Impact of diabetes on cognitive function and brain structure

Effects of obesity on aging brain and cognitive decline: A cohort study from the UK Biobank

Objective

To investigate the impact of obesity on brain structure and cognition using large neuroimaging and genetic data.

Methods

Associations between body mass index (BMI), gray matter volume (GMV), whiter matter hyper-intensities (WMH), and fluid intelligence score (FIS) were estimated in 30283 participants from the UK Biobank. Longitudinal data analysis was conducted. Genome-wide association studies were applied to explore the genetic loci associations among BMI, GMV, WMH, and FIS. Mendelian Randomization analyses were applied to further estimate the effects of obesity on changes in the brain and cognition.

Results

The observational analysis revealed that BMI was negatively associated with GMV (r = -0.15, p < 1 × 10-24) and positively associated with WMH (r = 0.08, p < 1 × 10-16). The change in BMI was negatively associated with the change in GMV (r = -0.04, p < 5 × 10-5). Genetic overlap was observed among BMI, GMV, and FIS at SBK1 (rs2726032), SGF29 (rs17707300), TUFM (rs3088215), AKAP6 (rs1051695), IL27 (rs4788084), and SPI1 (rs3740689 and rs935914). The MR analysis provided evidence that higher BMI was associated with lower GMV (β=-1119.12, p = 5.77 ×10-6), higher WMH (β=42.76, p = 6.37 ×10-4), and lower FIS (β=-0.081, p = 1.92 ×10-23).

Conclusions

The phenotypic and genetic association between obesity and aging brain and cognitive decline suggested that weight control could be a promising strategy for slowing the aging brain.

Investigating metabolic characteristics of type 2 diabetes mellitus-related cognitive dysfunction and correlating therapeutic effects of Di Dang Tang in animal models

ETHNOPHARMACOLOGICAL RELEVANCE

Di Dang Tang is a classic formula from Shang Han Lun, originally used to treat conditions such as blood stasis and heat accumulation. It is widely applied in the treatment of diabetes and its complications, but its effects on Type 2 Diabetes Mellitus-related Cognitive Dysfunction (T2DM-CD) remain unclear.

AIM OF THE STUDY

The study aimed to investigate the metabolic characteristics of patients with T2DM-CD. Additionally, it sought to evaluate the effects of Di Dang Tang on cognitive function in T2DM-CD model rats by targeting the metabolic pathways identified in the clinical analysis, exploring the underlying mechanisms through animal experiments.

METHODS

Fasting venous serum was collected from patients with Type 2 Diabetes Mellitus (T2DM) to detect metabolism-related products, and KEGG annotation analysis was performed. Separately, thirty rats were randomly divided using a random number table method, with six rats selected as the blank control group. Twenty-four successfully modeled rats were then randomly divided into the model group and three Di Dang Tang groups (low, medium, and high doses). After administering the medication, the relevant indicators in the rats were assessed.

RESULTS

Clinical metabolomics detected 32 key differential metabolites between the T2DM-CD and the blank control groups. Between the T2DM-CD and T2DM groups, 29 key differential metabolites were identified. In animal experiments, blood glucose levels in the model group were significantly higher compared to the blank control group at the same time points, whereas the high dose groups of Di Dang Tang exhibited reduced blood glucose levels at weeks 6 and 8 relative to the model group. In the Morris water maze test, the model group had longer escape latencies than the blank control group. The medium and high dose groups of Di Dang Tang showed shorter latencies. Additionally, compared to the model group, the Di Dang Tang groups spent more time and covered more distance in the target quadrant but had reduced average proximity and fewer platform entries. HE staining observation of the hippocampal CA1 area showed no apparent pathological changes in the blank group, obvious pathological damage in the model group, and no significant pathological changes in the medium and high dose groups of Di Dang Tang. Compared to the blank control group, the model group showed significant increases in the levels of Arachidonic Acid (AA), Ceramide (Cer), Glutamate (Glu), TNF- α, IL-1β, TG, and LDL-C, and a significant decrease in HDL-C levels. Compared to the model group, the groups of Di Dang Tang significantly modulated the levels of the above indicators. In Western Blot (WB) assays, compared to the blank control group, the model group rats exhibited significantly higher levels of cPLA2, PKC, ERK, and JNK , and significantly lower levels of claudin-5, NMDA, CaMKII, CREB, and BDNF. The Di Dang Tang groups significantly altered the levels of the above indicators compared to the model group.

CONCLUSION

Amino acid metabolism, sphingolipid signaling pathways, glycerophospholipid metabolism, and various signaling pathways play significant roles in the pathogenesis of T2DM-CD. Di Dang Tang can improve learning and memory abilities in T2DM model rats and ameliorate cognitive impairments, potentially by regulating metabolic levels and inflammatory responses.

Unravelling pathological ageing with brain age gap estimation in Alzheimer's disease, diabetes and schizophrenia

Brain age gap estimation (BrainAGE), the difference between predicted brain age and chronological age, might be a putative biomarker aiming to detect the transition from healthy to pathological brain ageing. The biomarker primarily models healthy ageing with machine learning models trained with structural magnetic resonance imaging (MRI) data. BrainAGE is expected to translate the deviations in neural ageing trajectory and has been shown to be increased in multiple pathologies, such as Alzheimer's disease (AD), schizophrenia and Type 2 diabetes (T2D). Thus, accelerated ageing seems to be a general feature of neuropathological processes. However, neurobiological constraints remain to be identified to provide specificity to this biomarker. Explainability might be the key to uncovering age predictions and understanding which brain regions lead to an elevated predicted age on a given pathology compared to healthy controls. This is highly relevant to understanding the similarities and differences in neurodegeneration in AD and T2D, which remains an outstanding biological question. Sensitivity maps explain models by computing the importance of each voxel on the final prediction, thereby contributing to the interpretability of deep learning approaches. This paper assesses whether sensitivity maps yield different results across three conditions related to pathological neural ageing: AD, schizophrenia and T2D. Five deep learning models were considered, each model trained with different MRI data types: minimally processed T1-weighted brain scans, and corresponding grey matter, white matter, cerebrospinal fluid tissue segmentation and deformation fields (after spatial normalization). Our results revealed an increased BrainAGE in all pathologies, with a different mean, which is the smallest in schizophrenia; this is in line with the observation that neural loss is secondary in this early-onset condition. Importantly, our findings suggest that the sensitivity, indexing regional weights, for all models varies with age. A set of regions were shown to yield statistical differences across conditions. These sensitivity results suggest that mechanisms of neurodegeneration are quite distinct in AD and T2D. For further validation, the sensitivity and the morphometric maps were compared. The findings outlined a high congruence between the sensitivity and morphometry maps for age and clinical group conditions. Our evidence outlines that the biological explanation of model predictions is vital in adding specificity to the BrainAGE and understanding the pathophysiology of chronic conditions affecting the brain.

Early peripheral nerve impairments in type 1 diabetes are associated with cortical inhibition of ankle joint proprioceptive afference

OBJECTIVE

Diabetic sensorimotor peripheral neuropathy (DSPN) is a common complication of type 1 diabetes mellitus (T1DM). However, it is still unclear how the cortical processing of proprioceptive afference is altered due to DSPN.

METHODS

Cortical responses to right and left ankle joint rotations were recorded with magnetoencephalography and pooled together in 20 T1DM participants and 20 healthy controls for source space comparisons. T1DM participants also underwent a lower limb nerve-conduction study to correlate peripheral nerve function with the cortical responses.

RESULTS

Primary sensorimotor (SM1) cortex activation was wider in T1DM patients during beta suppression, with no between-group differences in the response strength. However, stronger beta suppressions in T1DM patients were correlated with axon-loss in the peripheral sensory afferents (p < 0.05). Weaker beta rebounds and stronger SM1 evoked field amplitudes were associated with impaired conduction velocities in the mixed nerves (p < 0.05). Lastly, stronger SM1 beta power was associated with both demyelination and axon-loss in the lower limb sensory afferents (p < 0.05).

CONCLUSIONS

T1DM is accompanied with wider SM1 cortex activation to proprioceptive stimuli, and the early asymptomatic DSPN impairments are linked to increased levels of cortical inhibition.

SIGNIFICANCE

T1DM is associated with comprehensive central pathophysiology evident in early DSPN.

Clinical Profile of Acute Kidney Injury in Type 2 Diabetes Mellitus Adult Patients Presenting With Diabetic Ketoacidosis: A Cross-Sectional Study

OBJECTIVE

 The purpose of this cross-sectional study was to identify the characteristics of acute kidney injury (AKI) in adult patients with type 2 diabetes mellitus (T2DM) who were admitted with diabetic ketoacidosis (DKA).

METHODOLOGY

 One hundred patients were selected based on the inclusion and exclusion criteria. Kidney function was assessed using kidney estimated glomerular filtration rate (KeGFR) calculations based on the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Data collection included clinical, biological, and demographic information. Univariate and multivariate logistic regression analyses were performed, with a p-value of less than 0.05 considered statistically significant. The study also examined risk factors, intensive care unit (ICU) treatments, and clinical outcomes.

RESULTS

AKI was significantly associated with ICU length of stay (p = 0.002), and all patients with prolonged ICU admission developed this condition. A higher incidence of AKI was observed in patients requiring mechanical ventilation, renal replacement therapy, or inotropic support. Among the 100 patients included in the study, 94 achieved clinical recovery, including 76 who had AKI, while six patients did not survive.

CONCLUSION

AKI is a common complication of DKA in adults with T2DM, particularly in hot climate regions. Most cases were detected within the first 24 hours, classified as stage 1 severity, and were pre-renal. Early detection plays a crucial role in preventing complications and improving patient recovery. KeGFR calculations proved an effective tool for monitoring kidney function changes in these patients.

Cognitive Function Deficits Associated With Type 2 Diabetes and Retinopathy: Volumetric Brain MR Imaging Study

INTRODUCTION

Type 2 diabetes mellitus is a ubiquitous chronic inflammatory disease with deleterious effects on various tissues, including the kidney, retina, and peripheral nerves. Studies using histopathology and magnetic resonance imaging have revealed that diabetes-related chronic hyperglycemia may impact the brain's essential functioning by causing microvascular damage. The aim of this study was to examine the cognitive functioning of type 2 diabetic individuals with and without retinopathy by evaluating their morphological, structural, and biochemical differences.

METHODS

Demographic characteristics, education level, type of diabetes mellitus (DM), disease duration, treatment received, other diabetic complications, such as nephropathy and neuropathy, and detailed medical histories were recorded. All participants underwent an extensive neuropsychological examination with Montreal Cognitive Assessment (MoCA) testing. Brain magnetic resonance imaging was performed to evaluate gray matter volume differences between the groups.

RESULTS

Gray matter volume differences between the groups were observed. Differences were observed after multiple corrections (age, education, and total intracranial volume [TIV]). First, the diabetic retinopathy group exhibited a significantly smaller gray matter volume in the right inferior temporal gyrus than the diabetic group (p = 0.032). In addition, the diabetic retinopathy group exhibited a significantly smaller gray matter volume than the control group in the right insula (lateral and central part) (p = 0.011). In addition, MoCA scores exhibited significant correlation with the two regions emerging as statistically significant in our analyses (the right inferior temporal gyrus and right insula) (p = 0.003, p = 0.002, respectively).

CONCLUSION

Our results suggest the presence of a neurodegenerative process associated with cognitive dysfunction that is particularly prominent in the retinopathy stage of DM.

Three-protein signature is associated with baseline and persistently elevated or recurrent depressive symptoms in individuals with recent-onset diabetes

Depression is associated with diabetes, but the underlying causes remain unclear. To better understand depression in diabetes, this study investigated associations between 135 inflammatory and neurological protein biomarkers and depressive symptoms in individuals with diabetes.This cross-sectional study included 430 adults with a known diabetes duration <1 year from the German Diabetes Study (GDS), in whom biomarkers were measured in serum and depressive symptoms were evaluated at baseline and annually over 5 years using the Center for Epidemiological Studies Depression Scale (CES-D). Based on the information on depressive symptoms from the baseline and follow-up visits (n=305, ≥3 time points), we subdivided the sample into individuals with persistent or recurrent and transient or never depressive symptoms. We assessed the associations of each biomarker with baseline CES-D score (continuous) and persistent/recurrent depressive symptoms using multiple linear and logistic regression models, respectively.After adjustment for covariates, we identified a three-protein signature associated with baseline CES-D score and persistent/recurrent depressive symptoms. CUB domain-containing protein 1 (CDCP1) and NAD-dependent protein deacetylase sirtuin-2 (SIRT2) were positively associated with baseline (β 1.24 (95% CI 0.19 to 2.29); β 0.89 (95% CI 0.06 to 1.72)), respectively) and persistent/recurrent depressive symptoms (OR 1.58 (95% CI 1.08 to 2.31); OR 1.32 (95% CI 1.03 to 1.71), respectively), whereas leptin receptor (LEPR) was inversely associated with baseline (β -0.99 (95% CI -1.87 to -0.11)) and persistent/recurrent depressive symptoms (OR 0.70 (95% CI 0.49 to 0.99)). However, results were not significant after adjustment for multiple testing.In conclusion, the three-protein signature identified may provide insights into mechanisms underlying depressive symptoms in diabetes and might open new therapeutic avenues.The trial registration number of the study is NCT01055093.

Identification of circulating risk biomarkers for cognitive decline in a large community-based population in Chongqing China

INTRODUCTION

This study aims to investigate the relationship between blood-based pathologies and established risk factors for cognitive decline in the community-based population of Chongqing, a region with significant aging.

METHODS

A total of 26,554 residents aged 50 years and older were recruited. Multinomial logistic regression models were applied to assess the risk factors of cognition levels. Propensity score matching and linear mixed effects models were used to evaluate the relationship between key risk factors and the circulating biomarkers.

RESULTS

Shared and distinct risk factors for MCI and dementia were identified. Age, lower education, medical history of stroke, hypertension, and epilepsy influenced mild cognitive impairment (MCI) progression to dementia. Correlations between key risk factors and circulating neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), amyloid β protein (Aβ)40, and Aβ42/Aβ40 ratio suggest underlying mechanisms contributing to cognitive impairment.

DISCUSSION

The common and distinct risk factors across cognitive decline stages emphasize the need for tailored interventions. The correlations with blood biomarkers provide insights into potential management targets.

HIGHLIGHTS

From a large community-based cohort study on the residents in Chongqing, we have identified that mild cognitive impairment (MCI) and dementia share several common risk factors, including age, female gender, rural living, lower education levels, and a medical history of stroke. However, each condition also has its own unique risk factors. Several factors contribute to the progression of MCI into dementia including age, education levels, occupation, and a medical history of hypertension and epilepsy. We discover the correlations between the risk factors for dementia and blood biomarkers that indicate the presence of axonal damage, glial activation, and Aβ pathology.

Diabetes exerts a causal impact on the nervous system within the right hippocampus: substantiated by genetic data

INTRODUCTION

Diabetes and neuronal loss in the hippocampus have been observed to be correlated in several studies; however, the exact causality of this association remains uncertain. This study aims to explore the potential causal relationship between diabetes and the hippocampal nervous system.

METHODS

We utilized the two-sample Mendelian randomization (MR) analysis to investigate the potential causal connection between diabetes and the hippocampal nervous system. The summary statistics of Genome-wide association study (GWAS) for diabetes and hippocampus neuroimaging measurement were acquired from published GWASs, all of which were based on European ancestry. Several two-sample MR analyses were conducted in this study, utilizing inverse-variance weighted (IVW), MR Egger, and Weight-median methods. To ensure the reliability of the results and identify any horizontal pleiotropy, sensitivity analyses were undertaken using Cochran's Q test and the MR-PRESSO global test.

RESULTS

Causal associations were found between diabetes and the nervous system in the hippocampus. Type 1 and type 2 diabetes were both identified as having adverse causal connections with the right hippocampal nervous system. This was supported by specific ranges of IVW-OR values (P < 0.05). The consistency of the sensitivity analyses further reinforced the main findings, revealing no significant heterogeneity or presence of horizontal pleiotropy.

CONCLUSIONS

This study delved into the causal associations between diabetes and the hippocampal nervous system, revealing that both type 1 and type 2 diabetes have detrimental effects on the right hippocampal nervous system. Our findings have significant clinical implications as they indicate that diabetes may play a role in the decline of neurons in the right hippocampus among European populations, often resulting in cognitive decline.

Study on the mechanism on Yi-guan-jian decoction alleviating cognitive dysfunction in type 2 diabetes mellitus

ETHNOPHARMACOLOGICAL RELEVANCE

Yi-guan-jian decoction (YGJ) is a traditional Chinese medicine prescription commonly used for treating syndromes associated with Yin deficiency in the liver and kidney, as well as Qi-obstructed in liver.

AIM OF THE STUDY

YGJ has shown potential alleviating cognitive dysfunction in type 2 diabetes mellitus (T2DM). However, the precise mechanisms are not yet fully understood. This study aims to reveal the mechanism by which YGJ alleviates cognitive dysfunction in T2DM.

MATERIALS AND METHODS

Various doses of YGJ were administered to T2DM rats with cognitive dysfunction for 8 weeks. The positive control group received a combination of metformin and memantine. Cognitive function was assessed in T2DM rats using the Morris water maze test during treatment. Changes in gut microbiota and bile acids in the intestine were evaluated, and their interactions analyzed. Additionally, this study also evaluated the expressions of inflammatory markers (IL-1β,TNF-α, IL-16, IL-18 and CRP protein), Tau protein, neurotransmitter (5-HT and GABA), and bile acid receptor (FXR, PXR, VDR, and TGR5).

RESULTS

YGJ significantly alleviated insulin resistance and hyperlipidemia, reduce the levels of inflammatory factors in serum and hippocampus, and decreased mortality in T2DM rats. The Morris water maze test indicated that YGJ reduced the escape latency and increased platform crossing frequency, thereby improving cognitive function in T2DM rats. Furthermore, YGJ regulated the abundance of microorganisms associated with bile acid metabolism, including Romboutsia, Bacteroides, Turicibacter, Blautia, and Ruminococcus, thus regulating bile acid metabolism in T2DM rats. Additionally, YGJ also regulated bile acid metabolism by regulating intestinal FXR, PXR, VDR and TRG5 receptors.

CONCLUSION

YGJ can alleviate glucose homeostasis, insulin sensitivity, lipid metabolism, neuroinflammation, cognitive function, as well as remodel intestinal flora and BA composition in CDT2DM rats, which is a potential complementary and alternative therapy for the prevention and treatment of CDT2DM. These effects may be associated that YGJ regulates the structure of intestinal flora and BA metabolism, and inhibits intestinal BA receptors FXR, PXR, TGR5, and VDR.

Characterization of cognitive decline in long-duration type 1 diabetes by cognitive, neuroimaging, and pathological examinations

BACKGROUNDWe aimed to characterize factors associated with the under-studied complication of cognitive decline in aging people with long-duration type 1 diabetes (T1D).METHODSJoslin "Medalists" (n = 222; T1D ≥ 50 years) underwent cognitive testing. Medalists (n = 52) and age-matched nondiabetic controls (n = 20) underwent neuro- and retinal imaging. Brain pathology (n = 26) was examined. Relationships among clinical, cognitive, and neuroimaging parameters were evaluated.RESULTSCompared with controls, Medalists had worse psychomotor function and recall, which associated with female sex, lower visual acuity, reduced physical activity, longer diabetes duration, and higher inflammatory cytokines. On neuroimaging, compared with controls, Medalists had significantly lower total and regional brain volumes, equivalent to 9 years of accelerated aging, but small vessel disease markers did not differ. Reduced brain volumes associated with female sex, reduced psychomotor function, worse visual acuity, longer diabetes duration, and higher inflammation, but not with glycemic control. Worse cognitive function, lower brain volumes, and diabetic retinopathy correlated with thinning of the outer retinal nuclear layer. Worse baseline visual acuity associated with declining psychomotor function in longitudinal analysis. Brain volume mediated the association between visual acuity and psychomotor function by 57%. Brain pathologies showed decreased volumes, but predominantly mild vascular or Alzheimer's-related pathology.CONCLUSION To our knowledge, this is the first comprehensive study of cognitive function, neuroimaging, and pathology in aging T1D individuals demonstrated that cognitive decline was related to parenchymal rather than neurovascular abnormalities, unlike type 2 diabetes, suggestive of accelerated aging in T1D. Improving visual acuity could perhaps be an important preventive measure against cognitive decline in people with T1D.FUNDINGThe Beatson Foundation, NIH/NIDDK grants 3P30DK036836-34S1 and P30DK036836-37, and Mary Iacocca fellowships.

Trichosanthes kirilowii Maxim. Polysaccharide attenuates diabetes through the synergistic impact of lipid metabolism and modulating gut microbiota

Polysaccharide, a chain of sugars bound by glycosidic bonds, have a wide range of physiological activities, including hypoglycemic activity. In present study, we established T2DM mice models to explore the effects and mechanism of Trichosanthes kirilowii Maxim polysaccharide (TMSP1) on high-fat diet/streptozotocin (HF-STZ) induced diabetes mice. The results showed that high-fat diet significantly increased the oral glucose tolerance test (OGTT), viscera index, oxidative stress, impaired glucose tolerance, decreased body weight, immune response and short-chain fatty acid (SCFAs) content, and disrupted the balance of intestinal flora structure. However, after 6 weeks of TMSP1 intervention decreased lipid accumulation, ameliorated gut microbiota dysbiosis by increasing SCFAs-producing bacteria and mitigated intestinal inflammation and oxidative stress. Moreover, TMSP1 significantly restored the integrity of the intestinal epithelial barrier and mucus barrier. The results of fecal microbiota transplantation confirmed that TMSP1 exerted hypoglycemic effect through regulating intestinal flora to a certain extent. Collectively, the findings revealed TMSP1 intervention inhibits hyperglycemia by improving gut microbiota disorder, lipid metabolism, and inflammation. Hence, TMSP1 may be an effective measure to ameliorate HF-STZ induced diabetes.

Relationships Between APOE, Type 2 Diabetes, and Cardiovascular Disease in Postmenopausal Women

BACKGROUND

The apolipoprotein E (APOE) ε4 allele, type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD) are well-established risk factors for dementia. Relationships between APOE and incidence of T2DM and CVD are not fully understood but may shed light on the mechanisms underlying dementia pathogenesis.

METHODS

Postmenopausal women (N = 6 795) from the Women's Health Initiative hormone therapy clinical trial with APOE genotyping and no prior diagnosis of T2DM or CVD were included. We examined associations of APOE status (APOE2+ [ε2/ε2, ε2/ε3], APOE3 [ε3/ε3], and APOE4+ [ε4/ε4, ε3/ε4] carriers) with incidence of T2DM, coronary heart disease, stroke, and total CVD events using Cox regression. CVD outcomes were examined in baseline non-statin users and adjusted for statin initiation over follow-up to account for possible confounding by statins.

RESULTS

Among all participants (mean age 66.7 ± 6.5 years, 100% non-Hispanic White), 451 (6.6%) were using statins at baseline. Over the follow-up (mean 14.9 and 16.0 years for T2DM and CVD, respectively), 1 564 participants developed T2DM and 1 578 developed CVD. T2DM incidence did not differ significantly by APOE status (ps ≥ .09). Among non-statin users, APOE4+ had higher incidence of total CVD (hazard ratio [95% confidence interval] = 1.18 [1.02-1.38], p = .03) compared with APOE3 carriers, but risks for coronary heart disease (1.09 [0.87-1.36], p = .47) and stroke (1.14 [0.91-1.44], p = .27) were not significantly elevated when examined individually. CVD outcomes did not differ between APOE2+ and APOE3 carriers (ps ≥ 0.11).

CONCLUSIONS

T2DM risk did not differ by APOE status among postmenopausal women, but APOE4+ carriers not using statins had an increased risk of total CVD events.

Diabetes-related cognitive impairment: Mechanisms, symptoms, and treatments

Background

Diabetes-related cognitive impairment is increasingly recognized as a significant complication, profoundly impacting patients' quality of life. This review aims to examine the pathophysiological mechanisms, clinical manifestations, risk factors, assessment and diagnosis, management strategies, and future research directions of cognitive impairment in diabetes.

Methodology

A comprehensive literature search was conducted using PubMed, Medline, and other medical databases to identify, review, and evaluate published articles on cognitive impairment in diabetes. The search focused on studies examining pathophysiology, clinical presentations, risk factors, diagnostic approaches, and management strategies.

Results

The review of current literature revealed that chronic hyperglycemia, insulin resistance, and vascular factors are major contributing factors to cognitive deficits in diabetes. Clinical manifestations include impairments in attention, memory, executive function, visuospatial abilities, and language. Risk factors encompass disease duration, glycemic control, presence of complications, age, education level, and comorbidities. Assessment tools include cognitive screening instruments, neuropsychological testing, and neuroimaging techniques. Management strategies involve glycemic control optimization, lifestyle modifications, cognitive training, and pharmacological interventions.

Conclusion

This review highlights the significant prevalence and impact of cognitive impairment in diabetes, resulting from complex metabolic and vascular disturbances. Early detection and multifaceted interventions are crucial for preserving cognitive function and improving patient outcomes. Future research should focus on neuroprotective strategies, biomarker identification, and personalized approaches. Collaborative efforts between clinicians and researchers are essential to effectively address this growing healthcare challenge and enhance the quality of life for individuals with diabetes-related cognitive impairment.

Differences in brain spindle density during sleep between patients with and without type 2 diabetes

BACKGROUND

Sleep spindles may be implicated in sensing and regulation of peripheral glucose. Whether spindle density in patients with type 2 diabetes mellitus (T2DM) differs from that of healthy subjects is unknown.

METHODS

Our retrospective analysis of polysomnography (PSG) studies identified 952 patients with T2DM and 952 sex-, age- and BMI-matched control subjects. We extracted spindles from PSG electroencephalograms and used rank-based statistical methods to test for differences between subjects with and without diabetes. We also explored potential modifiers of spindle density differences. We replicated our analysis on independent data from the Sleep Heart Health Study.

RESULTS

We found that patients with T2DM exhibited about half the spindle density during sleep as matched controls (P < 0.0001). The replication dataset showed similar trends. The patient-minus-control paired difference in spindle density for pairs where the patient had major complications were larger than corresponding paired differences in pairs where the patient lacked major complications, despite both patient groups having significantly lower spindle density compared to their respective control subjects. Patients with a prescription for a glucagon-like peptide 1 receptor agonist had significantly higher spindle density than those without one (P ≤ 0.03). Spindle density in patients with T2DM monotonically decreased as their highest recorded HbA1C level increased (P ≤ 0.003).

CONCLUSIONS

T2DM patients had significantly lower spindle density than control subjects; the size of that difference was correlated with markers of disease severity (complications and glycemic control). These findings expand our understanding of the relationships between sleep and glucose regulation.

Cortical Gyrification and Cognitive Decline in the Human Brain With Type 2 Diabetes Mellitus

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is linked to abnormal brain structure and cognitive dysfunction. However, there is a lack of studies conducted to assess the impact of diabetes on cortical gyrification and cognition. The aim of this cross-sectional study was to assess the potential negative effects of glucose metabolism levels on cognition and cortical gyrification in T2DM.

METHODS

The current study comprised 83 patients with T2DM and 60 individuals with normal glucose metabolism (NGM). The calculation of the local gyrification index (LGI) was performed utilizing the FreeSurfer software. Subsequently, between-group differences were examined through the utilization of analysis of covariance. Multivariable linear regression and mediation models were employed to investigate the relationships among LGI, glucose metabolism and cognition.

RESULTS

Our study found that the mean LGI of the entire brain in individuals with T2DM was lower than that of NGM, and these significant hypogyria were mainly located in the bilateral temporal lobes, including the left superior temporal cortex, left transverse temporal cortex, and bilateral temporal pole, with the greatest effect size in the left temporal pole (p = 5.7×10-7, Cohen's f2 = 0.169). In addition, the relationship between fasting blood glucose and working memory was mediated by the LGI in the right temporal pole.

CONCLUSION

Our experiment suggests that the decreased LGI in the right temporal pole explains poorer working memory performance in patients with T2DM.

Factors associated with cognitive impairment in patients with atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is associated with an increased risk of cognitive impairment. Therefore, exploring factors which may be associated with cognitive impairment is important. Correspondingly, this study aimed to systematically evaluate factors associated with cognitive impairment in AF patients by synthesizing relevant evidence.

METHODS

A database search of the PubMed, Embase, Cochrane Library, Web of Science, CBM, CNKI, Wanfang, and VIP databases was conducted from inception until December 21, 2023. The effect size was expressed as a combined odds ratio (OR) and 95 % confidence interval (95 % CI). The heterogeneity was qualitatively analyzed by Cochran's Q test and quantified by the I2 statistic.

RESULTS

A total of 7,128 studies were identified from the 8 databases, and 39 studies of 3,491,423 participants were included. A meta-analysis was performed on 19 influencing factors. Advanced age (OR=1.38, 95 % CI: 1.11-1.71), female sex (OR=2.19, 95 % CI: 1.18-4.06), smoking (OR=2.44, 95 % CI: 1.24-4.80), hypertension (OR=1.61, 95 % CI: 1.27-2.03), diabetes (OR=1.42, 95 % CI: 1.20-1.67), and hearing impairment (OR=1.37, 95 % CI: 1.05-1.81) were risk factors for cognitive impairment. A higher education level (OR=0.57, 95 % CI: 0.46-0.72), oral anticoagulants (OR=0.61, 95 % CI: 0.48-0.78), novel oral anticoagulants (OR=0.63, 95 % CI: 0.54-0.73), warfarin (OR=0.55, 95 % CI: 0.39-0.79), novel oral anticoagulants relative to warfarin (OR=0.88, 95 % CI: 0.81-0.97), catheter ablation (OR=0.74, 95 % CI: 0.58-0.94) and exercise (OR=0.66, 95 % CI: 0.61-0.72) were protective factors for cognitive impairment.

CONCLUSIONS

Age, sex, education level, smoking, exercise, hypertension, diabetes, hearing impairment, anticoagulation therapy, and catheter ablation were associated with cognitive impairment in AF patients.

The double life of glucose metabolism: brain health, glycemic homeostasis, and your patients with type 2 diabetes

The maintenance of cognitive function is essential for quality of life and health outcomes in later years. Cognitive impairment, however, remains an undervalued long-term complication of type 2 diabetes by patients and providers alike. The burden of sustained hyperglycemia includes not only cognitive deficits but also the onset and progression of dementia-related conditions, including Alzheimer's disease (AD). Recent research has shown that the brain maintains an independent glucose "microsystem"-evolved to ensure the availability of fuel for brain neurons without interruption by transient hypoglycemia. When this milieu is perturbed, brain hyperglycemia, brain glucotoxicity, and brain insulin resistance can ensue and interfere with insulin signaling, a key pathway to cognitive function and neuronal integrity. This newly understood brain homeostatic system operates semi-autonomously from the systemic glucoregulatory apparatus. Large-scale clinical studies have shown that systemic dysglycemia is also strongly associated with poorer cognitive outcomes, which can be mitigated through appropriate clinical management of plasma glucose levels. Moreover, these studies demonstrated that glucose-lowering agents are not equally effective at preventing cognitive dysfunction. Glucagon-like peptide-1 (GLP-1) receptor analogs and sodium glucose cotransporter 2 inhibitors (SGLT2is) appear to afford the greatest protection; metformin and dipeptidyl peptidase 4 inhibitors (DPP-4is) also significantly improved cognitive outcomes. Sulfonylureas (SUs) and exogenous insulin, on the other hand, do not provide the same protection and may actually worsen cognitive outcomes. In the creation of a treatment plan, comorbid cognitive conditions should be considered. These efficacious treatments create a new gold standard of managing hyperglycemia-one which is consistent with the "complication-centric prescribing" mandates issued in type 2 diabetes treatment guidelines. The increasing longevity enjoyed by our populace places the onus on clinical care to play the "long game" in using targeted treatments for glucose control in patients with, or at risk for, cognitive decline to maintain cognitive wellness later in life. This article reviews critical emerging data for scientists and trialists and translates new enhancements in patient care for practitioners.

The Protective Role of Vitamin K in Aging and Age-Related Diseases

Aging is an inevitable aspect of life, but age-related diseases are not an inseparable part of the aging process, and their risk can be reduced through a healthy lifestyle. Vitamin K has a broader impact than just blood clotting, and yet it remains overshadowed by other vitamins and underestimated by both doctors and consumers. Vitamin K (VK) is a multifunctional micronutrient with anti-inflammatory and antioxidant properties, whose deficiency may cause age-related diseases such as cardiovascular diseases, neurodegenerative diseases and osteoporosis. There is a growing body of evidence supporting the role of vitamin K as a protective nutrient in aging and inflammation. This review summarizes the current knowledge regarding the molecular aspects of the protective role of vitamin K in aging and age-related diseases and its clinical implications.

Insulin-resistance as a modifiable pathway to cognitive dysfunction in schizophrenia: A systematic review

BACKGROUND

Cognitive deficits are difficult to treat and negatively influence quality of life and functional outcomes of persons with schizophrenia. In the last twenty years, extensive literature demonstrated that persons with diabetes and insulin resistance (IR) also display cognitive deficits. Being type 2 diabetes (T2DM) and IR highly frequent in persons with schizophrenia, it is plausible to hypothesize that these conditions might play a role in determining dyscognition. If that is the case, acting on glucose dysmetabolism may eventually improve cognitive functioning. This review aims at: 1. evaluating the association between IR or T2DM and cognitive dysfunction in schizophrenia; 2. reviewing the evidence that pharmacological treatment of IR or T2DM may improve dyscognition in schizophrenia.

METHODS

Two systematic searches were conducted in PubMed, PsycInfo, and Scopus. We followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines.

RESULTS

From the first search we included 17 studies, 8 on the effects of T2DM and 9 on the effects of IR-other prediabetes measures on cognition in persons with schizophrenia. From the second search we included 12 studies investigating the effect on cognition of glucose (4 studies), insulin (2 studies), metformin (2 studies), PPAR-γ agonists (2 studies), GLP-1 agonist (1 study), bromocriptine (1 study).

CONCLUSIONS

T2DM was associated with worse cognitive function in persons with schizophrenia, while IR was less strongly associated with cognitive dysfunction. Evidence regarding the efficacy of glucose-lowering medications on cognition in schizophrenia is inconclusive, yet methodological issues likely contribute to explain conflicting results.

Brain-immune interactions: implication for cognitive impairments in Alzheimer's disease and autoimmune disorders

Progressive memory loss and cognitive dysfunction, encompassing deficits in learning, memory, problem solving, spatial reasoning, and verbal expression, are characteristics of Alzheimer's disease and related dementia. A wealth of studies has described multiple roles of the immune system in the development or exacerbation of dementia. Individuals with autoimmune disorders can also develop cognitive dysfunction, a phenomenon termed "autoimmune dementia." Together, these findings underscore the pivotal role of the neuroimmune axis in both Alzheimer's disease and related dementia and autoimmune dementia. The dynamic interplay between adaptive and innate immunity, both in and outside the brain, significantly affects the etiology and progression of these conditions. Multidisciplinary research shows that cognitive dysfunction arises from a bidirectional relationship between the nervous and immune systems, though the specific mechanisms that drive cognitive impairments are not fully understood. Intriguingly, this reciprocal regulation occurs at multiple levels, where neuronal signals can modulate immune responses, and immune system-related processes can influence neuronal viability and function. In this review, we consider the implications of autoimmune responses in various autoimmune disorders and Alzheimer's disease and explore their effects on brain function. We also discuss the diverse cellular and molecular crosstalk between the brain and the immune system, as they may shed light on potential triggers of peripheral inflammation, their effect on the integrity of the blood-brain barrier, and brain function. Additionally, we assess challenges and possibilities associated with developing immune-based therapies for the treatment of cognitive decline.

Trajectories of cognitive function and frailty in older adults in China: a longitudinal study

Background

Cognitive impairment and frailty are common issues in older adults. Understanding the co-development trajectories of these conditions can provide valuable sights for early detection and intervention in high-risk individuals.

Objectives

This study aims to identify the co-development of cognitive function and frailty and explore the associated characteristics.

Methods

We analyzed data from 8,418 individuals aged 55 years and above who participated in the China Health and Retirement Longitudinal Survey between 2011 and 2018. Group-based dual trajectory modeling and logistic regression were used to identify trajectory groups and assess associations with risk factors.

Results

Two distinct dual trajectories were identified: "Consistently Robust" group (76.12%) and "Consistently Severe" group (23.88%). Factors such as being female, older age, lower levels of education, residing in rural areas, being unmarried, and having comorbidities such as hypertension, diabetes, complete tooth loss, vision impairment, or hearing impairment were associated with a higher likelihood of being assigned to the "Consistently Severe" group.

Conclusion

Our findings suggest a co-development pattern between cognitive function and frailty in Chinese older adults aged 55 years and above. While cognitive impairment may be irreversible, frailty is a condition that can be potentially reversed. Early detecting is crucial in preventing cognitive decline, considering the shared trajectory of these conditions.

Hippocampal warburg effect mediates hydrogen sulfide-ameliorated diabetes-associated cognitive dysfunction: Involving promotion of hippocampal synaptic plasticity

Our previous studies have reported that hydrogen sulfide (H2S) has ability to improve diabetes-associated cognitive dysfunction (DACD), but the exact mechanisms remain unknown. Recent research reveals that Warburg effect is associated with synaptic plasticity which plays a key role in cognition promotion. Herein, the present study was aimed to demonstrate whether hippocampal Warburg effect contributes to H2S-ameliorated DACD and further explore its potential mechanism. We found that H2S promoted the hippocampal Warburg effect and inhibited the OxPhos in the hippocampus of STZ-induced diabetic rats. It also improved the hippocampal synaptic plasticity in STZ-induced diabetic rats, as evidenced by the change of microstructures and the expression of different key-enzymes. Furthermore, inhibited hippocampal Warburg effect induced by DCA markedly abolished the improvement of H2S on synaptic plasticity in the hippocampus of STZ-induced diabetic rats. DCA blocked H2S-attenuated the cognitive dysfunction in STZ-induced diabetic rats, according to the Y-maze, Novel Objective Recognition, and Morris Water Maze tests. Collectively, these findings indicated that the hippocampal Warburg effect mediates H2S-ameliorated DACD by improving hippocampal synaptic plasticity.

Distinct Hippocampal Expression Profiles of lncRNAs in Obese Type 2 Diabetes Mice Exhibiting Cognitive Impairment

Cognitive dysfunction has been accepted as a possible complication of type 2 diabetes (T2D), but few studies revealed the potential roles of Long non‑coding RNAs (lncRNAs) in cognitive dysfunction in T2D. The current research aims to demonstrate the specific expression patterns of lncRNA-mRNA in the hippocampi of T2D db/db mice exhibiting cognitive impairment. In this study, the results from behavioral tests showed that T2D db/db mice displayed short-term and spatial working memory deficits compared to db/m mice. Furthermore, western blot analysis demonstrated that compared with db/m mice, p-GSK3β (ser9) protein levels were markedly elevated in T2D db/db mice (P < 0.01). In addition, though not statistically significant, the ratio of p-Tau (Ser396) to Tau 46, α-Synuclein expression, and p-GSK3α (ser21) expression were also relatively higher in T2D db/db mice than in db/m mice. The microarray profiling revealed that 75 lncRNAs and 26 mRNAs were dysregulated in T2D db/db mice (> 2.0 fold change, P < 0.05). GO analysis demonstrated that the differentially expressed mRNAs participated in immune response, extracellular membrane-bounded organelle, and extracellular region. KEGG analysis revealed that the differentially expressed mRNAs were mainly involved in one carbon pool by folate, glyoxylate and dicarboxylate metabolism, autophagy, glycine, serine and threonine metabolism, and B cell receptor signaling pathway. A lncRNA‑mRNA coexpression network containing 71 lncRNAs and 26 mRNAs was built to investigate the interaction between lncRNA and mRNA. Collectively, these results revealed the differential hippocampal expression profiles of lncRNAs in T2D mice with cognitive dysfunction, and the findings from this study provide new clues for exploring the potential roles of lncRNAs in the pathogenesis of cognitive dysfunction in T2D.

PM2.5 Exposure as a Risk Factor for Optic Nerve Health in Type 2 Diabetes Mellitus

(1) Objective: This study investigated the relationship between long-term particulate matter (PM2.5) exposure and optic disc parameters-vertical cup-to-disc ratio (vCDR), vertical optic disc diameter (vDD), and vertical optic cup diameter (vCD)-in patients with type 2 diabetes mellitus (T2DM). (2) Methods: A cross-sectional analysis was conducted using data from 65,750 T2DM patients in the 2017-2018 Shanghai Cohort Study of Diabetic Eye Disease (SCODE). Optic disc parameters were extracted from fundus images, and PM2.5 exposure was estimated using a random forest model incorporating satellite and meteorological data. Multivariate linear regression models were applied, adjusting for confounders including age, gender, body mass index, blood pressure, glucose, time of T2DM duration, smoking, drinking, and physical exercise. (3) Results: A 10 μg/m3 increase in PM2.5 exposure was associated with significant reductions in vCDR (-0.008), vDD (-42.547 μm), and vCD (-30.517 μm) (all p-values < 0.001). These associations persisted after sensitivity analyses and adjustments for other pollutants like O3 and NO2. (4) Conclusions: Long-term PM2.5 exposure is associated with detrimental changes in optic disc parameters in patients with T2DM, suggesting possible optic nerve atrophy. Considering the close relationship between the optic nerve and the central nervous system, these findings may also reflect broader neurodegenerative processes.

Cognitive Disorders in Type 1 Diabetes: Role of Brain Glucose Variation, Insulin Activity, and Glucocorticoid Exposure

BACKGROUND

The number of patients with type 2 diabetes (T2D) and type 1 diabetes (T1D) is on the rise, partly due to a global increase in new T1D cases among children. Beyond the well-documented microvascular and macrovascular complications, there is now substantial evidence indicating that diabetes also impacts the brain, leading to neuropsychological impairments. The risk of developing neuropsychiatric symptoms is notably higher in childhood due to the ongoing maturation of the brain, which makes it more susceptible to damage. Despite this awareness, the specific effects of diabetes on cognitive function remain poorly understood.

SUMMARY

This review synthesizes literature on the impact of diabetes on cognition and its relationship with brain structural changes. It presents data and hypotheses to explain how T1D contributes to cognitive dysfunction, with a particular focus on children and adolescents. The emphasis on the pediatric population is intentional, as young diabetic patients typically have fewer comorbidities, reducing confounding factors and simplifying the investigation of cognitive alterations.

KEY MESSAGE

We examine the roles of hypo- and hyperglycemia, as well as the emerging role of glucocorticoids in the development of neuropsychological disorders. When specific mechanisms related to T1D are available, they are highlighted; otherwise, data and hypotheses applicable to both T1D and T2D are discussed.

Assessing different brain oxygenation components in elderly patients under propofol or sevoflurane anesthesia: A randomized controlled study

STUDY OBJECTIVE

Elderly patients undergoing pathophysiological changes necessitate clinical tools for cerebral monitoring. This prospective randomized controlled study aimed to explore how cerebral monitoring using Δo2Hbi, ΔHHbi, and ΔcHbi manifests in elderly patients under either propofol or sevoflurane anesthesia.

DESIGN

Single-center, prospective, randomization.

SETTING

A single tertiary hospital (Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University of Korea).

PATIENTS

Enrolled 100 patients scheduled for urologic surgery under general anesthesia. Inclusion criteria were (a) age 70-80 years, (b) American Society of Anesthesiologists (ASA) physical status I-II.

INTERVENTION

Patients were double-blind randomized to receive propofol-based or sevoflurane anesthesia. Cerebral oximetry-related parameters were measured at 5, 10, 15, 20, and 30 min in a setting devoid of surgery-related factors.

MEASUREMENTS

The primary outcome focused on the Δo2Hbi pattern in the left and right sides within the propofol and sevoflurane groups.

MAIN RESULTS

We analyzed 100 patients, 50 patients in each group. In the propofol group, the left Δo2Hbi decreased from 1.4 (3.7) at 5 min to -0.1 (1.8) at 30 min (P < 0.0001), and the right Δo2Hbi decreased from 2.9 (4.2) at 5 min to -0.06 (2.3) at 30 min (P < 0.0001). In the sevoflurane group, the left Δo2Hbi decreased from 1.1 (3.4) at 5 min to -1.4 (4.4) at 30 min (P < 0.0001), and the right Δo2Hbi decreased from 2.0 (3.2) at 5 min to -1.2 (3.9) at 30 min (P < 0.0001). There were no significant differences between the two groups. ΔHHbi did not exhibit significant changes after an initial decrease at 5 min and showed no significant differences between the two groups.

CONCLUSIONS

In cerebral oximetry, Δo2Hbi and ΔHHbi could emerge as a valuable approach for discerning changes in the underlying baseline status of the brain in elderly patients during anesthesia.

Neurotoxic effects of type II-diabetes mellitus and the possible preventive effects of olive leaves supplement in male rats

Background

Diabetes mellitus (DM) is a common metabolic disorder with well-known serious secondary complications. It is also associated with central nervous system damage. This damage is characterized by impairments in brain functions, with neurochemical and structural abnormalities.

Aim

The study was conducted to clarify the neuroprotective effects of olive leaf supplements on the brain and brain histological structure of diabetic adult rats.

Methods

Thirty adult male rats were allocated into three groups, the first group (CC), received an oral supplement containing olive leaves supplements (OLS) and served as a control; in the other group , DM was induced in these animals and left for 40 days; and the third group was DM+OL, which induced DM, then treated with oral OLS for 40 days. The investigation included serum glycemic index measurements, in addition to the level of malondialdehyde (MDA), glutathione (GSH), dopamine (DOP), acetylcholinesterase (AchE) in brain tissue, and histopathology of brain and pancreas.

Results

We demonstrated a significant increase in glycemic index measurements in diabetic groups (DM, DM+OL) at the beginning of a trial; however, the same parameters were significantly decreased after treatment with OLS in only the DM+OL group after 40 days. The study also showed differences in the levels of MDA, and GSH, in the diabetic groups, which returned to normal levels after being treated with OLS. Moreover, AchE and DOP exhibited a significant decline in diabetic rats. However, OLS induced a considerable rise in these neurotransmitters after treatment with it in the DM+OL group. The histopathological section of the pancreas and brain showed histopathological changes in DM groups; whereas, the tissue was shielded from chemical damage from DM by the OLS treatment in DM+OL animals.

Conclusion

Overall, diabetes impairs glucose hemostasis by affecting glucose concentration, insulin level, and insulin resistance. However, olive leaf supplements restored the glucose hemostasis close to normal in diabetic rats. Furthermore, diabetes affects neurotransmitters by increasing the level of oxidative stress in brain tissue, and brain cell damage. Nevertheless, olive leaf supplements can ameliorate DM harmful effects by retrieving the normal oxidative environment in the brain.

High Mobility Group Box Protein (HMGB1): A Potential Therapeutic Target for Diabetic Encephalopathy

HMGB (high mobility group B) is one of the ubiquitous non-histone nuclear protein superfamilies that make up the HMG (high mobility group) protein group. HMGB1 is involved in a variety of physiological and pathological processes in the human body, including a structural role in the cell nucleus as well as replication, repair, DNA transcription, and assembly of nuclear proteins. It functions as a signaling regulator in the cytoplasm and a pro-inflammatory cytokine in the extracellular environment. Among several studies, HMGB1 protein is also emerging as a crucial factor involved in the development and progression of diabetic encephalopathy (DE) along with other factors such as hyperglycaemia-induced oxidative and nitrosative stress. Diabetes' chronic side effect is DE, which manifests as cognitive and psychoneurological dysfunction. The HMGB1 is released outside to the extracellular medium in diabetes condition through active or passive routes, where it functions as a damage-associated molecular pattern (DAMP) molecule to activate several signaling pathways by interacting with receptors for advanced glycosylation end-products (RAGE)/toll like receptors (TLR). HMGB1 reportedly activates inflammatory pathways, disrupts the blood-brain barrier, causes glutamate toxicity and oxidative stress, and promotes neuroinflammation, contributing to the development of cognitive impairment and neuronal damage which is suggestive of the involvement of HMGB1 in the enhancement of the diabetes-induced encephalopathic condition. Additionally, HMGB1 is reported to induce insulin resistance, further exacerbating the metabolic dysfunction associated with diabetes mellitus (DM). Thus, the present review explores the possible pathways associated with DM-induced hyperactivation of HMGB1 ultimately leading to DE.

Cannabidiol modulates contextual fear memory consolidation in animals with experimentally induced type-1 diabetes mellitus

OBJECTIVES

In view of the neuroprotective characteristic of cannabidiol (CBD) and its beneficial action on aversive memory in non-diabetic animals, we aimed to investigate in animals with experimentally induced type-1 diabetes mellitus (T1DM) whether CBD treatment would be able to impair the contextual fear memory consolidation, its generalisation and whether the effect would be lasting. We also investigated the CBD effect on anxiety-like responses.

METHODS

After T1DM induction, animals received single or more prolonged treatment with CBD and were submitted to the contextual fear conditioning test. As expression of activity-regulated cytoskeletal-associated (Arc) protein is necessary for memory consolidation, we evaluated its expression in the dorsal hippocampus (DH). For evaluating anxiety-related responses, animals were submitted to the elevated plus maze test (EPMT), in which the time and number of entries in the open arms were used as anxiety index.

RESULTS

A single injection of CBD impaired the contextual fear memory consolidation and its generalisation, which was evaluated by exposing the animal in a neutral context. This single injection was able to reduce the elevated expression of Arc in the DH from these animals. Interestingly, more prolonged treatment with CBD also impaired the persistence of context-conditioned fear memory and induced an anxiolytic-like effect, as the treated group spent more time in the open arms of the EPMT.

CONCLUSION

CBD interferes with contextual fear memory and the dosage regimen of treatment seems to be important. Moreover, we cannot rule out the involvement of emotional aspects in these processes related to fear memory.

Droplet Microfluidics Powered Hydrogel Microparticles for Stem Cell-Mediated Biomedical Applications

Stem cell-related therapeutic technologies have garnered significant attention of the research community for their multi-faceted applications. To promote the therapeutic effects of stem cells, the strategies for cell microencapsulation in hydrogel microparticles have been widely explored, as the hydrogel microparticles have the potential to facilitate oxygen diffusion and nutrient transport alongside their ability to promote crucial cell-cell and cell-matrix interactions. Despite their significant promise, there is an acute shortage of automated, standardized, and reproducible platforms to further stem cell-related research. Microfluidics offers an intriguing platform to produce stem cell-laden hydrogel microparticles (SCHMs) owing to its ability to manipulate the fluids at the micrometer scale as well as precisely control the structure and composition of microparticles. In this review, the typical biomaterials and crosslinking methods for microfluidic encapsulation of stem cells as well as the progress in droplet-based microfluidics for the fabrication of SCHMs are outlined. Moreover, the important biomedical applications of SCHMs are highlighted, including regenerative medicine, tissue engineering, scale-up production of stem cells, and microenvironmental simulation for fundamental cell studies. Overall, microfluidics holds tremendous potential for enabling the production of diverse hydrogel microparticles and is worthy for various stem cell-related biomedical applications.

Evaluation of Factors Influencing Postoperative Cognitive Dysfunction in Patients After Cranial Tumor Surgery

BACKGROUND

The authors retrospectively analyzed the perioperative data of 81 patients who underwent cranial tumor surgery to explore the factors influencing POCD in patients after the surgery.

METHODS

The authors evaluated preoperative cognitive dysfunction using the Mini-Mental State Examination (MMSE) score measured. For patients whose cognitive function was normal, the authors retrieved the MMSE score on the seventh day after surgery and compared it to determine whether the patients had POCD. The authors used a univariate logistic regression analysis to analyze the perioperative factors in patients, namely, age, gender, history of underlying diseases, tumor size, peritumoral edema, duration of surgery, blood loss, intraoperative fluid infusion, and type of anesthetic drugs. The authors then performed a multivariate logistic regression analysis for the statistically significant factors.

RESULTS

The authors found that 23 of 81 patients (28.4%) developed POCD. Univariate logistic analysis showed that a history of diabetes mellitus, peritumoral edema, intraoperative blood loss, and anesthetic drugs were the risk factors for patients developing POCD after cranial tumor surgery. Multivariate logistic regression analysis showed that a history of diabetes mellitus, peritumoral edema, and use of ciprofol as the anesthetic drug were independent risk factors for POCD after cranial tumor surgery.

CONCLUSIONS

A history of diabetes mellitus, the degree of brain tumor edema, and the choice of anesthetic drugs significantly influence the occurrence of POCD in patients after cranial tumor surgery.

Oxidative Stress Markers and Na,K-ATPase Enzyme Kinetics Are Altered in the Cerebellum of Zucker Diabetic Fatty fa/fa Rats: A Comparison with Lean fa/+ and Wistar Rats

Type 2 diabetes mellitus has been referred to as being closely related to oxidative stress, which may affect brain functions and brain glucose metabolism due to its high metabolic activity and lipid-rich content. Na,K-ATPase is an essential enzyme maintaining intracellular homeostasis, with properties that can sensitively mirror various pathophysiological conditions such as diabetes. The goal of this study was to determine oxidative stress markers as well as Na,K-ATPase activities in the cerebellum of Zucker diabetic fatty (ZDF) rats depending on diabetes severity. The following groups of male rats were used: Wistar, ZDF Lean (fa/+), and ZDF (fa/fa) rats, arbitrarily divided according to glycemia into ZDF obese (ZO, less severe diabetes) and ZDF diabetic (ZOD, advanced diabetes) groups. In addition to basic biometry and biochemistry, oxidative stress markers were assessed in plasma and cerebellar tissues. The Na, K-ATPase enzyme activity was measured at varying ATP substrate concentrations. The results indicate significant differences in basic biometric and biochemical parameters within all the studied groups. Furthermore, oxidative damage was greater in the cerebellum of both ZDF (fa/fa) groups compared with the controls. Interestingly, Na,K-ATPase enzyme activity was highest to lowest in the following order: ZOD > ZO > Wistar > ZDF lean rats. In conclusion, an increase in systemic oxidative stress resulting from diabetic conditions has a significant impact on the cerebellar tissue independently of diabetes severity. The increased cerebellar Na,K-ATPase activity may reflect compensatory mechanisms in aged ZDF (fa/fa) animals, rather than indicating cerebellar neurodegeneration: a phenomenon that warrants further investigation.

Unveiling Green Synthesis and Biomedical Theranostic paradigms of Selenium Nanoparticles (SeNPs) - A state-of-the-art comprehensive update

The advancements in nanotechnology, pharmaceutical sciences, and healthcare are propelling the field of theranostics, which combines therapy and diagnostics, to new heights; emphasizing the emergence of selenium nanoparticles (SeNPs) as versatile theranostic agents. This comprehensive update offers a holistic perspective on recent developments in the synthesis and theranostic applications of SeNPs, underscoring their growing importance in nanotechnology and healthcare. SeNPs have shown significant potential in multiple domains, including antioxidant, anti-inflammatory, anticancer, antimicrobial, antidiabetic, wound healing, and cytoprotective therapies. The review highlights the adaptability and biocompatibility of SeNPs, which are crucial for advanced disease detection, monitoring, and personalized treatment. Special emphasis is placed on advancements in green synthesis techniques, underscoring their eco-friendly and cost-effective benefits in biosensing, diagnostics, imaging and therapeutic applications. Additionally, the appraisal scrutinizes the progressive trends in smart stimuli-responsive SeNPs, conferring their role in innovative solutions for disease management and diagnostics. Despite their promising therapeutic and prophylactic potential, SeNPs also present several challenges, particularly regarding toxicity concerns. These challenges and their implications for clinical translation are thoroughly explored, providing a balanced view of the current state and prospects of SeNPs in theranostic applications.

Evaluation of Event-Related Potentials in Somatic Diseases - Systematic Review

Many somatic illnesses (e.g. hypertension, diabetes, pulmonary and cardiac diseases, hepatitis C, kidney and heart failure, HIV infection, Sjogren's disease) may impact central nervous system functions resulting in emotional, sensory, cognitive or even personality impairments. Event-related potential (ERP) methodology allows for monitoring neurocognitive processes and thus can provide a valuable window into these cognitive processes that are influenced, or brought about, by somatic disorders. The current review aims to present published studies on the relationships between somatic illness and brain function as assessed with ERP methodology, with the goal to discuss where this field of study is right now and suggest future directions.

Abnormalities in spontaneous brain activity and functional connectivity are associated with cognitive impairments in children with type 1 diabetes mellitus

BACKGROUND

It remains unclear whether alterations in brain function occur in the early stage of pediatric type 1 diabetes mellitus(T1DM). We aimed to examine changes in spontaneous brain activity and functional connectivity (FC) in children with T1DM using resting-state functional magnetic resonance imaging (rs-fMRI), and to pinpoint potential links between neural changes and cognitive performance.

METHODS

In this study, 22 T1DM children and 21 age-, sex-matched healthy controls underwent rs-fMRI. The amplitude of low frequency fluctuations (ALFF) and seed-based FC analysis were performed to examine changes in intrinsic brain activity and functional networks in T1DM children. Partial correlation analyses were utilized to explore the correlations between ALFF values and clinical parameters.

RESULTS

The ALFF values were significantly lower in the lingual gyrus (LG) and higher in the left medial superior frontal gyrus (MSFG) in T1DM children compared to controls. Subsequent FC analysis indicated that the LG had decreased FC with bilateral inferior occipital gyrus, and the left MSFG had decreased FC with right precentral gyrus, right inferior parietal gyrus and right postcentral gyrus in children with T1DM. The ALFF values of LG were positively correlated with full-scale intelligence quotient and age at disease onset in T1DM children, while the ALFF values of left MSFG were positively correlated with working memory scores.

CONCLUSION

Our findings revealed abnormal spontaneous activity and FC in brain regions related to visual, memory, default mode network, and sensorimotor network in the early stage of T1DM children, which may aid in further understanding the mechanisms underlying T1DM-associated cognitive dysfunction.

Association between the geriatric nutritional risk index and cognitive functions in older adults: a cross-sectional study from National Health and Nutrition Examination Survey

Objective

To investigate the associations between the geriatric nutritional risk index (GNRI) with cognitive functions among U.S. older adults. (Patients were classified into two nutrition risk groups based on the GNRI).

Methods

Our analysis utilized data from the cross-sectional National Health and Nutrition Examination Survey (NHANES) conducted between 2011 and 2014. Cognitive function was measured using CERAD test, AFT and DSST. Composite z-scores were obtained by summing test-specific z-scores of the above three cognitive tests and were used to assess the global cognitive function. We employed weighted logistic regression models to evaluate the associations between GNRI and nutritional status (low and high GNRI) with cognitive function among older participants. The non-linear relationship was described using fitted smoothed curves and threshold effect analyses. Subgroup analysis and interaction tests were also conducted.

Results

This study included 2,592 older participants aged 60 years and older. After adjusting for confounding variables, the GNRI was positively associated with AFT (β = 0.05, 95% CI 0.005-0.096, p-value = 0.0285), DSST (β = 0.192, 95% CI 0.078-0.305, p-value = 0.0010) and the composite z-scores (β = 0.027, 95% CI 0.010-0.044, p-value = 0.0024). The results also showed that the high-GNRI group was significantly associated with AFT (β = 0.922, 95% CI 0.166-1.677, p-value = 0.0169), DSST (β = 2.791, 95% CI 0.884-4.698, p-value = 0.0042) and composite z-scores (β = 0.405, 95% CI 0.115-0.695, p-value = 0.0062) likewise had significant positive correlations, using the low-GNRI group as a reference. In addition, inflection points with CERAD and composite z-scores were found at GNRI of 108.016, and 105.371, respectively. Specifically, on the left side of the inflection point GNRI levels were positively correlated with CERAD and composite z-scores (CERAD β = 0.087, 95% CI 0.024-0.150, p-value = 0.0070; composite z-scores β = 0.065, 95% CI 0.040-0.091, p-value <0.0001), while on the right side of the inflection point were significantly negatively associated (CERAD β = -0.295, 95% CI -0.529 to -0.062, p-value = 0.0133, composite z-scores β = -0.050, 95% CI -0.091 to -0.008, p-value = 0.0184).

Conclusion

Lower GNRI was associated with poorer performance in several cognitive domains. Additionally, there was a non-linear positive association between GNRI and cognitive function in normal nutritional states, for excessive GNRI may cause cognitive decline.

Inhibition of ANGPTL8 protects against diabetes-associated cognitive dysfunction by reducing synaptic loss via the PirB signaling pathway

BACKGROUND

Type 2 diabetes mellitus (T2D) is associated with an increased risk of cognitive dysfunction. Angiopoietin-like protein 8 (ANGPTL8) is an important regulator in T2D, but the role of ANGPTL8 in diabetes-associated cognitive dysfunction remains unknown. Here, we explored the role of ANGPTL8 in diabetes-associated cognitive dysfunction through its interaction with paired immunoglobulin-like receptor B (PirB) in the central nervous system.

METHODS

The levels of ANGPTL8 in type 2 diabetic patients with cognitive dysfunction and control individuals were measured. Mouse models of diabetes-associated cognitive dysfunction were constructed to investigate the role of ANGPTL8 in cognitive function. The cognitive function of the mice was assessed by the Barnes Maze test and the novel object recognition test, and levels of ANGPTL8, synaptic and axonal markers, and pro-inflammatory cytokines were measured. Primary neurons and microglia were treated with recombinant ANGPTL8 protein (rA8), and subsequent changes were examined. In addition, the changes induced by ANGPTL8 were validated after blocking PirB and its downstream pathways. Finally, mice with central nervous system-specific knockout of Angptl8 and PirB-/- mice were generated, and relevant in vivo experiments were performed.

RESULTS

Here, we demonstrated that in the diabetic brain, ANGPTL8 was secreted by neurons into the hippocampus, resulting in neuroinflammation and impairment of synaptic plasticity. Moreover, neuron-specific Angptl8 knockout prevented diabetes-associated cognitive dysfunction and neuroinflammation. Mechanistically, ANGPTL8 acted in parallel to neurons and microglia via its receptor PirB, manifesting as downregulation of synaptic and axonal markers in neurons and upregulation of proinflammatory cytokine expression in microglia. In vivo, PirB-/- mice exhibited resistance to ANGPTL8-induced neuroinflammation and synaptic damage.

CONCLUSION

Taken together, our findings reveal the role of ANGPTL8 in the pathogenesis of diabetes-associated cognitive dysfunction and identify the ANGPTL8-PirB signaling pathway as a potential target for the management of this condition.

Beneficial Effects of Echinacoside on Cognitive Impairment and Diabetes in Type 2 Diabetic db/db Mice

INTRODUCTION

Cognitive dysfunction is an important comorbidity of diabetes. Insulin resistance may play a critical role in diabetes-related cognitive impairment. Echinacoside (ECH), a natural phenylethanoid glycoside, is the active component of anti-diabetes prescriptions in traditional Chinese medicine. Its effect on modulating insulin resistance has been confirmed but modulating neurodegenerative disease remains unclear.

METHODS

Db/db mice, a spontaneous type 2 diabetes mode, were intragastrically administered ECH by 300 mg/kg or an equivalent volume of saline. Weight, blood glucose, and insulin resistance index were measured. Morris water maze test was performed to observe the compound effects on cognition. Hippocampal lesions were observed by histochemical analysis.

RESULTS

In db/db mice, ECH alleviated diabetes symptoms, memory loss, and hippocampal neuronal damage. Next, the expression of CD44 and phosphorylated tau was upregulated in diabetic mice. In addition, the insulin receptor substrate-1/phosphatidylinositol 3-kinase /protein kinase B signaling pathway was dysregulated in diabetic mice. All these dysregulations could be reversed by ECH.

DISCUSSION

This study provides theoretical support and experimental evidence for the future application of ECH in diabetic cognition dysfunction treatment, promoting the development of traditional medicines.

Cross-sectional association of continuous glucose monitoring-derived metrics with cerebral small vessel disease in older adults with type 2 diabetes

AIM

To examine cross-sectional associations between continuous glucose monitoring (CGM)-derived metrics and cerebral small vessel disease (SVD) in older adults with type 2 diabetes.

MATERIALS AND METHODS

In total, 80 patients with type 2 diabetes aged ≥70 years were analysed. Participants underwent CGM for 14 days. From the CGM data, we derived mean sensor glucose, percentage glucose coefficient of variation, mean amplitude of glucose excursion, time in range (TIR, 70-180 mg/dl), time above range (TAR) and time below range metrics, glycaemia risk index and high/low blood glucose index. The presence of cerebral SVD, including lacunes, microbleeds, enlarged perivascular spaces and white matter hyperintensities, was assessed, and the total number of these findings comprised the total cerebral SVD score (0-4). Ordinal logistic regression analyses were performed to examine the association of CGM-derived metrics with the total SVD score.

RESULTS

The median SVD score was 1 (interquartile range 0-2). Higher hyperglycaemic metrics, including mean sensor glucose, TAR >180 mg/dl, TAR >250 mg/dl, and high blood glucose index and glycaemia risk index, were associated with a higher total SVD score. In contrast, a higher TIR (per 10% increase) was associated with a lower total SVD score (odds ratio 0.73, 95% confidence interval 0.56-0.95). Glycated haemoglobin, percentage glucose coefficient of variation, mean amplitude of glucose excursions, time below range and low blood glucose index were not associated with total cerebral SVD scores.

CONCLUSIONS

The hyperglycaemia metrics and TIR, derived from CGM, were associated with cerebral SVD in older adults with type 2 diabetes.

Sleep-wake behaviors associated with cognitive performance in middle-aged participants of the Hispanic Community Health Study/Study of Latinos

OBJECTIVES

Many sleep-wake behaviors have been associated with cognition. We examined a panel of sleep-wake/activity characteristics to determine which are most robustly related to having low cognitive performance in midlife. Secondarily, we evaluate the predictive utility of sleep-wake measures to screen for low cognitive performance.

METHODS

The outcome was low cognitive performance defined as being >1 standard deviation below average age/sex/education internally normalized composite cognitive performance levels assessed in the Hispanic Community Health Study/Study of Latinos. Analyses included 1006 individuals who had sufficient sleep-wake measurements about 2years later (mean age=54.9, standard deviation= 5.1; 68.82% female). We evaluated associations of 31 sleep-wake variables with low cognitive performance using separate logistic regressions.

RESULTS

In individual models, the strongest sleep-wake correlates of low cognitive performance were measures of weaker and unstable 24-hour rhythms; greater 24-hour fragmentation; longer time-in-bed; and lower rhythm amplitude. One standard deviation worse on these sleep-wake factors was associated with ∼20%-30% greater odds of having low cognitive performance. In an internally cross-validated prediction model, the independent correlates of low cognitive performance were: lower Sleep Regularity Index scores; lower pseudo-F statistics (modellability of 24-hour rhythms); lower activity rhythm amplitude; and greater time in bed. Area under the curve was low/moderate (64%) indicating poor predictive utility.

CONCLUSION

The strongest sleep-wake behavioral correlates of low cognitive performance were measures of longer time-in-bed and irregular/weak rhythms. These sleep-wake assessments were not useful to identify previous low cognitive performance. Given their potential modifiability, experimental trials could test if targeting midlife time-in-bed and/or irregular rhythms influences cognition.

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.

Different Types of Cell Death in Diabetic Neuropathy: A Focus on Mechanisms and Therapeutic Strategies

Diabetic neuropathy (DN) is a common complication of diabetes, affecting over 50% of patients, leading to significant pain and a burden. Currently, there are no effective treatments available. Cell death is considered a key factor in promoting the progression of DN. This article reviews how cell death is initiated in DN, emphasizing the critical roles of oxidative stress, mitochondrial dysfunction, inflammation, endoplasmic reticulum stress, and autophagy. Additionally, we thoroughly summarize the mechanisms of cell death that may be involved in the pathogenesis of DN, including apoptosis, autophagy, pyroptosis, and ferroptosis, among others, as well as potential therapeutic targets offered by these death mechanisms. This provides potential pathways for the prevention and treatment of diabetic neuropathy in the future.

Cognitive impairment and associated factors among patients with diabetes mellitus in Africa: a systematic review and meta-analysis

Background

Inappropriate management of blood sugar in patients with diabetes mellitus leads to micro-vascular and macro-vascular complications, subsequently leading to high morbidity and mortality rates. In addition, diabetes independently increases the occurrence of cognitive impairment complicated by dementia. Scientific evidence on the magnitude of cognitive impairment will provide a sound basis for the determination of healthcare needs and the planning of effective healthcare services. Despite this, there are no comprehensive data on the prevalence and associated factors of cognitive impairment among patients with diabetes in Africa.

Methods

To identify relevant articles for this review, we searched PubMed, Cochrane Library, Science Direct, African Journals Online, and Google Scholar. After extraction, the data were imported into Stata software version 11 (Stata Corp., TX, USA) for further analysis. The random-effects model, specifically the DerSimonian and Laird (D+L) pooled estimation method, was used due to the high heterogeneity between the included articles. Begg's and Egger's regression tests were used to determine the evidence of publication bias. Sub-group analyses and sensitivity analyses were also conducted to handle heterogeneity.

Results

The pooled prevalence of cognitive impairment among patients with diabetes in Africa is found to be 43.99% (95% CI: 30.15-57.83, p < 0.001). According to our analysis, primary level of education [pooled odds ratio (POR) = 6.08, 95% CI: 3.57-10.36, I 2 = 40.7%], poorly controlled diabetes mellitus (POR = 5.85, 95% CI: 1.64-20.92, I 2 = 87.8%), age above 60 years old (POR = 3.83, 95% 95% CI: 1.36-10.79, I 2 = 63.7%), and diabetes duration greater than 10 years (POR = 1.13; 95% CI: 1.07-1.19, I 2 = 0.0%) were factors associated with cognitive impairment among patients with diabetes.

Conclusion

Based on our systematic review, individuals with diabetes mellitus exhibit a substantial prevalence rate (43.99%) of cognitive impairment. Cognitive impairment was found to be associated with factors such as primary level of education, poorly controlled diabetes mellitus, age above 60 years, and diabetes duration greater than 10 years. Developing suitable risk assessment tools is crucial to address uncontrolled hyperglycemia effectively.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42024561484.

Protective effects of treadmill exercise on apoptotic neuronal damage and astrocyte activation in ovariectomized and/or diabetic rat prefrontal cortex: molecular and histological aspects

OBJECTIVE

Both estrogen deprivation and diabetes mellitus are known as risk factors for neuronal damage. Using an animal model of ovariectomized and/or streptozotocin (STZ)-induced diabetes mellitus, we examined expression of apoptosis-related proteins, neuronal damage, and astrocyte activation in prefrontal cortex of rats with/without treadmill exercise.

METHODS

Adult female Wistar rats were divided into control, ovariectomized (Ovx, bilateral ovariectomy), diabetic (Dia, STZ 60 mg/kg; i.p.), and ovariectomized diabetic (Ovx + Dia) groups. Next, animals in each group were randomly subdivided into non-exercise and exercise subgroups. Animals in the exercise groups underwent moderate treadmill running for 4 weeks (5 days/week). Thereafter, expression of Bax, Bcl-2, and caspase-3, as apoptosis-related proteins, number of neurons, and number of glial fibrillary acidic protein (GFAP)-positive cells in prefrontal cortex were measured using immunoblotting, cresyl violet staining, and immunohistochemistry, respectively.

RESULTS

In both Dia and Ovx + Dia groups, Bax and caspase-3 protein levels and number of GFAP-positive cells were higher than those in the control group, while Bcl-2 protein level and number of neurons compared were lower than the control group. Beneficial effects of exercise to prevent apoptosis-mediated neuronal damage and astrocyte activation were also observed in the Dia group.

CONCLUSION

Based on our results, physical exercise could be beneficial to attenuate diabetes-induced neuronal damage in the prefrontal cortex via inhibition of apoptosis.

Sex Differences in the Trajectories of Cognitive Decline and Affected Cognitive Domains Among Older Adults With Controlled and Uncontrolled Glycemia

BACKGROUND

We aimed to analyze the trajectories of cognitive decline as a function of the presence of type 2 diabetes and glycemic control in analyzes stratified by sex in an 8-year follow-up period.

METHODS

A total of 1 752 men and 2 232 women aged ≥50 years who participated in the English Longitudinal Study of Ageing (ELSA), conducted from 2004 to 2012, were analyzed. The outcomes of interest were performance on the cognitive domains of memory, executive function, and temporal orientation as well as the global cognition score. Cognitive performance was standardized in z-scores in strata based on schooling and age. The participants were classified as without diabetes, with controlled glycemia, and with uncontrolled glycemia, according to medical diagnosis, glucose-lowering medications use and HbA1c levels. Generalized linear mixed models controlled by sociodemographic, behavioral, and health-related characteristics were used for the trajectory analyses.

RESULTS

No differences in z-scores were found for global cognition or cognitive domains based on diabetes classification in men and women at baseline. More than 8 years of follow up, women with uncontrolled glycemia had a greater decline in z-scores for global cognition (-0.037 SD/year [95% CI: -0.073; -0.001]) and executive function (-0.049 SD/year [95% CI: -0.092; -0.007]) compared with those without diabetes. No significant difference in trajectories of global cognition or any cognitive domain was found in men as a function of diabetes classification.

CONCLUSIONS

Women with uncontrolled glycemia are at greater risk of a decline in global cognition and executive function than those without diabetes.

Effects of prediabetes and type 2 diabetes on cognitive functions

INTRODUCTION

We aimed to investigate the effect of glycemic impairment in prediabetes on cognitive impairment and the impact of glycemic control on cognitive function in patients with diabetes.

MATERIALS AND METHODS

This age- and sex-matched case-control study included a total of 80 individuals: 20 patients with prediabetes, 20 patients with well-controlled type 2 diabetes mellitus (T2DM) (HbA1C < %7.5), 20 patients with poorly controlled T2DM (HbA1C >% 7.5), and 20 healthy controls.

RESULTS

The poorly controlled T2DM patients performed significantly worse than controls and patients with prediabetes in the verbal memory process test (p = 0.041). In Trail Making Test B, the well-controlled and poorly-controlled groups with diabetes performed significantly worse (p = 0.015) than patients with prediabetes and controls, and in the Wisconsin Card Sorting Test (WCST), all three patient groups performed significantly worse (p = 0.007) than controls.

CONCLUSION

T2DM causes early brain aging and declines cognitive functions since the prediabetic stage. Poor glycemic control in T2DM patients contributes to cognitive impairments, especially in learning.

Are Hyperglycemia-Induced Changes in the Retina Associated with Diabetes-Correlated Changes in the Brain? A Review from Zebrafish and Rodent Type 2 Diabetes Models

Diabetes is prevalent worldwide, with >90% of the cases identified as Type 2 diabetes. High blood sugar (hyperglycemia) is the hallmark symptom of diabetes, with prolonged and uncontrolled levels contributing to subsequent complications. Animal models have been used to study these complications, which include retinopathy, nephropathy, and peripheral neuropathy. More recent studies have focused on cognitive behaviors due to the increased risk of dementia/cognitive deficits that are reported to occur in older Type 2 diabetic patients. In this review, we collate the data reported from specific animal models (i.e., mouse, rat, zebrafish) that have been examined for changes in both retina/vision (retinopathy) and brain/cognition, including db/db mice, Goto-Kakizaki rats, Zucker Diabetic Fatty rats, high-fat diet-fed rodents and zebrafish, and hyperglycemic zebrafish induced by glucose immersion. These models were selected because rodents are widely recognized as established models for studying diabetic complications, while zebrafish represent a newer model in this field. Our goal is to (1) summarize the published findings relevant to these models, (2) identify similarities in cellular mechanisms underlying the disease progression that occur in both tissues, and (3) address the hypothesis that hyperglycemic-induced changes in retina precede or predict later complications in brain.

A systematic review of the impact of type 2 diabetes on brain cortical thickness

Introduction

Type 2 diabetes (T2D) has been linked to cognitive impairment and dementia, but its impact on brain cortical structures in individuals prior to or without cognitive impairment remains unclear.

Methods

We conducted a systematic review of 2,331 entries investigating cerebral cortical thickness changes in T2D individuals without cognitive impairment, 55 of which met our inclusion criteria.

Results

Most studies (45/55) reported cortical brain atrophy and reduced thickness in the anterior cingulate, temporal, and frontal lobes between T2D and otherwise cognitively healthy controls. However, the balance of studies (10/55) reported no significant differences in either cortical or total brain volumes. A few reports also noticed changes in the occipital cortex and its gyri. As part of the reports, less than half of studies (18/55) described a correlation between T2D and hippocampal atrophy. Variability in sample characteristics, imaging methods, and software could affect findings on T2D and cortical atrophy.

Discussion

In conclusion, T2D appears linked to reduced cortical thickness, possibly impacting cognition and dementia risk. Microvascular disease and inflammation in T2D may also contribute to this risk. Further research is needed to understand the underlying mechanisms and brain health implications.