Risk Factors Affecting Cognitive Impairment of the Elderly Aged 65 and Over: A Cross-Sectional Study

Prevalence of Dementia and Cognitive Impairment in East Africa Region: A Scoping Review of Population-Based Studies and Call for Further Research

Background

Population-based research on the prevalence and determinants of dementia, Alzheimer's disease, and cognitive impairment is scarce in East Africa.

Objective

To provide an overview of community- and population-based studies among older adults on the prevalence of dementia and cognitive impairment in East Africa, and identify research gaps.

Methods

We carried out a literature search using three electronic databases (PubMed, Scopus, Google Scholar) using pertinent search terms.

Results

After screening 445 publications, we identified four publications on the population-based prevalence of dementia, and three on cognitive impairment. Prevalence rates varied from 6- 23% for dementia, and 7- 44% for cognitive impairment, among participants aged≥50-70 years. Old age and a lower education level were risk factors for dementia and cognitive impairment. Physical inactivity, lack of a ventilated kitchen, and history of central nervous system infections and chronic headache were associated with increased odds of dementia. Female sex, depression, having no spouse, increased lifetime alcohol consumption, low income, rural residence, and low family support were associated with increased odds of cognitive impairment. Potential misclassification and non-standardized data collection methods are research gaps that should be addressed in future studies.

Conclusions

Establishing collaborative networks and partnering with international research institutions may enhance the capacity for conducting population-based studies on dementia and cognitive impairment in East Africa. Longitudinal studies may provide valuable insights on incidence, as well as potential risk and protective factors of dementia and cognitive impairment, and may inform the development of targeted interventions including preventive strategies in the region.

Cerebrovascular dysregulation and postoperative cognitive alterations after carotid endarterectomy

There are controversial data about the effect of carotid endarterectomy regarding postoperative cognitive function. Our aim was to analyze the effect of cerebral tissue saturation monitored by near-infrared spectroscopy (NIRS) on cognitive function. Perioperative data of 103 asymptomatic patients undergoing elective carotid surgery under general anesthesia were analyzed. Preoperatively and 3 months after the operation, MMSE (Mini Mental State Examination) and MoCA (Montreal Cognitive Assessment) tests were conducted. For cerebral monitoring, NIRS was used, and the lowest rSO2 value and the degree of desaturation were calculated. Cognitive changes were defined as one standard deviation change from the preoperative test scores, defined as postoperative neurocognitive decline (PNCD) and cognitive improvement (POCI). PNCD was found in 37 patients (35.92%), and POCI was found in 18 patients (17.47%). Female gender, patients with diabetes, and the degree of desaturation were independently associated with PNCD. The degree of desaturation during the cross-clamp period negatively correlated with the change in the MoCA scores (R =  - 0.707, p = 0.001). The 15.5% desaturation ratio had 86.5% sensitivity and 78.8% specificity for discrimination. For POCI, a desaturation of less than 12.65% had 72.2% sensitivity and 67.1% specificity. POCI was associated with lower preoperative MOCA scores and a lower degree of desaturation. We found a significant relation between the change of postoperative cognitive function proven by the MoCA test and cerebral tissue saturation during the clamping period in patients undergoing carotid endarterectomy.

Cognitive Impairment and Its Associated Determinants Among the Elderly Population of Telangana, India: An Analytical Prevalence Study

INTRODUCTION

Dementia is an insidious cognitive disorder featuring a decline in cognition that is not well explained by the physiology of aging. Dementia includes a group of disorders that are distinguished by a gradual loss of both cognition and the capability to execute day-to-day functions.

MATERIALS AND METHODS

We conducted a cross-sectional study among 384 elderly participants in areas surrounding the All India Institute of Medical Sciences, Bibinagar, Telangana, India. Those with more than 65 years of age were included in the study, and those suffering from serious illnesses were excluded. The Montreal Cognitive Assessment (MOCA) scale, the University of California and Los Angeles (UCLA) Loneliness Scale, and the Patient Health Questionnaire (PHQ-9) were used to assess cognitive status, loneliness, and depression, respectively, among the study participants. Logistic regression was performed to identify factors associated with cognitive impairment (CI), depression, and loneliness.

RESULTS

The average MOCA score of the study participants was 14.9 ± 6.9, with 28.6% of the participants exhibiting severe CI. Nearly half of the participants (49.2%) experienced moderate to high degrees of loneliness, and 39.3% experienced moderate to severe depression. Important factors found to be associated with severe CI were illiteracy (adjusted odds ratio (AOR): 2.85, 95% CI: 1.35-4.45), urban residence (AOR: 0.18, 95% CI: 0.04-0.81), living with a spouse (AOR: 0.23, 95% CI: 0.11-0.78), not consuming alcohol (AOR: 0.35, 95% CI: 0.14-0.87), and depression (AOR: 4.49, 95% CI: 1.37-14.67).

CONCLUSION

CI is a serious public health problem in India. With the increasing proportion of the elderly population in the near future, CI levels will increase, especially in countries like India. Timely interventions such as early identification through community-based screening, the inclusion of a geriatric health component in primary health care, and proper counseling will help address this problem at a grassroots level.

Effects of Multimodal Exercise With Augmented Reality on Cognition in Community-Dwelling Older Adults

OBJECTIVES

This study aims to investigate the effects of an exercise intervention using multimodal exercise with augmented reality and multimodal exercise-only on cognitive function in older adults living in a community dwelling.

DESIGN

Quasi-experimental research study.

SETTING AND PARTICIPANTS

In this control study, 78 participants were divided into 2 experimental groups (with sessions 3 times a week for 12 weeks) and a control group (CG).

METHODS

EG1 participated in a multimodal exercise-only intervention program, EG2 participated in a multimodal exercise program with augmented reality exergames, and CG continued its usual activities. Participants were assessed at baseline and postintervention after 12 weeks.

RESULTS

Comparison between baseline and postintervention at 12 weeks showed significant improvements in executive functions, verbal fluency, choice reaction time, and dual task in EG1, whereas there were improvements in general cognition, executive functions, verbal fluency, discrimination reaction time, and depression in EG2 (P ≤ .05). The clinical effect sizes of the interventions were large for overall cognition, executive functions, and reaction time on single- and dual-task reaction time in EG1 and for overall cognition, executive functions, and verbal fluency in EG2.

CONCLUSION AND IMPLICATIONS

The intervention programs showed significant improvements in several cognitive domains. The multimodal exercise-only showed improvements in more variables than the multimodal exercise with augmented reality, but the augmented reality group showed greater changes between baseline and postintervention.

Association between intensity of physical activity and cognitive function in hypertensive patients: a case-control study

Previous studies have shown that a higher intensity of physical activity (PA) is associated with a lower risk of cognitive impairment (CI), whereas hypertension is associated with higher CI. However, there are few studies on the association between PA intensity and cognitive function in hypertensive patients. This study investigated the association between PA intensity and cognitive function in hypertensive patients. A total of 2035 hypertensive patients were included in this study, including 407 hypertensive patients with CI and 1628 hypertensive patients with normal cognitive function matched 1:4 by age and sex. The International Physical Activity Questionnaire-Long Form and the Mini-mental State Examination were used to evaluate PA intensity, total metabolic equivalents, and cognitive function in patients with hypertension. Multivariate logistic regression was used to analyze the correlation between PA intensity and CI in hypertensive patients. The Spearman correlation coefficient was used to analyze the correlation between PA intensity and the total score of each component of the MMSE and the correlation between PA total metabolic equivalents and cardiac structure in hypertensive patients. After adjusting for all confounding factors, PA intensity was negatively associated with CI in hypertensive patients (OR = 0.608, 95% CI: 0.447-0.776, P < 0.001), and this association was also observed in hypertensive patients with education level of primary school and below and junior high school and above (OR = 0.732, 95% CI: 0.539-0.995, P = 0.047; OR = 0.412, 95% CI: 0.272-0.626, P < 0.001). The intensity of PA in hypertensive patients was positively correlated with orientation (r = 0.125, P < 0.001), memory (r = 0.052, P = 0.020), attention and numeracy (r = 0.151, P < 0.001), recall ability (r = 0.110, P < 0.001), and language ability (r = 0.144, P < 0.001). PA total metabolic equivalents in hypertensive patients were negatively correlated with RVEDD and LAD (r = - 0.048, P = 0.030; r = - 0.051, P = 0.020) and uncorrelated with LVEDD (r = 0.026, P = 0.233). Higher PA intensity reduced the incidence of CI in hypertensive patients. Therefore, hypertensive patients were advised to moderate their PA according to their circumstances.

The associations between peripheral inflammatory and lipid parameters, white matter hyperintensity, and cognitive function in patients with non-disabling ischemic cerebrovascular events

BACKGROUND

The global prevalence of VCI has increased steadily in recent years, but diagnostic biomarkers for VCI in patients with non-disabling ischemic cerebrovascular incidents (NICE) remain indefinite. The primary objective of this research was to investigate the relationship between peripheral serological markers, white matter damage, and cognitive function in individuals with NICE.

METHODS

We collected clinical data, demographic information, and medical history from 257 patients with NICE. Using the MoCA upon admission, patients were categorized into either normal cognitive function (NCF) or VCI groups. Furthermore, they were classified as having mild white matter hyperintensity (mWMH) or severe WMH based on Fazekas scores. We then compared the levels of serological markers between the cognitive function groups and the WMH groups.

RESULTS

Among 257 patients with NICE, 165 were male and 92 were female. Lymphocyte count (OR = 0.448, P < 0.001) and LDL-C/HDL-C (OR = 0.725, P = 0.028) were protective factors for cognitive function in patients with NICE. The sWMH group had a higher age and inflammation markers but a lower MoCA score, and lymphocyte count than the mWMH group. In the mWMH group, lymphocyte count (AUC = 0.765, P < 0.001) and LDL-C/HDL-C (AUC = 0.740, P < 0.001) had an acceptable diagnostic value for the diagnosis of VCI. In the sWMH group, no significant differences were found in serological markers between the NCF and VCI groups.

CONCLUSION

Lymphocyte count, LDL-C/HDL-C were independent protective factors for cognitive function in patients with NICE; they can be used as potential biological markers to distinguish VCI in patients with NICE and are applicable to subgroups of patients with mWMH.

Association between serum omega-3 PUFAs levels and cognitive impairment in never medically treated first-episode patients with geriatric depression: A cross-sectional study

BACKGROUND

Geriatric depression increases the public health burden and health care costs, reduces quality of life. Studies have shown the association between ω-3 PUFAs levels and inflammatory markers levels and depression, but few have explored the relationship between omega-3 PUFAs, inflammatory markers, and cognitive function in geriatric depression. This study aimed to compare the differences in ω-3 PUFAs levels and inflammatory markers between geriatric depression with cognitive impairment (CI) and those without CI.

METHODS

A total of three hundred and five elderly patients were recruited. In addition to collecting basic information, their blood specimens were collected to detect serum EPA, DHA, AA, TC, LDL-C, IL-6, TNF-α, and hs-CRP levels. The Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA), and The Montreal cognitive assessment (MoCA) were used to assess their depression, anxiety, and cognitive function, respectively.

RESULTS

Compared to those without CI, geriatric depression patients with CI had higher serum TC, LDL-C levels, lower EPA, DHA, and AA levels, and more elevated IL-6, TNF-α, and hs-CRP levels (all P < 0.05). Further linear regression analysis showed that EPA, DHA, and TNF-α, hs-CRP levels were significantly associated with the occurrence and the severity of CI.

LIMITATIONS

No causal relationship could be drawn due to the cross-sectional design.

CONCLUSIONS

Omega-3 PUFAs and inflammatory factors levels may predict CI in elderly patients with MDD in the future. Our findings suggest that ω-3 PUFAs (EPA and DHA) and inflammatory factors (TNF-α and CRP) may predict the occurrence and the severity of CI among elderly MDD patients.

Prevalence and Associations of Cognitive Impairment in Adult Patients with Moyamoya Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Cognitive impairment, and in the long term Alzheimer's disease, vascular, or mixed dementia, are potential complications of moyamoya disease (MMD), of which the prevalence and associations are not well established.

OBJECTIVE

We performed a systematic review and meta-analysis to investigate the prevalence of cognitive impairment in adult patients with MMD as well as its clinical and demographic correlates.

METHODS

We performed a systematic search of four electronic databases: PubMed (MEDLINE), EMBASE, Scopus, and Cochrane Library, profiling studies from inception until 7 May 2023. Clinical data consisting of population characteristics, comorbidities, cognitive assessment tools used, and prevalence of cognitive impairment was extracted.

RESULTS

Seventeen studies were included in the meta-analysis, with a total study population of 1,190 patients. All studies assessed cognition, and the overall prevalence of cognitive impairment in MMD patients was 54.59%. A subgroup analysis identified that the prevalence of executive dysfunction in MMD patients was 31.55%. We performed a meta-regression analysis which identified that cognitive impairment was not associated with age, education level, or a history of ischemic or hemorrhagic stroke.

CONCLUSIONS

A substantial proportion of MMD patients have cognitive impairment, and cognitive impairment was found to have no association with a history of stroke. Further research is necessary to investigate the longitudinal relationship of MMD and cognitive impairment, and the impact of bypass surgery on cognitive impairment.

"I guess you can interpret it in a number of ways like kind of a milder or the mildest form of dementia?": Multi-stakeholder perceptions of cognitive impairment

INTRODUCTION

Mild cognitive impairment (MCI) has a high prevalence and is a risk factor for dementia. Furthering understanding of MCI has been identified as a public health priority. This research aimed to explore views about the causes of cognitive impairment and identify associations between cognitive impairment, dementia, and normative ageing.

METHOD

Semi-structured qualitative interviews were conducted with 22 participants with different stakeholder perspectives on the area of MCI in England, and analysed thematically.

RESULTS

Our analysis focuses on two main themes: 1) causes of cognitive impairment, and 2) ageing, dementia, and dying. Most participants viewed cognitive impairment as a transitional state between normative ageing and dementia. Participants expressed their fear of cognitive impairment and dementia, and made clear links between cognitive impairment and dying. Participants also showed an awareness of the links between lifestyle factors and cognitive health. However, linkage between lifestyle and cognition was discussed only when explicitly asked, suggesting that this was not especially salient for participants when considering the causes and risk factors for cognitive impairment.

CONCLUSION

The results of this study highlight key areas for future public health initiatives, such as a focus on the multitude of benefits offered by adopting a healthy diet and physical exercise in reducing risk of cognitive impairment.

Association between depression and quality of life in older adults with type 2 diabetes: A moderated mediation of cognitive impairment and sleep quality

BACKGROUND

The acceleration of aging and the increase in life expectancy have resulted in an increasing number of older adults developing physical and mental comorbidities. We examined the association between depression and quality of life (QoL) using cognitive impairment (COI) as a mediator and sleep quality (SQ) as a moderator among older adults with type 2 diabetes.

METHODS

A total of 2646 participants from Weifang, Shandong, China completed the survey. Their depression, cognitive function, SQ, and QoL were assessed. PROCESS was used to investigate mediating and moderating effects.

RESULTS

COI mediated the association between depression and QoL (indirect effect = -0.1058, bootstrapped 95 % CI [-0.1417, -0.0725]). Moderated mediation analyses indicated that SQ moderated the first half of the pathway of depression's impact on QoL through COI (moderating effect = -0.1128, bootstrapped 95 % CI [-0.1981, -0.0348]). Depression negatively impacted cognitive function in participants with poor (vs. better) SQ.

LIMITATIONS

First, multiple assessment tools should be considered to increase objective assessment. Second, the cross-sectional design limited our ability to make causal inferences. Third, additional diabetes-related variables should be included to explore this relationship. Finally, the pathways of influence and mechanisms of action of COI in older adults should be explored further.

CONCLUSION

Depression could impair the QoL of older adults by aggravating their COI. Fortunately, improving patients' SQ may undermine this negative effect. These findings may play an integral role in promoting the psychiatric health of older adults with type 2 diabetes.

Association between body mass index and cognitive impairment in Chinese older adults

Background

The association between body mass index (BMI) and the risk of cognitive impairment remains uncertain. Relatively few studies have analyzed the dose-response relationship between BMI and cognitive impairment. This article utilized nationally representative longitudinal data to assess the association between BMI and cognitive impairment in Chinese older adults.

Objective

The present study aimed to analyze the association between BMI and cognitive impairment in Chinese older people, including an investigation of gender differences and the dose-response relationship.

Methods

Data were obtained from the China Health and Retirement Longitudinal Study database in 2015 and 2018. The present study used logistic regression to analyze the relationship between baseline BMI and cognitive impairment, and adopted a restricted cubic spline model to plot dose-response curves for baseline BMI and prevalence of risk of cognitive impairment.

Results

The mean BMI of the survey population was 23.48 ± 3.66 kg/m2, and the detection rate of cognitive impairment was 34.2%. Compared to the normal weight group (18.5 ≤ BMI < 23.9 kg/m2), the odds ratio (OR) for cognitive impairment was 1.473 (95% CI: 1.189-1.823) in the underweight group (BMI < 18.5 kg/m2), whereas the corresponding OR was 0.874 (95% CI: 0.776-0.985) for the overweight or obese group (BMI ≥ 24.0 kg/m2) after adjusting for confounders. Gender subgroup analysis showed that overweight or obese older women were less likely to develop cognitive impairment (OR = 0.843; 95% CI: 0.720-0.987). The results of the restricted cubic spline analysis revealed a curvilinear L-shaped relationship between BMI and the risk of cognitive impairment (P non-linearity <0.05). In particular, the risk of cognitive impairment was higher at a lower baseline BMI. In contrast, BMI in the range of 23.2-27.8 kg/m2 was associated with a decreased risk of cognitive impairment.

Conclusion

BMI is a dose-dependent related factor for cognitive impairment in Chinese older adults. Being underweight is a risk factor for the development of cognitive impairment, while being overweight or obese is less likely to have cognitive impairment, particularly in female older people. Keeping BMI ranging from 23.2-27.8 kg/m2 in older adults can help maintain cognitive function.

The relationships between plasma advanced glycation end products level and cognitive function in middle-aged and elderly Chinese subjects

OBJECTIVES

To determine the relationships between circulating representative advanced glycation end products (AGEs) and cognitive performance in middle-aged and elderly Chinese adults.

METHOD

A cross-sectional study with 1834 participants were included. Cognitive performance was assessed using the Mini-Mental State Examination (MMSE). Plasma free AGEs including Nε-carboxymethyl-L-lysine (CML), Nε-(1-carboxyethyl) lysine (CEL), S-carboxymethyl-L-cysteine (CMC) and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were measured by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Multivariate adjusted linear and logistic regression analysis were used to explore the associations between plasma AGEs and cognitive function.

RESULTS

The prevalence of mild cognitive impairment (MCI) was 17.94%. Plasma CMC and MG-H1 level were negatively associated with MMSE score (β = -0.42, p < 0.001 for all) in the multivariate linear regression analysis. In the multivariate logistic regression analysis, compared to the lowest tertile, participants within the highest tertile of CMC and MG-H1 had increased risk of MCI [ORs (95% CI): 1.62 (1.21-2.17), P trend <0.001, and ORs (95% CI): 1.30 (0.97-1.76), P trend = 0.069, respectively]. In addition, the weighted quantile sum (WQS) index was negatively associated with MMSE (β = -0.48, P < 0.001) and increased risk of MCI [ORs (95% CI): 1.35 (1.20-1.52), P < 0.001].

CONCLUSION

Combined exposure of plasma free AGEs including CML, CEL, CMC and MG-H1 were associated with increased risk of cognitive impairment. Plasma CMC and MG-H1 might the main contributors for cognitive impairment, while further longitudinal studies are required to verify the associations.

A risk prediction model based on machine learning for early cognitive impairment in hypertension: Development and validation study

Background

Clinical practice guidelines recommend early identification of cognitive impairment in individuals with hypertension with the help of risk prediction tools based on risk factors.

Objective

The aim of this study was to develop a superior machine learning model based on easily collected variables to predict the risk of early cognitive impairment in hypertensive individuals, which could be used to optimize early cognitive impairment risk assessment strategies.

Methods

For this cross-sectional study, 733 patients with hypertension (aged 30-85, 48.98% male) enrolled in multi-center hospitals in China were divided into a training group (70%) and a validation group (30%). After least absolute shrinkage and selection operator (LASSO) regression analysis with 5-fold cross-validation determined the modeling variables, three machine learning classifiers, logistic regression (LR), XGBoost (XGB), and gaussian naive bayes (GNB), were developed. The area under the ROC curve (AUC), accuracy, sensitivity, specificity, and F1 score were used to evaluate the model performance. Shape Additive explanation (SHAP) analysis was performed to rank feature importance. Further decision curve analysis (DCA) assessed the clinical performance of the established model and visualized it by nomogram.

Results

Hip circumference, age, education levels, and physical activity were considered significant predictors of early cognitive impairment in hypertension. The AUC (0.88), F1 score (0.59), accuracy (0.81), sensitivity (0.84), and specificity (0.80) of the XGB model were superior to LR and GNB classifiers.

Conclusion

The XGB model based on hip circumference, age, educational level, and physical activity has superior predictive performance and it shows promise in predicting the risk of cognitive impairment in hypertensive clinical settings.

Gender differences in the modifying effect of living arrangements on the association of sleep quality with cognitive function among community-dwelling older adults: a cross-sectional study

Background

Sleep quality is considered to be associated with cognitive function for older adults, but little is known about whether living with others can buffer mild cognitive impairment in older adults with poor sleep quality. The objective of this study was to examine the role of living arrangements in sleep quality and cognitive function among older adults aged 65 and over.

Methods

2,859 older adults over 65 years old were selected by using multi-stage stratified sampling method. Cognitive function and sleep quality were measured using Mini-Mental State Examination (MMSE) and Pittsburgh Sleep Quality Index (PSQI). Binary logistic regression was performed to examine the relationship between sleep quality and mild cognitive impairment, and the interaction effects of sleep quality and living arrangements on mild cognitive impairment stratified by gender.

Results

Poor sleep quality was associated with mild cognitive impairment among men and women regardless of living arrangements. The significantly protective role of living with others in reducing the incidence of mild cognitive impairment was found in men with poor sleep quality, but not in women.

Conclusion

Targeted support for older adults with poor sleep quality may be effective in preventing mild cognitive impairment, and gender differences should be taken into account when promoting cohabitations.

Longitudinal associations between sleep duration and cognitive impairment in Chinese elderly

BACKGROUND

Age-associated cognitive decline has become a major threat to both personal welfare and public health and can further develop into Dementia/Alzheimer's disease. Sleep is significantly correlated with cognitive function, but both cognitive impairment and sleep problems increase with normal aging. This study explored how sleep duration affects cognitive performance among older adults in China.

METHODS

Using data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2014 and 2018, cognitive function was assessed via the Mini-Mental State Examination (MMSE), which included five domains: orientation, registration, attention or calculation, recall, and language. Logistic regression was used to examine whether the change in sleep duration was a risk factor for cognitive impairment. We also used multinomial logistic regression to study the impact of sleep duration and the changes in sleep duration on cognitive changes during the follow-up period.

RESULTS

The empirical study showed a U-shaped relationship between sleep duration and increased risk of cognitive impairment. Short (< 6 hours) and long (> 8 hours) sleep durations were positively associated with cognitive impairment. Tests of interactions between sleep duration and sleep quality showed that short sleep durations with fair sleep quality had an increased risk of cognitive impairment. Further, the participants were divided into three groups: normal cognition (MMSE > 24), mild cognitive impairment (MCI, 18 ≤ MMSE score ≤ 24), and severe cognitive impairment (MMSE < 18). First, of the participants with normal cognition at baseline, those who sleeping > 7 h at follow-up and > 7 h at both baseline and 4-year follow-up assessments could increase the risk of cognitive impairment. Second, for individuals with MCI at baseline, those who transitioned to sleeping > 7 h at follow-up period and > 7 h at both baseline and 4-year follow-up assessments had a lower chance of reverting to normal cognition.

CONCLUSION

Excessive sleep may be a major risk for cognitive impairment among older adults. Furthermore, a moderate amount of sleep could be a possible strategy to prevent cognitive impairment.

Interactive Effects of Methionine and Lead Intake on Cognitive Function among Chinese Adults

The association between methionine intake and cognitive function is inconclusive. We aimed to assess the association between methionine intake and cognitive function in Chinese adults and to explore the interaction between methionine and lead intake. Data from 4852 adults aged ≥55 years from the China Health and Nutrition Survey were used. Cognitive function was measured in 1997, 2000, 2004, and 2006. A 3-day, 24-hour recall was used to assess methionine and lead intake from different protein sources. Multivariable mixed linear regression was used in the analyses. Total methionine intake was positively correlated with cognition. There was a significant interaction between animal methionine and lead intakes. In subgroup analyses, across the quartiles of animal methionine intake, the regression coefficients (95% CI) for global cognition were 0.00, 0.57 (0.17 to 0.98), 1.18 (0.73 to 1.62), and 1.80 (1.31 to 2.29), respectively, while they were 0.00, -0.73 (-1.12 to -0.34), -0.83 (-1.26 to -0.41), and -1.72 (-2.22 to -1.22) across the quartiles of plant methionine intake, respectivelyThe association between animal methionine intake and cognition was stronger among adults with a low lead intake. In conclusion, animal methionine and plant methionine intake were positively and inversely associated with cognition, respectively. Lead intake modified the association between animal methionine intake and cognition.