Obesity and neuroinflammation: a pathway to cognitive impairment

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.

Role of metabolic dysfunction and inflammation along the liver-brain axis in animal models with obesity-induced neurodegeneration

The interaction between metabolic dysfunction and inflammation is central to the development of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Obesity-related conditions like type 2 diabetes and non-alcoholic fatty liver disease exacerbate this relationship. Peripheral lipid accumulation, particularly in the liver, initiates a cascade of inflammatory processes that extend to the brain, influencing critical metabolic regulatory regions. Ceramide and palmitate, key lipid components, along with lipid transporters lipocalin-2 and apolipoprotein E, contribute to neuroinflammation by disrupting blood-brain barrier integrity and promoting gliosis. Peripheral insulin resistance further exacerbates brain insulin resistance and neuroinflammation. Preclinical interventions targeting peripheral lipid metabolism and insulin signaling pathways have shown promise in reducing neuroinflammation in animal models. However, translating these findings to clinical practice requires further investigation into human subjects. In conclusion, metabolic dysfunction, peripheral inflammation, and insulin resistance are integral to neuroinflammation and neurodegeneration. Understanding these complex mechanisms holds potential for identifying novel therapeutic targets and improving outcomes for neurodegenerative diseases.

Intranasal delivery of extracellular vesicles: A promising new approach for treating neurological and respiratory disorders

BACKGROUND

Extracellular vesicles (EVs) are membrane vesicles secreted by all types of cells, including bacteria, animals, and plants. These vesicles contain proteins, nucleic acids, and lipids from their parent cells and can transfer these components between cells. EVs have attracted attention for their potential use in diagnosis and therapy due to their natural properties, such as low immunogenicity, high biocompatibility, and ability to cross the blood-brain barrier. They can also be engineered to carry therapeutic molecules. EVs can be delivered via various routes. The intranasal route is particularly advantageous for delivering them to the central nervous system, making it a promising approach for treating neurological disorders.

SCOPE OF REVIEW

This review delves into the promising potential of intranasally administered EVs-based therapies for various medical conditions, with a particular focus on those affecting the brain and central nervous system. Additionally, the potential use of these therapies for pulmonary conditions, cancer, and allergies is examined, offering a hopeful outlook for the future of medical treatments.

MAJOR CONCLUSIONS

The intranasal administration of EVs offers significant advantages over other delivery methods. By directly delivering EVs to the brain, specifically targeting areas that have been injured, this administration proves to be highly efficient and effective, providing reassurance about the progress in medical treatments. Intranasal delivery is not limited to brain-related conditions. It can also benefit other organs like the lungs and stimulate a mucosal immune response against various pathogens due to the highly vascularized nature of the nasal cavity and airways. Moreover, it has the added benefit of minimizing toxicity to non-targeted organs and allows the EVs to remain longer in the body. As a result, there is a growing emphasis on conducting clinical trials for intranasal administration of EVs, particularly in treating respiratory tract pathologies such as coronavirus disease.

A high fat, high sugar diet exacerbates persistent post-surgical pain and modifies the brain-microbiota-gut axis in adolescent rats

Persistent post-surgical pain (PPSP) occurs in a proportion of patients following surgical interventions. Research suggests that specific microbiome components are important for brain development and function, with recent studies demonstrating that chronic pain results in changes to the microbiome. Consumption of a high fat, high sugar (HFHS) diet can drastically alter composition of the microbiome and is a modifiable risk factor for many neuroinflammatory conditions. Therefore, we investigated how daily consumption of a HFHS diet modified the development of PPSP, brain structure and function, and the microbiome. In addition, we identified significant correlations between the microbiome and brain in animals with PPSP. Male and female rats were maintained on a control or HFHS diet. Animals were further allocated to a sham or surgery on postnatal day (p) p35. The von Frey task measured mechanical nociceptive sensitivity at a chronic timepoint (p65-67). Between p68-72 rats underwent in-vivo MRI to examine brain volume and diffusivity. At p73 fecal samples were used for downstream 16 s rRNA sequencing. Spearman correlation analyses were performed between individual microbial abundance and MRI diffusivity to determine if specific bacterial species were associated with PPSP-induced brain changes. We found that consumption of a HFHS diet exacerbated PPSP in adolescents. The HFHS diet reduced overall brain volume and increased white and grey matter density. The HFHS diet interacted with the surgical intervention to modify diffusivity in numerous brain regions which were associated with specific changes to the microbiome. These findings demonstrate that premorbid characteristics can influence the development of PPSP and advance our understanding of the contribution that the microbiome has on function of the brain-microbiota-gut axis.

Adiposity and domain-specific stroke recovery: A Mendelian randomization study

INTRODUCTION

While adiposity is an established risk factor for incident ischemic stroke, its influence on functional recovery after stroke is uncertain. We leveraged Mendelian randomization (MR) to examine the causal effects of body mass index (BMI) and waist-to-hip ratio (WHR) on post-stroke motor, cognitive, and global recovery.

MATERIALS AND METHODS

Genetic proxies for BMI and WHR were obtained from a genome-wide association study (GWAS) meta-analysis of the GIANT consortium and the UK Biobank (n = 806,834). The primary outcomes were longitudinal trajectories of three National Institutes of Health Stroke Scale (NIHSS) measures assessed over a 2-year period: motor function subscores, cognitive performance subscores, and total NIHSS scores (as a measure of global recovery). Genetic associations with these stroke recovery outcomes were obtained from a GWAS conducted within the VISP trial of mild ischemic stroke (n = 1270). MR effects were estimated using the inverse-variance weighted method.

RESULTS

A 1-standard deviation (SD) increase (~4.8 kg/m2) in genetically predicted BMI associated with lower odds of post-stroke motor improvement (OR = 0.37, 95% CI = 0.19-0.72; p = 0.003). Similarly, a genetically predicted increase in BMI was associated with worse cognitive (β = -0.12, 95% CI = -0.21, -0.03; p = 0.009) and global recovery (β = -0.36, 95% CI = -0.59, -0.13; p = 0.002). Associations between genetically predicted WHR and post-stroke recovery were directionally concordant but were not statistically significant (p > 0.05).

DISCUSSIONS AND CONCLUSIONS

Human genetic evidence suggests that elevated adiposity negatively impacts multiple post-stroke outcomes, including motor function, cognition, and overall recovery. The biological pathways underlying these associations warrant further investigation.

Role of obesity-related anthropometric indicators on cognitive function in obese older adults: A systematic review and meta-analysis

OBJECTIVES

The association between obesity and cognitive function in older adults remains inconsistent due to the use of various anthropometric indicators, such as body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR). More conclusive evidence is warranted. The aim of this study was to systematically summarize and synthesize the association between specific obesity-related anthropometric indicators (BMI, WC, and WHR) and cognitive function in obese older adults. Higher BMI, WC, or WHR is linked to cognitive decline in this population.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A comprehensive literature search was carried out using PubMed, CINAHL, Scopus, Embase, and the Cochrane Library (from their inception to October 2023). Studies investigating the association between obesity indicators, including BMI, WC, WHR, and cognitive performance in older adults were included. The weighted mean difference (WMD), Odds Ratio, and 95 % confidence interval (CI) were used to estimate the pooled effect size. A random-effects model was employed as the main method. Subgroup analyses and the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach were assessed (registered number: CRD42023461770).

RESULTS

Thirty-three eligible studies, involving 83,251 participants, were included. Obese older adults, as assessed by WC, had lower Mini-Mental State Examination (MMSE) scores than non-obese counterparts (WMD -0.84, 95 % CI -1.64 to -0.05, very low certainty). Those measured by WHR had a 31 % higher risk of cognitive impairment (OR 1.31, 95 % CI 1.12 to 1.53, moderate certainty). Subgroup analysis revealed a lower Montreal Cognitive Assessment (MoCA) score in obese group classified by WHO criteria compared to controls (WMD -1.67, 95 % CI -2.94 to -0.39).

CONCLUSION

This review suggests an association between obesity, as measured by WHR and WC, and poorer cognitive performance in older adults. WHR is moderately recommended for identifying cognitive impairment-related obesity, while WC recommendations are limited by very low evidence certainty.

Causal links between obesity, lipids, adipokines, and cognition: a bidirectional Mendelian-randomization analysis

Background

The aim of this study was to explore the genetic level association between obesity, lipids, adipokines, and cognitive ability using bidirectional Mendelian randomization (MR) strategies.

Methods

Summary data for three obesity indicators [body mass index (BMI), body fat percentage (BFP) and waist-hip ratio (WHR)], three lipid indicators [HDL cholesterol (HDL), LDL cholesterol (LDL) and triglycerides (TG)], three adipokines [circulating leptin (LEP), Agouti-related protein (AgRP) and Adiponectin (APDN)], and four cognitive ability indicators [cognitive function (CF), cognitive performance (CP), simple reaction time (SRT) and fluid intelligence score (FIS)] were collected. Bidirectional inverse-variance weighted Mendelian randomization (MR) was employed to evaluate the relationship between adiposity and cognitive function. We employed genetic instruments for adiposity indicators as exposures in one direction, and repeated the analysis in the opposite direction using instruments for cognitive function. Sensitivity analyses were conducted to explore heterogeneity and potential horizontal pleiotropy.

Results

Genetically predicted adiposity showed robust associations with markers of cognitive ability. Higher genetically predicted obesity indicators (such as BMI, BFP and WHR), and lipid and adipokineslevels (such as HDL and AgRP) with reduced cognitive ability indicators (such as CF and CP). In the opposite direction, FIS and SRT may influence BMI and HDL respectively. MR estimates for the effects of cognition ability on all obesity, lipids and adipokines measures indicated worse FIS and SRT were associated with higher BMI and lower HDL.

Conclusions

Our MR reveals that high BMI, BFP, WHR and AgRP have negative causal direct effects with cognitive ability, while high HDL and ADPN have positive causal direct effects with cognitive ability. For the reverse causal direction, our consistent findings that worse cognitive function such as SRT and FIS may influence serum HDL level and BMI.

Intermittent Overconsumption of High Fat Diet Promotes Microglial Reactivity in the Hypothalamus and Hindbrain of Female Rats

Elevated proinflammatory cytokines were reported in binge eating spectrum disorders characterized by intermittent overconsumption during periods of otherwise normal or restricted food intake. It is unknown whether binge eating promotes neuroinflammation, similar to that observed following chronic overconsumption of a high fat diet (HFD) in rodents. Here, we used a rodent model of binge-like eating to test the hypothesis that intermittent overconsumption of HFD promotes microglial reactivity in brain areas that control food intake. To promote overconsumption, one group of rats received chow plus intermittent access to HFD (INT). Control groups received either chow only (CHOW) or chow plus continuous access to HFD (CONT). Following behavioral testing, brains were processed to visualize ionized calcium-binding adaptor molecule 1 (Iba1), a microglial marker. INT rats consumed more calories than the control rats on days when the HFD was available, and fewer calories than the control rats on days when they only had access to chow. Despite consuming fewer total calories and 50% fewer fat calories, lean INT rats developed a pattern of microglial reactivity in feeding-relevant brain areas similar to obese CONT rats. We conclude that intermittent overconsumption of HFD, without diet-induced weight gain, promotes microglial reactivity in brain regions that control feeding.

Pilot application of an inflammation and physiological dysregulation index based on noninvasive salivary biomarkers

BACKGROUND AND OBJECTIVE

Noninvasive salivary biomarkers can be used to assess the cumulative subclinical health impacts of social and environmental stressors. We evaluated seven salivary biomarkers of neuroendocrine and immune functions and a group index of physiological dysregulation based on these biomarkers in a pilot survey in a socioeconomically disadvantaged population.

RESULTS

Participants recruited at subsidized public housing projects in Denver, Colorado, completed a sociodemographic, behavioral, and health questionnaire and used passive drool samplers to collect five saliva samples over the course of 1 day. Samples were tested for the neuroendocrine biomarkers alpha-amylase, cortisol, and dehydroepiandrosterone (DHEA) as well as immune system/inflammation biomarkers C-reactive protein (CRP), interleukin (IL)-1β, IL-6 and total immunoglobulin A (IgA). A composite Inflammation and Physiological Dysregulation Index (IPDI) was calculated as a count of potentially unhealthy values of dichotomized biomarkers. In 20 individuals who completed the survey (average age 46 years, 75% females), allergy to house dust was significantly associated with increased IPDI (adjusted for age) and significantly increased odds of potentially unhealthy values of total IgA, IL-1β, and CRP. Age, obesity, diabetes, allergy to pollen, recent loss of employment, and depression, anxiety, and stress scores from the standard DASS-21 questionnaire were positively but not significantly (0.05 < p < 0.2) associated with IPDI. This project demonstrated an application of a composite index based on noninvasive salivary biomarkers to assess subclinical health impacts of chronic social stressors.

Health Behaviors and Executive Function in Late Adulthood: A Time-Varying Effect Modeling Analysis

OBJECTIVE

Cognitive decline in older adults is a public health issue, with modifiable factors like obesity and sleep potentially influencing this trajectory. Previous research on their relationship with executive function has shown mixed results, particularly across older adulthood.

METHODS

This study utilized time-varying effect modeling (TVEM) to assess the impact of body mass index (BMI) and sleep on executive function in older adults aged 60 to 79, using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 cycles (N = 2543). Executive function was evaluated using the Digit Symbol Substitution Test (DSST).

RESULTS

Findings indicated that while BMI did not significantly affect cognition, adequate sleep (7-8 hours) was linked to better executive function, especially in individuals aged 63 to 65.

CONCLUSION

These results highlight sleep's importance for cognitive health and suggest interventions focusing on sleep and weight management to mitigate age-related cognitive decline.

Calorie Restriction Attenuates Memory Impairment and Reduces Neuroinflammation in Obese Aged Rats

Obesity and aging collectively potentiate inflammatory responses, particularly within the central nervous system. Managing obesity presents a significant challenge, even more so considering the context of aging. Caloric restriction (CR) has been extensively documented in the literature for its multiple health benefits. Motivated by these findings, we hypothesized that CR could serve as a valuable intervention to address the brain alterations and cognitive decline associated with obesity in aged rats. Our investigation revealed that cafeteria diet increased hippocampal and hypothalamic transcripts related to neuroinflammation, along with cognitive deficits determined in the object recognition test in 18-month-old male rats. Western blot data indicate that the obesogenic diet may disrupt the blood-brain barrier and lead to an increase in Toll-like receptor 4 in the hippocampus, events that could contribute to the cognitive deficits observed. Implementing CR after the onset of obesity mitigated neuroinflammatory changes and cognitive impairments. We found that CR increases GABA levels in the hippocampus of aged animals, as demonstrated by liquid chromatography coupled with mass spectrometry analysis. These findings underscore the potential of CR as a therapeutic opportunity to ameliorate the neuroinflammatory and cognitive alterations of obesity, especially in the context of aging.

Tirzepatide administration improves cognitive impairment in HFD mice by regulating the SIRT3-NLRP3 axis

PURPOSE

High-fat diet (HFD) currently is reported that in connection with cognitive impairment. Tirzepatide is a novel dual receptor agonist for glycemic control. But whether Tirzepatide exerts a protective effect in HFD-related cognitive impairment remains to be explore.

METHODS

During the study, the cognitive dysfunction mice model induced by HFD were established. The expressions synapse-associated protein and other target proteins were detected. The oxidative stress parameters, levels of inflammatory cytokine were also detected.

RESULTS

Our findings proved that Tirzepatide administration attenuates high fat diet-related cognitive impairment. Tirzepatide administration suppresses microglia activation, alleviates oxidative stress as well as suppressed the expression of NLRP3 in HFD mice by up-regulating SIRT3 expression. In conclusion, Tirzepatide attenuates HFD-induced cognitive impairment through reducing oxidative stress and neuroinflammation via SIRT3-NLRP3 signaling.

CONCLUSION

This study suggest that Tirzepatide has neuroprotective effects in HFD-related cognitive dysfunction mice model, which provides a promising treatment of HFD-related cognitive impairment.

Smoking and Obesity Interact to Adversely Affect Disease Progression and Cognitive Performance in Multiple Sclerosis

BACKGROUND

Smoking and obesity interact to exacerbate the risk of hypertension, diabetes, and cardiovascular disease, but their potential synergistic effects on outcomes in multiple sclerosis (MS) have not been well studied. We aimed to study whether smoking and obesity interact to affect disease progression and cognitive function in patients with MS.

METHODS

Incident cases from the population-based case-control study Epidemiological Investigation of MS (EIMS) were categorized by smoking and obesity status at diagnosis and followed up to 15 years postdiagnosis through the Swedish MS registry (n = 3336). Cox regression was used to analyze outcomes, including clinical disease worsening (CDW), progression to Expanded Disability Status Scale (EDSS) levels 3 and 4, physical worsening as measured by a 7.5-point increase in the MS Impact Scale (MSIS) physical score, and cognitive decline, defined as an 8-point or greater reduction on the Symbol Digit Modalities Test (SDMT). Interaction effects on the additive scale were assessed by combining dichotomous variables for smoking (nonsmoker = 0, smoker = 1) and obesity (nonobese = 0, obese = 1), yielding four categories: 0/0 (reference category), 0/1, 1/0, and 1/1.

RESULTS

Additive interactions between smoking and obesity were identified for CDW (attributable proportion due to interaction [AP] 0.18, 95% CI 0.03-0.30), progression to EDSS 4 (AP 0.18, 95% CI 0.08-0.26), MSIS-Physical score worsening (AP 0.32, 95% CI 0.21-0.42), and cognitive decline (AP 0.27, 95% CI 0.19-0.35).

CONCLUSIONS

Smoking and obesity appear to synergistically worsen MS progression and cognitive functioning, with the observed additive interactions across most outcomes suggesting that these factors partly share common biological pathways contributing to disease progression.

The phytoestrogen genistein improves hippocampal neurogenesis and cognitive impairment and decreases neuroinflammation in an animal model of metabolic syndrome

Metabolic syndrome (MS) is the medical term for the combination of at least three of the following factors: obesity, hyperlipidemia, hyperglycemia, insulin resistance, and hypertension. The spontaneously hypertensive rat (SHR) is an accepted animal model for the study of human MS that reveals all the features of the syndrome when fed high-fat, high-carbohydrate diets. The intake of high-fat diets in rats has been shown to produce brain neuropathology. In humans, MS increases the risk of cognitive impairment, dementia, and Alzheimer's disease. Genistein (GEN) is a phytoestrogen found in soy that lacks feminizing and carcinogenic effects and was found to have neuroprotective and anti-inflammatory effects in many pathological conditions. Considering that multiple data support that natural phytoestrogens may be therapeutic options for CNS maladies, we aim to elucidate if these properties also apply to a rat model of MS. Thus, GEN effects on neuroinflammation, neurogenesis, and cognition were evaluated in SHR eating a fat/carbohydrate-enriched diet. To characterize the neuropathology and cognitive dysfunction of MS we fed SHR with a high-fat diet (4520 kcal/kg) along with a 20% sucrose solution to drink. MS rats displayed a significant increase in body weight, BMI and obesity indexes along with an increased in fasting glucose levels, glucose intolerance, high blood pressure, and high blood triglyceride levels. MS rats were injected with GEN during 2 weeks a dose of 10 mg/kg. We found that MS rats showed a decreased number of DCX+ neural progenitors in the dentate gyrus and treatment with GEN increased this parameter. Expression of GFAP was increased in the DG and CA1 areas of the hippocampus and treatment decreased astrogliosis in all of them. We measured the expression of IBA1+ microglia in the same regions and classified microglia according to their morphology: we found that MS rats presented an increased proportion of the hypertrophied phenotype and GEN produced a shift in microglial phenotypes toward a ramified type. Furthermore, colocalization of IBA1 with the proinflammatory marker TNFα showed increased proportion of proinflammatory microglia in MS and a reduction with GEN treatment. On the other hand, colocalization with the anti-inflammatory marker Arg1 showed that MS has decreased proportion of anti-inflammatory microglia and GEN treatment increased this parameter. Cognitive dysfunction was evaluated in rats with MS using a battery of behavioral tests that assessed hippocampus-dependent spatial and working memory, such as the novel object recognition test (NOR), the novel object location test (NOL), and the free-movement pattern Y-maze (FMP-YMAZE) and the d-YMAZE. In all of them, MS performed poorly and GEN was able to improve cognitive impairments. These results indicate that GEN was able to exert neuroprotective actions increasing neurogenesis and improving cognitive impairments while decreasing astrogliosis, microgliosis, and neuroinflammatory environment in MS rats. Together, these results open an interesting possibility for proposing this phytoestrogen as a neuroprotective therapy for MS.

Do specific myelin autoantibodies and increased cerebral dopamine neurotrophic factor in the context of inflammation predict the diagnosis of attention deficit hyperactivity disorder in medication-free children?

BACKGROUND

The aim of this study was to investigate the serum levels of anti-myelin basic protein (anti-MBP), anti-myelin oligodentrocyte glycoprotein (anti-MOG), myelin-associated glycoprotein (MAG), high-sensitivity C-reactive protein (hs-CRP), cerebral dopamine neurotrophic factor (CDNF), cerebellin-1, and reelin and their relationships with clinical severity and irritability behaviours in children with attention deficit (AD) hyperactivity disorder (ADHD) and typically developing (TD) healthy controls.

METHODS

In this study, 141 children with ADHD between the ages of 8 and 14 years who were medication-free and 135 TD healthy controls were included. The serum levels of anti-MBP, anti-MOG, MAG, CDNF, hs-CRP, cerebellin, and reelin were measured using enzyme-linked immunosorbent assay kits. The Turgay Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)-based Screening and Evaluation Scale for Attention Deficit and Disruptive Behavior Disorders-Parent Form (TDSM-IV-O) and the affective reactivity index (ARI) scale were used to assess clinical severity and irritability behaviours in the children.

RESULTS

The MAG, CDNF, hs-CRP, reelin, and cerebellin levels were significantly higher in the ADHD group than in the control group, but no significant differences in anti-MBP and anti-MOG levels were found between the groups. Compared with the controls, the patients with ADHD showed significantly higher scores on the ARI self- and parent-report scales. The reelin, hs-CRP, and MAG levels were significantly associated with the TDSM-IV-O AD scores, AD and oppositional defiant (OD) disorder scores and hyperactivity, and OD and conduct disorder scores, respectively. Hs-CRP was significantly associated with anti-MBP and cerebellin levels. In an analysis of covariance, the results were unchanged even after controlling for potential confounders such as age, body mass index, and sex.

CONCLUSION

This study demonstrates that MAG, CDNF, hs-CRP, reelin, and cerebellin levels may play a potential role in the pathogenesis of ADHD.

Sunflower Oil Fortified with Vitamins D and A and Sunflower Lecithin Ameliorated Scopolamine-Induced Cognitive Dysfunction in Mice and Exploration of the Underlying Protective Pathways

The incidence of cognitive disorders is increasing globally, with a reported prevalence of over 50 million individuals affected, and current interventions offer limited efficacy. This study investigates the effects of sunflower oil fortified with sunflower lecithin, vitamin D, and vitamin A on scopolamine-induced cognitive dysfunction in mice and explores the underlying mechanisms. The incidence of cognitive disorders, such as Alzheimer's disease, is increasing yearly, and current interventions offer limited efficacy. Therefore, this research aims to evaluate the cognitive improvement effects of the three added functional factors on mice with learning and memory impairments, along with the associated molecular mechanisms. Behavioral tests, biochemical assays, and real-time quantitative polymerase chain reaction (RT-qPCR) were utilized to examine the intervention effects of these functional factors on scopolamine-induced cognitive impairment in mice. The results revealed that the groups treated with sunflower lecithin and vitamin D significantly enhanced the mice's exploratory behavior, working memory, and spatial memory, with increases of 1.6 times and 4.5 times, respectively, in the open field and novel object recognition tests (VD group). Additionally, these treatments reduced levels of inflammatory markers and IL-6, increased antioxidant GSH levels, and decreased oxidative stress marker MDA levels, with all effects showing significant differences (p < 0.01). The effects were further enhanced when vitamin A was combined with these treatments. Transcriptomic analysis demonstrated that the intervention groups had markedly improved learning and memory abilities through upregulation of key gene expression levels in the PI3K-AKT signaling pathway, cholinergic pathway, and folate biosynthesis pathway. These findings provide a theoretical basis for the development of nutritionally fortified edible oils with added sunflower lecithin, vitamin D, and vitamin A, which may help prevent and ameliorate cognitive disorders.

Association between weight-adjusted waist index and cognitive impairment in Chinese older men: a 7-year longitudinal study

Background

Obesity, through mechanisms such as insulin resistance and systemic low-grade inflammation, can damage the central nervous system and impair cognitive function. Weight-adjusted waist index (WWI) is a novel measure of obesity that may offer more precise assessments of muscle and fat mass. This study aims to investigate the association between WWI and cognitive function in older Chinese men.

Methods

Data from the 2011-2018 China Longitudinal Health and Longevity Survey (CLHLS) were used in this study. WWI and cognitive function were examined in both linear and non-linear situations using Kaplan-Meier survival curves, multivariate Cox regression models, and restricted cubic spline (RCS) regression.

Results

This study included 1,392 older Chinese men aged 65 years and over for whom complete data were available. After controlling for all potential confounding variables, our analysis showed a statistically significant positive association between WWI and cognitive decline. Specifically, for every 1 cm/√kg increase in WWI, the risk of cognitive impairment increased by 17% (HR = 1.17, 95% CI: 1.02-1.35). Using 11.52 cm/√kg as the cutoff point for WWI, we found that High WWI was associated with a 44% increased risk of cognitive impairment compared with Low WWI (HR = 1.44, 95% CI: 1.07-1.96). RCS regression analysis confirmed a linear positive correlation between WWI and cognitive impairment.

Conclusion

Higher WWI is linked to worse cognitive performance in older Chinese men.

Reductive stress: The key pathway in metabolic disorders induced by overnutrition

BACKGROUND

The balance of redox states is crucial for maintaining physiological homeostasis. For decades, the focus has been mainly on the concept of oxidative stress, which is involved in the mechanism of almost all diseases. However, robust evidence has highlighted that reductive stress, the other side of the redox spectrum, plays a pivotal role in the development of various diseases, particularly those related to metabolism and cardiovascular health.

AIM OF REVIEW

In this review, we present an extensive array of evidence for the occurrence of reductive stress and its significant implications mainly in metabolic and cardiovascular diseases.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Reductive stress is defined as a shift in the cellular redox balance towards a more reduced state, characterized by an excess of endogenous reductants (such as NADH, NADPH, and GSH) over their oxidized counterparts (NAD+, NADP+, and GSSG). While oxidative stress has been the predominant mechanism studied in obesity, metabolic disorders, and cardiovascular diseases, growing evidence underscores the critical role of reductive stress. This review discusses how reductive stress contributes to metabolic and cardiovascular pathologies, emphasizing its effects on key cellular processes. For example, excessive NADH accumulation can disrupt mitochondrial function by impairing the electron transport chain, leading to decreased ATP production and increased production of reactive oxygen species. In the endoplasmic reticulum (ER), an excess of reductive equivalents hampers protein folding, triggering ER stress and activating the unfolded protein response, which can lead to insulin resistance and compromised cellular homeostasis. Furthermore, we explore how excessive antioxidant supplementation can exacerbate reductive stress by further shifting the redox balance, potentially undermining the beneficial effects of exercise, impairing cardiovascular health, and aggravating metabolic disorders, particularly in obese individuals. This growing body of evidence calls for a reevaluation of the role of reductive stress in disease pathogenesis and therapeutic interventions.

Neuroinflammation: A Driving Force in the Onset and Progression of Alzheimer's Disease

Background/Objectives: The goal of this commentary is to highlight several key components of the inflammatory process as it relates to amyloid toxicity in Alzheimer's disease (AD), including the role of neuroinflammatory factors and peripheral inflammatory events. Methods: Google Scholar and PubMed were used to find articles with the following keywords: Alzheimer's disease, amyloids, neuroinflammation, peripheral inflammation, microglia, cytokines, and treatments. Sources that were case reports, not peer-reviewed, or older than 30 years were excluded. Abstracts were reviewed first for their relevance before the full text was considered. Methods sections were reviewed to ensure the interventional papers included were randomized controlled trials, meta-analyses, or systematic reviews; however, several literature reviews were also included due to the relevance of their background information. Results: Based on the literature review, we chose to concentrate on microglia, cytokine signaling, and peripheral inflammation markers. We found that microglia activation and subsequent microglia-driven inflammation play a pivotal role in the pathomechanism of AD. Additionally, cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-a) appear to contribute to amyloid accumulation and cell damage. Finally, the increased permeability of the blood-brain barrier (BBB) allows for the peripheral inflammatory process to contribute to the inflammation of the central nervous system (CNS) and amyloid-beta (Aβ) accumulation. Conclusions: Current evidence suggests that the immune system plays a pivotal role in the pathogenesis of AD, both in the CNS and the periphery.

Obesity-associated memory impairment and neuroinflammation precede widespread peripheral perturbations in aged rats

BACKGROUND

Obesity and metabolic syndrome are major public health concerns linked to cognitive decline with aging. Prior work from our lab has demonstrated that short-term high fat diet (HFD) rapidly impairs memory function via a neuroinflammatory mechanism. However, the degree to which these rapid inflammatory changes are unique to the brain is unknown. Moreover, deviations in gut microbiome composition have been associated with obesity and cognitive impairment, but how diet and aging interact to impact the gut microbiome, or how rapidly these changes occur, is less clear. Thus, our study investigated the impact of HFD after two distinct consumption durations: 3 months (to model diet-induced obesity) or 3 days (to detect the rapid changes occurring with HFD) on memory function, anxiety-like behavior, central and peripheral inflammation, and gut microbiome profile in young and aged rats.

RESULTS

Our data indicated that both short-term and long-term HFD consumption impaired memory function and increased anxiety-like behavior in aged, but not young adult, rats. These behavioral changes were accompanied by pro- and anti-inflammatory cytokine dysregulation in the hippocampus and amygdala of aged HFD-fed rats at both time points. However, changes to fasting glucose, insulin, and inflammation in peripheral tissues such as the distal colon and visceral adipose tissue were increased in young and aged rats only after long-term, but not short-term, HFD consumption. Furthermore, while subtle HFD-induced changes to the gut microbiome did occur rapidly, robust age-specific effects were only present following long-term HFD consumption.

CONCLUSIONS

Overall, these data suggest that HFD-evoked neuroinflammation, memory impairment, and anxiety-like behavior in aging develop quicker than, and separately from the peripheral hallmarks of diet-induced obesity.

Obesity Affects Disease Activity and Progression, Cognitive Functioning, and Quality of Life in People With Multiple Sclerosis

BACKGROUND AND OBJECTIVES

While obesity is a known risk factor of the development of multiple sclerosis (MS), its impact on MS disease progression remains unclear. We aimed to investigate the influence of body mass index (BMI) on disease activity and progression, cognitive performance, and health-related quality of life in patients with MS.

METHODS

Patients from an incident population-based case-control study (n = 3,249) were categorized based on BMI status at diagnosis and followed up after diagnosis through the Swedish MS registry. Outcomes included changes in the Expanded Disability Status Scale (EDSS), Multiple Sclerosis Impact Scale 29, and Symbol Digit Modalities Test. The mean follow-up time was 10.6 years (SD 6.1). Linear mixed models were used to analyze long-term changes while Cox regression models assessed the risk of 24-week confirmed disability worsening, time to reach EDSS score 3 and EDSS score 4, the appearance of new lesions on MRI, patient-reported physical and psychological worsening, and processing speed worsening.

RESULTS

Obesity, compared with healthy weight, was associated with a 0.02-point faster annual increase in the EDSS score (β for EDSS score x time 0.02, 95% CI 0.00-0.04). In addition, obesity was linked to a higher risk of reaching EDSS score 3 (HR 1.43, 95% CI 1.17-1.75) and EDSS score 4 (HR 1.40, 95% CI 1.07-1.73) and an increased risk of physical and psychological worsening. New lesions on MRI were more frequent among those with overweight and obesity, compared with those with healthy weight (HR 1.21, 95% CI 1.02-1.44 and HR 1.29, 95% CI 1.03-1.62, respectively). Among those who had not changed BMI group during follow-up, the associations between obesity and unfavorable outcomes became more pronounced, and the HR of cognitive disability worsening was 1.51 (95% CI 1.09-2.09) among those with obesity, compared with nonobese participants.

DISCUSSION

In participants with MS, obesity was associated with faster disease progression, poorer health-related quality of life, and more rapid cognitive decline. Both overweight and obesity were associated with higher MRI activity.

Can brain neurons change identity? Lessons from obesity

It has long been thought that the functional identity of mammalian brain neurons is programmed during development and remains stable throughout adult life; however, certain populations of neurons continue to express active regulators of neuronal identity into adulthood. Prolonged exposure to diet-induced metabolic stress induces features of neuronal identity modification in adult mice, and maladaptive changes in neuronal identity maintenance have been linked to cognitive impairment in humans suffering from neurodegenerative diseases often associated with obesity. Here we discuss how, by unraveling the neurological roots of obesity, we may solve the puzzle of whether mammalian brain neurons retain identity plasticity into adulthood, while advancing knowledge of the pathogenic mechanisms at the interface of metabolic and neurodegenerative disorders.

The potential role of interleukin-6 in the association between inflammation and cognitive performance in obstructive sleep apnea

Background

Interleukin-6 (IL-6) represents one of the main molecules involved in inflammatory responses, which can be altered in either patients with cognitive impairment or obstructive sleep apnea (OSA). The present study aimed to evaluate serum IL-6 levels and cognitive performance in patients with severe OSA (Apnea-Hypopnea Index - AHI >30/h).

Methods

Thirty patients with severe OSA were compared to 15 controls similar in age, sex, and Body Mass Index. All patients underwent a sleep medicine interview, including the Epworth Sleepiness Scale (ESS), a polygraphic cardiorespiratory recording, the Montreal Cognitive Assessment (MoCA), and a blood sample for serum IL-6 assessment.

Results

OSA patients presented higher IL-6 serum levels (Md = 7.38) than controls (Md = 2.20, p < 0.001). Moreover, OSA patients showed lower MoCA (Md = 27.00) and higher ESS scores (Md = 8.00) than controls (Md = 30.00, p < 0.001; Md = 4.00, p = 0.004, respectively). Higher IL-6 serum levels were associated with lower oxygen saturation parameters and MoCA scores.

Conclusions

This study documented an association between inflammation, featured by higher IL-6 serum levels, and both nocturnal hypoxemia and cognitive impairment in OSA patients. Therefore, the increase in IL-6 levels may represent the result of vascular damage and neuroinflammation due to intermittent nocturnal hypoxia and further causing neurocognitive dysfunction in OSA.

Factors associated with eating rate: a systematic review and narrative synthesis informed by socio-ecological model

Accumulating evidence shows associations between rapid eating and overweight. Modifying eating rate might be a potential weight management strategy without imposing additional dietary restrictions. A comprehensive understanding of factors associated with eating speed will help with designing effective interventions. The aim of this review was to synthesise the current state of knowledge on the factors associated with eating rate. The socio-ecological model (SEM) was utilised to scaffold the identified factors. A comprehensive literature search of eleven databases was conducted to identify factors associated with eating rate. The 104 studies that met the inclusion criteria were heterogeneous in design and methods of eating rate measurement. We identified thirty-nine factors that were independently linked to eating speed and mapped them onto the individual, social and environmental levels of the SEM. The majority of the reported factors pertained to the individual characteristics (n = 20) including demographics, cognitive/psychological factors and habitual food oral processing behaviours. Social factors (n = 11) included eating companions, social and cultural norms, and family structure. Environmental factors (n = 8) included food texture and presentation, methods of consumption or background sounds. Measures of body weight, food form and characteristics, food oral processing behaviours and gender, age and ethnicity were the most researched and consistent factors associated with eating rate. A number of other novel and underresearched factors emerged, but these require replication and further research. We highlight directions for further research in this space and potential evidence-based candidates for interventions targeting eating rate.

Age and duration of obesity modulate the inflammatory response and expression of neuroprotective factors in mammalian female brain

Obesity has become a global epidemic and is associated with comorbidities, including diabetes, cardiovascular, and neurodegenerative diseases, among others. While appreciable insight has been gained into the mechanisms of obesity-associated comorbidities, effects of age, and duration of obesity on the female brain remain obscure. To address this gap, adolescent and mature adult female mice were subjected to a high-fat diet (HFD) for 13 or 26 weeks, whereas age-matched controls were fed a standard diet. Subsequently, the expression of inflammatory cytokines, neurotrophic/neuroprotective factors, and markers of microgliosis and astrogliosis were analyzed in the hypothalamus, hippocampus, and cerebral cortex, along with inflammation in visceral adipose tissue. HFD led to a typical obese phenotype in all groups independent of age and duration of HFD. However, the intermediate duration of obesity induced a limited inflammatory response in adolescent females' hypothalamus while the hippocampus, cerebral cortex, and visceral adipose tissue remained unaffected. In contrast, the prolonged duration of obesity resulted in inflammation in all three brain regions and visceral adipose tissue along with upregulation of microgliosis/astrogliosis and suppression of neurotrophic/neuroprotective factors in all brain regions, denoting the duration of obesity as a critical risk factor for neurodegenerative diseases. Importantly, when female mice were older (i.e., mature adult), even the intermediate duration of obesity induced similar adverse effects in all brain regions. Taken together, our findings suggest that (1) both age and duration of obesity have a significant impact on obesity-associated comorbidities and (2) early interventions to end obesity are critical to preserving brain health.

Reversal of high-fat diet-induced cognitive impairment and oxidative stress in the brain through Zingiber officinale supplementation

Obesity is a significant health concern that is correlated with various adverse health outcomes. Diet-induced obesity (DIO) is associated with impaired cognitive function. Pharmacological treatments for obesity are limited and may have serious adverse effects. Zingiber officinale (ZO) has anti-inflammatory and antioxidant effects, in addition to metabolic effects. This study aimed to assess the effects of Zingiber officinale supplementation on cognitive function, anxiety levels, neurotrophin levels, and the inflammatory and oxidative status in the cortex following DIO in mice. Two-month-old male Swiss mice were fed DIO or standard chow for 4 months and subsequently subdivided into the following groups (n = 10 mice/group): (i) control - vehicle (CNT + vehicle); (ii) CNT supplemented with ZO (CNT + ZO); (iii) obese mice (DIO + vehicle); and (iv) obese mice supplemented with ZO (DIO + ZO) (n = 10). Zingiber officinale extract (400 mg/kg/day) was administered for 35 days via oral gavage. The DIO + vehicle group exhibited impaired recognition memory. The CNT + ZO group presented a greater number of crossings in the open field. No difference between the groups was observed in the plus maze test. DIO + vehicle increased the DCFH and carbonylation levels in the cortex. The DIO + vehicle group presented a reduction in catalase activity. The expression of inflammatory or neurotrophin markers in the cerebral cortex was not different. In conclusion, our findings indicate that supplementation with ZO reverses the cognitive impairment in DIO mice and enhances the antioxidant status of the cerebral cortex.

Associations of metabolic syndrome with cognitive function and dementia risk: Evidence from the UK Biobank cohort

AIM

To investigate the associations of metabolic syndrome (MetS) with cognitive function, dementia and its subtypes.

METHODS

Based on the participants recruited by UK Biobank, this study aims to investigate the associations of MetS with cognitive function, dementia and its subtypes. Generalized estimating equations, Cox proportional risk models, and multiple linear regression models were respectively used to assess associations between MetS and dementia-related outcomes.

RESULTS

Among the 363,231 participants, 95,713 had MetS at baseline. The results showed that MetS was significantly associated with cognitive function related to fluid intelligence and prospective memory at follow-up. Among participants aged ≥60 years, MetS was correlated with elevated risk of all-cause dementia, particularly vascular dementia (VaD) [hazard ratio 1.115 (95% confidence interval: 1.047, 1.187), hazard ratio 1.393 (95% confidence interval: 1.233, 1.575), respectively]. With increasing MetS components, the risk of all-cause dementia and VaD tended to be elevated. MetS has also been associated with dementia-related structural changes in the brain, including alterations in overall brain volume, white matter volume, grey matter volume and white matter integrity.

CONCLUSION

MetS was associated with poorer cognitive performance and might increase the risk of all-cause dementia as well as VaD, but the effect on Alzheimer's disease was not significant. Holistic control of the MetS may benefit the prevention and control of cognitive impairment and dementia.

Huang-Lian-Jie-Du decoction alleviates cognitive impairment in high-fat diet-induced obese mice via Trem2/Dap12/Syk pathway

BACKGROUND

Cognitive impairment induced by a high-fat diet (HFD) is common, but its mechanism is largely unknown. Huang-Lian-Jie-Du (HLJD) decoction is a classical and powerful prescription in China. It consists of four medicinal plants and is widely used in traditional Chinese medicines (TCM). Studies have shown that HLJD decoction is effective in treating obesity, depression, and so on. However, the therapeutic mechanism of HLJD is still poorly understood.

PURPOSE

Our study aimed to explore whether inflammatory factors and Trem2/Dap12/Syk pathway are involved in this process and whether HLJD treatment can repair cognitive impairment in HFD-induced obesity.

METHODS

To obtain the obese mice, male mice were treated with HFD (60 Kcal% fat) for 16 weeks. After an additional eight weeks, HLJD decoction was administered orally at doses of 4 and 8 g/kg daily for eight weeks. The mice were then subjected to four behavior tests. Aβ42, total Tau, inflammatory-related, and microglial dysregulation-related markers expression were measured. Molecular docking analysis was also conducted to predict the interaction of the chemical constituents of HLJD with human TREM2, DAP12, and SYK. HLJD at doses of 12.5, 25, and 50 µg/mL or limonin at concentrations of 12.5, 25, and 50 µM were used to treat BV2 cells for 24 h. CCK8 assay and Trem2, Dap12, Syk, and p-Syk expression were measured.

RESULTS

Our study revealed that cognitive impairment was evident in mice treated with HFD, indicating the impact of obesity on cognitive function. The expression of Aβ42 and total Tau in the hippocampus (HIP) was significantly higher in obese (HFD-V) mice compared to normal control (NC-V) mice. The Il6, Il1b, and Il10 mRNA expression levels were also markedly increased in the HIP of obese mice. Furthermore, Trem2, Dap12, p-Syk, and Iba1 expression were elevated in the HIP of obese mice. Importantly, HLJD treatment was found to repair cognitive impairment and lower the protein expression of Aβ42, Tau, Trem2, Dap12, p-Syk, and the expression of Il6, Il1b, and Il10 mRNA in HIP of HFD-V mice. The increased expression of Trem2, Dap12, p-Syk, and Iba1 in HIP after HFD consumption could be reduced after receiving HLJD decoction. The compound Limonin showed a well-predicted binding energy with TREM2, DAP12, and SYK. BV2 cells with HLJD or limonin detected the mRNA expressions of Trem2/Dap12. HLJD at 25 and 50 µg/mL decreased Trem2, Dap12, and p-Syk protein levels in BV2 cells.

CONCLUSION

These results reveal that HLJD treatment could alleviate cognitive impairment in HFD-induced obese mice by controlling the activation of the Trem2/Dap12 pathway and reducing Syk phosphorylation in HIP microglia. HLJD and limonin suppressed Trem2/Dap12/Syk signaling pathway in BV2 cells. HLJD therapy might represent a novel treatment for patients with cognitive impairment induced by obesity.

A Longitudinal Study Investigating Whether Chronic Rhinosinusitis Influences the Subsequent Risk of Developing Dementia

Background/Objectives: Numerous studies have explored the association between chronic rhinosinusitis (CRS) and cognitive decline. However, whether CRS is an independent risk factor for the development of dementia remains unclear. Thus, this retrospective cohort study sought to examine the potential association between CRS and increased incidence and risk of dementia by utilizing a representative population-based cohort dataset. Methods: In this study, we identified 2126 patients with CRS aged >55 years and matched them with 8504 controls to assess the incidence and risk of dementia. Results: We found that the incidence of all-cause dementia in CRS patients was 0.125 per 1000 person-years. The risk of developing all-cause dementia events (adjusted hazard ratio [HR] = 1.0, 95% confidence interval = 0.8-1.3) also did not differ significantly between the control group and the CRS group, irrespective of the CRS phenotype. Subgroup analysis also showed no increased adjusted HR for developing Alzheimer's disease (0.9, 0.7-1.2), Parkinson's disease (0.9, 0.5-1.4), and other types of dementia (1.0, 0.7-1.4) in the CRS group compared to the control group. Conclusions: Therefore, the present study demonstrated that patients over 55 years of age with CRS did not exhibit an increased incidence or risk of dementia compared to individuals without CRS.

Exercise as a Therapeutic Strategy for Obesity: Central and Peripheral Mechanisms

Obesity is a complex, multifactorial condition involving excessive fat accumulation due to an imbalance between energy intake and expenditure, with its global prevalence steadily rising. This condition significantly increases the risk of chronic diseases, including sarcopenia, type 2 diabetes, and cardiovascular diseases, highlighting the need for effective interventions. Exercise has emerged as a potent non-pharmacological approach to combat obesity, targeting both central and peripheral mechanisms that regulate metabolism, energy expenditure, and neurological functions. In the central nervous system, exercise influences appetite, mood, and cognitive functions by modulating the reward system and regulating appetite-controlling hormones to manage energy intake. Concurrently, exercise promotes thermogenesis in adipose tissue and regulates endocrine path-ways and key metabolic organs, such as skeletal muscle and the liver, to enhance fat oxidation and support energy balance. Despite advances in understanding exercise's role in obesity, the precise interaction between the neurobiological and peripheral metabolic pathways remains underexplored, particularly in public health strategies. A better understanding of these interactions could inform more comprehensive obesity management approaches by addressing both central nervous system influences on behavior and peripheral metabolic regulation. This review synthesizes recent insights into these roles, highlighting potential therapeutic strategies targeting both systems for more effective obesity interventions.

Interactive Relations of Body Mass Index, Cardiorespiratory Fitness, and Sex to Cognitive Function in Older Adults

OBJECTIVE

The course of cognitive aging is influenced by multiple health factors. This cross-sectional study investigated the interactive relations between body mass index (BMI), maximum oxygen consumption (VO2max), and sex on neuropsychological outcomes in community-dwelling predominantly older adults.

METHODS

Participants were 164 healthy adults [M (SD) = 64.6 (12.5) years, 56% men, 87% white] who participated in an investigation of cardiovascular risk factors and brain health. Multivariable regression analysis, adjusted for age, education, ethnicity, smoking, alcohol consumption, and depression, examined the interactive relations of BMI, VO2max, and sex to multiple neuropsychological outcomes.

RESULTS

Significant BMI*VO2max*sex interactions for Grooved Pegboard dominant (p = .019) and nondominant (p = .005) hands revealed that men with lower VO2max (l/min) displayed worse performance with each hand as BMI increased (p's < .02). A significant BMI*sex interaction for Logical Memory-Delayed Recall (p = .036) (after adjustment for blood glucose) showed that men, but not women, with higher BMI demonstrated worse performance (p = .036). Lastly, significant main effects indicated that lower VO2max was related to poorer logical memory, and higher BMI was associated with poorer Trail Making B and Stroop interference scores (p's < .05).

CONCLUSIONS

Among men, higher cardiorespiratory fitness may protect against the negative impact of greater BMI on manual dexterity and motor speed, making VO2max a target for intervention. Higher BMI is further associated with poorer executive function and verbal memory (in men), and lower VO2max is associated with poorer verbal memory.

Adiponectin deficiency is a critical factor contributing to cognitive dysfunction in obese mice after sevoflurane exposure

BACKGROUND

The number of major operations performed in obese patients is expected to increase given the growing prevalence of obesity. Obesity is a risk factor for a range of postoperative complications including perioperative neurocognitive disorders. However, the mechanisms underlying this vulnerability are not well defined. We hypothesize that obese subjects are more vulnerable to general anaesthesia induced neurotoxicity due to reduced levels of adiponectin. This hypothesis was tested using a murine surgical model in obese and adiponectin knockout mice exposed to the volatile anaesthetic agent sevoflurane.

METHODS

Obese mice were bred by subjecting C57BL/6 mice to a high fat diet. Cognitive function, neuroinflammatory responses and neuronal degeneration were assessed in both obese and lean mice following exposure to 2 h of sevoflurane to confirm sevoflurane-induced neurotoxicity. Thereafter, to confirm the role of adiponectin deficiency in, adiponectin knockout mice were established and exposed to the sevoflurane. Finally, the neuroprotective effects of adiponectin receptor agonist (AdipoRon) were examined.

RESULTS

Sevoflurane triggered significant cognitive dysfunction, neuroinflammatory responses and neuronal degeneration in the obese mice while no significant impact was observed in the lean mice. Similar cognitive dysfunction and neuronal degeneration were also observed in the adiponectin knockout mice after sevoflurane exposure. Administration of AdipoRon partially prevented the deleterious effects of sevoflurane in both obese and adiponectin knockout mice.

CONCLUSIONS

Our findings demonstrate that obese mice are more susceptible to sevoflurane-induced neurotoxicity and cognitive impairment in which adiponectin deficiency is one of the underlying mechanisms. Treatment with adiponectin receptor agonist ameliorates this vulnerability. These findings may have therapeutic implications in reducing the incidence of anaesthesia related neurotoxicity in obese subjects.

The Hidden Dangers of Sedentary Living: Insights into Molecular, Cellular, and Systemic Mechanisms

With the aging of the global population, neurodegenerative diseases are emerging as a major public health issue. The adoption of a less sedentary lifestyle has been shown to have a beneficial effect on cognitive decline, but the molecular mechanisms responsible are less clear. Here we provide a detailed analysis of the complex molecular, cellular, and systemic mechanisms underlying age-related cognitive decline and how lifestyle choices influence these processes. A review of the evidence from animal models, human studies, and postmortem analyses emphasizes the importance of integrating physical exercise with cognitive, multisensory, and motor stimulation as part of a multifaceted approach to mitigating cognitive decline. We highlight the potential of these non-pharmacological interventions to address key aging hallmarks, such as genomic instability, telomere attrition, and neuroinflammation, and underscore the need for comprehensive and personalized strategies to promote cognitive resilience and healthy aging.

Yeast β-glucan alleviates high-fat diet-induced Alzheimer's disease-like pathologies in rats via the gut-brain axis

Targeting the gut microbiota may be an emerging strategy for the prevention and treatment of Alzheimer's disease (AD). Macro-molecular yeast β-glucan (BG), derived from the yeast of Saccharomyces cerevisiae, regulates the gut microbiota. This study aimed to investigate the effect and mechanism of long-term BG in high-fat diet (HFD)-induced AD-like pathologies from the perspective of the gut microbiota. Here, we found that 80 weeks of BG treatment ameliorated HFD-induced cognitive dysfunction in rats. In the hippocampus, BG alleviated HFD-induced the activation of astrocytes, microglia, NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome pathway, and AD-like pathologies. BG modulated gut dysbiosis through increasing the levels of beneficial bacteria and short-chain fatty acids (SCFAs). BG also attenuated HFD-induced gut barrier impairment. Correlation analysis revealed a close relationship among microbiota, SCFAs, and AD-like pathologies. Furthermore, the fecal microbiota of BG-treated rats and SCFAs treatment mitigated AD-like pathologies via the NLRP3 inflammasome pathway in HFD-fed aged rats. These results suggested that long-term BG promotes the production of SCFAs derived from gut microbiota, which further inhibits NLRP3 inflammasome-mediated neuroinflammation, thereby alleviating HFD-induced AD-like pathologies in rats. BG may become a new strategy for targeting neurodegenerative diseases.

Ceftriaxone reverses diet-induced deficits in goal-directed control

RATIONALE

Obesity is associated with numerous health risks and ever-increasing rates are a significant global concern. However, despite weight loss attempts many people have difficulty maintaining weight loss. Previous studies in animals have shown that chronic access to an obesogenic diet can disrupt goal-directed behavior, impairing the ability of animals to flexibly adjust food-seeking behavior following changes in the value of earned outcomes. Changes in behavioral control have been linked to disruption of glutamate transmission in the dorsal medial striatum (DMS), a region critical for the acquisition and expression of goal-directed behavior.

OBJECTIVES

The goal of this study was to test whether ceftriaxone, a beta-lactam antibiotic shown elsewhere to upregulate the expression of the glutamate transporter GLT-1, would improve goal-directed control following long-term exposure to an obesogenic diet.

METHODS

Male and female rats were given access to either standard chow or chow plus sweetened condensed milk (SCM) for 6 weeks. Access to SCM was ended and rats received daily injections of either ceftriaxone or saline for 6 days. Rats were then trained to press a lever to earn a novel food reward and, finally, were assessed for sensitivity to outcome devaluation. Histological analyses examined changes to GLT-1 protein levels and morphological changes to astrocytes, within the DMS.

RESULTS

We found that ceftriaxone robustly restored goal-directed behavior in animals following long-term exposure to SCM. While we did not observe changes in protein levels of GLT-1 in the DMS, we observed that SCM induced changes in the morphology of astrocytes in the DMS, and that ceftriaxone mitigated these changes.

CONCLUSIONS

These results demonstrate that long-term access to a SCM diet impairs goal-directed behavior while also altering the morphology of astrocytes in the DMS. Furthermore, these results suggest that ceftriaxone administration can reverse the impairment of goal-directed behavior potentially through its actions on astrocytes in decision-making circuitry.

Relationship between Stress and Neuroimmunological Responses and Health Literacy in Newly Diagnosed HIV-Infected Patients: An Exploratory Study

Objectives

We aimed to study self-rated health and psycho-neuroimmunological responses during the initial 6 months after testing positive for human immunodeficiency virus (HIV) and its relationship to health literacy, that is, the ability to take in and understand information about one's illness. Health literacy plays a critical role in patients' ability to adhere to antiretroviral treatment (ART). However, there is a lack of studies on the possible impact of HIV-induced proinflammatory processes on health literacy.

Methods

Twelve patients with newly diagnosed HIV attending an urban Ryan White-funded HIV clinic responded to a questionnaire and had blood samples drawn at baseline (first visit) and after 1, 3, and 6 months, respectively. The questionnaire measured stress, depression, and health literacy. Blood was analyzed for HIV RNA plasma viral load, CD4 cell count, pro- and antistress, and inflammatory markers.

Results

Complete data for the entire 4 collection periods were available for nine patients. Over the 6-month period, mean viral load decreased from 353,714.83 (standard deviation 870,334.61) to 35.89 (14.04) copies/mL (p < 0.001). CD4 cell count increased from 321.08 (167.96) to 592.44 (300.06) cells/mm3 (p < 0.001). Self-rated stress decreased from a baseline mean of 7.33 (2.29) to 3.56 (3.21), on a 0-10 visual analogue scale, at the 6-month follow-up (p < 0.01). C-reactive protein (CRP) decreased from 5757.05 (3146.86) to 2360.84 (2277.33) ng/mL (p < 0.05). Mean health literacy score at baseline was 17.67 (3.50; scale range 0-20) and did not change during the follow-up period. However, increased stress and decreased CRP (p = 0.05) during the 6-month follow-up predicted higher health literacy scores at 6 months.

Conclusion

Both stress and proinflammatory processes in newly diagnosed HIV-infected patients might adversely impact patients' health literacy and thus their capacity to align with treatment guidance.

PDTC improves cognitive impairment in LPS-induced ARDS by regulating miR-181c/NF-κB axis-mediated neuroinflammation

BACKGROUND

Cognitive impairment is a severe complication of acute respiratory distress syndrome (ARDS). Emerging studies have revealed the effects of pyrrolidine dithiocarbamate (PDTC) on improving surgery-induced cognitive impairment. The major aim of the study was to investigate whether PDTC protected against ARDS-induced cognitive dysfunction and to identify the underlying mechanisms involved.

METHODS

The rat model of ARDS was established by intratracheal instillation of lipopolysaccharide (LPS), followed by treatment with PDTC. The cognitive function of rats was analyzed by the Morris Water Maze, and pro-inflammatory cytokines were assessed by quantitative real-time PCR, enzyme-linked immunosorbent assay, and western blot assays. A dual-luciferase reporter gene assay was performed to identify the relationship between miR-181c and its target gene, TAK1 binding protein 2 (TAB2).

RESULTS

The results showed that PDTC improved cognitive impairment and alleviated neuroinflammation in the hippocampus in LPS-induced ARDS model. Furthermore, we demonstrated that miR-181c expression was downregulated in the hippocampus of the ARDS rats, which was restored by PDTC treatment. In vitro studies showed that miR-181c alleviated LPS-induced pro-inflammatory response by inhibiting TAB2, a critical molecule in the nuclear factor (NF)-κB signaling pathway.

CONCLUSION

PDTC improves cognitive impairment in LPS-induced ARDS by regulating miR-181c/NF-κB axis-mediated neuroinflammation, providing a potential opportunity for the treatment of this disease.

Association of obesity indicators with cognitive function among US adults aged 60 years and older: Results from NHANES

BACKGROUND

Midlife obesity is a significant risk factor for Alzheimer's disease, but the effects of obesity on cognitive function, either detrimental or beneficial, are controversial among older individuals. This study aims to assess this associations of body mass index (BMI) or waist circumference (WC) with cognitive function among United States older individuals.

METHODS

A cross-sectional research study was conducted utilizing data from the 2011 to 2014 National Health and Nutrition Examination Survey (NHANES). Initially, the study compared differences in cognitive function among the normal weight, overweight, and obese groups. Subsequently, we examined the relationships between BMI or WC and cognitive function using multivariate linear regression. Finally, structural equation models were constructed to assess the relationships among body shape, lifestyle, and cognitive function pathways.

RESULTS

The study included 2254 individuals. Obese subjects had lower scores in the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) word list learning tasks (CERAD-WL) (χ2 = 7.804, p = .020) and digit symbol substitution test (χ2 = 8.869, p = .012). The regression analysis showed that WC was negatively connected with the CERAD-WL score after adjusting for confounding factors (β = -.029, p = .045). Moreover, WC had a mediating effect on the path from lifestyle to cognition (CERAD-WL). However, there was no difference in the CERAD delayed recall score and the animal fluency test between the obese and the other groups.

CONCLUSIONS

Obese older adults exhibited impaired cognitive abilities in terms of learning and working memory performance. The impact of lifestyle on cognition was mediated by obesity-related anthropometric indices. Sleep, physical activity, and diet influenced the degree of obesity, which subsequently determined cognitive function. Prioritizing weight management in elderly people is crucial for safeguarding cognitive function.

Biological sex and BMI influence the longitudinal evolution of adolescent and young adult MRI-visible perivascular spaces

Background and Purpose

An association recently emerged between magnetic resonance imaging (MRI)-visible perivascular spaces (MV-PVS) with intracerebral solute clearance and neuroinflammation, in adults. However, it is unknown how MV-PVS change throughout adolescence and what factors influence MV-PVS volume and morphology. This study assesses the temporal evolution of MV-PVS volume in adolescents and young adults, and secondarily evaluates the relationship between MV-PVS, age, sex, and body mass index (BMI).

Materials and Methods

This analysis included a 783 participant cohort from the longitudinal multicenter National Consortium on Alcohol and Neurodevelopment in Adolescence study that involved up to 6 imaging visits spanning 5 years. Healthy adolescents aged 12-21 years at study entry with at least two MRI scans were included. The primary outcome was mean MV-PVS volume (mm 3 /white matter cm 3 ).

Results

On average, males had greater MV-PVS volume at all ages compared to females. A linear mixed-effect model for MV-PVS volume was performed. Mean BMI and increases in a person's BMI were associated with increases in MV-PVS volume over time. In females only, changes in BMI correlated with MV-PVS volume. One unit increase in BMI above a person's average BMI was associated with a 0.021 mm 3 /cm 3 increase in MV-PVS volume (p<0.001).

Conclusion

This longitudinal study showed sex differences in MV-PVS features during adolescence and young adulthood. Importantly, we report that increases in BMI from a person's mean BMI are associated with increases in MV-PVS volume in females only. These findings suggest a potential link between MV-PVS, sex, and BMI that warrants future study.

Obesity-induced chronic low-grade inflammation in adipose tissue: A pathway to Alzheimer's disease

Alzheimer's disease (AD) is a leading cause of cognitive impairment worldwide. Overweight and obesity are strongly associated with comorbidities, such as hypertension, diabetes, and insulin resistance (IR), which contribute substantially to the development of AD and subsequent morbidity and mortality. Adipose tissue (AT) is a highly dynamic organ composed of a diverse array of cell types, which can be classified based on their anatomic localization or cellular composition. The expansion and remodeling of AT in the context of obesity involves immunometabolic and functional shifts steered by the intertwined actions of multiple immune cells and cytokine signaling within AT, which contribute to the development of metabolic disorders, IR, and systemic markers of chronic low-grade inflammation. Chronic low-grade inflammation, a prolonged, low-dose stimulation by specific immunogens that can progress from localized sites and affect multiple organs throughout the body, leads to neurodystrophy, increased apoptosis, and disruption of homeostasis, manifesting as brain atrophy and AD-related pathology. In this review, we sought to elucidate the mechanisms by which AT contributes to the onset and progression of AD in obesity through the mediation of chronic low-grade inflammation, particularly focusing on the roles of adipokines and AT-resident immune cells.

Maternal obesity alters fetal neuroinflammation in a murine model of preterm birth

BACKGROUND

Preterm birth from intrauterine infection is a leading cause of neonatal neurologic morbidity. Likewise, maternal obesity is associated with intra-amniotic infection and inflammation. Whether maternal obesity is a risk factor for fetal brain injury that occurs with premature birth remains unknown. This study hypothesized that maternal obesity intensifies fetal neuroinflammation in the setting of premature delivery.

OBJECTIVE

This study aimed to examine the influence of maternal obesity on perinatal neuroinflammatory responses that arise with preterm birth using a murine model.

STUDY DESIGN

Dams with obesity were generated via a high-fat diet that was maintained throughout pregnancy. In parallel, dams without obesity (normal) received a control diet. All dams were paired with males on normal diet. Pregnant dams were randomized to receive an intrauterine administration of bacterial endotoxin (lipopolysaccharide) or the vehicle (phosphate-buffered saline) on embryo day 15.5 of what is typically a 19- to 21-day gestation. Fetal brains were harvested 6 hours after intrauterine administrations, and the expressions of key inflammatory cytokines (Il1b, Il6, and Tnf) and panels of metabolic, immune, and inflammatory genes were analyzed.

RESULTS

With the phosphate-buffered saline, there was no difference in gene expression related to maternal obesity. There were substantial differences in Il6 and immune/inflammatory expression profiles in fetal brains from dams with obesity vs normal dams that received lipopolysaccharide. Few differences were observed among the metabolic genes examined under these conditions. The gene expression pattern associated with maternal obesity correlated with pathways related to white matter injury.

CONCLUSION

The expression of neuroinflammatory markers instigated by bacterial endotoxin via intrauterine lipopolysaccharide was greater in embryo brains obtained from dams with obesity. Expression profiles suggest that in combination with intrauterine inflammation, maternal obesity may increase the risk of fetal white matter injury. Further investigation is warranted to understand the relationship between maternal health and neurologic outcomes associated with prematurity.

High-fat diet and aging-associated memory impairments persist in the absence of microglia in female rats

Aging is associated with a priming of microglia such that they are hypersensitive to further immune challenges. As such high-fat diet during aging can have detrimental effects on cognition that is not seen in the young. However, conflicting findings also suggest that obesity may protect against cognitive decline during aging. Given this uncertainty we aimed here to examine the role of microglia in high-fat, high-sucrose diet (HFSD)-induced changes in cognitive performance in the aging brain. We hypothesised that 8 weeks of HFSD-feeding would alter microglia and the inflammatory milieu in aging and worsen aging-related cognitive deficits in a microglia-dependent manner. We found that both aging and HFSD reduced hippocampal neuron numbers and open field exploration; they also impaired recognition memory. However, the aging-related deficits occurred in the absence of a pro-inflammatory response and the deficits in memory performance persisted after depletion of microglia in the Cx3cr1-Dtr knock-in rat. Our data suggest that mechanisms additional to the acute microglial contribution play a role in aging- and HFSD-associated memory dysfunction.

Impact of elevated body mass index (BMI) on cognitive functioning and inflammation in persons with post-COVID-19 condition: a secondary analysis

BACKGROUND

Individuals who have recovered from the acute stage of SARS-CoV-2 infection may be at risk of developing post-COVID-19 condition (PCC), characterised by a spectrum of persisting, non-specific, and functionally impairing symptoms across multiple organ systems. Obesity has been implicated as a risk factor for PCC, mediated by chronic systemic inflammation. The foregoing has also been separately reported to mediate cognitive dysfunction in PCC.

METHODS

This is a post-hoc analysis of a randomised, double-blinded, placebo-controlled clinical trial evaluating vortioxetine treatment for cognitive impairments in persons with PCC who received vortioxetine or placebo for eight weeks. This analysis comprises baseline data, examining the impact of BMI on cognitive functioning measured by the Digit Symbol Substitution Test (DSST) and Trails Making Tests (TMT)-A/B, as well as inflammation, via serum c-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).

RESULTS

Complete data from 70 participants were statistically analysed and adjusted for age and sex. BMI was negatively correlated with performance on the DSST (β = -0.003, p = 0.047), TMT-A (β = -0.006, p = 0.025), and TMT-B (β = -0.006, p = 0.002). BMI was positively correlated with serum CRP (unstandardized β = 0.193, standardized β = 0.612, p < 0.001) and ESR (β = 0.039, p < 0.001) levels.

CONCLUSION

We observed a significant negative correlation between BMI and cognitive functioning, and a significant positive correlation between BMI and inflammation in persons with PCC, suggesting a bidirectional interplay between BMI, PCC, and cognitive function; individuals with an elevated BMI may be at a greater risk of developing PCC and/or presenting with greater cognitive deficits mediated by chronic systemic inflammation.

Edge Density Imaging Identifies White Matter Biomarkers of Late-Life Obesity and Cognition

Alzheimer disease (AD) and obesity are related to disruptions in the white matter (WM) connectome. We examined the link between the WM connectome and obesity and AD through edge-density imaging/index (EDI), a tractography-based method that characterizes the anatomical embedding of tractography connections. A total of 60 participants, 30 known to convert from normal cognition or mild-cognitive impairment to AD within a minimum of 24 months of follow up, were selected from the Alzheimer disease Neuroimaging Initiative (ADNI). Diffusion-weighted MR images from the baseline scans were used to extract fractional anisotropy (FA) and EDI maps that were subsequently averaged using deterministic WM tractography based on the Desikan-Killiany atlas. Multiple linear and logistic regression analysis were used to identify the weighted sum of tract-specific FA or EDI indices that maximized correlation to body-mass-index (BMI) or conversion to AD. Participants from the Open Access Series of Imaging Studies (OASIS) were used as an independent validation for the BMI findings. The edge-density rich, periventricular, commissural and projection fibers were among the most important WM tracts linking BMI to FA as well as to EDI. WM fibers that contributed significantly to the regression model related to BMI overlapped with those that predicted conversion; specifically in the frontopontine, corticostriatal, and optic radiation pathways. These results were replicated by testing the tract-specific coefficients found using ADNI in the OASIS-4 dataset. WM mapping with EDI enables identification of an abnormal connectome implicated in both obesity and conversion to AD.

A High-Carbohydrate Diet Induces Cognitive Impairment and Promotes Amyloid Burden and Tau Phosphorylation via PI3K/Akt/GSK-3β Pathway in db/db Mice

BACKGROUND

Cognitive impairment is a prevalent complication of type 2 diabetes, influenced significantly by various dietary patterns. High-carbohydrate diets (HCDs) are commonly consumed nowadays; however, the specific impact of HCDs on cognitive function in diabetes remains unclear.

METHODS

The objective of this study was to investigate whether an HCD has effects on cognition in diabetes. Eight-week-old diabetic (db/db) mice and wild-type (WT) mice underwent a twelve-week dietary intervention, including a normal diet (ND), an HCD, or a high-fat diet (HFD). Following this, behavioral tests were conducted, and related hippocampal pathology was evaluated.

RESULTS

Our results demonstrated that an HCD exacerbated cognitive decline in db/db mice compared to an ND. Additionally, an HCD increased amyloid-β burden and expression of β-site APP cleaving enzyme-1. An HCD was also found to promote the phosphorylation of tau protein via the PI3K/Akt/GSK-3β pathway. Furthermore, an HCD markedly induced neuroinflammation and increased the quantity of microglia and astrocytes. However, these damages induced by an HCD were less severe than those caused by an HFD.

CONCLUSIONS

Collectively, our findings indicate that a high intake of carbohydrates can have an adverse impact on cognitive function in diabetes.

Hop (Humulus lupulus L.) extract reverts glycaemic imbalance and cognitive impairment in an animal model of obesity

The rates of overweight and obesity around the world have increased in past years. The body's adipose tissue stimulates the antioxidant and oxidation imbalance capacity at the cellular level. This scenario favors an inflammatory low-grade systemic condition starting with insulin resistance, which in turn may involve diabetes mellitus type 2 and cognitive decline afterward. Neurological diseases have been correlated to senile age diseases over time. This scenario calls for a change in the incidence of obesity in the younger generation. An unhealthy dietary consumption together with sedentary habits might lead to poor gut absorption of nutrients. Several plants and foods have bioactive compounds that can reduce or inhibit radical scavengers, reactive oxygen species, and metal ion complexes that threaten the cerebral defense system. The bitter acids from hops (Humulus lupulus L.) have been demonstrated to have promising effects on lipid and carbohydrate metabolism improvement, reducing inflammatory responses through alpha acids, beta acids, and analogs action. Therefore, the current study aimed to investigate the bioactivity of hop bitter acids in obese and lean mice. For that, a dry hop extract (DHE) was obtained by applying carbon dioxide as the fluid of supercritical extraction. Afterward, seventy-eight male mice of the C57BL/6J strain were weighed and randomly distributed into six groups of 13 animals each according to the diet offered: (NO) normolipidic diet, (NO1) normolipidic diet containing 0.35% alpha acids, (NO2) normolipidic diet containing 3.5% alpha acids, (HP) hyperlipidic diet, (HP1) hyperlipidic diet containing 0.35% alpha acids, and (HP2) hyperlipidic diet containing 3.5% alpha acids. After applying the glycemic tolerance and insulin tolerance tests, a better stabilization of glycemia levels and weight gain among those animals fed with DHE (NO2 and HP2) were observed in comparison to the obese control group (HP) (p < 0.05). There was also an amelioration of antioxidant capacity observed by checking the enzymatic profile by SOD and an apparent mitigation of brain degeneration by checking GSK3β and p-IRS1 proteins expression (p < 0.05). The y-maze cognitive test applied to highlight possible obesity-harmful animal brains did not indicate a statistical difference between the groups. Although the weekly dietary intake between the obese HP2 group (33.32 ± 4.11, p < 0.05) and control HP (42.3 ± 5.88, p < 0.05) was different. The bioactive compounds present in DHE have demonstrated relevant effects on glycemic control, insulin signaling, and the consequent modulatory action of the obesity-related markers with the brain's inflammatory progression.

Inflammation as a mediator between adverse childhood experiences and adult depression: A meta-analytic structural equation model

Exposure to adverse childhood experiences (ACEs) confers a higher risk of developing depression in adulthood, yet the mediation of inflammation remains under debate. To test this model, we conducted a systematic review and two-stage structural equation modelling meta-analysis of studies reporting correlations between ACEs before age 18, inflammatory markers and depression severity in adulthood. Scopus, Pubmed, Medline, PsycInfo, and CINAHL were searched up to 2 October 2023. Twenty-two studies reporting data on C-reactive protein (CRP, n = 12,935), interleukin-6 (IL-6, n = 4108), tumour necrosis factor-α (TNF-α, n = 2256) and composite measures of inflammation (n = 1674) were included. Unadjusted models revealed that CRP (β = 0.003, 95 % LBCI 0.0002 to 0.0068), IL-6 (β = 0.003, 95 % LBCI 0.001 to 0.006), and composite inflammation (β = 0.009, 95 % LBCI 0.004 to 0.018) significantly mediated the association between ACEs and adult depression. The mediation effects no longer survived after adjusting for BMI; however, a serial mediation model revealed that BMI and IL-6 sequentially mediated the association between ACEs and depression (β = 0.002, 95 % LBCI 0.0005 to 0.0046), accounting for 14.59 % and 9.94 % of the variance of IL-6 and depressive symptoms, respectively. Due to the cross-sectional nature of assessment of inflammation and depression findings should be approached with caution; however, results suggest that complex interactions of psychoneuroimmunological and metabolic factors underlie the association between ACEs and adulthood depression.

Cognitive Impairment Induced by Gestational Diabetes: The Role of Oxidative Stress

BACKGROUND

Cognitive impairment is defined as a neurological condition that alters multiple cerebral functions such as reasoning, memory, concentration, and association, among others. It has found to be widely correlated with several factors such as oxidative stress. The latter could be induced by numerous pathological conditions characterized by increased levels of free radicals and decreased levels of antioxidants. Pregnancy is a period when women undergo a physiological state of oxidative stress due to hormonal changes and increased oxygen requirements to maintain pregnancy. However, when oxidative stress exceeds antioxidant capacity, this leads to cellular damage that promotes a diabetogenic state. Recent studies suggest a possible association between gestational diabetes and cognitive impairment, but the underlying mechanisms remain unclear.

AIMS

We aim to explore the pathophysiological relationship between cognitive impairment and oxidative stress, focusing on the possible involvement of oxidative stress as the inducing mechanism.

METHODS

We performed a comprehensive literature review through PubMed and Google Scholar. Our keywords were "neuroinflammation", "cognitive impairment", "gestational diabetes", "oxidative stress", "antioxidants", and "free radicals".

RESULTS

From the initial 400 records identified, a total of 78 studies were analyzed and included in our study.

CONCLUSION

Oxidative stress plays a fundamental role in the development of cognitive impairment. Understanding this correlation is essential to the development of targeted medical interventions and, ultimately, promote research and prevention that will benefit the mother-child binomial in the short and long term.

Elevated interleukin-6 in women with binge-eating spectrum disorders

OBJECTIVE

Binge-eating spectrum disorders (BESD) involve large eating episodes accompanied by a sense of loss of control that occur in individuals with body weights spanning the full body mass index (BMI) spectrum. While research links BESD with peripheral inflammation, this literature is limited by underpowered studies and a failure to control for confounding variables that could promote inflammation independent of dysregulated eating, specifically elevated body adiposity and depression. Our study examined plasma interleukin-6 (IL-6), a marker of peripheral inflammation, in a sample of women with BESD and non-eating disorder controls, controlling for BMI, body adiposity, and depression.

METHOD

Participants (N = 94) included women with BESD (n = 73) or no eating disorder (n = 21) who completed structured clinical interviews in a larger study, selected to represent BMI categories ranging from underweight to obese in both groups. Fasting blood samples were processed for plasma IL-6 concentration via enzyme-linked immunosorbent assays. In addition to assessing group differences in plasma IL-6, exploratory analyses examined associations between IL-6 and biological and clinical markers of BESD.

RESULTS

Significantly elevated plasma IL-6 was found in women with BESD, relative to controls, that was not accounted for by BMI, adiposity, or depression. Plasma IL-6 was positively correlated with plasma leptin concentration, clinical assessments of eating disorder severity, and participants' largest self-reported eating episode.

DISCUSSION

Peripheral inflammation is specifically linked to presence of dysregulated eating independently from weight, adiposity, and depression in BESD. Future research should probe the potential role of neuroinflammation in altered eating behavior.

PUBLIC SIGNIFICANCE

This study provides the first demonstration that inflammation, characterized by elevated plasma IL-6 concentration, is uniquely associated with dysregulated eating in a transdiagnostic group of individuals with BESD. A better understanding of whether immune factors contribute to dysregulated eating could help identify novel biological targets for intervention.

The Impact of Obesity as a Peripheral Disruptor of Brain Inhibitory Mechanisms in Fibromyalgia: A Cross-Sectional Study

Background/Objective: Obesity, characterized by chronic inflammation, may serve as a surrogate marker for more dysfunctional peripheral inflammation, potentially exacerbating FM symptomatology. Given this premise, this study aimed to investigate the effects of obesity as an effect modifier on neural and clinical variables, specifically those indexing pain-compensatory mechanisms in FM symptoms. Methods: A cross-sectional study was conducted with 108 participants who underwent a standardized TMS protocol assessment to measure resting motor threshold (MT), intracortical facilitation (ICF), and intracortical inhibition (ICI). Clinical data were collected using Beck's Depression Index (BDI), PROMIS, the Brief Pain Inventory (BPI), and conditioned pain modulation (CPM). Linear regression models were used to explore the relationship between these variables while examining Body Mass Index (BMI) as a potential effect modifier. If it was found to be a modifier, we stratified the sample into two groups with a BMI cutoff of 30 and performed another regression model within the subgroups. Results: BMI was identified as an effect modifier in the relationships between ICI and BDI, PROMIS fatigue, and CPM and in MT versus CPM. After stratification, non-obese fibromyalgia subjects demonstrated significant correlations between clinical symptoms and CPM and ICI activity. However, these correlations were absent in the obese group, suggesting obesity disrupts pain mechanisms and their compensatory effects. Higher MT values were associated with weaker endogenous pain control, particularly evident in the obese group. Conclusions: Obesity appears to be a significant effect modifier and delineates two patient groups across multiple clinical and neural assessments of fibromyalgia. Additionally, it suggests a role for obesity in exacerbating fibromyalgia symptoms and disrupting physiological pain-inhibitory mechanisms.