Association of Vision Loss With Cognition in Older Adults

Self-reported sensory impairment and social participation among Korean older adults: mediating roles of cognitive function and digital technology use

OBJECTIVES

This study investigates the correlation between self-reported sensory impairment, cognitive function, digital technology use, and social participation among older adults in South Korea.

METHOD

Data from the 2020 National Survey of Older Koreans, comprising a nationally representative sample of 7849 individuals aged 65 years or older, were analyzed. A serial mediation analysis (Model = 6) was conducted using the PROCESS macro for SPSS.

RESULTS

Following adjustment for covariates, cognitive function and digital technology use serially mediated the relationship between self-reported sensory impairment and social participation among older adults (B = -0.0020, SE = 0.0005, 95% confidence interval [CI] = [-0.0030, -0.0010]). Specifically, self-reported sensory impairment exhibited a negative correlation with cognitive function (B = -0.3277, SE = 0.0753, p < .001), which was positively associated with digital technology use (B = 0.0763, SE = 0.0056, p < .001), subsequently linking to enhanced social participation (B = 0.0784, SE = 0.0037, p < .001).

CONCLUSION

Through cross-sectional analysis, this study confirms that self-reported sensory impairment in older adults may precede cognitive decline, hindering digital technology use and reducing social participation. Early diagnosis and treatment are crucial in preventing cognitive decline, while age-friendly digital devices may alleviate cognitive burden and promote social engagement.

Selenium intake is an effective strategy for the improvement of cognitive decline in low cognition older Americans

Age-related cognitive decline is a prominent concern in older adults and selenium (Se) deficiency has been found to be associated with cognitive deficits. For the first time, the present study explored the association between Se intake and cognitive performance in older people with/without cognitive impairment using the data from the National Health and Nutrition Examination Survey 2011-2014. Weighted linear regression models were conducted to evaluate the association between dietary Se/total Se intakes and cognitive assessments. A total of 2387 participants were included. The significant positive association between dietary Se/total Se intakes and total scores of cognitive functioning tests existed only in the older people with low cognitive performance (p < 0.001), not in those with normal cognitive performance. In conclusion, Se intake was beneficial for cognitive decline only in the low cognition older people but failed in normal cognition older people.

Sarcopenia and cognitive impairment in older adults: Long-term prognostic implications based on the National Health and Nutrition Examination Survey (2011-2014)

AIMS

The relationship between sarcopenia and cognitive impairment in older adults remains contentious. This study investigates this association and examines the long-term prognosis for individuals with both conditions.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014, this study focuses on the correlation between sarcopenia and cognitive impairment, as well as the extended prognosis for individuals managing these conditions.

RESULTS

The study cohort comprised 2890 participants, with 648 (22.4 %) diagnosed with sarcopenia. Multivariable logistic regression analysis identified a significant association between sarcopenia and an increased risk of cognitive impairment (adjusted odds ratio [aOR]: 1.68, 95 % confidence interval [CI]: 1.30-2.17). Over a median follow-up period of 48 months, 200 individuals (6.9 %) succumbed to cardiovascular and cerebrovascular diseases (CCVDs), including hypertension, congestive heart failure, coronary artery disease, and stroke, as well as Alzheimer's disease (AD). Participants had comorbid conditions such as CCVDs and diabetes mellitus. Kaplan-Meier survival analysis and the Cox proportional hazards model indicated that individuals with both sarcopenia and cognitive impairment had the highest mortality risk from CCVDs and AD (adjusted hazard ratio [aHR]: 2.73, 95 % CI: 1.48-5.02). Individuals with sarcopenia and comorbidities exhibited a higher mortality risk from CCVDs or AD compared to those without sarcopenia but with comorbidities (aHR: 2.71, 95 % CI: 1.37-5.37).

CONCLUSION

Sarcopenia is independently associated with cognitive impairment. Older adults with both sarcopenia and cognitive impairment or concurrent comorbidities face increased mortality risks from CCVDs or AD compared to their healthy counterparts.

CLINICAL IMPLICATION

Cohort comparison of vision and hearing in 75- and 80-year-old men and women born 28 years apart

PURPOSE

We compared the vision and hearing of older men and women born 28 years apart. In addition, we explored factors explaining the possible cohort differences.

METHODS

Two independent cohorts of 75- and 80-year-old men and women were assessed as a part of the Evergreen study in 1989-1990 (n = 500) and the Evergreen II study in 2017-2018 (n = 726). Studies were conducted with similar protocols, and differences between cohorts were compared for distance visual acuity and hearing acuity. We also studied whether educational level and health factors (i.e. total cholesterol, blood pressure, BMI, and smoking status) underlie the possible cohort differences. Independent samples t-test, Pearson chi-squared test, and linear regression analyses were used as statistical analyses.

RESULTS

Across age and sex groups, the later-born cohort had better visual acuity and a lower prevalence of visual impairment compared to the earlier-born cohort. In hearing, 75-year-old men in the later-born cohort had better hearing acuity, with average hearing level at 32 dB compared to 36 dB in the earlier-born cohort, and 80-year-old men had a lower prevalence of moderate or worse hearing loss (74 % vs. 54 %) than men in the earlier-born cohort. Similar differences were not observed for women. The cohort differences in distance visual acuity and hearing acuity attenuated when adjusting for education level.

CONCLUSIONS

Today older adults retain better vision longer than before, but cohort differences in hearing are less obvious. Differences between cohorts may be partly due to advances in education.

The association between arthritis and cognitive function impairment in the older adults: Based on the NHANES 2011-2014

OBJECTIVE

Arthritis has been postulated as a prevalent potential risk factor for the emergence of dementia and cognitive impairment. This conjecture prompted an examination of the correlation between arthritis and cognitive impairment using the National Health and Nutrition Examination Survey (NHANES) repository. The analysis was meticulously adjusted for potential confounders such as age and assorted systemic comorbidities, to ensure robustness in the results obtained.

METHODS

Among 2,398 adults aged 60 years and above, logistic regression and cubic spline models were employed to elucidate the relationship between arthritis and cognitive performance. This was assessed utilizing tests such as Immediate Recall test (IRT), Delayed Recall test (DRT), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST).

RESULTS

In our investigation, a total of 19931 individuals were analyzed, among which 2,398 patients (12.03%) were identified with arthritis. Subjects with arthritis inflammation had lower DSST and AFT scores compared to the healthy group, indicating cognitive decline. After adjusting for all covariates, arthritis was significantly associated with higher DSST and AFT scores by logistic regression modeling (OR: 0.796, 95% CI: 0.649-0.975; OR: 0.769, 95% CI: 0.611-0.968).

CONCLUSION

Our analysis underscores the potential linkage between arthritis prevalence and cognitive impairment within a nationally representative of US older adults.

Association of serum n-3 and n-6 docosapentaenoic acids with cognitive performance in elderly adults: National Health and Nutrition Examination Survey 2011-2014

Limited information exists on the influence of docosapentaenoic acid (DPA) on cognitive function. We investigated the association between serum n-3 and n-6 DPAs and cognitive performance in an elderly population from the National Health and Nutrition Examination Survey, 2011-2014. Restricted cubic spline and logistic regression analyses were utilized. A total of 1,366 older participants were included. Elevated proportions of DPA(n3) in total serum fatty acids were slightly associated with higher DSST scores (OR 0.61, 95% CI (0.38-0.97)), and higher proportions of DPA(n6) in total serum fatty acids were significantly associated with lower scores on different cognitive tests (CERAD (1.64, 1.02-2.65), AFT (2.31, 1.43- 3.75), DSST (3.21, 1.98-5.22) and global cognition (2.85, 1.74-4.66)). After multivariable adjustment, DPA(n3) exhibited no association with cognitive performance, whereas DPA(n6) remained correlated with AFT (1.98, 1.13-3.48), DSST (2.63, 1.43-4.82) and global cognition (2.15, 1.19-3.90). In stratified analyses, higher levels of DPA(n3) were associated with better performance in CERAD among participants aged ≥70, in DSST among those without diabetes and in global cognition among people with lower incomes. Increased DPA(n6) levels were associated with worse performance in AFT and DSST among those aged 60-70 and in all cognitive tests among those with better incomes. In conclusions, elevated levels of serum DPA(n3) may be beneficial for cognitive performance among elderly adults, especially in those over 70 years, with lower incomes and without diabetes. Serum n-6 DPA might be negatively associated with cognitive function, and this association is more pronounced among those who aged 60-70 with higher incomes.

Association between low cognitive performance and diabetes-related health indicators across racial and ethnic groups in adults with diabetes

AIM

To examine the associations between low cognitive performance (LCP) and diabetes-related health indicators (including body mass index [BMI], HbA1c, systolic blood pressure [SBP], low-density lipoprotein [LDL] and self-reported poor physical health) and whether these associations vary across racial/ethnic subgroups.

METHODS

We identified adults aged 60 years or older with self-reported diabetes from the 2011-2014 National Health and Nutrition Examination Survey. Individuals with cognitive test scores in the lowest quartile were defined as having LCP. We used regression models to measure the associations of LCP with diabetes-related biometrics (BMI, HbA1c, SBP and LDL); and self-reported poor physical health. Moreover, we explored potential variations in these associations across racial/ethnic subgroups.

RESULTS

Of 873 (261 with LCP) adults with diabetes, LCP was associated with higher HbA1c, SBP and LDL (adjusted difference: 0.41%, 5.01 mmHg and 5.08 mg/dL, respectively; P < .05), and greater odds of reporting poor physical health (adjusted odds ratio: 1.59, P < .05). The association between LCP and HbA1c was consistent across racial/ethnic groups, and notably pronounced in Hispanic and Other. BMI worsened with LCP, except for non-Hispanic Black. Excluding the Other group, elevated SBP was observed in people with LCP, with Hispanic showing the most significant association. LDL levels were elevated with LCP for Hispanic and Other. Physical health worsened with LCP for both non-Hispanic Black and Hispanic.

CONCLUSIONS

We quantified the association between LCP and diabetes-related health indicators. These associations were more pronounced in Hispanic and Other racial/ethnic groups.

Cognitive frailty in relation to vitamin B12 and 25-hydroxyvitamin D in an elderly population: a cross-sectional study from NHANES

Background

Nutritional support has been identified as a potential intervention for cognitive frailty; however, the association between 25-hydroxyvitamin D [25-(OH)D], vitamin B12, and cognitive frailty remains ambiguous.

Methods

This study utilized data from two cycles (2011-2012, 2013-2014) of the National Health and Nutrition Examination Survey (NHANES) to investigate this relationship. The researchers constructed a 41-item frailty index encompassing diverse aspects of physical functioning, psychological evaluation, and medical conditions, and evaluated each participant individually. The study utilized Spearman's rank correlation coefficient and univariate ordered logistic regression to assess the relationships between variables and cognitive frailty. Recursive feature elimination and cross-validation methods were employed to identify the most influential variables for building and optimizing multivariate ordered logistic regression models. Subgroup analyses and interaction tests were further conducted to validate the identified correlations.

Results

The findings of this study confirm a negative linear correlation between 25-(OH)D levels and cognitive frailty in older adults. Specifically, a one-unit increase in 25-(OH)D levels was associated with a 12% reduction in the risk of cognitive frailty. The result was further supported by subgroup analyses and interaction tests.

Conclusion

The existence of a negatively correlated linear association between 25-(OH)D levels and cognitive frailty in older adults is plausible, but further rigorously designed longitudinal studies are necessary to validate this relationship.

Value proposition of retinal imaging in Alzheimer's disease screening: A review of eight evolving trends

Alzheimer's disease (AD) is the leading cause of dementia worldwide. Current diagnostic modalities of AD generally focus on detecting the presence of amyloid β and tau protein in the brain (for example, positron emission tomography [PET] and cerebrospinal fluid testing), but these are limited by their high cost, invasiveness, and lack of expertise. Retinal imaging exhibits potential in AD screening and risk stratification, as the retina provides a platform for the optical visualization of the central nervous system in vivo, with vascular and neuronal changes that mirror brain pathology. Given the paradigm shift brought by advances in artificial intelligence and the emergence of disease-modifying therapies, this article aims to summarize and review the current literature to highlight 8 trends in an evolving landscape regarding the role and potential value of retinal imaging in AD screening.

Non-linear association of liver enzymes with cognitive performance in the elderly: A cross-sectional study

BACKGROUND

Although liver metabolic dysfunction has been found to potentially elevate susceptibility to cognitive impairment and dementia, there is still insufficient evidence to explore the non-linear association of liver enzymes with cognitive performance. Therefore, we aimed to elucidate the non-linear relationship between liver enzymes and cognitive performance.

METHODS

In this cross-sectional study, 2764 individuals aged ≥ 60 who participated in the National Health and Nutrition Survey (NHANES) between 2011 and 2014 were included. The primary data comprised liver enzyme levels (alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST/ALT ratio, and gamma-glutamyl transferase (GGT)), and cognitive performance was the major measured outcome. The associations were analyzed using weighted multivariate logistic regression, subgroup analysis, a generalized additive model, smooth fitting curves, and threshold effects.

RESULTS

The results of the fully adjusted model indicated that ALP was negatively associated with the animal fluency test (AFT) score (OR = 1.48, 95% CI: 1.11-1.98), whereas ALT demonstrated a positive association with the consortium to establish a registry for Alzheimer's disease (CERAD) test score (OR = 0.72, 95% CI: 0.53-0.97). Additionally, the AST/ALT ratio was negatively associated with the global cognitive test (OR = 2.39, 95% CI: 1.53-3.73), CERAD (OR = 2.61, 95% CI: 1.77-3.84), and digit symbol substitution test (DSST) scores (OR = 2.51, 95% CI: 1.57-4.02). GGT was also negatively associated with the AFT score (OR = 1.16, 95% CI: 1.01-1.33) in unadjusted model. A non-linear relationship was observed between liver enzymes and the risk of cognitive impairment as assessed by the global cognitive test. Specifically, when ALP > 60 U/L, 0.77 < AST/ALT < 1.76, and 25 < GGT < 94 U/L, higher liver enzyme levels were significantly associated with an elevated cognitive impairment risk, while a lower cognitive impairment risk when ALT level was > 17 U/L.

CONCLUSIONS

There is a non-linear relationship between liver enzymes and cognitive performance, indicating that liver enzyme levels should be maintained within a certain level to mitigate the risk of cognitive impairment.

Very high high-density lipoprotein cholesterol may be associated with higher risk of cognitive impairment in older adults

BACKGROUND

Previous studies have shown that high-density lipoprotein cholesterol (HDL-C) levels are positively associated with cognitive function across a range of concentrations. However, recent studies have suggested that very high HDL-C levels may lead to poorer outcomes. Therefore, we aimed to investigate the relationship between different concentrations of HDL-C and cognitive impairment risk.

METHODS

We collected data from 3632 participants aged over 60 years from the U.S. National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014 to assess the relationship between HDL-C and cognitive function. Cognitive function was evaluated with the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, the animal fluency test (AFT), and the digit symbol substitution test (DSST). We used restricted cubic spline models and logistic regression to examine the association between HDL-C and cognitive function.

RESULTS

A U-shaped was observed between HDL-C and cognitive outcomes, individuals with higher risk in those with both low and very high HDL-C levels compared with those with midrange values. Very high HDL-C levels (≥ 2.50 mmol/L) were associated with increased risk of cognitive impairment (OR = 2.19; 95% CI, 1.12-4.28) compared with those with HDL-C levels in the range of 1.50 to 1.99 mmol/L in older adults after adjustment for confounding factors. Interaction test demonstrated that relationship between very high HDL-C and the risk of cognitive impairment was not changed in different sex and race group (P for interaction > 0.05).

CONCLUSIONS

Very high HDL-C levels were associated with an increased risk of cognitive impairment. HDL-C may not be a protective factor for maintaining brain health in older adults at very high levels.

Mediation effect of cognitive impairment for the relationship of type 2 diabetes mellitus with mortality among elderly individuals

Objectives

To investigate the potential mediating role of cognitive impairment on the link between type 2 diabetes mellitus (T2DM) and mortality among elderly individuals using data from the National Health and Nutrition Examination Survey (NHANES) database.

Methods

Totally, 1,891 individuals from the NHANES database were included in this cohort study. All-cause mortality was considered study endpoint. Cognitive impairment was assessed by digit symbol substitution test (DSST). Adopted weighted logistic regression analyses to explore the relationship of T2DM with cognitive impairment. Constructed weighted Cox proportional hazard models to investigate the relationship of T2DM with all-cause mortality. We employed distribution-of-the-product method to investigate the mediating effect. RMediation software package was used to calculate the 95% confidence interval (CI) of the distribution-of-the-product. If CI does not contain 0, it suggests a significant mediation effect.

Results

The findings from the weighted logistic regression revealed that individuals with T2DM had a significantly higher likelihood of experiencing cognitive impairment [odds ratio =1.86, 95% CI: 1.39-2.49]. The result showed that T2DM was related to an increased all-cause mortality (hazard ratio=1.37, 95%CI: 1.01-1.87). Importantly, the mediation effect of cognitive impairment on the relationship of T2DM with all-cause mortality is significant (95%CI: 0.06-0.59). The percentage of mediation effect was calculated as 16.2%.

Conclusion

Our study suggested that the presence of cognitive impairment plays a significant role in explaining the link between T2DM and all-cause mortality in older individuals.

Hidden dangers: Does multisensory impairments accompanying visual impairment increase dementia risk

BACKGROUND

Growing evidence suggests that sensory impairment, particularly in the form of visual impairment, may contribute to the development of dementia. However, it remains unclear whether experiencing concurrent visual impairment in combination with other types of multisensory impairments may further increase this risk.

METHODS

The study used data from the UK Biobank cohort study, which recruited 500,000 adults. With meticulous screening procedures in place, individuals with visual impairment, hearing impairment, and oral health issues were identified for further follow-up evaluations. A multivariable regression analysis was conducted to investigate the relationship between multisensory impairments concurrent with visual impairment and cognitive function. Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals to evaluate the association between multisensory impairments concurrent with visual impairment and dementia risk.

RESULTS

Subjects experiencing multisensory impairments concurrent with visual impairment demonstrated a negative association with cognitive function. Notably, individuals who have both vision and hearing impairments had a significantly higher risk of developing dementia (HR 1.28, 95% CI [1.01-1.63]). Additionally, individuals who experience vision impairment and oral health issues simultaneously were also at higher risk for dementia (HR 1.61, 95% CI [1.32-1.97]). Furthermore, the risk of dementia among individuals with vision impairment, hearing impairment, and oral health issues further escalated to an even higher level (HR 1.63, 95% CI [1.19-2.24]).

CONCLUSIONS

The correlation between the presence of multisensory impairments concurrent with visual impairment and cognitive decline is highly significant. Those with multisensory impairments concurrent with visual impairment are at a significantly increased risk of developing dementia.

Association between hearing ability and cortical morphology in the elderly: multiparametric mapping, cognitive relevance, and neurobiological underpinnings

BACKGROUND

Hearing impairment is a common condition in the elderly. However, a comprehensive understanding of its neural correlates is still lacking.

METHODS

We recruited 284 elderly adults who underwent structural MRI, magnetic resonance spectroscopy, audiometry, and cognitive assessments. Individual hearing abilities indexed by pure tone average (PTA) were correlated with multiple structural MRI-derived cortical morphological indices. For regions showing significant correlations, mediation analyses were performed to examine their role in the relationship between hearing ability and cognitive function. Finally, the correlation maps between hearing ability and cortical morphology were linked with publicly available connectomic gradient, transcriptomic, and neurotransmitter maps.

FINDINGS

Poorer hearing was related to cortical thickness (CT) reductions in widespread regions and gyrification index (GI) reductions in the right Area 52 and Insular Granular Complex. The GI in the right Area 52 mediated the relationship between hearing ability and executive function. This mediating effect was further modulated by glutamate and N-acetylaspartate levels in the right auditory region. The PTA-CT correlation map followed microstructural connectomic hierarchy, were related to genes involved in certain biological processes (e.g., glutamate metabolic process), cell types (e.g., excitatory neurons and astrocytes), and developmental stages (i.e., childhood to young adulthood), and covaried with dopamine receptor 1, dopamine transporter, and fluorodopa. The PTA-GI correlation map was related to 5-hydroxytryptamine receptor 2a.

INTERPRETATION

Poorer hearing is associated with cortical thinning and folding reductions, which may be engaged in the relationship between hearing impairment and cognitive decline in the elderly and have different neurobiological substrates.

FUNDING

See the Acknowledgements section.

Association between serum 25-hydroxyvitamin D3 level and cognitive impairment in older chronic kidney disease patients

This study aims to examine whether hypovitaminosis D was associated with cognitive impairment among chronic kidney patients with different level of albuminuria. This population-based cross-sectional study was conducted on elderly (over 60 years old) with urine albumin to creatinine ratio (UACR) ≥ 30 mg/g from 2011 to 2014 in the US National Health and Nutrition Examination Survey (NHANES). Cognitive function was assessed by the Consortium to Establish a Registry for Alzheimer's Disease Word List Learning (CERAD). Subjects were divided into 2 groups according to the absence or presence of cognitive impairment and a propensity score matching (PSM) was further conducted. The association was assessed with Spearman correlation and logistic regression analysis. The positive association of 25-hydroxyvitamin D3 (25(OH)D3) and cognitive score was presented. PSM analysis revealed that a higher level of 25(OH)D3 correlated to a better cognitive function in CKD patients with albuminuria, especially in patients with 30 mg/g ≤ UACR < 300 mg/g. This study indicated that a low 25(OH)D3 level was associated with poor cognitive performance, especially in patients with microalbuminuria. Thus, early diagnosis of vitamin D insufficiency and an effective intervention might be a useful therapeutic strategy to prevent cognitive decline in patients with the progression of renal dysfunction.

A nomogram to predict cognitive function impairment in patients with chronic kidney disease: A national cross-sectional survey

Background

Cognitive function impairment (CFI) is common in patients with chronic kidney disease (CKD) and significantly impacts treatment adherence and quality of life. This study aims to create a simplified nomogram for early CFI risk detection.

Methods

Data were obtained from the National Health and Nutrition Examination Survey cycles spanning from 1999 to 2002 and again from 2011 to 2014. Stepwise logistic regression was used to select variables and construct a CFI risk prediction model. Furthermore, C-statistic and Brier Score (BS) assessed model performance. Additionally, Kaplan-Meier survival curves were utilised to assess risk group-death prognosis relationships.

Results

Of the 545 participants in the CKD model development cohort, a total of 146 (26.8 %) had CFI. The final model included the variables of age, race, education, annual family income, body mass index, estimated glomerular filtration rate, serum albumin and uric acid. The model had a C-statistic of 0.808 (95 % confidence interval (CI): 0.769-0.847) and a BS of 0.149. Furthermore, the 5-fold cross-validation internal C-statistic was 0.764 (interquartile range: 0.763-0.807) and BS was 0.154. Upon external validation, the model's C-statistic decreased to 0.752 (95 % CI: 0.654-0.850) and its BS increased to 0.182. The Kaplan-Meier survival curves demonstrated that intermediate-to-high-risk participants had shorter overall survival time than low-risk participants (log-rank test: p = 0.00042).

Conclusions

This study established an effective nomogram for predicting CFI in patients with CKD, which can be used for the early detection of CFI and guide the treatment of patients with CKD.

Handgrip strength is associated with cognitive function in older patients with stage 3-5 chronic kidney disease: results from the NHANES

In this study, we aimed to investigate the association between handgrip strength (HGS) and cognitive performance in stage 3-5 chronic kidney disease (CKD) patients aged ≥ 60 years. This cross-sectional study analyzed data from National Health and Nutrition Examination Survey (NHANES) database 2011-2014. Three tests were used to assess the cognitive performance, including consortium to establish a registry for Alzheimer's disease (CERAD), animal fluency test (AFT), and digit symbol substitution test (DSST). The multivariate linear regression analyses adjusting for confounding factors were utilized to evaluate the association of HGS with cognitive performance. A total of 678 older stage 3-5 CKD patients were included in this study. After adjusting for multiple factors, a higher HGS was positively associated with a higher CERAD-delayed recall and DSST score. In addition, our analysis indicated that HGS probably correlated with better performance of immediate learning ability in male, while working memory, sustained attention, and processing speed in female. HGS may be an important indicator for cognitive deficits in stage 3-5 CKD patients, especially for learning ability and executive function. Further research to explore the sex-specific and domain-specific and possible mechanisms are required.

Effect of visual impairment on subjective cognitive decline in older adults: a cross-sectional study in China

OBJECTIVE

People with visual impairment have more functional limitations associated with subjective cognitive decline (SCD), and those with SCD are extremely susceptible to transitioning to irreversible cognitive impairment. This study aimed to explore if visual impairment is a significant predictor of SCD compared with other socioeconomic and health factors associated with SCD.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

The investigation aimed to assess the factors influencing SCD among 428 participants aged 60 and above in Zhaoyuan, China.

PRIMARY OUTCOME MEASURES

The primary outcome variable was SCD, measured by the Chinese version of SCD questionnaire. Multiple logistic regression and propensity score matching (PSM) were used to analyse the influence of visual impairment on the subjective cognition of the elderly.32.2% of the elderly were experiencing SCD. Older adults with SCD showed a higher prevalence of visual impairment (72.5%) than the elderly without SCD (58.6%) (P=0.006). Multivariate logistic regression analysis showed that bad self-reported health status, lack of physical exercise and visual impairment were the risk factors for SCD in older adults, while more than 9 years of education was a protective factor. In addition, PSM model showed that after eliminating the dominant biases caused by the individual observable heterogeneity of older adults with and without visual impairment, the risk of SCD in the elderly with visual impairment was increased by 13.6%-14.5% and the difference was statistically significant (P<0.05).

CONCLUSIONS

It was found that older adults experiencing visual impairments are at an elevated risk of developing SCD compared with their counterparts without such impairments. Additionally, visual impairment remains a significant risk factor for SCD in the elderly, even adjusting for potential biases arising from individual observable heterogeneity.

Association of cognitive impairment with the interaction between chronic kidney disease and depression: findings from NHANES 2011-2014

BACKGROUND

Cognitive impairment (CoI), chronic kidney disease (CKD), and depression are prevalent among older adults and are interrelated, imposing a significant disease burden. This study evaluates the association of CKD and depression with CoI and explores their potential interactions.

METHOD

Data for this study were sourced from the 2011-2014 National Health and Nutritional Examination Survey (NHANES). Multiple binary logistic regression models assessed the relationship between CKD, depression, and CoI while controlling for confounders. The interactions were measured using the relative excess risk of interaction (RERI), the attributable proportion of interaction (AP), and the synergy index (S).

RESULTS

A total of 2,666 participants (weighted n = 49,251,515) were included in the study, of which 700 (16.00%) had CoI. After adjusting for confounding factors, the risk of CoI was higher in patients with CKD compared to non-CKD participants (odds ratio [OR] = 1.49, 95% confidence interval [CI]:1.12-1.99). The risk of CoI was significantly increased in patients with depression compared to those without (OR = 2.29, 95% CI: 1.73-3.03). Furthermore, there was a significant additive interaction between CKD and depression in terms of the increased risk of CoI (adjusted RERI = 2.01, [95% CI: 0.31-3.71], adjusted AP = 0.50 [95% CI: 0.25-0.75], adjusted S = 2.97 [95% CI: 1.27-6.92]).

CONCLUSION

CKD and depression synergistically affect CoI, particularly when moderate-to-severe depression co-occurs with CKD. Clinicians should be mindful of the combined impact on patients with CoI. Further research is needed to elucidate the underlying mechanisms and assess the effects specific to different CKD stages.

Chronic kidney disease and cognitive performance: NHANES 2011-2014

PURPOSE

Previous studies suggest an association between chronic kidney disease (CKD) and cognitive impairment. The purpose of this study was to explore the association between the diverse stages of CKD and the cognitive performance of elderly American adults.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 were used. Multivariate adjusted logistic regression, subgroup analysis, and the restricted cubic spline model were used to assess the associations of CKD stage and estimated glomerular filtration rate (eGFR) with cognitive performance. The measures used to evaluate cognitive function included the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test, the Animal Fluency test, and the Digit Symbol Substitution test (DSST).

RESULTS

This study included 2234 participants aged ≥ 60 years. According to the fully adjusted model, stages 3-5 CKD were significantly associated with the CERAD test score (OR = 0.70, 95% CI [0.51, 0.97], p = 0.033), the Animal Fluency test score (OR = 0.64, 95% CI [0.48, 0.85], p = 0.005), and the DSST score (OR = 0.60, 95% CI [0.41, 0.88], p = 0.013). In addition, the incidence of poor cognitive function increased with decreasing eGFR, especially for individuals with low and moderate eGFRs. Both the DSST score (p nonlinearity < 0.0001) and the Animal Fluency test score (p nonlinearity = 0.0001) had nonlinear dose-response relationships with the eGFR. However, a linear relationship was shown between the eGFR and CERAD test score (p nonlinearity = 0.073).

CONCLUSIONS

CKD, especially stages3-5 CKD, was significantly associated with poor cognitive performance in terms of executive function, learning, processing speed, concentration, and working memory ability. All adults with CKD should be screened for cognitive impairment.

The Association of Vision and Hearing Impairment on Cognitive Function and Loneliness: Evidence From the Mexican Health and Aging Study

Objectives: We investigated whether self-reported vision and hearing were associated with cognitive function and loneliness among Mexican adults aged 50 and older. Methods: Mexican Health and Aging Study data. Vision/hearing status was self-reported (excellent-very good, good, fair-poor). Cognition was measured using nine tasks. Loneliness was measured using the UCLA Loneliness Scale. Analyses controlled for demographic and health characteristics. Results: Among 12,353 participants (mean age = 67, 58% female), poor vision, but not hearing, was associated with lower global cognition (β = -0.03, p < .05). Poor vision (OR = 1.57, 95% CI = 1.30-1.91) and hearing (OR = 1.35, 95% CI = 1.14-1.61) were associated with higher odds of being lonely after adjusting for demographics and comorbidities, but not when adjusting for limitations in daily activities and depressive symptoms. Discussion: Poor vision is a potentially modifiable risk factor for lower cognition and loneliness among Mexican adults. These associations are partly due to functional characteristics of older adults with poor vision.

Association between cognitive function and body composition in older adults: data from NHANES (1999-2002)

Aim

To investigate the association between cognitive function and body composition in older adults.

Methods

We collected data on 2080 older adults (>60 years of age) from the National Health and Nutrition Examination Survey (NHANES) for the years 1999-2000 and 2001-2002. Candidate variables included: demographic data (sex, age, race, education level, marital status, poverty-to-income ratio), alcohol consumption, cardiovascular disease, diabetes, osteoporosis, total bone mineral density, and total fat mass. A logistic regression model was established to analyze the association between cognitive function and body composition in older adults. In addition, stratified logics regression analysis was performed by sex and age.

Results

Bone mineral density significantly affects cognitive function in older adults (p<0.01). When examining the data according to sex, this correlation is present for women (p < 0.01). For men, though, it is not significant (p = 0.081). Stratified by age, total bone mineral density was significantly correlated with cognitive function in 60-70 and 70-80 years old people, but not in older adults older than 80 years(for 60-70 years old, p = 0.019; for 70-80 years old, p = 0.022). There was no significant correlation between total bone mineral density and cognitive function (p = 0.575).

Conclusion

The decrease of total bone mineral density was significantly correlated with cognitive decline in the older adults, especially among women and older people in the 60 to 80 age group. There was no connection between total fat mass, total percent fat, total lean mass, appendicular lean mass, appendicular lean mass /BMI and cognitive function in the older adults.

Correlation between sarcopenia index and cognitive function in older adult women: A cross-sectional study using NHANES data

OBJECTIVES

The Sarcopenia Index (SI) has the potential as a biomarker for sarcopenia, which is characterized by muscle loss. There is a clear association between sarcopenia and cognitive impairment. However, the relationship between SI and cognitive impairment is yet to be fully understood.

METHODS

We employed data extracted from the U.S. National Health and Nutrition Examination Survey (NHANES) spanning the years 1999 to 2002. Our study encompassed individuals aged 65 to 80 who possessed accessible information regarding both SI and cognitive evaluations with a GFR ≥ 90. Cognitive function was assessed using the digit symbol substitution test (DSST). SI was calculated by serum creatinine (mg/dL)/cystatin C (mg/L)*100. Employing multivariate modeling, we estimated the connection between SI and cognitive performance. Furthermore, to enhance the reliability of our data analysis, we categorized SI using tertiles and subsequently calculated the P-value for trend.

RESULTS

After adjustment for potential confounders, we found SI was significantly and positively correlated with cognitive function scores both in older female in the American population [β = 0.160, 95 % confidence interval (CI) 0.050 to 0.271, P = 0.00461]. Similarly, when the total cognitive function score was treated as a categorical variable according to tertiles, higher SI was related to better total cognitive function scores in females [odds ratio (OR) = 3.968, 95 % CI 1.863 to 6.073, P = 0.00025] following adjustment for confounders.

CONCLUSIONS

Higher SI was correlated with a lower prevalence of cognitive impairment among older adult women with normal kidney function.

Association between 2,4-dichlorophenoxyacetic acid and cognitive impairment in older adults: a cross-sectional study from NHANES 2001-2002 and 2011-2014

BACKGROUND

2,4-Dichlorophenoxyacetic acid (2,4-D) is reported to be the most widely used herbicide in home and garden environments, rendering it commonly encountered in daily life. Despite being ubiquitous, there is a scarcity of studies that have comprehensively assessed the relationship between 2,4-D exposure and cognition using multiple models.

OBJECTIVE

To explore the association between 2,4-D exposure and cognition among older American people.

METHODS

This was a cross-sectional study that included 3 cycles of data from the National Health and Nutrition Examination Survey. Generalized linear models (GLMs), restricted cubic spline (RCS) regression, and generalized additive models (GAMs) were used to assess the relationship between exposure to 2,4-D and cognitive performance by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) word learning sub-test, Digit Symbol Substitution Test (DSST), and Animal Fluency Test (AFT).

RESULTS

A total of 1364 older U.S. adults (60+ years) were included in the study. The GLMs revealed a negative association between median high levels (0.315-0.566 μg/L) of 2,4-D and cognitive impairment on the DSST and AFT, with multivariate-adjusted ORs of 0.403 (95% CI: 0.208-0.781, P = 0.009) and 0.396 (95% CI: 0.159-0.986, P = 0.047); the RCS regression and GAMs revealed a "U" shaped curve, the left part of which is consistent with the result of the GLMs.

IMPACT STATEMENT

There is a U-shaped relationship between human urinary 2,4-D concentrations and cognitive impairment in older U.S. adults, especially in males, so controlling 2,4-D exposure within an appropriate range is particularly important for cognitive function.

Dietary Adherence and Cognitive Performance in Older Adults by Nativity Status: Results from the National Health and Nutrition Examination Survey (NHANES), 2011-2014

Although adherence to dietary guidelines is associated with better cognitive performance, there may be differences by nativity status. This study aimed to investigate the association between adherence to the healthy eating index (HEI) and cognitive performance (CP) among United States (US)-born and foreign-born older adults (60+ years). Data were obtained from the 2011-2014 NHANES (n = 3065). Dietary adherence was assessed with HEI quintiles. CP (adequate vs. low) was examined using word listing (CERAD), animal naming (AFT), and the digit symbol substitution test (DSST). Weighted multivariable logistic regressions were used to examine associations. The US-born participants in higher dietary quintiles had adequate CP when compared to foreign-born participants. In adjusted models, the US-born participants in the highest HEI quintile had increased odds of adequate DSST scores (odds ratio: 1.95, 95% confidence interval: 1.15-3.28) compared with those in the lowest quintile. Patterns of association were generally reversed for foreign-born participants and were non-statistically significant. Future research should consider the influence of diets in delaying or preventing decline in cognition and evaluate nutritional factors that contribute to cognitive outcomes for the foreign-born population.

Interaction between visual impairment and subjective cognitive complaints on physical activity impairment in U.S. older adults: NHANES 2005-2008

BACKGROUND/AIM

To investigate the independent relationships of visual impairment (VI) and Subjective cognitive complaints (SCC) with physical function impairment (PFI) and the interaction effect between VI and SCC on PFI in American older adults.

METHODS

The data of this cross-sectional study was obtained from the 2005-2008 National Health and Examination Survey (NHANES) conducted in the United States. The VI criterion included both subjective self-reported eyesight conditions and objective visual acuity test results. The self-reported questionnaires were utilized to determine PFI and SCC. According to the survey design of NHANS, original data were weighted to produce nationally representative estimates. Both the unweighted original data and weighted estimates underwent analysis. Crude and adjusted logistic models were employed to assess the pairwise associations among VI, SCC, and PFI. To assess the interactive effect, measures such as the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (S) were calculated.

RESULTS

A total of 2,710 subjects (weighted n = 38,966,687) aged 60 years or older were included. Compared with subjects without subjective visual impairment (SVI), those with SVI had a significant positive association with PFI [weighted OR (95%CI): 3.11 (2.25, 4.31)]. After multi-variable adjusting, the relationship remained significant [weighted OR (95%CI): 1.90 (1.32, 2.72)]. Similarly, those with objective visual impairment (OVI) were positively associated with the risk of PFI in the crude model [weighted OR (95%CI): 2.35 (1.53, 3.61)] and adjusted model [weighted OR (95%CI): 1.84 (1.07, 3.17)]. Moreover, we found the association of SCC with an increased risk of FPI [crude weighted OR (95%CI): 5.02 (3.40, 7.40); adjusted weighted OR (95%CI): 3.29 (2.01, 5.38)]. Ultimately, the additive interaction showed there was a significant positive interaction term between SVI and SCC on PFI, while OVI and SCC did not.

CONCLUSION

Both VI and SCC were significantly associated with PFI in elder adults. Besides, there was a significant synergistic interaction between SVI and SCC on PFI, which indicated the improvement of SVI and SCC may be beneficial for the prevention of PFI. For the elderly, especially those with multiple disabilities, comprehensive and targeted approaches are imperative to foster their overall well-being and health.

Increased serum methylmalonic acid levels were associated with the presence of cognitive dysfunction in older chronic kidney disease patients with albuminuria

BACKGROUND

This study aimed to evaluate the correlation between serum methylmalonic acid (MMA) levels and cognition function in patients with chronic kidney disease (CKD).

METHODS

In this cross-sectional study, we included 537 CKD individuals aged ≥ 60-year-old with albuminuria from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Four cognitive tests including the Digit Symbol Substitution Test (DSST), the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Delayed Recall and Word Learning tests, and the Animal Fluency test (AF) were performed. Associations between MMA and cognition scores were assessed with linear regression models.

RESULTS

MMA level was negatively associated with residual renal function and nutrition status. After multivariate adjustment, elevated serum MMA levels were independently correlated with decline of cognition in CKD patients with albuminuria.

CONCLUSION

Our study showed that higher serum MMA levels were independently associated with the presence of cognition dysfunction in CKD patients. The exact pathogenesis of MMA and cognition needs further research.

Relationship between cognitive function and weight-adjusted waist index in people ≥ 60 years old in NHANES 2011-2014

BACKGROUND

Widespread attention has been given to the detrimental effects of obesity on cognitive function. However, there is no evidence on the connection between low cognitive performance and the WWI (weight-adjusted waist index). This study looked into the connection between poor cognitive performance and the WWI in senior Americans.

METHODS

A cross-sectional research study was carried out with information from the NHANES 2011-2014. With multivariate linear regression models, the pertinence between the WWI and low cognitive function in persons older than 60 years was examined. The nonlinear link was described using threshold effect analyses and fitted smoothed curves. Interaction tests and subgroup analysis were also conducted.

RESULTS

The study had 2762 individuals in all, and subjects with higher WWI values were at greater risk for low cognitive function. In the completely adjusted model, the WWI was positively connected with low cognitive performance assessed by CERAD W-L (OR = 1.22, 95% CI 1.03-1.45, p = 0.0239), AFT (OR = 1.30, 95% CI 1.09-1.54, p = 0.0029), and DSST (OR = 1.59, 95% CI 1.30-1.94, p < 0.0001). The effect of each subgroup on the positive correlation between the WWI and low cognitive performance was not significant. The WWI and low cognitive performance as determined by CERAD W-L and AFT had a nonlinear connection (log-likelihood ratio < 0.05).

CONCLUSION

Among older adults in the United States, the risk of low cognitive performance may be positively related to the WWI.

Associations of cataract, cataract surgery with dementia risk: A systematic review and meta-analysis of 448,140 participants

BACKGROUND

Cataract is the leading cause of blindness around the world. Previous investigations have assessed the relationship between cataract, cataract surgery and dementia risk, but their results remain controversial. Herein, we conducted a meta-analysis to evaluate the associations between cataract, cataract surgery and the risk of dementia.

METHODS

We systemically screened the literature from three electronic databases PubMed, EMBASE and CENTRAL until April 2023. The data were collected by two independent researchers. The hazard ratios (HRs) or odds ratios (ORs) from eligible studies with 95% confidence intervals (CIs) were adjusted into the risk ratios (RRs), which were pooled using the random-effects model.

RESULTS

A total of nine studies with 448,140 participants reported the associations between cataract or cataract surgery and the risk of dementia were included in this meta-analysis. The outcomes of our pooled analysis indicated that cataract was associated with an increased risk of all-cause dementia (RR = 1.24, 95% CI, 1.14-1.35, p < .00001), Alzheimer's disease (RR = 1.22, 95% CI, 1.10-1.35, p = .0002) and vascular dementia (RR = 1.29, 95% CI, 1.01-1.66, p = .04). Cataract surgery is associated with a reduction of the dementia risk (RR = 0.74, 95% CI, 0.67-0.81, p < .00001).

CONCLUSIONS

Current evidence from the existing studies supports that cataract is associated with an increased risk of dementia, and cataract surgery may be instrumental in reducing the risk of dementia in patients with cataract.

The Development of Multisensory Integration at the Neuronal Level

Multisensory integration is a fundamental function of the brain. In the typical adult, multisensory neurons' response to paired multisensory (e.g., audiovisual) cues is significantly more robust than the corresponding best unisensory response in many brain regions. Synthesizing sensory signals from multiple modalities can speed up sensory processing and improve the salience of outside events or objects. Despite its significance, multisensory integration is testified to be not a neonatal feature of the brain. Neurons' ability to effectively combine multisensory information does not occur rapidly but develops gradually during early postnatal life (for cats, 4-12 weeks required). Multisensory experience is critical for this developing process. If animals were restricted from sensing normal visual scenes or sounds (deprived of the relevant multisensory experience), the development of the corresponding integrative ability could be blocked until the appropriate multisensory experience is obtained. This section summarizes the extant literature on the development of multisensory integration (mainly using cat superior colliculus as a model), sensory-deprivation-induced cross-modal plasticity, and how sensory experience (sensory exposure and perceptual learning) leads to the plastic change and modification of neural circuits in cortical and subcortical areas.

Serum neurofilament light chain and cognition decline in US elderly: A cross-sectional study

OBJECTIVE

Early identification of cognitive impairment in neurodegenerative diseases like Alzheimer's disease (AD) is crucial. Neurofilament, a potential biomarker for neurological disorders, has gained attention. Our study aims to investigate the relationship between serum neurofilament light (sNfL) levels and cognitive function in elderly individuals in the United States.

METHODS

This cross-sectional study analyzed data from participants aged 60 and above in the National Health and Nutrition Examination Survey (2013-2014). We collected sNfL levels, cognitive function tests, sociodemographic characteristics, comorbidities, and other variables. Weighted multiple linear regression models examined the relationship between ln(sNfL) and cognitive scores. Restricted cubic spline (RCS) visualization explored nonlinear relationships. The stratified analysis examined subgroups' ln(sNfL) and cognitive function association.

RESULTS

The study included 446 participants (47.73% male). Participants with ln(sNfL) levels between 2.58 and 2.81 pg/mL (second quintile) performed relatively well in cognitive tests. After adjusting for multiple factors, ln(sNfL) levels were negatively correlated with cognitive function, with adjusted β (95% CI) as follows: immediate recall test (IRT): -0.763 (-1.301 to -0.224), delayed recall test (DRT): -0.308 (-0.576 to -0.04), animal fluency test (AFT): -1.616 (-2.639 to -0.594), and digit symbol substitution test (DSST): -2.790 (-4.369 to -1.21). RCS curves showed nonlinear relationships between ln(sNfL) and DRT, AFT, with inflection points around 2.7 pg/mL. The stratified analysis revealed a negative correlation between ln(sNfL) and cognition in specific subgroups with distinct features, with an interaction between diabetes and ln(sNfL).

INTERPRETATION

Higher sNfL levels are associated with poorer cognitive function in the elderly population of the United States. sNfL shows promise as a potential biomarker for early identification of cognitive decline.

Sex Differences in the Association Between LDL/HDL with Cognitive Decline in Older Adults: National Health and Nutrition Examination Survey

Background

Lipids have a significant impact on the development and functioning of the nervous system, but the sex differences between the association of LDL/HDL, which reflects lipid metabolic status, and cognitive impairment remains unclear.

Objective

We aimed to determine if there were sex differences between the association of LDL/HDL and cognitive function in US older adults.

Methods

This population-based cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 cycles. The main outcome was poor cognitive performance defined by the Digit Symbol Substitution Test (DSST) <  34 based on published literature.

Results

A total of 1,225 participants were included in the study, with a cognitive impairment incidence of 25.6% (314/1,225). Multivariate regression models demonstrated a significant association between cognitive decline and each 1-unit increase in LDL/HDL, after adjusting for all covariates (adjusted odds ratio [OR] = 1.36, 95% confidence interval [CI]: 1.11-1.67). Furthermore, subgroup analysis revealed an interaction between LDL/HDL and cognitive impairment in sex subgroups.

Conclusions

LDL/HDL was associated with cognitive impairment in the US older adult population in adjusted models, although the significance of this association was not observed in females.

Impact of cataract surgery on cognitive impairment in older people

OBJECTIVES

To examine the impact of cataract surgery on mild cognitive impairment (MCI) and dementia in older people.

METHODS

This prospective observational study included patients aged 75 years and older who underwent cataract surgery between 2019 and 2021. Mini-mental state examination (MMSE) and MMSE for the visually impaired (MMSE-blind) were measured to evaluate cognitive function before and 3 months after cataract surgery. MMSE score at baseline was used to categorize patients into dementia (MMSE ≤ 23) and MCI groups (23 < MMSE ≤ 27). Logistic regression models were used to estimate associations between improvement in cognitive function and other factors.

RESULTS

Of 132 patients screened for inclusion in the study, 88 met the inclusion criteria; 39 patients were assigned to the dementia group (mean age, 85.7 ± 4.2 years) and 49 to the MCI group (mean age, 84.2 ± 3.4 years). The MCI group showed significant improvement from before to after surgery in the MMSE score (25.65 ± 1.03 vs. 27.08 ± 1.99, respectively, p < 0.001) and MMSE-blind score (18.04 ± 1.14 vs. 19.41 ± 2.01, respectively, p < 0.001). Cognitive function improved significantly in the MCI group compared with the dementia group (odds ratio, 2.85; 95% confidence interval, 1.02-7.97; and p = 0.046).

CONCLUSIONS

Cataract surgery significantly increases cognitive test scores in older patients with MCI. After cataract surgery, the likelihood of improvement in cognitive function may be highly dependent on a patient's preoperative cognitive state.

Effect of dietary protein intake on cognitive function in the elderly with chronic kidney disease: analysis of the National Health and Nutrition Examination Survey 2011-2014

BACKGROUND

Cognitive dysfunction is prevalent among the elderly diagnosed with chronic kidney disease (CKD). Low protein diets are used for retarding the progression of CKD in clinical practice. Nonetheless, the impact of dietary protein consumption on cognitive function in this population remains uncertain.

METHODS

We recruited 2306 participants (≥60 years) from 2011 to 2014 National Health and Nutrition Examination Survey (NHANES). 24-h dietary recall questionnaire was utilized to evaluate protein intake. Cognitive function was measured using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST). Participants' characteristics were analyzed, and the interaction between protein consumption and CKD on cognitive impairment were analyzed using a logistic regression model.

RESULTS

We divided participants into three groups based on CKD stages: no CKD, CKD stage G1 to G2 (19%), and CKD stage G3 to G5 (18%). The average protein intake was 0.97 g/(kg·d). In the higher protein intake group, CKD stages G1 to G2 elevated the risk of immediate memory impairment (OR: 2.441, 95% Cl: 1.161-5.132 for protein consumption in 1.0-1.2g/(kg·d); OR: 2.225, 95% Cl: 1.015-4.876 for protein consumption in >1.2 g/(kg·d)). However, no similar resuts were observed in the lower protein intake group. In addition, the interaction between CKD status and protein intake on immediate memory was statistically significant (p = .041).

CONCLUSION

A higher probability of cognitive impairment in the elderly with early-stage CKD may be linked to higher protein intake. Low protein diets may be a potential strategy to release cognitive impairment in the elderly with early-stage CKD.

Association Between Serum Neurofilament Light Chain and Cognitive Performance Among Older Adults in the United States: A Cross-Sectional Study

INTRODUCTION

Serum neurofilament light chain (sNfL) is an emerging biomarker of neuronal damage in several neurological disorders. Its association with cognitive function in the general US population aged 60 years and above is unknown. The aim of this study was to investigate the correlation between sNfL and cognitive function in the general US population aged 60 and above.

METHODS

The data were obtained from the 2013-2014 National Health and Nutrition Examination Survey (NHANES), which include 506 individuals aged 60 or older who met our search criteria. In our study, sNfL levels were divided into two groups based on dichotomization (19.0 pg/mL). After adjusting for multiple covariates, it was found that the high sNfL group (≥ 19.0 pg/mL) had lower cognitive performance than the low sNfL group (< 19.0 pg/mL). This relationship was also stable in subgroup analysis.

CONCLUSION

In this sample of an American elderly population, higher sNfL levels are correlated with lower cognitive performance. Our findings suggest that sNfL may become a potential screening tool for early prediction and confirmation of cognitive damage.

Association between serum iron, blood lead, cadmium, mercury, selenium, manganese and low cognitive performance in old adults from National Health and Nutrition Examination Survey (NHANES): a cross-sectional study

Cognitive decline is a public health problem for the world's ageing population. This study was to evaluate the relationships between serum Fe, blood Pb, Cd, Hg, Se and Mn and cognitive decline in elderly Americans. Data of this cross-sectional study were extracted from the National Health and Nutritional Examination Survey (NHANES 2011-2014). Cognitive performance was measured by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency and Digit Symbol Substitution Test (DSST) tests. Weighted univariable and multivariate logistic regression analyses were used to assess the associations between six trace elements and low cognitive performance. Subgroup analyses based on diabetes and hypertension history were further assessed the associations. A total of 2002 adults over 60 years old were included. After adjusting covariates, elevated serum Fe levels were associated with the decreased risk of low cognitive performance, especially in the elderly without diabetes history and with hypertension history. High blood Cd levels were associated with the high odds of low cognitive performance in old adults with diabetes and hypertension history. Elevated blood Mn levels were connected with low cognitive performance in old hypertensive people. High blood Pb levels were related to the high odds of low cognitive performance, especially in the elderly without diabetes and hypertension history. High blood Se levels were linked to the decreased risk of low cognitive performance in all the elderly. Appropriate Fe, Se supplementation and Fe-, Se-rich foods intake, while reducing exposure to Pb, Cd and Mn may be beneficial for cognitive function in the elderly.

The association between triglyceride-glucose index and cognitive function in nondiabetic elderly: NHANES 2011-2014

BACKGROUND

The relationship between Insulin resistance (IR) evaluated through homeostasis model assessment insulin resistance (HOMA-IR) and cognitive function is controversial among nondiabetic individuals. No study so far has reported the association between the IR evaluated through triglyceride glucose (TyG) index and cognitive function among nondiabetics. This study aims to assess this association among US nondiabetic older elderly.

METHODS

Data were obtained from the 2011-2014 National Health and Nutrition Examination Survey (NHANES). Low cognitive function was evaluated using the Consortium to Establish a Registry for Alzheimer's Disease Battery for immediate word list learning (CERAD-WL) and delayed recall (CERAD-DR) test, the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST). Logistic regression analyses were conducted to compute the odds ratio (OR) and 95% confidential interval (CI) to examine the association between the TyG index (continuous and quartiles) and low cognitive function.

RESULTS

A total of 661 nondiabetic older adults were included with a mean age of 68.62 ± 6.49 years. Compared to the 1st quartile of the TyG index, participants in the TyG index 4th quartile were associated with low cognitive function evaluated through the CERAD test (CERAD-WL and CERAD-DR) [OR: 2.62; 95% CI (1.31, 5.23); P < 0.05]. Subgroup analyses showed that females (ORQ4 VS Q1: 3.07; 95% CI (1.04, 9.05); P < 0.05) and smokers (OR Q4 VS Q1: 2.70; 95% CI (1.01, 7.26); P < 0.05) categories were related with a higher risk of low cognitive function.

CONCLUSIONS

A high TyG index was strongly correlated with low cognitive function evaluated through the CERAD test (CERAD-WL and CERAD-DR) among US nondiabetic older women. The management of IR in women might be beneficial to primarily prevent low cognitive function among nondiabetic older elderly.

Using Objective Vision Measures to Explore the Association of Vision Impairment With Cognition Among Older Adults in the United States

PURPOSE

To evaluate the association between vision impairment (VI) and cognitive function using objective measures.

DESIGN

Cross-sectional analysis with a nationally representative sample.

METHODS

The association between VI and dementia was investigated in a US population-based, nationally representative sample of Medicare beneficiaries, the National Health and Aging Trends Study (NHATS), a nationally representative sample of Medicare beneficiaries aged ≥65 years, using objective vision measures. Exposures included distance VI (>20/40), near VI (>20/40), contrast sensitivity impairment (CSI) (<1.55), any objective VI (distance and near visual acuity, or contrast), and self-reported VI. The main outcome measure was dementia status defined based on survey reports, interviews, and cognitive tests.

RESULTS

A total of 3026 adults were included in this study; the majority were female (55%) and White (82%). The weighted prevalence rates were 10% for distance VI, 22% for near VI, 22% for CSI, 34% for any objective VI, and 7% for self-reported VI. Across all measures of VI, dementia was more than twice as prevalent in adults with VI compared to their peers without (P < .001 for all). In adjusted models, all measures of VI were associated with higher odds of dementia (distance VI: OR 1.74, 95% CI 1.24-2.44; near VI: OR 1.68, 95% CI 1.29-2.18; CSI: OR 1.95, 95% CI 1.45-2.62; any objective VI: OR 1.83, 95% CI 1.43-2.35; self-reported VI: OR 1.86, 95% CI 1.20-2.89).

CONCLUSIONS

In a nationally representative sample of older US adults, VI was associated with increased odds of dementia. These results suggest that maintaining good vision and eye health may help preserve cognitive function in older age, although more research is needed to investigate the potential benefits of interventions that focus on vision and eye health on cognitive outcomes.

Coffee consumption and all-cause and cardiovascular mortality in older adults: should we consider cognitive function?

Background

The association between coffee and mortality risk has been found in most previous studies, and recent studies have found an association between coffee consumption and cognition. However, there is still a lack of research exploring whether the association between coffee and mortality is influenced by cognitive function.

Objective

The purpose of this study was to explore the association of coffee, caffeine intake in coffee and decaffeinated coffee with all-cause mortality and cardiovascular disease (CVD) mortality in older adults with different cognitive performances.

Methods

The study was based on data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Coffee and caffeine consumption data were obtained from two 24-h dietary recalls. Individual cognitive functions were assessed by CERAD-word learning test (CERAD-WLT), animal fluency test (AFT), and digit symbol substitution test (DSST). In addition, principal component analysis (PCA) was performed with the above test scores to create global cognitive score. The lowest quartile of scores was used to classify cognitive performance. Cox regression and restricted cubic spline (RCS) were applied to assess the relationship between coffee and caffeine consumption and mortality.

Results

In the joint effects analysis, we found that those with cognitive impairment and who reported without drinking coffee had the highest risk of all-cause and cardiovascular mortality compared with others. In the analysis of population with cognitive impairment, for all-cause mortality, those who showed cognitive impairment in the AFT displayed a significant negative association between their total coffee consumption and mortality {T3 (HR [95% CI]), 0.495 [0.291-0.840], p = 0.021 (trend analysis)}. For DSST and global cognition, similar results were observed. Whereas for CERAD-WLT, restricted cubic spline (RCS) showed a "U-shaped" association between coffee consumption and mortality. For CVD mortality, a significant negative trend in coffee consumption and death was observed only in people with cognitive impairment in AFT or DSST. In addition, we observed that decaffeinated coffee was associated with reduced mortality in people with cognitive impairment.

Conclusion

Our study suggested that the association between coffee consumption and mortality is influenced by cognition and varies with cognitive impairment in different cognitive domains.

Dementia and cataract surgery in Australia and New Zealand

BACKGROUND

Cataract surgery improves quality of life and reduces cognitive deterioration.

OBJECTIVES

This paper discusses the health implications of low vision, commonly related to cataracts, in older adults. A recent publication reported that cataract surgery reduces the risk of dementia by 30% over 10 years.

METHODS

We searched Medline from inception to January 2023. We also conducted backward and forward citation searches of included studies and set up alerts to identify studies published after the search date. We performed discussion groups with multidisciplinary experts.

RESULTS

This article provides a broad description of the importance of vision for cognitive function. We discuss access to public-funded cataract surgery in Australia and New Zealand and how this impacts population benefits.

CONCLUSIONS

We have evidence that cataract surgery can decrease the risk of dementia. This is an important topic that deserves recognition as part of an overall ageing response by policymakers and health professionals.

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.

Objectively Measured Visual Impairment and Dementia Prevalence in Older Adults in the US

Importance

Estimates of the association between visual impairment (VI) and dementia in the US population are based on self-reported survey data or measures of visual function that are at least 15 years old. Older adults are at high risk of VI and dementia so there is a need for up-to-date national estimates based on objective assessments.

Objective

To estimate the association between VI and dementia in older US adults based on objective visual and cognitive function testing.

Design, Setting, and Participants

This secondary analysis of the 2021 National Health and Aging Trends Study (NHATS), a population-based, nationally representative panel study, included 3817 respondents 71 years and older. Data were analyzed from January to March 2023.

Intervention

In 2021, NHATS incorporated tablet-based tests of distance and near visual acuity and contrast sensitivity (CS) with habitual correction.

Main Outcomes and Measures

VI was defined as distance visual acuity more than 0.30 logMAR, near visual acuity more than 0.30 logMAR, and CS more than 1 SD below the sample mean. Dementia was defined as scoring 1.5 SDs or more below the mean in 1 or more cognitive domains, an AD8 Dementia Screening Interview Score indicating probable dementia, or diagnosed dementia. Poisson regression estimated dementia prevalence ratios adjusted for covariates.

Results

Of 2967 included participants, 1707 (weighted percentage, 55.3%) were female, and the median (IQR) age was 76.9 (77-86) years. The weighted prevalence of dementia was 12.3% (95% CI, 10.9-13.7) and increased with near VI (21.5%; 95% CI, 17.7-25.3), distance VI (mild: 19.1%; 95% CI, 13.0-25.2; moderate, severe, or blind: 32.9%; 95% CI, 24.1- 41.8), and CS impairment (25.9%; 95% CI, 20.5-31.3). Dementia prevalence was higher among participants with near VI and CS impairment than those without (near VI prevalence ratio: 1.40; 95% CI, 1.16-1.69; CS impairment prevalence ratio: 1.31; 95% CI, 1.04-1.66) and among participants with moderate to severe distance VI or blindness (prevalence ratio: 1.72; 95% CI, 1.26-2.35) after adjustment for covariates.

Conclusions and Relevance

In this survey study, all types of objectively measured VI were associated with a higher dementia prevalence. As most VI is preventable, prioritizing vision health may be important for optimizing cognitive function.

The impact of sensory impairments and eye diseases on cognitive function in elderly Chinese: The mediating effects of social participation

Background

Sensory impairments and eye diseases increase the risk of cognitive decline, but little is known regarding their influence on cognitive function in elderly Chinese and the underlying mechanisms. We aimed to explore these influence mechanism from the social participation perspective.

Methods

We selected 2876 respondents aged ≥60 from the China Health and Retirement Longitudinal Study (CHARLS) conducted in 2013, 2015, and 2018. We assessed sensory impairments and eye diseases based on self-reported responses, and evaluated its relation to social participation and cognitive function by fixed-effects regression and mediation effect analysis over a five-year period.

Results

Respondents with visual impairment and cataracts had poor memory and mental status. Compared with near visual impairment, distance visual impairment was associated with a 1.7 times higher likelihood of cognitive decline (correlation coefficient (β) = -0.051; 95% confidence interval (CI) = -0.065, -0.036)). Respondents with hearing impairment had bad memory (β = -0.046; 95% CI = -0.065, -0.036), but not mental status. Social participation partially mediated the relationships of sensory impairments and cataracts with cognitive function in elderly Chinese. Individuals with sensory impairments affected by limited social participation reported a faster cognitive decline compared to those with eye disease.

Conclusions

We found that sensory impairments and eye diseases were negatively associated with cognitive function. Furthermore, sensory impairments and cataracts influence cognitive function partly via social participation. Our results have important theoretical and practical implications and suggests that early interventions for sensory impairments and eye diseases may improve the cognitive function of elderly people.

Association of age-related eye diseases with cognitive frailty in older adults: a population-based study

BACKGROUND

Age-related eye diseases and cognitive frailty (CF) are both important predictors of adverse health outcomes in older adults, however, little is known about their association.

AIMS

To demonstrate the association between age-related eye diseases and cognitive frailty in a population of Iranian older adults.

METHODS

In this cross-sectional, population-based study, we included 1136 individuals (female n = 514) aged 60 years and older (mean 68.8 ± 6.7 years) who participated in the second cycle of the Amirkola Health and Aging Project (AHAP) between 2016 and 2017. Cognitive function and frailty were evaluated based on Mini-Mental State Examination (MMSE) and the FRAIL scale respectively. Cognitive frailty was defined as coexistence of cognitive impairment (CI) and physical frailty (PF), excluding confirmed cases of dementia such as Alzheimer's disease. Cataract, diabetic retinopathy (DR), age-related macular degeneration (AMD), elevated intraocular pressure (IOP ≥ 21 mmHg) and glaucoma suspects (vertical cup to disc ratio (VCDR) ≥ 0.6) were diagnosed based on standardized grading protocols. Associations between eye diseases and cognitive frailty were evaluated through binary logistic regression analysis.

RESULTS

Overall, CI, PF and CF were observed in 257 (22.6%), 319 (28.1%) and 114 (10.0%) participants respectively. After adjusting for confounders and ophthalmic conditions, individuals with cataract were more likely to have CF (OR 1.66; p-value 0.043), while DR, AMD, elevated IOP and glaucoma suspects (OR 1.32, 1.62, 1.42, 1.36, respectively) were not significantly associated with CF. Furthermore, cataract was significantly associated with CI (OR 1.50; p-value 0.022), but not with frailty (OR 1.18; p-value 0.313).

CONCLUSION

Older adults with cataract were more likely to have cognitive frailty and cognitive impairment. This association demonstrates the implications of age-related eye diseases beyond ophthalmology and substantiates the need for further research involving cognitive frailty in the context of eye diseases and visual impairment.

Association of cataract extraction and the risk of dementia-A systematic review and meta-analysis

Objectives

This research aims to investigate if cataract extraction lowers the risk of all-cause dementia.

Methods

Original literature on cataract surgery associated with all-cause dementia as of November 27, 2022, was searched in several commonly used databases. Manual review was used to include eligible studies. Stata software (version 16) was used to perform statistical analysis on pertinent data. Publication bias can be precisely evaluated using funnel plots and Egger's test.

Results

In the meta-analysis of 4 cohort studies with 245,299 participants. Pooled analysis indicated that cataract surgery was linked to a lower incidence of all-cause dementia (OR = 0.77, 95%CI: 0.66-0.89; I²= 54.7%; P < 0.001). Cataract surgery was linked to a lower risk of AD (OR = 0.60, 95%CI: 0.35-1.02; I²= 60.2%; P < 0.001).

Conclusions

Cataract surgery is linked to a lower incidence of all-cause dementia and Alzheimer's disease. A cataract is a reversible visual impairment. Cataract surgery may be a protective factor against the onset of all-cause dementia and can reduce the economic and family burden caused by all-cause dementia worldwide. Given the restricted pool of included studies, our findings necessitate meticulous interpretation.

Systematic review registration

http://www.crd.york.ac.uk/prospero retrieve registration details by searching CRD4202379371.

Associations of concomitant retinopathy and depression with mortality in a nationally representative population

OBJECTIVE

To evaluate the interaction effects between retinopathy and depression on mortality risks in genral population and subpopulation with diabetes.

METHODS

Prospective analyses were conducted on data from the National Health and Nutrition Examination Surveys study. Associations of retinopathy, depression and their interaction with all-cause, cardiovascular disease (CVD)-specific, cancer-specific and other-specific mortality risk were estimated using Kaplan-Meier curves and multivariate Cox proportional hazards models.

RESULTS

Among 5367 participants, the weighted prevalence of retinopathy and depression was 9.6 % and 7.1 %, respectively. After a follow-up period of 12.1 years, 1295 deaths (17.3 %) occurred. Retinopathy was associated with an increased risk of all-cause (hazard ratio [HR]; 95 % confidence interval [CI]) (1.47; 1.27-1.71), CVD-specific (1.87; 1.45-2.41), and other-specific (1.43; 1.14-1.79) mortality. Similar relationship was observed between depression and all-cause mortality (1.24; 1.02-1.52). Retinopathy and depression had a positive multiplicative and additive interaction effect on all-cause (P_interaction = 0.015; relative excess risk of interaction [RERI] 1.30; 95 % CI 0.15-2.45) and CVD-specific mortality (P_interaction = 0.042; RERI 2.65; 95 % CI -0.12-5.42). Concomitant retinopathy and depression was more markedly associated with all-cause (2.86; 1.91-4.28), CVD-specific (4.70; 2.57-8.62), and other-specific mortality risks (2.18; 1.14-4.15) compared to those without retinopathy and depression. These associations were more pronounced in the diabetic participants.

CONCLUSIONS

The co-occurrence of retinopathy and depression increases the risk of all-cause and CVD-specific mortality among middle-aged and older adults in the United States, especially in population with diabetes. Focus on diabetic patients and active evaluation and intervention of retinopathy with depression may improve their quality of life and mortality outcomes.

Cataract, Cataract Surgery, and Risk of Incident Dementia: A Prospective Cohort Study of 300,823 Participants

BACKGROUND

Visual impairment and interventions to preserve vision may impact dementia risk. Thus, we aimed to explore the associations of cataract and cataract surgery with the risk of dementia.

METHODS

Prospective data from 300,823 individuals in the UK Biobank were used. We used multivariate Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals for associations, with healthy control subjects as a reference. The same method was used to explore the effects of surgery on dementia outcomes of patients with cataract. One-way analysis of variance was performed to examine the associations between cataract and brain morphometric measures.

RESULTS

After a mean follow-up of 8.4 years, 3226 individuals were diagnosed with dementia. The nonsurgical cataract group had increased risk of all-cause dementia (HR, 1.214; 95% CI, 1.012-1.456; p = .037) and Alzheimer's disease (HR, 1.479; 95% CI, 1.105-1.981; p = .009). However, there was no difference in dementia risk between the cataract surgery group and the healthy control group. Cataract surgery was associated with decreased risk of all-cause dementia (HR, 0.632; 95% CI, 0.421-0.947; p = .026) and Alzheimer's disease (HR, 0.399; 95% CI, 0.196-0.812; p = .011) compared with the nonsurgical group. Additionally, cataract was negatively associated with cortical volumes, aging-related subcortical volumes, and fractional anisotropy of white matter fibers.

CONCLUSIONS

Cataract patients who did not receive surgical treatment had an increased risk of dementia. However, cataract surgery could reverse the risk of dementia. Our findings on brain structures and pathways in patients with cataract also provided evidence for the mechanism. Reversible visual impairment, such as cataract, is a promising modifiable risk factor for dementia.

The Associations Between Cataracts and Alzheimer's Disease: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

The relationship between cataracts and Alzheimer's disease (AD) has been reported in recent observational studies. However, it is still unclear whether a causal effect of cataracts on AD or reverse causation exists.

OBJECTIVE

To explore the association between cataracts and AD genetically, we performed a bidirectional two-sample Mendelian randomization study.

METHODS

We obtained genetic instrumental variables related to cataracts and AD from recently published genome-wide association studies (GWASs). SNP-outcome associations for AD were obtained from a GWAS with 111,326 cases and 677,663 controls. SNP-outcome associations for cataracts were drawn from two sources: a GWAS with 67,844 cases and 517,399 controls and the FinnGen consortium (42,843 cases and 262,698 controls). Inverse variance weighted (IVW) was used as the primary method for Mendelian randomization (MR) analyses.

RESULTS

No genetic evidence suggested that cataracts were associated with the risk of AD (IVW odds ratio =1.04, 95% confidence interval: 0.98-1.10, p=0.199). In contrast, an effect of genetically determined AD on a decreased risk of cataract was observed with suggestive evidence (IVW odds ratio =0.96, 95% confidence interval: 0.93-0.99, p=0.004). However, this result might be distorted by survival bias.

CONCLUSION

Genetically determined cataracts were not related to AD, as demonstrated by our study. In contrast, there was suggestive evidence that AD might prevent cataract development, but there might be potential survival bias. To define the exact association between the two diseases, more prospective research and studies on the pathogenesis are needed.

The Association Between Diabetes Duration and Domain-Specific Cognitive Impairment: A Population-Based Study

BACKGROUND

Diabetes is a risk factor for cognitive impairment, and disease duration is associated with geriatric decline and functional disabilities.

OBJECTIVE

This study aimed to examine the association of diabetes duration with domain-specific cognitive impairment in elderly.

METHODS

A total of 3,142 participants from the National Health and Nutrition Examination Survey (NHANES) from the period between 2011 and 2014 were included. We assessed cognitive function using the Digit Symbol Substitution Test (DSST), the CERAD Word Learning (CERAD-WL) test, the CERAD Delayed Recall (CERAD-DR) test and animal fluency (AF) test.

RESULTS

After adjusting for age, sex, race/ethnicity, education level, and annual household income, we found that diabetes with a duration longer than 20 years were at 3.32-fold increased risk of DSST impairment (OR = 3.32, 95% CI: 1.95 to 5.67), 1.72-fold increased risk of CERAD-WL impairment (OR = 1.72, 95% CI: 1.13 to 2.62), and 1.76-fold increased risk of AF impairment (OR = 1.76, 95% CI: 1.23 to 2.53), compared with those with no diabetes. Associations were generally stronger in women than in men. Participants with diabetes, who were diagnosed at 50-59 years old were at increased risk of DSST impairment, CERAD-WL impairment, CERAD-DR impairment, and AF impairment per 5 years longer duration of diabetes.

CONCLUSION

Longer diabetes duration was associated with the increased risk of cognitive impairment, especially in processing speed and attention. The presence of chronic kidney disease was associated with the increased risk of DSST impairment.

Association between Sleep Duration and Grip Strength in U.S. Older Adults: An NHANES Analysis (2011-2014)

Handgrip strength has been shown an indispensable biomarker for older adults. Furthermore, the association between sleep duration and grip strength in special populations (e.g., type 2 diabetics) has been previously documented. However, the association between sleep duration and grip strength has been less studied in older adults and the dose-response relationship is unclear. Therefore, we drew 1881 participants aged 60 years and older from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 to explore their association and the dose-response relationship. Sleep duration was obtained through self-report. Grip strength data were obtained through a grip test using a handgrip dynamometer and divided into two categories: low grip strength and normal grip strength. Thus, dichotomized grip strength was used as a dependent variable. Poisson regression and restricted cubic spline were used for the main part of the analysis. We found that long sleep duration (≥9 h) was associated with a higher prevalence of low grip strength than the normal sleep duration (7-<9 h) group (IRR: 1.38, 95% CI: 1.12-1.69). Moreover, the gender-stratified analysis did not change the original results. This association was particularly pronounced and further strengthened among participants with normal weight (BMI < 25) (IRR: 2.30, 95% CI: 1.64-3.22) and participants aged 60-70 (IRR: 1.76, 95% CI: 1.40-2.22). In addition, with the increase in sleep duration, the multivariate-adjusted IRRs of low grip strength had a general downward trend at first, followed by a brief period of stability, and then presented an upward trend (p-value for non-linearity = 0.001). According to this study, we found that older adults who had long sleep duration had a higher risk of low grip strength. Muscle insulin utilization and muscle glucose metabolism are closely related to grip strength, so our research emphasizes the importance of maintaining normal sleep duration in older adults and suggests that older adults who sleep for a long period should pay more attention to their muscle health.