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Moran C, Beare R, Phan TG, Bruce DG, Callisaya ML, Srikanth V. Type 2 diabetes mellitus and biomarkers of neurodegeneration. Neurology 2015; 85:1123-30. [PMID: 26333802 DOI: 10.1212/wnl.0000000000001982] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 06/03/2015] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Our objective was to investigate whether type 2 diabetes mellitus (T2DM) influences neurodegeneration in a manner similar to Alzheimer disease (AD), by promoting brain β-amyloid (Aβ) or tau. METHODS We studied the cross-sectional associations of T2DM with cortical thickness, brain Aβ load, and CSF levels of Aβ and tau in a sample of people from the Alzheimer's Disease Neuroimaging Initiative with diagnoses of AD dementia, mild cognitive impairment, and normal cognition. All (n=816) received MRI, and a subsample underwent brain amyloid imaging (n=102) and CSF Aβ and tau measurements (n=415). Analyses were performed across and within cognitive diagnostic strata. RESULTS There were 124 people with T2DM (mean age 75.5 years) and 692 without T2DM (mean age 74.1 years). After adjusting for age, sex, total intracranial volume, APO ε4 status, and cognitive diagnosis, T2DM was associated with lower bilateral frontal and parietal cortical thickness (mL) (β=-0.03, p=0.01). T2DM was not associated with 11C Pittsburgh compound B standardized uptake value ratio (AU) in any brain region or with CSF Aβ42 levels (pg/mL). T2DM was associated with greater CSF total tau (pg/mL) (β=16.06, p=0.04) and phosphorylated tau (β=5.84, p=0.02). The association between T2DM and cortical thickness was attenuated by 15% by the inclusion of phosphorylated tau. CONCLUSIONS T2DM may promote neurodegeneration independent of AD dementia diagnosis, and its effect may be driven by tau phosphorylation. The mechanisms through which T2DM may promote tau phosphorylation deserve further study.
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Affiliation(s)
- Chris Moran
- From the Stroke and Ageing Research Group (C.M., T.G.P., V.S.), Vascular Brain Ageing Division, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne; Neurosciences (C.M., T.G.P., V.S.), Monash Medical Centre, Monash Health, Melbourne; Caulfield General Medical Centre (C.M.), Alfred Health, Melbourne; Developmental Imaging (R.B.), Murdoch Children's Research Institute, Melbourne; School of Medicine and Pharmacology (D.G.B.), Fremantle Hospital, University of Western Australia; and Menzies Research Institute Tasmania (M.L.C., V.S.), University of Tasmania, Hobart, Australia
| | - Richard Beare
- From the Stroke and Ageing Research Group (C.M., T.G.P., V.S.), Vascular Brain Ageing Division, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne; Neurosciences (C.M., T.G.P., V.S.), Monash Medical Centre, Monash Health, Melbourne; Caulfield General Medical Centre (C.M.), Alfred Health, Melbourne; Developmental Imaging (R.B.), Murdoch Children's Research Institute, Melbourne; School of Medicine and Pharmacology (D.G.B.), Fremantle Hospital, University of Western Australia; and Menzies Research Institute Tasmania (M.L.C., V.S.), University of Tasmania, Hobart, Australia
| | - Thanh G Phan
- From the Stroke and Ageing Research Group (C.M., T.G.P., V.S.), Vascular Brain Ageing Division, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne; Neurosciences (C.M., T.G.P., V.S.), Monash Medical Centre, Monash Health, Melbourne; Caulfield General Medical Centre (C.M.), Alfred Health, Melbourne; Developmental Imaging (R.B.), Murdoch Children's Research Institute, Melbourne; School of Medicine and Pharmacology (D.G.B.), Fremantle Hospital, University of Western Australia; and Menzies Research Institute Tasmania (M.L.C., V.S.), University of Tasmania, Hobart, Australia
| | - David G Bruce
- From the Stroke and Ageing Research Group (C.M., T.G.P., V.S.), Vascular Brain Ageing Division, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne; Neurosciences (C.M., T.G.P., V.S.), Monash Medical Centre, Monash Health, Melbourne; Caulfield General Medical Centre (C.M.), Alfred Health, Melbourne; Developmental Imaging (R.B.), Murdoch Children's Research Institute, Melbourne; School of Medicine and Pharmacology (D.G.B.), Fremantle Hospital, University of Western Australia; and Menzies Research Institute Tasmania (M.L.C., V.S.), University of Tasmania, Hobart, Australia
| | - Michele L Callisaya
- From the Stroke and Ageing Research Group (C.M., T.G.P., V.S.), Vascular Brain Ageing Division, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne; Neurosciences (C.M., T.G.P., V.S.), Monash Medical Centre, Monash Health, Melbourne; Caulfield General Medical Centre (C.M.), Alfred Health, Melbourne; Developmental Imaging (R.B.), Murdoch Children's Research Institute, Melbourne; School of Medicine and Pharmacology (D.G.B.), Fremantle Hospital, University of Western Australia; and Menzies Research Institute Tasmania (M.L.C., V.S.), University of Tasmania, Hobart, Australia
| | - Velandai Srikanth
- From the Stroke and Ageing Research Group (C.M., T.G.P., V.S.), Vascular Brain Ageing Division, Department of Medicine, School of Clinical Sciences, Monash University, Melbourne; Neurosciences (C.M., T.G.P., V.S.), Monash Medical Centre, Monash Health, Melbourne; Caulfield General Medical Centre (C.M.), Alfred Health, Melbourne; Developmental Imaging (R.B.), Murdoch Children's Research Institute, Melbourne; School of Medicine and Pharmacology (D.G.B.), Fremantle Hospital, University of Western Australia; and Menzies Research Institute Tasmania (M.L.C., V.S.), University of Tasmania, Hobart, Australia.
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Djukic M, Wedekind D, Franz A, Gremke M, Nau R. Frequency of dementia syndromes with a potentially treatable cause in geriatric in-patients: analysis of a 1-year interval. Eur Arch Psychiatry Clin Neurosci 2015; 265:429-38. [PMID: 25716929 DOI: 10.1007/s00406-015-0583-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 02/08/2015] [Indexed: 01/10/2023]
Abstract
In addition to neurodegenerative and vascular causes of dementia, in the differential diagnosis potentially reversible conditions of dementia also must be assessed. Routine laboratory parameters and neuroimaging, which are recommended for the differential diagnosis of suspected dementia by the German S3 Guideline "Dementia", were retrospectively studied in 166 geriatric patients with suspected dementia. Delirium was diagnosed in six patients (3.6%). These six patients were excluded from the study. Of the 160 remaining patients, there were 99 (59.6%) with an already known dementia. In this subgroup of patients, we found a potentially treatable cause of dementia in 18.2%. In the remaining 61 patients (36.8%), the newly diagnosed dementia syndrome was established according to ICD-10 criteria. Potentially reversible causes of the dementia syndrome were found in 19 of these patients (31.1%). The most common cause was depressive pseudodementia in eight patients followed by vitamin B12 deficiency in six patients. A significant amount of our patients showed laboratory or imaging changes suggestive of potentially reversible causes of the dementia syndrome upon admission. The results of our study indicate the importance of careful differential diagnosis of dementia based on the recommendations of guidelines. Although therapy of these potential causes is not always accompanied by a full recovery, the identification and therapy of treatable causes of cognitive deficits are possible even for general practitioners, who often are the primary contact persons of affected individuals.
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Affiliation(s)
- Marija Djukic
- Department of Neuropathology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany,
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153
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Abstract
OBJECTIVE To examine the extent to which Type 2 diabetes mellitus (T2DM) is associated with impairments in executive function (EF). METHODS Medline, PsychoInfo, and Scopus databases and published references were used to identify articles examining the association between T2DM status (case versus control) and EF decrements. Results from studies were converted to standardized mean differences and compared using random-effects models. Moderator analysis was conducted for age, sex, and diabetes duration using maximum likelihood estimation. RESULTS Sixty studies (59 articles) including 9815 individuals with T2DM and 69,254 controls were included. Findings indicated a small but reliable association between T2DM status and EF decrements (d = -0.248, p < .001), observed across all aspects of EF examined: verbal fluency, mental flexibility, inhibition, working memory, and attention. Disease duration significantly moderated the effect of T2DM status on EF. CONCLUSIONS T2DM is associated with a mild-to-moderate EF decrements. Such decrements are stronger among those with shorter disease duration.
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154
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Moheet A, Mangia S, Seaquist ER. Impact of diabetes on cognitive function and brain structure. Ann N Y Acad Sci 2015; 1353:60-71. [PMID: 26132277 DOI: 10.1111/nyas.12807] [Citation(s) in RCA: 279] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Both type 1 and type 2 diabetes have been associated with reduced performance on multiple domains of cognitive function and with structural abnormalities in the brain. With an aging population and a growing epidemic of diabetes, central nervous system-related complications of diabetes are expected to rise and could have challenging future public health implications. In this review, we will discuss the brain structural and functional changes that have been associated with type 1 and type 2 diabetes. Diabetes duration and glycemic control may play important roles in the development of cognitive impairment in diabetes, but the exact underlying pathophysiological mechanisms causing these changes in cognition and structure are not well understood. Future research is needed to better understand the natural history and the underlying mechanisms, as well as to identify risk factors that predict who is at greatest risk of developing cognitive impairment. This information will lead to the development of new strategies to minimize the impact of diabetes on cognitive function.
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Affiliation(s)
- Amir Moheet
- Division of Endocrinology and Diabetes, Department of Medicine
| | - Silvia Mangia
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota
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155
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Bednařík P, Moheet A, Deelchand DK, Emir UE, Eberly LE, Bareš M, Seaquist ER, Öz G. Feasibility and reproducibility of neurochemical profile quantification in the human hippocampus at 3 T. NMR IN BIOMEDICINE 2015; 28:685-93. [PMID: 25904240 PMCID: PMC4454404 DOI: 10.1002/nbm.3309] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 03/10/2015] [Accepted: 03/23/2015] [Indexed: 05/21/2023]
Abstract
Hippocampal dysfunction is known to be associated with several neurological and neuropsychiatric disorders such as Alzheimer's disease, epilepsy, schizophrenia and depression; therefore, there has been significant clinical interest in studying hippocampal neurochemistry. However, the hippocampus is a challenging region to study using (1) H MRS, hence the use of MRS for clinical research in this region has been limited. Our goal was therefore to investigate the feasibility of obtaining high-quality hippocampal spectra that allow reliable quantification of a neurochemical profile and to establish inter-session reproducibility of hippocampal MRS, including reproducibility of voxel placement, spectral quality and neurochemical concentrations. Ten healthy volunteers were scanned in two consecutive sessions using a standard clinical 3 T MR scanner. Neurochemical profiles were obtained with a short-echo (T(E) = 28 ms) semi-LASER localization sequence from a relatively small (~4 mL) voxel that covered about 62% of the hippocampal volume as calculated from segmentation of T1 -weighted images. Voxel composition was highly reproducible between sessions, with test-retest coefficients of variation (CVs) of 3.5% and 7.5% for gray and white matter volume fraction, respectively. Excellent signal-to-noise ratio (~54 based on the N-acetylaspartate (NAA) methyl peak in non-apodized spectra) and linewidths (~9 Hz for water) were achieved reproducibly in all subjects. The spectral quality allowed quantification of NAA, total choline, total creatine, myo-inositol and glutamate with high scan-rescan reproducibility (CV ≤ 6%) and quantification precision (Cramér-Rao lower bound, CRLB < 9%). Four other metabolites, including glutathione and glucose, were quantified with scan-rescan CV below 20%. Therefore, the highly optimized, short-echo semi-LASER sequence together with FASTMAP shimming substantially improved the reproducibility and number of quantifiable metabolites relative to prior reports. In addition, the between-session variation in metabolite concentrations, as well as CRLB, was lower than the between-subject variation of the concentrations for most metabolites, indicating that the method has the sensitivity to detect inter-individual differences in the healthy brain.
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Affiliation(s)
- Petr Bednařík
- Center for Magnetic Resonance Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, United States
- Division of Endocrinology and Diabetes, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
- Multimodal and Functional Neuroimaging Research Group, Central European Institute of Technology, CEITEC MU, Brno, Czech Republic
| | - Amir Moheet
- Division of Endocrinology and Diabetes, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Dinesh K. Deelchand
- Center for Magnetic Resonance Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, United States
| | - Uzay E. Emir
- Center for Magnetic Resonance Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, United States
| | - Lynn E. Eberly
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States
| | - Martin Bareš
- Behavioral and Social Neuroscience Research Group, Central European Institute of Technology, CEITEC MU, Brno, Czech Republic
- First Department of Neurology, Masaryk University and St. Anne's Teaching Hospital, Brno, Czech Republic
| | - Elizabeth R. Seaquist
- Division of Endocrinology and Diabetes, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Gülin Öz
- Center for Magnetic Resonance Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, United States
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156
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Kim TE, Lee DH, Kim YJ, Mok JO, Kim CH, Park JH, Lee TK, Yoo K, Jeong Y, Lee Y, Park SA. The relationship between cognitive performance and insulin resistance in non-diabetic patients with mild cognitive impairment. Int J Geriatr Psychiatry 2015; 30:551-7. [PMID: 25060738 DOI: 10.1002/gps.4181] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 07/02/2014] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Insulin resistance (IR) is a distinct and early feature of type 2 diabetes mellitus and metabolic syndrome. IR is thought to play a vital role in cognitive impairment. We conducted this study to understand the early characteristics of cognitive dysfunctions attributable to IR. METHODS This study included 85 consecutive non-diabetic elderly participants with mild cognitive impairment (MCI). IR was estimated with the homeostasis model assessment of insulin resistance (HOMA-IR). Cognitive performances were analyzed as a function of scores on the HOMA-IR. RESULTS The group analysis those with and without IR did not show any differences in the cognitive performance although higher HOMA-IR was closely associated with lower performances in immediate recall on the Seoul Verbal Learning Test (SVLT-I) (r = -0.244, p = 0.026) and Controlled Oral Word Association Test (COWAT) (r = -0.270, p = 0.013). In subgroup analysis by APOE status, SVLT-delayed (p = 0.027) and COWAT (p = 0.016) scores were found to be significantly lower in the IR than the non-IR among those with APOE ε4 allele. In multiple regression analysis, impairment on the COWAT remained significantly correlated with scores on HOMA-IR (β = -0.271, t = -2.340, p = 0.022). However, IR status was identified to interact with APOE ε4 carriership toward poor performances in the COWAT (β = -0.335, t = -2.285, p = 0.026). CONCLUSION This study found a domain-specific impact of HOMA-IR scores on cognitive performances in non-diabetic patients with MCI. This association was profound only in APOE ε4carriers.
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Affiliation(s)
- Tae-Eun Kim
- Department of Neurology, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
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157
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Akintola AA, van den Berg A, van Buchem MA, Jansen SW, Slagboom EP, Westendorp RG, van der Grond J, van Heemst D. Associations between insulin action and integrity of brain microstructure differ with familial longevity and with age. Front Aging Neurosci 2015; 7:92. [PMID: 26074813 PMCID: PMC4446544 DOI: 10.3389/fnagi.2015.00092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 05/03/2015] [Indexed: 11/13/2022] Open
Abstract
Impaired glucose metabolism and type 2 diabetes have been associated with cognitive decline, dementia, and with structural and functional brain features. However, it is unclear whether these associations differ in individuals that differ in familial longevity or age. Here, we investigated the association between parameters of glucose metabolism and microstructural brain integrity in offspring of long-lived families (“offspring”) and controls; and age categories thereof. From the Leiden Longevity Study (LLS), 132 participants underwent an oral glucose tolerance test (OGTT) to assess glycemia [fasted glucose and glucose area-under-the-curve (AUC)], insulin resistance [fasted insulin, AUCinsulin, and homeostatic model assessment of insulin resistance (HOMA-IR)], and pancreatic Beta cell secretory capacity (insulinogenic index). 3 Tesla MRI and Magnetization Transfer (MT) imaging MT-ratio (MTR) peak-height was used to quantify differences in microstructural brain parenchymal tissue homogeneity that remain invisible on conventional MRI. Analyses were performed in offspring and age-matched controls, with and without stratification for age. In the full offspring group only, reduced MTR peak-height in gray and white matter was inversely associated with AUCinsulin, fasted insulin, HOMA-IR and insulinogenic-index (all p < 0.01). When dichotomized for age (≤65 years and >65 years): in younger controls, significantly stronger inverse associations were observed between MTR peak-height and fasted glucose, AUCglucose, fasted insulin, AUCinsulin and HOMA-IR in gray matter; and for AUCglucose, fasted insulin and HOMA-IR in white matter (all P-interaction < 0.05). Although the strength of the associations tended to attenuate with age in the offspring group, the difference between age groups was not statistically significant. Thus, associations between impaired insulin action and reduced microstructural brain parenchymal tissue homogeneity were stronger in offspring compared to controls, and seemed to diminish with age.
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Affiliation(s)
- Abimbola A Akintola
- Department of Gerontology and Geriatrics, Leiden University Medical Centre Leiden, Netherlands
| | | | - Mark A van Buchem
- Department of Radiology, Leiden University Medical Centre Leiden, Netherlands ; Netherlands Consortium for Healthy Ageing Leiden, Netherlands ; Leiden Institute for Brain and Cognition, Leiden University Leiden, Netherlands
| | - Steffy W Jansen
- Department of Gerontology and Geriatrics, Leiden University Medical Centre Leiden, Netherlands
| | - Eline P Slagboom
- Netherlands Consortium for Healthy Ageing Leiden, Netherlands ; Department of Molecular Epidemiology, Leiden University Medical Centre Leiden, Netherlands
| | - Rudi G Westendorp
- Department of Gerontology and Geriatrics, Leiden University Medical Centre Leiden, Netherlands ; Department of Public Health, University of Copenhagen Copenhagen, Denmark
| | - Jeroen van der Grond
- Department of Radiology, Leiden University Medical Centre Leiden, Netherlands ; Netherlands Consortium for Healthy Ageing Leiden, Netherlands
| | - Diana van Heemst
- Department of Gerontology and Geriatrics, Leiden University Medical Centre Leiden, Netherlands ; Netherlands Consortium for Healthy Ageing Leiden, Netherlands
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158
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Diabetes and stem cell function. BIOMED RESEARCH INTERNATIONAL 2015; 2015:592915. [PMID: 26075247 PMCID: PMC4449886 DOI: 10.1155/2015/592915] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 12/01/2014] [Indexed: 12/30/2022]
Abstract
Diabetes mellitus is one of the most common serious metabolic diseases that results in hyperglycemia due to defects of insulin secretion or insulin action or both. The present review focuses on the alterations to the diabetic neuronal tissues and skeletal muscle, including stem cells in both tissues, and the preventive effects of physical activity on diabetes. Diabetes is associated with various nervous disorders, such as cognitive deficits, depression, and Alzheimer's disease, and that may be caused by neural stem cell dysfunction. Additionally, diabetes induces skeletal muscle atrophy, the impairment of energy metabolism, and muscle weakness. Similar to neural stem cells, the proliferation and differentiation are attenuated in skeletal muscle stem cells, termed satellite cells. However, physical activity is very useful for preventing the diabetic alteration to the neuronal tissues and skeletal muscle. Physical activity improves neurogenic capacity of neural stem cells and the proliferative and differentiative abilities of satellite cells. The present review proposes physical activity as a useful measure for the patients in diabetes to improve the physiological functions and to maintain their quality of life. It further discusses the use of stem cell-based approaches in the context of diabetes treatment.
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159
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Hazari MAH, Ram Reddy B, Uzma N, Santhosh Kumar B. Cognitive impairment in type 2 diabetes mellitus. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.ijdm.2011.01.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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160
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Ajilore O, Lamar M, Medina J, Watari K, Elderkin-Thompson V, Kumar A. Disassociation of verbal learning and hippocampal volume in type 2 diabetes and major depression. Int J Geriatr Psychiatry 2015; 30:393-9. [PMID: 24920010 PMCID: PMC4264998 DOI: 10.1002/gps.4149] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 05/08/2014] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The purpose of this study was to examine the relationship between verbal learning and memory performance and hippocampal volume in subjects with co-morbid type 2 diabetes and major depression compared with healthy control subjects and subjects with type 2 diabetes alone. METHODS Twenty four subjects with type 2 diabetes and 20 subjects with type 2 diabetes and major depression were recruited from endocrinology clinics and were compared with 32 healthy control subjects recruited from the community. Subjects were scanned on a 1.5 T GE scanner, and hippocampal volumes were measured using Freesurfer. The California Verbal Learning Test assessed learning and memory. Significant predictors of verbal learning performance (e.g., age, gender, education, blood pressure, stroke risk, hemoglobin A1c, and hippocampal volume) were determined using a stepwise linear regression. RESULTS Subjects with diabetes and depression had significantly worse performance on verbal list learning compared with healthy control subjects. Hippocampal volume was a strong predictor of performance in healthy control subjects, and age and hippocampal volume were strong predictors in subjects with type 2 diabetes alone. Age alone was a significant predictor of verbal learning performance in subjects with diabetes and depression. CONCLUSIONS The relationship between hippocampal volume and performance on the California Verbal Learning Test is decoupled in subjects with type 2 diabetes and major depression and this decoupling may contribute to poor verbal learning and memory performance in this study population.
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Affiliation(s)
- O. Ajilore
- Department of Psychiatry, University of Illinois, Chicago, Chicago, IL, USA,Corresponding author: Olusola Ajilore, 1601 W. Taylor Street, Chicago, Illinois, tel: 312-413-4562, fax: 312-996-7658,
| | - M. Lamar
- Department of Psychiatry, University of Illinois, Chicago, Chicago, IL, USA
| | - J. Medina
- Cognitive Neurology and Alzheimer's Disease Center, Northwestern University, Chicago, IL, USA
| | - K. Watari
- Department of Psychology, University of Southern California, Los Angeles, CA, USA
| | - V. Elderkin-Thompson
- Department of Psychiatry, University of California, Los Angeles, Los Angeles, CA, USA
| | - A. Kumar
- Department of Psychiatry, University of Illinois, Chicago, Chicago, IL, USA
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161
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Taylor SL, Trudeau D, Arnold B, Wang J, Gerrow K, Summerfeldt K, Holmes A, Zamani A, Brocardo PS, Brown CE. VEGF can protect against blood brain barrier dysfunction, dendritic spine loss and spatial memory impairment in an experimental model of diabetes. Neurobiol Dis 2015; 78:1-11. [PMID: 25829228 DOI: 10.1016/j.nbd.2015.03.022] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/23/2015] [Accepted: 03/20/2015] [Indexed: 12/21/2022] Open
Abstract
Clinical and experimental studies have shown a clear link between diabetes, vascular dysfunction and cognitive impairment. However, the molecular underpinnings of this association remain unclear. Since vascular endothelial growth factor (VEGF) signaling is important for maintaining vascular integrity and function, we hypothesized that vascular and cognitive impairment in the diabetic brain could be related to a deficiency in VEGF signaling. Here we show that chronic hyperglycemia (~8weeks) in a mouse model of type 1 diabetes leads to a selective reduction in the expression of VEGF and its cognate receptor (VEGF-R2) in the hippocampus. Correlating with this, diabetic mice showed selective deficits in spatial memory in the Morris water maze, increased vessel area, width and permeability in the dentate gyrus/CA1 region of the hippocampus and reduced spine densities in CA1 neurons. Chronic low dose infusion of VEGF in diabetic mice was sufficient to restore VEGF signaling, protect them from memory deficits, as well as vascular and synaptic abnormalities in the hippocampus. These findings suggest that a hippocampal specific reduction in VEGF signaling and resultant vascular/neuronal defects may underlie early manifestations of cognitive impairment commonly associated with diabetes. Furthermore, restoring VEGF signaling may be a useful strategy for preserving hippocampal-related brain circuitry in degenerative vascular diseases.
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Affiliation(s)
- Stephanie L Taylor
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Dustin Trudeau
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Brendan Arnold
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Joshua Wang
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Kim Gerrow
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Kieran Summerfeldt
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Andrew Holmes
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Akram Zamani
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Patricia S Brocardo
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Craig E Brown
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada; Department of Biology, University of Victoria, Victoria, BC V8P 5C2, Canada; Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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162
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Insulin resistance in brain alters dopamine turnover and causes behavioral disorders. Proc Natl Acad Sci U S A 2015; 112:3463-8. [PMID: 25733901 DOI: 10.1073/pnas.1500877112] [Citation(s) in RCA: 291] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Diabetes and insulin resistance are associated with altered brain imaging, depression, and increased rates of age-related cognitive impairment. Here we demonstrate that mice with a brain-specific knockout of the insulin receptor (NIRKO mice) exhibit brain mitochondrial dysfunction with reduced mitochondrial oxidative activity, increased levels of reactive oxygen species, and increased levels of lipid and protein oxidation in the striatum and nucleus accumbens. NIRKO mice also exhibit increased levels of monoamine oxidase A and B (MAO A and B) leading to increased dopamine turnover in these areas. Studies in cultured neurons and glia cells indicate that these changes in MAO A and B are a direct consequence of loss of insulin signaling. As a result, NIRKO mice develop age-related anxiety and depressive-like behaviors that can be reversed by treatment with MAO inhibitors, as well as the tricyclic antidepressant imipramine, which inhibits MAO activity and reduces oxidative stress. Thus, insulin resistance in brain induces mitochondrial and dopaminergic dysfunction leading to anxiety and depressive-like behaviors, demonstrating a potential molecular link between central insulin resistance and behavioral disorders.
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163
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Hajek T, Calkin C, Blagdon R, Slaney C, Alda M. Type 2 diabetes mellitus: a potentially modifiable risk factor for neurochemical brain changes in bipolar disorders. Biol Psychiatry 2015; 77:295-303. [PMID: 24331546 DOI: 10.1016/j.biopsych.2013.11.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Revised: 11/08/2013] [Accepted: 11/08/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND Neuroimaging changes in bipolar disorder (BD) may be secondary to the presence of certain clinical factors. Type 2 diabetes mellitus (T2DM) damages the brain and frequently co-occurs with BD. Studying patients with both T2DM and BD could help identify preventable risk factors for neuroimaging changes in BD. METHODS We used 1.5T magnetic resonance spectroscopy to measure prefrontal N-acetylaspartate (NAA), which is mainly localized in neurons, and total creatine (tCr), an energy metabolite, in 19 BD patients with insulin resistance/glucose intolerance (BD + IR/GI), 14 BD subjects with T2DM (BD + T2DM), 15 euglycemic BD participants, and 11 euglycemic, nonpsychiatric control. RESULTS The levels of NAA and tCr were lowest among BD + T2DM, intermediate in the BD + IR/GI, and highest among the euglycemic BD and control subjects (F₃,₅₅ = 4.57, p = .006; F₃,₅₅ = 2.92, p = .04, respectively). Even the BD + IR/GI subjects had lower NAA than the euglycemic participants (t₄₃ = 2.13, p = .04). Total Cr was associated with NAA (β = .52, t₅₆ = 5.57, p = .000001). Both NAA and tCr correlated with Global Assessment of Functioning scores (r₄₆ = .28, p = .05; r₄₆ = .48, p = .0004, respectively). CONCLUSIONS T2DM, but also prediabetes, may be risk factors for prefrontal neurochemical alterations in BD. These changes were associated with poor psychosocial functioning and could indicate impaired energy metabolism. The findings emphasize the importance of improving diabetes care in BD and suggest potential options for treatment of neuroimaging alterations.
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Affiliation(s)
- Tomas Hajek
- Department of Psychiatry (TH, CC, RB, CS, MA), Dalhousie University, Halifax, Nova Scotia, Canada; Prague Psychiatric Center (TH, MA), Department of Psychiatry and Medical Psychology, 3rd School of Medicine, Charles University, Prague, Czech Republic.
| | - Cynthia Calkin
- Department of Psychiatry (TH, CC, RB, CS, MA), Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ryan Blagdon
- Department of Psychiatry (TH, CC, RB, CS, MA), Dalhousie University, Halifax, Nova Scotia, Canada
| | - Claire Slaney
- Department of Psychiatry (TH, CC, RB, CS, MA), Dalhousie University, Halifax, Nova Scotia, Canada
| | - Martin Alda
- Department of Psychiatry (TH, CC, RB, CS, MA), Dalhousie University, Halifax, Nova Scotia, Canada; Prague Psychiatric Center (TH, MA), Department of Psychiatry and Medical Psychology, 3rd School of Medicine, Charles University, Prague, Czech Republic
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164
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Sink KM, Divers J, Whitlow CT, Palmer ND, Smith SC, Xu J, Hugenschmidt CE, Wagner BC, Williamson JD, Bowden DW, Maldjian JA, Freedman BI. Cerebral structural changes in diabetic kidney disease: African American-Diabetes Heart Study MIND. Diabetes Care 2015; 38:206-12. [PMID: 25205141 PMCID: PMC4302263 DOI: 10.2337/dc14-1231] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Albuminuria and reduced kidney function are associated with cognitive impairment. Relationships between nephropathy and cerebral structural changes remain poorly defined, particularly in African Americans (AAs), a population at higher risk for both cognitive impairment and diabetes than European Americans. We examined the relationship between urine albumin:creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), and cerebral MRI volumes in 263 AAs with type 2 diabetes. RESEARCH DESIGN AND METHODS Cross-sectional associations between renal parameters and white matter (WM), gray matter (GM), hippocampal, and WM lesion (WML) volumes were assessed using generalized linear models adjusted for age, education, sex, BMI, hemoglobin A1c (HbA1c) level, and hypertension. RESULTS Participants had a mean (SD) age of 60.2 years (9.7 years), and 62.7% were female. Mean diabetes duration was 14.3 years (8.9 years), HbA1c level was 8.2% (2.2%; 66 mmol/mol), eGFR was 86.0 mL/min/1.73 m(2) (23.2 mL/min/1.73 m(2)), and UACR was 155.8 mg/g (542.1 mg/g; median 8.1 mg/g). Those with chronic kidney disease (CKD) (eGFR <60 mL/min/1.73 m(2) or UACR >30 mg/g) had smaller GM and higher WML volumes. Higher UACR was significantly associated with higher WML volume and greater atrophy (larger cerebrospinal fluid volumes), and smaller GM and hippocampal WM volumes. A higher eGFR was associated with larger hippocampal WM volumes. Consistent with higher WML volumes, participants with CKD had significantly poorer processing speed and working memory. These findings were independent of glycemic control. CONCLUSIONS We found albuminuria to be a better marker of cerebral structural changes than eGFR in AAs with type 2 diabetes. Relationships between albuminuria and brain pathology may contribute to poorer cognitive performance in patients with mild CKD.
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Affiliation(s)
- Kaycee M Sink
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC
| | - Jasmin Divers
- Division of Public Health Sciences, Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC
| | - Christopher T Whitlow
- Department of Radiologic Sciences, Advanced Neuroscience Imaging Research Laboratory, Wake Forest School of Medicine, Winston-Salem, NC
| | - Nicholette D Palmer
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC Center for Diabetes Research, Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC
| | - S Carrie Smith
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC
| | - Jianzhao Xu
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC
| | - Christina E Hugenschmidt
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC
| | - Benjamin C Wagner
- Department of Radiologic Sciences, Advanced Neuroscience Imaging Research Laboratory, Wake Forest School of Medicine, Winston-Salem, NC
| | - Jeff D Williamson
- Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC
| | - Donald W Bowden
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC Center for Diabetes Research, Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC
| | - Joseph A Maldjian
- Department of Radiologic Sciences, Advanced Neuroscience Imaging Research Laboratory, Wake Forest School of Medicine, Winston-Salem, NC
| | - Barry I Freedman
- Center for Diabetes Research, Center for Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, NC Department of Internal Medicine, Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, NC
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The neuroprotective role of metformin in advanced glycation end product treated human neural stem cells is AMPK-dependent. Biochim Biophys Acta Mol Basis Dis 2015; 1852:720-31. [PMID: 25595658 DOI: 10.1016/j.bbadis.2015.01.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 01/05/2015] [Accepted: 01/08/2015] [Indexed: 12/17/2022]
Abstract
Diabetic neuronal damage results from hyperglycemia followed by increased formation of advanced glycosylation end products (AGEs), which leads to neurodegeneration, although the molecular mechanisms are still not well understood. Metformin, one of the most widely used anti-diabetic drugs, exerts its effects in part by activation of AMP-activated protein kinase (AMPK). AMPK is a critical evolutionarily conserved enzyme expressed in the liver, skeletal muscle and brain, and promotes cellular energy homeostasis and biogenesis by regulating several metabolic processes. While the mechanisms of AMPK as a metabolic regulator are well established, the neuronal role for AMPK is still unknown. In the present study, human neural stem cells (hNSCs) exposed to AGEs had significantly reduced cell viability, which correlated with decreased AMPK and mitochondria associated gene/protein (PGC1α, NRF-1 and Tfam) expressions, as well as increased activation of caspase 3 and 9 activities. Metformin prevented AGEs induced cytochrome c release from mitochondria into cytosol in the hNSCs. Co-treatment with metformin significantly abrogated the AGE-mediated effects in hNSCs. Metformin also significantly rescued hNSCs from AGE-mediated mitochondrial deficiency (lower ATP, D-loop level, mitochondrial mass, maximal respiratory function, COX activity, and mitochondrial membrane potential). Furthermore, co-treatment of hNSCs with metformin significantly blocked AGE-mediated reductions in the expression levels of several neuroprotective genes (PPARγ, Bcl-2 and CREB). These findings extend our understanding of the molecular mechanisms of both AGE-induced neuronal toxicity, and AMPK-dependent neuroprotection by metformin. This study further suggests that AMPK may be a potential therapeutic target for treating diabetic neurodegeneration.
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166
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Ma L, Feng M, Qian Y, Yang W, Liu J, Han R, Zhu H, Li Y. Insulin resistance is an important risk factor for cognitive impairment in elderly patients with primary hypertension. Yonsei Med J 2015; 56:89-94. [PMID: 25510751 PMCID: PMC4276782 DOI: 10.3349/ymj.2015.56.1.89] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
PURPOSE Insulin resistance plays a role in the development of dementia and hypertension. We investigated a possible relationship between cognitive impairment and insulin resistance in elderly Chinese patients with primary hypertension. MATERIALS AND METHODS One hundred and thirty-two hypertensive elderly patients (>60 years) were enrolled in this study, and assigned into either the cognitive impairment group (n=61) or the normal cognitive group (n=71). Gender, age, education, body mass index (BMI), waist hip ratio (WHR), total cholesterol (TC), triglyceride (TG), C-reactive protein (CRP), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), creatinine (Cr), fasting plasma glucose (FPG), fasting insulin (FINS), homeostasis model of assessment for insulin resistance index (HOMA-IR), systolic blood pressure, diastolic blood pressure, smoking history, atherosclerosis and the proportion of uncontrolled hypertension were compared between the two groups. Multi-factorial logistic regression analysis was performed. RESULTS No significant differences were found in gender, age, TC, CRP, HDL-C, LDL-C, Cr, BP, smoking history, atherosclerosis and the proportion of uncontrolled hypertension between the two groups. The cognitive impairment group had lower education levels, and higher BMI, WHR, TG, FPG, FINS, and HOMA-IR levels than the control group. Logistic regression analysis revealed the levels of education, BMI, WHR, and HOMA-IR as independent factors that predict cognitive impairment in patients. CONCLUSION Our study demonstrates that poor education and increased BMI, WHR, and HOMA-IR are independent risk factors for cognitive impairment in elderly patients with hypertension. Insulin resistance plays an important role in the development of cognitive impairment in primary elderly hypertensive patients.
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Affiliation(s)
- Lina Ma
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Ming Feng
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Yuying Qian
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Wei Yang
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Jia Liu
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Rui Han
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Hong Zhu
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Yun Li
- Department of Geriatrics, Xuan Wu Hospital, Capital Medical University, Beijing, China.
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167
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Ward AM, Mormino EC, Huijbers W, Schultz AP, Hedden T, Sperling RA. Relationships between default-mode network connectivity, medial temporal lobe structure, and age-related memory deficits. Neurobiol Aging 2015; 36:265-72. [PMID: 25113793 PMCID: PMC4268379 DOI: 10.1016/j.neurobiolaging.2014.06.028] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 06/17/2014] [Accepted: 06/28/2014] [Indexed: 10/25/2022]
Abstract
Advanced aging negatively impacts memory performance. Brain aging has been associated with shrinkage in medial temporal lobe structures essential for memory--including hippocampus and entorhinal cortex--and with deficits in default-mode network connectivity. Yet, whether and how these imaging markers are relevant to age-related memory deficits remains a topic of debate. Using a sample of 182 older (age 74.6 ± 6.2 years) and 66 young (age 22.2 ± 3.6 years) participants, this study examined relationships among memory performance, hippocampus volume, entorhinal cortex thickness, and default-mode network connectivity across aging. All imaging markers and memory were significantly different between young and older groups. Each imaging marker significantly mediated the relationship between age and memory performance and collectively accounted for most of the variance in age-related memory performance. Within older participants, default-mode connectivity and hippocampus volume were independently associated with memory. Structural equation modeling of cross-sectional data within older participants suggest that entorhinal thinning may occur before reduced default-mode connectivity and hippocampal volume loss, which in turn lead to deficits in memory performance.
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Affiliation(s)
- Andrew M Ward
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Elizabeth C Mormino
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Willem Huijbers
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Aaron P Schultz
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
| | - Trey Hedden
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA; Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Reisa A Sperling
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA; Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Boston, MA, USA.
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168
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Salak Djokić B, Spitznagel MB, Pavlović D, Janković N, Parojčić A, Ilić V, Nikolić Djurović M. Diabetes mellitus and cognitive functioning in a Serbian sample. J Clin Exp Neuropsychol 2014; 37:37-48. [DOI: 10.1080/13803395.2014.985190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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169
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Barbagallo M, Dominguez LJ. Type 2 diabetes mellitus and Alzheimer’s disease. World J Diabetes 2014; 5:889-893. [PMID: 25512792 PMCID: PMC4265876 DOI: 10.4239/wjd.v5.i6.889] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/17/2014] [Accepted: 11/03/2014] [Indexed: 02/05/2023] Open
Abstract
Epidemiological and biological evidences support a link between type 2 diabetes mellitus (DM2) and Alzheimer’s disease (AD). Persons with diabetes have a higher incidence of cognitive decline and an increased risk of developing all types of dementia. Cognitive deficits in persons with diabetes mainly affect the areas of psychomotor efficiency, attention, learning and memory, mental flexibility and speed, and executive function. The strong epidemiological association has suggested the existence of a physiopathological link. The determinants of the accelerated cognitive decline in DM2, however, are less clear. Increased cortical and subcortical atrophy have been evidenced after controlling for diabetic vascular disease and inadequate cerebral circulation. Most recent studies have focused on the role of insulin and insulin resistance as possible links between diabetes and AD. Disturbances in brain insulin signaling mechanisms may contribute to the molecular, biochemical, and histopathological lesions in AD. Hyperglycemia itself is a risk factor for cognitive dysfunction and dementia. Hypoglycemia may also have deleterious effects on cognitive function. Recurrent symptomatic and asymptomatic hypoglycemic episodes have been suggested to cause sub-clinical brain damage, and permanent cognitive impairment. Future trials are required to clarify the mechanistic link, to address the question whether cognitive decline may be prevented by an adequate metabolic control, and to elucidate the role of drugs that may cause hypoglycemic episodes.
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170
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Brundel M, Kappelle LJ, Biessels GJ. Brain imaging in type 2 diabetes. Eur Neuropsychopharmacol 2014; 24:1967-81. [PMID: 24726582 DOI: 10.1016/j.euroneuro.2014.01.023] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 01/23/2014] [Indexed: 02/08/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is associated with cognitive dysfunction and dementia. Brain imaging may provide important clues about underlying processes. This review focuses on the relationship between T2DM and brain abnormalities assessed with different imaging techniques: both structural and functional magnetic resonance imaging (MRI), including diffusion tensor imaging and magnetic resonance spectroscopy, as well as positron emission tomography and single-photon emission computed tomography. Compared to people without diabetes, people with T2DM show slightly more global brain atrophy, which increases gradually over time compared with normal aging. Moreover, vascular lesions are seen more often, particularly lacunar infarcts. The association between T2DM and white matter hyperintensities and microbleeds is less clear. T2DM has been related to diminished cerebral blood flow and cerebrovascular reactivity, particularly in more advanced disease. Diffusion tensor imaging is a promising technique with respect to subtle white matter involvement. Thus, brain imaging studies show that T2DM is associated with both degenerative and vascular brain damage, which develops slowly over the course of many years. The challenge for future studies will be to further unravel the etiology of brain damage in T2DM, and to identify subgroups of patients that will develop distinct progressive brain damage and cognitive decline.
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Affiliation(s)
- Manon Brundel
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands.
| | - L Jaap Kappelle
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
| | - Geert Jan Biessels
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
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171
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Chen Y, Liu Z, Zhang J, Xu K, Zhang S, Wei D, Zhang Z. Altered brain activation patterns under different working memory loads in patients with type 2 diabetes. Diabetes Care 2014; 37:3157-63. [PMID: 25404661 DOI: 10.2337/dc14-1683] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Type 2 diabetes mellitus (T2DM) has important effects on cognition and the risk for Alzheimer disease (AD). Working memory (WM) is a susceptible cognitive domain of mild cognitive impairment and AD. Thus, the identification of brain activation patterns under different WM loads can potentially enhance our understanding of the mechanisms underlying cognitive dysfunction in T2DM. RESEARCH DESIGN AND METHODS The current study assessed the effects of T2DM on cognitive performance and explored the related neuronal damage through a visual n-back task and functional magnetic resonance imaging. RESULTS We found that patients with T2DM exhibited worse executive and memory abilities than control subjects. Furthermore, the patterns of brain activation changed under different WM loads in the T2DM patients, who exhibited reduced activation in the left inferior frontal gyrus under low loads and reduced activation in the left middle frontal gyrus and superior frontal gyrus (SFG) under high loads. Thus, more regions of diminished activation were seen in the frontal cortex with increasing task difficulty. Furthermore, we found that lower SFG activation was associated with worse cognitive function. CONCLUSIONS The findings demonstrate deficient WM in patients with T2DM and the relation between cognitive function and degree of neuronal activity and their relevance to AD risk. Further longitudinal studies are needed to replicate these results and to evaluate the clinical value of brain imaging methods in the prediction of disease progress in these patients.
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Affiliation(s)
- Yaojing Chen
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Zhen Liu
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Junying Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Kai Xu
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Sisi Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Dongfeng Wei
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| | - Zhanjun Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China BABRI Centre, Beijing Normal University, Beijing, China Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China Institute of Basic Research in Clinical Medicine, China Academy of Traditional Chinese Medicine, Beijing, China
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Mehta D, Pimentel DA, Núñez MZ, Abduljalil A, Novak V. Subclinical albuminuria is linked to gray matter atrophy in type 2 diabetes mellitus. Metabolism 2014; 63:1390-7. [PMID: 25216926 PMCID: PMC4198475 DOI: 10.1016/j.metabol.2014.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/15/2014] [Accepted: 07/22/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Microalbuminuria (MA), a marker of renal microvascular disease, is associated with brain atrophy and neurovascular changes in older adults with type 2 diabetes mellitus (DM). We evaluated the relationship between urine albumin-to-creatinine ratio (UACR) and regional brain volumes to determine whether subclinical albuminuria may indicate early structural brain changes in type 2 DM. MATERIALS/METHODS We studied UACR and brain volumes in 85 type 2 DM patients (64.8±8.3years) and 40 age-matched controls using 3D magnetization prepared rapid acquisition with gradient echo (MP-RAGE) MRI (magnetic resonance imaging) at 3 Tesla. The relationship between UACR and brain volumes was analyzed using the least square models. RESULTS In DM patients, UACR ≥5mg/g, UACR ≥10mg/g and clinically significant MA (UACR ≥17mg/g [males] and 25mg/g [females]) were associated with lower gray matter (GM) volume in the frontal lobe (r(2)adj=0.2-0.4, P=0.01-0.05) and UACR ≥5mg/g was also related to global GM atrophy (r(2)adj=0.1, P=0.04), independent of DM duration, glucose levels, HbA1c and hypertension. For UACR ≥5mg/g, a lower global GM volume was related to worse executive function (P=0.04) in the DM group. No associations were found for UACR (<5mg/g) and controls. CONCLUSIONS Subclinical albuminuria (UACR ≥5mg/g) is associated with lower GM volume that has clinical impact on cognitive function in older diabetic patients, and these relationships are independent of DM control and hypertension. Therefore, UACR levels may serve as an additional marker of DM-related brain structural changes.
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Affiliation(s)
- Disha Mehta
- Division of Gerontology, Beth Israel Deaconess Medical Center, Harvard Medical School, 185 Pilgrim Road, Palmer 117, Boston, MA 02215, USA
| | - Daniela A. Pimentel
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 185 Pilgrim Road, Palmer 127, Boston, MA 02215, USA
| | - Maria-Zunilda Núñez
- Centro de Investigaciones Biomédicas y Clínicas (CINBIOCLI), Hospital José María Cabral y Báez, Av. 27 de Febrero, Santiago, Dominican Republic
| | - Amir Abduljalil
- Department of Radiology, Ohio State University, 395 W. 12th Avenue, Columbus, OH, USA
| | - Vera Novak
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 185 Pilgrim Road, Palmer 127, Boston, MA 02215, USA
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173
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Hajek T, Calkin C, Blagdon R, Slaney C, Uher R, Alda M. Insulin resistance, diabetes mellitus, and brain structure in bipolar disorders. Neuropsychopharmacology 2014; 39:2910-8. [PMID: 25074491 PMCID: PMC4200504 DOI: 10.1038/npp.2014.148] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 05/27/2014] [Accepted: 06/05/2014] [Indexed: 12/21/2022]
Abstract
Type 2 diabetes mellitus (T2DM) damages the brain, especially the hippocampus, and frequently co-occurs with bipolar disorders (BD). Reduced hippocampal volumes are found only in some studies of BD subjects and may thus be secondary to the presence of certain clinical variables. Studying BD patients with abnormal glucose metabolism could help identify preventable risk factors for hippocampal atrophy in BD. We compared brain structure using optimized voxel-based morphometry of 1.5T MRI scans in 33 BD subjects with impaired glucose metabolism (19 with insulin resistance/glucose intolerance (IR/GI), 14 with T2DM), 15 euglycemic BD participants and 11 euglycemic, nonpsychiatric controls. The group of BD patients with IR, GI or T2DM had significantly smaller hippocampal volumes than the euglycemic BD participants (corrected p=0.02) or euglycemic, nonpsychiatric controls (corrected p=0.004). Already the BD subjects with IR/GI had smaller hippocampal volumes than euglycemic BD participants (t(32)=-3.15, p=0.004). Age was significantly more negatively associated with hippocampal volumes in BD subjects with IR/GI/T2DM than in the euglycemic BD participants (F(2, 44)=9.96, p=0.0003). The gray matter reductions in dysglycemic subjects extended to the cerebral cortex, including the insula. In conclusion, this is the first study demonstrating that T2DM or even prediabetes may be risk factors for smaller hippocampal and cortical volumes in BD. Abnormal glucose metabolism may accelerate the age-related decline in hippocampal volumes in BD. These findings raise the possibility that improving diabetes care among BD subjects and intervening already at the level of prediabetes could slow brain aging in BD.
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Affiliation(s)
- Tomas Hajek
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada,Prague Psychiatric Center, Department of Psychiatry and Medical Psychology, 3rd School of Medicine, Charles University, Prague, Czech Republic,Department of Psychiatry, Dalhousie University, QEII HSC, A.J.Lane Bldg., Room 3093, 5909 Veteran's Memorial Lane, Halifax, NS B3H 2E2, Canada, Tel: +1 902 473 8299, Fax: +1 902 473 1583, E-mail:
| | - Cynthia Calkin
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Ryan Blagdon
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Claire Slaney
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Rudolf Uher
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada,Prague Psychiatric Center, Department of Psychiatry and Medical Psychology, 3rd School of Medicine, Charles University, Prague, Czech Republic
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Climie RED, Srikanth V, Beare R, Keith LJ, Fell J, Davies JE, Sharman JE. Aortic reservoir characteristics and brain structure in people with type 2 diabetes mellitus; a cross sectional study. Cardiovasc Diabetol 2014; 13:143. [PMID: 25338824 PMCID: PMC4221700 DOI: 10.1186/s12933-014-0143-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 10/06/2014] [Indexed: 01/09/2023] Open
Abstract
Background Central hemodynamics help to maintain appropriate cerebral and other end-organ perfusion, and may be altered with ageing and type 2 diabetes mellitus (T2DM). We aimed to determine the associations between central hemodynamics and brain structure at rest and during exercise in people with and without T2DM. Methods In a sample of people with T2DM and healthy controls, resting and exercise measures of aortic reservoir characteristics (including excess pressure integral [Pexcess]) and other central hemodynamics (including augmentation index [AIx] and aortic pulse wave velocity [aPWV]) were recorded. Brain volumes (including gray matter volume [GMV] and white matter lesions [WML]) were derived from magnetic resonance imaging (MRI) scans. Multivariable linear regression was used to study the associations of hemodynamic variables with brain structure in the two groups adjusting for age, sex, daytime systolic BP (SBP) and heart rate. Results There were 37 T2DM (63 ± 9 years; 47% male) and 37 healthy individuals (52 ± 8 years; 51% male). In T2DM, resting aPWV was inversely associated with GMV (standardized β = −0.47, p = 0.036). In healthy participants, resting Pexcess was inversely associated with GMV (β = −0.23, p = 0.043) and AIx was associated with WML volume (β = 0.52, p = 0.021). There were no associations between exercise hemodynamics and brain volumes in either group. Conclusions Brain atrophy is associated with resting aortic stiffness in T2DM, and resting Pexcess in healthy individuals. Central vascular mechanisms underlying structural brain changes may differ between healthy individuals and T2DM.
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175
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Ng A, Jion YI, Zainal NH, Kandiah N. Renal Dysfunction Contributes to Episodic Memory Deficits and Medial Temporal Atrophy in Alzheimer's Disease: A Pilot Study. J Am Geriatr Soc 2014; 62:1981-2. [DOI: 10.1111/jgs.13034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aloysius Ng
- Department of Neurology; National Neuroscience Institute; Singapore City Singapore
| | - Yasmin Idu Jion
- Department of Neurology; National Neuroscience Institute; Singapore City Singapore
| | - Nur Hani Zainal
- Department of Neurology; National Neuroscience Institute; Singapore City Singapore
| | - Nagaendran Kandiah
- Department of Neurology; National Neuroscience Institute; Singapore City Singapore
- Duke-National University of Singapore; Singapore City Singapore
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176
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Genetic, psychosocial and clinical factors associated with hippocampal volume in the general population. Transl Psychiatry 2014; 4:e465. [PMID: 25313508 PMCID: PMC4350511 DOI: 10.1038/tp.2014.102] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 08/13/2014] [Indexed: 01/14/2023] Open
Abstract
The hippocampus--crucial for memory formation, recall and mood regulation--is involved in the pathophysiology of dementia and depressive disorders. Recent genome-wide association studies (GWAS) have identified five genetic loci associated with hippocampal volume (HV). Previous studies have described psychosocial and clinical factors (for example, smoking, type 2 diabetes and hypertension) to have an impact on HV. However, the interplay between genetic, psychosocial and clinical factors on the HV remains unclear. Still, it is likely that genetic variants and clinical or psychosocial factors jointly act in modifying HV; it might be possible they even interact. Knowledge of these factors might help to quantify ones individual risk of or rather resilience against HV loss. We investigated subjects (N=2463; 55.7% women; mean age 53 years) from the Study of Health in Pomerania (SHIP-2; SHIP-TREND-0) who underwent whole-body magnetic resonance imaging (MRI) and genotyping. HVs were estimated with FreeSurfer. For optimal nonlinear model fitting, we used regression analyses with restricted cubic splines. Genetic variants and associated psychosocial or clinical factors were jointly assessed for potential two-way interactions. We observed associations between HV and gender (P<0.0001), age (P<0.0001), body height (P<0.0001), education (P=0.0053), smoking (P=0.0058), diastolic blood pressure (P=0.0211), rs7294919 (P=0.0065), rs17178006 (P=0.0002), rs6581612 (P=0.0036), rs6741949 (P=0.0112) and rs7852872 (P=0.0451). In addition, we found three significant interactions: between rs7294919 and smoking (P=0.0473), rs7294919 and diastolic blood pressure (P=0.0447) and between rs7852872 and rs6581612 (P=0.0114). We suggest that these factors might have a role in the individual susceptibility to hippocampus-associated disorders.
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177
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Hishikawa N, Yamashita T, Deguchi K, Wada J, Shikata K, Makino H, Abe K. Cognitive and affective functions in diabetic patients associated with diabetes-related factors, white matter abnormality and aging. Eur J Neurol 2014; 22:313-21. [DOI: 10.1111/ene.12568] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 08/01/2014] [Indexed: 01/21/2023]
Affiliation(s)
- N. Hishikawa
- Department of Neurology; Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - T. Yamashita
- Department of Neurology; Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - K. Deguchi
- Department of Neurology; Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - J. Wada
- Department of Medicine and Clinical Science; Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - K. Shikata
- Department of Medicine and Clinical Science; Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - H. Makino
- Department of Medicine and Clinical Science; Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
| | - K. Abe
- Department of Neurology; Graduate School of Medicine; Dentistry and Pharmaceutical Sciences; Okayama University; Okayama Japan
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178
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Cui D, Liu J, Bian Z, Li Q, Wang L, Li X. Cortical source multivariate EEG synchronization analysis on amnestic mild cognitive impairment in type 2 diabetes. ScientificWorldJournal 2014; 2014:523216. [PMID: 25254248 PMCID: PMC4164801 DOI: 10.1155/2014/523216] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/14/2014] [Indexed: 02/06/2023] Open
Abstract
Is synchronization altered in amnestic mild cognitive impairment (aMCI) and normal cognitive functions subjects in type 2 diabetes mellitus (T2DM)? Resting eye-closed EEG data were recorded in 8 aMCI subjects and 11 age-matched controls in T2DM. Three multivariate synchronization algorithms (S-estimator (S), synchronization index (SI), and global synchronization index (GSI)) were used to measure the synchronization in five ROIs of sLORETA sources for seven bands. Results showed that aMCI group had lower synchronization values than control groups in parietal delta and beta2 bands, temporal delta and beta2 bands, and occipital theta and beta2 bands significantly. Temporal (r = 0.629; P = 0.004) and occipital (r = 0.648; P = 0.003) theta S values were significantly positive correlated with Boston Name Testing. In sum, each of methods reflected that the cortical source synchronization was significantly different between aMCI and control group, and these difference correlated with cognitive functions.
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Affiliation(s)
- Dong Cui
- School of Information Science and Engineering, Yanshan University, Qinhuangdao 066004, China
| | - Jing Liu
- School of Information Science and Engineering, Yanshan University, Qinhuangdao 066004, China
| | - Zhijie Bian
- School of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China
| | - Qiuli Li
- Department of Neurology, General Hospital of Second Artillery Corps of PLA, Beijing 100875, China
| | - Lei Wang
- Department of Neurology, General Hospital of Second Artillery Corps of PLA, Beijing 100875, China
| | - Xiaoli Li
- School of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing 100875, China
- National Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
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179
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Seetharaman S, Andel R, McEvoy C, Dahl Aslan AK, Finkel D, Pedersen NL. Blood glucose, diet-based glycemic load and cognitive aging among dementia-free older adults. J Gerontol A Biol Sci Med Sci 2014; 70:471-9. [PMID: 25149688 DOI: 10.1093/gerona/glu135] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Although evidence indicates that Type II Diabetes is related to abnormal brain aging, the influence of elevated blood glucose on long-term cognitive change is unclear. In addition, the relationship between diet-based glycemic load and cognitive aging has not been extensively studied. The focus of this study was to investigate the influence of diet-based glycemic load and blood glucose on cognitive aging in older adults followed for up to 16 years. METHODS Eight-hundred and thirty-eight cognitively healthy adults aged ≥50 years (M = 63.1, SD = 8.3) from the Swedish Adoption/Twin Study of Aging were studied. Mixed effects growth models were utilized to assess overall performance and change in general cognitive functioning, perceptual speed, memory, verbal ability, and spatial ability as a function of baseline blood glucose and diet-based glycemic load. RESULTS High blood glucose was related to poorer overall performance on perceptual speed as well as greater rates of decline in general cognitive ability, perceptual speed, verbal ability, and spatial ability. Diet-based glycemic load was related to poorer overall performance in perceptual speed and spatial ability. CONCLUSION Diet-based glycemic load and, in particular, elevated blood glucose appear important for cognitive performance/cognitive aging. Blood glucose control (perhaps through low glycemic load diets) may be an important target in the detection and prevention of age-related cognitive decline.
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Affiliation(s)
- Shyam Seetharaman
- Department of Psychology. St. Petersburg College. St. Petersburg, Florida..
| | - Ross Andel
- School of Aging Studies. University of South Florida. Tampa, International Clinical Research Center, Brno, Czech Republic
| | - Cathy McEvoy
- School of Aging Studies. University of South Florida. Tampa
| | - Anna K Dahl Aslan
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden School of Health Sciences. Jönköping University, Jönköping, Sweden
| | - Deborah Finkel
- Department of Psychology. Indiana University Southeast, New Albany, Indiana
| | - Nancy L Pedersen
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden Department of Psychology. University of Southern California. Los Angeles, California
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180
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Abstract
Insulin receptors, as well as IGF-1 receptors and their postreceptor signaling partners, are distributed throughout the brain. Insulin acts on these receptors to modulate peripheral metabolism, including regulation of appetite, reproductive function, body temperature, white fat mass, hepatic glucose output, and response to hypoglycemia. Insulin signaling also modulates neurotransmitter channel activity, brain cholesterol synthesis, and mitochondrial function. Disruption of insulin action in the brain leads to impairment of neuronal function and synaptogenesis. In addition, insulin signaling modulates phosphorylation of tau protein, an early component in the development of Alzheimer disease. Thus, alterations in insulin action in the brain can contribute to metabolic syndrome, and the development of mood disorders and neurodegenerative diseases.
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Affiliation(s)
- André Kleinridders
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA
| | - Heather A Ferris
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA
| | - Weikang Cai
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA
| | - C Ronald Kahn
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, MA
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181
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Abstract
Type 2 diabetes mellitus (T2DM) is a risk factor for cognitive dysfunction and dementia in the elderly. T2DM has been thought to be associated with vascular diseases, eventually leading to vascular dementia, but recent studies have established that T2DM is also associated with Alzheimer's disease (AD). With the increase in the number of elderly individuals with T2DM, the number of diabetic patients with cognitive dysfunction has been increasing. T2DM may accelerate AD-associated pathologies through insulin resistance. Vascular pathologies may also be associated with cognitive dysfunction and dementia in T2DM subjects. Several other mechanisms also seem to be involved in T2DM-related cognitive dysfunction. More investigations to clarify the association of T2DM with cognitive impairment are warranted. These investigations may help to increase our understanding of AD and open a new door to the development of therapeutics. Recent pharmaceutical advancement in T2DM treatment has resulted in the availability of a wide range of antidiabetics. Some evidence has suggested that antidiabetic therapies help to prevent cognitive dysfunction. At present, however, the optimal level of blood glucose control and the best combination of medications to achieve it in terms of cognitive preservation have not been established. More investigation is warranted. Cognitive dysfunction is an emerging new complication of T2DM that requires further study.
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Affiliation(s)
- Hiroyuki Umegaki
- Department of Community Healthcare and Geriatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
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182
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Smith MA, Else JE, Paul L, Foster JK, Walker M, Wesnes KA, Riby LM. Functional Living in Older Adults With Type 2 Diabetes: Executive Functioning, Dual Task Performance, and the Impact on Postural Stability and Motor Control. J Aging Health 2014; 26:841-859. [PMID: 24898849 DOI: 10.1177/0898264314534896] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Older adults with type 2 diabetes mellitus (DM2) experience accelerated age-related decline in some domains of cognition. The present study sought to investigate executive functioning and dual tasking capacities in this group. METHOD Older adults with DM2 and age-matched controls completed self-report measures assessing everyday activities, a comprehensive cognitive battery and more specific tasks assessing executive functioning, dual tasking, postural stability, and motor control. RESULTS Executive abilities were particularly compromised in the participants with DM2. Furthermore, the DM2 group exhibited reduced postural stability under dual task conditions. DISCUSSION These findings suggest that deficits in more complex cognitive activities underlie the decline in everyday function in DM2.
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Affiliation(s)
| | - Jane E Else
- Northumbria University, Newcastle upon Tyne, UK
| | | | - Jonathan K Foster
- Curtin University, Perth, Western Australia, Australia Government of Western Australia Department of Health, Perth, Australia University of Western Australia, Perth, Australia
| | - Mark Walker
- Newcastle University, Newcastle upon Tyne, UK
| | - Keith A Wesnes
- Northumbria University, Newcastle upon Tyne, UK Bracket Global, Goring on Thames, UK
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183
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Lee JH, Choi Y, Jun C, Hong YS, Cho HB, Kim JE, Lyoo IK. Neurocognitive changes and their neural correlates in patients with type 2 diabetes mellitus. Endocrinol Metab (Seoul) 2014; 29:112-21. [PMID: 25031883 PMCID: PMC4091490 DOI: 10.3803/enm.2014.29.2.112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
As the prevalence and life expectancy of type 2 diabetes mellitus (T2DM) continue to increase, the importance of effective detection and intervention for the complications of T2DM, especially neurocognitive complications including cognitive dysfunction and dementia, is receiving greater attention. T2DM is thought to influence cognitive function through an as yet unclear mechanism that involves multiple factors such as hyperglycemia, hypoglycemia, and vascular disease. Recent developments in neuroimaging methods have led to the identification of potential neural correlates of T2DM-related neurocognitive changes, which extend from structural to functional and metabolite alterations in the brain. The evidence indicates various changes in the T2DM brain, including global and regional atrophy, white matter hyperintensity, altered functional connectivity, and changes in neurometabolite levels. Continued neuroimaging research is expected to further elucidate the underpinnings of cognitive decline in T2DM and allow better diagnosis and treatment of the condition.
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Affiliation(s)
- Junghyun H Lee
- College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, Korea
- Ewha Brain Institute, Ewha Womans University, Seoul, Korea
| | - Yera Choi
- Ewha Brain Institute, Ewha Womans University, Seoul, Korea
- Interdisciplinary Program in Neuroscience, Seoul National University College of Natural Sciences, Seoul, Korea
| | - Chansoo Jun
- College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, Korea
- Ewha Brain Institute, Ewha Womans University, Seoul, Korea
| | - Young Sun Hong
- Ewha Brain Institute, Ewha Womans University, Seoul, Korea
- Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea
| | - Han Byul Cho
- Ewha Brain Institute, Ewha Womans University, Seoul, Korea
- Interdisciplinary Program in Neuroscience, Seoul National University College of Natural Sciences, Seoul, Korea
| | - Jieun E Kim
- Ewha Brain Institute, Ewha Womans University, Seoul, Korea
- Department of Brain and Cognitive Sciences, Ewha Womans University Graduate School, Seoul, Korea
| | - In Kyoon Lyoo
- College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, Korea
- Ewha Brain Institute, Ewha Womans University, Seoul, Korea
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184
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Chen YC, Jiao Y, Cui Y, Shang SA, Ding J, Feng Y, Song W, Ju SH, Teng GJ. Aberrant brain functional connectivity related to insulin resistance in type 2 diabetes: a resting-state fMRI study. Diabetes Care 2014; 37:1689-96. [PMID: 24658392 DOI: 10.2337/dc13-2127] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Type 2 diabetes is characterized by insulin resistance, which is involved in the development of Alzheimer disease. This study aims to investigate the relationship between abnormal resting-state brain functional connectivity and insulin resistance in type 2 diabetes. RESEARCH DESIGN AND METHODS A total of 30 patients with type 2 diabetes and 31 healthy well-matched volunteers were prospectively examined. Resting-state brain functional connectivity analysis was used to examine the correlation between the posterior cingulate cortex (PCC) and whole-brain regions. The possible relationships between functional connectivity measures and insulin resistance were evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR). RESULTS Compared with healthy controls, we observed significantly decreased functional connectivity of the PCC within some selected regions, including the right middle temporal gyrus (MTG), left lingual gyrus, left middle occipital gyrus, and left precentral gyrus; increased functional connectivity of the PCC was detected in the left cerebellum posterior lobe, right superior frontal gyrus, and right middle frontal gyrus. A significant negative correlation was found between the PCC-right MTG connectivity and HOMA-IR in type 2 diabetic patients (P = 0.014; r = -0.446). CONCLUSIONS Type 2 diabetic patients develop aberrant functional connectivity of the PCC, which is associated with insulin resistance in selected brain regions. Resting-state connectivity disturbance of PCC-MTG may be a central role for evaluating the cognitive dysfunction in type 2 diabetes.
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Affiliation(s)
- Yu-Chen Chen
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Yun Jiao
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Ying Cui
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Song-An Shang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Jie Ding
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Yuan Feng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Wen Song
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Sheng-Hong Ju
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
| | - Gao-Jun Teng
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China
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185
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Morris JK, Vidoni ED, Perea RD, Rada R, Johnson DK, Lyons K, Pahwa R, Burns JM, Honea RA. Insulin resistance and gray matter volume in neurodegenerative disease. Neuroscience 2014; 270:139-47. [PMID: 24735819 DOI: 10.1016/j.neuroscience.2014.04.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 04/01/2014] [Accepted: 04/02/2014] [Indexed: 02/08/2023]
Abstract
The goal of this study was to compare insulin resistance in aging and aging-related neurodegenerative diseases, and to determine the relationship between insulin resistance and gray matter volume (GMV) in each cohort using an unbiased, voxel-based approach. Insulin resistance was estimated in apparently healthy elderly control (HC, n=21) and neurodegenerative disease (Alzheimer's disease (AD), n=20; Parkinson's disease (PD), n=22) groups using Homeostasis Model Assessment of Insulin Resistance 2 (HOMA2) and intravenous glucose tolerance test (IVGTT). HOMA2 and GMV were assessed within groups through General Linear Model multiple regression. We found that HOMA2 was increased in both AD and PD compared to the HC group (HC vs. AD, p=0.002, HC vs. PD, p=0.003), although only AD subjects exhibited increased fasting glucose (p=0.005). Furthermore, our voxel-based morphometry analysis revealed that HOMA2 was related to GMV in all cohorts in a region-specific manner (p<0.001, uncorrected). Significant relationships were observed in the medial prefrontal cortex (HC), medial temporal regions (AD), and parietal regions (PD). Finally, the directionality of the relationship between HOMA2 and GMV was disease-specific. Both HC and AD subjects exhibited negative relationships between HOMA2 and brain volume (increased HOMA2 associated with decreased brain volume), while a positive relationship was observed in PD. This cross-sectional study suggests that insulin resistance is increased in neurodegenerative disease, and that individuals with AD appear to have more severe metabolic dysfunction than individuals with PD or PD dementia.
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Affiliation(s)
- J K Morris
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States; Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, United States.
| | - E D Vidoni
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States; Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, United States.
| | - R D Perea
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States; Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, United States.
| | - R Rada
- Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, United States.
| | - D K Johnson
- Department of Psychology, University of Kansas, Lawrence, KS, United States.
| | - K Lyons
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States.
| | - R Pahwa
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States.
| | - J M Burns
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States; Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, United States.
| | - R A Honea
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States; Alzheimer's Disease Center, University of Kansas Medical Center, Kansas City, KS, United States.
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186
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Qiu C, Sigurdsson S, Zhang Q, Jonsdottir MK, Kjartansson O, Eiriksdottir G, Garcia ME, Harris TB, van Buchem MA, Gudnason V, Launer LJ. Diabetes, markers of brain pathology and cognitive function: the Age, Gene/Environment Susceptibility-Reykjavik Study. Ann Neurol 2014; 75:138-46. [PMID: 24243491 DOI: 10.1002/ana.24063] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/04/2013] [Accepted: 11/08/2013] [Indexed: 12/21/2022]
Abstract
OBJECTIVE We investigated whether, and the extent to which, vascular and degenerative lesions in the brain mediate the association of diabetes with poor cognitive performance. METHODS This cross-sectional study included 4,206 participants (age > 65 years; 57.8% women) of the Age, Gene/Environment Susceptibility-Reykjavik Study. Data were collected through interview, clinical examination, psychological testing, and laboratory tests. The composite scores on memory, information-processing speed, and executive function were derived from a cognitive test battery. Markers of cerebral macrovascular (cortical infarcts), microvascular (subcortical infarcts, cerebral microbleeds, and higher white matter lesion volume), and neurodegenerative (lower gray matter, normal white matter, and total brain tissue volumes) processes were assessed on magnetic resonance images. Mediation models were employed to test the mediating effect of brain lesions on the association of diabetes with cognitive performance controlling for potential confounders. RESULTS There were 462 (11.0%) persons with diabetes. Diabetes was significantly associated with lower scores on processing speed and executive function, but not with memory function. Diabetes was significantly associated with all markers of brain pathology. All of these markers were significantly associated with lower scores on memory, processing speed, and executive function. Formal mediation tests suggested that markers of cerebrovascular and degenerative pathology significantly mediated the associations of diabetes with processing speed and executive function. INTERPRETATION Diabetes is associated with poor performance on cognitive tests of information-processing speed and executive function. The association is largely mediated by markers of both neurodegeneration and cerebrovascular disease. Older people with diabetes should be monitored for cognitive problems and brain lesions.
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Affiliation(s)
- Chengxuan Qiu
- Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Bethesda, MD; Aging Research Center, Department of Neurobiology, Care Sciences, and Society, Karolinska Institutet-Stockholm University, Stockholm, Sweden
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187
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Despa F, Decarli C. Amylin: what might be its role in Alzheimer's disease and how could this affect therapy? Expert Rev Proteomics 2014; 10:403-5. [PMID: 24117198 DOI: 10.1586/14789450.2013.841549] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Florin Despa
- Department of Molecular and Biomedical Pharmacology, University of Kentucky, 900 S Limestone, Lexington, KY 40536, USA
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188
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Roberts RO, Knopman DS, Przybelski SA, Mielke MM, Kantarci K, Preboske GM, Senjem ML, Pankratz VS, Geda YE, Boeve BF, Ivnik RJ, Rocca WA, Petersen RC, Jack CR. Association of type 2 diabetes with brain atrophy and cognitive impairment. Neurology 2014; 82:1132-41. [PMID: 24647028 DOI: 10.1212/wnl.0000000000000269] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE We investigated the associations of diabetes and hypertension with imaging biomarkers (markers of neuronal injury and ischemic damage) and with cognition in a population-based cohort without dementia. METHODS Participants (n = 1,437, median age 80 years) were evaluated by a nurse and physician and underwent neuropsychological testing. A diagnosis of cognitively normal, mild cognitive impairment (MCI), or dementia was made by an expert panel. Participants underwent MRI to determine cortical and subcortical infarctions, white matter hyperintensity (WMH) volume, hippocampal volume (HV), and whole brain volume (WBV). The medical records were reviewed for diabetes and hypertension in midlife or later. RESULTS Midlife diabetes was associated with subcortical infarctions (odds ratio, 1.85 [95% confidence interval, 1.09-3.15]; p = 0.02), reduced HV (-4% [-7 to -1.0]; p = 0.01), reduced WBV (-2.9% [-4.1 to -1.6]), and prevalent MCI (odds ratio, 2.08; p = 0.01). The association between diabetes and MCI persisted with adjustment for infarctions and WMH volume but was attenuated after adjustment for WBV (1.60 [0.87-2.95]; p = 0.13) and HV (1.82 [1.00-3.32]; p = 0.05). Midlife hypertension was associated with infarctions and WMH volume and was marginally associated with reduced performance in executive function. Effects of late-life onset of diabetes and hypertension were few. CONCLUSIONS Midlife onset of diabetes may affect late-life cognition through loss of brain volume. Midlife hypertension may affect executive function through ischemic pathology. Late-life onset of these conditions had fewer effects on brain pathology and cognition.
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Affiliation(s)
- Rosebud O Roberts
- From the Division of Epidemiology, Department of Health Sciences Research (R.O.R, M.M.M, Y.E.G., W.A.R., R.C.P.), Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (S.A.P., V.S.P.), and Departments of Neurology (R.O.R., D.S.K., B.F.B., W.A.R., R.C.P.), Radiology (K.K., G.M.P., M.L.S., C.R.J.), and Psychiatry & Psychology (R.J.I.), Mayo Clinic, Rochester, MN; and Departments of Psychiatry & Psychology (Y.E.G.) and Neurology (Y.E.G.), Mayo Clinic, Scottsdale, AZ
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189
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Wang W, Yang L, Tan L, Wu X, Jiang B, Shen X. Arg972 insulin receptor substrate-1 polymorphism and risk and severity of Alzheimer's disease. J Clin Neurosci 2014; 21:1233-7. [PMID: 24589556 DOI: 10.1016/j.jocn.2013.09.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 09/23/2013] [Accepted: 09/25/2013] [Indexed: 02/01/2023]
Abstract
We explored the association between the Arg972 insulin receptor substrate-1 (IRS1) polymorphism and the risk and severity of Alzheimer's disease (AD). We genotyped the Arg972 IRS1 (rs1801278) polymorphism in 1123 pairs of age, sex, body mass index, residence area and education level-matched Han Chinese AD patients and controls. AD severity was assessed with Mini-Mental State Examination (MMSE) scores. The AA (homozygous Arg972 IRS1) and GA (heterozygous Arg972 IRS1) genotypes were associated with an increased risk of AD after adjustment for comorbidities including type 2 diabetes mellitus, coronary heart disease, and hypertension (p<0.001; adjusted odds ratio [OR] 3.93 and 2.90, respectively). The A allele was associated with an increased risk of AD after adjustment for comorbidities (p<0.001; adjusted OR 2.26; 95% confidence interval 1.92-2.80). The percentage of Arg972 IRS1 AA homozygotes was higher in the MMSE score ⩽14 category than in the MMSE score 15-26 category overall and in each age group (p<0.001), while the wild type IRS1 GG homozygotes were predominantly found in the MMSE score 15-26 category overall and in each age group. The GG homozygote group had higher MMSE score than the GA heterozygote group, which in turn had higher MMSE score than the AA homozygote group overall and in each age group (p<0.05). In conclusion, the Arg972 IRS1 polymorphism is an independent risk factor for AD and the A allele has a gene dosage effect on AD severity in Han Chinese. This study adds fresh insights into the pathogenesis of AD.
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Affiliation(s)
- Wei Wang
- Department of Neurology, The Second Xiangya Hospital, Central South University, 139 Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Liang Yang
- Department of Neurosurgery, The Third Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China
| | - Liming Tan
- Department of Neurology, The Second Xiangya Hospital, Central South University, 139 Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Xiaomei Wu
- Department of Neurology, The Second Xiangya Hospital, Central South University, 139 Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Bo Jiang
- Department of Neurology, The Second Xiangya Hospital, Central South University, 139 Renmin Road, Changsha, Hunan 410011, People's Republic of China
| | - Xiangmin Shen
- Department of Neurology, The Second Xiangya Hospital, Central South University, 139 Renmin Road, Changsha, Hunan 410011, People's Republic of China.
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190
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Abstract
Type 2 diabetes mellitus (T2D) and Alzheimer disease (AD) are major public health burdens associated with aging. As the age of the population rapidly increases, a sheer increase in the incidence of these diseases is expected. Research has identified T2D as a risk factor for cognitive impairment and potentially AD, but the neurobiological pathways that are affected are only beginning to be understood. The rapid advances in neuroimaging in the past decade have added significant understanding to how T2D affects brain structure and function and possibly lead to AD. This article provides a review of studies that have utilized structural and functional neuroimaging to identify neural pathways that link T2D to impaired cognitive performance and potentially AD. A primary focus of this article is the potential for neuroimaging to assist in understanding the mechanistic pathways that may provide translational opportunities for clinical intervention.
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Affiliation(s)
- John P. Ryan
- University of Pittsburgh, Department of Psychiatry
- Address correspondence to: John Ryan, Department of Psychiatry, 3811 O’Hara St., Pittsburgh, PA 15213., , Phone: 412-246-5692, Fax: 412-586-9111
| | - David F. Fine
- Geriatric Psychiatry Neuroimaging Lab, University of Pittsburgh
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191
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Gray matter volume abnormalities in type 2 diabetes mellitus with and without mild cognitive impairment. Neurosci Lett 2014; 562:1-6. [PMID: 24434688 DOI: 10.1016/j.neulet.2014.01.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/12/2013] [Accepted: 01/04/2014] [Indexed: 11/18/2022]
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192
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Murray M, Stanley M, Lugar HM, Hershey T. Hippocampal Volume in Type 1 Diabetes. EUROPEAN ENDOCRINOLOGY 2014; 10:14-17. [PMID: 29872458 PMCID: PMC5983091 DOI: 10.17925/ee.2014.10.01.14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 11/12/2013] [Indexed: 01/09/2023]
Abstract
The hippocampus plays an important role in human memory and is known to be vulnerable to extreme hyperglycaemia and hypoglycaemia in animal models of type 1 diabetes. Within humans with type 1 diabetes, exposure to glycaemic extremes has been associated with alterations in hippocampal structure and in memory function, but results are inconsistent. It has been hypothesised that the effects of hypoglycaemia and hyperglycaemia on the hippocampus may depend on when during neurodevelopment these extremes occur, possibly explaining some of these inconsistencies. However, data addressing this concept are limited. We review here the existing literature on this complex topic and suggest future avenues of required research.
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Affiliation(s)
| | | | | | - Tamara Hershey
- Professor, Departments of Psychiatry, Neurology and Radiology, Washington University School of Medicine, St Louis, Missouri, US
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193
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Wang J, Gong B, Zhao W, Tang C, Varghese M, Nguyen T, Bi W, Bilski A, Begum S, Vempati P, Knable L, Ho L, Pasinetti GM. Epigenetic mechanisms linking diabetes and synaptic impairments. Diabetes 2014; 63:645-54. [PMID: 24154559 DOI: 10.2337/db13-1063] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Diabetes is one of the major risk factors for dementia. However, the molecular mechanism underlying the risk of diabetes for dementia is largely unknown. Recent studies revealed that epigenetic modifications may play a role in the pathogenesis of diabetes. We hypothesized that diabetes may cause epigenetic changes in the brain that may adversely affect synaptic function. We found significant elevation in the expression of histone deacetylases (HDACs) class IIa in the brains of diabetic subjects compared with control subjects, and these changes coincide with altered expression of synaptic proteins. In a mouse model of diet-induced type 2 diabetes (T2D), we found that, similar to humans, T2D mice also showed increased expression of HDAC IIa in the brain, and these alterations were associated with increased susceptibility to oligomeric Aβ-induced synaptic impairments in the hippocampal formation and eventually led to synaptic dysfunction. Pharmacological inhibition of HDAC IIa restored synaptic plasticity. Our study demonstrates that diabetes may induce epigenetic modifications affecting neuropathological mechanisms in the brain leading to increased susceptibility to insults associated with neurodegenerative or vascular impairments. Our study provides, for the first time, an epigenetic explanation for the increased risk of diabetic patients developing dementia.
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Affiliation(s)
- Jun Wang
- Department of Neurology, Mount Sinai School of Medicine, New York, NY
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194
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Yau PL, Kluger A, Borod JC, Convit A. Neural substrates of verbal memory impairments in adults with type 2 diabetes mellitus. J Clin Exp Neuropsychol 2014; 36:74-87. [PMID: 24417611 DOI: 10.1080/13803395.2013.869310] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Verbal memory impairment is well documented in type 2 diabetes mellitus (T2DM) but, to date, the neural substrates remain unclear. The present study evaluated verbal memory and ascertained the degree of frontal and temporal lobe involvement in the anticipated verbal memory impairment among adults with T2DM. METHOD Forty-six late-middle-aged and elderly adults with T2DM and 50 age-, sex-, and education-matched adults without T2DM underwent medical evaluation, verbal memory assessment, and brain magnetic resonance imaging (MRI) evaluations. RESULTS As anticipated, participants with T2DM had clear verbal memory impairments. Consistent with prior reports, we found volume reductions restricted to the hippocampus. Our diffusion tensor imaging analysis revealed that participants with T2DM had extensive cerebral gray and white matter microstructural abnormalities predominantly in the left hemisphere, with a larger concentration present in the temporal lobe. In contrast, we uncovered mostly nonspecific microstructural abnormalities in the absence of tissue loss in the frontal lobe. Of great importance, we present the first evidence among participants with T2DM linking verbal memory impairment and compromised microstructural integrity of the left parahippocampal gyrus, a key memory-relevant structure. CONCLUSIONS Our results suggest that the hippocampus and parahippocampal gyrus may be particularly vulnerable to the deleterious effects of T2DM. The parahippocampal gyrus in particular may play a crucial role in the verbal memory impairments frequently reported in T2DM. Future studies should employ methods such as resting state functional magnetic resonance imaging and diffusion tensor imaging tractography to better characterize network connectivity, which may help further characterize the verbal memory impairment frequently reported in T2DM.
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Affiliation(s)
- Po Lai Yau
- a Department of Psychiatry , New York University School of Medicine , New York , NY , USA
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195
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Rathakrishnan BG, Doraiswamy PM, Petrella JR. Science to practice: translating automated brain MRI volumetry in Alzheimer's disease from research to routine diagnostic use in the work-up of dementia. Front Neurol 2014; 4:216. [PMID: 24409168 PMCID: PMC3885875 DOI: 10.3389/fneur.2013.00216] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/23/2013] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - P Murali Doraiswamy
- Department of Psychiatry, Duke Institute for Brain Sciences, Duke University Medical Center , Durham, NC , USA
| | - Jeffrey R Petrella
- Department of Radiology, Duke University Medical Center , Durham, NC , USA
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Lamport DJ, Lawton CL, Mansfield MW, Moulin CA, Dye L. Type 2 diabetes and impaired glucose tolerance are associated with word memory source monitoring recollection deficits but not simple recognition familiarity deficits following water, low glycaemic load, and high glycaemic load breakfasts. Physiol Behav 2014; 124:54-60. [DOI: 10.1016/j.physbeh.2013.10.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 10/23/2013] [Indexed: 11/24/2022]
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Abstract
Growing epidemiologic evidence has suggested that people with diabetes mellitus are at an increased risk for the development of dementia. However, the results for the subtypes of dementia are inconsistent. This review examines the risk of dementia in people with diabetes mellitus, and discusses the possible mechanism underpinning this association. Diabetes mellitus is associated with a 1.5- to 2.5-fold greater risk of dementia among community-dwelling elderly people. Notably, diabetes mellitus is a significant risk factor for not only vascular dementia, but also Alzheimer's disease. The mechanisms underpinning the association are unclear, but it may be multifactorial in nature, involving factors such as cardiovascular risk factors, glucose toxicity, changes in insulin metabolism and inflammation. The optimal management of these risk factors in early life may be important to prevent late-life dementia. Furthermore, novel therapeutic strategies will be needed to prevent or reduce the development of dementia in people with diabetes mellitus.
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Affiliation(s)
- Toshiharu Ninomiya
- The George Institute for Global Health, Sydney University, Level 10, King George V Building, 83-117 Missenden Rd, Camperdown, NSW, 2050, Australia,
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198
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Moran C, Phan TG, Chen J, Blizzard L, Beare R, Venn A, Münch G, Wood AG, Forbes J, Greenaway TM, Pearson S, Srikanth V. Brain atrophy in type 2 diabetes: regional distribution and influence on cognition. Diabetes Care 2013; 36:4036-42. [PMID: 23939539 PMCID: PMC3836136 DOI: 10.2337/dc13-0143] [Citation(s) in RCA: 357] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Type 2 diabetes (T2DM) is associated with brain atrophy and cerebrovascular disease. We aimed to define the regional distribution of brain atrophy in T2DM and to examine whether atrophy or cerebrovascular lesions are feasible links between T2DM and cognitive function. RESEARCH DESIGN AND METHODS This cross-sectional study used magnetic resonance imaging (MRI) scans and cognitive tests in 350 participants with T2DM and 363 participants without T2DM. With voxel-based morphometry, we studied the regional distribution of atrophy in T2DM. We measured cerebrovascular lesions (infarcts, microbleeds, and white matter hyperintensity [WMH] volume) and atrophy (gray matter, white matter, and hippocampal volumes) while blinded to T2DM status. With use of multivariable regression, we examined for mediation or effect modification of the association between T2DM and cognitive measures by MRI measures. RESULTS T2DM was associated with more cerebral infarcts and lower total gray, white, and hippocampal volumes (all P < 0.05) but not with microbleeds or WMH. T2DM-related gray matter loss was distributed mainly in medial temporal, anterior cingulate, and medial frontal lobes, and white matter loss was distributed in frontal and temporal regions. T2DM was associated with poorer visuospatial construction, planning, visual memory, and speed (P ≤ 0.05) independent of age, sex, education, and vascular risk factors. The strength of these associations was attenuated by almost one-half when adjusted for hippocampal and total gray volumes but was unchanged by adjustment for cerebrovascular lesions or white matter volume. CONCLUSIONS Cortical atrophy in T2DM resembles patterns seen in preclinical Alzheimer disease. Neurodegeneration rather than cerebrovascular lesions may play a key role in T2DM-related cognitive impairment.
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199
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Chen Z, Li J, Sun J, Ma L. Brain expansion in patients with type II diabetes following insulin therapy: a preliminary study with longitudinal voxel-based morphometry. J Neuroimaging 2013; 24:484-91. [PMID: 24251692 DOI: 10.1111/jon.12059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/01/2013] [Accepted: 06/13/2013] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE We performed a longitudinal analysis based on magnetic resonance (MR) imaging to investigate the brain structural and perfusion changes caused by insulin therapy in patients with type II diabetes. METHODS High resolution three-dimensional T1-weighted fast spoiled gradient recalled echo images and flow-sensitive alternating inversion recovery (FAIR) images were obtained from 11 patients with type II diabetes before and 1 year after initiation of insulin therapy and 11 normal controls. Brain volume changes were investigated by a longitudinal voxel-based morphometry (VBM), and perfusion changes were evaluated by FAIR imaging between baseline and follow-up data. RESULTS Significant regional gray matter (GM) expansion located in bilateral frontal, parietal, and left occipital lobes, and regional white matter (WM) expansion was shown in left precentral subcortical WM and right angular subcortical WM after insulin therapy (P < .05 with FDR correction). Brain hyperperfusion was detected in bilateral frontal cortex, left occipital cortex, and right temporal cortex after insulin therapy (P < .05). CONCLUSIONS In patients with type II diabetes, brain expansion and hyperperfusion were demonstrated 1 year after initiation of insulin therapy, and insulin therapy could contribute to the brain volume gainment in the patients with type II diabetes.
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Affiliation(s)
- Zhiye Chen
- Department of Radiology, PLA General Hospital, Beijing, China
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Huang HC, Tang D, Xu K, Jiang ZF. Curcumin attenuates amyloid-β-induced tau hyperphosphorylation in human neuroblastoma SH-SY5Y cells involving PTEN/Akt/GSK-3β signaling pathway. J Recept Signal Transduct Res 2013; 34:26-37. [DOI: 10.3109/10799893.2013.848891] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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