The prevalence of mild cognitive impairment in type 2 diabetes mellitus patients: a systematic review and meta-analysis

True or false? Alzheimer's disease is type 3 diabetes: Evidences from bench to bedside

Globally, Alzheimer's disease (AD) is the most widespread chronic neurodegenerative disorder, leading to cognitive impairment, such as aphasia and agnosia, as well as mental symptoms, like behavioral abnormalities, that place a heavy psychological and financial burden on the families of the afflicted. Unfortunately, no particular medications exist to treat AD, as the current treatments only impede its progression.The link between AD and type 2 diabetes (T2D) has been increasingly revealed by research; the danger of developing both AD and T2D rises exponentially with age, with T2D being especially prone to AD. This has propelled researchers to investigate the mechanism(s) underlying this connection. A critical review of the relationship between insulin resistance, Aβ, oxidative stress, mitochondrial hypothesis, abnormal phosphorylation of Tau protein, inflammatory response, high blood glucose levels, neurotransmitters and signaling pathways, vascular issues in AD and diabetes, and the similarities between the two diseases, is presented in this review. Grasping the essential mechanisms behind this detrimental interaction may offer chances to devise successful therapeutic strategies.

The effect of multi-component exercise on cognition function in patients with diabetes: A systematic review and meta-analysis

BACKGROUND

This meta-analysis investigated the influence of exercise on cognitive function in people living with diabetes.

METHODS

Stringent criteria for literature inclusion and exclusion were defined. Searches were conducted across four English databases to gather randomized controlled trials investigating exercise interventions for cognitive function in people living with diabetes. Outcome indicators from 1193 subjects across 12 articles were analyzed using RevMan 5.4 software.

RESULTS

Exercise intervention demonstrated the ability to mitigate cognitive decline in people living with diabetes, with a combined effect size (standardized mean difference) of 0.91, 95% CI: 0.28, 1.54, P < 0.00001. The intervention effect showed significant modulation by intervention content (I2 = 95%), intervention duration (I2 = 95%), intervention frequency (I2 = 95%), and intervention cycle (I2 = 96%). Among these factors, multi-component exercise, sessions >40 minutes, exercise frequency >4 times per week, and sustained exercise for >6 months were paramount, all with P < 0.05.

CONCLUSION

Exercise intervention emerges as a viable strategy for delaying cognitive decline in people living with diabetes. Its efficacy is subject to modulation by various variables. Optimal intervention includes multi-component exercise, individual sessions lasting 40-60 minutes, exercising >4 times a week, and continuous exercise for over 6 months.

BMI, weight change, appetite reduction and cognitive impairment of elderly patients with diabetes

Body weight is related to both diabetes and cognitive impairment; however, the associations between body mass index (BMI) and cognitive impairment have been reported less frequently among diabetes patients. A total of 1355 patients with type 2 diabetes aged ≥ 60 years were included in this study. The Montreal Cognitive Assessment (MoCA) was administered to assess participants' cognitive status. We collected self-reported body weight, weight loss and appetite loss data using questionnaires. Associations between body weight status (in childhood, midlife age, and late life), weight loss, appetite changes and cognitive impairment were explored using logistic regression. Among the participants, 41.7% exhibited cognitive impairment. Overweight in childhood and late life was associated with cognitive impairment among diabetes patients (OR 2.63, 95% CI 1.52-4.55; OR 1.32, 95% CI 1.03-1.69). Diabetes patients with cognitive impairment were more likely to report a body weight decline and appetite reduction in the past three months (OR 4.18, 95% CI 2.61-6.71; OR 4.41, 95% CI 2.67-7.29). Higher BMI, weight loss, and appetite reduction were positively correlated with cognitive impairment. Given the risk of cognitive impairment, we suggest that body weight and BMI decline should be monitored in patients with diabetes.

Gender differences in the association between physical activity and cognitive subdomains among elders with type 2 diabetes and mild cognitive impairment: a cross-sectional study

OBJECTIVES

The objective of this study was to evaluate the gender differences in the correlation between physical activity (PA) and cognitive subdomains in elderly individuals with type 2 diabetes (T2D) and mild cognitive impairment (MCI).

DESIGN

Cross-sectional study.

SETTING

The research was carried out in communities located in Fuzhou, Fujian Province and Beijing Municipality.

PARTICIPANTS

Community-dwelling elders with T2D and MCI aged 60 years or older were eligible for this study.

PRIMARY OUTCOME MEASURES AND ANALYSES

The weekly PA score was assessed using the International Physical Activity Questionnaire (IPAQ). The cognitive subdomains were evaluated through a battery of cognitive assessments, including the Rey Auditory Verbal Learning Test (RAVLT), Trail Making Test Part B, Digit Symbol Substitution Test (DSST) and the Stroop Color-Word Test (SCWT). Multiple linear regression models were employed to examine the association between PA and cognitive subdomains in both male and female individuals.

RESULTS

In older men, higher total IPAQ score was positively correlated with higher RAVLT (P=0.011) and SCWT (P=0.049). There was a significant interaction between the total PA score and gender in relation to RAVLT (P=0.008) and SCWT (P=0.027). Moreover, there was a positive correlation between moderate-vigorous PA level and RAVLT in older men (P=0.007). Additionally, a positive correlation was found between moderate-vigorous PA level and DSST in older women (P=0.038).

CONCLUSION

In older individuals with T2D and MCI, the association between PA and cognitive subdomains differs between men and women. This discrepancy may impact the customisation of exercise recommendations.

Unraveling the cognitive implications among individuals with co-occurring chronic periodontitis and type 2 diabetes mellitus: a cross-sectional study

OBJECTIVES

Chronic periodontitis and type 2 diabetes mellitus (T2DM) are associated with cognitive decline when examined individually. To gain deeper insight into the combined effects of these conditions on cognitive decline, the present study aimed to examine the cognitive status of individuals with co-occurring T2DM and chronic periodontitis.

METHODS

We recruited 220 participants categorized into four groups: Group I, healthy subjects; Group II, individuals with chronic periodontitis; Group III, individuals with T2DM; and Group IV, individuals with both T2DM and chronic periodontitis. Medical histories were recorded for all participants, followed by periodontal examination and evaluation of cognitive status using the Montreal Cognitive Assessment (MoCA) scale. Finger dexterity was assessed using the nine-hole peg test.

RESULTS

A statistically significant increase in the proportion of mild cognitive impairment (MCI) was observed between groups I and IV (p<0.001). Logistic regression analysis revealed that, among the parameters assessed in this study, the adjusted odds ratio (OR) was significant for age, finger dexterity scores, and co-occurrence of T2DM and periodontitis.

CONCLUSIONS

The findings of this study suggest that the co-occurrence of chronic periodontitis and T2DM can have a detrimental effect on the cognitive abilities of an individual. Subsequent research should include longitudinal monitoring of the cognitive status in patients with concurrent conditions during treatment to gain deeper prognostic insights into the relationship between these co-occurring conditions and cognitive decline.

Validity of Montreal Cognitive Assessment to Detect Cognitive Impairment in Individuals with Type 2 Diabetes

INTRODUCTION

Guidelines recommend screening older people (> 60-65 years) with type 2 diabetes (T2D) for cognitive impairment, as it has implications in the management of diabetes. The Montreal Cognitive Assessment (MoCA) is a sensitive test for the detection of mild cognitive impairment (MCI) in the general population, but its validity in T2D has not been established.

METHODS

We administered MoCA to patients with T2D (age ≥ 60 years) and controls (no T2D), along with a culturally validated neuropsychological battery and functional activity questionnaire. MCI was defined as performance in one or more cognitive domains ≥ 1.0 SD below the control group (on two tests representing a cognitive domain), with preserved functional activities. The discriminant validity of MoCA for the diagnosis of MCI at different cut-offs was ascertained.

RESULTS

We enrolled 267 patients with T2D and 120 controls; 39% of the participants with T2D met the diagnostic criteria for MCI on detailed neuropsychological testing. At the recommended cut-off on MoCA (< 26), the sensitivity (94.2%) was high, but the specificity was quite low (29.5%). The cut-off score of < 23 showed an optimal trade-off between sensitivity (69.2%), specificity (71.8%), and diagnostic accuracy (70.8%). The cut-off of < 21 exhibited the highest diagnostic accuracy (74.9%) with an excellent specificity (91.4%), a good positive and negative predictive value (78.5% and 73.7%, respectively).

CONCLUSIONS

The recommended screening cut-off point on MoCA of < 26 has a suboptimal specificity and may increase the referral burden in memory clinics. A lower cut-off of < 21 on MoCA maximizes the diagnostic accuracy. Interactive Visual Abstract available for this article.

Diabetes mellitus and Alzheimer's disease: Vacuolar adenosine triphosphatase as a potential link

Globally, the incidence of diabetes mellitus (DM) and Alzheimer's disease (AD) is increasing year by year, causing a huge economic and social burden, and their pathogenesis and aetiology have been proven to have a certain correlation. In recent years, more and more studies have shown that vacuolar adenosine triphosphatases (v-ATPases) in eukaryotes, which are biomolecules regulating lysosomal acidification and glycolipid metabolism, play a key role in DM and AD. This article describes the role of v-ATPase in DM and AD, including its role in glycolysis, insulin secretion and insulin resistance (IR), as well as its relationship with lysosomal acidification, autophagy and β-amyloid (Aβ). In DM, v-ATPase is involved in the regulation of glucose metabolism and IR. v-ATPase is closely related to glycolysis. On the one hand, v-ATPase affects the rate of glycolysis by affecting the secretion of insulin and changing the activities of key glycolytic enzymes hexokinase (HK) and phosphofructokinase 1 (PFK-1). On the other hand, glucose is the main regulator of this enzyme, and the assembly and activity of v-ATPase depend on glucose, and glucose depletion will lead to its decomposition and inactivation. In addition, v-ATPase can also regulate free fatty acids, thereby improving IR. In AD, v-ATPase can not only improve the abnormal brain energy metabolism by affecting lysosomal acidification and autophagy but also change the deposition of Aβ by affecting the production and degradation of Aβ. Therefore, v-ATPase may be the bridge between DM and AD.

Risk factors and metabolomics of mild cognitive impairment in type 2 diabetes mellitus

Objective: This study aimed to explore the risk factors, metabolic characteristics, and potential biomarkers of mild cognitive impairment in type 2 diabetes mellitus (T2DM-MCI) and to provide potential evidence for the diagnosis, prevention, and treatment of mild cognitive impairment (MCI) in patients with type 2 diabetes mellitus (T2DM). Methods: A total of 103 patients with T2DM were recruited from the Endocrinology Department of The Second Affiliated Hospital of Dalian Medical University for inclusion in the study. The Montreal Cognitive Assessment (MoCA) was utilized to evaluate the cognitive functioning of all patients. Among them, 50 patients were categorized into the T2DM-MCI group (MoCA score < 26 points), while 53 subjects were classified into the T2DM without cognitive impairment (T2DM-NCI) group (MoCA score ≥ 26 points). Serum samples were collected from the subjects, and metabolomics profiling data were generated by Ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). These groups were analyzed to investigate the differences in expression of small molecule metabolites, metabolic pathways, and potential specific biomarkers. Results: Comparison between the T2DM-MCI group and T2DM-NCI group revealed significant differences in years of education, history of insulin application, insulin resistance index, insulin-like growth factor-binding protein-3 (IGFBP-3), and creatinine levels. Further binary logistic regression analysis of the variables indicated that low educational level and low serum IGFBP-3 were independent risk factor for T2DM-MCI. Metabolomics analysis revealed that differential expression of 10 metabolites between the T2DM-MCI group and T2DM-NCI group (p < 0.05 and FDR<0.05, VIP>1.5). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway analysis revealed that fatty acid degradation was the most significant pathway. Receiver operating characteristic (ROC) analysis shows that lysophosphatidylcholine (LPC) 18:0 exhibited greater diagnostic efficiency. Conclusion: This study revealed that a shorter duration of education and lower serum IGFBP-3 levels are independent risk factors for T2DM-MCI. Serum metabolites were found to be altered in both T2DM-MCI and T2DM-NCI groups. T2DM patients with or without MCI can be distinguished by LPC 18:0. Abnormal lipid metabolism plays a significant role in the development of MCI in T2DM patients.

A new nomogram model for the individualized prediction of mild cognitive impairment in elderly patients with type 2 diabetes mellitus

Background

A high risk of developing mild cognitive impairment (MCI) is faced by elderly patients with type 2 diabetes mellitus (T2DM). In this study, independent risk factors for MCI in elderly patients with T2DM were investigated, and an individualized nomogram model was developed.

Methods

In this study, clinical data of elderly patients with T2DM admitted to the endocrine ward of the hospital from November 2021 to March 2023 were collected to evaluate cognitive function using the Montreal Cognitive Assessment scale. To screen the independent risk factors for MCI in elderly patients with T2DM, a logistic multifactorial regression model was employed. In addition, a nomogram to detect MCI was developed based on the findings of logistic multifactorial regression analysis. Furthermore, the accuracy of the prediction model was evaluated using calibration and receiver operating characteristic curves. Finally, decision curve analysis was used to evaluate the clinical utility of the nomogram.

Results

In this study, 306 patients were included. Among them, 186 patients were identified as having MCI. The results of multivariate logistic regression analysis demonstrated that educational level, duration of diabetes, depression, glycated hemoglobin, walking speed, and sedentary duration were independently correlated with MCI, and correlation analyses showed which influencing factors were significantly correlated with cognitive function (p <0.05). The nomogram based on these factors had an area under the curve of 0.893 (95%CI:0.856-0.930)(p <0.05), and the sensitivity and specificity were 0.785 and 0.850, respectively. An adequate fit of the nomogram in the predictive value was demonstrated by the calibration plot.

Conclusions

The nomogram developed in this study exhibits high accuracy in predicting the occurrence of cognitive dysfunction in elderly patients with T2DM, thereby offering a clinical basis for detecting MCI in patients with T2DM.

A Nomogram Including Total Cerebral Small Vessel Disease Burden Score for Predicting Mild Vascular Cognitive Impairment in Patients with Type 2 Diabetes Mellitus

Background

Total cerebral small vessel disease (CSVD) burden score is an important predictor of vascular cognitive impairment (VCI). However, few predictive models of VCI in type 2 diabetes mellitus (T2DM) patients have included the total CSVD burden score, especially in the early stage of VCI.

Objective

To develop and validate a nomogram that includes the total CSVD burden score to predict mild VCI in patients with T2DM.

Methods

A total of 322 eligible participants with T2DM who were divided into mild and normal cognitive groups were enrolled in this retrospective study. Demographic data, laboratory data and imaging markers of CSVD were collected. The total CSVD burden score was calculated by combining the different CSVD markers. Step-backward multivariable logistic regression analysis with the Akaike information criterion was applied to select significant predictors and develop a best-fit predictive nomogram. The performance of the nomogram was assessed in terms of discriminative ability, calibrated ability, and clinical usefulness.

Results

The nomogram model consisted of five variables: age, education, hemoglobin A1c level, serum homocysteine level, and total CSVD burden score. A nomogram with these variables showed good discriminative ability (area under the receiver operating characteristic curve was 0.801 in internal verification). In addition, the Hosmer-Lemeshow test (χ2 =9.226, P=0.417) and bootstrap-corrected calibration plot indicated that the nomogram had good calibration. The Brier score of the predictive model was 0.178. Decision curve analysis demonstrated that when the threshold probability ranged between 16% and 98%, the use of the nomogram to predict mild VCI in patients with T2DM provide a greater net benefit.

Conclusions

The nomogram, composed of age, education, stroke, HbA1c level, Hcy level, and total CSVD burden score, had good predictive accuracy and may provide clinicians with a practical tool for predicting the risk of mild VCI in T2DM patients.

The Therapeutic Effect of Buyang Huanwu Decoction on Mild Cognitive Impairment (MCI) in Patients with Diabetes

OBJECTIVE

This study aims to comprehensively verify the efficacy of Buyang Huanwu Decoction in improving cognitive function in patients with diabetes.

METHODS

Patients clinically diagnosed with mild cognitive impairment (MCI) assigned to either the placebo group or the Buyang Huanwu Decoction group. After strict screening and exclusions, a total of 156 participants completed the clinical trial, with 76 in the placebo group and 80 in the Buyang Huanwu Decoction group.

RESULTS

After treatment, Buyang Huanwu Decoction group showed higher Mini-Mental State Examination and Montreal Cognitive Assessment scores compared to placebo (p < 0.05). Memory and Executive Screening, Boston Naming Test, and Animal Fluency Test scores were also higher in the treatment group (p < 0.05). No significant differences were found in DST and CDT scores (p > 0.05). Trail Making Test scores were lower in the treatment group (p < 0.05). No significant difference was observed between the two groups in terms of complications (p > 0.05).

CONCLUSION

Patients receiving Buyang Huanwu Decoction treatment demonstrated improvement in cognitive function, showing positive effects and providing preliminary evidence for the role of Buyang Huanwu Decoction in improving cognitive function in patients with diabetes. This suggests its potential for clinical application and further promotion.

Functional reorganization of memory processing in the hippocampus is associated with neuroprotector GLP-1 levels in type 2 diabetes

Type 2 diabetes (T2D) often impairs memory functions, suggesting specific vulnerability of the hippocampus. In vivo neuroimaging studies relating encoding and retrieval of memory information with endogenous neuroprotection are lacking. The neuroprotector glucagon-like peptide (GLP-1) has a high receptor density in anterior/ventral hippocampus, as shown by animal models. Using an innovative event-related fMRI design in 34 participants we investigated patterns of hippocampal activity in T2D (n = 17) without mild cognitive impairment (MCI) versus healthy controls (n = 17) during an episodic memory task. We directly measured neurovascular coupling by estimating the hemodynamic response function using event-related analysis related to encoding and retrieval of episodic information in the hippocampus. We applied a mixed-effects general linear model analysis and a two-factor ANOVA to test for group differences. Significant between-group differences were found for memory encoding, showing evidence for functional reorganization: T2D patients showed an augmented activation in the posterior hippocampus while anterior activation was reduced. The latter was negatively correlated with both GLP-1 pre- and post-breakfast levels, in the absence of grey matter changes. These results suggest that patients with T2D without MCI have pre-symptomatic functional reorganization in brain regions underlying episodic memory, as a function of the concentration of the neuroprotective neuropeptide GLP-1.

Prediction model for mild cognitive impairment in patients with type 2 diabetes using the autonomic function test

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is a risk factor for cognitive impairment, and reduced heart rate variability (HRV) has been correlated with cognitive impairment in elderly individuals. This study investigated risk factors and validated a predictive model for mild cognitive impairment (MCI) in patients with T2DM using an autonomic function test.

METHODS

Patients with T2DM, 50-85 years of age, who attended the diabetes clinic at Gyeongsang National University Hospital between March 2018 and December 2019, were included. A total of 201 patients had been screened; we enrolled 124 patients according to the inclusion and exclusion criteria in this study. Cognitive function was assessed using the Montreal Cognitive Assessment-Korean version (MOCA-K); MCI was defined as a total MOCA-K score ≤ 23. Risk factors for MCI in patients with T2DM, including demographic- and diabetes-related factors, and autonomic function test results, were analyzed. Based on multivariate logistic regression, a nomogram was developed as a prediction model for MCI.

RESULTS

Thirty-nine of 124 patients were diagnosed with MCI. Age, education, and decreased cardiovagal function were associated with a high risk for MCI, with cardiovagal function exerting the greatest influence. However, diabetes-related factors, such as glycemic control, duration of diabetes, or medications, were not associated with the risk for MCI. The nomogram demonstrated excellent discrimination (area under the curve, 0.832) and was well calibrated.

CONCLUSION

Approximately one-third of patients had MCI; as such, carefully evaluating cognitive function in elderly T2DM patients with reduced HRV is important to prevent progression to dementia.

Tangzhiqing decoction attenuates cognitive dysfunction of mice with type 2 diabetes by regulating AMPK/mTOR autophagy signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tangzhiqing decoction (TZQD) is an effective prescription developed by Jiangsu Province Hospital of Chinese Medicine for the treatment of diabetes mellitus (DM) and its complications, which has a clear cerebral protective effect on mice with diabetic cognitive dysfunction, but its specific mechanism has not been well elucidated.

AIMS OF THE STUDY

This study aims to verify the protection of TZQD on cognitive function in mice with type 2 diabetes mellitus (T2DM) and explore the possible underlying mechanisms.

MATERIALS AND METHODS

Six active ingredients in TZQD were detected using high-performance liquid chromatography analysis. In vivo experiments, the protection of TZQD on cognitive function and hippocampal neurons in type 2 diabetes mice was verified to obtain the optimal intervention dose of TZQD. TZQD and 3-methyladenine (3 MA) respectively or jointly intervened in mice with T2DM for 12 weeks, followed by detecting the cognitive difference, hippocampus cornu ammonis 1 (CA1) region injury, and hippocampal neuronal apoptosis in each group. Simultaneously, the investigation of autophagosome formation and organelle impairment in hippocampal neurons, along with the examination of AMPK/mTOR pathway proteins and autophagy-related proteins, was conducted to elucidate the potential mechanisms, through which TZQD modulates autophagy and enhances cognitive function. In vitro experiments, TZQD-containing serum and AMPK inhibitor Compound C (CC) were used to intervene in mouse hippocampal neuron HT22 cells under high glucose environment, further clarifying the regulatory role of TZQD on the AMPK/mTOR pathway and its impact on HT22 cell apoptosis and autophagy.

RESULTS

In vivo experiment results showed that TZQD had an obvious hypoglycemic effect. Different doses of TZQD could improve cognitive function and hippocampus damage in diabetes mice, with the middle dose of TZQD showing the best effect. TZQD increased the swimming speed of diabetes mice, improved their spatial recognition and memory ability, and reduced hippocampal neuronal apoptosis, Nissl body injury, and p-tau217 protein deposition. In addition, through transmission electron microscopy (TEM), immunofluorescence, and Western blot (WB) detection, TZQD significantly improved the organelle damage of hippocampal neurons in diabetes mice, promoted the formation of autophagy lysosomes, increased the expression of autophagy-related proteins like Beclin 1, LC3II/LC3I, LAMP1, and LAMP2, reduced the level of P62 and promoted autophagy flow, which, however, were all significantly weakened by 3 MA. Meanwhile, TZQD regulated the expressions of AMPK/mTOR pathway proteins. In vitro experimental study results showed that TZQD can regulate the expression ratio of p-AMPK/AMPK alpha 1 and p-mTOR/mTOR in HT22 cells under high glucose conditions and improved the morphology and vitality of HT22 cells. By employing techniques such as monodansylcadaverine (MDC) staining, Lysosomal red fluorescent probe staining, and Annexin V-FITC/PI double staining, the investigation revealed that TZQD administration resulted in enhanced autophagosome formation, preservation of a lysosomal acidic milieu, and consequent mitigation of HT22 cell apoptosis under high glucose conditions.

CONCLUSIONS

TZQD can regulate the AMPK/mTOR pathway to activate autophagy to attenuate hippocampal neuronal apoptosis, thereby protecting cognitive function in diabetic mice.

The prevalence of mild cognitive impairment and dementia among rural dwellers: A systematic review and meta-analysis

The mild cognitive impairment (MCI) and dementia in rural areas are increasingly attracting public attention. However, their prevalence is still unclear. This study aims to reveal the distribution of MCI and dementia in rural areas. We systematically searched PubMed, Web of Science, Embase, and PsycINFO up to June 2023 for cohort and cross-sectional studies. Meta-analysis was conducted using random-effects models to evaluate the prevalence of MCI and dementia. Thirty-five studies with 16,936 participants met the inclusion criteria. The pooled prevalence of MCI and dementia was 27 % (n = 12, 95 %CI = 0.21-0.32, I2 = 99.5 %, P < 0.001) and 7 % (n = 27, 95 %CI = 0.05-0.08, I2 = 99.30 %, P < 0.001), respectively. Subgroup analyses revealed that aged 60 years or older [(MCI: 29 %, 95 %CI = 0.20-0.38, I2 = 99.7 %, P < 0.001), (dementia: 9 % (95 %CI = 0.06-0.12, I2 = 99 %, P < 0.001)], female [(MCI: 29 %, 95 %CI = 0.19-0.40, I2 = 99.3 %, P < 0.001), (dementia: 7 %, 95 % CI = 0.04-0.12, I2 = 98.66 %, P < 0.001)], a-MCI (19 %, 95 %CI = 0.12-0.26, I2 = 97.62 %, P < 0.001) and AD (4 %, 95 %CI = 0.02-0.05, I2 = 98.60 %, P < 0.001) showed higher prevalence. The prevalence of MCI and dementia in rural China was 23 % (95 %CI = 0.18-0.29, I2 = 99.5 %, P < 0.001) and 6 % (95 %CI = 0.04-0.08, I2 = 99.6 %, P < 0.001), respectively. Implementing cognitive impairment screening and intervention measures is necessary to improve the cognitive function of the rural population.

Untargeted Metabolomic Profiling Reveals Differentially Expressed Serum Metabolites and Pathways in Type 2 Diabetes Patients with and without Cognitive Decline: A Cross-Sectional Study

Diabetes is recognized as a risk factor for cognitive decline, but the underlying mechanisms remain elusive. We aimed to identify the metabolic pathways altered in diabetes-associated cognitive decline (DACD) using untargeted metabolomics. We conducted liquid chromatography-mass spectrometry-based untargeted metabolomics to profile serum metabolite levels in 100 patients with type 2 diabetes (T2D) (54 without and 46 with DACD). Multivariate statistical tools were used to identify the differentially expressed metabolites (DEMs), and enrichment and pathways analyses were used to identify the signaling pathways associated with the DEMs. The receiver operating characteristic (ROC) analysis was employed to assess the diagnostic accuracy of a set of metabolites. We identified twenty DEMs, seven up- and thirteen downregulated in the DACD vs. DM group. Chemometric analysis revealed distinct clustering between the two groups. Metabolite set enrichment analysis found significant enrichment in various metabolite sets, including galactose metabolism, arginine and unsaturated fatty acid biosynthesis, citrate cycle, fructose and mannose, alanine, aspartate, and glutamate metabolism. Pathway analysis identified six significantly altered pathways, including arginine and unsaturated fatty acid biosynthesis, and the metabolism of the citrate cycle, alanine, aspartate, glutamate, a-linolenic acid, and glycerophospholipids. Classifier models with AUC-ROC > 90% were developed using individual metabolites or a combination of individual metabolites and metabolite ratios. Our study provides evidence of perturbations in multiple metabolic pathways in patients with DACD. The distinct DEMs identified in this study hold promise as diagnostic biomarkers for DACD patients.

Study protocol for a prediction model for mild cognitive impairment in older adults with diabetes mellitus and construction of a nurse-led screening system: a prospective observational study

INTRODUCTION

With an increasing number of older adults in China, the number of people with cognitive impairment is also increasing. To decrease the risk of dementia, it is necessary to timely detect mild cognitive impairment (MCI), which is the preliminary stage of dementia. The prevalence of MCI is relatively high among older adults with diabetes mellitus (DM); however, no effective screening strategy has been designed for this population. This study will construct a nurse-led screening system to detect MCI in community-dwelling older adults with DM in a timely manner.

METHODS AND ANALYSIS

A total of 642 participants with DM will be recruited (n=449 for development, n=193 for validation). The participants will be divided into MCI and none-MCI groups. The candidate predictors will include demographic variables, lifestyle factors, history of diseases, physical examinations, laboratory tests and neuropsychological tests. Univariate analysis, least absolute shrinkage and selection operator regression screening, and multivariate logistic regression analysis will be conducted to identify the outcome indicators. Based on the multivariate logistic regression equation, we will develop a traditional model as a comparison criterion for the machine learning models. The Hosmer-Lemeshow goodness-of-fit test and calibration curve will be used to evaluate the calibration. Sensitivity, specificity, area under the curves and clinical decision curve analysis will be performed for all models. We will report the sensitivity, specificity, area under the curve and decision curve analysis of the validation dataset. A prediction model with better performance will be adopted to form the nurse-led screening system.

ETHICS AND DISSEMINATION

This prospective study has received institutional approval of the Medical Ethics Committee of Qidong Hospital of TCM (QDSZYY-LL-20220621). Study results will be disseminated through conference presentations, Chinese Clinical Trial Registry and publication.

TRIAL REGISTRATION NUMBER

ChiCTR2200062855.

Association of hypoglycemic events with cognitive impairment in patients with type 2 diabetes mellitus: Protocol for a dose-response meta-analysis

INTRODUCTION

With an incidence rate as high as 46%-58%, hypoglycemia is a common complication of glycemic management among those suffering from type 2 diabetes mellitus(T2DM). According to preclinical research, hypoglycemia episodes may impair cognition by harming neurons. However, there is still controversy regarding the clinical evidence for the relationship between hypoglycemic events and the likelihood of cognitive impairment. Furthermore, little research has been done on the dose-response association between hypoglycemia incidents and the possibility of cognitive impairment. To address these knowledge gaps, the present research intends to update the comprehension of the association among hypoglycemic events and the risk of cognitive impairment and to clarify the correlation between dose and response by incorporating the most recent investigations.

METHOD AND ANALYSIS

This work has developed a protocol for a systematic review and meta-analysis that will examine, via a well-organized assessment of several databases, the relationship between the incidence of hypoglycemia and the probability of cognitive impairment. Observational studies investigating the connection between hypoglycemia episodes and cognitive impairment will be included. The databases that will be searched are PubMed, Web of Science, the Chinese Biomedical Literature Database (CBM), Cochrane Library, Embase, the China National Knowledge (CNKI), Wan Fang, the Chinese Science and Technology Periodical Database (VIP), and Du Xiu. Literature from the establishment of each database to December 2023 will be included in the search. Two researchers will independently screen the studies that satisfy the requirements for both inclusion and exclusion. A third researcher will be asked to mediate any disputes. The methodological caliber of the studies included will be assessed utilizing the Newcastle-Ottawa Scale (NOS) or the Joanna Briggs Institute (JBI) critical appraisal method. With regard to GRADE, which stands for Grading of Recommendations, Assessment, Development, and Evaluation, the quality of the evidence will be evaluated. ROBIS Tool will be used to evaluate the risk of bias in the development of the systematic review. If the data is accessible, meta-analysis and dose-response curve analysis will be employed by Stata software. However, if the data does not allow for such analysis, a descriptive review will be performed.

DISCUSSION AND CONCLUSION

Hypoglycemic episodes may raise the likelihood of cognitive impairment, according to earlier investigations. This study will update the relevant evidence and explore the dose-response connection between hypoglycemic episodes and cognitive impairment. The results of this review will have significant effects on decision-making by individuals with diabetes, healthcare providers, and government policy institutions.

TRIAL REGISTRATION

Prospero registration number: CRD42023432352.

Functional-structural decoupling in visual network is associated with cognitive decline in patients with type 2 diabetes mellitus: evidence from a multimodal MRI analysis

Type 2 diabetes mellitus (T2DM) and cognitive dysfunction are highly prevalent disorders worldwide. Although visual network (VN) alteration and functional-structural coupling are potential warning factors for mild cognitive impairment (MCI) in T2DM patients, the relationship between the three in T2DM without MCI is unclear. Thirty T2DM patients without MCI and twenty-nine healthy controls (HC) were prospectively enrolled. Visual components (VC) were estimated by independent component analysis (ICA). Degree centrality (DC), amplitude of low frequency fluctuation (ALFF) and fractional anisotropy (FA) were established to reflect functional and structural characteristics in these VCs respectively. Functional-structural coupling coefficients were further evaluated using combined FA and DC or ALFF. Partial correlations were performed among neuroimaging indicators and neuropsychological scores and clinical variables. Three VCs were selected using group ICA. Deteriorated DC, ALFF and DC-FA coefficients in the VC1 were observed in the T2DM group compared with the HC group, while FA and ALFF-FA coefficients in these three VCs showed no significant differences. In the T2DM group, DC in the VC1 positively correlated with 2 dimensions in the California Verbal Learning Test, including Trial 4 and Total trial 1-5. The impaired DC-FA coefficients in the VC1 markedly affected the Total perseverative responses % of the Wisconsin Card Sorting Test. These findings indicate that DC and DC-FA coefficients in VN may be potential imaging biomarkers revealing early cognitive deficits in T2DM.

Clinical characteristics and healthcare utilisation associated with undiagnosed cognitive impairment in elderly patients with diabetes in a primary care setting: a population-based cohort study

OBJECTIVES

The objective of this study is to report the prevalence, clinical characteristics and healthcare utilisation of patients with type 2 diabetes (T2DM) and previously undiagnosed cognitive impairment who were identified as having a low Montreal Cognitive Assessment (MoCA) score.

DESIGN

A population-based cohort study comparing clinical characteristics, medications, outpatient and inpatient care of patients with a MoCA score <19 to MoCA >26 using descriptive statistics, linear regression and multivariate logistic regression.

SETTING

Electronic medical records of a large health maintenance organisation in Israel.

PARTICIPANTS

350 patients, age >65 with T2DM who participated in a cognitive function screening initiative using MoCA, and had a follow-up visit during the 12 months after screening.

RESULTS

130 (37.1%) had a MoCA score >26 and 68 (19.4%) <19. Patients with MoCA<19 had more diabetes-related complications, poorer glycaemic and lipid control, fewer visits to their main primary care physician (PCP; 3.9±3.2 vs 7.3±4.2 visits/year p=0.008), shorter duration of PCP visits (8.3±4.5 vs 4.0±3.5 min, p=0.007), fewer nutritionist and endocrinologist visits, and lower participation in diabetes or smoking cessation workshops. They were less likely to be treated with glucagon-like peptide-1 (GLP-1) agonists, dipeptidyl peptidase-4 inhibitor (DPP-4), or sodium-glucose transport protein 2 (SGLT-2) inhibitors and more likely to receive insulin or sulfonylurea. Moreover, they had more emergency room visits (ER; 15 (11.5%) vs 16 (23.5%), p=0.019), hospitalisations (8 (6.2%) vs 22 (32.4%), p=0.001), and longer hospital stays (4.3±3.2 vs 14.5±9.8, p=0.001). Using statistical models, MoCA<19 was identified as a risk factor for fewer and shorter PCP visits and more ER visits and hospitalisations.

CONCLUSIONS

This study highlights the high prevalence of undiagnosed severe cognitive impairment in elderly patients with T2DM and its association with poor outpatient care. Appropriate interventions are needed to improve outcomes and prevent hospitalisation in this high-risk population.

Inconsistencies in self-reported diabetes in a large panel study: the Survey of Health, Ageing and Retirement in Europe (SHARE)

BACKGROUND

The validity of self-reported chronic conditions has been assessed by comparing them with medical records or register data in several studies. However, the reliability of self-reports of chronic diseases has less often been examined. Our aim was to assess the proportion and determinants of inconsistent self-reports of diabetes in a long panel study.

METHODS

SHARE (Survey of Health, Ageing and Retirement in Europe) includes 140,000 persons aged ≥ 50 years from 28 European countries and Israel. We used data from waves 1 to 7 (except wave 3) collected between 2004 and 2017. Diabetes was assessed by self-report. An inconsistent report for diabetes was defined as reporting the condition in one wave, but denying it in at least one later wave. The analysis data set included 13,179 persons who reported diabetes, and answered the question about diabetes in at least one later wave. Log-binomial regression models were fitted to estimate crude and adjusted relative risks (RR) with 95% confidence intervals (CI) for the associations between various exposure variables and inconsistent report of diabetes.

RESULTS

The proportion of persons with inconsistent self-reports of diabetes was 33.0% (95% CI: 32.2%-33.8%). Inconsistencies occurred less often in persons taking antidiabetic drugs (RR = 0.53 (0.53-0.56)), persons with BMI ≥ 35 kg/m2 versus BMI < 25 kg/m2 (RR = 0.70, (0.64-0.77)), and poor versus excellent subjective health (RR = 0.87 (0.75-1.01)). Inconsistencies occurred more often in older persons (RR = 1.15 (1.12-1.18) per 10 years increase of age), and persons not reporting their age at diabetes onset (RR = 1.38 (1.31-1.45)).

CONCLUSION

In SHARE, inconsistent self-report of diabetes is frequent. Consistent reports are more likely for persons whose characteristics make diabetes more salient, like intake of antidiabetic medication, obesity, and poor subjective health. However, lack of attention in answering the questions, and poor wording of the items may also play a role.

An extract of Hibiscus sabdariffa improves short-term memory in rats with experimental diabetic hyperglycemia

BACKGROUND

Calyxes of Hibiscus sabdariffa (Hs) contain anthocyanins, that normalize blood glucose levels (BGL) in diabetic patients. Diabetes also causes memory alterations, which could hypothetically decrease with the consumption of Hs.

OBJECTIVES

To investigate the effect of dietary supplementation with a Hs extract on working memory and BGL in rats.

METHODS

Diabetic hyperglycemia (DHG) was induced with streptozotocin (STZ, 55 mg/kg i.p.) in Wistar rats. After 72 h DHG was confirmed, and the consumption of Hs extract began (50 mg/Kg/day). BGL and body weight (BW) were measured at 10, 20 and 30 days after DHG induction in controls and treated animals. Learning and short-term memory were evaluated after 30 days with Novel Object Recognition Test (NOR) and Barnes Maze (BM). The gross hippocampal structure was histologically analyzed.

RESULTS

STZ-treated animals presented low BW and persistent DHG (BGL <300 mg/dL). Diabetic animals consuming the Hs extract had a dual response: some showed BGL comparable to controls, while others had levels comparable to diabetic animals not consuming extract. Diabetic animals that consumed the Hs extract had a better performance in NOR and BM than the diabetic animals not consuming the extract. At the histological level, hippocampal morphological differences were observed between diabetic animals that consumed the extract and those that did not.

DISCUSSION

The Hs extract used here could be a good co-adjuvant in the treatment of DHG, aimed at mitigating memory deficits and high BGL. These beneficial effects could be attributed to the anthocyanin content in the extract.

Cognitive deficits among people with schizophrenia and prediabetes or diabetes

INTRODUCTION

Both type 2 diabetes mellitus (T2DM) and schizophrenia are known to be associated with cognitive deficits. The impact of the comorbidities of T2DM or prediabetes (PD) on cognition among people with schizophrenia has been poorly researched. We evaluated the cognitive functioning of patients with schizophrenia and PD or T2DM and compared them to patients with schizophrenia with normal blood sugar.

METHODS

We retrospectively collated data on cognition, fasting blood glucose (FBG), lipids and other selected demographic and clinical variables of 171 patients with schizophrenia and 16 patients with schizoaffective disorder who were admitted to an inpatient rehabilitation facility in Western Australia from 2011 to 2018. The Brief Assessment of Cognition in Schizophrenia (BACS) was used to evaluate cognitive functioning. Parametric and non-parametric analyses were used to examine the study's aims.

RESULTS

Sixty-six percent of the patients had normal blood sugar, 25% had PD and 9% had T2DM. The BACS composite score revealed an increasing gradient of cognitive deficits, ranging from mild to severe, between the normal, PD and T2DM groups, respectively. The T2DM group had a significantly lower composite score compared with the PD (p = 0.026) and normal groups (p < 0.001). On the BACS subtests, the scores of T2DM and PD patients were similar except for the token motor task, in which the T2DM group had significantly lower scores (p < 0.001). The T2DM group also had lower scores on the subtests of BACS, except memory tests, compared with those with normal blood sugar. There was no significant difference in the composite and subtest cognitive scores between the PD and normal groups.

CONCLUSIONS

Our study revealed more pronounced cognitive deficits among patients with schizophrenia and dysglycaemia, particularly those with T2DM, compared with those with schizophrenia with normal blood sugar.

Intermittent fasting and Alzheimer's disease-Targeting ketone bodies as a potential strategy for brain energy rescue

Alzheimer's disease (AD) lacks effective clinical treatments. As the disease progresses, the cerebral glucose hypometabolism that appears in the preclinical phase of AD gradually worsens, leading to increasingly severe brain energy disorders. This review analyzes the brain energy deficit in AD and its etiology, brain energy rescue strategies based on ketone intervention, the effects and mechanisms of IF, the differences in efficacy between IF and ketogenic diet and the duality of IF. The evidence suggests that brain energy deficits lead to the development and progression of AD pathology. IF, which improves brain energy impairments by promoting ketone metabolism, thus has good therapeutic potential for AD.

Effects of Type 2 Diabetes on the Neuropsychological Profile in Mild Cognitive Impairment

Background

Diabetes is one of the main risk factors for developing mild cognitive impairment (MCI) and Alzheimer's disease. Most studies have demonstrated a worse performance in executive function, verbal fluency, and information processing speed in patients with diabetes.

Objective

To assess the cognitive functioning of persons with type 2 diabetes and amnesic mild cognitive impairment (aMCI-T2DM) compared to persons with aMCI without diabetes and persons without diabetes or aMCI as controls, to understand the role of diabetes in the neuropsychological profile.

Methods

Cross-sectional study involving a sample of 83 patients, ranging in age from 61 to 85 years and divided into three groups: aMCI-T2DM (27 patients), aMCI (29 patients), Controls (27 individuals). All the participants undertook an exhaustive neuropsychological assessment (auditory-verbal and visual memory, attention, information processing speed, language, executive function, and depression).

Results

Both groups of aMCI patients performed significantly worse than the controls in all the neuropsychological tests. A significant linear tendency (p trend < 0.05) was found between groups, with the aMCI-T2DM group presenting worse results in global cognition assessed by the Mini-Mental State Examination and Montreal Cognitive Assessment; Rey-Osterrieth Complex Figure Test; Auditory Verbal Learning Test; Trail Making Test A and B, Verbal Fluency Test, and Hamilton Depression Rating Scale.

Conclusions

aMCI patients with or without diabetes showed worse cognitive function compared to persons without diabetes or aMCI. Additionally, aMCI patients without T2DM presented a different cognitive profile than aMCI patients with T2DM, which tended towards presenting worse cognitive functions such as global cognition, memory, attention, executive function, and language.

Structural and Metabolic Retinal Changes Associated With Mild Cognitive Impairment in Type 2 Diabetes

Type 2 diabetes is associated with cognitive impairment and a twofold increased risk of dementia compared with age-matched individuals without diabetes. Given that the eye and the brain share similar embryologic origin and anatomical features, the retina offers a unique window to the brain. In this study, we wanted to determine whether there was a difference in retinal imaging-based neuronal and vascular markers in individuals with type 2 diabetes with or without mild cognitive impairment (MCI). We included 134 persons with type 2 diabetes. Based on neuropsychological tests, the prevalence of MCI was 28%. We performed seven-field color fundus photos, optical coherence tomography (OCT), OCT-angiography (OCT-A), and retinal oximetry to analyze retinal markers. In a multivariable cluster analysis, persons with MCI had a significantly thinner macular retinal nerve fiber layer and macular ganglion cell layer, and less venular oxygen saturation in the nasal quadrant compared with those without MCI. There were no differences in retinal vessel density, fractal dimension, width, tortuosity, or OCT-A markers. People with type 2 diabetes and MCI demonstrate alterations in retinal structure and metabolism, suggesting noninvasive retinal markers may be useful to detect people with type 2 diabetes at risk for cognitive dysfunction.

ARTICLE HIGHLIGHTS

Type 2 diabetes is associated with mild cognitive impairment (MCI). Therefore, retinal and cerebral neurodegeneration may run in parallel. To assess whether there was a difference in retinal structure, vessel, and metabolic parameters in individuals with MCI. We found those with MCI had a thinner macular retinal nerve fiber layer, macular ganglion cell layer, and less venular oxygen saturation. We suggest noninvasive retinal markers may be useful to detect those at risk of cognitive dysfunction.

Gut microbiota regulation of inflammatory cytokines and microRNAs in diabetes-associated cognitive dysfunction

Type 2 diabetes mellitus (T2DM) has a major comorbidity known as diabetes-associated cognitive dysfunction (DACD). Studies have demonstrated that the gut microbiota is crucial in mediating the cognitive abnormalities that occur in diabetic individuals. Additionally, changes in dietary fatty acid intake levels, inflammatory cytokines, and microRNAs (miRs) have an effect on cognitive performance. However, further studies are needed to identify the link between gut microbiota and cognition in T2DM patients and the role that the above indicators play in this process. In order to provide a new rationale for the treatment of cognitive dysfunction in diabetes, this study was conducted in the middle-aged and elderly Beijing population to examine the differences in gut microbiota between DACD and T2DM patients as well as to further explore the role of erythrocyte membrane fatty acids, inflammatory cytokines, and miRs in gut microbiota-mediated cognitive impairment. According to the results, the abundance of norank_f_Eubacterium_coprostanoligenes_group, Acidaminococcus, Enterorhabdus, and norank_f_Clostridium_methylpentosum_group was higher in DACD patients compared to T2DM patients at the genus level. Compared with T2DM patients, plasma interleukin-12 (IL-12) concentrations were significantly higher in DACD patients than in T2DM patients, and IL-12 was significantly positively correlated with norank_f_Eubacterium_coprostanoligenes_group. In addition, plasma miR-142-5p was significantly positively correlated with Enterorhabdus and norank_f_Eubacterium_coprostanoligenes_group. We therefore hypothesize that cognitive impairment in T2DM patients is associated with altered gut microbial composition and that the effect of microbiota on cognition may be mediated through IL-12 and miR-142-5p. KEY POINTS: • Type 2 diabetes with or without cognitive impairment differs in gut microbiota. • Differential genera of gut microbiota were associated with inflammatory cytokines. • Differential genera of gut microbiota were associated with plasma microRNAs.

A longitudinal study of polygenic score and cognitive function decline considering baseline cognitive function, lifestyle behaviors, and diabetes among middle-aged and older US adults

BACKGROUND

Genomic study of cognition decline while considering baseline cognition and lifestyle behaviors is scarce. We aimed to evaluate the impact of a polygenic score for general cognition on cognition decline rate, while considering baseline cognition and lifestyle behaviors, among the general population and people with diabetes, a patient group commonly affected by cognition impairment.

METHODS

We tested associations of the polygenic score for general cognition with annual changing rates of cognition measures in 8 years of follow-up among 12,090 White and 3100 Black participants of the Health and Retirement Study (HRS), a nationally representative sample of adults aged 50 years and older in the USA. Cognition measures including word recall, mental status, and total cognitive score were measured biannually. To maximize sample size and length of follow-up, we treated the 2010 wave of survey as baseline, and follow-up data until 2018 were analyzed. Baseline lifestyle behaviors, APOE status, and measured cognition were sequentially adjusted. Given racial differences in polygenic score, all analyses were conducted by race.

RESULTS

The polygenic score was significantly associated with annual changing rates of all cognition measures independent of lifestyle behaviors and APOE status. Together with age and sex, the polygenic score explained 29.9%, 15.9%, and 26.5% variances of annual changing rates of word recall, mental status, and total cognitive scores among Whites and explained 17.2%, 13.9%, and 18.7% variance of the three traits among Blacks. Among both White and Black participants, those in the top quartile of polygenic score had the three cognition measures increased annually, while those in the bottom quartile had the three cognition measures decreased annually. After further adjusting for the average cognition assessed in 3 visits around baseline, the polygenic score was still positively associated with annual changing rates of all cognition measures for White (P ≤ 2.89E - 19) but not for Black (P ≥ 0.07) participants. In addition, among participants with diabetes, physical activity offset the genetic susceptibility to decline of mental status (interaction P ≤ 0.01) and total cognitive scores (interaction P = 0.03).

CONCLUSIONS

Polygenic score predicted cognition changes in addition to measured cognition. Physical activity offset genetic risk for cognition decline among diabetes patients.

Stratified support pattern-based internet-assisted self-management therapy for diabetes mellitus -mild cognitive impairment: a randomized controlled trial protocol

BACKGROUND

Mild cognitive impairment (MCI) associated with diabetes mellitus (DM) is common among older adults, and self-management is critical to controlling disease progression. However, both MCI and DM are heterogeneous diseases, and existing integrated self-management interventions do not consider patient differences. Grouping patients by disease characteristics could help to individualize disease management and improve the use of available resources. The current study sought to explore the feasibility and effectiveness of a stratified support model for DM-MCI patients.

METHODS

Eighty-four DM-MCI patients will be randomly divided into an intervention group and a control group in a 1:1 ratio. The intervention group will receive a self-management intervention using the stratified support pattern-based internet-assisted therapy (SISMT), while the control group will receive the health manual intervention (HMI). The study recruiter will be blinded to the group allocation and unable to foresee which group the next participant will be assigned to. At the same time, the allocation will be also hidden from the research evaluators and participants. After 12 weeks and 24 weeks, cognitive function, blood glucose, self-management ability, psychological status, health literacy, and self-management behavior of patients in both groups will be measured and compared.

DISCUSSION

This study developed a stratified support pattern-based internet-assisted to provide self-management intervention for patients with DM-MCI. The impact of different models and forms of self-management intervention on cognitive function, blood glucose management, and psychological status health literacy and self-management behavior of patients will be assessed. The results of this study will inform related intervention research on the stratified support pattern-based internet-assisted self-management therapy, and help to slow the decline of cognitive function in patients with DM-MCI.

TRIAL REGISTRATION

ChiCTR2200061991. Registered 16 July 2022.

Impact of Cardiac Autonomic Dysfunction on Cognitive Event-Related Potential in Type 2 Diabetes Mellitus Patients: A Cross-Sectional Study

Introduction

Type 2 diabetes mellitus (T2DM) is a chronic metabolic condition that is responsible for various long-term complications. Cognitive impairment is one of the most common complications, but the underlying mechanisms are still undetermined. The autonomic imbalance is a major cause for CVS morbidity in T2DM which could also potentially affect cognition. But there is sparse data available in the literature to prove the association between autonomic dysfunction and cognitive impairment.

Methodology

We recruited 40 T2DM patients and 40 healthy controls. The assessment of cognitive functions was done by cognitive P300 event-related potential (ERP) and MoCA. Heart rate variability (HRV) was done to assess autonomic function.

Results

The P300 ERP latency in Fz, Cz and Pz sites was significantly prolonged in T2DM patients (P < 0.001). We found moderate correlation is present between P300 latency and total power (r = -0.466, P < 0.01) and LFnu (r = -0.423, P < 0.01) in T2DM patients. The total power and HbA1C show independent association with P300 latency after adjustment for confounding factors like age and duration of diabetes (P < 0.05).

Conclusion

As the incidence of Alzheimer's disease is rising among T2DM patients increasing their dependency, making necessary lifestyle measures at earliest to improve autonomic balance may prevent or delay the onset of cognitive decline and alleviate its consequences and improve the quality of life in T2DM patients.

Correlation between inflammatory biomarkers, cognitive function and glycemic and lipid profiles in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

This study aimed to quantitatively estimate the correlation between systemic inflammation with cognitive function, as well as glycemic and lipid profiles in patients with type 2 diabetes mellitus (T2DM). The PubMed, Web of Science, EMBASE, SCOPUS, CNKI, Wanfang, VIP, and CBM databases were searched from its inception until June 2023 (PROSPERO registration: CRD42022356889). We analyzed data extracted from observational studies to quantify the correlations (r) as the pooled effect size and further performed subgroup analyses and sensitivity analyses. A total of 32 studies involving 7,483 patients with T2DM were included. The findings revealed a significant moderate negative correlation between interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) levels with Montreal Cognitive Assessment scores. TNF-α levels also had moderate negative correlation with Mini-Mental State Examination scores. For glycemic and lipid profiles, there was a significant moderate positive correlation between CRP and TNF-α levels and glycated hemoglobin (HbA1c), and TNF-α levels were also found to be lowly positively correlated with fasting blood glucose (FBG). CRP levels were found to have a low positive correlation with total cholesterol (TC), and IL-6 levels were found to be lowly positively correlated with triglycerides. The results indicate that elevated levels of IL-6, CRP, and TNF-α are significantly associated with cognitive impairment in patients with T2DM and may serve as inflammatory markers for T2DM with mild cognitive impairment. The CRP and TNF-α levels were more strongly correlated with HbA1c than with FBG and TC. Further research is needed to determine the clinical value of these inflammatory biomarkers and to investigate potential causal mechanisms underlying this association.

Prevalence and incidence of mild cognitive impairment in adults with diabetes in the United States

BACKGROUND

Limited evidence exists about the prevalence and incidence of mild cognitive impairment (MCI) in individuals with diabetes in the U.S. We aimed to address such knowledge gaps using a nationally representative study dataset.

METHOD

We conducted a secondary analysis from the Health and Retirement Study (HRS) (1996-2018). The sample for examining the prevalence of MCI was14,988, with 4192 (28.0%) having diabetes, while the sample for the incidence was 21,824, with 1534 (28.0%) having diabetes.

RESULTS

Participants with diabetes had a higher prevalence of MCI than those without diabetes (19.9 % vs. 14.8 %; odds ratio [95 % confidence interval] (OR[95 %CI]): 1.468 [1.337, 1.611], p <.001). The incidence of MCI in participants with/without newly diagnosed diabetes was 42.9 % vs. 31.6 % after a mean 10-year follow-up, with the incidence rate ratio (IRR) [95 %CI] (1.314 [1.213, 1.424], p <.001). Newly diagnosed diabetes was associated with elevated risks of MCI compared with non-diabetes, with the uncontrolled hazard ratio (HR) [95 %CI] (1.498 [1.405, 1.597], p <.001).

CONCLUSIONS

Using a nationally representative study data in the U.S., participants with diabetes had a higher prevalence and incidence of MCI than those without diabetes. Findings show the importance of developing interventions tailored to the needs of individuals with diabetes and cognitive impairment.

Effectiveness of Combined Aerobic and Resistance Exercise on Cognition, Metabolic Health, Physical Function, and Health-related Quality of Life in Middle-aged and Older Adults With Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the effectiveness of combined aerobic and resistance exercise on cognition, metabolic health, physical function, and health-related quality of life (HRQoL) in middle-aged and older adults with type 2 diabetes mellitus (T2DM).

DATA SOURCE AND STUDY SELECTION

Systematic search of CINAHL, Cochrane, EMBASE, Scopus, PubMed, ProQuest Dissertation and Thesis, PsycINFO, Web of Science databases, and gray literature from Google Scholar. Pertinent randomized controlled trials (RCTs) were selected. The Protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42023387336).

DATA EXTRACTION

The risk of bias was evaluated using the Cochrane Risk of Bias tool by 2 reviewers independently. Outcome data were extracted in a fixed-effect model if heterogeneity test were not significant and I2≤50%; otherwise, the random-effects model was used.

DATA SYNTHESIS

Sixteen studies with 2426 participants were included in this review. Combined aerobic and resistance exercise had significant positive effects on cognition (SMD=0.34, 95% CI: 0.13 to 0.55), metabolic health on HbA1c (SMD=-0.35, 95% CI: -0.48 to -0.22) and lipid profile (total cholesterol SMD=-0.20, 95% CI: -0.34 to -0.07; low-density lipoprotein SMD=-0.19, 95% CI: -0.33 to -0.05; high-density lipoprotein SMD=0.25, 95% CI: 0.12 to 0.39; and triglycerides SMD=-0.18, 95% CI: -0.31 to -0.04), physical function on aerobic oxygen uptake (SMD=0.58, 95% CI: 0.21 to 0.95) and body mass index (MD=-1.33, 95% CI: -1.84 to -0.82), and physical HRQoL (MD=4.17, 95% CI: 0.86 to 7.48). Our results showed that clinically important effects on cognition may occur in combining the low-moderate intensity of aerobic exercise and progressive intensity of resistance training, the total duration of the exercise needs to be at least 135 minutes per week, among which, resistance training should be at least 60 minutes.

CONCLUSION

Combined aerobic and resistance exercise effectively improves cognition, ameliorates metabolic health, enhances physical function, and increases physical HRQoL in middle-aged and older adults with T2DM. More RCTs and longitudinal follow-ups are required to provide future evidence of structured combined aerobic and resistance exercise on other domains of cognition.

Physiological Mechanisms Inherent to Diabetes Involved in the Development of Dementia: Alzheimer's Disease

Type 2 diabetes mellitus (T2D) is a metabolic disease reaching pandemic levels worldwide. In parallel, Alzheimer's disease (AD) and vascular dementia (VaD) are the two leading causes of dementia in an increasingly long-living Western society. Numerous epidemiological studies support the role of T2D as a risk factor for the development of dementia. However, few basic science studies have focused on the possible mechanisms involved in this relationship. On the other hand, this review of the literature also aims to explore the relationship between T2D, AD and VaD. The data found show that there are several alterations in the central nervous system that may be promoting the development of T2D. In addition, there are some mechanisms by which T2D may contribute to the development of neurodegenerative diseases such as AD or VaD.

Prevalence of impaired awareness of hypoglycaemia in people with diabetes mellitus: A systematic review and meta-analysis from 21 countries and regions

AIMS

Impaired awareness of hypoglycaemia (IAH) is a complication of glucose-lowering therapies for diabetes. The purpose of this review was to estimate the pooled prevalence of IAH and unawareness of hypoglycaemia (UAH).

METHODS

We searched the major databases from inception to 8 August 2022 and included all cross-sectional and cohort studies reporting IAH prevalence in people with diabetes. A random-effects model was used to pool effect values. Subgroup analysis and meta-regression were used to identify study-level characteristics affecting prevalence.

RESULTS

Sixty-two studies from 21 countries published between 2000 and 2022 were included, with 39,180 participants (type 1 diabetes: 19,304 vs. Type 2 diabetes: 14,650). The pooled prevalence was 23.2% (95% CI: 18.4%-29.3%) via the Clarke questionnaire, 26.2% (95% CI: 22.9%-29.9%) via the Gold score, and 58.5% (95% CI: 53.0%-64.6%) via the Pedersen-Bjergaard method, all from studies classified as presenting a moderate and low risk of bias. The prevalence of IAH was generally higher in people with type 1 diabetes than in those with type 2 diabetes and lowest in Europe. Meta-regression results show that the duration of diabetes was a factor influencing the prevalence of IAH. The prevalence of UAH by the Pedersen-Bjergaard method was 17.6 (95% CI: 14.9%-20.3%).

CONCLUSIONS

IAH is a prevalent risk event among people with type 1 and type 2 diabetes, showing clinical heterogeneity and regional variability. UAH, an adverse progression of IAH, is also a serious burden. More primary research on the prevalence of IAH is needed in areas with a high diabetes burden.

Dexmedetomidine Regulates Autophagy via the AMPK/mTOR Pathway to Improve SH-SY5Y-APP Cell Damage Induced by High Glucose

Neurodegenerative diseases and postoperative cognitive dysfunction involve the accumulation of β-amyloid peptide (Aβ). High glucose can inhibit autophagy, which facilitates intracellular Aβ clearance. The α2-adrenoreceptor agonist dexmedetomidine (DEX) can provide neuroprotection against several neurological diseases; however, the mechanism remains unclear. This study investigated whether DEX regulated autophagy via the AMPK/mTOR pathway to improve high glucose-induced neurotoxicity in SH-SY5Y/APP695 cells. SH-SY5Y/APP695 cells were cultured with high glucose with/without DEX. To examine the role of autophagy, the autophagy activator rapamycin (RAPA) and autophagy inhibitor 3-methyladenine (3-MA) were used. The selective AMPK inhibitor compound C was used to investigate the involvement of the AMPK pathway. Cell viability and apoptosis were examined by CCK-8 and annexin V-FITC/PI flow cytometric assays, respectively. Autophagy was analyzed by monodansylcadaverine staining of autophagic vacuoles. Autophagy- and apoptosis-related protein expression and the phosphorylation levels of AMPK/mTOR pathway molecules were quantified by western blotting. DEX pretreatment significantly suppressed high glucose-induced neurotoxicity in SH-SY5Y/APP695 cells, as evidenced by the enhanced viability, restoration of cellular morphology, and reduction in apoptotic cells. Furthermore, RAPA had a protective effect similar to that of DEX, but 3-MA eliminated the protective effect of DEX by promoting mTOR activation. Moreover, the AMPK/mTOR pathway was involved in DEX-mediated autophagy. Compound C significantly suppressed autophagy and reversed the protective effect of DEX against high glucose in SH-SY5Y/APP695 cells. Our findings demonstrated that DEX protected SH-SY5Y/APP695 cells against high glucose-induced neurotoxicity by upregulating autophagy through the AMPK/mTOR pathway, suggesting a role of DEX in treating POCD in diabetic patients.

The Relationship between Trait Impulsivity and Everyday Executive Functions among Patients with Type 2 Diabetes Mellitus: The Mediating Effect of Negative Emotions

Background

In recent years, the incidence of type 2 diabetes mellitus (T2DM) has dramatically increased, imposing a heavy financial burden on society and individuals. The most cost-effective way to control diabetes is diabetes self-management, which depends on patients' executive functions (EFs). However, the level of EFs among patients with T2DM varies greatly. In addition to diabetes-related factors contributing to a decline in EFs, trait impulsivity as a relatively stable personality trait may explicate individual differences in EFs. The objective of this study was to verify the mediating effect of negative emotions on the relationship between trait impulsivity and EFs among patients with T2DM in China.

Methods

A total of 305 patients with T2DM were enrolled consecutively from the endocrinology departments of three tertiary hospitals in China using convenience sampling. The participants completed the Sociodemographic Questionnaire, Mini-Mental State Examination (MMSE), Barratt Impulsiveness Scale-Brief (BIS-Brief), Depression Anxiety and Stress Scales with 21 items (DASS-21), and Behavior Rating Inventory of Executive Function-Adult (BRIEF-A) version. A structural equation modeling was used to verify the mediating effect of negative emotions on the relationship between trait impulsivity and EFs.

Results

A total of 32.46% of the participants experienced at least one aspect of daily EF decline. The mediating effect of trait impulsivity on the Behavioral Regulation Index (BRI) of EFs through negative emotions was significant, accounting for 29.57% of the total effect. The mediating effect of trait impulsivity on the Metacognitive Index (MI) of EFs through negative emotions was significant, accounting for 31.67% of the total effect.

Conclusions

Trait impulsivity can positively predict EF decline, which can be alleviated by improving the negative emotions of patients with T2DM. Future research exploring interventions to improve the EFs of patients with T2DM should therefore consider their trait impulsivity and negative emotions.

Relationships Between Body Composition and Cognitive Impairment in Hospitalised Middle-Aged Type 2 Diabetic Patients

Objective

The aim of this study was to elucidate the relationship between specific body composition and the risk of Cognitive Impairment (CI) in middle-aged Type 2 Diabetes Mellitus (T2DM) patients.

Methods

This cross-sectional study included 504 hospitalized patients with T2DM from the Department of Endocrinology and Metabolism of the Tianjin Union Medical Center. Subjects were grouped by sex, and cognitive status was assessed using the Montreal Cognitive Assessment (MoCA). The relationship between body composition and cognitive ability was investigated with the use of linear regression analysis. The association between body composition and CI risk was determined by logistic regression analysis.

Results

The prevalence of CI was 39.3% in middle-aged T2DM patients. After adjusting for age, education, marriage status, carotid atherosclerosis, cerebrovascular disease and hemoglobin, multiple linear regression analysis showed that lean mass index (LMI), body mass index (BMI) and appendicular skeletal muscle index (SMI) were significant predictors for the MoCA scores in men (p < 0.05). In addition, BMI (OR 0.913, 95% CI 0.840-0.992) and LMI (OR 0.820, 95% CI 0.682-0.916) were independent protective factors for CI in males. After adjusted for age, education, marriage status, dietary control of diabetes and cerebrovascular disease, visceral obesity (VO, OR 1.950, 95% CI 1.033-3.684) and abdominal obesity (AO, OR 2.537, 95% CI 1.191-5.403) were risk factors for CI in female patients.

Conclusion

The results suggest that there may be different mechanisms underlying the relationship of body compositions and cognitive performance between middle-aged male and female patients with T2DM. In addition, our finding of potential determinants of cognitive impairment may facilitate the development of intervention programs for middle-aged type 2 diabetic patients. Nevertheless, more large prospective studies looking at cognition and changes in body composition over time are needed in the future to further support their association.

Comparison of the relationship between cognitive function and future falls in Chinese community-dwelling older adults with and without diabetes mellitus

OBJECTIVE

The aim of this study was to determine whether cognitive function is associated with future falls in older patients with diabetes mellitus (DM) compared with those without DM. Cognitive function was divided into several domains to further analyze.

METHODS

A total of 678 individuals met the inclusion criteria and comprised the final study population. The mean age was 74.35 ± 5.35 years, and 58.9% of the participants were female (n = 400). At the baseline, cognitive function was measured by the Mini Mental State Examination (MMSE), and DM diagnoses were determined by medical records. The self-reported any falls data were obtained via face-to-face questioning at the 1-year follow-up.

RESULTS

At baseline, 15.6% of participants (n = 106) were diagnosed with DM. According to whether they had any falls during 1-year follow-up, there was a significant difference between the two group in fasting plasma glucose (p = 0.012) and DM (p = 0.036) at baseline. Among the older adults with DM, those who had experienced any falls had poorer cognitive function (p = 0.014). After adjusting for various covariates, we found that MMSE (95% CI 0.790-0.991, p = 0.034), orientation to place (95% CI 0.307-0.911, p = 0.022) and registration (95% CI 0.162-0.768, p = 0.009) were significantly associated with falls in the follow-up.

CONCLUSION

Our study found that in patients with DM, cognitive function is related to future falls. Not only overall cognitive function, but also orientation to place and registration were all associated with future falls in older adults with DM. When completing the fall risk assessment of elderly patients with DM, clinicians should give more attention to the testing of cognitive function.

Rosa canina L. improves learning and memory-associated cognitive impairment by regulating glucose levels and reducing hippocampal insulin resistance in high-fat diet/streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Recent studies claim that Type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) overlap in several common pathological pathways which from neuronal damage to impaired memory performance. It is known that the use of Rosa canina L. (R. canina) as medicine in folk medicine dates back to ancient times and is used in the treatment of nervous diseases in Persian medicine. However, the effect of R. canina on diabetes-related cognitive decline and memory impairment has not yet been studied.

AIM OF THE STUDY

We evaluated the impact of T2DM on AD-like alterations and examined the molecular mechanism of a possible effect of R. canina on cognitive alterations in diabetic rats.

MATERIALS&METHODS

R. canina ethanol extract was obtained by maceration method. This study was performed with male Spraque-Dawley rats fed with a high-fat diet (HFD) for 8 weeks, low-dose streptozotocin (STZ; 35 mg/kg IP) injection for 4 weeks, and R. canina (250 mg/kg; per oral) and metformin (400 mg/kg; per oral) administration for 4 weeks. The weight and blood glucose of rats were measured weekly. To evaluate glucose tolerance area under the curve (AUC) was calculated by performing an oral glucose tolerance test. Then the rats were subjected to behavioural tests, and their hippocampus and cortex tissues were obtained for biochemical and morphological analyses.

RESULTS

R. canina could manage glucose responsiveness by reducing post-prandial blood glucose levels, preventing weight loss, and raising serum insulin levels in T2DM-induced rats. Behavioural tests showed that R. canina significantly improves diabetes-related cognitive decline in recall and long-term memory. Treatment with R. canina significantly reversed HFD/STZ-induced increases in insulin, amyloid-β, amyloid precursor protein levels, and acetylcholinesterase activity in the prefrontal cortex and hippocampus. Furthermore, histological analyzes revealed the protection of R. canina against neuronal disruption in the cortical and hippocampal CA3 region caused by chronic hyperglycemia.

CONCLUSION

Analyzed collectively, these results suggest that R. canina can correct T2DM-related cognitive decline may be attributed to insulin pathway modulation, prevention of amyloid deposition, and increased cholinergic transmission.

The Role of a Ketogenic Diet in the Treatment of Dementia in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) shares a common molecular mechanism and underlying pathology with dementia, and studies indicate that dementia is widespread in people with T2DM. Currently, T2DM-induced cognitive impairment is characterized by altered insulin and cerebral glucose metabolism, leading to a shorter life span. Increasing evidence indicates that nutritional and metabolic treatments can possibly alleviate these issues, as there is a lack of efficient preventative and treatment methods. The ketogenic diet (KD) is a very high-fat, low-carbohydrate diet that induces ketosis in the body by producing a fasting-like effect, and neurons in the aged brain are protected from damage by ketone bodies. Moreover, the creation of ketone bodies may improve brain neuronal function, decrease inflammatory expression and reactive oxygen species (ROS) production, and restore neuronal metabolism. As a result, the KD has drawn attention as a potential treatment for neurological diseases, such as T2DM-induced dementia. This review aims to examine the role of the KD in the prevention of dementia risk in T2DM patients and to outline specific aspects of the neuroprotective effects of the KD, providing a rationale for the implementation of dietary interventions as a therapeutic strategy for T2DM-induced dementia in the future.

The use of nomogram for detecting mild cognitive impairment in patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is highly prevalent worldwide and may lead to a higher rate of cognitive dysfunction. This study aimed to develop and validate a nomogram-based model to detect mild cognitive impairment (MCI) in T2DM patients.

METHODS

Inpatients with T2DM in the endocrinology department of Xiangya Hospital were consecutively enrolled between March and December 2021. Well-qualified investigators conducted face-to-face interviews with participants to retrospectively collect sociodemographic characteristics, lifestyle factors, T2DM-related information, and history of depression and anxiety. Cognitive function was assessed using the Mini-Mental State Examination scale. A nomogram was developed to detect MCI based on the results of the multivariable logistic regression analysis. Calibration, discrimination, and clinical utility of the nomogram were subsequently evaluated by calibration plot, receiver operating characteristic curve, and decision curve analysis, respectively.

RESULTS

A total of 496 patients were included in this study. The prevalence of MCI in T2DM patients was 34.1% (95% confidence interval [CI]: 29.9%-38.3%). Age, marital status, household income, diabetes duration, diabetic retinopathy, anxiety, and depression were independently associated with MCI. Nomogram based on these factors had an area under the curve of 0.849 (95% CI: 0.815-0.883), and the threshold probability ranged from 35.0% to 85.0%.

CONCLUSIONS

Almost one in three T2DM patients suffered from MCI. The nomogram, based on age, marital status, household income, duration of diabetes, diabetic retinopathy, anxiety, and depression, achieved an optimal diagnosis of MCI. Therefore, it could provide a clinical basis for detecting MCI in T2DM patients.

Exploration and Clinical Verification of the Blood Co-Expression Genes of Type 2 Diabetes Mellitus and Mild Cognitive Dysfunction in the Elderly

With the development of society, the incidence of dementia and type 2 diabetes (T2DM) in the elderly has been increasing. Although the correlation between T2DM and mild cognitive impairment (MCI) has been confirmed in the previous literature, the interaction mechanism remains to be clarified. To explore the co-pathogenic genes in the blood of MCI and T2DM patients, clarify the correlation between T2DM and MCI, achieve the purpose of early disease prediction, and provide new ideas for the prevention and treatment of dementia. We downloaded T2DM and MCI microarray data from GEO databases and identified the differentially expressed genes associated with MCI and T2DM. We obtained co-expressed genes by intersecting differentially expressed genes. Then, we performed GO and KEGG enrichment analysis of co-DEGs. Next, we constructed the PPI network and found the hub genes in the network. By constructing the ROC curve of hub genes, the most valuable genes for diagnosis were obtained. Finally, the correlation between MCI and T2DM was clinically verified by means of a current situation investigation, and the hub gene was verified by qRT-PCR. A total of 214 co-DEGs were selected, 28 co-DEGs were up-regulated, and 90 co-DEGs were down-regulated. Functional enrichment analysis showed that co-DEGs were mainly enriched in metabolic diseases and some signaling pathways. The construction of the PPI network identified the hub genes in MCI and T2DM co-expression genes. We identified nine hub genes of co-DEGs, namely LNX2, BIRC6, ANKRD46, IRS1, TGFB1, APOA1, PSEN1, NPY, and ALDH2. Logistic regression analysis and person correlation analysis showed that T2DM was correlated with MCI, and T2DM increased the risk of cognitive impairment. The qRT-PCR results showed that the expressions of LNX2, BIRC6, ANKRD46, TGFB1, PSEN1, and ALDH2 were consistent with the results of bioinformatic analysis. This study screened the co-expressed genes of MCI and T2DM, which may provide new therapeutic targets for the diagnosis and treatment of diseases.

Detecting type 2 diabetes mellitus cognitive impairment using whole-brain functional connectivity

Type 2 diabetes mellitus (T2DM) is closely linked to cognitive decline and alterations in brain structure and function. Resting-state functional magnetic resonance imaging (rs-fMRI) is used to diagnose neurodegenerative diseases, such as cognitive impairment (CI), Alzheimer's disease (AD), and vascular dementia (VaD). However, whether the functional connectivity (FC) of patients with T2DM and mild cognitive impairment (T2DM-MCI) is conducive to early diagnosis remains unclear. To answer this question, we analyzed the rs-fMRI data of 37 patients with T2DM and mild cognitive impairment (T2DM-MCI), 93 patients with T2DM but no cognitive impairment (T2DM-NCI), and 69 normal controls (NC). We achieved an accuracy of 87.91% in T2DM-MCI versus T2DM-NCI classification and 80% in T2DM-NCI versus NC classification using the XGBoost model. The thalamus, angular, caudate nucleus, and paracentral lobule contributed most to the classification outcome. Our findings provide valuable knowledge to classify and predict T2DM-related CI, can help with early clinical diagnosis of T2DM-MCI, and provide a basis for future studies.

Water intake, hydration status and 2-year changes in cognitive performance: a prospective cohort study

BACKGROUND

Water intake and hydration status have been suggested to impact cognition; however, longitudinal evidence is limited and often inconsistent. This study aimed to longitudinally assess the association between hydration status and water intake based on current recommendations, with changes in cognition in an older Spanish population at high cardiovascular disease risk.

METHODS

A prospective analysis was conducted of a cohort of 1957 adults (aged 55-75) with overweight/obesity (BMI between ≥ 27 and < 40 kg/m²) and metabolic syndrome from the PREDIMED-Plus study. Participants had completed bloodwork and validated, semiquantitative beverage and food frequency questionnaires at baseline, as well as an extensive neuropsychological battery of 8 validated tests at baseline and 2 years of follow-up. Hydration status was determined by serum osmolarity calculation and categorized as < 295 mmol/L (hydrated), 295-299.9 mmol/L (impending dehydration), and ≥ 300 mmol/L (dehydrated). Water intake was assessed as total drinking water intake and total water intake from food and beverages and according to EFSA recommendations. Global cognitive function was determined as a composite z-score summarizing individual participant results from all neuropsychological tests. Multivariable linear regression models were fitted to assess the associations between baseline hydration status and fluid intake, continuously and categorically, with 2-year changes in cognitive performance.

RESULTS

The mean baseline daily total water intake was 2871 ± 676 mL/day (2889 ± 677 mL/day in men; 2854 ± 674 mL/day in women), and 80.2% of participants met the ESFA reference values for an adequate intake. Serum osmolarity (mean 298 ± 24 mmol/L, range 263 to 347 mmol/L) indicated that 56% of participants were physiologically dehydrated. Lower physiological hydration status (i.e., greater serum osmolarity) was associated with a greater decline in global cognitive function z-score over a 2-year period (β: - 0.010; 95% CI - 0.017 to - 0.004, p-value = 0.002). No significant associations were observed between water intake from beverages and/or foods with 2-year changes in global cognitive function.

CONCLUSIONS

Reduced physiological hydration status was associated with greater reductions in global cognitive function over a 2-year period in older adults with metabolic syndrome and overweight or obesity. Future research assessing the impact of hydration on cognitive performance over a longer duration is needed.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Registry, ISRCTN89898870. Retrospectively registered on 24 July 2014.

Advances of H2S in Regulating Neurodegenerative Diseases by Preserving Mitochondria Function

Neurotoxicity is induced by different toxic substances, including environmental chemicals, drugs, and pathogenic toxins, resulting in oxidative damage and neurodegeneration in mammals. The nervous system is extremely vulnerable to oxidative stress because of its high oxygen demand. Mitochondria are the main source of ATP production in the brain neuron, and oxidative stress-caused mitochondrial dysfunction is implicated in neurodegenerative diseases. H2S was initially identified as a toxic gas; however, more recently, it has been recognized as a neuromodulator as well as a neuroprotectant. Specifically, it modulates mitochondrial activity, and H2S oxidation in mitochondria produces various reactive sulfur species, thus modifying proteins through sulfhydration. This review focused on highlighting the neuron modulation role of H2S in regulating neurodegenerative diseases through anti-oxidative, anti-inflammatory, anti-apoptotic and S-sulfhydration, and emphasized the importance of H2S as a therapeutic molecule for neurological diseases.

Which Multivariate Multi-Scale Entropy Algorithm Is More Suitable for Analyzing the EEG Characteristics of Mild Cognitive Impairment?

So far, most articles using the multivariate multi-scale entropy algorithm mainly use algorithms to analyze the multivariable signal complexity without clearly describing what characteristics of signals these algorithms measure and what factors affect these algorithms. This paper analyzes six commonly used multivariate multi-scale entropy algorithms from a new perspective. It clarifies for the first time what characteristics of signals these algorithms measure and which factors affect them. It also studies which algorithm is more suitable for analyzing mild cognitive impairment (MCI) electroencephalograph (EEG) signals. The simulation results show that the multivariate multi-scale sample entropy (mvMSE), multivariate multi-scale fuzzy entropy (mvMFE), and refined composite multivariate multi-scale fuzzy entropy (RCmvMFE) algorithms can measure intra- and inter-channel correlation and multivariable signal complexity. In the joint analysis of coupling and complexity, they all decrease with the decrease in signal complexity and coupling strength, highlighting their advantages in processing related multi-channel signals, which is a discovery in the simulation. Among them, the RCmvMFE algorithm can better distinguish different complexity signals and correlations between channels. It also performs well in anti-noise and length analysis of multi-channel data simultaneously. Therefore, we use the RCmvMFE algorithm to analyze EEG signals from twenty subjects (eight control subjects and twelve MCI subjects). The results show that the MCI group had lower entropy than the control group on the short scale and the opposite on the long scale. Moreover, frontal entropy correlates significantly positively with the Montreal Cognitive Assessment score and Auditory Verbal Learning Test delayed recall score on the short scale.

Diabetes and cognitive function: An evidence-based current perspective

Several epidemiological studies have clearly identified diabetes mellitus (DM) as a major risk factor for cognitive dysfunction, and it is going to be a major public health issue in the coming years because of the alarming rise in diabetes prevalence across the world. Brain and neural tissues predominantly depend on glucose as energy substrate and hence, any alterations in carbohydrate meta-bolism can directly impact on cerebral functional output including cognition, executive capacity, and memory. DM affects neuronal function and mental capacity in several ways, some of which include hypoperfusion of the brain tissues from cerebrovascular disease, diabetes-related alterations of glucose transporters causing abnormalities in neuronal glucose uptake and metabolism, local hyper- and hypometabolism of brain areas from insulin resistance, and recurrent hypoglycemic episodes inherent to pharmacotherapy of diabetes resulting in neuronal damage. Cognitive decline can further worsen diabetes care as DM is a disease largely self-managed by patients. Therefore, it is crucial to understand the pathobiology of cognitive dysfunction in relation to DM and its management for optimal long-term care plan for patients. A thorough appraisal of normal metabolic characteristics of the brain, how alterations in neural metabolism affects cognition, the diagnostic algorithm for patients with diabetes and dementia, and the management and prognosis of patients when they have this dangerous combination of illnesses is imperative in this context. This evidence-based narrative with the back-up of latest clinical trial reviews elaborates the current understanding on diabetes and cognitive function to empower physicians to manage their patients in day-to-day clinical practice.

Cognitive impairment with Type 2 Diabetes Mellitus among community-dwelling older adults in Chile: Prevalence, risk factors and cognitive characteristics

Introduction

The aim of this study is to determine prevalence and risk factors of Cognitive Impairment (CI) and its association with Type 2 Diabetes Mellitus (T2DM) in subjects aged 65 years and above. Additionally, we attempt to provide a cognitive profile for T2DM group.

Methodology

A cross-sectional analytical study to assess CI was carried out. We evaluated a sample of community-dwelling residents from Chile. All participants underwent a general interview, lifestyle questionnaires and a comprehensive neuropsychological battery. Regression analyses were performed to evaluate risk of CI with T2DM and influencing factors. Results between groups in the different domains of the neuropsychological assessment were compared by Student's t-tests and MANOVA.

Results

Among all 358 subjects, overall T2DM prevalence were 17.3%. The prevalence of CI was higher in T2DM group compared to the healthy participants (30.7%, p < 0.001). The risk of CI was 2.8 times higher in older people with T2DM compared to older people without the diagnosis. Multiple regression analysis, adjusted for age and gender, demonstrated that age, education, presence of dyslipidemia, and T2DM duration were the predictor variables significantly associated with CI. T2DM group performed worse on global cognitive performance, attention, language, verbal memory, visual memory, visual constructional ability, and executive function. After adjusting for significant covariates from multiple regression analysis, a relationship between "cognition" and T2DM is still observed. Amnesic multi-domain impairment was the specific cognitive identified pattern for T2DM group.

Conclusion

The present study confirms the high prevalence of CI with T2DM among Chilean older adults in a community-based population. T2DM is significantly associated with a higher risk of CI, and age, education, presence of dyslipidemia, and duration of T2DM are risk factors. T2DM patients with CI are impaired in multiple cognitive domains, even after adjusting covariables, resulting in an amnesic multi-domain cognitive profile.

Oxidative stress: The nexus of obesity and cognitive dysfunction in diabetes

Obesity has been associated with oxidative stress. Obese patients are at increased risk for diabetic cognitive dysfunction, indicating a pathological link between obesity, oxidative stress, and diabetic cognitive dysfunction. Obesity can induce the biological process of oxidative stress by disrupting the adipose microenvironment (adipocytes, macrophages), mediating low-grade chronic inflammation, and mitochondrial dysfunction (mitochondrial division, fusion). Furthermore, oxidative stress can be implicated in insulin resistance, inflammation in neural tissues, and lipid metabolism disorders, affecting cognitive dysfunction in diabetics.