Cognitive impairment and dementia: a new emerging complication of type 2 diabetes-The diabetologist's perspective

Artificial intelligence for diabetes care: current and future prospects

Artificial intelligence (AI) use in diabetes care is increasingly being explored to personalise care for people with diabetes and adapt treatments for complex presentations. However, the rapid advancement of AI also introduces challenges such as potential biases, ethical considerations, and implementation challenges in ensuring that its deployment is equitable. Ensuring inclusive and ethical developments of AI technology can empower both health-care providers and people with diabetes in managing the condition. In this Review, we explore and summarise the current and future prospects of AI across the diabetes care continuum, from enhancing screening and diagnosis to optimising treatment and predicting and managing complications.

Exploring galectin-3's role in predicting mild cognitive impairment in type 2 diabetes and its regulation by miRNAs

Objective

This study aimed to investigate the role of galectin-3 (Gal-3; coded by LGALS3 gene), as a biomarker for MCI in T2DM patients and to develop and validate a predictive nomogram integrating galectin-3 with clinical risk factors for MCI prediction. Additionally, microRNA regulation of LGALS3 was explored.

Methods

The study employed a cross-sectional design. A total of 329 hospitalized T2DM patients were recruited and randomly allocated into a training cohort (n = 231) and a validation cohort (n = 98) using 7:3 ratio. Demographic data and neuropsychological assessments were recorded for all participants. Plasma levels of galectin-3 were measured using ELISA assay. We employed Spearman's correlation and multivariable linear regression to analyze the relationship between galectin-3 levels and cognitive performance. Furthermore, univariate and multivariate logistic regression analyses were conducted to identify independent risk factors for MCI in T2DM patients. Based on these analyses, a predictive nomogram incorporating galectin-3 and clinical predictors was developed. The model's performance was evaluated in terms of discrimination, calibration, and clinical utility. Regulatory miRNAs were identified using bioinformatics and their interactions with LGALS3 were confirmed through qRT-PCR and luciferase reporter assays.

Results

Galectin-3 was identified as an independent risk factor for MCI, with significant correlations to cognitive decline in T2DM patients. The developed nomogram, incorporating Gal-3, age, and education levels, demonstrated excellent predictive performance with an AUC of 0.813 in the training cohort and 0.775 in the validation cohort. The model outperformed the baseline galectin-3 model and showed a higher net benefit in clinical decision-making. Hsa-miR-128-3p was significantly downregulated in MCI patients, correlating with increased Gal-3 levels, while Luciferase assays confirmed miR-128-3p's specific binding and influence on LGALS3.

Conclusion

Our findings emphasize the utility of Gal-3 as a viable biomarker for early detection of MCI in T2DM patients. The validated nomogram offers a practical tool for clinical decision-making, facilitating early interventions to potentially delay the progression of cognitive impairment. Additionally, further research on miRNA128's regulation of Gal-3 levels is essential to substantiate our results.

Semaglutide Attenuates Anxious and Depressive-Like Behaviors and Reverses the Cognitive Impairment in a Type 2 Diabetes Mellitus Mouse Model Via the Microbiota-Gut-Brain Axis

Newly conducted research suggests that metabolic disorders, like diabetes and obesity, play a significant role as risk factors for psychiatric disorders. This connection presents a potential avenue for creating novel antidepressant medications by repurposing drugs originally developed to address antidiabetic conditions. Earlier investigations have shown that GLP-1 (Glucagon-like Peptide-1) analogs exhibit neuroprotective qualities in various models of neurological diseases, encompassing conditions such as Alzheimer's disease, Parkinson's disease, and stroke. Moreover, GLP-1 analogs have demonstrated the capability to enhance neurogenesis, a process recognized for its significance in memory formation and the cognitive and emotional aspects of information processing. Nonetheless, whether semaglutide holds efficacy as both an antidepressant and anxiolytic agent remains uncertain. To address this, our study focused on a mouse model of depression linked to type 2 diabetes induced by a High Fat Diet (HFD). In this model, we administered semaglutide (0.05 mg/Kg intraperitoneally) on a weekly basis to evaluate its potential as a therapeutic option for depression and anxiety. Diabetic mice had higher blood glucose, lipidic profile, and insulin resistance. Moreover, mice fed HFD showed higher serum interleukin (IL)-1β and lipopolysaccharide (LPS) associated with impaired humor and cognition. The analysis of behavioral responses revealed that the administration of semaglutide effectively mitigated depressive- and anxiety-like behaviors, concurrently demonstrating an enhancement in cognitive function. Additionally, semaglutide treatment protected synaptic plasticity and reversed the hippocampal neuroinflammation induced by HFD fed, improving activation of the insulin pathway, demonstrating the protective effects of semaglutide. We also found that semaglutide treatment decreased astrogliosis and microgliosis in the dentate gyrus region of the hippocampus. In addition, semaglutide prevented the DM2-induced impairments of pro-opiomelanocortin (POMC), and G-protein-coupled receptor 43 (GPR43) and simultaneously increased the NeuN + and Glucagon-like Peptide-1 receptor (GLP-1R+) neurons in the hippocampus. Our data also showed that semaglutide increased the serotonin (5-HT) and serotonin transporter (5-HTT) and glutamatergic receptors in the hippocampus. At last, semaglutide changed the gut microbiota profile (increasing Bacterioidetes, Bacteroides acidifaciens, and Blautia coccoides) and decreased leaky gut, improving the gut-brain axis. Taken together, semaglutide has the potential to act as a therapeutic tool for depression and anxiety.

Navigating the intersection: Diabetes and Alzheimer's intertwined relationship

Alzheimer's disease (AD) and Diabetes mellitus (DM) exhibit comparable pathophysiological pathways. Genetic abnormalities in APP, PS-1, and PS-2 are linked to AD, with diagnostic aid from CSF and blood biomarkers. Insulin dysfunction, termed "type 3 diabetes mellitus" in AD, involves altered insulin signalling and neuronal shrinkage. Insulin influences beta-amyloid metabolism, exacerbating neurotoxicity in AD and amyloid production in DM. Both disorders display impaired glucose transporter expression, hastening cognitive decline. Mitochondrial dysfunction and Toll-like receptor 4-mediated inflammation worsen neurodegeneration in both diseases. ApoE4 raises disease risk, especially when coupled with dyslipidemia common in DM. Targeting shared pathways like insulin-degrading enzyme activation and HSP60 holds promise for therapeutic intervention. Recognizing these interconnected mechanisms underscores the imperative for developing tailored treatments addressing the overlapping pathophysiology of AD and DM, offering potential avenues for more effective management of both conditions.

Artificial Intelligence Applications in Diabetic Retinopathy: What We Have Now and What to Expect in the Future

Diabetic retinopathy (DR) is a major complication of diabetes mellitus and is a leading cause of vision loss globally. A prompt and accurate diagnosis is crucial for ensuring favorable visual outcomes, highlighting the need for increased access to medical care. The recent remarkable advancements in artificial intelligence (AI) have raised high expectations for its role in disease diagnosis and prognosis prediction across various medical fields. In addition to achieving high precision comparable to that of ophthalmologists, AI-based diagnosis of DR has the potential to improve medical accessibility, especially through telemedicine. In this review paper, we aim to examine the current role of AI in the diagnosis of DR and explore future directions.

Cognitive Profile and Cardiovascular Risk Factors in Older Adults with Mild Cognitive Impairment

The prevalence of cardiovascular risk factors (CVRFs) in the older adults population and their specific impact on their cognitive profiles still requires further research. For this purpose, a cross-sectional study was carried out to describe the presence of CVRFs and their association with cognitive performance in a sample of older adults (65-85 years old) with Mild Cognitive Impairment (MCI). Participants (n = 185) were divided into three groups concerning their cardiovascular risk level determined by the presence of different CVRFs, including Type 2 Diabetes (T2D), dyslipidemia, hypertension, and obesity. The primary outcome measures were the participant's scores in the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Sociodemographic, clinical, and psychosocial data were collected. Non-parametrical statistical analyses and effect sizes were calculated. Findings revealed that a greater presence of CVRFs was not associated with a worse overall cognitive performance. High-risk patients were more likely to have significantly worse performance in the attentional domain compared to medium-risk (p = 0.029, r = 0.42) and compared to low-risk (p = 0.041, r = 0.35), specifically in the digits repetition subtest (p = 0.042). T2D alone was the CVRF associated with cognitive differences (p = 0.037, r = 0.32), possibly mediated by the duration of the condition. Consequently, a higher presence of CVRFs did not lead to a worse overall cognitive performance. However, high-risk individuals were more likely to experience cognitive impairment, particularly in the attentional domain. T2D played a significant role in these cognitive profile differences, possibly influenced by its duration.

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.

The usefulness of the retina for identifying people with type 2 diabetes with prodromal stages of dementia

Type 2 diabetes (T2D) is associated with cognitive impairment and dementia. The detection of cognitive impairment is important because this population is at higher risk of experiencing difficulties in the self-management of diabetes. Mild cognitive impairment (MCI) often remains undiagnosed due to lack of simple tools for screening at large scale. This represents an important gap in the patients' management because subjects with diabetes and MCI are at high risk of progressing to dementia. Due to its developmental origin as a brain-derived tissue, the retina has been proposed as a potential means of non-invasive and readily accessible exploration of brain pathology. Recent evidence showed that retinal imaging and/or functional tests are correlated with the cognitive function and brain changes in T2D. Simple retinal functional tests (i.e. retinal microperimetry) have proven to be useful as reliable tool for the cognitive evaluation and monitoring in patients with T2D>65 years. This review gives an overall update on the usefulness of retinal imaging in identifying patients with T2D at risk of developing dementia.

Metformin, Cognitive Function, and Changes in the Gut Microbiome

The decline in cognitive function and the prevalence of neurodegenerative disorders are among the most serious threats to health in old age. The prevalence of dementia has reached 50 million people worldwide and has become a major public health problem. The causes of age-related cognitive impairment are multiple, complex, and difficult to determine. However, type 2 diabetes (T2D) is linked to an enhanced risk of cognitive impairment and dementia. Human studies have shown that patients with T2D exhibit dysbiosis of the gut microbiota. This dysbiosis may contribute to the development of insulin resistance and increased plasma lipopolysaccharide concentrations. Metformin medication mimics some of the benefits of calorie restriction and physical activity, such as greater insulin sensitivity and decreased cholesterol levels, and hence may also have a positive impact on aging in humans. According to recent human investigations, metformin might partially restore gut dysbiosis related to T2D. Likewise, some studies showed that metformin reduced the risk of dementia and improved cognition, although not all studies are concordant. Therefore, this review focused on those human studies describing the effects of metformin on the gut microbiome (specifically the changes in taxonomy, function, and circulating metabolomics), the changes in cognitive function, and their possible bidirectional implications.

SGLT2 Inhibitor Canagliflozin Alleviates High Glucose-Induced Inflammatory Toxicity in BV-2 Microglia

Patients with diabetes mellitus can experience hyperglycemia, which affects brain function and produces cognitive impairment or neurodegeneration. Neuroinflammation is an important cause of cognitive dysfunction. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are antihyperglycemic agents that reportedly possess anti-inflammatory properties and may produce beneficial cognitive effects. We hypothesized that SGLT2 inhibitors alleviate hyperglycemia-related inflammation in brain immune cells. Cultured BV-2 microglia were exposed to high glucose (HG) in the absence or presence of SGLT2 inhibitors including canagliflozin (Cana), dapagliflozin (Dapa), empagliflozin (Empa), and ertugliflozin (Ertu). Afterward, we evaluated the cytotoxic and inflammatory responses by specific biochemical assays. Treatments with non-toxic Cana or Dapa, but not Empa or Ertu, inhibited proliferation without cell death. Only Cana rescued BV-2 microglia from HG-induced cytotoxicity, including apoptosis or autophagic degradation. None of SGLT2 inhibitors affected the HG-stimulated induction of stress proteins HO-1 and HSP70. Also, compared to the other three SGLT2 inhibitors, Cana was better at inhibiting HG-induced oxidative/inflammatory stress, as evidenced by its ability to repress proinflammatory factors (e.g., oxygen free radicals, iNOS, NLRP3, IL-1β, and TNF-α) other than COX-2. Cana's action to alleviate HG insults was mediated not by altering SGLT2 protein expression, but by reducing HG-stimulated signaling activities of NFκB, JNK, p38, and PI3K/Akt pathways. Particularly, Cana imitated the effects of NFκB inhibitor on HG-induced iNOS and COX-2. Of the four SGLT2 inhibitors, Cana provided BV-2 microglia with the best protection against HG-induced inflammatory toxicity. Thus, Cana may help to reduce innate neuroimmune damage caused by hyperglycemia.

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.

Glucose Transport and Utilization in the Hippocampus: From Neurophysiology to Diabetes-Related Development of Dementia

The association of diabetes with cognitive dysfunction has at least 60 years of history, which started with the observation that children with type 1 diabetes mellitus (T1D), who had recurrent episodes of hypoglycemia and consequently low glucose supply to the brain, showed a deficit of cognitive capacity. Later, the growing incidence of type 2 diabetes mellitus (T2D) and dementia in aged populations revealed their high association, in which a reduced neuronal glucose supply has also been considered as a key mechanism, despite hyperglycemia. Here, we discuss the role of glucose in neuronal functioning/preservation, and how peripheral blood glucose accesses the neuronal intracellular compartment, including the exquisite glucose flux across the blood-brain barrier (BBB) and the complex network of glucose transporters, in dementia-related areas such as the hippocampus. In addition, insulin resistance-induced abnormalities in the hippocampus of obese/T2D patients, such as inflammatory stress, oxidative stress, and mitochondrial stress, increased generation of advanced glycated end products and BBB dysfunction, as well as their association with dementia/Alzheimer's disease, are addressed. Finally, we discuss how these abnormalities are accompained by the reduction in the expression and translocation of the high capacity insulin-sensitive glucose transporter GLUT4 in hippocampal neurons, which leads to neurocytoglycopenia and eventually to cognitive dysfunction. This knowledge should further encourage investigations into the beneficial effects of promising therapeutic approaches which could improve central insulin sensitivity and GLUT4 expression, to fight diabetes-related cognitive dysfunctions.

Association of cognitive impairment and diabetes on survival in Chinese older people with hypertension: a 10-year prospective study

BACKGROUND

Older people with hypertension may have more complex multisystem problems and a higher risk of morbidity and mortality. We aimed to examine the association of cognitive impairment (CI) and diabetes mellitus (DM) on all-cause mortality in the aged with hypertension (HTN).

METHODS

This is a prospective cohort study with a sample of 1017 older people with hypertension aged 60 years or older who completed baseline examinations in 2009-2010 and followed up for ten years in 2020. The endpoint was death from any cause. Subjects were categorized as HTN only, HTN + DM, HTN + CI, and HTN + DM + CI. Cox regression model was used to determine the association of comorbidities on all-cause mortality.

RESULTS

During the 10-year follow-up period, 196 deaths occurred. After adjusted for covariates, risk of death from any cause was significantly increased in the older people with increased comorbidities (P = 0.003). Compared with the HTN only, with HTN + CI, and HTN + DM + CI, the HRs (95% confidence intervals) for all-cause mortality were 1.61(1.13-2.30) and 1.79(1.07-2.99), respectively. In stratified analyses, the relationship between comorbidities level and the risk of all-cause mortality persisted.

CONCLUSION

All-cause mortality risks increased with increasing the comorbidities. This study emphasizes the importance of comprehensive management of the older people with HTN in clinical practice and public health policy.

Diabetic Retinopathy and Dementia Association, Beyond Diabetes Severity

PURPOSE

To investigate whether associations between diabetic retinopathy (DR) and dementia and Alzheimer's disease (AD) remain significant after controlling for several measures of diabetes severity.

DESIGN

Retrospective cohort study.

METHODS

Adult Changes in Thought (ACT) is a prospective cohort study of adults aged ≥65 years, randomly selected and recruited from the membership rolls of Kaiser Permanente Washington, who are dementia free at enrollment and followed biennially until incident dementia. The ACT participants were included in this study if they had type 2 diabetes mellitus at enrollment or developed it during follow-up, and data were collected through September, 2018 (3516 person-years of follow-up). Diabetes was defined by ≥ 2 diabetes medication fills in 1 year. Diagnosis of DR was based on International Classification of Diseases Ninth and Tenth Revision codes. Estimates of microalbuminuria, long-term glycemia, and renal function from longitudinal laboratory records were used as indicators of diabetes severity. Alzheimer's disease and dementia were diagnosed using research criteria at expert consensus meetings.

RESULTS

A total of 536 participants (median baseline age 75 [interquartile range 71-80], 54% women) met inclusion criteria. Significant associations between DR >5 years duration with dementia (hazard ratio 1.81 [95% CI 1.23, 2.65]) and AD (1.80 [1.15, 2.82]) were not altered by adjustment for estimates of microalbuminuria, long-term glycemia, and renal function (dementia: 1.69 [1.14, 2.50]; AD: 1.73 [1.10, 2.74]).

CONCLUSIONS

Among people with type 2 diabetes, DR itself appears to be an important biomarker of dementia risk in addition to glycemia and renal complications.

Postmortem Brains from Subjects with Diabetes Mellitus Display Reduced GLUT4 Expression and Soma Area in Hippocampal Neurons: Potential Involvement of Inflammation

Diabetes mellitus (DM) is an important risk factor for dementia, which is a common neurodegenerative disorder. DM is known to activate inflammation, oxidative stress, and advanced glycation end products (AGEs) generation, all capable of inducing neuronal dysfunctions, thus participating in the neurodegeneration progress. In that process, disturbed neuronal glucose supply plays a key role, which in hippocampal neurons is controlled by the insulin-sensitive glucose transporter type 4 (GLUT4). We investigated the expression of GLUT4, nuclear factor NF-kappa B subunit p65 [NFKB (p65)], carboxymethyllysine and synapsin1 (immunohistochemistry), and soma area in human postmortem hippocampal samples from control, obese, and obese+DM subjects (41 subjects). Moreover, in human SH-SY5Y neurons, tumor necrosis factor (TNF) and glycated albumin (GA) effects were investigated in GLUT4, synapsin-1 (SYN1), tyrosine hydroxylase (TH), synaptophysin (SYP) proteins, and respective genes; NFKB binding activity in the SLC2A4 promoter; effects of increased histone acetylation grade by histone deacetylase 3 (HDAC3) inhibition. Hippocampal neurons (CA4 area) of obese+DM subjects displayed reduced GLUT4 expression and neuronal soma area, associated with increased expression of NFKB (p65). Challenges with TNF and GA decreased the SLC2A4/GLUT4 expression in SH-SY5Y neurons. TNF decreased SYN1, TH, and SYP mRNAs and respective proteins, and increased NFKB binding activity in the SLC2A4 promoter. Inhibition of HDAC3 increased the SLC2A4 expression and the total neuronal content of CRE-binding proteins (CREB/ICER), and also counterbalanced the repressor effect of TNF upon these parameters. This study revealed reduced postmortem human hippocampal GLUT4 content and neuronal soma area accompanied by increased proinflammatory activity in the brains of DM subjects. In isolated human neurons, inflammatory activation by TNF reduced not only the SLC2A4/GLUT4 expression but also the expression of some genes related to neuronal function (SYN1, TH, SYP). These effects may be related to epigenetic regulations (H3Kac and H4Kac status) since they can be counterbalanced by inhibiting HDAC3. These results uncover the improvement in GLUT4 expression and/or the inhibition of HDAC3 as promising therapeutic targets to fight DM-related neurodegeneration.

Synergistic Effects of Nigella sativa and Exercise on Diabetic Profiles: A Systematic Review

Individually, Nigella sativa (NS) and physical training interventions have been shown to be effective preventive and therapeutic strategies for diabetes mellitus. However, the effect of these in combination on bioindicators of diabetes has not yet been evaluated; there is little information available in the literature. A systematic review was therefore performed to assess any mutually potentiating impacts of NS and physical training interventions in diabetic subjects. A search was performed on this topic in the PubMed, CINAHL, Google Scholar and Web of Science databases for randomised, quasi-randomised or non-randomised controlled trials, studies with factorial or single-cohort pre-post designs, case series as well as case reports. The search terms encompassed various combinations of the following: "exercise", "training", "physical activity", "NS", "treadmill", "swimming", "Thymoquinone", "Nigellone", "caraway oil" and "black seeds". Two reviewers screened the abstracts of 202 identified publications according to predetermined inclusion criteria-i.e. papers published from 2009 onwards in the English language, studies on human or animal subjects, and the assessment of diabetic bioindicators following the combined administration of NS and exercise regimens in comparison with just one of these interventions or against controls. Despite the rich data available regarding the effect of both interventions separately, two human studies and two animal studies were ultimately included in the review. However, the benefit of combined administration of NS and exercise regimens on glycemic and lipidemic control was much more obvious compared to exercise alone. In conclusion, these findings suggested that combined administration of NS and exercise regimens could be used as an effective adjuvant for oral antidiabetic drugs in diabetes control.

ZiBuPiYin recipe ameliorates diabetes-associated cognitive decline by improving neuronal mitochondrial function in chronic psychologically stressed zucker diabetic fatty rats

ETHNOPHARMACOLOGICAL RELEVANCE

Zibu Piyin Recipe (ZBPYR) is a traditional Chinese medicine compound composed of 12 kinds of Chinese herbal medicines including red ginseng and yam. Long-term basic and clinical applications have proved that ZBPYR can prevent and treat cognitive dysfunction. Previous studies showed that chronic psychological stress can increase the risk of type 2 diabetes mellitus (T2DM), and lead to cognitive decline. Mitochondrial dysfunction plays a key role in chronic psychological stress-induced diabetes mellitus. While the mechanism of mitochondrial dysfunction and insulin resistance in diabetes-associated cognitive decline (DACD) is unclear.

AIM OF THE STUDY

Our previous research found that a ZiBuPiYin recipe (ZBPYR) has significant pharmacological effects against DACD. The present study investigated changes in mitochondrial dysfunction in the brain and the mechanism of insulin resistance and mitochondrial damage to explore the relationship between neuronal mitochondrial dysfunction and insulin resistance in chronic psychologically stressed DACD rats.

MATERIALS AND METHODS

Zucker diabetic fatty (ZDF) rats with spontaneous T2DM and rats with diabetic cognitive impairment that was induced by chronic psychological stress were used in in vivo experiments. PC12 cells that were damaged by rotenone were used for the in vitro experiment.

RESULTS

The findings indicated that the number of mitochondria decreased, morphology and membrane potential were damaged, and reactive oxygen species increased in the cortex and hippocampus in psychologically stressed DACD rats. Protein kinase Cβ2 (PKCβ2) activation and insulin resistance were markedly induced by chronic psychological stress, together with decreases in peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) and mitochondrial fusion protein 2 (Mfn2). Furthermore, ZBPYR exerted protective effects both in in vivo and in vitro.

CONCLUSION

Mitochondrial damage and insulin resistance were observed in the brain in chronic psychologically stressed DACD rats. The ZBPYR significantly improved brain mitochondrial damage and insulin resistance in chronic psychologically stressed DACD rats. These results provide novel insights for the development of ZBPYR as a traditional Chinese medicine for the treatment of chronic psychological stress and DACD.

Cognitive Function and Self-Management Behaviors in Older Adults With Type 2 Diabetes

BACKGROUND

Type 2 diabetes (T2D) is strongly associated with cognitive impairment. Decreased cognitive function could affect daily self-management behaviors critical for people with T2D. Executive function is significant for daily self-management, and decreased subjective cognitive function could be an early indicator of poor daily self-management. However, little is known about whether executive or subjective cognitive function affects daily self-management behaviors in older adults.

OBJECTIVES

We investigated the effect of executive function or subjective cognitive function on daily self-management behaviors (diet, glucose management, physical activity, and physician contact) in older adults with T2D.

METHODS

We used a cross-sectional, observational design with convenience sampling of 84 adults aged ≥60 years with T2D. Telephone-administered cognitive function tests measured participants' overall cognitive and executive function levels. Subjective cognitive function, diabetes self-management, and covariates, including demographic information (age, gender, race/ethnicity, and level of education), body mass index, depressive symptoms, and diabetes duration, were assessed using online surveys. Data were analyzed using bivariate correlation and backward stepwise regression.

RESULTS

The mean age of the sample was 68.46 ± 5.41 years. Participants were predominantly female and White, and the majority had normal cognitive function. Controlling for demographics, body mass index, depressive symptoms, and diabetes duration, a decrease in executive function indicated by a greater number of errors made during the telephone-administered Oral Trail Making Test Part B relative to the sample was associated with poorer adherence to physician contact behaviors. Subjective cognitive function was not associated with any self-management behaviors.

DISCUSSION

A reduction in executive function was associated with poorer adherence to physician contact behaviors in older adults with T2D and normal cognitive function; lack of adherence to physician contact behaviors could be an early indicator of declining cognitive function. Difficulties or changes in routine diabetes self-management behaviors should be closely monitored in older adults. Cognitive assessment should be followed when needed.

Genome-Wide Mapping Implicates 5-Hydroxymethylcytosines in Diabetes Mellitus and Alzheimer's Disease

BACKGROUND

Diabetes mellitus (DM) is a recognized risk factor for dementia. Because DM is a potentially modifiable condition, greater understanding of the mechanisms linking DM to the clinical expression of Alzheimer's disease dementia may provide insights into much needed dementia therapeutics.

OBJECTIVE

In this feasibility study, we investigated DM as a dementia risk factor by examining genome-wide distributions of the epigenetic DNA modification 5-hydroxymethylcytosine (5hmC).

METHODS

We obtained biologic samples from the Rush Memory and Aging Project and used the highly sensitive 5hmC-Seal technique to perform genome-wide profiling of 5hmC in circulating cell-free DNA (cfDNA) from antemortem serum samples and in genomic DNA from postmortem prefrontal cortex brain tissue from 80 individuals across four groups: Alzheimer's disease neuropathologically defined (AD), DM clinically defined, AD with DM, and individuals with neither disease (controls).

RESULTS

Distinct 5hmC signatures and biological pathways were enriched in persons with both AD and DM versus AD alone, DM alone, or controls, including genes inhibited by EGFR signaling in oligodendroglia and those activated by constitutive RHOA. We also demonstrate the potential diagnostic value of 5hmC profiling in circulating cfDNA. Specifically, an 11-gene weighted model distinguished AD from non-AD/non-DM controls (AUC = 91.8%; 95% CI, 82.9-100.0%), while a 4-gene model distinguished DM-associated AD from AD alone (AUC = 87.9%; 95% CI, 77.5-98.3%).

CONCLUSION

We demonstrate in this small sample, the feasibility of detecting and characterizing 5hmC in DM-associated AD and of using 5hmC information contained in circulating cfDNA to detect AD in high-risk individuals, such as those with diabetes.

Cognitive Performance and Diabetic Retinopathy: What Your Eyes Can Reveal About Your Brain

BACKGROUND

Diabetic retinopathy (DR) is a chronic diabetes complication. People with Type 2 Diabetes Mellitus (T2DM) have two times the risk for dementia, suggesting it is a new chronic diabetes complication.

OBJECTIVE

Evaluate the association of DR with cognitive performance in a T2DM population.

METHODS

Cross-sectional study with 400 T2DM adults from whom socio-demographic, clinical, laboratory data were collected, and screening test for depression symptoms (Patient Health Questionaire- 9 (PHQ-9)), Mini-Mental State Examination (MMSE), Semantic Verbal Fluency Test, Trail Making Test A and B, Word Memory test were performed. All cognitive test scores were converted into Global Cognition z-Score (GCS(z)). The association between GCS(z) < 0 with DR was performed using a multivariate binary logistic regression model adjusted for age ≥ 65 years, school years ≤ 6 years, DM duration ≥ 10 years, depression symptoms score > 9 at PHQ-9, arterial hypertension, physical activity, diabetic retinopathy, macular edema, and cardiovascular disease.

RESULTS

After exclusions, the 251 eligible patients were 56.6% female, with a mean age of 61.1 (±9.8) years, DM duration of 12.6 (±8.9) years, and 7.6 (±4.2) years of school education. DR prevalence was 46.5%. Multivariate Logistic Regression Model showed an association between DR and GCS(z) < 0, with odds ratio (CI95%) of 2.50 (1.18-5.34), adjusted for age, low education level, arterial hypertension and depression symptoms (OD and CI95% respectively: 5.46(2.42-12.34); 12.19 (5.62-26.46); 2.55 (0.88-7.39); 3.53 (1.55-8.07)).

CONCLUSION

In this T2DM population, having DR increased the chance for worse cognitive performance even when adjusted for age, low education level, presence of arterial hypertension, and depression symptoms.

Alterations of peripheral cytokines, BDNF, and surface-based morphometry indices in T2DM patients without cognitive impairment

Purpose

This study aimed to investigate potential biological mechanisms underlying cognitive function alterations in Type 2 diabetes mellitus (T2DM) patients by integrating cortical morphology with peripheral cytokine levels and brain-derived neurotrophic factor (BDNF) levels, and to offer potential insights for the early detection of T2DM-related cognitive impairment.

Methods

This study included 16 T2DM patients with a Montreal Cognitive Assessment (MoCA) score of at least 26 points, as well as 16 healthy controls with normal cognitive function. The participants also completed the digit span test and digit symbol substitution test. Participants' serum levels of Interleukin 4 (IL-4), IL-6, IL-10, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and BDNF were also examined. Each subject underwent a high-resolution 3T structural brain MRI scan. Based on the aparc. a2009s atlas, we calculated the cortical thickness, sulcus depth, gyrification index, and fractal dimension for each participant using surface-based morphometry (SBM). Correlation analysis between cognitive measures, serum levels of cytokines and BDNF, and SBM indices were further performed.

Results

The levels of IL-4 and BDNF showed significant group differences. In the T2DM group, the sulcus depth exhibited a significant decrease in the left transverse frontopolar gyri and sulci, as well as in the right pole-occipital; the fractal dimension showed a significant increase in the right posterior-dorsal part of the cingulate gyrus; and the gyrification index significantly increased in the left inferior part of the precentral sulcus and right triangular part of the inferior frontal gyrus. Correlation analysis revealed a significant positive correlation between IL-10 levels and the sulcus depth of left transverse frontopolar gyri and sulci; a significant positive correlation between the sulcus depth of the right pole-occipital and the digit span test-forward scores, and a significant negative correlation between the gyrification index of the left inferior part of the precentral sulcus and the digit span test-backward scores among T2DM participants.

Conclusion

T2DM patients without cognitive impairment displayed reductions in IL 4 and BDNF levels, as well as significant alterations in their SBM indices, indicating that prior to the emergence of cognitive impairment, the SBM indices, peripheral cytokines, and BDNF may have altered in T2DM patients. IL-10 may lessen inflammation-related brain edema and preserve sulcus depth in T2DM patients through its anti-inflammatory activity.

Fermented seeds of Pentaclethra macrophylla mitigate against memory deficit and restored altered enzymatic activity in the brain of streptozotocin-diabetic rats

Memory deficit has been reported as one of the complications of diabetes. Fermented seeds of Pentaclethra Macrophylla (P. macrophylla) have been used in folklore for the management of metabolic diseases. The research aims to evaluate the impact of diets with the inclusion of the fermented seed of P. macrophylla on memory deficit in diabetic rats and its underlying mechanisms. Before the induction, the rats were subjected to training sessions. Thereafter, streptozotocin (50 mg/kg body weight) was administered to the trained rats via intraperitoneal (i.p). 72 hours after, the rats blood glucose level was checked, rats with blood glucose level greater than 250 mg/dl were selected for the memory index evaluation study. The induced rats were randomly distributed into groups: Normal rats (group 1), untreated diabetic rat (Group 2), acarbose treated diabetic rats (group 3); diabetic rats placed on diet supplemented with fermented seed of P. macrophylla (10 & 20% inclusion) were allotted to group 4 & 5. Then, evaluation of memory retention capacity was performed on the day 14 of the experiment. Thereafter, experimental rats were sacrificed, tissue of interest (brain) was excised, homogenized and homogenates were used for biochemical analysis. The cholinergic, angiotensin-1-converting enzyme (ACE), arginase activity and biomarkers for oxidative stress were significantly altered in untreated diabetic rats when compared with non-diabetes rats. Also, the memory capacity of the diabetic rats was significantly reduced when compared with the non-diabetes rats. Meanwhile, diabetic rats placed on diet with fermented seeds of P. macrophylla (10 & 20% inclusion) exhibited significantly higher memory capacity, lower activity of cholinergic, ACE, arginase activity in relation to untreated diabetic rats while the antioxidant status of the brain was enhanced. Nevertheless, fermented seeds of P. macrophylla ameliorated memory deficit in STZ induced diabetes rats. This gave credence to P. macrophylla nutraceutical potential as claimed in folk medicine.

Hotspots and frontier trends of diabetic associated cognitive decline research based on rat and mouse models from 2012 to 2021: A bibliometric study

Background

The establishment of rodent models, such as rat and mouse models, plays a critical role in the study of diabetic associated cognitive decline. With the continuous growth of relevant literature information, it is difficult for researchers to accurately and timely capture the topics in this field. Therefore, this study aims to explore the current status and frontier trends of diabetic associated cognitive decline research based on rat and mouse models through a bibliometric analysis.

Methods

We collected 701 original articles on this subject from the Science Citation Index Expanded of the Web of Science Core Collection from 2012 to 2021. Then we utilized CiteSpace and VOSviewer for plotting knowledge maps and evaluating hotpots and trends.

Results

During this decade, except for a slight decline in 2020, the number of annual outputs on diabetes associated cognitive decline research using rat and mouse models increased every year. China (country), China Pharmaceutical University (institution), Gao, Hongchang (the author from the School of Pharmacy of Wenzhou Medical University, China), and Metabolic Brain Disease (journal) published the most papers in this research field. The analysis results of co-cited references and co-occurrence keywords indicated that "mechanisms and prevention and treatment methods", especially "oxidative stress", "potential association with Alzheimer's disease" and "spatial memory" are research focuses in this subject area. The bursts detection of references and keywords implied that "cognitive impairment of type 1 diabetes" and "autophagy and diabetes associated cognitive decline" will be potential directions for future research in this subject area.

Conclusion

This study systematically assessed general information, current status and emerging trends of diabetic associated cognitive decline research using rat and mouse models in the past decade based on a bibliometric analysis. The number of publications was annually increasing although a slight decline was observed in 2020. Contributions from different countries/regions, institutions, authors, co-cited authors, journals and co-cited journals were evaluated, which may also be used to guide future research. Through the analysis of references and keywords, we predicted the future research hotspots and trends in this field.

New methods for the diagnosis and monitoring of cognitive function in patients with type 2 diabetes

The presence of type 2 diabetes acts as an accelerator of cognitive impairment (mild cognitive impairment and later dementia), with a significant impact on the management of the disease and its complications. Therefore, it is recommended to perform an annual evaluation of cognitive function in patients with diabetes older than 65 years. Current guidelines still recommend the use of the Minimental State Evaluation Test (MMSE) as screening test, but it has a modest sensitivity and specificity for identifying mild cognitive impairment. This represents an important gap because patients with mild cognitive impairment are at risk of progressing to dementia. The neurocognitive diagnosis is based on complex neuropsychological tests, which require specifically trained personnel and are time consuming, making its routine incorporation into daily clinical practice unfeasible. Therefore, at present there are no reliable biomarkers to identify patients with type 2 diabetes at increased risk of developing cognitive impairment. Since the brain and the retina have a common embryological origin, our Research Group, has worked over the last 10 years evaluating the usefulness of the retina as a "window" to the brain. We provided evidence that retinal microperimetry is a simple, feasible and useful tool for screening and monitoring cognitive function in patients with type 2 diabetes. We propose a review of actual tests recommended for screening of cognitive impairment as well as an update of new emerging methods, such as retinal microperimetry.

Efficacy and safety of hypoglycemic drugs in improving cognitive function in patients with Alzheimer's disease and mild cognitive impairment: A systematic review and network meta-analysis

Objective

The purpose of this study was to compare the effects of oral hypoglycaemic drugs (HDs) on cognitive function and biomarkers of mild cognitive impairment (MCI) and Alzheimer's disease (AD) through a network meta-analysis of randomized controlled trials (RCTs).

Methods

We conducted systematic searches for English- and Chinese-language articles in the PubMed, Medline, Embase, Cochrane Library and Google Scholar databases, with no date restrictions. We performed a network meta-analysis, which we report here according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The 16 studies included a total of 3,081 patients. We selected the Mini-Mental State Examination (MMSE), the Alzheimer's Disease Assessment Scale-Cognitive section (ADAS-Cog), the Alzheimer's Disease Cooperative Study Activities of Daily Living section (ADCS-ADL) and amyloid beta (Aβ) 42 as the outcome measures for analysis and comparison.

Result

We selected seven treatments and assessed the clinical trials in which they were tested against a placebo control. Of these treatments, intranasal insulin 20 IU (ITSN20), glucagon-like peptide-1 (GLP-1), and dipeptidyl peptidase 4 inhibitor (DPP-4) were associated with significantly improved MMSE scores (7 RCTs, 333 patients, 30≥MMSE score≥20: mild) compared with placebo [standardized mean difference (SMD) 1.11, 95% confidence interval (CI) (0.87, 1.35); SMD 0.75, 95% CI (0.04, 1.41); and SMD 4.08, 95% CI (3.39, 4.77), respectively]. Rosiglitazone 4 mg (RLZ4), rosiglitazone 10 mg (RLZ10), intranasal insulin 40 IU (ITSN40), and ITSN20 significantly decreased ADAS-Cog scores (11 RCTs, 4044 patients, 10 ≤ ADAS-Cog scores ≤ 30: mild and moderate) compared with placebo [SMD −1.40, 95% CI (−2.57, −0.23), SMD −3.02, 95% CI (−4.17, −1.86), SMD −0.92, 95% CI (−1.77, −0.08), SMD −1.88, 95% CI (−3.09, −0.66)]. Additionally, ITSN20 and ITSN40 significantly improved ADCS-ADL scores (2 RCTs, 208 patients, ADCS-ADL scale score ≤ 10: mild) compared with placebo [SMD 0.02, 95% CI (0.01, 0.03), and SMD 0.04, 95% CI (0.03, 0.05), respectively]. In the 16 included studies, the degree of AD was classified as mild or moderate. For mild cognitive impairment, DPP-4 performed best, but for mild to moderate impairment, ITSN40 had excellent performance.

Conclusion

Various HDs can improve the cognitive function of MCI and AD patients. Different drug regimens brought different degrees of improvement, which may be related to their dosage, duration, and mechanism of action.

Systematic review registration

www.crd.york.ac.uk/prospero.

A deep learning model for detection of Alzheimer's disease based on retinal photographs: a retrospective, multicentre case-control study

BACKGROUND

There is no simple model to screen for Alzheimer's disease, partly because the diagnosis of Alzheimer's disease itself is complex-typically involving expensive and sometimes invasive tests not commonly available outside highly specialised clinical settings. We aimed to develop a deep learning algorithm that could use retinal photographs alone, which is the most common method of non-invasive imaging the retina to detect Alzheimer's disease-dementia.

METHODS

In this retrospective, multicentre case-control study, we trained, validated, and tested a deep learning algorithm to detect Alzheimer's disease-dementia from retinal photographs using retrospectively collected data from 11 studies that recruited patients with Alzheimer's disease-dementia and people without disease from different countries. Our main aim was to develop a bilateral model to detect Alzheimer's disease-dementia from retinal photographs alone. We designed and internally validated the bilateral deep learning model using retinal photographs from six studies. We used the EfficientNet-b2 network as the backbone of the model to extract features from the images. Integrated features from four retinal photographs (optic nerve head-centred and macula-centred fields from both eyes) for each individual were used to develop supervised deep learning models and equip the network with unsupervised domain adaptation technique, to address dataset discrepancy between the different studies. We tested the trained model using five other studies, three of which used PET as a biomarker of significant amyloid β burden (testing the deep learning model between amyloid β positive vs amyloid β negative).

FINDINGS

12 949 retinal photographs from 648 patients with Alzheimer's disease and 3240 people without the disease were used to train, validate, and test the deep learning model. In the internal validation dataset, the deep learning model had 83·6% (SD 2·5) accuracy, 93·2% (SD 2·2) sensitivity, 82·0% (SD 3·1) specificity, and an area under the receiver operating characteristic curve (AUROC) of 0·93 (0·01) for detecting Alzheimer's disease-dementia. In the testing datasets, the bilateral deep learning model had accuracies ranging from 79·6% (SD 15·5) to 92·1% (11·4) and AUROCs ranging from 0·73 (SD 0·24) to 0·91 (0·10). In the datasets with data on PET, the model was able to differentiate between participants who were amyloid β positive and those who were amyloid β negative: accuracies ranged from 80·6 (SD 13·4%) to 89·3 (13·7%) and AUROC ranged from 0·68 (SD 0·24) to 0·86 (0·16). In subgroup analyses, the discriminative performance of the model was improved in patients with eye disease (accuracy 89·6% [SD 12·5%]) versus those without eye disease (71·7% [11·6%]) and patients with diabetes (81·9% [SD 20·3%]) versus those without the disease (72·4% [11·7%]).

INTERPRETATION

A retinal photograph-based deep learning algorithm can detect Alzheimer's disease with good accuracy, showing its potential for screening Alzheimer's disease in a community setting.

FUNDING

BrightFocus Foundation.

The synergistic ameliorative activity of peroxisome proliferator-activated receptor-alpha and gamma agonists, fenofibrate and pioglitazone, on hippocampal neurodegeneration in a rat model of insulin resistance

Insulin resistance (IR) is a risk factor for metabolic disorders and neurodegeneration. Peroxisome proliferator-activated receptor (PPAR) agonists have been proven to mitigate the neuronal pathology associated with IR. However, the synergetic efficacy of these agonists is yet to be fully described. Hence, we aimed to investigate the efficacy of PPARα/γ agonists (fenofibrate and pioglitazone) on a high-fat diet (HFD) and streptozotocin (STZ)-induced hippocampal neurodegeneration. Male Wistar rats (200 ± 25 mg/body weight [BW]) were divided into five groups. The experimental groups were fed on an HFD for 12 weeks coupled with 5 days of an STZ injection (30 mg/kg/BW, i.p) to induce IR. Fenofibrate (FEN; 100 mg/kg/BW, orally), pioglitazone (PIO; 20 mg/kg/BW, orally), and their combination were administered for 2 weeks postinduction. Behavioral tests were conducted, and blood was collected to determine insulin sensitivity after treatment. Animals were killed for assessment of oxidative stress, cellular morphology characterization, and astrocytic evaluation. HFD/STZ-induced IR increased malondialdehyde (MDA) levels and decreased glutathione (GSH) levels. Evidence of cellular alterations and overexpression of astrocytic protein was observed in the hippocampus. By contrast, monotherapy of FEN and PIO increased the GSH level (p < 0.05), decreased the MDA level (p < 0.05), and improved cellular morphology and astrocytic expression. Furthermore, the combined treatment led to improved therapeutic activities compared to monotherapies. In conclusion, FEN and PIO exerted a therapeutic synergistic effect on HFD/STZ-induced IR in the hippocampus.

Body weight variability and the risk of dementia in patients with type 2 diabetes mellitus: A nationwide cohort study in Korea

AIMS

This study aimed to examine the association between body weight variability and dementia risk using a large-scale cohort data of Korean patients with type 2 diabetes mellitus (T2DM).

METHODS

A population-based cohort of 1,206,764 individuals with T2DM aged ≥ 40 years who underwent ≥ 3 Korean national health screenings were followed up until the end of 2019. Body weight variability was assessed using variability independent of the mean (VIM). A multivariate Cox proportional hazard regression was performed with calculating hazard ratios (HRs) with 95 % confidence intervals (CIs) of dementia incidence.

RESULTS

During a median follow-up of 7.9 years, 162,615 (13.4 %) individuals developed dementia. Individuals with greater body weight variability tended to be associated with higher risk of all types of dementia (P for trend < 0.001). Individuals in the highest quartile of VIM showed 26 % (HR: 1.26, 95 % CI: 1.24-1.28), 33 % (HR: 1.33, 95 % CI: 1.30-1.36) and 28 % (HR: 1.28, 95 % CI: 1.23-1.33) higher risk for all-cause dementia, Alzheimer's disease, and vascular dementia, compared with those in the lowest quartile. These associations persisted in all body mass index categories (P for trend < 0.001).

CONCLUSIONS

Maintaining an appropriate body weight may help mitigate dementia risk in patients with T2DM.

Cerebral endothelial cell derived small extracellular vesicles improve cognitive function in aged diabetic rats

Small extracellular vesicles (sEVs) mediate cell-cell communication by transferring their cargo biological materials into recipient cells. Diabetes mellitus (DM) induces cerebral vascular dysfunction and neurogenesis impairment, which are associated with cognitive decline and an increased risk of developing dementia. Whether the sEVs are involved in DM-induced cerebral vascular disease, is unknown. Therefore, we studied sEVs derived from cerebral endothelial cells (CEC-sEVs) of aged DM rats (DM-CEC-sEVs) and found that DM-CEC-sEVs robustly inhibited neural stem cell (NSC) generation of new neuroblasts and damaged cerebral endothelial function. Treatment of aged DM-rats with CEC-sEVs derived from adult healthy normal rats (N-CEC-sEVs) ameliorated cognitive deficits and improved cerebral vascular function and enhanced neurogenesis. Intravenously administered N-CEC-sEVs crossed the blood brain barrier and were internalized by neural stem cells in the neurogenic region, which were associated with augmentation of miR-1 and –146a and reduction of myeloid differentiation primary response gene 88 and thrombospondin 1 proteins. In addition, uptake of N-CEC-sEVs by the recipient cells was mediated by clathrin and caveolin dependent endocytosis signaling pathways. The present study provides ex vivo and in vivo evidence that DM-CEC-sEVs induce cerebral vascular dysfunction and neurogenesis impairment and that N-CEC-sEVs have a therapeutic effect on improvement of cognitive function by ameliorating dysfunction of cerebral vessels and increasing neurogenesis in aged DM rats, respectively.

Sesamin protects against neurotoxicity via inhibition of microglial activation under high glucose circumstances through modulating p38 and JNK signaling pathways

Diabetes mellitus (DM), one of the principal causes of morbidity and mortality worldwide, is implicated in the progression of age-related neurodegenerative diseases (NDDs), in which microglial activation is a crucial mediator. Sesamin, a kind of phytochemical, shows inhibitory effects on microglial activation. The present study studied whether sesamin protects against neurotoxicity triggered by high glucose-induced microglial activation. We firstly demonstrated that high doses of glucose, which mimics hyperglycemia in DM, did induce the activation of murine BV2 microglial cells, increasing inflammatory responses such as the production of ROS or inflammatory mediators like IL-1β, TNF-⍺, and nitric oxide, through activation of p38 and JNK signaling pathways. Next, conditioned medium (CM) collected from high glucose-activated BV2 cell culture was used to show aggravated neurotoxicity in differentiated PC12 cells, indicating that high glucose-activated microglia could induce neurotoxicity. Interestingly, pretreatment of BV2 cells with sesamin diminished high glucose-induced microglia activation and inflammatory responses. Moreover, neurotoxicity in PC12 cells was found to be decreased in the group treated with CM from the sesamin-pretreated BV2 cell culture, suggesting sesamin inhibited microglial activation, thereby protecting neurons from activated microglia-mediated neurotoxicity. Thus, sesamin might be a potential compound to use in the prevention of diabetic-induced NDDs.

Association Between Diabetic Retinopathy, Brain Structural Abnormalities, and Cognitive Impairment for Accumulated Evidence in Observational Studies

PURPOSE

To evaluate the association between diabetic retinopathy (DR) and cerebral disease or cognitive impairment.

DESIGN

Systematic review and meta-analysis.

METHOD

The hypothesis was formulated prior to data collection. Cross-sectional studies and cohort studies that assessed the association between any measure of DR and cerebral small vessel disease or any type of cognitive impairment in diabetic participants were included. The data were independently extracted by two investigators. This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses and Meta-analysis of Observational Studies in Epidemiology guidelines RESULTS: A total of 27 studies were included. The combined odds ratio of 5 cross-sectional/cohort studies that reported that the associations between DR and cerebral structural changes was 1.75 (95% confidence interval [CI]: 1.36-2.25). The combined hazard ratio of 4 cohort studies that examined the association between DR and cognitive impairment events was 1.47 (95% CI: 1.22-1.78). The combined odds ratio of 14 cross-sectional/cohort studies that examined the association between DR and different cognitive impairment events was 1.43 (95% CI: 1.06-1.93). The overall coefficient (β) of 4 studies that examined the relationship between DR and specific cognitive performance was 0.09 (95% CI: 0.00-0.18). Considering the quality of the data, we have performed subgroup analysis in studies scored >7 and studies scored ≤7, respectively, according to the Newcastle-Ottawa scale.

CONCLUSION

The present meta-analysis suggests that DR is associated with an increased risk of structural abnormalities in the brain and cognitive impairment. This association remained significant after adjusting for blood glucose, and the presence of hypertension, indicating that DR is an important danger signal for cerebral abnormalities.

Shen Qi Wan Ameliorates Learning and Memory Impairment Induced by STZ in AD Rats through PI3K/AKT Pathway

Alzheimer’s disease is the most common form of neurodegenerative disease, and increasing evidence shows that insulin signaling has crucial roles in AD initiation and progression. In this study, we explored the effect and underlying mechanism of SQW, a representative formula for tonifying the kidney and promoting yang, on improving the cognitive function in a streptozotocin-induced model of AD rats. We investigated memory impairment in the AD rats by using the Morris water test. HE and Nissl staining were employed to observe the histomorphological changes in the hippocampal. Expression levels of NeuN and proteins related to Tau and apoptosis were measured using immunohistochemistry and Western blotting, respectively. Additionally, we performed RNA sequencing, and the selected hub genes were then validated by qRT-PCR. Furthermore, the protein expression levels of PI3K/AKT pathway-related proteins were detected by Western blot. We found that SQW treatment significantly alleviated learning and memory impairment, pathological damage, and apoptosis in rats, as evidenced by an increased level of NeuN and Bcl-2, and decreased phosphorylation of Tau, Bax, and Caspase-3 protein expression. SQW treatment reversed the expression of insulin resistance-related genes (Nr4a1, Lpar1, Bdnf, Atf2, and Ppp2r2b) and reduced the inhibition of the PI3K/AKT pathway. Our results demonstrate that SQW could contribute to neuroprotection against learning and memory impairment in rats induced by STZ through activation of the PI3K/AKT pathway.

The Ganglion Cell-Inner Plexiform Layer Thickness/Vessel Density of Superficial Vascular Plexus Ratio According to the Progression of Diabetic Retinopathy

Purpose

The purpose of this study was to identify the relationship between the gangion cell-inner plexiform layer (GC-IPL) and retinal vasculature in the context of the progression of diabetic retinopathy (DR).

Methods

The subjects were divided into four groups according to DR stage: normal controls (group 1), patients with diabetes mellitus (DM) without DR (group 2), patients with mild or moderate nonprogressive DR (NPDR; group 3), and patients with severe NPDR (group 4). GC-IPL thickness, vessel density of superficial vascular plexus (SVD), and the GC-IPL/SVD ratio were compared among the groups.

Results

A total of 556 eyes were enrolled; 288 in group 1, 140 in group 2, 76 in group 3, and 52 in group 4. The mean GC-IPL thicknesses were 83.57 ± 7.35, 82.74 ± 7.22, 81.33 ± 6.74, and 79.89 ± 9.16 μm in each group, respectively (P = 0.006). The mean SVDs were 20.40 ± 1.26, 19.70 ± 1.56, 18.86 ± 2.04, and 17.82 ± 2.04 mm⁻¹ in each group, respectively (P < 0.001). The GC-IPL/SVD ratios were 4.11 ± 0.38, 4.22 ± 0.40, 4.36 ± 0.54, and 4.54 ± 0.55 in each group, respectively (P < 0.001). In Pearson's correlation analysis, DR stage was significantly correlated with the GC-IPL/SVD ratio (coefficient = 0.301; P < 0.001).

Conclusions

As the DR stage progressed, the GC-IPL thickness tended to decrease, with the macular SVD showing a significant reduction. Additionally, the impairment of retinal vasculature was more prominent than GC-IPL thinning as DR progressed, which suggests that retinal vasculature changes may precede diabetic retinal neurodegeneration.

Obese Women Have a High Carbohydrate Intake without Changes in the Resting Metabolic Rate in the Luteal Phase

Hormonal changes are caused by the menstrual cycle phases, which influence resting metabolic rate and eating behavior. The aim of the study was to determine resting metabolic rate (RMR) and its association with dietary intake according to the menstrual cycle phase in lean and obese Chilean women. This cross-sectional analytical study included 30 adult women (15 lean and 15 with obesity). Body composition was measured with a tetrapolar bioelectrical impedance meter. Nutritional status was determined by adiposity. A 24-h recall of three nonconsecutive days verifies dietary intake. The RMR was measured by indirect calorimetry. All measurements were performed in both the follicular and luteal phases of the menstrual cycle. Statistical analyses were performed with STATA software at a significance level, which was α = 0.05. The RMR (β = 121.6 kcal/d), temperature (β = 0.36 °C), calorie intake (β = 317.1 kcal/d), and intake of lipids (β = 13.8 g/d) were associated with the luteal phase in lean women. Only extracellular water (β = 1.11%) and carbohydrate consumption (β = 45.2 g/d) were associated in women with obesity. Lean women showed increased RMR, caloric intake, and lipid intake during the luteal phase. For women with obesity, carbohydrate intake increased but not RMR.

High-fat diet exacerbates cognitive and metabolic abnormalities in neuronal BACE1 knock-in mice - partial prevention by Fenretinide

Objective: The β-site APP-cleaving enzyme 1 (BACE1) is a rate-limiting step in β-amyloid (Aβ) production in Alzheimer's disease (AD) brains, but recent evidence suggests that BACE1 is also involved in metabolic regulation. Here, we aimed to assess the effects of highfat diet (HFD) on metabolic and cognitive phenotypes in the diabetic BACE1 knock-in mice (PLB4) and WT controls; we additionally examined whether these phenotypes can be normalized with a synthetic retinoid (Fenretinide, Fen) targeting weight loss.Methods: Five-month old male WT and PLB4 mice were fed either (1) control chow diet, (2) 45%-saturated fat diet (HFD), (3) HFD with 0.04% Fen (HFD + Fen) or (4) control chow diet with 0.04% Fen (Fen) for 10 weeks. We assessed basic metabolic parameters, circadian rhythmicity, spatial habituation (Phenotyper) and working memory (Y-maze). Hypothalami, forebrain and liver tissues were assessed using Western blots, qPCR and ELISAs.Results: HFD feeding drastically worsened metabolism and induced early mortality (-40%) in otherwise viable PLB4 mice. This was ameliorated by Fen, despite no effects on glucose intolerance. In HFD-fed WT mice, Fen reduced weight gain, glucose intolerance and hepatic steatosis. The physiological changes induced in WT and PLB4 mice by HFD (+/-Fen) were accompanied by enhanced cerebral astrogliosis, elevated PTP1B, phopsho-eIF2α and altered hypothalamic transcription of Bace1, Pomc and Mc4r. Behaviourally, HFD feeding exacerbated spatial memory deficits in PLB4 mice, which was prevented by Fen and linked with increased full-length APP, normalized brain Aβ*56 oligomerization and astrogliosis.Conclusions: HFD induces early mortality and worsened cognition in the Alzheimer's-like BACE1 mice- partial prevention was achieved with Fenretinide, without improvements in glucose homeostasis.

Comparative efficacy and safety of traditional Chinese patent medicine for cognitive dysfunction in diabetic cognitive dysfunction: A protocol for systematic review and Bayesian network meta-analysis

BACKGROUND

More and more studies have shown that cognitive dysfunction is one of the main complications of diabetes. The disorder of glucose and lipid metabolism seriously damages brain function and accelerates the conversion to dementia. At present, there are no drugs that can directly treat diabetic cognitive dysfunction. All drugs for the treatment of this disease achieve the purpose of treatment through strict control of blood sugar levels. This method has great limitations. Traditional Chinese patent medicines (TCPMs) work through multiple targets and multiple pathways, which can not only effectively correct the state of glucose and lipid metabolism disorders, but also significantly improve cognitive ability, but there is a lack of systematic evaluation of their effectiveness and safety. We use the method of network meta-analysis to systematically and comprehensively compare the effectiveness and safety of different Chinese patent medicines.

METHODS

We will comprehensively search the following databases, including Web of Science, PubMed, The Cochrane Library, EMBASE, China National Knowledge Infrastructure, Chinese Scientific Journals Database, Wanfang database and China BioMedical Literature. We will include all randomized controlled trials that meet the inclusion criteria, starting from the establishment of the database until September 2021. Two researchers will independently screen the literature based on inclusion criteria. While extracting data, we also assess the risk of bias in the included studies. All the data and evidence obtained will be evaluated by the method of Bayesian network meta-analysis.

RESULTS

This study will evaluate the effectiveness and safety of various TCPMs for diabetic cognitive dysfunction.

CONCLUSION

The results of this study will provide valuable references for the clinical application of TCPMs, and assist clinicians in formulating more reasonable diagnosis and treatment strategies.

ETHICS AND DISSEMINATION

This study does not require ethical approval.

INTERNATIONAL PLATFORM OF REGISTERED SYSTEMATIC REVIEW AND METAANALYSIS PROTOCOLS REGISTRATION NUMBER

INPLASY202190008.

Shared Molecular Mechanisms among Alzheimer’s Disease, Neurovascular Unit Dysfunction and Vascular Risk Factors: A Narrative Review

Alzheimer’s disease (AD) is the most common type of dementia, affecting 24 million individuals. Clinical and epidemiological studies have found several links between vascular risk factors (VRF), neurovascular unit dysfunction (NVUd), blood-brain barrier breakdown (BBBb) and AD onset and progression in adulthood, suggesting a pathogenetic continuum between AD and vascular dementia. Shared pathways between AD, VRF, and NVUd/BBB have also been found at the molecular level, underlining the strength of this association. The present paper reviewed the literature describing commonly shared molecular pathways between adult-onset AD, VRF, and NVUd/BBBb. Current evidence suggests that VRF and NVUd/BBBb are involved in AD neurovascular and neurodegenerative pathology and share several molecular pathways. This is strongly supportive of the hypothesis that the presence of VRF can at least facilitate AD onset and progression through several mechanisms, including NVUd/BBBb. Moreover, vascular disease and several comorbidities may have a cumulative effect on VRF and worsen the clinical manifestations of AD. Early detection and correction of VRF and vascular disease by improving NVUd/BBBd could be a potential target to reduce the overall incidence and delay cognitive impairment in AD.

The Value of Optical Coherence Tomography Angiography (OCT-A) in Neurological Diseases

Optical coherence tomography angiography (OCT-A) was commercially introduced in 2014. OCT-A allows a fast, non-invasive, three-dimensional analysis of the retinal vasculature from the vitreoretinal interface to the choriocapillaris. The results can be evaluated separately in automated or custom-defined retinal layers. Since its introduction, OCT-A has also been used in patients with neurological diseases in order to find and characterize retinal biomarkers. Many neurological diseases have retinal manifestations, often preceding the key symptoms of the neurological disease. Anatomically and developmentally, the retina is a part of the brain. In contrast to the brain, the retina is easily accessible for imaging methods; moreover, retinal imaging is more cost-effective than brain imaging. In this review, the current knowledge about OCT-A findings and possible OCT-A biomarkers in neurological diseases is summarized and discussed regarding the value of OCT-A as a diagnostic tool in neurological diseases.

Diabetic Retinopathy Predicts Risk of Alzheimer’s Disease: A Danish Registry-Based Nationwide Cohort Study

Background:

Retinal neurodegeneration is evident in early diabetic retinopathy (DR) which may be associated with other neurodegenerative diseases like Alzheimer's disease (AD).

Objective:

To investigate diabetes and DR as a risk marker of present and incident AD.

Methods:

A register-based cohort study was performed. We included 134,327 persons with diabetes above 60 years of age, who had attended DR screening, and 651,936 age- and gender-matched persons without diabetes.

Results:

At baseline, the prevalence of AD was 0.7% and 1.3% among patients with and without diabetes, respectively. In a multivariable regression model, patients with diabetes were less likely to have AD at baseline (adjusted OR 0.63, 95% CI 0.59–0.68). During follow-up, incident AD was registered for 1473 (0.35%) and 6,899 (0.34%) persons with and without diabetes, respectively. Compared to persons without diabetes, persons with diabetes and no DR had a lower risk to develop AD (adjusted HR 0.87, 95% CI 0.81–0.93), while persons with diabetes and DR had higher risk of AD (adjusted HR 1.24, 95% CI 1.08–1.43). When persons with diabetes and no DR were used as references, a higher risk of incident AD was observed in persons with DR (adjusted HR 1.34, 95% CI 1.18–1.53).

Conclusion:

Individuals with diabetes without DR were less likely to develop AD compared to persons without diabetes. However, individuals with DR had a 34% higher risk of incident AD, which raise the question whether screening for cognitive impairment should be done among individuals with DR.

Altered dynamic functional architecture in type 2 diabetes mellitus

INTRODUCTION

Type 2 diabetes mellitus (T2DM) can accelerate cognitive decline and even dementia so that the underlying mechanism deserves further exploration. In the resting state, brain function is still changing dynamically. At present, it is still unknown whether the dynamic functional connectivity (dFC) between various brain regions is in a stable state. It is necessary to interpret brain changes from a new perspective, that is, the stability of brain architecture.

METHODS

In this study, we used a fixed dynamic time scale to explore the stability of dynamic functional architecture in T2DM, then the dynamic effective connectivity (dEC) was used to further explain how information flows through dynamically fluctuating brain architecture in T2DM.

RESULT

Two brain regions with decreased stability were found including the right supra-marginal gyrus (SMG) and the right median cingulate gyrus (MCG) in T2DM subjects. The dEC variation has increased between the left inferior frontal gyrus (IFG) and the right MCG. The direction of causal flow is from the right MCG to the left IFG.

CONCLUSION

The combination of stability and dEC can not only show the stability of dynamic functional architecture in brain but also reflect the fluidity of brain information, which is an innovative and interesting attempt in the field of neuroimaging. The changes of dynamic architecture in T2DM patients may present an innovative perspective and explanation for their cognitive decline.

Expression of Ferroptosis-Related Genes is Correlated with Immune Microenvironment in Diabetic Kidney Disease

OBJECTIVE

This study aims to explore the correlation between ferroptosis and immune microenvironment (IME) in diabetic kidney disease (DKD) to provide a new clue for exploring the underlying molecular mechanisms.

METHODS

Corresponding RNA data of DKD patients were downloaded from GEO databases. The weighted gene co-expression network analysis (WGCNA) was used to construct the network, and the selected hub genes, then, overlapped with ferroptosis-related genes (FRGs) from FerrDb. Consensus clustering was performed to identify new molecular subgroups. ESTIMATE, TIMER and ssGSEA analyses were applied to determinate the IME and immune status. Functional analyses including GO, KEGG and GSEA were conducted to elucidate the underlying mechanisms.

RESULTS

Two molecular subtypes were identified based on the expression of FRGs. ESTIMATE algorithm revealed that there were significant differences in ESTIMATE score between these two clusters of DKD patients, with no significant difference found in stromal score and immune score. In addition, TIMER algorithm indicated there was a significant difference in the degree of T cell infiltration. The ssGSEA algorithm showed immunity was mainly concentrated in thick ascending limb and distal convoluted tubule in adult kidney. GO, KEGG and GSEA analyses revealed that the differentially expressed genes (DEGs) were mainly enriched in immune and metabolism associated pathways.

CONCLUSION

The ferroptosis may be induced by dysregulation of IME, thereby accelerating the progression of DKD. Our work could be applied to provide a new clue for exploring the underlying molecular mechanisms and sheds novel light on the therapy strategy of DKD.

Artificial intelligence promotes the diagnosis and screening of diabetic retinopathy

Deep learning evolves into a new form of machine learning technology that is classified under artificial intelligence (AI), which has substantial potential for large-scale healthcare screening and may allow the determination of the most appropriate specific treatment for individual patients. Recent developments in diagnostic technologies facilitated studies on retinal conditions and ocular disease in metabolism and endocrinology. Globally, diabetic retinopathy (DR) is regarded as a major cause of vision loss. Deep learning systems are effective and accurate in the detection of DR from digital fundus photographs or optical coherence tomography. Thus, using AI techniques, systems with high accuracy and efficiency can be developed for diagnosing and screening DR at an early stage and without the resources that are only accessible in special clinics. Deep learning enables early diagnosis with high specificity and sensitivity, which makes decisions based on minimally handcrafted features paving the way for personalized DR progression real-time monitoring and in-time ophthalmic or endocrine therapies. This review will discuss cutting-edge AI algorithms, the automated detecting systems of DR stage grading and feature segmentation, the prediction of DR outcomes and therapeutics, and the ophthalmic indications of other systemic diseases revealed by AI.

Common pathways in dementia and diabetic retinopathy: understanding the mechanisms of diabetes-related cognitive decline

Type 2 diabetes (T2D) is associated with multiple comorbidities, including diabetic retinopathy (DR) and cognitive decline, and T2D patients have a significantly higher risk of developing Alzheimer's disease (AD). Both DR and AD are characterized by a number of pathological mechanisms that coalesce around the neurovascular unit, including neuroinflammation and degeneration, vascular degeneration, and glial activation. Chronic hyperglycemia and insulin resistance also play a significant role, leading to activation of pathological mechanisms such as increased oxidative stress and the accumulation of advanced glycation end-products (AGEs). Understanding these common pathways and the degree to which they occur simultaneously in the brain and retina during diabetes will provide avenues to identify T2D patients at risk of cognitive decline.

Diabetes/Dementia in Sub-saharian Africa and Nigerian Women in the Eye of Storm

In the next few years, the prevalence of diabetes mellitus (DM) is projected to dramatically increase globally, but most of the cases will occur in low-to-middle-income countries. Some of the major risk factors for diabetes accelerate the development of dementia in African-Americans, thus leading to a higher prevalence of dementia than Caucasians. Sub-Saharan Africa women have a disproportionately two-to-eight fold increased prevalence of dementia. In the eye of this storm, Nigeria holds the highest number of diabetics on the African continent, and its prevalence is rising in parallel to obesity, hypertension, and the population's aging. The socio-economic impact of the rising prevalence of DM and dementia will be huge and unsustainable for the healthcare system in Nigeria, as has been recognized in developed economies. Here, we analyze the current situation of women's health in Nigeria and explore future perspectives and directions. The complex interplay of factors involved in diabetes and dementia in Nigerian women include key biological agents (metabolic syndrome, vascular damage, inflammation, oxidative stress, insulin resistance), nutritional habits, lifestyle, and anemia, that worsen with comorbidities. In addition, restricted resources, lack of visibility, and poor management result in a painful chain that increases the risk and burden of disease in Nigerian women from youth to elderly ages. Heath policies to increase the ra- tio of mental health professionals per number of patients, mostly in rural areas, foment of proactive primary care centers, and interventions targeting adolescents and adult women and other specific mothers-children pairs are strongly required for a sustainable development goal.

Segmentation of Prefrontal Lobe Based on Improved Clustering Algorithm in Patients with Diabetes

Diabetics are prone to postoperative cognitive dysfunction (POCD). The occurrence may be related to the damage of the prefrontal lobe. In this study, the prefrontal lobe was segmented based on an improved clustering algorithm in patients with diabetes, in order to evaluate the relationship between prefrontal lobe volume and COPD. In this study, a total of 48 diabetics who underwent selective noncardiac surgery were selected. Preoperative magnetic resonance imaging (MRI) images of the patients were segmented based on the improved clustering algorithm, and their prefrontal volume was measured. The correlation between the volume of the prefrontal lobe and Z-score or blood glucose was analyzed. Qualitative analysis shows that the gray matter, white matter, and cerebrospinal fluid based on the improved clustering algorithm were easy to distinguish. Quantitative evaluation results show that the proposed segmentation algorithm can obtain the optimal Jaccard coefficient and the least average segmentation time. There was a negative correlation between the volume of the prefrontal lobe and the Z-score. The cut-off value of prefrontal lobe volume for predicting POCD was <179.8, with the high specificity. There was a negative correlation between blood glucose and volume of the prefrontal lobe. From the results, we concluded that the segmentation of the prefrontal lobe based on an improved clustering algorithm before operation may predict the occurrence of POCD in diabetics.

Metabolic syndrome and the risk of late onset Alzheimer's disease: An updated review and meta-analysis

AIMS

This study aims to provide an updated systematic review and meta-analysis on the risk of Alzheimer's disease (AD) in patients with metabolic syndrome (MetS) and to analyze the contribution of each MetS component on AD onset.

DATA SYNTHESIS

The study was performed according to the PRISMA guideline. Data were obtained searching MEDLINE, Scopus, Web of Science, and EMBASE for studies published between January 1, 2010 and July 30, 2020, evaluating the association between MetS and AD risk. A total of 255 articles were retrieved and 6 investigations (4 prospective and 2 retrospective) met the inclusion criteria. Overall, 9.788.021 patients with a mean follow-up of 4.5 years were analyzed. The pooled analysis revealed a slight increased risk of AD in MetS (hazard ratio, HR: 1.10, 95% and confidence interval, CI: 1.05-1.15). Egger's test indicated the absence of publication bias (t = 2.095 and p = 0.104). However, while analysis based on prospective studies failed to show a significant association between MetS and AD (HR: 0.80 and 95% CI: 0.61-1.05), analysis based on retrospective studies demonstrated a significant, slight increased risk (HR:1.11 and 95% CI: 1.08-1.66). With regard to MetS components, the risk was: arterial hypertension, HR: 1.05 (95% CI: 1.04-10.6); hyperglycemia/diabetes, HR: 1.19 (95% CI: 1.18-1.99); low high-density lipoprotein cholesterol (HDL-C), HR: 1.07 (95% CI: 1.06-1.07); hypertriglyceridemia, HR: 1.06 (95% CI: 1.05-1.06); and abdominal obesity, HR: 0.84 (95% CI: 0.74-0.95).

CONCLUSIONS

We found a significant association between MetS and AD, mainly driven by large retrospective studies. Our data also support the association of single MetS components with AD incidence, while increased waist circumference seems to have a "protective role" probably due to reverse causality.

Effects of Berberine on Diabetes and Cognitive Impairment in an Animal Model: The Mechanisms of Action

Diabetes is a group of metabolic disorders with an increased risk of developing cognitive impairment and dementia. The hippocampus in the forebrain contains an abundance of insulin receptors related to cognitive function and plays an important role in the pathophysiology of neurodegenerative disorders. Berberine from traditional Chinese medicine has been used to treat diabetes and diabetic cognitive impairment, although its related mechanisms are largely unknown. In this study, a STZ diabetes rat model feeding with a high-fat diet was used to test the effects of berberine compared with metformin. Oral glucose tolerance and hyperinsulinemic-euglycemic clamp were used for glucose metabolism and insulin resistance. The Morris water maze was used to observe the compound effects on cognitive impairment. Serum and hippocampal [Formula: see text]-amyloid peptide (A[Formula: see text], Tau and phosphorylated Tau protein deposition in the hippocampi were measured. The TUNEL assay was used to detect the neuronal apoptosis, supported by histomorphological changes and transmissional electron microscopy (TEM) image. Our data showed that the diabetic rats had a significantly cognitive impairment. In addition to improving glucose metabolism and reducing insulin resistance, berberine significantly improved the cognitive function in the rat. Berberine also effectively decreased the expression of hippocampal tau protein, phosphorylated Tau, and increased insulin receptor antibodies. Moreover, berberine downregulated the abnormal phosphorylation of A[Formula: see text] and Tau protein and improved hippocampal insulin signaling. The TUNEL assay confirmed that berberine reduced hippocampal neuronal apoptosis supported by TEM. Thus, berberine significantly improved the cognitive function in diabetic rats by changing the peripheral and central insulin resistance. The reduction of neuronal injury, A[Formula: see text] deposition, abnormal phosphorylation of Tau protein, and neuronal apoptosis in the hippocampus were observed as the related mechanisms of action.

Alzheimer’s disease and type 2 diabetes mellitus: Pathophysiologic and pharmacotherapeutics links

At present, Alzheimer’s disease (AD) and type 2 diabetes mellitus (T2DM) are two highly prevalent disorders worldwide, especially among elderly individuals. T2DM appears to be associated with cognitive dysfunction, with a higher risk of developing neurocognitive disorders, including AD. These diseases have been observed to share various pathophysiological mechanisms, including alterations in insulin signaling, defects in glucose transporters (GLUTs), and mitochondrial dysfunctions in the brain. Therefore, the aim of this review is to summarize the current knowledge regarding the molecular mechanisms implicated in the association of these pathologies as well as recent therapeutic alternatives. In this context, the hyperphosphorylation of tau and the formation of neurofibrillary tangles have been associated with the dysfunction of the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways in the nervous tissues as well as the decrease in the expression of GLUT-1 and GLUT-3 in the different areas of the brain, increase in reactive oxygen species, and production of mitochondrial alterations that occur in T2DM. These findings have contributed to the implementation of overlapping pharmacological interventions based on the use of insulin and antidiabetic drugs, or, more recently, azeliragon, amylin, among others, which have shown possible beneficial effects in diabetic patients diagnosed with AD.

Potential Overtreatment and Undertreatment of Type 2 Diabetes Mellitus in Long-Term Care Facilities: A Systematic Review

OBJECTIVE

To investigate the prevalence, outcomes, and factors associated with potential glycemic overtreatment and undertreatment of type 2 diabetes mellitus (T2DM) in long-term care facilities (LTCFs).

DESIGN

Systematic review.

SETTING AND PARTICIPANTS

Residents with T2DM and aged ≥60 years living in LTCFs.

MEASURES

Articles published between January 2000 and September 2020 were retrieved following a systematic search of MEDLINE, EMBASE, Cochrane Library, CINAHL plus, and gray literature. Inclusion criteria were the reporting of (1) potential overtreatment and undertreatment quantitatively defined (implicitly or explicitly) based on hemoglobin A1c (HbA1c) and/or blood glucose; (2) prevalence, outcomes, and associated factors of potential glycemic overtreatment and undertreatment; and (3) the study involved residents of LTCFs.

RESULTS

Fifteen studies were included. Prevalence of potential overtreatment (5%-86%, n = 15 studies) and undertreatment (1.4%-35%, n = 8 studies) varied widely among facilities and geographical locations, and according to definitions used. Prevalence of potential overtreatment was 16%-74% when defined as treatment with a glucose-lowering medication in a resident with ≥1 hypoglycemia risk factor or serious comorbidity, together with a HbA1c <7% (n = 10 studies). Potential undertreatment was commonly defined as residents on glucose-lowering medication having HbA1c >8.5% and the prevalence 1.4%-14.8% (n = 6 studies). No studies prospectively measured resident health outcomes from overtreatment and undertreatment. Potential overtreatment was positively associated with use of oral glucose-lowering medications, dementia diagnosis or dementia severity, and/or need for assistance with activities of daily living (n = 2 studies). Negative association was found between potential overtreatment and use of insulin/combined insulin and oral glucose-lowering medication. No studies reported factors associated with potential undertreatment.

CONCLUSIONS AND IMPLICATIONS

The prevalence of potential glycemic overtreatment and undertreatment varied widely among residents with T2DM depending on the definition(s) used in each study. Longitudinal studies examining associations between glycemic management and health outcomes, and the use of consensus definitions of overtreatment and undertreatment are required to establish findings about actual glycemic overtreatment and undertreatment in LTCFs.