Metabolic syndrome, prediabetes, and brain abnormalities on mri in patients with manifest arterial disease: the SMART-MR study

Association of Metabolic Syndrome With Neuroimaging and Cognitive Outcomes in the UK Biobank

OBJECTIVE

Metabolic syndrome (MetS) has been linked to dementia. In this study, we examined the association of MetS with neuroimaging and cognition in dementia-free adults, offering insight into the impact of MetS on brain health prior to dementia onset.

RESEARCH DESIGN AND METHODS

We included 37,395 dementia-free adults from the UK Biobank database. MetS was defined as having at least three of the following components: larger waist circumference; elevated levels of triglycerides, blood pressure, HbA1c; or reduced HDL cholesterol levels. Multivariable-adjusted linear regression was used to assess associations of MetS with structural neuroimaging and cognitive domains.

RESULTS

MetS was associated with lower total brain (standardized β: -0.06; 95% CI -0.08, -0.04), gray matter (β: -0.10; 95% CI -0.12, -0.08) and hippocampal (for left side, β: -0.03, 95% CI -0.05, -0.01; for right side, β: -0.04, 95% CI -0.07, -0.02) volumes, and greater white matter hyperintensity (WMH) volume (β: 0.08; 95% CI 0.06, 0.11). Study participants with MetS performed poorer on cognitive tests of working memory (β: -0.10; 95% CI -0.13, -0.07), verbal declarative memory (β: -0.08; 95% CI -0.11, -0.05), processing speed (β: -0.06; 95% CI -0.09, -0.04), verbal and numerical reasoning (β: -0.07; 95% CI -0.09, -0.04), nonverbal reasoning (β: -0.03; 95% CI -0.05, -0.01), and on tests of executive function, where higher scores indicated poorer performance (β: 0.05; 95% CI 0.03, 0.08). More MetS components were also associated with less brain volume, greater WMH, and poorer cognition across all domains.

CONCLUSIONS

MetS was associated poorer brain health in dementia-free adults, characterized by less brain volume, greater vascular pathology, and poorer cognition. Further research is necessary to understand whether reversal or improvement of MetS can improve brain health.

Structural Brain Alterations in Metabolic Syndrome: A Comprehensive MRI Volumetric Analysis of Subcortical and Associated Structures

Objective: This study aims to elucidate the comprehensive effects of metabolic syndrome (MetS) on the structural integrity of subcortical brain regions and associated structures through high-resolution magnetic resonance imaging (MRI) volumetric analysis, thereby contributing to a deeper understanding of the neuroanatomical dimensions of MetS and its potential implications for cognitive functions and overall brain health. Methods: A cross-sectional design was implemented, involving 25 individuals diagnosed with MetS for at least one year and a healthy control group of 15 individuals at a tertiary hospital's family medicine clinic in Eastern Turkey. Participants underwent a high-resolution MRI scan using a 1.5T Siemens Aera scanner. The MRICloud platform was employed for comprehensive segmentation and quantitative analysis of various brain structures. Results: The study revealed significant volumetric reductions in all measured subcortical brain regions among individuals with MetS compared to the control group (all P < 0.05). Notable differences were observed in key structures such as the substantia nigra, corpus callosum, and thalamus. In subcortical structures, the largest volumetric differences were noted in the basal ganglia L (1322.4 mm³), while the most significant percentage differences were seen in the substantia nigra R (25.24%) and caudate nucleus L (21.02%). Conclusion: The findings from this study underscore the significant neuroanatomical changes associated with MetS, manifesting as volumetric reductions in critical subcortical brain areas. These alterations underscore the necessity for further research into the comprehensive influence of MetS on cognitive processes and the potential for early therapeutic interventions.

A latent clinical-anatomical dimension relating metabolic syndrome to brain structure and cognition

The link between metabolic syndrome (MetS) and neurodegenerative as well as cerebrovascular conditions holds substantial implications for brain health in at-risk populations. This study elucidates the complex relationship between MetS and brain health by conducting a comprehensive examination of cardiometabolic risk factors, brain morphology, and cognitive function in 40,087 individuals. Multivariate, data-driven statistics identified a latent dimension linking more severe MetS to widespread brain morphological abnormalities, accounting for up to 71% of shared variance in the data. This dimension was replicable across sub-samples. In a mediation analysis, we could demonstrate that MetS-related brain morphological abnormalities mediated the link between MetS severity and cognitive performance in multiple domains. Employing imaging transcriptomics and connectomics, our results also suggest that MetS-related morphological abnormalities are linked to the regional cellular composition and macroscopic brain network organization. By leveraging extensive, multi-domain data combined with a dimensional stratification approach, our analysis provides profound insights into the association of MetS and brain health. These findings can inform effective therapeutic and risk mitigation strategies aimed at maintaining brain integrity.

A Closer Look at the Perivascular Unit in the Development of Enlarged Perivascular Spaces in Obesity, Metabolic Syndrome, and Type 2 Diabetes Mellitus

The recently described perivascular unit (PVU) resides immediately adjacent to the true capillary neurovascular unit (NVU) in the postcapillary venule and contains the normal-benign perivascular spaces (PVS) and pathological enlarged perivascular spaces (EPVS). The PVS are important in that they have recently been identified to be the construct and the conduit responsible for the delivery of metabolic waste from the interstitial fluid to the ventricular cerebrospinal fluid for disposal into the systemic circulation, termed the glymphatic system. Importantly, the outermost boundary of the PVS is lined by protoplasmic perivascular astrocyte endfeet (pvACef) that communicate with regional neurons. As compared to the well-recognized and described neurovascular unit (NVU) and NVU coupling, the PVU is less well understood and remains an emerging concept. The primary focus of this narrative review is to compare the similarities and differences between these two units and discuss each of their structural and functional relationships and how they relate not only to brain homeostasis but also how they may relate to the development of multiple clinical neurological disease states and specifically how they may relate to obesity, metabolic syndrome, and type 2 diabetes mellitus. Additionally, the concept and importance of a perisynaptic astrocyte coupling to the neuronal synapses with pre- and postsynaptic neurons will also be considered as a perisynaptic unit to provide for the creation of the information transfer in the brain via synaptic transmission and brain homeostasis. Multiple electron microscopic images and illustrations will be utilized in order to help explain these complex units.

A latent clinical-anatomical dimension relating metabolic syndrome to brain structure and cognition

The link between metabolic syndrome (MetS) and neurodegenerative as well cerebrovascular conditions holds substantial implications for brain health in at-risk populations. This study elucidates the complex relationship between MetS and brain health by conducting a comprehensive examination of cardiometabolic risk factors, cortical morphology, and cognitive function in 40,087 individuals. Multivariate, data-driven statistics identified a latent dimension linking more severe MetS to widespread brain morphological abnormalities, accounting for up to 71% of shared variance in the data. This dimension was replicable across sub-samples. In a mediation analysis we could demonstrate that MetS-related brain morphological abnormalities mediated the link between MetS severity and cognitive performance in multiple domains. Employing imaging transcriptomics and connectomics, our results also suggest that MetS-related morphological abnormalities are linked to the regional cellular composition and macroscopic brain network organization. By leveraging extensive, multi-domain data combined with a dimensional stratification approach, our analysis provides profound insights into the association of MetS and brain health. These findings can inform effective therapeutic and risk mitigation strategies aimed at maintaining brain integrity.

Reduced basal macrovascular and microvascular cerebral blood flow in young adults with metabolic syndrome: potential mechanisms

Ninety-million Americans suffer metabolic syndrome (MetSyn), increasing the risk of diabetes and poor brain outcomes, including neuropathology linked to lower cerebral blood flow (CBF), predominantly in anterior regions. We tested the hypothesis that total and regional CBF is lower in MetSyn more so in the anterior brain and explored three potential mechanisms. Thirty-four controls (25 ± 5 yr) and 19 MetSyn (30 ± 9 yr), with no history of cardiovascular disease/medications, underwent four-dimensional flow magnetic resonance imaging (MRI) to quantify macrovascular CBF, whereas arterial spin labeling quantified brain perfusion in a subset (n = 38/53). Contributions of cyclooxygenase (COX; n = 14), nitric oxide synthase (NOS, n = 17), or endothelin receptor A signaling (n = 13) were tested with indomethacin, NG-monomethyl-L-arginine (L-NMMA), and Ambrisentan, respectively. Total CBF was 20 ± 16% lower in MetSyn (725 ± 116 vs. 582 ± 119 mL/min, P < 0.001). Anterior and posterior brain regions were 17 ± 18% and 30 ± 24% lower in MetSyn; reductions were not different between regions (P = 0.112). Global perfusion was 16 ± 14% lower in MetSyn (44 ± 7 vs. 36 ± 5 mL/100 g/min, P = 0.002) and regionally in frontal, occipital, parietal, and temporal lobes (range 15-22%). The decrease in CBF with L-NMMA (P = 0.004) was not different between groups (P = 0.244, n = 14, 3), and Ambrisentan had no effect on either group (P = 0.165, n = 9, 4). Interestingly, indomethacin reduced CBF more in Controls in the anterior brain (P = 0.041), but CBF decrease in posterior was not different between groups (P = 0.151, n = 8, 6). These data indicate that adults with MetSyn exhibit substantially reduced brain perfusion without regional differences. Moreover, this reduction is not due to loss of NOS or gain of ET-1 signaling but rather a loss of COX vasodilation.NEW & NOTEWORTHY We tested the impact of insulin resistance (IR) on resting cerebral blood flow (CBF) in adults with metabolic syndrome (MetSyn). Using MRI and research pharmaceuticals to study the role of NOS, ET-1, or COX signaling, we found that adults with MetSyn exhibit substantially lower CBF that is not explained by changes in NOS or ET-1 signaling. Interestingly, adults with MetSyn show a loss of COX-mediated vasodilation in the anterior but not posterior circulation.

Why Are Perivascular Spaces Important?

Perivascular spaces (PVS) and their enlargement (EPVS) have been gaining interest as EPVS can be visualized non-invasively by magnetic resonance imaging (MRI) when viewing T-2-weighted images. EPVS are most commonly observed in the regions of the basal ganglia and the centrum semiovale; however, they have also been identified in the frontal cortex and hippocampal regions. EPVS are known to be increased in aging and hypertension, and are considered to be a biomarker of cerebral small vessel disease (SVD). Interest in EPVS has been significantly increased because these PVS are now considered to be an essential conduit necessary for the glymphatic pathway to provide the necessary efflux of metabolic waste. Metabolic waste includes misfolded proteins of amyloid beta and tau that are known to accumulate in late-onset Alzheimer's disease (LOAD) within the interstitial fluid that is delivered to the subarachnoid space and eventually the cerebral spinal fluid (CSF). The CSF acts as a sink for accumulating neurotoxicities and allows clinical screening to potentially detect if LOAD may be developing early on in its clinical progression via spinal fluid examination. EPVS are thought to occur by obstruction of the PVS that associates with excessive neuroinflammation, oxidative stress, and vascular stiffening that impairs flow due to a dampening of the arterial and arteriolar pulsatility that aids in the convective flow of the metabolic debris within the glymphatic effluxing system. Additionally, increased EPVS has also been associated with Parkinson's disease and non-age-related multiple sclerosis (MS).

Effect of Metabolic Syndrome Risk Factors on Processing Speed and Executive Function in Three Racialized Groups

BACKGROUND

Metabolic syndrome (MetS) has been associated with increased risk for Alzheimer's disease and related dementias (ADRD). Understanding the association of MetS risk factors to processing speed and executive function in the pre-clinical stages of ADRD in under-represented groups would offer insight on potential mechanisms through which MetS associates with ADRD risk.

OBJECTIVE

Examine association of MetS features and processing speed and executive function across three racial groups.

METHODS

Cognitively unimpaired adults from the Wisconsin Alzheimer's Disease Research Center and the Wisconsin Registry for Alzheimer's Disease Prevention completed blood-draws and neuropsychological testing. Six cognitive outcomes were assessed in association to MetS risk factors: Trailmaking Tests A and B, Animal Fluency, Digit Symbol, and composite scores for Processing Speed and Executive Function. Linear mixed effect models were used to assess the relationship between MetS risk factor count and longitudinal cognitive performance across three racialized groups.

RESULTS

Participant sample sizes varied by outcome analyzed (N = 714-1,088). African American and Native American groups exhibited higher rates of MetS than non-Hispanic Whites. MetS was associated with processing speed and executive function across all racialized groups. Three-way interaction by racialized group was limited to one cognitive outcome: Trailmaking Test A.

CONCLUSION

Metabolic dysfunction incrementally affects cognitive trajectory, with generally similar associations across racial groups. Since racialized groups exhibit higher levels of both MetS and ADRD, MetS may represent a driving factor for increased ADRD risk experience by racialized group and an important and modifiable target through which to reduce risk of ADRD.

Type 2 diabetes mellitus-associated cognitive dysfunction: Advances in potential mechanisms and therapies

Type 2 diabetes (T2D) and its target organ injuries cause distressing impacts on personal health and put an enormous burden on the healthcare system, and increasing attention has been paid to T2D-associated cognitive dysfunction (TDACD). TDACD is characterized by cognitive dysfunction, delayed executive ability, and impeded information-processing speed. Brain imaging data suggest that extensive brain regions are affected in patients with T2D. Based on current findings, a wide spectrum of non-specific neurodegenerative mechanisms that partially overlap with the mechanisms of neurodegenerative diseases is hypothesized to be associated with TDACD. However, it remains unclear whether TDACD is a consequence of T2D or a complication that co-occurs with T2D. Theoretically, anti-diabetes methods are promising neuromodulatory approaches to reduce brain injury in patients with T2D. In this review, we summarize potential mechanisms underlying TDACD and promising neurotropic effects of anti-diabetes methods and some neuroprotective natural compounds. Constructing screening or diagnostic tools and developing targeted treatment and preventive strategies would be expected to reduce the burden of TDACD.

Relations of Metabolic Health and Obesity to Brain Aging in Young to Middle-Aged Adults

Background We aimed to evaluate the association between metabolic health and obesity and brain health measured via magnetic resonance imaging and neurocognitive testing in community dwelling adults. Methods and Results Framingham Heart Study Third Generation Cohort members (n=2170, 46±9 years of age, 54% women) without prevalent diabetes, stroke, dementia, or other neurologic conditions were grouped by metabolic unhealthiness (≥2 criteria for metabolic syndrome) and obesity (body mass index ≥30 kg/m2): metabolically healthy (MH) nonobese, MH obese, metabolically unhealthy (MU) nonobese, and MU obese. We evaluated the relationships of these groups with brain structure (magnetic resonance imaging) and function (neurocognitive tests). In multivariable-adjusted analyses, metabolically unhealthy individuals (MU nonobese and MU obese) had lower total cerebral brain volume compared with the MH nonobese referent group (both P<0.05). Additionally, the MU obese group had greater white matter hyperintensity volume (P=0.004), whereas no association was noted between white matter hyperintensity volume and either groups of metabolic health or obesity alone. Obese individuals had less favorable cognitive scores: MH obese had lower scores on global cognition, Logical Memory-Delayed Recall and Similarities tests, and MU obese had lower scores on Similarities and Visual Reproductions-Delayed tests (all P≤0.04). MU and obese groups had higher free water content and lower fractional anisotropy in several brain regions, consistent with loss of white matter integrity. Conclusions In this cross-sectional cohort study of younger to middle-aged adults, poor metabolic health and obesity were associated with structural and functional evidence of brain aging. Improvement in metabolic health and obesity may present opportunities to improve long-term brain health.

Longitudinal Associations of Newly Diagnosed Prediabetes and Diabetes with Cognitive Function among Chinese Adults Aged 45 Years and Older

With population aging, diabetes mellitus and cognitive function decline are common health problems among older adults worldwide. This longitudinal study is aimed at estimating the longitudinal associations of newly diagnosed prediabetes and diabetes status with cognitive function among Chinese adults aged 45 years and older and evaluating the clinical risk factors associated with cognitive function. Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS). A total of 8716 participants meeting the inclusion criteria were enrolled between 2011 and 2012 at baseline, and 6125 participants completed the follow-up survey in 2018. Cognitive function, newly diagnosed diabetic status, depression, body mass index, and clinical and biochemical measurements were collected. At baseline, the mean age of the participants was 58.93 (SD: 9.76) years, 3987 (45.7%) were males, 1802 (20.7%) participants were newly diagnosed with prediabetes, and 935 (10.7%) were diabetes patients. After adjusting for control variables, diabetes was a significant risk factor for subsequent cognitive decline (unstandardized βestimate = -0.50, 95%CI = -0.98 ~ -0.02). Subgroup analyses found that the association of diabetes with cognitive decline was significant in females. Stratification analyses found that among prediabetes patients, triglyceride concentrations were negatively associated with cognitive function; among diabetes patients, high-sensitivity C-reactive protein was significantly associated with cognitive decline. The newly diagnosed diabetes status at baseline was associated with subsequent cognitive decline among middle-aged and elderly Chinese, especially in females. The management of triglycerides through lifestyle modification for prediabetes and specific adjunctive anti-inflammatory therapy for diabetes might benefit cognitive performance.

Hypertensive Aspects of Cardiometabolic Disorders Are Associated with Lower Brain Microstructure, Perfusion, and Cognition

BACKGROUND

Cardiometabolic disorders (hypertension, diabetes) are key modifiable risk factors for Alzheimer's disease and related disorders. They often co-occur; yet, the extent to which they independently affect brain structure and function is unclear.

OBJECTIVE

We hypothesized their combined effect is greater in associations with cognitive function and neuroimaging biomarkers of white matter (WM) health and cerebral perfusion in a diverse older adult cohort.

METHODS

Participants aged 50-85 years received: clinical evaluation, oral glucose tolerance testing, neuroimaging, cognitive testing, and adjudication. Neuroimaging included: T1 (gray [GM]/WM segmentation, regional volumes/thicknesses); FLAIR (WM hyperintensity volume [WMHv]; arterial spin labeling (cerebral blood flow); diffusion tensor imaging (fractional anisotropy [FA]); and neurite orientation dispersion and density imaging (Free Water). Hypertension (HTN) and impaired glucose tolerance (IGT) were staged and cardiometabolic status was categorized (HTN only, IGT only, IGT+HTN, neither). Multivariable linear regression modeled associations with cognitive and neuroimaging measures (covariates: age, gender, race).

RESULTS

MRI was available for 478 participants (35% mild cognitive impairment, 10% dementia) with mean age 70±8 years, 74% with HTN, 61% with IGT, and 15% self-identified as Black/African-American. IGT+HTN was significantly associated with cognitive impairment, higher WM Free Water and WMHv, lower FA, and lower GM perfusion compared to neither factor. HTN alone was associated with poorer cognition and lower GM perfusion. Cardiometabolic factors were not associated with GM macrostructure (volumes, temporal lobe cortical thickness) or cognitive status.

CONCLUSION

HTN and its co-occurrence with IGT (HTN+IGT) were associated with lower global cognitive performance and reduced GM perfusion and impaired WM microstructure.

Brain Structural Alterations, Diabetes Biomarkers, and Cognitive Performance in Older Adults With Dysglycemia

Despite the high risk of dementia in older adults with type 2 diabetes, the neuroanatomical correlates of cognitive dysfunction that are particularly affected by diabetes are not well characterized. This study is aimed to examine the structural brain alterations in dysglycemic older adults. Using voxel-based morphometric and tract-based spatial statistics, we examined changes in gray matter volume, white matter volume, and microstructural integrity in older adults with prediabetes and diabetes. We also assessed the correlation of these structural changes with diabetes biomarkers and cognitive performance. A total of 74 non-demented older adults (normal, n = 14; prediabetes, n = 37; and diabetes, n = 23) participated in this study and underwent structural and diffusion magnetic resonance imaging (MRI) scans and neuropsychological tests. Subjects with diabetes showed reduced volume of cerebellar gray matter and frontal white matter and diffuse white matter dysintegrity, while those with prediabetes only showed reduced volume of insular gray matter. Atrophic changes in the cerebellum and frontal lobe and frontal white matter dysintegrity were correlated with chronic hyperglycemia and insulin resistance and worse performance in verbal memory recognition and executive function tests. Our findings suggest that chronic hyperglycemia and insulin resistance may alter brain structures forming the fronto-cerebellar network, which may cause cognitive dysfunction in older adults.

Metabolic syndrome, intracranial arterial stenosis and cerebral small vessel disease in community-dwelling populations

BACKGROUND AND PURPOSE

This study aimed to investigate the association of metabolic syndrome (MetS) with both intracranial atherosclerotic stenosis (ICAS) and imaging markers of cerebral small vessel disease (CSVD) in a community-based sample.

METHODS

This study included 943 participants (aged 55.6±9.2 years, 36.1% male) from the community-based Shunyi cohort study. MetS was defined according to the joint interim criteria and quantified by the MetS severity Z-score. ICAS was evaluated by brain magnetic resonance angiography. The MRI markers of CSVD, including white matter hyperintensities (WMHs), lacunes, cerebral microbleeds (CMBs) and enlarged perivascular spaces (EPVS), were assessed. Multiple regression models were used to investigate the association of MetS severity Z-score with ICAS and these CSVD markers.

RESULTS

We found that risk of ICAS (OR=1.75, 95% CI 1.39 to 2.21, p<0.001) increased consistently with MetS severity. MetS severity was significantly associated with higher risks of WMH volume (β=0.11, 95% CI 0.01 to 0.20, p=0.02) and lacunes (OR=1.28, 95% CI 1.03 to 1.59, p=0.03) but not the presence of CMBs (OR=0.93, 95% CI 0.74 to 1.16, p=0.51) and PVS severity (EPVS in basal ganglia: OR=0.96, 95% CI 0.84 to 1.09, p=0.51 and EPVS in white matter: OR=1.09, 95% CI 0.96 to 1.23, p=0.21).

CONCLUSIONS

Our findings suggest that WMH and lacunes share risk factors with atherosclerosis of the cerebral artery, whereas the impact of glucose and lipid metabolic disorder to CMB or EPVS might be weak.

Insulin resistance accounts for metabolic syndrome-related alterations in brain structure

Metabolic syndrome (MetS) is a major public health burden worldwide and associated with brain abnormalities. Although insulin resistance is considered a pivotal feature of MetS, its role in the pathogenesis of MetS‐related brain alterations in the general population is unclear. Therefore, in 973 participants (mean age 52.5 years) of the population‐based Rhineland Study, we assessed brain morphology in relation to MetS and insulin resistance, and evaluated to what extent the pattern of structural brain changes seen in MetS overlap with those associated with insulin resistance. Cortical reconstruction and volumetric segmentation were obtained from high‐resolution brain images at 3 Tesla using FreeSurfer. The relations between metabolic measures and brain structure were assessed through (generalized) linear models. Both MetS and insulin resistance were associated with smaller cortical gray matter volume and thickness, but not with white matter or subcortical gray matter volume. Age‐ and sex‐adjusted vertex‐based brain morphometry demonstrated that MetS and insulin resistance were related to cortical thinning in a similar spatial pattern. Importantly, no independent effect of MetS on cortical gray matter was observed beyond the effect of insulin resistance. Our findings suggest that addressing insulin resistance is critical in the prevention of MetS‐related brain changes in later life.

Metabolic Syndrome and Physical Performance: The Moderating Role of Cognition among Middle-to-Older-Aged Adults

OBJECTIVE

Mobility limitation and cognitive decline are related. Metabolic syndrome (MetS), the clustering of three or more cardiovascular risk factors, is associated with decline in both mobility and cognition. However, the interrelationship among MetS, mobility, and cognition is unknown. This study investigated a proposed pathway where cognition moderates the relationship between MetS and Mobility.

METHOD

Adults ages 45-90 years were recruited. MetS risk factors and mobility performance (Short Physical Performance Battery (SPPB) and gait speed) were evaluated. Cognition was assessed using a comprehensive neuropsychological battery. A factor analysis of neuropsychological test scores yielded three factors: executive function, explicit memory, and semantic/contextual memory. Multivariable linear regression models were used to examine the relationship among MetS, mobility, and cognition.

RESULTS

Of the 74 participants (average age 61 ± 9 years; 41% female; 69% White), 27 (36%) participants manifested MetS. Mean SPPB score was 10.9 ± 1.2 out of 12 and gait speed was 1.0 ± 0.2 m/s. There were no statistically significant differences in mobility by MetS status. However, increase in any one of the MetS risk factors was associated with decreased mobility performance after adjusting for age and gender (SPPB score: β (SE) -.17 (0.08), p < .05; gait speed: -.03 (.01), p < .01). Further adjusting for cognitive factors (SPPB score: explicit memory .31 (.14), p = .03; executive function 0.45 (0.13), p < .01; gait speed: explicit memory 0.04 (0.02), p = .03; executive function 0.06 (0.02), p < .01) moderated the relationships between number of metabolic risk factors and mobility.

CONCLUSION

The relationship between metabolic risk factors and mobility may be moderated by cognitive performance, specifically through executive function and explicit memory.

[The efficacy of ethylmethylhydroxypyridine succinate in patients with cerebrovascular pathology complicated with diabetes mellitus and metabolic syndrome]

Arterial hypertension, diabetes mellitus, obesity and dyslipidemia continue to be the main risk factors for diseases of the circulatory system and the leading causes of mortality in the world, the combination of these diseases significantly increases the likelihood of the development and more rapid progression of cardiovascular and cerebrovascular pathology. Improving approaches to the diagnosis and treatment of these diseases is a priority problem in modern medicine. Currently, there is no universal drug that can influence all stages of pathological process in both cerebrovascular diseases and diabetes mellitus, and the problem of rational use of drugs in patients with comorbid pathology has not been completely resolved. A difficult clinical task includes not only the timely detection of the disease and the correct diagnosis, but also the choice of the safest and most effective medicine. A number of clinical studies have demonstrated the efficacy of mexidol in the treatment of this category of patients, which is determined by its complex, pleiotropic and multimodal mechanisms of action.

Venous dysfunction plays a critical role in "normal" white matter disease of aging

A ubiquitous finding on MRI in older individuals, age-related cerebral white matter hyperintensities (WMHs) are associated with cognitive decline, dementia, disability, and death. Currently, these findings are thought to represent small infarcts secondary to lipohyalinotic arteriosclerosis. Commonly though, the anatomic distribution of WMHs is often non-arterial, and parallel the deep venous system. Furthermore, there is discrepant evidence for the role of conventional vascular risk factors such as hypertension, carotid atherosclerosis and diabetes for the development and progression of these. Interventions targeting conventional vascular risk factors lack consistency in preventing the progression of WMHs. There is evidence for age-related hemodynamic cervical venous dysfunction resulting in reduced internal jugular vein venous compliance, venous dilatation, and venous reflux. Similarly, venous collagenosis increases with age. Increased blood-brain barrier (BBB) permeability is also noted with aging. Both hemodynamic venous dysfunction, venous sclerosis, and increased BBB permeability are associated with WMHs. We propose that age-related WMHs are a sequalae of venous dysfunction. Venous dysfunction results initially in increased transmission of venous pressures to the brain. Subsequent BBB disruption leads to increased permeability with progression to end-stage findings of age-related WMHs.

Association of mid-life serum lipid levels with late-life brain volumes: The atherosclerosis risk in communities neurocognitive study (ARICNCS)

BACKGROUND

Limited information exists regarding the association between midlife lipid levels and late-life total and regional brain volumes.

METHODS

We studied 1872 participants in the longitudinal community-based Atherosclerosis Risk in Communities Neurocognitive Study. Serum lipid levels were measured in 1987-1989 (mean age, 53 ± 5 years). Participants underwent 3T brain MRI scans in 2011-2013. Brain volumes were measured using FreeSurfer image analysis software. Linear regression models were used to assess the associations between serum lipids and brain volumes modeled in standard deviation (SD) units, adjusting for potential confounders.

RESULTS

In adjusted analyses, one SD higher low-density lipoprotein cholesterol (LDL) levels were associated with larger total brain volumes (β 0.033, 95% CI 0.006-0.060) as well as larger volumes of the temporal (β 0.038, 95% CI 0.003-0.074) and parietal lobes (β 0.044, 95% CI 0.009-0.07) and Alzheimer disease-related region (β 0.048, 95% CI 0.048-0.085). Higher triglyceride levels were associated with smaller total brain volumes (β -0.033, 95% CI -0.060, -0.007). The associations between LDL levels and brain volumes were modified by age (P for interaction <0.001), with higher LDL levels associated with larger total and regional brain volumes only among adults >53 years at baseline, and were attenuated after application of weights to account for informative attrition, although associations with the parietal and Alzheimer's disease-related region remained significant. High-density lipoprotein cholesterol was not associated with brain volumes.

CONCLUSION

Higher LDL levels in late midlife were associated with larger brain volumes later in life, while higher triglyceride levels were associated with smaller brain volumes. These associations were driven by adults >53 years at baseline.

Association of White Matter Hyperintensities and Cardiovascular Disease: The Importance of Microcirculatory Disease

Cardiac and cerebrovascular diseases are currently the leading causes of mortality and disability worldwide. Both the heart and brain display similar vascular anatomy, with large conduit arteries running on the surface of the organ providing tissue perfusion through an intricate network of penetrating small vessels. Both organs rely on fine tuning of local blood flow to match metabolic demand. Blood flow regulation requires adequate functioning of the microcirculation in both organs, with loss of microvascular function, termed small vessel disease (SVD) underlying different potential clinical manifestations. SVD in the heart, known as coronary microvascular dysfunction, can cause chronic or acute myocardial ischemia and may lead to development of heart failure. In the brain, cerebral SVD can cause an acute stroke syndrome known as lacunar stroke or more subtle pathological alterations of the brain parenchyma, which may eventually lead to neurological deficits or cognitive decline in the long term. Coronary microcirculation cannot be visualized in vivo in humans, and functional information can be deduced by measuring the coronary flow reserve. The diagnosis of cerebral SVD is largely based on brain magnetic resonance imaging, with white matter hyperintensities, microbleeds, and brain atrophy reflecting key structural changes. There is evidence that such structural changes reflect underlying cerebral SVD. Here, we review interactions between SVD and cardiovascular risk factors, and we discuss the evidence linking cerebral SVD with large vessel atheroma, atrial fibrillation, heart failure, and heart valve disease.

Cardiometabolic Health and Longitudinal Progression of White Matter Hyperintensity: The Mayo Clinic Study of Aging

Background and Purpose- White matter hyperintensity (WMH) burden is associated with stroke and cognitive decline. Risk factors associated with the longitudinal progression of WMH in the general population have not been systematically investigated. To investigate the primary midlife and current cardiometabolic risk factors associated with changes in WMH over time in a population cohort. Methods- This cohort study included participants enrolled in the Mayo Clinic Study of Aging, a longitudinal population-based study in Olmsted County, Minnesota with at least 2 consecutive WMH assessments on fluid-attenuated inversion recovery-magnetic resonance images (n=554, ≥60 years with midlife assessments) with relevant baseline laboratory measures of interest. Linear mixed model regression was used to determine the important components of cardiometabolic risk profile at baseline that were associated with future progression of WMH. These analyses were controlled for age and sex. Sensitivity analyses were conducted using stratification by sex. The main outcome measure was percent change in WMH normalized to total intracranial volume. Three sets of models were constructed to evaluate individual (1) midlife risk factors, (2) current risk factors including the presence of metabolic syndrome and its constituents, and (3) baseline measurements of continuous laboratory measures of cardiometabolic risk. Results- Age was the strongest predictor of progression in WMH (P<0.001). Baseline hypertension (P<0.001), midlife hypertension (P=0.003), and baseline fasting glucose in males (P=0.01) were predictive of WMH change. The presence of metabolic syndrome was not associated with progressive WMH. In sensitivity analyses, associations between hypertension and WMH progression were stronger in females. Baseline serum glucose was associated with increase in WMH but was not significant in females in the stratified analysis. Other continuous laboratory measures of vascular risk were not associated with progressive WMH. Conclusions- Midlife and current hypertension in all participants and fasting glucose in males were associated with quantitative changes in white matter. Prospective clinical studies should determine optimal blood pressure to reduce stroke and cognitive impairment during aging.

Brain involvement in non-alcoholic fatty liver disease (NAFLD): A systematic review

Non-alcoholic fatty liver disease (NAFLD) is associated with high cardiovascular morbidity and mortality which usually is considered to be related to cardiac involvement, while scarce attention is addressed to brain damage. Viceversa NAFLD is associated with asymptomatic brain lesions, alterations in cerebral perfusion and activity, cognitive impairment and brain aging and with increased risk and severity of both ischemic and haemorrhagic stroke. Besides known metabolic risk factors, NAFLD is characterized by a pro inflammatory state, which contributes to atherosclerosis and microglia activation, endothelial dysfunction, pro-coagulant state and platelets activation, which in turn promote both micro and macrovascular damage eventually responsible for clinical and subclinical cerebrovascular alterations. A better knowledge of the association between NAFLD and brain alterations could lead to an improved management of risk factors underpinning both liver and cerebral disease, possibly preventing the progression of asymptomatic brain lesions to clinical cerebrovascular accidents.

Characterization of White Matter Hyperintensities in Large-Scale MRI-Studies

Background: White matter hyperintensities of presumed vascular origin (WMH) are a common finding in elderly people and a growing social malady in the aging western societies. As a manifestation of cerebral small vessel disease, WMH are considered to be a vascular contributor to various sequelae such as cognitive decline, dementia, depression, stroke as well as gait and balance problems. While pathophysiology and therapeutical options remain unclear, large-scale studies have improved the understanding of WMH, particularly by quantitative assessment of WMH. In this review, we aimed to provide an overview of the characteristics, research subjects and segmentation techniques of these studies.

Methods: We performed a systematic review according to the PRISMA statement. One thousand one hundred and ninety-six potentially relevant articles were identified via PubMed search. Six further articles classified as relevant were added manually. After applying a catalog of exclusion criteria, remaining articles were read full-text and the following information was extracted into a standardized form: year of publication, sample size, mean age of subjects in the study, the cohort included, and segmentation details like the definition of WMH, the segmentation method, reference to methods papers as well as validation measurements.

Results: Our search resulted in the inclusion and full-text review of 137 articles. One hundred and thirty-four of them belonged to 37 prospective cohort studies. Median sample size was 1,030 with no increase over the covered years. Eighty studies investigated in the association of WMH and risk factors. Most of them focussed on arterial hypertension, diabetes mellitus type II and Apo E genotype and inflammatory markers. Sixty-three studies analyzed the association of WMH and secondary conditions like cognitive decline, mood disorder and brain atrophy. Studies applied various methods based on manual (3), semi-automated (57), and automated segmentation techniques (75). Only 18% of the articles referred to an explicit definition of WMH.

Discussion: The review yielded a large number of studies engaged in WMH research. A remarkable variety of segmentation techniques was applied, and only a minority referred to a clear definition of WMH. Most addressed topics were risk factors and secondary clinical conditions. In conclusion, WMH research is a vivid field with a need for further standardization regarding definitions and used methods.

Participating in Mental, Social, and Physical Leisure Activities and Having a Rich Social Network Reduce the Incidence of Diabetes-Related Dementia in a Cohort of Swedish Older Adults

OBJECTIVE

The effect of a healthy lifestyle on diabetes-related dementia remains unknown. We examined whether an active lifestyle and rich social network may counteract the increased risk of dementia in people with diabetes.

RESEARCH DESIGN AND METHODS

Dementia-free older adults from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) (n = 2,650) were followed up for 10 years. Diabetes was ascertained on the basis of medical history, medication use, medical records, or glycated hemoglobin (HbA_1c) ≥6.5% and prediabetes as HbA_1c between 5.7 and 6.5%. Dementia was diagnosed by specialists following standard criteria. An active lifestyle was defined as a moderate to high (vs. low) level of engagement in leisure activities or a rich social network (having moderate to rich [vs. poor] social connections and support). Hazard ratios (HRs) of dementia risk were derived from Cox regression models.

RESULTS

There were 246 incident dementia cases during follow-up. Those with diabetes (n = 243), but not those with prediabetes (n = 921), had greater risk of dementia (adjusted HR 2.0 [95% CI 1.4-2.9]) than diabetes-free participants. Participants with diabetes but low level of engagement in leisure activities (HR 4.2 [95% CI 2.2-8.2]) or a poor social network (HR 3.4 [95% CI 1.9-6.1]) had greater dementia risk than diabetes-free participants with moderate to high levels of leisure activity engagement or a moderate to rich social network. In participants with diabetes, an active lifestyle (high level of engagement in leisure activities or a rich social network) was associated with less of a raised risk (HR 1.9 [95% CI 1.1-3.4]).

CONCLUSIONS

An active and socially integrated lifestyle may significantly counteract the detrimental effect of diabetes on dementia risk.

Reward-related brain structures are smaller in patients with schizophrenia and comorbid metabolic syndrome

OBJECTIVE

Metabolic syndrome (MS) is highly prevalent in schizophrenia and often a consequence of unhealthy behaviour. Reward-related brain areas might be associated with MS, since they play a major role in regulating health behaviour. This study examined the relationship between MS and brain volumes related to the reward system in schizophrenia.

METHOD

We included patients with schizophrenia, with MS (MS+; n = 23), patients with schizophrenia, without MS (MS-; n = 48), and healthy controls (n = 54). Global brain volumes and volumes of (sub)cortical areas, part of the reward circuit, were compared between patients and controls. In case of a significant brain volume difference between patients and controls, the impact of MS in schizophrenia was examined.

RESULTS

Patients had smaller total brain (TB; P = 0.001), GM (P = 0.010), larger ventricles (P = 0.026), and smaller reward circuit volume (P < 0.001) than controls. MS+ had smaller TB (P = 0.017), GM (P = 0.008), larger ventricles (P = 0.015), and smaller reward circuit volume (P = 0.002) than MS-. MS+ had smaller orbitofrontal cortex (OFC; P = 0.002) and insula volumes (P = 0.005) and smaller OFC (P = 0.008) and insula cortical surface area (P = 0.025) compared to MS-.

CONCLUSION

In schizophrenia, structural brain volume reductions in areas of the reward circuitry appear to be related to comorbid MS.

Sex-related differences in the prevalence of cognitive impairment among overweight and obese adults with type 2 diabetes

INTRODUCTION

Type 2 diabetes mellitus and obesity may increase risks for cognitive decline as individuals age. It is unknown whether this results in different prevalences of cognitive impairment for women and men.

METHODS

The Action for Health in Diabetes, a randomized controlled clinical trial of a 10-year intensive lifestyle intervention, adjudicated cases of cross-sectional cognitive impairment (mild cognitive impairment or dementia) 10-13 years after enrollment in 3802 individuals (61% women).

RESULTS

The cross-sectional prevalences of cognitive impairment were 8.3% (women) and 14.8% (men): adjusted odds ratio 0.55, 95% confidence interval [0.43, 0.71], P < .001. Demographic, clinical, and lifestyle risk factors varied between women and men but did not account for this difference, which was limited to individuals without apolipoprotein E (APOE)-ε4 alleles (interaction P = .034).

CONCLUSIONS

Among overweight and obese adults with type 2 diabetes mellitus, traditional risk factors did not account for the lower prevalence of cognitive impairment observed in women compared with men.

Intermittent living; the use of ancient challenges as a vaccine against the deleterious effects of modern life - A hypothesis

Chronic non-communicable diseases (CNCD) are the leading cause of mortality in developed countries. They ensue from the sum of modern anthropogenic risk factors, including high calorie nutrition, malnutrition, sedentary lifestyle, social stress, environmental toxins, politics and economic factors. Many of these factors are beyond the span of control of individuals, suggesting that CNCD are inevitable. However, various studies, ours included, show that the use of intermittent challenges with hormetic effects improve subjective and objective wellbeing of individuals with CNCD, while having favourable effects on immunological, metabolic and behavioural indices. Intermittent cold, heat, fasting and hypoxia, together with phytochemicals in multiple food products, have widespread influence on many pathways related with overall health. Until recently, most of the employed challenges with hormetic effects belonged to the usual transient live experiences of our ancestors. Our hypothesis; we conclude that, whereas the total inflammatory load of multi-metabolic and psychological risk factors causes low grade inflammation and aging, the use of intermittent challenges, united in a 7-10 days lasting hormetic intervention, might serve as a vaccine against the deleterious effects of chronic low grade inflammation and it's metabolic and (premature) aging consequences.

Metabolically healthy obesity and risk of leukoaraiosis; a population based cross-sectional study

Metabolically healthy obese (MHO) individual is known to be defended from the metabolic complications of obesity. Leukoaraiosis, which is commonly detected on brain magnetic resonance imaging (MRI), is now recognized as a risk of stroke, dementia and death. However, the association between MHO and the prevalence of leukoaraiosis is unclear. In this cross-sectional study of 796 participants who received a medical examination program, we investigated the association between MHO and the prevalence of leukoaraiosis. We used common clinical markers for definition of metabolic healthy status: blood pressure, fasting plasma glucose, triglycerides and high-density lipoprotein cholesterol concentrations. Obesity was defined by body mass index ≥25.0 kg/m². We diagnosed leukoaraiosis by fluid-attenuated inversion recovery without hypointensity on T1-weighted images or the presence of a hyperintensity on T2-weighted images. The crude prevalence proportion of leukoaraiosis was 44.5% (case/n = 171/384) in metabolically healthy nonobese (MHNO) individual, 46.3% (44/95) in MHO individual, 62.3% (114/183) in metabolically unhealthy nonobese (MUNO) individual or 56.6% (77/136) in MUO individual. The odds ratios of prevalence of leukoaraiosis were 1.19 (95% CI 0.74-1.90, p = 0.471) for MHO, 1.79 (1.22-2.62, p = 0.003) for MUNO and 1.56 (1.03-2.37, p = 0.037) for MUO individuals after adjusting for sex, age, smoking statues, habit of exercise and alcohol, compared with MHNO individual. We revealed that MHO individuals were not related with the higher risk of leukoaraiosis, whereas MUNO and MUO individuals were.

Obesity, dyslipidemia and brain age in first-episode psychosis

INTRODUCTION

Obesity and dyslipidemia may negatively affect brain health and are frequent medical comorbidities of schizophrenia and related disorders. Despite the high burden of metabolic disorders, little is known about their effects on brain structure in psychosis. We investigated, whether obesity or dyslipidemia contributed to brain alterations in first-episode psychosis (FEP).

METHODS

120 participants with FEP, who were undergoing their first psychiatric hospitalization, had <24 months of untreated psychosis and were 18-35 years old and 114 controls within the same age range participated in the study. We acquired 3T brain structural MRI, fasting lipids and body mass index. We used machine learning trained on an independent sample of 504 controls to estimate the individual brain age of study participants and calculated the BrainAGE score by subtracting the chronological from the estimated brain age.

RESULTS

In a multiple regression model, the diagnosis of FEP (B = 1.15, SE B = 0.31, p < 0.001) and obesity/overweight (B = 0.92, SE B = 0.35, p = 0.008) were each additively associated with BrainAGE scores (R² = 0.22, F(3, 230) = 21.92, p < 0.001). BrainAGE scores were highest in participants with FEP and obesity/overweight (3.83 years, 95%CI = 2.35-5.31) and lowest in normal weight controls (-0.27 years, 95%CI = -1.22-0.69). LDL-cholesterol, HDL-cholesterol or triglycerides were not associated with BrainAGE scores.

CONCLUSIONS

Overweight/obesity may be an independent risk factor for diffuse brain alterations manifesting as advanced brain age already early in the course of psychosis. These findings raise the possibility that targeting metabolic health and intervening already at the level of overweight/obesity could slow brain ageing in FEP.

White matter microstructure and cognitive decline in metabolic syndrome: a review of diffusion tensor imaging

Metabolic syndrome is a cluster of cardiovascular risk factors defined by the presence of abdominal obesity, glucose intolerance, hypertension and/or dyslipidemia. It is a major public health epidemic worldwide, and a known risk factor for the development of cognitive dysfunction and dementia. Several studies have demonstrated a positive association between the presence of metabolic syndrome and worse cognitive outcomes, however, evidence of brain structure pathology is limited. Diffusion tensor imaging has offered new opportunities to detect microstructural white matter changes in metabolic syndrome, and a possibility to detect associations between functional and structural abnormalities. This review analyzes the impact of metabolic syndrome on white matter microstructural integrity, brain structure abnormalities and their relationship to cognitive function. Each of the metabolic syndrome components exerts a specific signature of white matter microstructural abnormalities. Metabolic syndrome and its components exert both additive/synergistic, as well as, independent effects on brain microstructure thus accelerating brain aging and cognitive decline.

Diabetes, Prediabetes, and Brain Volumes and Subclinical Cerebrovascular Disease on MRI: The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

OBJECTIVE

To examine the associations of prediabetes, diabetes, and diabetes severity (as assessed by HbA_1c and diabetes duration) with brain volumes and vascular pathology on brain MRI and to assess whether the associations of diabetes with brain volumes are mediated by brain vascular pathology.

RESEARCH DESIGN AND METHODS

Cross-sectional study of 1,713 participants in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS) (mean age 75 years, 60% female, 27% black, 30% prediabetes, and 35% diabetes) who underwent 3T brain MRI scans in 2011-2013. Participants were categorized by diabetes-HbA_1c status as without diabetes (<5.7% [reference]), with prediabetes (5.7 to <6.5%), and with diabetes ([defined as prior diagnosis or HbA_1c ≥6.5%] <7.0% vs. ≥7.0%), with further stratification by diabetes duration (<10 vs. ≥10 years).

RESULTS

In adjusted analyses, compared with participants without diabetes and HbA_1c <5.7%, participants with prediabetes and those with diabetes and HbA_1c <7.0% did not have significantly different brain volumes or vascular pathology (all P > 0.05), but those with diabetes and HbA_1c ≥7.0% had smaller total brain volume (β -0.20 SDs, 95% CI -0.31, -0.09), smaller regional brain volumes (including frontal, temporal, occipital, and parietal lobes; deep gray matter; Alzheimer disease signature region; and hippocampus [all P < 0.05]), and increased burden of white matter hyperintensities (WMH) (P = 0.016). Among participants with diabetes, those with HbA_1c ≥7.0% had smaller total and regional brain volumes and an increased burden of WMH (all P < 0.05) compared with those with HbA_1c <7.0%. Similarly, participants with longer duration of diabetes (≥10 years) had smaller brain volumes and higher burden of lacunes (all P < 0.05) than those with a diabetes duration <10 years. We found no evidence for mediation by WMH in associations of diabetes with smaller brain volumes by structural equation models (all P > 0.05).

CONCLUSIONS

More-severe diabetes (defined by higher HbA_1c and longer disease duration) but not prediabetes or less-severe diabetes was associated with smaller brain volumes and an increased burden of brain vascular pathology. No evidence was found that associations of diabetes with smaller brain volumes are mediated by brain vascular pathology, suggesting that other mechanisms may be responsible for these associations.

Metabolic Syndrome is Associated with White Matter Hyperintensity in Stroke Patients

Some risk factors of stroke may play a role in white matter hyperintensity (WMH). Metabolic syndrome (MetS) is a recognised risk factor of stroke, but it is controversial whether MetS is also associated with WMH. We examined the association of MetS with the prevalence of WMH in acute stroke patients. We conducted a cross-sectional study in 246 acute ischemia stroke patients. The patients with acute stroke were clinically evaluated, including waistline circumference, blood pressure, glycaemia, serum triglyceride and high density lipoprotein cholesterol level. The degree of WMH was assessed by Fluid-attenuated inversion recovery (FLAIR) sequence of magnetic resonance imaging (MRI) scans. MetS was diagnosed using the criteria by the National Cholesterol Education Adult Treatment Panel III. MetS was the independent variable evaluated in Binary regression analyses. It is found that old age (>60 years old), MetS and smoking were significantly associated with WMH in univariate analysis (p < .05). Spearman rank correlation showed that old age and MetS are related to WMH (r = 0.18, p = .005 and r = 0.18, p = .004, respectively). Hypertension is weakly but not significantly associated with WMH in correlation analysis (r = 0.11, p = .08). In multiple regression analysis, age and MetS remained independently associated with WMH (OR = 7.6, 95% CI 0.2–0.7 and OR = 11.7, 95% CI 0.1–0.5). Hypertension and hyperglycaemia tend to be associated but not significantly with WMH (p = .07, p = .08). Other MetS components such as large waist circumference and dyslipidaemia showed no association with WMH. After adjustment for age, WMH is significantly associated with MetS in stroke patients. Hypertension and hyperglycaemia tend to associated but not significantly with WMH in stroke patients.

Oxytocin system dysfunction as a common mechanism underlying metabolic syndrome and psychiatric symptoms in schizophrenia and bipolar disorders

There is growing interest in using intranasal oxytocin (OT) to treat social dysfunction in schizophrenia and bipolar disorders (i.e., psychotic disorders). While OT treatment results have been mixed, emerging evidence suggests that OT system dysfunction may also play a role in the etiology of metabolic syndrome (MetS), which appears in one-third of individuals with psychotic disorders and associated with increased mortality. Here we examine the evidence for a potential role of the OT system in the shared risk for MetS and psychotic disorders, and its prospects for ameliorating MetS. Using several studies to demonstrate the overlapping neurobiological profiles of metabolic risk factors and psychiatric symptoms, we show that OT system dysfunction may be one common mechanism underlying MetS and psychotic disorders. Given the critical need to better understand metabolic dysregulation in these disorders, future OT trials assessing behavioural and cognitive outcomes should additionally include metabolic risk factor parameters.

Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes

The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients.A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume.Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P < 0.05; voxel threshold: 33). Gray matter volume in the right anterior cingulate was also negatively correlated with the preprandial serum glucose level gyrus in a voxel-dependent manner (r = -0.501; 2-tailed P = 0.001).The cingulo-temporal and insula gray matter alterations may be associated with the glucose dysregulation in prediabetic patients.

Components of Metabolic Syndrome and the Risk of Disability among the Elderly Population

The direct relationship between metabolic syndrome (MetS) and function disability has not been established. The aim of the present study was to investigate the relationship between MetS and functional disability in the elderly. This retrospective observational study included 1,778 participants aged 60–84 years from the National Health and Nutrition Examination Survey (1999–2002). Impairments in activities of daily living (ADL), instrumental activities of daily living (IADL), leisure and social activities (LSA), lower extremity mobility (LEM), and general physical activities (GPA) were assessed. Additionally, the associations between the features of MetS and disability were evaluated. MetS was associated with a high prevalence of functional dependence in ADL, IADL, LSA, LEM, and GPA. After adjusting for potential confounders, a high number of MetS components was found to be associated with increased disability (P = 0.002). Additionally, associations were observed between MetS components, including abdominal obesity and high triglycerides levels, and functional dependence in ADL, IADL, LSA, LEM, and GPA (all, P < 0.05). A linear increase in disability might be associated with the number of MetS components in an elderly population. Additionally, MetS abnormalities, particularly abdominal obesity and high triglycerides levels, might be highly predictive of functional dependence in the elderly.

Novel Molecular Mechanisms in the Development of Non-Alcoholic Steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in adults and children worldwide. NAFLD has become a severe health issue and it can progress towards a more severe form of the disease, the non-alcoholic steatohepatitis (NASH). A combination of environmental factors, host genetics, and gut microbiota leads to excessive accumulation of lipids in the liver (steatosis), which may result in lipotoxicity and trigger hepatocyte cell death, liver inflammation, fibrosis, and pathological angiogenesis. NASH can further progress towards liver cirrhosis and cancer. Over the last few years, cell-derived extracellular vesicles (EVs) have been identified as effective cell-to-cell messengers that transfer several bioactive molecules in target cells, modulating the pathogenesis and progression of NASH. In this review, we focused on recently highlighted aspects of molecular pathogenesis of NASH, mediated by EVs via their bioactive components. The studies included in this review summarize the state of art regarding the role of EVs during the progression of NASH and bring novel insight about the potential use of EVs for diagnosis and therapeutic strategies for patients with this disease.

Alterations of neocortico-limbic association fibers and correlation with diet in prediabetes diagnosed by impaired fasting glucose

PURPOSE

To assess the existence of alterations in the micro-integrity of the fasciculus in prediabetic subjects. The issue of micro-integrity in white matter tracts has not been adequately addressed in prediabetes.

MATERIALS AND METHODS

Sixty-four prediabetic subjects and 54 controls were enrolled. All participants completed 24-hour diet records and 3-day diet records and received diffusion tensor imaging at 3T. The data for white matter micro-integrity were analyzed and compared between prediabetic subjects and controls with age and gender as covariates. In addition, voxel-wise regression between white matter micro-integrity, diet, and preprandial glucose levels were used to explore the relationship between white matter micro-integrity and diet or serum glucose levels.

RESULTS

We found that prediabetic subjects had significant reductions in the micro-integrity of bilateral anterior thalamic radiation, left inferior longitudinal fasciculus, and left superior longitudinal fasciculus (corrected P < 0.05). In addition, total carbohydrate intake amount and preprandial serum glucose levels were negatively correlated with the micro-integrity in the left inferior longitudinal fasciculus and left anterior thalamic radiation (r: -0.47, corrected P < 0.05).

CONCLUSION

Restrictive alterations in the white matter micro-integrity of the anterior thalamic radiation and inferior and superior longitudinal fasciculi might represent the initial "hot spots" for white matter tract alterations, which might play a role in the development of prediabetes. J. Magn. Reson. Imaging 2016;43:1500-1506.

Impact of Nutrition on Cerebral Circulation and Cognition in the Metabolic Syndrome

The increasing prevalence of Metabolic Syndrome (MetS), defined as the clustering of abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, appears to be driving the global epidemics cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Nutrition has a major impact on MetS and plays an important role in the prevention, development, and treatment of its features. Structural and functional alterations in the vasculature, associated with MetS, might form the link between MetS and the increased risk of developing CVD and T2DM. Not only does the peripheral vasculature seem to be affected, but the syndrome has a profound impact on the cerebral circulation and thence brain structure as well. Furthermore, strong associations are shown with stroke, cognitive impairment, and dementia. In this review the impact of nutrition on the individual components of MetS, the effects of MetS on peripheral and cerebral vasculature, and its consequences for brain structure and function will be discussed.

Subclinical Atherosclerosis Is Inversely Associated With Gray Matter Volume in African Americans With Type 2 Diabetes

OBJECTIVE

Relative to European Americans, African Americans manifest lower levels of computed tomography-based calcified atherosclerotic plaque (CP), a measure of subclinical cardiovascular disease (CVD). Potential relationships between CP and cerebral structure are poorly defined in the African American population. We assessed associations among glycemic control, inflammation, and CP with cerebral structure on MRI and with cognitive performance in 268 high-risk African Americans with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Associations among hemoglobin A1c (HbA1c), C-reactive protein (CRP), and CP in coronary arteries, carotid arteries, and the aorta with MRI volumetric analysis (white matter volume, gray matter volume [GMV], cerebrospinal fluid volume, and white matter lesion volume) were assessed using generalized linear models adjusted for age, sex, African ancestry proportion, smoking, BMI, use of statins, HbA1c, hypertension, and prior CVD.

RESULTS

Participants were 63.4% female with mean (SD) age of 59.8 years (9.2), diabetes duration of 14.5 years (7.6), HbA1c of 7.95% (1.9), estimated glomerular filtration rate of 86.6 mL/min/1.73 m(2) (24.6), and coronary artery CP mass score of 215 mg (502). In fully adjusted models, GMV was inversely associated with coronary artery CP (parameter estimate [β] -0.47 [SE 0.15], P = 0.002; carotid artery CP (β -1.92 [SE 0.62], P = 0.002; and aorta CP [β -0.10 [SE 0.03] P = 0.002), whereas HbA1c and CRP did not associate with cerebral volumes. Coronary artery CP also associated with poorer global cognitive function on the Montreal Cognitive Assessment.

CONCLUSIONS

Subclinical atherosclerosis was associated with smaller GMV and poorer cognitive performance in African Americans with diabetes. Cardioprotective strategies could preserve GMV and cognitive function in high-risk African Americans with diabetes.

Severity of non-alcoholic fatty liver disease is associated with high systemic levels of tumor necrosis factor alpha and low serum interleukin 10 in morbidly obese patients

Morbid obesity has been shown to increase the risk to develop hepatic steatosis, also referred to as non-alcoholic fatty liver disease (NAFLD). Emerging evidence suggests that the severity of NAFLD may associate with increased serum levels of inflammatory markers as well as decreased concentration of mediators with anti-inflammatory actions, such as tumor necrosis factor alpha (TNF-α) and interleukin (IL) 10, respectively. We thus examined the serum levels of TNF-α and IL-10 in 102 morbidly obese women and men (body mass index > 40 kg/m(2)), exhibiting different grades of NAFLD. Blood glucose, glycated hemoglobin, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), total cholesterol, triglycerides, high- and low-density lipoproteins, parameters of liver function, TNF-α, and IL-10 were measured in each subject. The stage of NAFLD was estimated by abdominal ultrasound imaging. In comparison with morbidly obese subjects without steatosis, morbidly obese patients with NAFLD showed increased age (39.23 ± 9.80 years), HOMA-IR (6.74 ± 1.62), total cholesterol (219.7 ± 9.58 mg/dl), aspartate aminotransferase (36.25 ± 3.24 UI/l), gamma-glutamyl transpeptidase (37.12 ± 3.41 UI/l), and TNF-α (37.41 ± 1.72 pg/ml) as well as decreased serum levels of IL-10 (61.05 ± 2.43 pg/ml). Interestingly, the systemic levels of TNF-α increased, while IL-10 decreased in accordance with the severity of NAFLD, which supports a role for systemic inflammatory mediators in promoting steatosis progression. Further clinical prospective studies need to be addressed to elucidate the role of TNF-α and IL-10 in the development of NAFLD while also establishing their clinical utility in the assessment of morbidly obese patients at higher risk to develop severe steatosis.

Obesity: cerebral damage in obesity-associated metabolic syndrome

The prevalence of the metabolic syndrome has increased in tandem with that of obesity. The metabolic syndrome is associated with structural and functional cerebral damage. A new study confirms the association between the metabolic syndrome and reduced brain volume in the absence of diabetes mellitus. Here, we highlight how vascular dysfunction potentially contributes to this brain damage.