke, followed by elastic network (ENET) (AUC = 0.8312), multilayer perceptron (MLP) (AUC = 0.7908), extreme gradient boosting (XGBoost) (AUC = 0.7691), and support vector machine (SVM) (AUC = 0.7527), random forest (RF) (AUC = 0.7451), K-nearest neighbors (KNN) (AUC = 0.7380), decision tree (DT) (AUC = 0.6972). The importance of variables suggests that TIA, diabetes, education, and hypertension are the top four variables of importance.

Conclusion

Transient ischemic attack (TIA), diabetes, education, and hypertension are the most important risk factors for MCI in high-risk groups of stroke, and early intervention should be performed to reduce the occurrence of MCI.

Influence of mild cognitive impairment on patient and care partner decision-making for acute ischemic stroke

GOALS

Evidence suggests that patients with mild cognitive impairment (MCI) receive fewer treatments for acute ischemic stroke and other cardiovascular diseases than patients with normal cognition. Little is known about how patient and care partner preferences for ischemic stroke treatment differ between the patient population with MCI and the population with normal cognition. This study aimed to understand how patient MCI diagnosis influences patient and care partner decision-making for acute ischemic stroke treatments.

METHODS

Multi-center qualitative study using in-person semi-structured interviews with 20 MCI and normal cognition patient-care partner dyads using a standard guide. The present study reports results on patient and care partner preferences for a clinical vignette patient to receive three non-invasive treatments (intravenous tissue plasminogen activator, inpatient rehabilitation, and secondary preventive medications) and two invasive treatments (feeding tube and carotid endarterectomy) after acute ischemic stroke. We used qualitative content analysis to identify themes.

FINDINGS

We identified three major themes: (1) Patients with MCI desired non-invasive treatments after stroke, similar to patients with normal cognition and for similar reasons; (2) Patients with MCI expressed different preferences than patients with normal cognition for two invasive treatments after stroke: carotid endarterectomy and feeding tube placement; and (3) Patients with MCI expressed more skepticism of the stroke treatment options and less decisiveness in decision-making than patients with normal cognition.

CONCLUSIONS

These results suggest that patient MCI diagnosis may contribute to differences in patient and care partner preferences for invasive treatments after stroke, but not for non-invasive treatments.

Predicting the Risk of Alzheimer's Disease and Related Dementia in Patients with Mild Cognitive Impairment Using a Semi-Competing Risk Approach

Alzheimer's disease (AD) and AD-related dementias (AD/ADRD) are a group of progressive neurodegenerative diseases. The progression of AD can be conceptualized as a continuum in which patients progress from normal cognition to preclinical AD (i.e., no symptoms but biological changes in the brain) to mild cognitive impairment (MCI) due to AD (i.e., mild symptoms but not interfere with daily activities), followed by increasing severity of dementia due to AD. Early detection and prediction models for the transition of MCI to AD/ADRD are needed, and efforts have been made to build predictions of MCI conversion to AD/ADRD. However, most existing studies developing such prediction models did not consider the competing risks of death, which may result in biased risk estimates. In this study, we aim to develop a prediction model for AD/ADRD among patients with MCI considering the competing risks of death using a semi-competing risk approach.

Effects of adenosine A2A receptors on cognitive function in health and disease

Adenosine A2A receptors have been studied extensively in the context of motor function and movement disorders such as Parkinson's disease. In addition to these roles, A2A receptors have also been increasingly implicated in cognitive function and cognitive impairments in diverse conditions, including Alzheimer's disease, schizophrenia, acute brain injury, and stress. We review the roles of A2A receptors in cognitive processes in health and disease, focusing primarily on the effects of reducing or enhancing A2A expression levels or activities in animal models. Studies reveal that A2A receptors in neurons and astrocytes modulate multiple aspects of cognitive function, including memory and motivation. Converging evidence also indicates that A2A receptor levels and activities are aberrantly increased in aging, acute brain injury, and chronic disorders, and these increases contribute to neurocognitive impairments. Therapeutically targeting A2A receptors with selective modulators may alleviate cognitive deficits in diverse neurological and neuropsychiatric conditions. Further research on the exact neural mechanisms of these effects as well as the efficacy of selective A2A modulators on cognitive alterations in humans are important areas for future investigation.

Predictive blood biomarkers and brain changes associated with age-related cognitive decline

Growing evidence supports the use of plasma levels of tau phosphorylated at threonine 181, amyloid-β, neurofilament light and glial fibrillary acidic protein as promising biomarkers for Alzheimer's disease. While these blood biomarkers are promising for distinguishing people with Alzheimer's disease from healthy controls, their predictive validity for age-related cognitive decline without dementia remains unclear. Further, while tau phosphorylated at threonine 181 is a promising biomarker, the distribution of this phospho-epitope of tau in the brain is unknown. Here, we tested whether plasma levels of tau phosphorylated at threonine 181, amyloid-β, neurofilament light and fibrillary acidic protein predict cognitive decline between ages 72 and 82 in 195 participants in the Lothian birth cohorts 1936 study of cognitive ageing. We further examined post-mortem brain samples from temporal cortex to determine the distribution of tau phosphorylated at threonine 181 in the brain. Several forms of tau phosphorylated at threonine 181 have been shown to contribute to synapse degeneration in Alzheimer's disease, which correlates closely with cognitive decline in this form of dementia, but to date, there have not been investigations of whether tau phosphorylated at threonine 181 is found in synapses in Alzheimer's disease or healthy ageing brain. It was also previously unclear whether tau phosphorylated at threonine 181 accumulated in dystrophic neurites around plaques, which could contribute to tau leakage to the periphery due to impaired membrane integrity in dystrophies. Brain homogenate and biochemically enriched synaptic fractions were examined with western blot to examine tau phosphorylated at threonine 181 levels between groups (n = 10-12 per group), and synaptic and astrocytic localization of tau phosphorylated at threonine 181 were examined using array tomography (n = 6-15 per group), and localization of tau phosphorylated at threonine 181 in plaque-associated dystrophic neurites with associated gliosis were examined with standard immunofluorescence (n = 8-9 per group). Elevated baseline plasma tau phosphorylated at threonine 181, neurofilament light and fibrillary acidic protein predicted steeper general cognitive decline during ageing. Further, increasing tau phosphorylated at threonine 181 over time predicted general cognitive decline in females only. Change in plasma tau phosphorylated at threonine 181 remained a significant predictor of g factor decline when taking into account Alzheimer's disease polygenic risk score, indicating that the increase of blood tau phosphorylated at threonine 181 in this cohort was not only due to incipient Alzheimer's disease. Tau phosphorylated at threonine 181 was observed in synapses and astrocytes in both healthy ageing and Alzheimer's disease brain. We observed that a significantly higher proportion of synapses contain tau phosphorylated at threonine 181 in Alzheimer's disease relative to aged controls. Aged controls with pre-morbid lifetime cognitive resilience had significantly more tau phosphorylated at threonine 181 in fibrillary acidic protein-positive astrocytes than those with pre-morbid lifetime cognitive decline. Further, tau phosphorylated at threonine 181 was found in dystrophic neurites around plaques and in some neurofibrillary tangles. The presence of tau phosphorylated at threonine 181 in plaque-associated dystrophies may be a source of leakage of tau out of neurons that eventually enters the blood. Together, these data indicate that plasma tau phosphorylated at threonine 181, neurofilament light and fibrillary acidic protein may be useful biomarkers of age-related cognitive decline, and that efficient clearance of tau phosphorylated at threonine 181 by astrocytes may promote cognitive resilience.

Nativity differences in the relationship between handgrip strength and cognitive impairment in older Mexican Americans over 20 years of follow-up

PURPOSE

To examine nativity differences in the relationship between handgrip strength (HGS) and cognitive impairment among Mexican Americans aged ≥ 65 years with normal or high cognitive function at baseline over a 20-year period.

METHODS

Prospective cohort study of 2,155 non-institutionalized Mexican Americans aged ≥ 65 years from the Hispanic Established Population for the Epidemiological Study of the Elderly) who scored ≥ 21 in the Mini Mental State Examination (MMSE) at baseline. Measures included socio-demographics, body mass index, medical conditions, depressive symptoms, physical function, disability, HGS quartiles (sex-adjusted), and MMSE. We used generalized estimating equation models to estimate the odds ratio (OR) and 95% Confidence Interval (CI) of cognitive impairment (MMSE < 21) as a function of HGS quartile by nativity and adjusted for covariates.

RESULTS

US-born and foreign-born participants in the 4th quartile (highest) of HGS at baseline had lower odds of cognitive impairment over time compared with those in the 1st (lowest) HGS quartile (OR=0.95, 95% CI=0.90-0.99 and OR=0.93, 95% CI=0.89-0.98, respectively), after controlling for all covariates. When we analyzed HGS quartiles as time-varying, we found that US-born participants in the 3rd and 4th HGS quartile had 25% and 30% lower odds of cognitive impairment, respectively, while foreign-born participants in the 3rd and 4th HGS quartile had 27% and 49% lower odds of cognitive impairment over time, respectively, after controlling for all covariates.

CONCLUSION

Foreign-born older Mexican Americans who performed high in HGS experienced 7% lower odds of cognitive impairment over time compared with US-born older Mexican Americans.

Feasibility of an online consensus approach for the diagnosis of cognitive impairment and dementia in rural South Africa

INTRODUCTION

We describe the development and feasibility of using an online consensus approach for diagnosing cognitive impairment and dementia in rural South Africa.

METHODS

Cognitive assessments, clinical evaluations, and informant interviews from Cognition and Dementia in the Health and Aging in Africa Longitudinal Study (HAALSI Dementia) were reviewed by an expert panel using a web-based platform to assign a diagnosis of cognitively normal, mild cognitive impairment (MCI), or dementia.

RESULTS

Six hundred thirty-five participants were assigned a final diagnostic category, with 298 requiring adjudication conference calls. Overall agreement between each rater's independent diagnosis and final diagnosis (via the portal or consensus conference) was 78.3%. A moderate level of agreement between raters' individual ratings and the final diagnostic outcomes was observed (average κ coefficient = 0.50).

DISCUSSION

Findings show initial feasibility in using an online consensus approach for the diagnosis of cognitive impairment and dementia in remote, rural, and low-resource settings.

A non-pharmacological multidomain intervention of dual-task exercise and social activity affects the cognitive function in community-dwelling older adults with mild to moderate cognitive decline: A randomized controlled trial

The present study aimed to determine the impact of a 10-month multidomain program using dual-task exercise and social activity conducted at a community-based facility on improved cognitive function in older adults with mild to moderate cognitive decline. The participants included 280 community-dwelling older adults (age 71–91 years) with mild to moderate cognitive decline. The intervention group exercised for 90 min/day, once a week. Their routine included aerobic exercise and dual-task training which cognitive tasks were performed in combination with exercise. The control group attended health education classes thrice. Before and after the intervention, we measured their cognitive function, physical function, daily conversation, and physical activity. The mean adherence rate of the intervention class was 83.0%. According to a repeated-measures multivariate analysis of covariance in an intent-to-treat analysis, logical memory and 6-min walking distance demonstrated a significant time and group interaction effect. Regarding daily physical activities, we observed significant differences in the daily step count and moderate-to-vigorous physical activity in the intervention group. Our non-pharmacological multidomain intervention resulted in a modest improvement in the cognitive or physical function and building health behavior. It may be a helpful program with a potential role in preventing dementia.

Clinical Trial Registration: http://clinicaltrials.gov Identifier ID: UMIN000013097.

Mediating role of depressive symptoms on the relationship between sleep duration and cognitive function

Although some studies have shown the association between sleep duration and cognitive impairment is positive, the mechanism explaining how sleep duration is linked to cognition remains poor understood. The current study aims to explore it among Chinese population. A cross-sectional study of 12,589 participants aged 45 or over was conducted, cognition was assessed by three measures to capture mental intactness, episodic memory, and visuospatial abilities. The Center for Epidemiologic Studies Depression Scale 10 (CES-D10) was administered during the face-to-face survey to assess depressive status. Sleep duration was reported by the participants themselves. Partial correlation and linear regression were used to explore the association between sleep duration, cognition, and depression. The Bootstrap methods PROCESS program was used to detect the mediation effect of depression. Sleep duration was positively correlated with cognition and negatively with depression (p < 0.01). The CES-D10 score (r = - 0.13, p < 0.01) was negatively correlated with cognitive function. Linear regression analysis showed sleep duration was positively associated with cognition (p = 0.001). When depressive symptoms were considered, the association between sleep duration and cognition lost significance (p = 0.468). Depressive symptoms have mediated the relationship between sleep duration and cognitive function. The findings revealed that the relationship between sleep duration and cognition is mainly explained by depressive symptoms and may provide new ideas for interventions for cognitive dysfunction.

Characteristics of the cognitive function transition and influencing factors among Chinese older people: An 8-year longitudinal study

BACKGROUND

Cognitive impairment among older people is an important public health problem in developing countries. Therefore, it is necessary to identify the subtypes of cognitive function among older people in China, and explore the transformation patterns and influencing factors.

METHODS

Longitudinal data from the China Health and Retirement Longitudinal Study (CHARLS) were used, and included 2140 women and 2049 men aged over 60 years. Latent profile and latent transition analysis (LPA&LTA) were used to identify subgroups and transitions between the profiles over time. Influencing factors were identified by multinomial logistic regression analysis.

RESULTS

According to the LPA model, three subgroups of cognitive function were identified: Cognitive Impairment, Mild Cognitive Impairment (MCI) and Normal Cognitive Function. Concurrently, >50 % of participants were likely to progress to MCI after seven years, whereas participants with cognitive impairment had a probability of 54.2 % of transitioning to a better cognitive profile. Older adults are less likely to experience cognitive improvement, higher levels of education affect changes in cognition, and having depression are at a lower risk of cognitive decline.

LIMITATIONS

Due to the incompleteness of the cognitive assessment and the large time span, there was a certain bias in the classification and analysis of latent cognitive profiles.

CONCLUSION

This study identified three latent profiles among Chinese older people and showed the stability and heterogeneity. It demonstrated the effects of higher age or levels of education, and depression on changes in cognitive function in older people.

Barriers to Using Legally Authorized Representatives in Clinical Research with Older Adults

Background

Older adults are at increased risk of cognitive impairments including Alzheimer's disease dementia. Legally authorized representatives (LARs) can provide informed consent when a participant is no longer able to, but little is known about barriers to incorporating them in research.

Objective

Explore reasons for not asking and documenting participant decisions to appoint LARs among researchers conducting clinical intervention trials studying older adults or individuals with cognitive impairments.

Methods

Mixed method design consisting of a survey (N = 1,284) and qualitative interviews (N = 40) regarding barriers to incorporating LARs. Participants were principal investigators and clinical research coordinators.

Results

37% (N = 469) had not asked and documented participant decisions about appointing LARs in the prior year. They had significantly lower confidence in resources available to incorporate LARs and lower positive attitudes compared to their counterparts who had done so. The majority (83%) had no trials studying individuals with cognitive impairments and reported LARs were not applicable. A minority (17%) had at least one trial studying individuals with cognitive impairments and reported being unaware of LARs. Qualitative findings indicate discomfort broaching a sensitive topic especially with individuals who are not yet impaired.

Conclusion

Resources and education to increase awareness and knowledge of LARs are needed. Researchers studying older adults should, at minimum, have the knowledge and resources to incorporate LARs when necessary. Stigma and discomfort discussing LARs will need to be overcome, as early proactive discussions before a participant loses decisional capacity could enhance participant autonomy and facilitate recruitment and retention of older adults to research.

Cognitive Trajectories and Associated Biomarkers in Patients with Mild Cognitive Impairment

BACKGROUND

To diagnose mild cognitive impairment (MCI) patients at risk of progression to dementia is clinically important but challenging.

OBJECTIVE

We classified MCI patients based on cognitive trajectories and compared biomarkers among groups.

METHODS

This study analyzed amnestic MCI patients with at least three Clinical Dementia Rating (CDR) scores available over a minimum of 36 months from the Alzheimer's Disease Neuroimaging Initiative database. Patients were classified based on their progression using trajectory modeling with the CDR-sum of box scores. We compared clinical and neuroimaging biomarkers across groups.

RESULTS

Of 569 eligible MCI patients (age 72.7±7.4 years, women n = 223), three trajectory groups were identified: stable (58.2%), slow decliners (24.6%), and fast decliners (17.2%). In the fifth year after diagnosis, the CDR-sum of box scores increased by 1.2, 5.4, and 11.8 points for the stable, slow, and fast decliners, respectively. Biomarkers associated with cognitive decline were amyloid-β 42, total tau, and phosphorylated tau protein in cerebrospinal fluid, hippocampal volume, cortical metabolism, and amount of cortical and subcortical amyloid deposits. Cortical metabolism and the amount of amyloid deposits were associated with the rate of cognitive decline.

CONCLUSION

Data-driven trajectory analysis provides new insights into the various cognitive trajectories of MCI. Baseline brain metabolism, and the amount of cortical and subcortical amyloid burden can provide additional information on the rate of cognitive decline.

Associations of lifestyle with physical, hearing, visual, and mental functional impairments among older adults: Findings from two prospective cohort studies

OBJECTIVE

To examine the associations between lifestyle habits and functional impairments among older adults.

METHODS

The study includes 20,545 women and 14,374 men aged 70 years or older at the time of the function assessment. Participants were from two prospective cohort studies: the Shanghai Women's Health Study (SWHS, enrollment from 1996 to 2000) and the Shanghai Men's Health Study (SMHS, enrollment from 2002 to 2006). Lifestyle information was collected at study enrollment and a healthy lifestyle score (HLS) was derived. Functional impairment information was collected at the follow-up survey conducted in 2012-2017. Logistic regression analyses were applied to estimate the associations of HLS with functional impairments.

RESULTS

The average age at lifestyle and functional impairment assessment was 62.3 (range: 49.9-70.9) and 77.7 (range: 70.0-89.4) for women and 67.5 (range: 55.1-74.9) and 77.4 (range: 70.0-88.6) for men. After a median follow-up of 14.4 years, we found that the HLS was inversely associated with overall severe functional impairment: odds ratio (95% confidence interval), 0.78(0.71-0.86) and individual severe functional impairment: 0.67(0.62-0.73) for independent walking, 0.85(0.77-0.94) for hearing/vision, 0.79(0.70-0.88) for memory, and 0.74(0.67-0.82) for decision-making impairment, comparing the highest with the lowest HLS categories. Such associations were similar among individuals with/without cardiometabolic diseases at baseline. The associations between each lifestyle factor and functional impairments differed.

CONCLUSION

A healthy lifestyle was associated with reduced odds of physical and mental impairment among older Chinese adults, emphasizing the importance of promoting and maintaining a healthy lifestyle to prevent or postpone age-related functional impairments.

The impact of study factors in the association of periodontal disease and cognitive disorders: systematic review and meta-analysis

AIM

The aim was to assess study factors that impact the association of cognitive disorders in people with periodontal disease (PD).

METHOD

Medline, EMBASE and Cochrane databases were searched until February 2022 using keywords and MeSH: (periodon* OR tooth loss OR missing teeth) AND (dementia OR Alzheimer's Disease OR cognitive*). Observational studies reporting prevalence or risk of cognitive decline, dementia or Alzheimer's disease (AD) in people with PD compared with healthy controls were included. Meta-analysis quantified the prevalence and risk (relative risk[RR]) of cognitive decline, dementia/AD, respectively. Meta-regression/subgroup analysis explored the impact of study factors including PD severity and classification type, and gender.

RESULTS

Overall, 39 studies were eligible for meta-analysis: 13 cross-sectional and 26 longitudinal studies. PD demonstrated increased risks of cognitive disorders (cognitive decline-RR = 1.33, 95% CI = 1.13-1.55; dementia/AD-RR = 1.22, 95% CI = 1.14-1.31). Risk of cognitive decline increased with PD severity (moderate-[RR] = 1.14, 95% confidence interval [CI] = 1.07-1.22; severe-RR = 1.25, 95% CI = 1.18-1.32). For every 10% population increase in females, the risk of cognitive decline increased by 34% (RR = 1.34, 95% CI = 1.16-1.55). Self-reported PD showed a lower risk of cognitive disorders compared with clinical classification (cognitive decline-RR = 0.77, 95% CI = 0.65-0.91; dementia/AD-RR = 0.86, 95% CI = 0.77-0.96).

CONCLUSION

The prevalence and risk estimates of cognitive disorders in association with PD can be influenced by gender, the disease classification of PD and its severity. Further homologous evidence taking these study factors into consideration is needed to form robust conclusions.