The Picture Interpretation Test 360°: A Virtual Reality Screening Tool for Executive Dysfunction and Rehabilitation Stratification in Mild Cognitive Impairment

Event Abstract Back to Event Τhe pattern of relations between cognitive control and Theory of Mind in older adults having vascular risk factors and older adults with Mild Cognitive Impairment: are there any differences? Glykeria Tsentidou1*, Despoina Moraitou1, Elvira Masoura1 and Georgia Papantoniou2 1 Aristotle University of Thessaloniki, Greece 2 University of Ioannina, Greece Aim: The study aims at investigating the relationships among cognitive control (Cc) and Theory of Mind (ToM) in older adults experiencing very mild cognitive decline due to risk factors for vascular disease development (VRF), and older adults with Mild Cognitive Impairment (MCI). Method: The two groups (VRF, MCI) matched for gender, age, and educational level, are measured with tests assessing different dimensions of Cc and ToM. Results: Non-recursive and multi-group path analyses will be applied to the data, to find the relationships between Cc and ToM, for each group, and to reveal possible differences. Conclusion: A different pattern of relationships between ToM and Cc in each group would emerge, as a possible result of the progression of cognitive decline which may lead to a reconfiguration of the relations between these dimensions, due to the efforts of the cognitive system to adapt to the diminishing levels of brain functioning. Recently, several studies have linked non-diagnosed vascular pathology with cognitive impairment. It is reasonable to maintain that since vascular disease affects the brain, it also affects cognitive functioning (Lindeboom, Weinstein, 2004) and leads to some type of "cognitive frailty". Indeed, the theoretical approach of the "vascular hypothesis of cognitive aging" (Anstey, 2008; Spiro, Brady, 2008) posits that basic risk factors for the emergence of vascular disease, such as hypertension, hyperlipidemia, and diabetes mellitus, affect cognitive functions that are supported by the frontal brain regions (Elias, Elias, D'Agostino, et al., 2005; Okusaga, Stewart, Butcher, et al., 2012). A step further in regards to cognitive decline, the term "Mild Cognitive Impairment (MCI)" was introduced to describe the trajectory of decline in cognition that is identified with dementia (Zheng, Sun, Dong, et al., 2014). Besides the well established memory deficits, many patients with MCI deal with problems in executive functions or cognitive control processes (Cc), namely, the higher-order cognitive processes that control thought and action (Ready, Ott, Grace, & Cahn-Weiner, 2003; Marshall, Rentz, Frey, Locascio, Johnson, Sperling, 2011; Mitchell & Shiri-Feshki M, 2009). In the more recent literature, we come across studies on Theory of Mind (ToM) in MCI. ToM is the most known dimension of social cognition that refers to the ability to understand other people's intentions, beliefs, and desires. What is known till now is that, compared to cognitively healthy older adults, MCI patients seem to perform worse on complex ToM tasks. However, to our knowledge, there is not sufficient evidence regarding the pattern of the relationships between Cc and ToM in community dweller older adults having vascular risk factors (VRF group), and MCI patients. In this light, the present study aims to investigate the differences of older adults having vascular risk factors and MCI patients in regards to the pattern of the relations between cognitive control and Theory of Mind. The following hypothesis has been formulated: the pattern of the relations between Cc and ToM is expected to be more complex in MCI patients, compared to VRF group, given a possible increased recruitment of Cc, in order to complete a task, that MCI patients may follow as a compensatory mechanism against their more advanced level of cognitive decline. The sample consists of two groups of older adults, matched for gender, age and educational level. Each group is composed of 30 participants. All participants are at least 60 years old, with at least six years of schooling and Hellenic as their native language. The first group is composed of community dweller older adults having vascular risk factors (VRF), and the other of older adults diagnosed with MCI. All participants are informed about the procedure and the aim of the study, and their written consent is taken. The neuropsychological assessment is implemented with the administration of a battery of tests measuring Cc as inhibitory control, task switching, updating-monitoring, and planning, and assessing ToM as social mental verb understanding and indirect speech perception. Emotion recognition ability is also assessed, as an underlying construct for the development of ToM. The neuropsychological evaluation takes place over two sessions due to its long duration. The order in which the tests are administered to each participant differs, to avoid serial position effects. Assessment procedure is in progress and soon will be completed. In order to reveal differences in the pattern of relations among the different tasks, structural equation modeling (SEM) techniques will be conducted: using non-recursive path modeling, the direction of the relations between Cc and ToM would be revealed (Kline, 2005). Next, a series of multi-group path analyses will be performed to trace and compare any differentiated patterns of relations among variables (Kline, 2005), for each group. A different pattern of relationships between ToM and Cc in VRF and MCI groups would emerge. Specifically, MCI patients would display a more complex pattern of associations among Cc and ToM dimensions, compared to VRF group, as a possible result of the progression of cognitive decline which may lead to a reconfiguration of the relations between these dimensions, due to the effort of the cognitive system to adapt to the diminishing levels of brain functioning. If there wouldn't be any significant differences in Cc and ToM performance of the two groups, this might lead to the conclusion that the progression of mild cognitive decline in older adults may be reflected in a more complex pattern of associations among cognitive constructs. References Anstey, K. (2008). Cognitive aging and functional biomarkers. In S. Hofer and D. Alwin Eds. Handbook of cognitive aging: interdisciplinary perspectives Thousand Oaks, California: Sage;327 . Elias, P., Elias, MF., D'Agostino, RB., et al. (2005). Serum cholesterol and cognitive performance in the Framingham Heart Study. J Biobehavioral Medical; 67(1): 24-30. Kline, RB. (2005). Principles and practice of structural equation modeling; New York: Guilford Press Lindeboom, J., Weinstein, H. (2004). Neuropsychology of cognitive ageing, minimal cognitive impairment, Alzheimer's disease, and vascular cognitive impairment. European Journal of Pharmacology; 490: 83–6. Marshall, A., Rentz, M., Frey, T., Locascio, J., Johnson, A., Sperling, A. (2011).Executive function and instrumental activities of daily living in mild cognitive impairment and Alzheimer's disease. Alzheimer's & Dementia, 7, 300 - 308. Mitchell, J. & Shiri-Feshki, M. (2009). Rate of progression of mild cognitive impairment to dementia meta-analysis of 41 robust inception cohort studies. Acta Psychiatrica Scandinavica, 119 (4), 252–265. Okusaga, Ο., Stewart, ΜCW., Butcher, I., et al. (2012). Smoking, hypercholesterolaemia and hypertension as risk factors for cognitive impairment in older adults. Age Ageing; 42(3): 306-11. Ready, E., Ott, R., Grace, J., & Cahn-Weiner, A. (2003). Apathy and executive dysfunction in mild cognitive impairment and Alzheimer disease. American Journal of Geriatric Psychiatry, 11(2), 222–228. Spiro, A., Brady, C. (2008). Integrating health into cognitive aging research and theory. In S. Hofer and D. Alwin Eds. Handbook of cognitive aging: interdisciplinary perspectives Thousand Oaks, California: Sage: 260-83. Zheng, D., Sun, H., Dong, X., Liu, B., Xu, Y., Chen, S., Song, L., Zhang, H., Wang, X. (2014). Executive dysfunction and gray matter atrophy in amnestic mild cognitive impairment. Neurobiology of Aging, 35, 548 - 555. Keywords: vascular risk factors, Mild Cognitive Impairment, cognitive control, Theory of Mind, neuropsychological assessment Conference: SAN2016 Meeting, Corfu, Greece, 6 Oct - 9 Oct, 2016. Presentation Type: Poster Presentation in SAN2016 Conference Topic: Posters Citation: Tsentidou G, Moraitou D, Masoura E and Papantoniou G (2016). Τhe pattern of relations between cognitive control and Theory of Mind in older adults having vascular risk factors and older adults with Mild Cognitive Impairment: are there any differences?. Conference Abstract: SAN2016 Meeting. doi: 10.3389/conf.fnhum.2016.220.00123 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers' terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Jul 2016; Published Online: 01 Aug 2016. * Correspondence: Mrs. Glykeria Tsentidou, Aristotle University of Thessaloniki, Thessaloniki, Greece, gltsentidou@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Glykeria Tsentidou Despoina Moraitou Elvira Masoura Georgia Papantoniou Google Glykeria Tsentidou Despoina Moraitou Elvira Masoura Georgia Papantoniou Google Scholar Glykeria Tsentidou Despoina Moraitou Elvira Masoura Georgia Papantoniou PubMed Glykeria Tsentidou Despoina Moraitou Elvira Masoura Georgia Papantoniou Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Executive function impairment, a slight but noticeable cognitive deficit in mild cognitive impairment (MCI) patients, is influenced by gamma-aminobutyric acid (GABA) levels. Reduced cognitive function is accompanied by thinning of the cerebral cortex, which has higher GABA levels than white matter. However, the relationships among GABA levels, cortical thickness, and executive function in MCI patients have not yet been elucidated. We investigated the relationships among GABA levels, cortical thickness, and executive function in MCI patients. In this study, a total of 36 MCI patients and 36 sex-, age-, and education-matched healthy controls (HC) were recruited. But 33 MCI patients and 35 HC were included because of head motion or poor data quality for three MCI patients and one HC. The levels of gamma-aminobutyric acid plus relative to creatine (GABA+/Cr) and glutamate-glutamine relative to creatine (Glx/Cr) in the anterior cingulate cortex (ACC) and posterior cingulate cortex (PCC) were measured using the Meshcher-Garwood point resolved spectroscopy (MEGA-PRESS) sequence. Metabolite ratios, cortical thickness, and executive function and their interrelationships were determined in the MCI and HC groups. Patients with MCI showed lower GABA+/Cr levels in the ACC and PCC. Combined levels of GABA+ and Glx in the ACC and GABA+ in the PCC showed good diagnostic efficacy for MCI (AUC: 0.82). But no differences in cortical thickness were found between the two groups. In the MCI group, lower GABA+/Cr level was correlated to worse performance on the digit span test backward, and the shape trail test-B. The cortical thickness was not associated with GABA+ levels and executive function in patients. These results implied that decreased GABA levels in the ACC and PCC had a critical role in the early diagnosis of impaired executive function of MCI. Therefore, GABA in the ACC and PCC could be a potential diagnostic marker of the executive function decline of MCI.

High Activities of BACE1 in Brains with Mild Cognitive Impairment

Unravelling Neuroinflammation-Mediated Mitochondrial Dysfunction in Mild Cognitive Impairment: Insights from Targeted Metabolomics

AimWhite matter hyperintensities (WMH) obtained by magnetic resonance imaging (MRI) have been reported to promote neurodegeneration and cognitive decline in patients with mild cognitive impairment (MCI). However, little is known about the association between regional WMH (rWMH) and cognitive dysfunction in MCI. We hence investigated the associations between rWMH volumes and cognitive dysfunction in MCI.MethodsThirty‐eight subjects with amnestic MCI were analysed. The volumes of periventricular hyperintensities (PVH) and deep WMH (DWMH) were measured on a T2‐FLAIR MRI using a 3D‐slicer, and regional PVH and DWMH (rPVH and rDWMH) volumes were calculated. The associations of rPVH and rDWMH volumes with cognition and blood levels of various molecules were investigated. Furthermore, rPVH and rDWMH volumes were compared between MCI with vascular risk factors, such as hypertension, diabetes mellitus (DM), and dyslipidemia, and those without these risk factors.ResultsrPVH volume (bilateral cornu frontale, pars parietalis, and cornu occipitale) positively correlated with Trail Making Test‐A/B scores and CysC level, whereas rDWMH volume did not correlate with any of the items. rPVH volumes (right cornu frontale, bilateral pars parietalis and cornu occipitale, and right pars temporalis) and rDWMH volumes (left frontal and parietal lobes) were significantly larger in MCI patients with DM than in those without.ConclusionsPVH volumes (bilateral areas of cornu frontale, pars parietalis, and cornu occipitale) were closely associated with attention and executive dysfunction. Serum CysC level and DM were associated with WMH volume, suggesting that CysC level and DM might be important markers for determining treatment strategies for white matter abnormalities in MCI. Geriatr Gerontol Int 2021; 21: 644–650.

The pattern of cortical thickness associated with executive dysfunction in MCI and SCC: The MEMENTO cohort

Vascular risk factors and intensity of cognitive dysfunction in MCI

The subjective experience of self-awareness is attributed to the human capacity for introspective thought during periods of mind-wandering. However, how this cognitive function is impacted in individuals with mild cognitive impairment (MCI) still needs to be better understood. To address this gap, we investigated alterations in self-referential thinking in a cohort of 30 MCI patients, comparing them to 60 healthy old-aged and 60 healthy younger controls. MCI patients exhibited a notable decline in overall cognitive function, as evidenced by significantly lower scores on the Montreal Cognitive Assessment (MoCA), with particular deficits in Memory subscore and Memory Index Score (MIS). Employing the Amsterdam Resting-State Questionnaire (ARSQ) to assess mind-wandering, we observed diminished self-related thoughts relating to personal past experiences and future thinking among MCI patients. Notably, using high-density electroencephalography (hdEEG) microstate analysis, we detected reduced neural activity for microstate C associated with self-related thoughts in MCI patients and healthy older relative to healthy younger controls, and an increase in neural activity for microstate A in MCI patients compared to healthy older and younger controls. This aberrant temporal activity was localized within brain regions implicated in episodic autobiographical memory and the default mode network. Our results highlight a link between impaired mind-wandering ability and dysfunction within the intrinsic neural networks of MCI patients, underscoring its implications for disruptions in the sense of self within this clinical population.

Objective: To analyze the influencing factors of type 2 diabetes mellitus (T2DM) patients with mild cognitive impairment (MCI), and to explore the association between plasma osteopontin (OPN) levels and MCI. Methods: A retrospective analysis was conducted on the clinical data of 254 patients with T2DM admitted to Zhongda Hospital Affiliated to Southeast University from October 2021 to May 2023. The patients were divided into MCI group (n=106) and normal cognitive function control group (n=148) according to whether they had MCI. Clinical data were collected, cognitive function was assessed using neurological scales and plasma OPN levels were measured by enzyme linked immunosorbent assay. A multivariate logistic regression model was applied to analyze the influencing factors of MCI in T2DM patients. Interaction terms between gender, age, body mass index (BMI), and OPN were established to verify their significance levels. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive value of OPN for MCI in T2DM patients. The mediation model of OPN-FPG-montreal cognitive assessment(MoCA) was constructed with fasting plasma glucose (FPG) as the mediating variable to test the mediating effect, and the mediating effect percentage was calculated. Results: A total of 254 patients were included, including 162 males and 92 females, with an average age of (61.5±7.5) years old. Compared with the control group, the patients in MCI group were older[63.0(59.0, 69.0) years vs 60.0(54.2, 66.8) years], had a greater proportion of females [(43.4%(46/106) vs 31.1%(46/148)], shorter years of education[12(9, 12) years vs 12(9,15) years], longer duration of diabetes[15.0(8.0, 20.0) years vs 10.0(5.0, 15.0) years], and higher levels of FPG[7.78(6.07, 10.23) mmol/L vs 6.86(5.36, 8.59) mmol/L], insulin resistance index[2.93(2.47, 3.98) vs 2.79(2.27, 3.25)], glycated hemoglobin (HbA1c) [9.24%(7.89%, 10.96%) vs 7.97%(7.00%, 9.45%)], total cholesterol(TC)[(4.51±1.17) mmol/L vs (4.19±0.99) mmol/L], and OPN [11.30(8.68, 12.84) ng/ml vs 9.69(7.82, 11.74) ng/ml] (all P<0.05). The scores of various neuropsychological tests in MCI patients were lower than those in control group with normal cognitive function (all P<0.05). Spearman correlation analysis showed that age(r=-0.212), duration of diabetes mellitus(r=-0.156), duration of hypertension(r=-0.132), FPG(r=-0.207), insulin resistance index(r=-0.171), HbA1c(r=-0.271), OPN(r=-0.238), and total cholesterol (r=-0.125) were negatively correlated with MoCA scores, whereas years of education(r=0.285) were positively correlated with MoCA scores(all P<0.05). Multifactorial logistic regression analysis showed that age, years of education, duration of diabetes mellitus, HbA1c, TC and OPN levels were the influencing factors of T2DM patients with MCI, and the risk of MCI increased by 15% for every 1 ng/ml increase in OPN (OR=1.15, 95%CI: 1.021-1.295, P=0.021), and the relationship was not affected by age, gender and BMI(The interaction effects are all P>0.05). The area under the curve (AUC) of the working curve of subjects with OPN predicting combined MCI in patients with T2DM was 0.612 (95%CI: 0.541-0.682), and the AUC was 0.702 (95%CI: 0.638-0.767) after the combination of HbA1c and OPN. The results of the mediated effect model showed that FPG partially mediated the correlation between OPN and MoCA in T2DM patients, and the mediated effect accounted for 11.34% of the total effect. Conclusions: Plasma OPN level is associated with MCI in patients with T2DM,and the higher the OPN level, the higher the risk of T2DM patients developing MCI.

Objective: To analyze the clinical characteristics of patients with common cardiovascular diseases (CVD, including hypertension, coronary heart disease, atrial fibrillation, and heart failure) combined with mild cognitive impairment (MCI) and explore the potential risk factors of MCI in patients with CVD. Methods: A total of 2 294 patients with common cardiovascular diseases who met the criteria at Cardiology Medical Center in Beijing Anzhen Hospital, Capital Medical University, from June 1, 2021, to January 5, 2022, were retrospectively included. The patients were divided into the normal cognitive function group (1 107 cases) and the MCI group (1 187 cases). Demographic information and CVD status were collected. The information of cognitive function were collected using the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) scales. The difference between normal cognitive function and MCI were compared and analyzed. The logistic regression analysis was used to explored risk factors of MCI in CVD patients. Results: A total of 2 294 patients aged (60.6±10.4) years were included, among whom there were 29.99% (688 cases) females. Compared with patients in the normal cognitive function group, patients in the MCI group were older [ (57.9±11.4) vs (63.1±8.9) years old, P<0.001], with a higher proportion of women [26.47% (293 cases) vs 33.28% (395 cases), P<0.001]; there was a higher proportion of patients suffering from hypertension in the MCI group [59.62% (660 cases) vs 64.62% (767 cases), P=0.014］, and more components of CVD [(1.68±0.62) vs (1.74±0.65) components, P=0.017]. The risk factors of MCI in patients with common CVD were increased age, increased depression score, combined with hypertension, and ≥3 common components of CVD, with OR (95%CI) of 1.043 (1.032-1.054), 1.021 (1.004-1.037), 1.151 (1.142-3.439), and 1.137 (1.023-1.797), respectively (all P values <0.05). Increasing education level was observed to be associated with reduced risk of MCI with OR (95%CI) of 0.319 (0.271-0.378) (P<0.05). Conclusions: The incidence of MCI was high in CVD patients. The risk factors of MCI in CVD patients included hypertension and≥3 common components of CVD.

Objective To investigate platelet α and β secretase activities and the amounts of platelet soluble fragment of APP (sAPPα) produced by α-secretase in patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Methods The neurological functions of 48 non-demented patients, 42 MCI and 40 AD patients were evaluated by neuropsychological examinations. The platelet α and β secretase activities and sAPPα production in each group were measured by fluorescence and Western blotting analysis respectively. Results The α secretase activities in non-demented, MCI and AD group were 100.0%±10.6%, 78.2%±9.4% and 61.8%±7.2% respectively. As compared with non-demented group, the α secretase activities in MCI and AD group were decreased (F=22.935, P=0.001). The α secretase activity in AD group was significantly lower than MCI group. The β secretase activities in non-demented, MCI and AD group were 100.0%±11.2%, 145.8%±12.7% and 189.8%±14.2% respectively. The β secretase activities in MCI and AD group were significantly higher than that in non-demented group (F=16.368, P=0.001). The β secretase activity in AD group was significantly decreased as compared with MCI group. The sAPPα amounts in MCI group and AD group were all decreased as compared with that in control group; the sAPPα amount in AD patients was significantly decreased as compared with that in MCI group. Conclusions The platelet α secretase activity and its production sAPPα in MCI and AD patients are decreased, while β secretase activity is increased, as compared with that in control group; the altered α and β secretase activities may participate in the pathogenesis of MCI and AD patients and may have diagnostic potential for them. Key words: Cognition disorders; Alzheimer disease; Amyloid precursor protein secretases

It has been suggested that mild cognitive impairment (MCI) patients deteriorate faster than the healthy elderly population and have an increased risk of developing dementia. Certain blood molecular biomarkers have been identified as prognostic markers in Alzheimer's disease (AD). The present study was aimed to assess the status of the platelet amyloid precursor protein (APP) metabolism in MCI and AD subjects and establish to what extent any variation could have a prognostic value suggestive of predictive AD in MCI patients. Thirty-four subjects diagnosed with MCI and 45 subjects with AD were compared to 28 healthy elderly individuals for assessing for protein levels of APP, β-APP cleaving enzyme 1 (BACE1), presenilin 1 (PS1) and a disintegrin and metalloproteinase-10 (ADAM-10) by western blot, and for the enzyme activities of BACE1 and γ-secretase by using specific fluorogenic substrates, in samples of platelets. A similar pattern in the healthy elderly and MCI patients was found for BACE1 and PS1 levels. A reduction of APP levels in MCI and AD patients compared with healthy elderly individuals was found. Augmented levels of ADAM-10 in both MCI and AD were displayed in comparison with age-matched control subjects. The ratio ADAM-10/BACE1 was higher for the MCI group versus AD group. Whereas BACE1 and PS1 levels were only increased in AD regarding to controls, BACE1 and γ-secretase activities augmented significantly in both MCI and AD groups. Finally, differences and similarities between MCI and AD patients were observed in several markers of platelet APP processing. Larger sample sets from diverse populations need to be analyzed to define a signature for the presence of MCI or AD pathology and to early detect AD at the MCI stage.

ObjectiveThe aim of this study was to investigate the clinical effects of insulin resistance (IR) in the development of mild cognitive impairment (MCI) in elderly adults with Type 2 diabetes mellitus (T2DM).MethodsSeventy-eight patients with T2DM were recruited and divided into MCI group (<26, n=48) and normal group (≥26, n=30) according to the Montreal Cognitive Assessment (MoCA) score. The fasting plasma glucose (FPG), HbA1c, and fasting plasma C-peptide (FPC) were examined and compared between the two groups. The Pancreatic islets function (HOMA-islet) and Insulin Resistance Index (HOMA-IR) were also calculated for the two groups. Using the HOMA-IR and HOMA-islet as the reference, the predicted values for MCI in T2DM patients were calculated by sensitivity, specificity and area under the receiver operating characteristic (ROC) curve.ResultsThe MoCA scores were statistically different between the MCI and control groups (23.79±1.15 vs 28.50±1.01, p<0.05). The serum FPG and FPC were 10.38±2.36 mmol/L and 0.79±0.34 ng/mL in the MCI group which were significant different from those of the control group (8.96±2.55 mmol/L and 1.04±0.38 ng/mL; p<0.05). The HOMA-IR and HOMA-islet were 10.08±2.64 and 94.67±29.12 for the MCI group and 8.16±2.46 and 130.30±38.43 for the control group; both were statistically different (p<0.05). The serum HbA1c was 11.02±2.59% and 9.37±2.00% for the MCI and control groups (significantly different with p<0.5). A significant positive correlation was found between MoCA score and HOMA-islet (rpearson=0.44; p<0.001). A significant negative correlation existed between MoCA score and serum HbA1c (r=-0.25; p=0.03). The areas under the ROC curve were 0.70 (0.57~0.82), 0.69 (0.57~0.81), 0.69 (0.57~0.80), 0.72 (0.60~0.84), 0.72 (0.60~0.84) and 0.76 (0.65~0.88) respectively for FPG, FPC, HbA1c, HOMA-IR and HOMA-islet.ConclusionInsulin resistance is a risk factor for mild cognitive impairment and can be a biomarker for prediction of MCI in patients with T2DM.

Most of the previous task functional magnetic resonance imaging (fMRI) studies found abnormalities in distributed brain regions in mild cognitive impairment (MCI) and Alzheimer's disease (AD), and few studies investigated the brain network dysfunction from the system level. In this meta-analysis, we aimed to examine brain network dysfunction in MCI and AD. We systematically searched task-based fMRI studies in MCI and AD published between January 1990 and January 2014. Activation likelihood estimation meta-analyses were conducted to compare the significant group differences in brain activation, the significant voxels were overlaid onto seven referenced neuronal cortical networks derived from the resting-state fMRI data of 1,000 healthy participants. Thirty-nine task-based fMRI studies (697 MCI patients and 628 healthy controls) were included in MCI-related meta-analysis while 36 task-based fMRI studies (421 AD patients and 512 healthy controls) were included in AD-related meta-analysis. The meta-analytic results revealed that MCI and AD showed abnormal regional brain activation as well as large-scale brain networks. MCI patients showed hypoactivation in default, frontoparietal, and visual networks relative to healthy controls, whereas AD-related hypoactivation mainly located in visual, default, and ventral attention networks relative to healthy controls. Both MCI-related and AD-related hyperactivation fell in frontoparietal, ventral attention, default, and somatomotor networks relative to healthy controls. MCI and AD presented different pathological while shared similar compensatory large-scale networks in fulfilling the cognitive tasks. These system-level findings are helpful to link the fundamental declines of cognitive tasks to brain networks in MCI and AD.

Increased serum levels of cyclophilin a and matrix metalloproteinase-9 are associated with cognitive impairment in patients with obstructive sleep apnea