Development of Dementia in Type 2 Diabetes Patients: Mechanisms of Insulin Resistance and Antidiabetic Drug Development

Association Between Triglyceride Glucose Index with Cognitive Impairment and Dementia in Adult Population: A Meta-Analysis

The current understanding of the correlation between insulin resistance (IR) and cognitive dysfunction is limited. Therefore, the objective of this systematic review and meta-analysis was to assess the association between the triglyceride glucose (TyG) index, a recently suggested indicator of IR, and cognitive impairment and dementia in the adult population. Observational studies pertinent to our research were identified through comprehensive searches of the PubMed, Embase, and Web of Science databases. To account for potential heterogeneity, the random-effects models were employed to aggregate the findings. This meta-analysis included ten observational studies involving 5602409 participants. Compared to those with the low TyG index, subjects with the high TyG index were significantly associated with the risk of cognitive impairment [risk ratio (RR): 1.39, 95% confidence interval (CI): 1.22 to 1.59, p<0.001; I2=45%) and dementia (RR: 1.30, 95% CI: 1.06 to 1.60, p=0.01; I2=50%). The association was consistent for Alzheimer's disease (RR: 1.35, 95% CI: 1.04 to 1.76, p=0.03; I2=54%) and vascular dementia (RR: 1.18, 95% CI: 1.13 to 1.24, p<0.001; I2=0%). Subgroup analyses showed that the association between TyG index with cognitive impairment and dementia were stronger in cross-sectional studies than that in cohort studies (p for subgroup difference=0.02), but not significantly modified by age, sex, or diabetic status of the participants. In conclusion, a high TyG index may be associated with higher risk of cognitive impartment and dementia in adult population.

Peripheral helper T cells in human diseases

Peripheral helper T cells (Tph) are a specialized subset of CD4+ T cells with the ability to help B cells and induce antibody production. Although usually located in ectopic lymphoid-like structures (ELS), inside the peripheral blood, Tph cells can also be identified. The aberrant proliferation and functions of Tph cells are commonly found in the patients with disease. In this review, first we will summarize the biological characteristics of Tph cells, such as the expression of surface molecules, transcription factors and cytokines, and discuss its B cell help functions. Tph cells also have roles in a wide range of human diseases, including autoimmune diseases, infectious diseases, malignancies etc. Therefore, there is a strong interest in targeting Tph cells to improve treat strategies of human diseases.

A Comprehensive Review of Membrane Transporters and MicroRNA Regulation in Alzheimer's Disease

Alzheimer's disease (AD) is a distressing neurodegenerative condition characterized by the accumulation of amyloid-beta (Aβ) plaques and tau tangles within the brain. The interconnectedness between membrane transporters (SLCs) and microRNAs (miRNAs) in AD pathogenesis has gained increasing attention. This review explores the localization, substrates, and functions of SLC transporters in the brain, emphasizing the roles of transporters for glutamate, glucose, nucleosides, and other essential compounds. The examination delves into the significance of SLCs in AD, their potential for drug development, and the intricate realm of miRNAs, encompassing their transcription, processing, functions, and regulation. MiRNAs have emerged as significant players in AD, including those associated with mitochondria and synapses. Furthermore, this review discusses the intriguing nexus of miRNAs targeting SLC transporters and their potential as therapeutic targets in AD. Finally, the review underscores the interaction between SLC transporters and miRNA regulation within the context of Alzheimer's disease, underscoring the need for further research in this area. This comprehensive review aims to shed light on the complex mechanisms underlying the causation of AD and provides insights into potential therapeutic approaches.

Association Between Antidiabetic Drugs and Delirium: A Study Based on the Adverse Drug Event Reporting Database in Japan

BACKGROUND AND OBJECTIVE

Several associations between diabetes mellitus and delirium have been reported; however, they have been inconsistent, and evidence on the effects of antidiabetic medications on delirium is also limited. This study aimed to investigate whether the use of antidiabetic drugs is a risk factor for delirium development.

METHODS

Using the Japanese Adverse Event Reporting Database, we analyzed 662,899 reports between 2004 and 2022. Reporting odds ratios (RORs) and 95% confidence intervals (CIs) for delirium associated with diabetes and using each antidiabetic medication were calculated after adjusting for potential confounders.

RESULTS

Overall, 8892 of the reports analyzed were associated with delirium. A comparison of the incidence of delirium between patients with and without diabetes showed no significant difference, with 1.34% in patients without diabetes and 1.37% in those with diabetes. In each antidiabetic medication, signals for delirium were detected for sulfonylurea (crude ROR, 1.35; 95% CI 1.21-1.51) and insulin (crude ROR, 1.28; 95% CI 1.13-1.44). These results were maintained even after adjusting for factors with potential confounders (sulfonylurea: adjusted ROR, 1.75; 95% CI 1.54-2.00, insulin: adjusted ROR, 1.35; 95% CI 1.20-1.54).

CONCLUSIONS

Our results suggest no association between diabetes and delirium; however, using sulfonylurea and insulin may be associated with delirium development. Nonetheless, these findings should be validated in future studies.

Protective effects of GuanXinNing tablet (GXNT) on diabetic encephalopathy in zucker diabetic obesity (ZDF) rats

BACKGROUND

Diabetic encephalopathy (DE) is a complication of diabetes that leads to cognitive and behavioral decline. Utilizing safe and effective complementary and alternative medications for its management is a wise choice. Previous studies have shown that GuanXinNing Tablet (GXNT), an oral preparation primarily derived from two Chinese herbs, Salvia miltiorrhiza Bge. and Ligusticum chuanxiong Hort., exerts a beneficial neuroprotective effect. In this study, we explored the protective effects of GXNT on DE in male Zucker diabetic fatty (ZDF) rats induced by a high-fat diet, aiming to ascertain its significance and potential mechanisms.

METHODS

ZDF rats were induced to develop type 2 diabetes (T2DM) with DE by a high-fat diet and treated with GXNT for 8 weeks until they were 20 weeks old. Throughout the experiment, the animals' vital parameters, such as body weight, were continuously monitored. Cognitive function was evaluated using the Y maze test. Biochemical kits were employed to analyze blood glucose, lipids, and vascular endothelial-related factors. Cerebrovascular lesions were assessed using magnetic resonance angiography (MRA) imaging. Brain lesions were evaluated using hematoxylin and eosin (H&E) staining and ultrastructure observation. IgG and albumin (ALB) leakage were detected using immunofluorescence.

RESULTS

GXNT demonstrated an enhancement in the overall well-being of the animals. It notably improved cognitive and behavioral abilities, as demonstrated by extended retention time in the novel heterogeneous arm during the Y-maze test. GXNT effectively regulated glucose and lipid metabolism, reducing fasting and postprandial blood glucose, glycated hemoglobin (HbA1c), and total cholesterol (TC) levels. Additionally, it exhibited a protective effect on the vascular endothelium by reducing the serum TXB2/PGI2 ratio while elevating NO and PGI2 levels. Moreover, GXNT ameliorated stenosis and occlusion in cerebral vessel branches, increased the number of microvessels and neurons around the hippocampus, and improved microvascular occlusion in the cerebral cortex, along with addressing perivascular cell abnormalities. Immunofluorescence staining showed a decrease in the fluorescence intensity of IgG and ALB in the cerebral cortex.

CONCLUSIONS

GXNT demonstrated a highly satisfactory protective effect on DE in ZDF rats. Its mechanism of action could be based on the regulation of glucolipid metabolism and its protective effect on the vascular endothelium.

[Lifetide biofeedback intervention in type 2 diabetic patients: a pilot observation]

OBJECTIVE

To evaluate the therapeutic efficacy of lifetide biofeedback intervention in patients with type 2 diabetes mellitus (T2DM).

METHODS

We analyzed the changes in average blood glucose, estimated glycosylated hemoglobin (HbA1c), fasting blood glucose and HbA1c levels in 5 patients with T2DM undergoing lifetide biofeedback intervention without the use of hypoglycemic drugs. A transient blood glucose monitoring system was used for drug withdrawal management during the intervention.

RESULTS

Compared with those before the intervention, the average blood glucose and fasting blood glucose and HbA1c levels showed no significant changes after the intervention without using hypoglycemic drugs (P>0.05), but the estimated HbA1c was significantly decreased after the intervention (P<0.05). Two patients achieved complete remission, two showed partial remission, and one had substantially improved blood glucose levels. One patient showed a marked increase in extremity temperature after the intervention (P<0.05). Another patient had a significantly increased heart rate variability index (P<0.05) without obvious changes in heart rate after the intervention (P>0.05).

CONCLUSION

By reestablishing the balance in autonomic nervous system regulation and enhancing peripheral microcirculation, lifetide biofeedback intervention helps to maintain stable blood glucose levels, achieve disease remission, and reduce the occurrence of complications in T2DM patients after discontinuation of hypoglycemic drugs without changing their lifestyles.

Amygdala activity and amygdala-hippocampus connectivity: Metabolic diseases, dementia, and neuropsychiatric issues

With rapid aging of the population worldwide, the number of people with dementia is dramatically increasing. Some studies have emphasized that metabolic syndrome, which includes obesity and diabetes, leads to increased risks of dementia and cognitive decline. Factors such as insulin resistance, hyperglycemia, high blood pressure, dyslipidemia, and central obesity in metabolic syndrome are associated with synaptic failure, neuroinflammation, and imbalanced neurotransmitter levels, leading to the progression of dementia. Due to the positive correlation between diabetes and dementia, some studies have called it "type 3 diabetes". Recently, the number of patients with cognitive decline due to metabolic imbalances has considerably increased. In addition, recent studies have reported that neuropsychiatric issues such as anxiety, depressive behavior, and impaired attention are common factors in patients with metabolic disease and those with dementia. In the central nervous system (CNS), the amygdala is a central region that regulates emotional memory, mood disorders, anxiety, attention, and cognitive function. The connectivity of the amygdala with other brain regions, such as the hippocampus, and the activity of the amygdala contribute to diverse neuropathological and neuropsychiatric issues. Thus, this review summarizes the significant consequences of the critical roles of amygdala connectivity in both metabolic syndromes and dementia. Further studies on amygdala function in metabolic imbalance-related dementia are needed to treat neuropsychiatric problems in patients with this type of dementia.