The adverse impact of type 2 diabetes on brain volume in heart failure

Cacao Ameliorates Amyloid Beta-Induced Cognitive and Non-Cognitive Disturbances

Background

Alzheimer's disease (AD) is a progressive neurological disorder characterized by a wide range of cognitive and non-cognitive impairments. The present study was designed to investigate the potential effects of cacao on cognitive and non-cognitive performance and to identify the role of oxidative stress in an AD animal model induced by unilateral intracerebroventricular (U-ICV) injection of amyloid beta1-42 (Aβ1-42).

Methods

Oral administration of cacao (0.5 g/kg/day) was performed for 60 consecutive days. Following 60 days, the open-field (OF) test, elevated plus-maze (EPM) test, novel object recognition (NOR) test, Barnes maze (BM) test, and Morris water maze (MWM) test were used to evaluate locomotor activity, anxiety-like behavior, recognition memory, and spatial memory, respectively. Total oxidant status (TOS) and total antioxidant capacity (TAC) in plasma were also examined. Furthermore, the number of healthy cells in the hippocampus's dentate gyrus (DG), CA1, and CA3 regions were identified using hematoxylin and eosin staining.

Results

The results indicated that the injection of Aβ1-42 in rats led to recognition memory and spatial memory impairments, as well as increased anxiety. This was accompanied by decreased total antioxidant capacity (TAC), increased total oxidative stress (TOS), and increased neuronal death. Conversely, cacao treatment in AD rats improved memory function, reduced anxiety, modulated oxidative stress balance, and decreased neuronal death.

Conclusion

The findings suggest that cacao's ability to improve the balance between oxidants and antioxidants and prevent neuronal loss may be the mechanism underlying its beneficial effect against AD-related cognitive and non-cognitive impairments.

Direct Link Between Cardiac Failure and Global Cerebral Atrophy in a Young Adult: A Case Report on Reduced Cerebral Artery Blood Flow

BACKGROUND Heart failure is associated with structural brain abnormalities, including atrophy of multiple brain regions. Previous studies have reported brain atrophy in middle-aged patients with systolic heart failure. In this report, we present the case of a 21-year-old woman with idiopathic dilated cardiomyopathy, cardiac failure, and global cerebral atrophy due to reduced cerebral artery blood flow. We also discuss the impact of brain atrophy in this young adult patient with severe heart failure and no risk factors for atherosclerosis. CASE REPORT A 21-year-old woman with dyspnea and leg edema was admitted to our hospital. After several examinations, an endomyocardial biopsy led to a diagnosis of idiopathic dilated cardiomyopathy, and transthoracic ultrasound cardiography revealed that her left ventricular ejection fraction was 36%. One year after the first hospitalization, her heart failure was classified as New York Heart Association Class III. Magnetic resonance imaging showed severe global brain atrophy, and single-photon emission computed tomography combined with brain computed tomography showed reduced blood flow to the entire brain. She had no risk factors for atherosclerosis and no atherosclerotic changes to her brain or carotid arteries, but her neuropsychological and neurological findings indicated more pronounced brain and cognitive dysfunction. CONCLUSIONS This young adult patient with idiopathic dilated cardiomyopathy, cardiac failure, and global cerebral atrophy showed reduced cerebral artery blood flow and cognitive impairment. The findings of this report indicate that low cardiac output may directly cause brain atrophy in patients with systolic heart failure.

MIND dietary pattern adherence is inversely associated with visceral adiposity and features of metabolic syndrome

The effects of following the Mediterranean-Dietary Approaches to Stop Hypertension (DASH) Intervention for Neurodegenerative Delay (MIND) diet on metabolic health remains understudied. This cross-sectional analysis of 163 adults investigated associations between adherence to the MIND, Mediterranean, DASH, and Healthy Eating Index (HEI-2015) diets and metabolic syndrome (MetS) features and visceral adiposity. We hypothesized that the MIND diet would show the most beneficial associations with MetS risk factors. Diet adherence was assessed using the Dietary History Questionnaire II. Visceral adipose was assessed using dual-energy X-ray absorptiometry. Waist circumference and systolic and diastolic blood pressures were obtained. Fasting blood triglycerides, high-density lipoprotein cholesterol, and glucose concentrations were determined. Stepwise regression analyses were applied. Waist circumference was inversely associated with DASH (β = -0.21, P < .01), HEI-2015 (β = -0.18, P = .01), and MIND (β = -0.19, P < .01). Triglycerides were inversely associated with DASH (β = -0.19, P = .01), HEI-2015 (β = -0.18, P = .02), and MIND (β = -0.23, P < .01). High-density lipoprotein cholesterol was positively associated with Mediterranean (β = 0.18, P = .02) and MIND (β = 0.21, P < .01). Systolic blood pressure was inversely associated with Mediterranean (β = -0.18, P = .02), DASH (β = -0.30, P < .01), HEI-2015 (β = -0.24, P < .01), and MIND (β = -0.25, P < .01). Diastolic blood pressure was inversely associated with Mediterranean (β = -0.26, P < .01), DASH (β = -0.34, P < .01), HEI-2015 (β = -0.24, P < .01), and MIND (β = -0.31, P < .01). Fasting glucose was inversely associated with MIND (β = -0.19, P = .02). Visceral adiposity was inversely associated with Mediterranean (β = -0.19, P < .01), DASH (β = -0.22, P < .01), HEI-2015 (β = -0.22, P < .01), and MIND (β = -0.28, P < .01). Although each diet exhibited potential benefits for metabolic outcomes, only greater MIND diet adherence was associated with lower visceral adiposity and each MetS feature in adults.

Effects of the combination of high-intensity interval training and Ecdysterone on learning and memory abilities, antioxidant enzyme activities, and neuronal population in an Amyloid-beta-induced rat model of Alzheimer's disease

AIMS

Oxidative stress and neuronal death are the primary reasons for the progression of amyloid-beta (Aβ) deposition and cognitive deficits in Alzheimer's disease (AD). Ecdysterone (ecdy), a common derivative of ecdysteroids, possesses free radical scavenging and cognitive-improving effects. High-intensity interval training (HIIT) can be a therapeutic strategy for improving cognitive decline and oxidative stress. The present study was aimed to evaluate the effect of HIIT exercise and ecdy consumption synergistically on the changes in learning and memory functions, activities of hippocampal antioxidant enzymes, and neuronal population after AD induced by Aβ in male rats.

MATERIALS AND METHODS

Following ten days of Aβ injection, HIIT exercise and ecdy treatment (10 mg/kg/day; P.O.) were initiated and continued for eight consecutive weeks in rats. At the end of the treatment period, the rat's learning and memory functions were assessed using Morris water maze and passive avoidance tests. The activity of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GRx), and changes in neuronal population were evaluated in rats' brains.

RESULTS

The results indicated that Aβ injection disrupted spatial/passive avoidance learning and memory in both tests, accompanied by a decrease in the SOD and CAT (as endogenous antioxidants) in rats' hippocampus. Additionally, Aβ injection resulted in neuronal loss in the cerebral cortex and hippocampus. Although the consumption of ecdy separately improved spatial/passive avoidance learning and memory impairments, recovered hippocampal activity of SOD, CAT, GRx, and prevented the hippocampal neuronal loss, its combination along with HIIT resulted in a more powerful and effective amelioration in all the above-mentioned Aβ-neuropathological changes.

CONCLUSION

Our results confirm that a combination of HIIT and ecdy treatment could be a promising potential therapeutic option against AD-associated cognitive decline, owing to their free radical scavenging and neuroprotective properties.

Therapeutic Effects of High-Intensity Interval Training Exercise Alone and Its Combination with Ecdysterone Against Amyloid Beta-Induced Rat Model of Alzheimer's Disease: A Behavioral, Biochemical, and Histological Study

Hippocampal oxidative stress has a vital role in the pathophysiology of Alzheimer's disease (AD)-associated behavioral deficits. Ecdysterone (Ecdy), a natural product and primary steroid hormone, exhibits anti-oxidative and neuroprotective effects. High-intensity interval training (HIIT) has emerged as an effective method for improving physiological brain functions. The present study was designed to investigate the comparative effects of separate and combined HIIT and Ecdy treatment on behavioral functions, hippocampal oxidative status, histological changes in an amyloid-beta (Aβ)-induced rat model of AD. Adult male rats were treated simultaneously with HIIT exercise and Ecdy (10 mg/kg/day; P.O.), starting ten days after Aβ-injection, and they continued for eight consecutive weeks. At the end of the treatment course, the behavioral functions of the rats were assessed by commonly-used behavioral paradigms. Subsequently, brain samples were collected for histological analysis and hippocampus samples were collected for biochemical analysis. Results illustrated that Aβ injection impaired learning and memory performances in both novel object recognition and Barnes maze tests, reduced exploratory/locomotor activities in open field test, enhanced anxiety-like behavior in elevated plus-maze (P < 0.05). These behavioral deficits accompanied hippocampal oxidative stress (decreased total antioxidant capacity content and glutathione peroxidase enzyme activity, increased total oxidant status and malondialdehyde level) and neuronal loss in the cerebral cortex and hippocampus in H&E staining (P < 0.05). HIIT and Ecdy improved anxiety-like behavior, attenuated total oxidant status and malondialdehyde, and prevented the neuronal loss (P < 0.05). However, their combination resulted in a more complete and powerful improvement in all the above-mentioned Aβ-related deficits (P < 0.05). Overall, these data provide evidence that a combination of HIIT and Ecdy treatment improves Aβ-induced behavioral deficits, possibly through ameliorating hippocampal oxidative status and preventing neuronal loss.

The central nervous system and heart failure

The view that chronic heart failure was exclusively a disease of the heart dominated the cardiovascular literature until relatively recently. However, over the last 40 years it has increasingly come to be seen as a multisystem disease. Aside from changes in the sympathetic and parasympathetic nervous systems and the renin-angiotensin-aldosterone system, adaptations to the lungs, muscles and gastrointestinal tract have been clearly documented. It is clear that the brain and CNS are also affected in patients with heart failure, although this is often under recognized. The purpose of this review is to summarize the changes in the structure and biochemical function of the CNS in patients with chronic heart failure and to discuss their potential importance.

Regional Brain Gray Matter Changes in Patients with Type 2 Diabetes Mellitus

Patients with Type 2 diabetes mellitus (T2DM) show cognitive and mood impairment, indicating potential for brain injury in regions that control these functions. However, brain tissue integrity in cognition, anxiety, and depression regulatory sites, and their associations with these functional deficits in T2DM subjects remain unclear. We examined gray matter (GM) changes in 34 T2DM and 88 control subjects using high-resolution T1-weighted images, collected from a 3.0-Tesla magnetic resonance imaging scanner, and assessed anxiety [Beck Anxiety Inventory], depressive symptoms [Beck Depression Inventory-II], and cognition [Montreal Cognitive Assessment]. We also investigated relationships between GM status of cognitive and mood control sites and these scores in T2DM. Significantly increased anxiety (p = 0.003) and depression (p = 0.001), and reduced cognition (p = 0.002) appeared in T2DM over controls. Decreased GM volumes appeared in several regions in T2DM patients, including the prefrontal, hippocampus, amygdala, insular, cingulate, cerebellum, caudate, basal-forebrain, and thalamus areas (p < 0.01). GM volumes were significantly associated with anxiety (r = -0.456,p = 0.009), depression (r = -0.465,p = 0.01), and cognition (r = 0.455,p = 0.009) scores in regions associated with those regulations (prefrontal cortices, hippocampus, para hippocampus, amygdala, insula, cingulate, caudate, thalamus, and cerebellum) in T2DM patients. Patients with T2DM show brain damage in regions that are involved in cognition, anxiety, and depression control, and these tissue alterations are associated with functional deficits. The findings indicate that mood and cognitive deficits in T2DM patients has brain structural basis in the condition.

Extending Inferential Group Analysis in Type 2 Diabetic Patients with Multivariate GLM Implemented in SPM8

Background:

Although voxel based morphometry studies are still the standard for analyzing brain structure, their dependence on massive univariate inferential methods is a limiting factor. A better understanding of brain pathologies can be achieved by applying inferential multivariate methods, which allow the study of multiple dependent variables, e.g. different imaging modalities of the same subject.

Objective:

Given the widespread use of SPM software in the brain imaging community, the main aim of this work is the implementation of massive multivariate inferential analysis as a toolbox in this software package. applied to the use of T1 and T2 structural data from diabetic patients and controls. This implementation was compared with the traditional ANCOVA in SPM and a similar multivariate GLM toolbox (MRM).

Method:

We implemented the new toolbox and tested it by investigating brain alterations on a cohort of twenty-eight type 2 diabetes patients and twenty-six matched healthy controls, using information from both T1 and T2 weighted structural MRI scans, both separately – using standard univariate VBM - and simultaneously, with multivariate analyses.

Results:

Univariate VBM replicated predominantly bilateral changes in basal ganglia and insular regions in type 2 diabetes patients. On the other hand, multivariate analyses replicated key findings of univariate results, while also revealing the thalami as additional foci of pathology.

Conclusion:

While the presented algorithm must be further optimized, the proposed toolbox is the first implementation of multivariate statistics in SPM8 as a user-friendly toolbox, which shows great potential and is ready to be validated in other clinical cohorts and modalities.

Reduced Gray Matter Volume Is Associated With Poorer Instrumental Activities of Daily Living Performance in Heart Failure

BACKGROUND

Heart failure patients require assistance with instrumental activities of daily living in part because of the high rates of cognitive impairment in this population. Structural brain insult (eg, reduced gray matter volume) is theorized to underlie cognitive dysfunction in heart failure, although no study has examined the association among gray matter, cognition, and instrumental activities of daily living in heart failure.

OBJECTIVES

The aim of this study was to investigate the associations among gray matter volume, cognitive function, and functional ability in heart failure.

METHODS

A total of 81 heart failure patients completed a cognitive test battery and the Lawton-Brody self-report questionnaire to assess instrumental activities of daily living. Participants underwent magnetic resonance imaging to quantify total gray matter and subcortical gray matter volume.

RESULTS

Impairments in instrumental activities of daily living were common in this sample of HF patients. Regression analyses controlling for demographic and medical confounders showed that smaller total gray matter volume predicted decreased scores on the instrumental activities of daily living composite, with specific associations noted for medication management and independence in driving. Interaction analyses showed that reduced total gray matter volume interacted with worse attention/executive function and memory to negatively impact instrumental activities of daily living.

CONCLUSIONS

Smaller gray matter volume is associated with greater impairment in instrumental activities of daily living in persons with heart failure, possibly via cognitive dysfunction. Prospective studies are needed to clarify the utility of clinical correlates of gray matter volume (eg, cognitive dysfunction) in identifying heart failure patients at risk for functional decline and determine whether interventions that target improved brain and cognitive function can preserve functional independence in this high-risk population.

Meta-analyses of structural regional cerebral effects in type 1 and type 2 diabetes

Diabetes is associated with macrovascular and microvascular complications and is a major risk factor for neurological and psychiatric disorders, such as dementia and depression. Type 1 diabetes (T1DM) and type 2 diabetes (T2DM) have distinct etiologies and pathophysiological effects while sharing a common endpoint of persistent hyperglycemia. Neuroimaging studies in T1DM have revealed reductions in numerous regions, including the parahippocampal and occipital regions, while in T2DM there have been numerous reports of hippocampal atrophy. This meta-analysis aimed to identify consistent regional abnormalities in cerebral structures in T1DM and T2DM respectively, and also to examine the impact of potential confounds, including age, depression and vascular risk factors. Neuroimaging studies of both voxel-based morphometry (VBM) data and volumetric data were included. Ten T1DM studies (n = 613 patients) and 23 T2DM studies (n = 1364 patients) fulfilled inclusion criteria. The T1DM meta-analysis revealed reduced bilateral thalamus grey matter density in adults. The T2DM meta-analysis revealed reduced global brain volume and regional atrophy in the hippocampi, basal ganglia, and orbitofrontal and occipital lobes. Moreover, hippocampal atrophy in T2DM was not modified by hypertension, although there were more marked reductions in younger patients relative to healthy controls. In conclusion, T1DM and T2DM demonstrated distinct cerebral effects with generalised and specific target areas of grey matter reduction. Thalamic atrophy in T1DM may be a substrate of associated cognitive deficits. In T2DM, global cerebral atrophy may reflect atherosclerotic factors, while hippocampal atrophy was an independent effect providing a potential common neuropathological etiology for the comorbidity of T2DM with dementia and depression.

Cerebral hypoperfusion and glucose hypometabolism: Key pathophysiological modulators promote neurodegeneration, cognitive impairment, and Alzheimer's disease

Aging, hypertension, diabetes, hypoxia/obstructive sleep apnea (OSA), obesity, vitamin B12/folate deficiency, depression, and traumatic brain injury synergistically promote diverse pathological mechanisms including cerebral hypoperfusion and glucose hypometabolism. These risk factors trigger neuroinflammation and oxidative-nitrosative stress that in turn decrease nitric oxide and enhance endothelin, Amyloid-β deposition, cerebral amyloid angiopathy, and blood-brain barrier disruption. Proinflammatory cytokines, endothelin-1, and oxidative-nitrosative stress trigger several pathological feedforward and feedback loops. These upstream factors persist in the brain for decades, upregulating amyloid and tau, before the cognitive decline. These cascades lead to neuronal Ca²⁺ increase, neurodegeneration, cognitive/memory decline, and Alzheimer's disease (AD). However, strategies are available to attenuate cerebral hypoperfusion and glucose hypometabolism and ameliorate cognitive decline. AD is the leading cause of dementia among the elderly. There is significant evidence that pathways involving inflammation and oxidative-nitrosative stress (ONS) play a key pathophysiological role in promoting cognitive dysfunction. Aging and several comorbid conditions mentioned above promote diverse pathologies. These include inflammation, ONS, hypoperfusion, and hypometabolism in the brain. In AD, chronic cerebral hypoperfusion and glucose hypometabolism precede decades before the cognitive decline. These comorbid disease conditions may share and synergistically activate these pathophysiological pathways. Inflammation upregulates cerebrovascular pathology through proinflammatory cytokines, endothelin-1, and nitric oxide (NO). Inflammation-triggered ONS promotes long-term damage involving fatty acids, proteins, DNA, and mitochondria; these amplify and perpetuate several feedforward and feedback pathological loops. The latter includes dysfunctional energy metabolism (compromised mitochondrial ATP production), amyloid-β generation, endothelial dysfunction, and blood-brain-barrier disruption. These lead to decreased cerebral blood flow and chronic cerebral hypoperfusion- that would modulate metabolic dysfunction and neurodegeneration. In essence, hypoperfusion deprives the brain from its two paramount trophic substances, viz., oxygen and nutrients. Consequently, the brain suffers from synaptic dysfunction and neuronal degeneration/loss, leading to both gray and white matter atrophy, cognitive dysfunction, and AD. This Review underscores the importance of treating the above-mentioned comorbid disease conditions to attenuate inflammation and ONS and ameliorate decreased cerebral blood flow and hypometabolism. Additionally, several strategies are described here to control chronic hypoperfusion of the brain and enhance cognition. © 2016 Wiley Periodicals, Inc.

Daily Physical Activity Is Associated with Subcortical Brain Volume and Cognition in Heart Failure

Cognitive impairment in heart failure (HF) is believed to in part stem from structural brain alterations, including shrinkage of subcortical regions. Fortunately, neurocognitive dysfunction in HF can be mitigated by physical activity (PA), though mechanisms for this phenomenon are unclear. PA is protective against age-related cognitive decline that may involve improved structural integrity to brain regions sensitive to aging (e.g., subcortical structures). Yet, no study has examined the benefits of PA on the brain in HF and we sought to do so and clarify related cognitive implications. Fifty older adults with HF completed a neuropsychological battery and wore an accelerometer for 7 days. All participants underwent brain MRI. This study targeted subcortical brain volume given subcortical alterations are often observed in HF and the sensitivity of PA to subcortical structures in other patient populations. Participants averaged 4348.49 (SD=2092.08) steps per day and greater daily steps predicted better attention/executive function, episodic memory, and language abilities, p's<.05. Medical and demographically adjusted regression analyses revealed higher daily steps per day predicted greater subcortical volume, with specific effects for the thalamus and ventral diencephalon, p's<.05. Greater subcortical volume was associated with better attention/executive function, p<.05. Higher daily PA was associated with increased subcortical brain volume and better cognition in older adults with HF. Longitudinal work is needed to clarify whether daily PA can attenuate brain atrophy in HF to reduce accelerated cognitive decline in this population.

Obesity and cognitive dysfunction in heart failure: the role of hypertension, type 2 diabetes, and physical fitness

BACKGROUND

Cognitive impairment is common in heart failure. Obesity is a known risk factor for cognitive dysfunction in heart failure, though the mechanisms remain unclear. Obesity increases risk for conditions like hypertension and type 2 diabetes mellitus (T2DM) as well as poor fitness levels, and this may serve as one possible pathway accounting for association between obesity and cognitive dysfunction.

AIMS

We used structural equation modeling to test whether the combination of hypertension, T2DM, and reduced fitness mediate the association between obesity and cognitive dysfunction.

METHODS

Two hundred heart failure patients completed neuropsychological testing and a physical fitness assessment. Hypertension and T2DM were ascertained via self-report and medical records. Body mass index (BMI) was calculated.

RESULTS

Forty-three percent of the sample was obese. Hypertension (70%) and T2DM (36%) were common, and fitness levels were reduced. The structural equation model with these factors as mediators between BMI and cognitive function demonstrated excellent fit (comparative fit index = 0.98; root mean-square error of approximations = 0.03). Higher BMI correlated with hypertension, T2DM, and poorer fitness. Each of these factors predicted worse cognition. Models that isolated medical comorbidities and physical fitness as the mediator were weaker than the full model.

CONCLUSIONS

Increased risk for medical comorbidities and reduced fitness levels helped to explain the negative effects of obesity on cognitive dysfunction in heart failure. Prospective studies should confirm this pattern and examine how weight loss benefits cognitive function in heart failure.

Magnitude of cognitive dysfunction in adults with type 2 diabetes: a meta-analysis of six cognitive domains and the most frequently reported neuropsychological tests within domains

The objectives were to conduct a meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards to determine effect sizes (Cohen's d) for cognitive dysfunction in adults with type 2 diabetes, relative to nondiabetic controls, and to obtain effect sizes for the most commonly reported neuropsychological tests within domains. Twenty-four studies, totaling 26,137 patients (n = 3351 with diabetes), met study inclusion criteria. Small to moderate effect sizes were obtained for five of six domains: motor function (3 studies, n = 2374; d = -0.36), executive function (12 studies, n = 1784; d = -0.33), processing speed (16 studies, n = 3076; d = -0.33), verbal memory (15 studies, n = 4,608; d = -0.28), and visual memory (6 studies, n = 1754; d = -0.26). Effect size was smallest for attention/concentration (14 studies, n = 23,143; d = -0.19). The following tests demonstrated the most notable performance decrements in diabetes samples: Grooved Pegboard (dominant hand) (d = -0.60), Rey Auditory Verbal Learning Test (immediate) (d = -0.40), Trails B (d = -0.39), Rey-Osterreith Complex Figure (delayed) (d = -0.38), Trails A (d = -0.34), and Stroop Part I (d = -0.28). This study provides effect sizes to power future epidemiological and clinical diabetes research studies examining cognitive function and to help inform the selection of neuropsychological tests.

Central proliferation and neurogenesis is impaired in type 2 diabetes and prediabetes animal models

Type 2 diabetes (T2D) is an important risk factor to suffer dementia, including Alzheimer’s disease (AD), and some neuropathological features observed in dementia could be mediated by T2D metabolic alterations. Since brain atrophy and impaired neurogenesis have been observed both T2D and AD we analyzed central nervous system (CNS) morphological alterations in the db/db mice (leptin receptor KO mice), as a model of long-term insulin resistance and T2D, and in C57Bl6 mice fed with high fat diet (HFD), as a model of diet induced insulin resistance and prediabetes. Db/db mice showed an age-dependent cortical and hippocampal atrophy, whereas in HFD mice cortex and hippocampus were preserved. We also detected increased neurogenesis and cell proliferation rates in young db/db mice when compared with control littermates. Our study shows that metabolic parameters serve as predictors of both atrophy and altered proliferation and neurogenesis in the CNS. Moreover in the cortex, atrophy, cell proliferation and neurogenesis were significantly correlated. Our data suggest that T2D may underline some of the pathological features observed in the dementia process. They also support that blood glucose control in elderly patients could help to slow down dementia evolution and maybe, improve its prognosis.