Association of body mass index with amnestic and non-amnestic mild cognitive impairment risk in elderly

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 role of pyroptosis in cognitive impairment

Cognitive impairment is a major global disease, manifests as a decline in cognitive functioning and endangers the health of the population worldwide. The incidence of cognitive impairment has increased rapidly with an increasingly aging population. Although the mechanisms of cognitive impairment have partly been elucidated with the development of molecular biological technology, treatment methods are very limited. As a unique form of programmed cell death, pyroptosis is highly pro-inflammatory and is closely associated with the incidence and progression of cognitive impairment. In this review, we discuss the molecular mechanisms of pyroptosis briefly and the research progress on the relationship between pyroptosis and cognitive impairment and its potential therapeutic values, to provide a reference for research in the field of cognitive impairment.

Associations of five obesity indicators with cognitive performance in 30,697 Taiwan Biobank participants

Background

Obesity adversely influences the central nervous system and cognitive functions. However, the relationship between various obesity indicators and cognitive performance remains controversial. It is unclear which obesity indicator is more relevant to cognitive impairment.

Methods

The Taiwan Biobank (TWB) administered the Chinese version of the Mini-Mental State Examination (MMSE) to 30,697 participants (12,094 males and 18,603 females) aged 60 to 70 years. A total of 3,454 (11.25%) individuals with MMSE < = 24 were classified as having poor cognitive performance. This cross-sectional study investigates the associations of five obesity indicators with cognitive performance. Five separate logistic regression models were fitted for males and another five for females. Covariates adjusted in all models included age, smoking status, drinking status, regular exercise, chronic disease status (diabetes, cardiovascular diseases, heart diseases, stroke, or Parkinson’s disease), depression status, blood pressure level, total cholesterol, fasting glucose, and educational attainment. The five obesity indicators included body mass index (BMI), body fat percentage (BFP), waist circumference (WC), hip circumference (HC), and waist-hip ratio (WHR).

Results

Abdominal obesity defined by WHR was significantly associated with poor cognitive performance. Male WHR > = 0.90 had a higher risk of poor cognitive performance than male WHR < 0.90 (odds ratio [OR] = 1.233; p = 0.007); female WHR > = 0.85 had an increased risk of poor cognitive performance compared with female WHR < 0.85 (OR = 1.221; p = 3.9E-4). HC and general obesity (defined by BMI and BFP) were not significantly associated with cognitive performance.

Conclusion

The results consistently agreed that preventing abdominal obesity is associated with better cognitive performance in both males and females.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03457-x.

Favourable Lifestyle Protects Cognitive Function in Older Adults With High Genetic Risk of Obesity: A Prospective Cohort Study

The relationship between body mass index (BMI) and cognitive impairment remains controversial, especially in older people. This study aims to confirm the association of phenotypic and genetic obesity with cognitive impairment and the benefits of adhering to a healthy lifestyle. This prospective study included 10,798 participants (aged ≥ 50 years) with normal cognitive function from the Health and Retirement Study in the United States. Participants were divided into low (lowest quintile), intermediate (quintiles 2–4), and high (highest quintile) groups according to their polygenic risk score (PRS) for BMI. The risk of cognitive impairment was estimated using Cox proportional hazard models. Higher PRS for BMI was associated with an increased risk, whereas phenotypic obesity was related to a decreased risk of cognitive impairment. Never smoking, moderate drinking, and active physical activity were considered favourable and associated with a lower risk of cognitive impairment compared with current smoking, never drinking, and inactive, respectively. A favourable lifestyle was associated with a low risk of cognitive impairment, even in subjects with low BMI and high PRS for BMI. This study suggest that regardless of obesity status, including phenotypic and genetic, adhering to a favourable lifestyle is beneficial to cognitive function.

Screening for mild cognitive impairment in people with obesity: a systematic review

OBJECTIVE

Recent evidence demonstrates that obesity is associated with developing cognitive impairment. However, evidence related to the assessment of mild cognitive impairment (MCI) in people with obesity is limited. Therefore, this systematic review aimed to examine evidence concerning the screening of MCI in people with obesity from the general population.

METHOD

We conducted a systematic search of CINHAL, EMBASE, MEDLINE, PsycINFO and PubMed electronic databases for observational studies to assess MCI in people with obesity from the general population. PRISMA guideline was followed. The articles published from January 2011 to July 2021 were included.

RESULTS

Database search found 3104 sources. After the screening process, two articles from China and Egypt were included. The main age groups assessed were middle-aged adulthood and older adulthood. There were no studies undertaken in young adults or across the life span. Obesity was assessed by body mass index. MCI was assessed by cognitive screening tools; Mini-mental State Examination and Addenbrooke's Cognitive Examination. The prevalence of MCI in people with obesity was 18.5 % and 42.9 % in Chinese and Egyptian studies, respectively. Only one study supported a positive association between MCI and obesity.

CONCLUSIONS

Limited studies were found on screening MCI in people with obesity in the general population. The available evidence was not adequate to explain the overall prevalence, possible associations, and the best tool for assessing MCI in people with obesity. Expanding screening studies for MCI in people with obesity in the general population is essential.

Urban-rural disparities in mild cognitive impairment and its functional subtypes among community-dwelling older residents in central China

BACKGROUND

Substantial variations in the prevalence of mild cognitive impairment (MCI) and its subtypes have been reported, although mostly in geographically defined developed countries and regions. Less is known about MCI and its subtypes in rural areas of less developed central China.

AIMS

The study aimed to compare the prevalence of MCI and its subtypes in residents aged 65 years or older in urban and rural areas of Hubei Province, China.

METHODS

Participants aged 65 years or older were recruited between 2018 and 2019. Inperson structured interviews and clinical and neuropsychological assessments were performed at city health community centres and township hospitals.

RESULTS

Among 2644 participants without dementia, 735 had MCI, resulting in a prevalence of 27.8% for total MCI, 20.9% for amnestic MCI (aMCI) and 6.9% for non-amnestic MCI (naMCI). The prevalence of MCI in urban and rural areas was 20.2% and 44.1%, respectively. After adjusting for demographic factors, the prevalence of total MCI, aMCI and naMCI differed significantly between rural and urban areas (adjusted odds ratio (OR) 2.10, 1.44 and 3.76, respectively). Subgroup analysis revealed an association between rural socioeconomic and lifestyle disadvantage and MCI and its subtypes.

CONCLUSIONS

Our findings suggest that the prevalence of MCI among urban residents in central China is consistent with that in other metropolis areas, such as Shanghai, but the prevalence in rural areas is twice that in urban areas. Prospective studies and dementia prevention in China should focus on rural areas.

Exogenous IGF-1 improves tau pathology and neuronal pyroptosis in high-fat diet mice with cognitive dysfunction

Insulin-like growth factor-1 (IGF-1) improves obesity-induced cognitive dysfunction, but its mechanism is not fully clarified. The aim of the study was to reveal whether IGF-1 treated cognitive dysfunction by improving tau pathology and neuronal pyroptosis in high-fat diet mice. During in vitro experiment, C57BL/6J mice were fed with high-fat diet, and were treated with PEG-IGF-1, IGF-1 receptor blocker AXL1717, HO-1 blocker Znpp IX or their combinations. Cognitive function was evaluated using Morris water maze. Expression of Nrf2, HO-1, p-tau, NLRP3, caspase-1 and IL-1β in hippocampus was determined using western blotting. Pyroptosis rate in hippocampus was measured using flow cytometry. During in vivo experiment, HN-h cells were treated with palmitic acid, pyroptosis blocker nonecrosulfonamide or their combinations. The expression of the proteins and rate of pyroptosis were also measured using western blotting and flow cytometry. During in vitro experiment, high-fat diet mice showed cognitive dysfunction, significant hyperphosphorylation of tau protein and neuronal pyroptosis in hippocampus compared with the sham mice. After exogenous IGF-1 treatment, these abnormalities were reversed and Nrf2/HO-1 signaling pathway was activated. Inhibition of the signaling pathway using AXL1717 or Znpp IX re-deteriorated cognitive function, tau pathology and neuronal pyroptosis in hippocampus. During in vivo experiment, inhibition of pyroptosis using nonecrosulfonamide improved tau pathology in palmitic acid-treated HN-h cells. Exogenous IGF-1 improved tau pathology induced by high-fat diet through inhibition of neuronal pyroptosis and activation of Nrf2/HO-1 signaling pathway.

Associations between dietary fatty acid patterns and cognitive function in the Hispanic Community Health Study/Study of Latinos

Our objective was to quantify the cross-sectional associations between dietary fatty acid (DFA) patterns and cognitive function among Hispanic/Latino adults. This study included data from 8,942 participants of the Hispanic Community Health Study/Study of Latinos, a population-based cohort study (weighted age 56.2 y and proportion female 55.2%). The NCI (National Cancer Institute) method was used to estimate dietary intake from two 24-hr recalls. We derived DFA patterns using principal components analysis with 26 fatty acid and total plant and animal monounsaturated fatty acid (MUFA) input variables. Global cognitive function was calculated as the average z-score of 4 neurocognitive tests. Survey linear regression models included multiple potential confounders such as age, sex, education, depressive symptoms, physical activity, energy intake, and cardiovascular disease. DFA patterns were characterized by consumption of long-chain saturated fatty acids (SFA), animal-based MUFA, and trans fatty acids (Factor 1); short to medium-chain SFA (Factor 2); very-long-chain omega-3 polyunsaturated fatty acids (PUFA) (Factor 3); very-long-chain SFA and plant-based MUFA and PUFA (Factor 4). Factor 2 was associated with greater scores for global cognitive function (β=0.037 ± 0.012) and the Digit Symbol Substitution (DSS) (β=0.56±0.17), Brief Spanish English Verbal Learning-Sum (B-SEVLT) (β=0.23 ± 0.11), and B-SEVLT-Recall (β=0.11 ± 0.05) tests (P<0.05 for all). Factors 1 (β=0.04 ± 0.01) and 4 (β=0.70 ± 0.18) were associated with the DSS test (P<0.05 for all). Consumption of short to medium-chain SFA may be associated with higher cognitive function among U.S.-residing Hispanic/Latino adults. Prospective studies are necessary to confirm these findings.

Body mass index and mild cognitive impairment among rural older adults in China: the moderating roles of gender and age

BACKGROUND

Evidence concerning the association between body mass index (BMI) and cognitive function among older people is inconsistent. This study aimed to investigate gender and age as moderators in association between BMI and mild cognitive impairment (MCI) among rural older adults.

METHODS

Data were derived from the 2019 Health Service for Rural Elderly Families Survey in Shandong, China. In total, 3242 people aged 60 years and above were included in the analysis. Multilevel mixed-effects logistic regression was used to examine the moderating roles of gender and age, then further to explore the relationship between BMI and MCI.

RESULTS

There were 601 (18.5%) participants with MCI. Compared with normal BMI group, low BMI group had a higher risk of MCI among older people [adjusted odds ratio (aOR) = 2.08, 95% confidence interval (CI): 1.26-3.44], women (aOR = 2.06, 95% CI: 1.35-3.12), or the older elderly aged ≥75 years old (aOR = 3.20, 95% CI: 1.34-7.45). This effect remained statistically significant among older women (aOR = 3.38, 95% CI: 1.69-6.73). Among older men, elevated BMI group had a higher risk of MCI (aOR = 2.32, 95% CI: 1.17-4.61) than normal BMI group.

CONCLUSIONS

Gender and age moderated the association between BMI and MCI among Chinese rural older adults. Older women with low BMI were more likely to have MCI, but older men with elevated BMI were more likely to have MCI. These findings suggest rural community managers strengthen the health management by grouping the weight of older people to prevent the risk of dementia.

Factors Predicting the Onset of Amnestic Mild Cognitive Impairment or Alzheimer's Dementia in Persons With Subjective Cognitive Decline

The objective of the current retrospective cohort study was to identify vascular and/or neuropsychiatric risk factors predicting clinical progression in persons with subjective cognitive decline (SCD). Information on 1,525 persons with SCD (mean age = 73.8 [SD = 8.1] years) was obtained from the National Alzheimer's Coordinating Center. Clinical progression occurred from SCD to either amnestic mild cognitive impairment or Alzheimer's dementia over an average of 4.7 (SD = 2.9) years. Stepwise Cox regression was used. Compared to obesity (hazard ratio [HR] = 0.59) in the univariate unadjusted model, obesity (HR = 0.64), current smoking (HR = 2.02), and depressive symptoms (HR = 1.35) were significant after adjusting for covariates in the univariate model. In the multivariate adjusted model, obesity (HR = 0.64), current smoking (HR = 2.04), and depressive symptoms (HR = 1.36) remained significant predictors. Interventions should be designed to minimize transition by managing smoking and depressive symptoms. Further research is required for associations between obesity and clinical progression to test the hypothesis of obesity paradox. [Journal of Gerontological Nursing, 46(8), 28-36.].

Fish Intake May Affect Brain Structure and Improve Cognitive Ability in Healthy People

As the population ages worldwide, the prevalence of cognitive disorders including mild cognitive impairment (MCI) is increasing. MCI appears in 10–20% of adults aged 65 years and older and is generally referred to as an intermediate stage between normal cognitive aging and dementia. To develop timely prevention and early treatment strategies by identifying biological factors, we investigated the relationship between dietary consumption of fish, brain structure, and MCI in cognitively normal subjects. The brain structure was assessed using neuroimaging-derived measures including the “gray-matter brain healthcare quotient (GM-BHQ)” and “fractional-anisotropy brain healthcare quotient (FA-BHQ),” which are approved as the international standard (H.861.1) by the International Telecommunication Union Telecommunication Standardization Sector. Dietary consumption of fish was calculated using the brief self-administered diet history questionnaire (BDHQ), and MCI was assessed using the Memory Performance Index (MPI) of MCI screening method (MCI Screen). This study showed that fish intake was positively associated with both FA-BHQ and MPI, and FA-BHQ was more strongly associated with MPI than fish intake. Our findings are in line with those in previous studies, but our study further indicates that the condition of the whole brain integrity measured by the FA-BHQ may mediate the relationship between fish intake and MCI prevention in healthy people. In other words, FA-BHQ may be used to identify people at high risk of MCI to provide the appropriate intervention.

Visceral adiposity index as a tool for cardiometabolic risk in obese older women

OBJECTIVE: To correlate anthropometric measurements, lipid profile, cardiorespiratory fitness, and visceral adiposity index (VAI) in sedentary obese older women. METHODS: Twenty-seven insufficiently active and overweight older women were included in this cross-sectional study. We evaluated their anthropometric profile (body weight and stature, body mass index, waist and hip circumferences) and body composition (fat mass, body fat percentage, and musculoskeletal mass). Venous blood samples were analyzed for high and low-density lipoproteins (HDL-c and LDL-c), triglycerides (TG), and the LDL/HDL ratio. Peak oxygen uptake (VO2 peak) was measured using an adapted Bruce test using direct spirometry. We tested data normality and applied Pearson’s correlation, assuming a p ≤ 0.05. RESULS: The following correlations were observed: VAI and HDL (r = -0.53); VAI and LDL (r = 0.35); VAI and TG (r = 0.86); VAI and TG/HDL (r = 0.99) and VAI and VO2 peak (r = -0.55), with p < 0.01 for all analyses. CONCLUSION: The findings suggested that VAI may be used as a tool to assess cardiometabolic risk in obese older women. Future studies should evaluate the applicability of VAI as a cardiometabolic risk factor indicator in older adults.

Establishment of a Risk Prediction Model for Mild Cognitive Impairment among Elderly Chinese

BACKGROUND

Mild cognitive impairment (MCI) is a transitional stage of cognitive function between normal aging and dementia. Substantial variations in the prevalence of MCI in different countries have been studied including China. In this study, we established a prediction system to assess the risk of MCI among the elderly in China.

METHODS

The Rothman-Keller model was conducted on the basis of the risk factors of MCI obtained by the combined results of a meta-analysis. The accuracy of the model was verified using actual population data.

RESULTS

A total of 1826 subjects as a verification set were enrolled in this study in February 2019. There were statistically significant differences in the combined results of 10 risk factors including hypertension, diabetes, educational level, hyperlipidemia, smoking, physical exercise, living alone, stroke, drinking and heart disease (P<0.05). The area under the curve (AUC) of the actual data and the predictive results of this model was 0.859 (95%CI: 0.812-0.906, P<0.05), the sensitivity was 86.6% and the specificity was 76.5%.

CONCLUSIONS

This model performs an effective prediction that may be applied to the primary prevention for patients with MCI, helping to reduce the risk of MCI.

Relationship between normal weight obesity and mild cognitive impairment is reflected in cognitive-related genes in human peripheral blood mononuclear cells

AIM

Obesity contributes to the development of mild cognitive impairment, but the potential role of normal weight obesity in this disease has not been explored in humans. The aim of the study was to reveal the relationship between normal weight obesity and mild cognitive impairment in elderly individuals.

METHODS

This study consisted of 360 patients with amnestic mild cognitive impairment and 360 cognitively normal controls. Normal weight obesity was defined as having metabolic syndrome but a normal weight. Metabolic health meant having no metabolic syndrome. Reverse transcription quantitative real-time polymerase chain reaction was adopted to measure the messenger RNA expression of four cognitive-related genes (amyloid precursor protein, cyclic adenosine monophosphate-responsive element-binding protein 1, sortilin-related receptor 1, and synapsin I) in peripheral blood mononuclear cells.

RESULTS

Normal weight obesity was related to a higher risk of amnestic mild cognitive impairment (odds ratio = 3.14, 95% confidence interval: 2.13-4.60). In the patients, the expression of each gene in the peripheral blood mononuclear cells was linearly related to Mini-Mental State Examination and Montreal Cognitive Assessment scores (P < 0.05). The expression of these genes in the patients with metabolic health deviated from the normal levels found in the controls (P < 0.05), and the deviations were more significant in the patients with normal weight obesity (P < 0.05).

CONCLUSION

Normal weight obesity may be a potential risk factor for amnestic mild cognitive impairment in elderly. This relationship was reflected in the abnormal expression of several cognitive-related genes in peripheral blood mononuclear cells.

Non-communicable Diseases and Cognitive Impairment: Pathways and Shared Behavioral Risk Factors Among Older Chinese

Population aging has brought about a number of challenges to public health and primary health care systems due to increases in the prevalence of non-communicable diseases (NCDs). As a country with one of the largest populations globally, China is confronting a rising number of chronic NCDs including cardiometabolic related conditions. This mini-review investigates the link between NCDs and cognitive impairment through common risk factors. Identifying risk factors is important for the prevention and management of these chronic conditions. In addition, this review also identifies the role of primary health care services in reducing behavioral risk factors for NCDs and cognitive impairment. Addressing shared determinants and pathways is important in the design of public health interventions and primary health care services in China. Monitoring and management of NCD biomarkers and behavioral risk factors may also be beneficial for cognitive health among older Chinese.

Effects of sleep-disordered breathing and hypertension on cognitive function in elderly adults

Purpose: The prevalence of sleep-disordered breathing (SDB) increases with aging. SDB is a risk of hypertension, and both might lead to cognitive decline. However, the role of SDB and hypertension on the pathogenesis of age-related cognitive decline remains unclear. We examined the effects of these two diseases on cognitive function in elderly adults.Methods: Fifty-two elderly individuals (mean age, 69.6 ± 4.0 years) free from impairment in daily living activities participated in this study. Apnea/hypopnea index (AHI) and minimum oxygen saturation (SpO₂) were assessed using a portable home monitoring device. We evaluated excessive daytime sleepiness with the Epworth sleepiness scale (ESS). Cognitive performance was assessed using the Wisconsin card sorting test (WCST), continuous performance test-Identical pairs (CPT-IP), and N-back task. Hypertension and diabetes mellitus were evaluated via questionnaire and blood pressure value.Results: The WCST category achievement was significantly lower in participants with minimum SpO₂ <90% than those with minimum SpO₂ ≥90%. The percentage of correct answer on the 0- and 1-back tasks was significantly lower in the hypertensives than normotensives. Minimum SpO₂ was correlated with category achievement on the WCST. Multiple regression analysis including age, sex, body mass index, AHI, minimum SpO₂, ESS, hypertension, and diabetes mellitus revealed that hypertension was the most significant factor for percentage correct answers on the 0- and 1-back tasks. There were no significant correlations between body mass index, ESS or diabetes mellitus and the parameters of WCST, CPT-IP, or N-back tasks.Conclusion: In elderly adults, nocturnal hypoxia and hypertension had a negative effect on cognitive function.

Mild cognitive impairment: A concept analysis

AIM

To clarify the concept of mild cognitive impairment (MCI) and identify its attributes to enhance understanding of its implications for nursing practice and research.

BACKGROUND

MCI is a concept that has evolved, thus clarification of this concept is essential for the advancement of nursing science.

DESIGN

Walker and Avant's eight steps of concept analysis strategy was used.

DATA SOURCE

Manuals of mental disorders and databases such as PubMed, Springer, PsychINFO, Cumulative Index to Nursing and Allied Health Literature, and Education Resources Information Center (ERIC) from 1982 to 2018.

REVIEW METHODS

A literature search was conducted using keywords such as "mild," "cognitive," "impairment," and "deterioration."

RESULTS

The concept of MCI is defined as the transitional state between cognitive state normal for age and the early manifestation of dementia states. It is characterized by the presence of objective and subjective evidence of impairment in one or multiple cognitive domains, independence in daily activities, can be reversible, and is a risk factor for dementia.

CONCLUSIONS

Clarification of MCI serves as a framework for identification, treatment, and interventions that may support healthy aging in older adults.

Body mass index, waist-to-hip ratio and cognitive function among Chinese elderly: a cross-sectional study

OBJECTIVES

To investigate the associations between body mass index (BMI), waist-to-hip ratio (WHR) and cognitive function among Chinese elderly.

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

Data were obtained from the baseline survey of a community-based cohort in Zhejiang Province, and 9326 persons aged 60 years and older were enrolled.

PRIMARY OUTCOME MEASURES

We investigated the association between BMI and cognition, and then explored the association between WHR and cognition across different quartiles of BMI.

RESULTS

A sample of 9087 persons was used in this study, including 4375 men and 4712 women. Higher WHR increased cognitive impairment risk in those with BMI >25.3 kg/m² (OR (per 0.1 increase) 1.39; 95% CI 1.13 to 1.70). No statistically significant association was found in other BMI categories.

CONCLUSIONS

Higher WHR could increase the risk of cognitive impairment among elderly with BMI >25.3 kg/m². Our results suggest that it could be of benefit to the elderly with high BMI to control WHR.