Interactive relationships of Type 2 diabetes and bipolar disorder with cognition: evidence of putative premature cognitive ageing in the UK Biobank Cohort

Neurocognitive correlates of metabolic dysregulation in individuals with mood disorders: a systematic review and meta-analysis

Individuals with mood disorders are predisposed to metabolic dysfunction, while those with metabolic dysregulation such as diabetes and obesity experience more severe depressive symptoms. Both metabolic dysfunction and mood disorders are independently associated with cognitive deficits. Therefore, given their close association, this study aimed to explore the association between metabolic dysfunction in individuals with mood disorders in relation to cognitive outcomes. A comprehensive search comprised of these three domains was carried out; a random-effects meta-analysis pooling mean cognitive outcomes was conducted (PROSPERO ID: CRD42022295765). Sixty-three studies were included in this review; 26 were synthesized in a quantitative meta-analysis. Comorbid metabolic dysregulation was associated with significantly lower global cognition among individuals with mood disorders. These trends were significant within each mood disorder subgroup, including major depressive disorder, bipolar disorder, and self-report depression/depressive symptoms. Type 2 diabetes was associated with the lowest cognitive performance in individuals with mood disorders, followed by peripheral insulin resistance, body mass index ⩾25 kg/m2, and metabolic syndrome. Significant reduction in scores was also observed among individual cognitive domains (in descending order) of working memory, attention, executive function, processing speed, verbal memory, and visual memory. These findings demonstrate the detrimental effects of comorbid metabolic dysfunction in individuals with mood disorders. Further research is required to understand the underlying mechanisms connecting mood disorders, metabolism, and cognition.

Relative associations of behavioral and physiological risks for cardiometabolic disease with cognition in bipolar disorder during mid and later-life: findings from the UK biobank

BACKGROUND

Cardiometabolic disease risk factors are disproportionately prevalent in bipolar disorder (BD) and are associated with cognitive impairment. It is, however, unknown which health risk factors for cardiometabolic disease are relevant to cognition in BD. This study aimed to identify the cardiometabolic disease risk factors that are the most important correlates of cognitive impairment in BD; and to examine whether the nature of the relationships vary between mid and later life.

METHODS

Data from the UK Biobank were available for 966 participants with BD, aged between 40 and 69 years. Individual cardiometabolic disease risk factors were initially regressed onto a global cognition score in separate models for the following risk factor domains; (1) health risk behaviors (physical activity, sedentary behavior, smoking, and sleep) and (2) physiological risk factors, stratified into (2a) anthropometric and clinical risk (handgrip strength, body composition, and blood pressure), and (2b) cardiometabolic disease risk biomarkers (CRP, lipid profile, and HbA1c). A final combined multivariate regression model for global cognition was then fitted, including only the predictor variables that were significantly associated with cognition in the previous models.

RESULTS

In the final combined model, lower mentally active and higher passive sedentary behavior, higher levels of physical activity, inadequate sleep duration, higher systolic and lower diastolic blood pressure, and lower handgrip strength were associated with worse global cognition.

CONCLUSIONS

Health risk behaviors, as well as blood pressure and muscular strength, are associated with cognitive function in BD, whereas other traditional physiological cardiometabolic disease risk factors are not.

Evaluation of the biological efficiency of Terminalia chebula fruit extract against neurochemical changes induced in brain of diabetic rats: an epigenetic study

Diabetes mellitus (DM) is a chronic and progressive metabolic disorder that can stimulate neuroinflammation and increase oxidative stress in the brain. Therefore, the present study was aimed to assess the efficacy of ethanolic Terminalia chebula extract against the neurochemical and histopathological changes induced in the brains of diabetic rats. The study clarified the reduction in oxidative stress induced in the brains of diabetic rats by the significant (P ≤ 0.05) increase in levels of the antioxidants with decreasing the peroxidation products via ethanolic T. chebula extract at both doses (400 and 600 mg/kg). Moreover, T. chebula extract improved the brain integrity by lowering levels of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), β-amyloid (Aβ) content, monocyte chemoattractant protein-1 (MCP-1) and acetylcholine esterase (ACHE) significantly (P ≤ 0.05) in a dose dependent manner compared to brain of diabetic rats. Severe nuclear pyknosis and degeneration were noticed in neurons of the cerebral cortex, hippocampus and striatum in brains of diabetic rats. The severity of these alterations decreased with T. chebula extract at a dose of 600 mg/kg compared to the other treated groups. The different electrophoretic protein and isoenzyme assays revealed that the lowest similarity index (SI%) values exist in the brains of diabetic rats compared to the control group. The quantity of the most native proteins and isoenzyme types increased significantly (P ≤ 0.05) in the brains of diabetic rats, and these electrophoretic variations were completely diminished by T. chebula extract. The study concluded that T. chebula extract ameliorated the biochemical, histopathological and electrophoretic abnormalities induced in the brains of diabetic rats when administered at a dose of 600 mg/kg.

Investigation of Pancreatic-beta Cells Role in the Biological Process of Ageing

BACKGROUND

Cellular senescence is associated with the formation and progression of a range of illnesses, including ageing and metabolic disorders such as diabetes mellitus and pancreatic beta cell dysfunction. Ageing and reduced glucose tolerance are interconnected. Often, Diabetes is becoming more common, which is concerning since it raises the risk of a variety of age-dependent disorders such as cardiovascular disease, cancer, Parkinson's disease, stroke, and Alzheimer's disease.

OBJECTIVES

The objectives of this study are to find out the most recent research on how ageing affects the functions of pancreatic beta cells, beta cell mass, beta cell senescence, mitochondrial dysfunction, and hormonal imbalance.

METHODS

Various research and review manuscripts are gathered from various records such as Google Scholar, PubMed, Mendeley, Scopus, Science Open, the Directory of Open Access Journals, and the Education Resources Information Centre, using different terms like "Diabetes, cellular senescence, beta cells, ageing, insulin, glucose".

RESULTS

In this review, we research novel targets in order to discover new strategies to treat diabetes. Abnormal glucose homeostasis and type 2 diabetes mellitus in the elderly may aid in the development of novel medicines to delay or prevent diabetes onset, improve quality of life, and, finally, increase life duration.

CONCLUSION

Aging accelerates beta cell senescence by generating premature cell senescence, which is mostly mediated by high glucose levels. Despite higher plasma glucose levels, hepatic gluconeogenesis accelerates and adipose tissue lipolysis rises, resulting in an increase in free fatty acid levels in the blood and worsening insulin resistance throughout the body.

An update on potential pharmacotherapies for cognitive impairment in bipolar disorder

INTRODUCTION

Cognitive impairment is a core feature of bipolar disorder (BD) that impedes recovery by preventing the return to optimal socio-occupational functioning and reducing quality of life. Presently, there are no efficacious treatments for cognitive impairment in BD, but many pharmacological interventions are being considered as they have the potential to target the underlying pathophysiology of the disorder.

AREAS COVERED

This review summarizes the available evidence for pharmacological interventions for cognitive impairment in bipolar disorder. We searched PubMed, MedLine, and PsycInfo from inception to December 1^st, 2022. Traditional treatments, such as lithium, anticonvulsants (lamotrigine), antipsychotics (aripiprazole, asenapine, cariprazine, lurasidone, and olanzapine), antidepressants (vortioxetine, fluoxetine, and tianeptine) and psychostimulants (modafinil), and emerging interventions, such as acetylcholinesterase inhibitors (galantamine and donepezil), dopamine agonists (pramipexole), erythropoietin, glucocorticoid receptor antagonists (mifepristone), immune modulators (infliximab, minocycline and doxycycline), ketamine, metabolic agents (insulin, metformin, and liraglutide), probiotic supplements, and Withania somnifera are discussed.

EXPERT OPINION

The investigation of interventions for cognitive impairment in BD is a relatively under-researched area. In the past, methodological pitfalls in BD cognition trials have also been a critical limiting factor. Expanding on the existing literature and identifying novel pharmacological and non-pharmacological treatments for cognitive impairment in BD should be a priority.

A preliminary investigation of the clinical and cognitive correlates of circulating vitamin D in bipolar disorder

The role that vitamin D plays in the cognitive and clinical characteristics of bipolar disorder (BD) is unclear. We examined differences in the levels and deficiency status of vitamin D in an Australian sample of BD patients compared to healthy controls; and determined the extent to which vitamin D is associated with clinical variables and cognitive function in the sample. 22 healthy controls and 55 stable outpatients with a diagnosis of BD and low-grade mood symptomatology provided a sample of blood and completed cognitive tests and clinical measures. Plasma concentrations of 25-hydroxyvitamin D (vitamin D) were assayed and used to segregate participants into subgroups with sufficient or deficient levels of vitamin D. Subgroups were then compared in terms of global cognition and a range of sociodemographic and clinical factors (number of past mood episodes, illness duration, seasonal mood pattern, mood symptom severity), while mean levels of vitamin D were compared between patients and controls. Although almost 27% of the current sample were vitamin D deficient, no significant differences in mean vitamin D levels or the prevalence of vitamin D deficiency were evident between BD patients and controls. Vitamin D was not associated with global cognition in either patients or controls, nor any of the clinical measures assessed in the study. In conclusion, we observed no difference in the vitamin D levels and deficiency status of an Australian sample of healthy individuals and BD patients with low grade mood symptomatology compared to controls. Clinical symptoms and global cognition also appear to be independent of vitamin D levels in BD.