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Aziz N, Dash B, Wal P, Kumari P, Joshi P, Wal A. New Horizons in Diabetic Neuropathies: An Updated Review on their Pathology, Diagnosis, Mechanism, Screening Techniques, Pharmacological, and Future Approaches. Curr Diabetes Rev 2024; 20:e201023222416. [PMID: 37867268 DOI: 10.2174/0115733998242299231011181615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/16/2023] [Accepted: 08/25/2023] [Indexed: 10/24/2023]
Abstract
BACKGROUND One of the largest problems for global public health is diabetes mellitus (DM) and its micro and macrovascular consequences. Although prevention, diagnosis, and treatment have generally improved, its incidence is predicted to keep rising over the coming years. Due to the intricacy of the molecular mechanisms, which include inflammation, oxidative stress, and angiogenesis, among others, discovering treatments to stop or slow the course of diabetic complications is still a current unmet need. METHODS The pathogenesis and development of diabetic neuropathies may be explained by a wide variety of molecular pathways, hexosamine pathways, such as MAPK pathway, PARP pathway, oxidative stress pathway polyol (sorbitol) pathway, cyclooxygenase pathway, and lipoxygenase pathway. Although diabetic neuropathies can be treated symptomatically, there are limited options for treating the underlying cause. RESULT Various pathways and screening models involved in diabetic neuropathies are discussed, along with their possible outcomes. Moreover, both medicinal and non-medical approaches to therapy are also explored. CONCLUSION This study highlights the probable involvement of several processes and pathways in the establishment of diabetic neuropathies and presents in-depth knowledge of new therapeutic approaches intended to stop, delay, or reverse different types of diabetic complications.
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Affiliation(s)
- Namra Aziz
- Pranveer Singh Institute of Technology (Pharmacy), Bhauti, Kanpur 209305, UP, India
| | - Biswajit Dash
- Department of Pharmaceutical Technology, School of Medical Sciences, ADAMAS University, Kolkata 700 126, West Bengal, India
| | - Pranay Wal
- Pranveer Singh Institute of Technology (Pharmacy), Bhauti, Kanpur 209305, UP, India
| | - Prachi Kumari
- Pranveer Singh Institute of Technology (Pharmacy), Bhauti, Kanpur 209305, UP, India
| | - Poonam Joshi
- Uttaranchal Institute of Pharmaceutical Sciences, Uttaranchal University, Dehradun 248007, Uttarakhand, India
| | - Ankita Wal
- Pranveer Singh Institute of Technology (Pharmacy), Bhauti, Kanpur 209305, UP, India
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2
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Allen RS, Khayat CT, Feola AJ, Win AS, Grubman AR, Chesler KC, He L, Dixon JA, Kern TS, Iuvone PM, Thule PM, Pardue MT. Diabetic rats with high levels of endogenous dopamine do not show retinal vascular pathology. Front Neurosci 2023; 17:1125784. [PMID: 37034167 PMCID: PMC10073440 DOI: 10.3389/fnins.2023.1125784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/21/2023] [Indexed: 04/11/2023] Open
Abstract
Purpose Limited research exists on the time course of long-term retinal and cerebral deficits in diabetic rodents. Previously, we examined short term (4-8 weeks) deficits in the Goto-Kakizaki (GK) rat model of Type II diabetes. Here, we investigated the long-term (1-8 months) temporal appearance of functional deficits (retinal, cognitive, and motor), retinal vascular pathology, and retinal dopamine levels in the GK rat. Methods In GK rats and Wistar controls, retinal neuronal function (electroretinogram), cognitive function (Y-maze), and motor function (rotarod) were measured at 1, 2, 4, 6, and 8 months of age. In addition, we evaluated retinal vascular function (functional hyperemia) and glucose and insulin tolerance. Retinas from rats euthanized at ≥8 months were assessed for vascular pathology. Dopamine and DOPAC levels were measured via HPLC in retinas from rats euthanized at 1, 2, 8, and 12 months. Results Goto-Kakizaki rats exhibited significant glucose intolerance beginning at 4 weeks and worsening over time (p < 0.001). GK rats also showed significant delays in flicker and oscillatory potential implicit times (p < 0.05 to p < 0.001) beginning at 1 month. Cognitive deficits were observed beginning at 6 months (p < 0.05), but no motor deficits. GK rats showed no deficits in functional hyperemia and no increase in acellular retinal capillaries. Dopamine levels were twice as high in GK vs. Wistar retinas at 1, 2, 8, and 12 months (p < 0.001). Conclusion As shown previously, retinal deficits were detectable prior to cognitive deficits in GK rats. While retinal neuronal function was compromised, retinal vascular pathology was not observed, even at 12+ months. High endogenous levels of dopamine in the GK rat may be acting as an anti-angiogenic and providing protection against vascular pathology.
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Affiliation(s)
- Rachael S. Allen
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Cara T. Khayat
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
| | - Andrew J. Feola
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Alice S. Win
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Allison R. Grubman
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Kyle C. Chesler
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Li He
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, United States
| | - Jendayi A. Dixon
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Timothy S. Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, United States
- Veterans Administration Medical Center Research Service, Cleveland, OH, United States
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, United States
| | - Peter M. Thule
- Section Endocrinology and Metabolism, Atlanta VA Medical Center, Emory University School of Medicine, Decatur, GA, United States
| | - Machelle T. Pardue
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
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3
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Özkan E, Çetin-Taş Y, Şekerdağ E, Yiğit B, Shomalizadeh N, Sapancı S, Ozler C, Kesibi J, Kızılırmak AB, Pekmez M, Yapıcı-Eser H, Zeybel M, Karahüseyinoğlu S, Gürsoy-Özdemir Y. Hyperglycemia with or without insulin resistance triggers different structural changes in brain microcirculation and perivascular matrix. Metab Brain Dis 2023; 38:307-321. [PMID: 36305999 DOI: 10.1007/s11011-022-01100-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/08/2022] [Indexed: 02/03/2023]
Abstract
Both type-1 and type-2 DM are related to an increased risk of cognitive impairment, neurovascular complications, and dementia. The primary triggers for complications are hyperglycemia and concomitant insulin resistance in type-2 DM. However, the diverse mechanisms in the pathogenesis of diabetes-related neurovascular complications and extracellular matrix (ECM) remodeling in type-1 and 2 have not been elucidated yet. Here, we investigated the high fat-high sucrose (HFHS) feeding model and streptozotocin-induced type-1 DM model to study the early effects of hyperglycemia with or without insulin resistance to demonstrate the brain microcirculatory changes, perivascular ECM alterations in histological sections and 3D-reconstructed cleared brain tissues. One of the main findings of this study was robust rarefaction in brain microvessels in both models. Interestingly, the HFHS model leads to widespread non-functional angiogenesis, but the type-1 DM model predominantly in the rostral brain. Rarefaction was accompanied by basement membrane thickening and perivascular collagen accumulation in type-1 DM; more severe blood-brain barrier leakage, and disruption of perivascular ECM organization, mainly of elastin and collagen fibers' structural integrity in the HFHS model. Our results point out that the downstream mechanisms of the long-term vascular complications of hyperglycemia models are structurally distinctive and may have implications for appropriate treatment options.
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Affiliation(s)
- Esra Özkan
- Koç University Research Center for Translational Medicine, Istanbul, Turkey.
- Koç University Hospital, 34010, Zeytinburnu, İstanbul, Turkey.
| | - Yağmur Çetin-Taş
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | - Emine Şekerdağ
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | - Buket Yiğit
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | | | - Selin Sapancı
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | - Ceyda Ozler
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | - Judy Kesibi
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | - Ali B Kızılırmak
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
| | - Murat Pekmez
- Faculty of Science, Istanbul University, Istanbul, Turkey
| | - Hale Yapıcı-Eser
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
- Department of Psychiatry, School of Medicine, Koç University, Istanbul, Turkey
| | - Müjdat Zeybel
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust & University of Nottingham, Nottingham, UK
- Department of Gastroenterology and Hepatology, School of Medicine, Koç University, Istanbul, Turkey
| | - Serçin Karahüseyinoğlu
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
- Department of Histology and Embryology, School of Medicine, Koç University, Istanbul, Turkey
| | - Yasemin Gürsoy-Özdemir
- Koç University Research Center for Translational Medicine, Istanbul, Turkey
- Department of Neurology, School of Medicine, Koç University, Istanbul, Turkey
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Biochemical mechanism underlying the pathogenesis of diabetic retinopathy and other diabetic complications in humans: the methanol-formaldehyde-formic acid hypothesis. Acta Biochim Biophys Sin (Shanghai) 2022; 54:415-451. [PMID: 35607958 PMCID: PMC9828688 DOI: 10.3724/abbs.2022012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Hyperglycemia in diabetic patients is associated with abnormally-elevated cellular glucose levels. It is hypothesized that increased cellular glucose will lead to increased formation of endogenous methanol and/or formaldehyde, both of which are then metabolically converted to formic acid. These one-carbon metabolites are known to be present naturally in humans, and their levels are increased under diabetic conditions. Mechanistically, while formaldehyde is a cross-linking agent capable of causing extensive cytotoxicity, formic acid is an inhibitor of mitochondrial cytochrome oxidase, capable of inducing histotoxic hypoxia, ATP deficiency and cytotoxicity. Chronic increase in the production and accumulation of these toxic one-carbon metabolites in diabetic patients can drive the pathogenesis of ocular as well as other diabetic complications. This hypothesis is supported by a large body of experimental and clinical observations scattered in the literature. For instance, methanol is known to have organ- and species-selective toxicities, including the characteristic ocular lesions commonly seen in humans and non-human primates, but not in rodents. Similarly, some of the diabetic complications (such as ocular lesions) also have a characteristic species-selective pattern, closely resembling methanol intoxication. Moreover, while alcohol consumption or combined use of folic acid plus vitamin B is beneficial for mitigating acute methanol toxicity in humans, their use also improves the outcomes of diabetic complications. In addition, there is also a large body of evidence from biochemical and cellular studies. Together, there is considerable experimental support for the proposed hypothesis that increased metabolic formation of toxic one-carbon metabolites in diabetic patients contributes importantly to the development of various clinical complications.
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5
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Pickering J, Wong R, Al-Salami H, Lam V, Takechi R. Cognitive Deficits in Type-1 Diabetes: Aspects of Glucose, Cerebrovascular and Amyloid Involvement. Pharm Res 2021; 38:1477-1484. [PMID: 34480263 DOI: 10.1007/s11095-021-03100-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/24/2021] [Indexed: 11/28/2022]
Abstract
The evidence shows that individuals with type-1 diabetes mellitus (T1DM) are at greater risk of accelerated cognitive impairment and dementia. Although, to date the mechanisms are largely unknown. An emerging body of literature indicates that dysfunction of cerebral neurovascular network and plasma dyshomeostasis of soluble amyloid-β in association with impaired lipid metabolism are central to the onset and progression of cognitive deficits and dementia. However, the latter has not been extensively considered in T1DM. Therefore, in this review, we summarised the literature concerning altered lipid metabolism and cerebrovascular function in T1DM as an implication for potential pathways leading to cognitive decline and dementia.
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Affiliation(s)
- Justin Pickering
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia
| | - Rachel Wong
- Institute for Resilient Regions, University of Southern Queensland, Springfield Central, QLD, 4300, Australia
| | - Hani Al-Salami
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, WA, 6845, Australia
| | - Virginie Lam
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia.,Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia
| | - Ryu Takechi
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia. .,Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia.
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Mazaika PK, Marzelli M, Tong G, Foland-Ross LC, Buckingham BA, Aye T, Reiss AL. Functional near-infrared spectroscopy detects increased activation of the brain frontal-parietal network in youth with type 1 diabetes. Pediatr Diabetes 2020; 21:515-523. [PMID: 32003523 DOI: 10.1111/pedi.12992] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/16/2020] [Accepted: 01/24/2020] [Indexed: 12/30/2022] Open
Abstract
When considered as a group, children with type 1 diabetes have subtle cognitive deficits relative to neurotypical controls. However, the neural correlates of these differences remain poorly understood. Using functional near-infrared spectroscopy (fNIRS), we investigated the brain functional activations of young adolescents (19 individuals with type 1 diabetes, 18 healthy controls, ages 8-16 years) during a Go/No-Go response inhibition task. Both cohorts had the same performance on the task, but the individuals with type 1 diabetes subjects had higher activations in a frontal-parietal network including the bilateral supramarginal gyri and bilateral rostrolateral prefrontal cortices. The activations in these regions were positively correlated with fewer parent-reported conduct problems (ie, lower Conduct Problem scores) on the Behavioral Assessment System for Children, Second Edition. Lower Conduct Problem scores are characteristic of less rule-breaking behavior suggesting a link between this brain network and better self-control. These findings are consistent with a large functional magnetic resonance imaging (fMRI) study of children with type 1 diabetes using completely different participants. Perhaps surprisingly, the between-group activation results from fNIRS were statistically stronger than the results using fMRI. This pilot study is the first fNIRS investigation of executive function for individuals with type 1 diabetes. The results suggest that fNIRS is a promising functional neuroimaging resource for detecting the brain correlates of behavior in the pediatric clinic.
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Affiliation(s)
- Paul K Mazaika
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research (CIBSR), Stanford University School of Medicine, Stanford, California
| | - Matthew Marzelli
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research (CIBSR), Stanford University School of Medicine, Stanford, California
| | - Gabby Tong
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research (CIBSR), Stanford University School of Medicine, Stanford, California
| | - Lara C Foland-Ross
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research (CIBSR), Stanford University School of Medicine, Stanford, California
| | - Bruce A Buckingham
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Tandy Aye
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research (CIBSR), Stanford University School of Medicine, Stanford, California.,Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Allan L Reiss
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research (CIBSR), Stanford University School of Medicine, Stanford, California.,Department of Pediatrics, Stanford University School of Medicine, Stanford, California.,Department of Radiology, Stanford University School of Medicine, Stanford, California
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7
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Allen RS, Feola A, Motz CT, Ottensmeyer AL, Chesler KC, Dunn R, Thulé PM, Pardue MT. Retinal Deficits Precede Cognitive and Motor Deficits in a Rat Model of Type II Diabetes. Invest Ophthalmol Vis Sci 2019; 60:123-133. [PMID: 30640976 DOI: 10.1167/iovs.18-25110] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the temporal appearance of retinal, cognitive, and motor deficits in Goto-Kakizaki (GK) rats, a spontaneously occurring, polygenic model of type II diabetes. GK rats develop impaired insulin secretion at 2 weeks and fasting hyperglycemia at 4 weeks. Methods In male and female GK rats and Wistar controls, glucose tolerance test (hyperglycemia) and electroretinogram (ERG, retinal function) were performed at 4 and 8 weeks of age. Spectral domain-optical coherence tomography (retinal structure) was assessed at 6 weeks. Spatial alternation (cognitive function) and number of entries (exploratory behavior) were assessed via Y-maze at 4, 5, 6, 7, and 8 weeks. Rotarod (motor function) was performed at 4, 6, and 8 weeks. Results By 4 weeks, the GK rats exhibited significant glucose intolerance (P < 0.001) and retinal deficits, including delays in ERG implicit times (flicker, P < 0.01; oscillatory potentials, P < 0.001). In addition, the GK rats showed greater ERG amplitudes (P < 0.001) and thinner retinas (P < 0.001). At 7 weeks, the GK rats showed deficits in cognitive function (P < 0.001) and exploratory behavior (P < 0.01). However, no motor function deficits were observed by 8 weeks. Interestingly, the male GK rats showed greater hyperglycemia (P < 0.05), but the female rats showed greater ERG delays (P < 0.001). Conclusions In GK rats, retinal function deficits developed prior to cognitive or motor deficits. Future studies will investigate common mechanistic links, long-term functional and vascular changes, and whether early retinal deficits can predict cognitive dysfunction or late-stage retinal disease.
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Affiliation(s)
- Rachael S Allen
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Andrew Feola
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Cara T Motz
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States
| | - Amy L Ottensmeyer
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Kyle C Chesler
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Ryan Dunn
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Peter M Thulé
- Section Endocrinology & Metabolism, Atlanta VA Health Care System & Emory University School of Medicine, Decatur, Georgia, United States
| | - Machelle T Pardue
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
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Umpierrez GE, P Kovatchev B. Glycemic Variability: How to Measure and Its Clinical Implication for Type 2 Diabetes. Am J Med Sci 2018; 356:518-527. [PMID: 30447705 PMCID: PMC6709582 DOI: 10.1016/j.amjms.2018.09.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 09/26/2018] [Accepted: 09/26/2018] [Indexed: 01/05/2023]
Abstract
Glycated hemoglobin A1c (A1C) levels have traditionally been the gold standard for assessing glycemic control and treatment efficacy in patients with type 2 diabetes. However, A1C does not take into account fluctuations in blood glucose levels known as glycemic variability (GV). In recent years, GV has become increasingly clinically relevant, because of a better understanding of the need to reach target A1C while avoiding hypoglycemia. GV relates to both hyperglycemia and hypoglycemia, and has been associated with poorer quality of life. Diabetes treatments targeting multiple pathophysiological mechanisms are most beneficial in controlling A1C and reducing GV. In clinical trials, a number of metrics are used to measure GV, many of which are not well understood in the clinical practice. Until a gold standard metric for GV is established, the variety of measurements available may confound the choice of an optimal treatment for an individual patient.
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Affiliation(s)
- Guillermo E Umpierrez
- Division of Endocrinology, Diabetes, and Metabolism, Emory University School of Medicine, Atlanta, Georgia.
| | - Boris P Kovatchev
- Center for Diabetes Technology, University of Virginia Health System, Charlottesville, Virginia.
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9
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Flores-Gómez AA, de Jesús Gomez-Villalobos M, Flores G. Consequences of diabetes mellitus on neuronal connectivity in limbic regions. Synapse 2018; 73:e22082. [PMID: 30457679 DOI: 10.1002/syn.22082] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/25/2018] [Accepted: 11/15/2018] [Indexed: 12/18/2022]
Abstract
Diabetes mellitus (DM) is characterized by high levels of blood glucose. In recent years, its prevalence has increased, which was 422 million in the world in 2014. In elderly patients, DM is associated with deficits in memory and learning processes. The cognitive deficits lead to dementia. With the development of animal models in DM, it has been possible to better understand quantitative morphological changes in numerous neuronal structures belonging to the limbic system, such as the prefrontal cortex (PFC), the hippocampus and basolateral amygdala (BLA). These structures are in close relationship with processes of memory and learning. Several reports have demonstrated that chronic hyperglycemia reduces spinogenesis and dendritic arborization in the aforementioned regions along with a decline in memory and learning processes, especially in streptozotocin (STZ)-induced diabetic rats. In the present review, we discuss animal models, the effects of chronic hyperglycemia on dendritic morphology of limbic regions and memory and learning processes, the effect on neural transmission in these regions, the pathologic mechanisms involved, and the relevance of dendritic morphology in diabetes. All of this information can help us to have a better understanding of dementia in diabetes mellitus and propose strategies for its prevention and treatment.
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Affiliation(s)
| | | | - Gonzalo Flores
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, México
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10
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Guàrdia-Olmos J, Gudayol-Ferré E, Gallardo-Moreno GB, Martínez-Ricart M, Peró-Cebollero M, González-Garrido AA. Complex systems representing effective connectivity in patients with Type One diabetes mellitus. PLoS One 2018; 13:e0208247. [PMID: 30496324 PMCID: PMC6264830 DOI: 10.1371/journal.pone.0208247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 11/14/2018] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Type 1 diabetes mellitus (T1D) affects the entire cellular network of the organism. Some patients develop cognitive disturbances due to the disease, but several authors have suggested that the brain develops compensatory mechanisms to minimize or prevent neuropsychological decline. The present study aimed to assess the effective connectivity underlying visuospatial working memory performance in young adults diagnosed with T1D using neuroimaging techniques (fMRI). METHODS Fifteen T1D right-handed, young adults with sustained metabolic clinical stability and a control group matched by age, sex, and educational level voluntarily participated. All participants performed 2 visuospatial working memory tasks using a block design within an MRI scanner. Regions of interest and their signal values were obtained. Effective connectivity-by means of structural equations models-was evaluated for each group and task through maximum likelihood estimation, and the model with the best fit was chosen in each case. RESULTS Compared to the control group, the patient group showed a significant reduction in brain activity in the two estimated networks (one for each group and task). The models of effective connectivity showed greater brain connectivity in healthy individuals, as well as a more complex network. T1D patients showed a pattern of connectivity mainly involving the cerebellum and the red nucleus. In contrast, the control group showed a connectivity network predominantly involving brain areas that are typically activated while individuals are performing working memory tasks. CONCLUSION Our results suggest a specific effective connectivity between the cerebellum and the red nucleus in T1D patients during working memory tasks, probably reflecting a compensatory mechanism to fulfill task demands.
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Affiliation(s)
- Joan Guàrdia-Olmos
- Facultat de Psicologia, Universitat de Barcelona, Institut de Neurociències, Institute of Complex Systems (UBICS), Barcelona, Spain
| | - Esteve Gudayol-Ferré
- Facultad de Psicología, Universidad Michoacana de San Nicolás de Hidalgo, Francisco, Michoacán, México
| | | | | | - Maribel Peró-Cebollero
- Facultat de Psicologia, Universitat de Barcelona, Institut de Neurociències, Institute of Complex Systems (UBICS), Barcelona, Spain
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11
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Vitvarová T, Neumann D, Šimáková R, Kremláček J. Neurophysiological Evidence for a Compensatory Activity during a Simple Oddball Task in Adolescents with Type 1 Diabetes Mellitus. J Diabetes Res 2018; 2018:8105407. [PMID: 30116745 PMCID: PMC6079416 DOI: 10.1155/2018/8105407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/11/2018] [Accepted: 06/20/2018] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE The poor metabolic control in type 1 diabetes mellitus (T1D) has a negative impact on the developing brain. Hyperglycemia and glycemic fluctuations disrupt mainly executive functions. To assess a hypothesized deficit of the executive functions, we evaluated visual processing and reaction time in an oddball task. METHODS Oddball visual event-related potentials (ERPs), reaction time, and pattern-reversal visual evoked potentials (VEPs) were examined in a cohort of twenty-two 12- to 18-year-old T1D patients without diabetic retinopathy at normal glycemia and in nineteen 10- to 21-year-old healthy controls. RESULTS The P100 peak time of the VEPs was significantly prolonged in T1D patients compared with the control group (p < 0.017). In contrast to the deteriorated sensory response, the area under the curve of the P3b component of the ERPs was significantly larger (p = 0.035) in patients, while reaction time in the same task did not differ between groups (p = 0.713). CONCLUSIONS The deterioration on a sensory level, enhanced activity during cognitive processing, and balanced behavioral response support the view that neuroplasticity counterbalances the neural impairment by enhanced cognitive processing to achieve normal behavioral performance in T1D adolescents.
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Affiliation(s)
- Tereza Vitvarová
- Department of Pediatrics, University Hospital Hradec Kralove, Faculty of Medicine in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
| | - David Neumann
- Department of Pediatrics, University Hospital Hradec Kralove, Faculty of Medicine in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
| | - Radka Šimáková
- Philosophy Faculty, Palacky University Olomouc, Olomouc, Czech Republic
| | - Jan Kremláček
- Department of Pathological Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic
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12
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An inhibitor of soluble epoxide hydrolase ameliorates diabetes-induced learning and memory impairment in rats. Prostaglandins Other Lipid Mediat 2018; 136:84-89. [PMID: 29751149 DOI: 10.1016/j.prostaglandins.2018.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/29/2018] [Accepted: 05/07/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND Pharmacological inhibition of soluble epoxide hydrolase (sEH) enhances the synaptic function in the CNS and has a protective role in cognitive decline. We hypothesized that the sEH inhibitor TPPU might prevent the diabetes-induced decline in learning and memory which is associated with an alteration in the level of neurotransmitters and oxidative stress. METHODS Type 1 diabetes was induced in rats and the animals were treated with TPPU for 8 weeks. The learning and memory functions were assessed by the Barnes maze and a step-down test. Indicators of oxidative stress, levels of neurotransmitters, and activity of acetylcholinesterase were measured in the discrete regions of the brain. RESULTS Our results revealed that treatment with TPPU significantly improves learning and memory performance in diabetic rats along with decreasing the level of blood sugar. Moreover, treatment with TPPU significantly prevented the diabetes-induced alteration in levels of neurotransmitters, the activity of acetylcholinesterase and preserved anti-oxidant defence system. CONCLUSION Inhibition of the sEH alleviates diabetes-induced decline in learning and memory.
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13
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Allen RS, Hanif AM, Gogniat MA, Prall BC, Haider R, Aung MH, Prunty MC, Mees LM, Coulter MM, Motz CT, Boatright JH, Pardue MT. TrkB signalling pathway mediates the protective effects of exercise in the diabetic rat retina. Eur J Neurosci 2018. [PMID: 29537701 DOI: 10.1111/ejn.13909] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Diabetic retinopathy is a leading cause of vision loss. Treatment options for early retinopathy are sparse. Exercise protects dying photoreceptors in models of retinal degeneration, thereby preserving vision. We tested the protective effects of exercise on retinal and cognitive deficits in a type 1 diabetes model and determined whether the TrkB pathway mediates this effect. Hyperglycaemia was induced in Long Evans rats via streptozotocin injection (STZ; 100 mg/kg). Following confirmed hyperglycaemia, both control and diabetic rats underwent treadmill exercise for 30 min, 5 days/week at 0 m/min (inactive groups) or 15 m/min (active groups) for 8 weeks. A TrkB receptor antagonist (ANA-12), or vehicle, was injected 2.5 h before exercise training. We measured spatial frequency and contrast sensitivity using optokinetic tracking biweekly post-STZ; retinal function using electroretinography at 4 and 8 weeks; and cognitive function and exploratory behaviour using Y-maze at 8 weeks. Retinal neurotrophin-4 was measured using ELISA. Compared with non-diabetic controls, diabetic rats showed significantly reduced spatial frequency and contrast sensitivity, delayed electroretinogram oscillatory potential and flicker implicit times and reduced cognitive function and exploratory behaviour. Exercise interventions significantly delayed the appearance of all deficits, except for exploratory behaviour. Treatment with ANA-12 significantly reduced this protection, suggesting a TrkB-mediated mechanism. Despite this, no changes in retinal neurotrohin-4 were observed with diabetes or exercise. Exercise protected against early visual and cognitive dysfunction in diabetic rats, suggesting that exercise interventions started after hyperglycaemia diagnosis may be a beneficial treatment. The translational potential is high, given that exercise treatment is non-invasive, patient controlled and inexpensive.
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Affiliation(s)
- Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Adam M Hanif
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA
| | - Marissa A Gogniat
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA.,Department of Ophthalmology, Emory University, Atlanta, GA, USA
| | - Brian C Prall
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA.,Department of Ophthalmology, Emory University, Atlanta, GA, USA.,Neuroscience Program, Emory University, Atlanta, GA, USA
| | - Raza Haider
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA
| | - Moe H Aung
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA.,Department of Ophthalmology, Emory University, Atlanta, GA, USA.,Neuroscience Program, Emory University, Atlanta, GA, USA
| | - Megan C Prunty
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA
| | - Lukas M Mees
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA.,Department of Ophthalmology, Emory University, Atlanta, GA, USA
| | - Monica M Coulter
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA
| | - Cara T Motz
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA
| | - Jeffrey H Boatright
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA.,Department of Ophthalmology, Emory University, Atlanta, GA, USA.,Neuroscience Program, Emory University, Atlanta, GA, USA
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA, 30033, USA.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,Neuroscience Program, Emory University, Atlanta, GA, USA
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14
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Hosseini SMH, Mazaika P, Mauras N, Buckingham B, Weinzimer SA, Tsalikian E, White NH, Reiss AL. Altered Integration of Structural Covariance Networks in Young Children With Type 1 Diabetes. Hum Brain Mapp 2018; 37:4034-4046. [PMID: 27339089 DOI: 10.1002/hbm.23293] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 05/24/2016] [Accepted: 06/12/2016] [Indexed: 02/05/2023] Open
Abstract
Type 1 diabetes mellitus (T1D), one of the most frequent chronic diseases in children, is associated with glucose dysregulation that contributes to an increased risk for neurocognitive deficits. While there is a bulk of evidence regarding neurocognitive deficits in adults with T1D, little is known about how early-onset T1D affects neural networks in young children. Recent data demonstrated widespread alterations in regional gray matter and white matter associated with T1D in young children. These widespread neuroanatomical changes might impact the organization of large-scale brain networks. In the present study, we applied graph-theoretical analysis to test whether the organization of structural covariance networks in the brain for a cohort of young children with T1D (N = 141) is altered compared to healthy controls (HC; N = 69). While the networks in both groups followed a small world organization-an architecture that is simultaneously highly segregated and integrated-the T1D network showed significantly longer path length compared with HC, suggesting reduced global integration of brain networks in young children with T1D. In addition, network robustness analysis revealed that the T1D network model showed more vulnerability to neural insult compared with HC. These results suggest that early-onset T1D negatively impacts the global organization of structural covariance networks and influences the trajectory of brain development in childhood. This is the first study to examine structural covariance networks in young children with T1D. Improving glycemic control for young children with T1D might help prevent alterations in brain networks in this population. Hum Brain Mapp 37:4034-4046, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- S M Hadi Hosseini
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research, Stanford University, Stanford, California.
| | - Paul Mazaika
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research, Stanford University, Stanford, California
| | - Nelly Mauras
- Division of Endocrinology, Nemours Children's Health System, Jacksonville, Florida
| | - Bruce Buckingham
- Division of Pediatric Endocrinology, Stanford University, Stanford, California
| | - Stuart A Weinzimer
- Division of Pediatric Endocrinology, Yale University, New Haven, Connecticut
| | - Eva Tsalikian
- Division of Pediatric Endocrinology, University of Iowa, Iowa City, Iowa
| | - Neil H White
- Department of Pediatrics, Washington University, St. Louis, Missouri
| | - Allan L Reiss
- Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research, Stanford University, Stanford, California
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15
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Guàrdia-Olmos J, Gallardo-Moreno GB, Gudayol-Ferré E, Peró-Cebollero M, González-Garrido AA. Effect of verbal task complexity in a working memory paradigm in patients with type 1 diabetes. A fMRI study. PLoS One 2017; 12:e0178172. [PMID: 28582399 PMCID: PMC5459425 DOI: 10.1371/journal.pone.0178172] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 05/08/2017] [Indexed: 12/12/2022] Open
Abstract
Type 1 diabetes (T1D) is commonly diagnosed in childhood and adolescence, and the developing brain has to cope with its deleterious effects. Although brain adaptation to the disease may not result in evident cognitive dysfunction, the effects of T1D on neurodevelopment could alter the pattern of BOLD fMRI activation. The aim of this study was to explore the neural BOLD activation pattern in patients with T1D versus that of healthy matched controls while performing two visuospatial working memory tasks, which included a pair of assignments administered through a block design. In the first task (condition A), the subjects were shown a trial sequence of 3 or 4 white squares positioned pseudorandomly around a fixation point on a black background. After a fixed delay, a second corresponding sequence of 3 or 4 red squares was shown that either resembled (direct, 50%) or differed from (50%) the previous stimulation order. The subjects were required to press one button if the two spatial sequences were identical or a second button if they were not. In condition B, the participants had to determine whether the second sequence of red squares appeared in inverse order (inverse, 50%) or not (50%) and respond by pressing a button. If the latter sequence followed an order distinct from the inverse sequence, the subjects were instructed to press a different button. Sixteen patients with normal IQ and without diabetes complications and 16 healthy control subjects participated in the study. In the behavioral analysis, there were no significant differences between the groups in the pure visuo-spatial task, but the patients with diabetes exhibited poorer performance in the task with verbal stimuli (p < .001). However, fMRI analyses revealed that the patients with T1D showed significantly increased activation in the prefrontal inferior cortex, subcortical regions and the cerebellum (in general p < .001). These different activation patterns could be due to adaptive compensation mechanisms that are devoted to improving efficiency while solving more complex cognitive tasks.
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Affiliation(s)
- Joan Guàrdia-Olmos
- Facultat de Psicologia, Universitat de Barcelona, Institut de Neurociències. Institute of Complex Systems (UBICS), Passeig de la Vall d’Hebron 171, Barcelona, Spain
| | - Geisa B. Gallardo-Moreno
- Instituto de Neurociencias, Universidad de Guadalajara, Francisco de Quevedo 180, Colonia Arcos Vallarta, Guadalajara, Jalisco, Mexico
| | - Esteve Gudayol-Ferré
- Facultad de Psicología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, Mexico
| | - Maribel Peró-Cebollero
- Facultat de Psicologia, Universitat de Barcelona, Institut de Neurociències. Institute of Complex Systems (UBICS), Passeig de la Vall d’Hebron 171, Barcelona, Spain
| | - Andrés A. González-Garrido
- Instituto de Neurociencias, Universidad de Guadalajara, Francisco de Quevedo 180, Colonia Arcos Vallarta, Guadalajara, Jalisco, Mexico
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16
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Rooijackers HMM, Wiegers EC, Tack CJ, van der Graaf M, de Galan BE. Brain glucose metabolism during hypoglycemia in type 1 diabetes: insights from functional and metabolic neuroimaging studies. Cell Mol Life Sci 2016; 73:705-22. [PMID: 26521082 PMCID: PMC4735263 DOI: 10.1007/s00018-015-2079-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 10/16/2015] [Accepted: 10/20/2015] [Indexed: 12/30/2022]
Abstract
Hypoglycemia is the most frequent complication of insulin therapy in patients with type 1 diabetes. Since the brain is reliant on circulating glucose as its main source of energy, hypoglycemia poses a threat for normal brain function. Paradoxically, although hypoglycemia commonly induces immediate decline in cognitive function, long-lasting changes in brain structure and cognitive function are uncommon in patients with type 1 diabetes. In fact, recurrent hypoglycemia initiates a process of habituation that suppresses hormonal responses to and impairs awareness of subsequent hypoglycemia, which has been attributed to adaptations in the brain. These observations sparked great scientific interest into the brain's handling of glucose during (recurrent) hypoglycemia. Various neuroimaging techniques have been employed to study brain (glucose) metabolism, including PET, fMRI, MRS and ASL. This review discusses what is currently known about cerebral metabolism during hypoglycemia, and how findings obtained by functional and metabolic neuroimaging techniques contributed to this knowledge.
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Affiliation(s)
- Hanne M M Rooijackers
- Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
| | - Evita C Wiegers
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Cees J Tack
- Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Marinette van der Graaf
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Bastiaan E de Galan
- Department of Internal Medicine 463, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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17
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Toprak H, Yetis H, Alkan A, Filiz M, Kurtcan S, Aralasmak A, Aksu MŞ, Cesur Y. Relationships of DTI findings with neurocognitive dysfunction in children with Type 1 diabetes mellitus. Br J Radiol 2016; 89:20150680. [PMID: 26728951 DOI: 10.1259/bjr.20150680] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE To determine whether there were diffusion tensor imaging (DTI) changes in the brain among children with Type 1 diabetes mellitus (DM) and investigate the correlation between the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and neurocognitive functions. METHODS 35 children with Type 1 DM and 21 age-matched healthy control subjects were included. Neurocognitive functions of subjects with Type 1 DM were evaluated. In both groups, FA and ADC values were calculated in 20 different locations. The association between neurocognitive function tests and FA and ADC values was investigated. RESULTS Subjects with diabetes had significant changes in FA and ADC values in widespread brain regions compared with the healthy control group. ADC values in the caudate nucleus were negatively associated with verbal point. Increased ADC values in the genu of the corpus callosum were positively associated with Stroop test. There was a negative correlation between the ADC values of the parietal white matter and the judgment of line orientation test. FA values of the inferior longitudinal fasciculus were positively correlated with performance point. However, a negative correlation was noted between FA values of mid-brain and intelligence quotient level as well as another negative correlation between FA values of the posterior crus of the internal capsule and thalamus with verbal point. CONCLUSION Subjects with diabetes demonstrated significant changes in FA and ADC values in widespread brain regions, and such changes could be early features of injury to myelinated fibres or axonal degeneration. Our findings suggest that brain damage may have begun at the cellular level in the initial stage of Type 1 diabetes and neurocognitive impairments may be inevitable. ADVANCES IN KNOWLEDGE DTI can demonstrate ADC and FA changes which are well correlated with neurocognitive dysfunction in the brains of children with Type 1 DM. This may help us in guiding preventive measures in early period of the disease before deterioration of neurocognitive functions.
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Affiliation(s)
- Huseyin Toprak
- 1 Department of Radiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Huseyin Yetis
- 1 Department of Radiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Alpay Alkan
- 1 Department of Radiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Mekiya Filiz
- 2 Department of Child Psychology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Serpil Kurtcan
- 1 Department of Radiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Ayşe Aralasmak
- 1 Department of Radiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Mehmet Ş Aksu
- 3 Department of Pediatric Endocrinology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Yaşar Cesur
- 3 Department of Pediatric Endocrinology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
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18
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Hwang M, Tudorascu DL, Nunley K, Karim H, Aizenstein HJ, Orchard TJ, Rosano C. Brain Activation and Psychomotor Speed in Middle-Aged Patients with Type 1 Diabetes: Relationships with Hyperglycemia and Brain Small Vessel Disease. J Diabetes Res 2016; 2016:9571464. [PMID: 26998494 PMCID: PMC4779538 DOI: 10.1155/2016/9571464] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 01/26/2023] Open
Abstract
Slower psychomotor speed is very common in patients with type 1 diabetes mellitus (T1D), but the underlying mechanisms are not clear. We propose that hyperglycemia is associated with slower psychomotor speed via disruption of brain activation. Eighty-five adults (48% women, mean age: 49.0 years, mean duration: 40.8) with childhood onset T1D were recruited for this cross-sectional study. Median response time in seconds (longer = worse performance) and brain activation were measured while performing a psychomotor speed task. Exposure to hyperglycemia, measured as glycosylated hemoglobin A1c, was associated with longer response time and with higher activation in the inferior frontal gyrus and primary sensorimotor and dorsal cingulate cortex. Higher activation in inferior frontal gyrus, primary sensorimotor cortex, thalamus, and cuneus was related to longer response times; in contrast, higher activation in the superior parietal lobe was associated with shorter response times. Associations were independent of small vessel disease in the brain or other organs. In this group of middle-aged adults with T1D, the pathway linking chronic hyperglycemia with slower processing speed appears to include increased brain activation, but not small vessel disease. Activation in the superior parietal lobe may compensate for dysregulation in brain activation in the presence of hyperglycemia.
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Affiliation(s)
- Misun Hwang
- Department of Radiology, University of Pittsburgh, 3600 Forbes Avenue, Plaza Level, Pittsburgh, PA 15213, USA
| | - Dana L. Tudorascu
- Department of Internal Medicine, Department of Psychiatry, and Department of Biostatistics, University of Pittsburgh, 200 Meyran Avenue, Suite 326, Pittsburgh, PA 15213, USA
| | - Karen Nunley
- Department of Epidemiology, University of Pittsburgh, 130 N. Bellefield Avenue, Suite 443, Pittsburgh, PA 15213, USA
| | - Helmet Karim
- Department of Bioengineering, University of Pittsburgh, 253 Sterling Plaza, Pittsburgh, PA 15213, USA
| | - Howard J. Aizenstein
- Department of Psychiatry, University of Pittsburgh, 3811 O'Hara Street, Pittsburgh, PA 15213, USA
| | - Trevor J. Orchard
- Department of Epidemiology, University of Pittsburgh, 3512 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Caterina Rosano
- Department of Epidemiology, University of Pittsburgh, 130 N. Bellefield Avenue, Suite 467, Pittsburgh, PA 15213, USA
- *Caterina Rosano:
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19
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He XS, Wang ZX, Zhu YZ, Wang N, Hu X, Zhang DR, Zhu DF, Zhou JN. Hyperactivation of working memory-related brain circuits in newly diagnosed middle-aged type 2 diabetics. Acta Diabetol 2015; 52:133-42. [PMID: 24993663 PMCID: PMC4416650 DOI: 10.1007/s00592-014-0618-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 06/16/2014] [Indexed: 01/21/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is well known for its adverse impacts on brain and cognition, which leads to multidimensional cognitive deficits and wildly spread cerebral structure abnormalities. However, existing literatures are mainly focused on patients with advanced age or extended T2DM duration. Therefore, it remains unclear whether and how brain function would be affected at the initial onset stage of T2DM in relatively younger population. In current study, twelve newly diagnosed middle-aged T2DM patients with no previous diabetic treatment history and twelve matched controls were recruited. Brain activations during a working memory task, the digit n-back paradigm (0-, 1- and 2-back), were obtained with functional magnetic resonance imaging and tested by repeated measures ANOVA. Whereas patients performed the n-back task comparably well as controls, significant load-by-group interactions of brain activation were found in the right dorsolateral prefrontal cortex (DLPFC), left middle/inferior frontal gyrus, and left parietal cortex, where patients exhibited hyperactivation in the 2-back, but not the 0-back or 1-back condition compared to controls. Furthermore, the severity of chronic hyperglycemia, estimated by glycosylated hemoglobin (HbA1c) level, was entered into partial correlational analyses with task-related brain activations, while controlling for the real-time influence of glucose, estimated by instant plasma glucose level measured before scanning. Significant positive correlations were found between HbA1c and brain activations in the anterior cingulate cortex and bilateral DLPFC only in patients. Taken together, these findings suggest there might be a compensatory mechanism due to brain inefficiency related to chronic hyperglycemia at the initial onset stage of T2DM.
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Affiliation(s)
- Xiao-Song He
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Zhao-Xin Wang
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
- Key Laboratory of Brain Functional Genomics (MOE & STCSM), Institute of Cognitive Neuroscience, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China
| | - You-Zhi Zhu
- Department of Radiology, PLA 105 Hospital, Hefei, Anhui, China
| | - Nan Wang
- Department of Endocrinology, Anhui Geriatric Institute, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Xiaoping Hu
- Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, GA, USA
| | - Da-Ren Zhang
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - De-Fa Zhu
- Department of Endocrinology, Anhui Geriatric Institute, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
- Correspondence to: Dr. De-Fa Zhu (Department of Endocrinology, Anhui Geriatric Institute, First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui, China, 230022. ) or Dr. Jiang-Ning Zhou (CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science & Technology of China, 433 Huangshan Road, Hefei, Anhui, China, 230027. )
| | - Jiang-Ning Zhou
- CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
- Correspondence to: Dr. De-Fa Zhu (Department of Endocrinology, Anhui Geriatric Institute, First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui, China, 230022. ) or Dr. Jiang-Ning Zhou (CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science & Technology of China, 433 Huangshan Road, Hefei, Anhui, China, 230027. )
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20
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Gallardo-Moreno GB, González-Garrido AA, Gudayol-Ferré E, Guàrdia-Olmos J. Type 1 Diabetes Modifies Brain Activation in Young Patients While Performing Visuospatial Working Memory Tasks. J Diabetes Res 2015; 2015:703512. [PMID: 26266268 PMCID: PMC4525461 DOI: 10.1155/2015/703512] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 06/30/2015] [Accepted: 07/01/2015] [Indexed: 12/23/2022] Open
Abstract
In recent years, increasing attention has been paid to the effects of Type 1 Diabetes (T1D) on cognitive functions. T1D onset usually occurs during childhood, so it is possible that the brain could be affected during neurodevelopment. We selected young patients of normal intelligence with T1D onset during neurodevelopment, no complications from diabetes, and adequate glycemic control. The purpose of this study was to compare the neural BOLD activation pattern in a group of patients with T1D versus healthy control subjects while performing a visuospatial working memory task. Sixteen patients and 16 matched healthy control subjects participated. There was no significant statistical difference in behavioral performance between the groups, but, in accordance with our hypothesis, results showed distinct brain activation patterns. Control subjects presented the expected activations related to the task, whereas the patients had greater activation in the prefrontal inferior cortex, basal ganglia, posterior cerebellum, and substantia nigra. These different patterns could be due to compensation mechanisms that allow them to maintain a behavioral performance similar to that of control subjects.
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Affiliation(s)
- Geisa B. Gallardo-Moreno
- Instituto de Neurociencias, Universidad de Guadalajara, Francisco de Quevedo 180, Colonia Arcos Vallarta, 44130 Guadalajara, JAL, Mexico
- *Geisa B. Gallardo-Moreno:
| | - Andrés A. González-Garrido
- Instituto de Neurociencias, Universidad de Guadalajara, Francisco de Quevedo 180, Colonia Arcos Vallarta, 44130 Guadalajara, JAL, Mexico
| | - Esteban Gudayol-Ferré
- Facultad de Psicología, Universidad Michoacana de San Nicolás de Hidalgo, Francisco Villa 450, 58120 Morelia, MICH, Mexico
| | - Joan Guàrdia-Olmos
- Facultat de Psicologia, Universitat de Barcelona, Institut de Recerca en Cervell, Cognició i Conducta (IR3C), Passeig de la Vall d'Hebron 171, 08035 Barcelona, Spain
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21
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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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22
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Hypoglycemia induced by insulin as a triggering factor of cognitive deficit in diabetic children. ScientificWorldJournal 2014; 2014:616534. [PMID: 24790575 PMCID: PMC3982249 DOI: 10.1155/2014/616534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Accepted: 02/18/2014] [Indexed: 12/12/2022] Open
Abstract
This paper provides an overview of insulin-induced hypoglycemia as a triggering factor of cognitive deficit in children with type 1 diabetes mellitus. For this purpose, databases from 1961 to 2013 were used with the objective of detecting the primary publications that address the impact of hypoglycemia on cognitive performance of diabetic children. The results obtained from experimental animals were excluded. The majority of studies demonstrated that the cognitive deficit in diabetic children involves multiple factors including duration, intensity, severity, and frequency of hypoglycemia episodes. Additionally, age at the onset of type 1 diabetes also influences the cognitive performance, considering that early inception of the disease is a predisposing factor for severe hypoglycemia. Furthermore, the results suggest that there is a strong correlation between brain damage caused by hypoglycemia and cognitive deterioration. Therefore, a more cautious follow-up and education are needed to impede and treat hypoglycemia in children with diabetes mellitus.
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Hagiwara S, Jha JC, Cooper ME. Identifying and interpreting novel targets that address more than one diabetic complication: a strategy for optimal end organ protection in diabetes. Diabetol Int 2013. [DOI: 10.1007/s13340-013-0148-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Sweet memories: 20 years of progress in research on cognitive functioning in diabetes. Eur J Pharmacol 2013; 719:153-160. [PMID: 23872409 DOI: 10.1016/j.ejphar.2013.04.055] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 03/20/2013] [Accepted: 04/03/2013] [Indexed: 01/27/2023]
Abstract
This paper appears in a special issue of the European Journal of Pharmacology that commemorates the retirement of Professor Willem Hendrik Gispen as distinguished professor of Utrecht University and as editor of the European Journal of Pharmacology. The paper provides an overview of a research line on the impact of diabetes on cognition that we started together 20 years ago, and that continues to this day. I will report how we more or less stumbled upon this topic, that was understudied, but proved to be of definite clinical relevance. I will discuss how we tried to establish animal models, how developments from clinical and experimental studies from around the world led us to reconsider our concepts, and how findings from research on diabetic neuropathy, insulin signaling in the brain, Alzheimer's disease and dementia, and vascular disease and stroke converged and helped to create new ideas and refute others. This voyage has not ended yet, because the ultimate goal is to offer patients with diabetes treatment that can protect them against accelerated cognitive decline. Although this could take another 20 years, the research from Willem Hendrik and his group brought us an important step in the right direction.
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Abstract
It is increasingly apparent that not only is a cure for the current worldwide diabetes epidemic required, but also for its major complications, affecting both small and large blood vessels. These complications occur in the majority of individuals with both type 1 and type 2 diabetes. Among the most prevalent microvascular complications are kidney disease, blindness, and amputations, with current therapies only slowing disease progression. Impaired kidney function, exhibited as a reduced glomerular filtration rate, is also a major risk factor for macrovascular complications, such as heart attacks and strokes. There have been a large number of new therapies tested in clinical trials for diabetic complications, with, in general, rather disappointing results. Indeed, it remains to be fully defined as to which pathways in diabetic complications are essentially protective rather than pathological, in terms of their effects on the underlying disease process. Furthermore, seemingly independent pathways are also showing significant interactions with each other to exacerbate pathology. Interestingly, some of these pathways may not only play key roles in complications but also in the development of diabetes per se. This review aims to comprehensively discuss the well validated, as well as putative mechanisms involved in the development of diabetic complications. In addition, new fields of research, which warrant further investigation as potential therapeutic targets of the future, will be highlighted.
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Affiliation(s)
- Josephine M Forbes
- Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
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Kawamura T, Umemura T, Hotta N. Cognitive impairment in diabetic patients: Can diabetic control prevent cognitive decline? J Diabetes Investig 2012; 3:413-23. [PMID: 24843599 PMCID: PMC4019239 DOI: 10.1111/j.2040-1124.2012.00234.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Accepted: 06/27/2012] [Indexed: 12/30/2022] Open
Abstract
It is well recognized that the prevalence of dementia is higher in diabetic patients than non‐diabetic subjects. The incidence of diabetes has been increasing because of dramatic changes in lifestyles, and combined with longer lifespans as a result of advances in medical technology, this has brought about an increase in the number of elderly diabetic patients. Together, aging and diabetes have contributed to dementia becoming a serious problem. Progression to dementia reduces quality of life, and imposes a burden on both patients themselves and the families supporting them. Therefore, preventing the complication of dementia will become more and more important in the future. Although many mechanisms have been considered for an association between diabetes and cognitive dysfunction, glucose metabolism abnormalities such as hyperglycemia and hypoglycemia, and insulin action abnormalities such as insulin deficiency and insulin resistance can be causes of cognitive impairment. Recent large‐scale longitudinal studies have found an association between glycemic control and cognitive decline, although it is still unclear how cognitive decline might be prevented by good glycemic control. However, at an early stage, it is necessary to detect moderate cognitive dysfunction and try to reduce the risk factors for it, which should result in prevention of dementia, as well as vascular events. In the present review, in addition to outlining an association between diabetes and cognitive function, we discuss how glycemic control and cognitive decline are related.
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Affiliation(s)
- Takahiko Kawamura
- Department of Diabetes and Endocrine Internal Medicine Chubu Rosai Hospital Nagoya Japan ; Center for Preventive Medicine Chubu Rosai Hospital Nagoya Japan
| | | | - Nigishi Hotta
- Department of Diabetes and Endocrine Internal Medicine Chubu Rosai Hospital Nagoya Japan
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Price TO, Eranki V, Banks WA, Ercal N, Shah GN. Topiramate treatment protects blood-brain barrier pericytes from hyperglycemia-induced oxidative damage in diabetic mice. Endocrinology 2012; 153:362-72. [PMID: 22109883 PMCID: PMC3249670 DOI: 10.1210/en.2011-1638] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Diabetes mellitus causes cerebral microvasculature deterioration and cognitive decline. The specialized endothelial cells of cerebral microvasculature comprise the blood-brain barrier, and the pericytes (PC) that are in immediate contact with these endothelial cells are vital for blood-brain barrier integrity. In diabetes, increased mitochondrial oxidative stress is implicated as a mechanism for hyperglycemia-induced PC loss as a prerequisite leading to blood-brain barrier disruption. Mitochondrial carbonic anhydrases (CA) regulate the oxidative metabolism of glucose and thus play an important role in the generation of reactive oxygen species and oxidative stress. We hypothesize that the inhibition of mitochondrial CA would reduce mitochondrial oxidative stress, rescue cerebral PC loss caused by diabetes-induced oxidative stress, and preserve blood-brain barrier integrity. We studied the effects of pharmacological inhibition of mitochondrial CA activity on streptozotocin-diabetes-induced oxidative stress and PC loss in the mouse brain. At 3 wk of diabetes, there was significant oxidative stress; the levels of reduced glutathione were lower and those of 3-nitrotyrosine, 4-hydroxy-2-trans-nonenal, and superoxide dismutase were higher. Treatment of diabetic mice with topiramate, a potent mitochondrial CA inhibitor, prevented the oxidative stress caused by 3 wk of diabetes. A significant decline in cerebral PC numbers, at 12 wk of diabetes, was also rescued by topiramate treatment. These results provide the first evidence that inhibition of mitochondrial CA activity reduces diabetes-induced oxidative stress in the mouse brain and rescues cerebral PC dropout. Thus, mitochondrial CA may provide a new therapeutic target for oxidative stress related illnesses of the central nervous system.
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Affiliation(s)
- Tulin O Price
- Division of Endocrinology, Department of Internal Medicine, Saint Louis University, Edward A. Doisy Research Center, 1100 South Grand Boulevard, St. Louis, Missouri 63104, USA
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Bolo NR, Musen G, Jacobson AM, Weinger K, McCartney RL, Flores V, Renshaw PF, Simonson DC. Brain activation during working memory is altered in patients with type 1 diabetes during hypoglycemia. Diabetes 2011; 60:3256-64. [PMID: 21984582 PMCID: PMC3219930 DOI: 10.2337/db11-0506] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To investigate the effects of acute hypoglycemia on working memory and brain function in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS Using blood oxygen level-dependent (BOLD) functional magnetic resonance imaging during euglycemic (5.0 mmol/L) and hypoglycemic (2.8 mmol/L) hyperinsulinemic clamps, we compared brain activation response to a working-memory task (WMT) in type 1 diabetic subjects (n = 16) with that in age-matched nondiabetic control subjects (n = 16). Behavioral performance was assessed by percent correct responses. RESULTS During euglycemia, the WMT activated the bilateral frontal and parietal cortices, insula, thalamus, and cerebellum in both groups. During hypoglycemia, activation decreased in both groups but remained 80% larger in type 1 diabetic versus control subjects (P < 0.05). In type 1 diabetic subjects, higher HbA(1c) was associated with lower activation in the right parahippocampal gyrus and amygdala (R(2) = 0.45, P < 0.002). Deactivation of the default-mode network (DMN) also was seen in both groups during euglycemia. However, during hypoglycemia, type 1 diabetic patients deactivated the DMN 70% less than control subjects (P < 0.05). Behavioral performance did not differ between glycemic conditions or groups. CONCLUSIONS BOLD activation was increased and deactivation was decreased in type 1 diabetic versus control subjects during hypoglycemia. This higher level of brain activation required by type 1 diabetic subjects to attain the same level of cognitive performance as control subjects suggests reduced cerebral efficiency in type 1 diabetes.
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Affiliation(s)
- Nicolas R Bolo
- Brain Imaging Center, McLean Hospital, Belmont, Massachusetts, USA.
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Ishizawa KT, Kumano H, Sato A, Sakura H, Iwamoto Y. Decreased response inhibition in middle-aged male patients with type 2 diabetes. Biopsychosoc Med 2010; 4:1. [PMID: 20181219 PMCID: PMC2834594 DOI: 10.1186/1751-0759-4-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 02/11/2010] [Indexed: 12/31/2022] Open
Abstract
Background This study was performed to examine whether patients with type 2 diabetes have cognitive deficits associated with the prefrontal cortex (PFC). Methods Twenty-seven middle-aged patients with newly diagnosed type 2 diabetes and 27 healthy controls underwent physical measurements and neuropsychological tasks. Response inhibition, reward prediction, and executive function were assessed by the Go/NoGo task, the reversal and extinction tasks, and the Wisconsin Card Sorting Test (WCST). To examine the interactions of being overweight with diabetes on cognitive performance, performance data were analysed by two-way ANCOVA with diabetes and overweight as factors and age as a covariate. Results Patients with type 2 diabetes showed significantly decreased response inhibition in the Go/NoGo task (discriminability index: P = 0.001). There was an interaction of being overweight with diabetes on reaction time in the Go trials of the Go/NoGo task (P = 0.009). Being overweight was related to retained responses to the presentiment of reward in the extinction task (P = 0.029). The four groups showed normal cognitive performance in the WCST. Conclusions Our results showed that middle-aged, newly diagnosed and medication-free patients with type 2 diabetes have a particular neuropsychological deficit in inhibitory control of impulsive response, which is an independent effect of diabetes apart from being overweight.
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Affiliation(s)
- Kaya T Ishizawa
- Faculty of Human Sciences, Waseda University, 2-579-15 Mikashima, Tokorozawa-shi, Saitama 359-1192, Japan
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Abstract
AbstractDiabetes is a chronic metabolic disease which can lead to numerous complications. One of these disturbances is cognitive function impairment. A group of 62 patients with type 1 and type 2 diabetes. There is a correlation between certain clinical features among diabetic patients and cognitive functions. Negative influence on cognitive functions have a higher level of total cholesterol, a higher level of LDL cholesterol, a lower level of HDL cholesterol concentration in the blood, a higher level of glucose after meals, a higher level of basic insulin dose and insulin dose taken just before the examination, longer duration of the diabetes and a lot of hypoglycemic episodes. There is no influence on cognitive functions from glucose levels before meals, the type of the insulin therapy, or the number of hyperglycemic episodes and value rate of hemoglobin HbA1C.
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Calcutt NA, Cooper ME, Kern TS, Schmidt AM. Therapies for hyperglycaemia-induced diabetic complications: from animal models to clinical trials. Nat Rev Drug Discov 2009; 8:417-29. [PMID: 19404313 PMCID: PMC7097138 DOI: 10.1038/nrd2476] [Citation(s) in RCA: 239] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Diabetic complications — the long-term damage to various organ systems — are a great cause of mortality and morbidity in both type 1 and type 2 diabetes. There are currently few therapeutic options to prevent or ameliorate these complications. High blood glucose levels and the subsequent metabolic consequences of hyperglycaemia are widely considered the primary event that initiates diabetic complications, although there is accumulating evidence that impaired insulin signalling arising from insulin deficiency and insulin resistance may also have a pathogenic role. Vascular dysfunction is a prominent complication of diabetes that is widely held to underlie damage to organ systems such as the macrovasculature, kidneys, eyes and nerves. Other consequences of diabetes, such as dyslipidaemia and hypertension, are key modifiers of vascular injury and act as accelerators of diabetic complications. Numerous pathogenic mechanisms, including increased polyol pathway flux and mitochondrial activity, activation of protein kinase C and NADPH oxidase and signalling through the receptor for advanced glycation end products (RAGE) pathway, seem to form a central pathogenic axis that is common to most, if not all, of the complications of diabetes. These disorders all promote excess production of pro-oxidative molecules. Organ-specific mechanisms, such as diminished growth factor support and repair pathway activation, must also be considered. Few animal models of diabetic complications faithfully reflect the advanced stages of organ pathology seen in humans. Current models can be viewed as potentially illustrating early biochemical and functional disorders of diabetes that ultimately lead to advanced pathology. New animal models are being developed using both a reductionist approach for examining specific gene products of interest and also by combining diverse molecular and physiological risk factors. Control of blood glucose levels and lipids remains the most meaningful approach for preventing diabetic complications. This strategy is likely to be complemented by a diverse range of more focused therapeutics that have emerged from mechanistic studies in animal models and which are currently in clinical development. Some of these, such as those targeting cardiovascular disease, have the potential to affect several diabetic complications, whereas others focus on intervening in organ-specific pathogenic mechanisms. It is probable that combination therapies aimed at the hyperglycaemia-driven pathogenic axis and also at organ-specific disorders will provide the most effective approach to treating the diverse complications of diabetes.
Long-term diabetes increases the likelihood of developing complications such as macrovascular disease, nephropathy, retinopathy and neuropathy. This Review highlights the range of pathologies that are precipitated by hyperglycaemia and discusses recent developments in preclinical and clinical research for each of these complications. Long-term diabetes increases the likelihood of developing secondary damage to numerous systems, and these complications represent a substantial cause of morbidity and mortality. Establishing the causes of diabetes remains the key step towards eradicating the disease, but the prevention and amelioration of diabetic complications is equally important for the millions of individuals who already have the disease or are likely to develop it before prophylaxis or a cure become routinely available. In this Review, we focus on four common complications of diabetes, discuss the range of pathologies that are precipitated by hyperglycaemia and highlight emerging targets for therapeutic intervention.
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Affiliation(s)
- Nigel A Calcutt
- Department of Pathology, University of California, San Diego, La Jolla, California 92093, USA.
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Abstract
The deleterious effects of diabetes mellitus on the retinal, renal, cardiovascular, and peripheral nervous systems are widely acknowledged. Less attention has been given to the effect of diabetes on cognitive function. Both type 1 and type 2 diabetes mellitus have been associated with reduced performance on numerous domains of cognitive function. The exact pathophysiology of cognitive dysfunction in diabetes is not completely understood, but it is likely that hyperglycemia, vascular disease, hypoglycemia, and insulin resistance play significant roles. Modalities to study the effect of diabetes on the brain have evolved over the years, including neurocognitive testing, evoked response potentials, and magnetic resonance imaging. Although much insightful research has examined cognitive dysfunction in patients with diabetes, more needs to be understood about the mechanisms and natural history of this complication in order to develop strategies for prevention and treatment.
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Affiliation(s)
- Christopher T Kodl
- Department of Medicine, Division of Endocrinology and Diabetes, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Artola A. Diabetes-, stress- and ageing-related changes in synaptic plasticity in hippocampus and neocortex — The same metaplastic process? Eur J Pharmacol 2008; 585:153-62. [DOI: 10.1016/j.ejphar.2007.11.084] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Revised: 10/04/2007] [Accepted: 11/15/2007] [Indexed: 10/22/2022]
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Abstract
The deleterious effects of diabetes mellitus on the retinal, renal, cardiovascular, and peripheral nervous systems are widely acknowledged. Less attention has been given to the effect of diabetes on cognitive function. Both type 1 and type 2 diabetes mellitus have been associated with reduced performance on numerous domains of cognitive function. The exact pathophysiology of cognitive dysfunction in diabetes is not completely understood, but it is likely that hyperglycemia, vascular disease, hypoglycemia, and insulin resistance play significant roles. Modalities to study the effect of diabetes on the brain have evolved over the years, including neurocognitive testing, evoked response potentials, and magnetic resonance imaging. Although much insightful research has examined cognitive dysfunction in patients with diabetes, more needs to be understood about the mechanisms and natural history of this complication in order to develop strategies for prevention and treatment.
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Affiliation(s)
- Christopher T Kodl
- Department of Medicine, Division of Endocrinology and Diabetes, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Abstract
Type 1 diabetes has mild effects on cognition that are influenced by age of onset, hyperglycemia, and hypoglycemic episodes. Some of these changes occur quite early in the disease course. Studies using relatively new brain imaging techniques have also shown brain changes in adults and children that appear to be influenced by metabolic abnormalities present in diabetes. Early detections of brain changes may be early indicators of subsequent cognitive abnormalities.
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Affiliation(s)
- Gail Musen
- Joslin Diabetes Center, 1 Joslin Place, Boston, MA 02215, USA.
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Wessels AM, Scheltens P, Barkhof F, Heine RJ. Hyperglycaemia as a determinant of cognitive decline in patients with type 1 diabetes. Eur J Pharmacol 2008; 585:88-96. [PMID: 18396273 DOI: 10.1016/j.ejphar.2007.11.080] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 09/12/2007] [Accepted: 11/14/2007] [Indexed: 12/31/2022]
Abstract
Individuals with type 1 diabetes show mild performance deficits in a range of neuropsychological tests compared to healthy controls, but the mechanisms underlying this cognitive deterioration are still poorly understood. Basically, two diabetes-related mechanisms can be postulated: recurrent severe hypoglycaemia and/or chronic hyperglycaemia. Intensive insulin therapy in type 1 diabetes, resulting in a durable improvement of glycaemic control, has been shown to lower the risk of long-term microvascular and macrovascular complications. The down side of striving for strict glycaemic control is the considerably elevated risk of severe hypoglycaemia, sometimes leading to seizure or coma. While retrospective studies in adult patients with type 1 diabetes have suggested an association between a history of recurrent severe hypoglycaemia and a modest or even severe degree of cognitive impairment, large prospective studies have failed to confirm this association. Only fairly recently, better appreciation of the possible deleterious effects of chronic hyperglycaemia on brain function and structure is emerging. In addition, it can be hypothesized that hyperglycaemia associated microvascular changes in the brain are responsible for the cognitive decline in patients with type 1 diabetes. This review presents various pathophysiological considerations concerning the cognitive decline in patients with type 1 diabetes.
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Affiliation(s)
- Alette M Wessels
- Department of Medical Psychology, VU University Medical Center, Amsterdam, The Netherlands.
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Warren RE, Sommerfield AJ, Greve A, Allen KV, Deary IJ, Frier BM. Moderate hypoglycaemia after learning does not affect memory consolidation and brain activation during recognition in non-diabetic adults. Diabetes Metab Res Rev 2008; 24:247-52. [PMID: 18088081 DOI: 10.1002/dmrr.799] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
INTRODUCTION Some aspects of memory performance are impaired during acute hypoglycaemia. The hippocampus is critical to formation of long-term memory, and may be particularly sensitive to hypoglycaemia. This study examined whether moderate hypoglycaemia occurring after learning would disrupt the consolidation process, and used functional magnetic resonance imaging (fMRI) to identify accompanying changes in brain activation. METHODS Sixteen non-diabetic subjects each underwent two glucose clamp studies. During euglycaemia (4.5 mmol/L), subjects tried to memorize a series of words and a series of pictures of faces. Then, either hypoglycaemia (2.5 mmol/L) was induced for one hour, or euglycaemia was maintained. During subsequent uncontrolled euglycaemia, subjects' recognition of the word and face stimuli was tested, with simultaneous fMRI to measure brain activation during recognition. RESULTS Face identification scores were 67.2% after euglycaemia and 66.9% after hypoglycaemia (p = 0.895). Word identification scores were 78.0 and 77.1% respectively (p = 0.701). Analysis of the fMRI identified two foci where activation was altered after hypoglycaemia compared with euglycaemia, but these were not in regions associated with memory, and were probably statistical artefacts. CONCLUSIONS One hour of hypoglycaemia at 2.5 mmol/L induced 20-40 min after learning did not disrupt memory consolidation. fMRI did not show evidence of altered brain activation after hypoglycaemia. Consolidation may be relatively resistant to hypoglycaemia, or may have been complete before hypoglycaemia was induced. The study was powered to detect a large effect, and provides some reassurance that moderate hypoglycaemia does not cause major disruption of previously learned memories in people with insulin-treated diabetes.
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Chronic smoking and the BOLD response to a visual activation task and a breath hold task in patients with schizophrenia and healthy controls. Neuroimage 2008; 40:1181-94. [PMID: 18289881 DOI: 10.1016/j.neuroimage.2007.12.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Accepted: 12/18/2007] [Indexed: 11/17/2022] Open
Abstract
Many psychiatric patient groups smoke heavily, but little is known regarding the effects of this habit on functional brain imaging results. The present report assesses the effect of chronic smoking on the blood oxygen level-dependent (BOLD) response to a simple visual activation (VA) task and a breath hold (BH) task in patients with schizophrenia. Eight healthy controls and twelve patients with schizophrenia were studied. Half of each group had never smoked and the other half of each group had smoked for more than 10 pack years. Responses to the VA task were assessed in the visual cortex and responses to the BH task were assessed in gray matter generally. There were four fMRI-dependent measures: (1) median percent signal change; (2) activation volume (in voxels); (3) time-to-peak of the impulse response function (IRF); and (4) time-to-trough of the IRF. All measures were tested as dependent variables in an ANCOVA with diagnosis and smoking status as crossed factors and age as a covariate. Heavy smokers had 22% larger percent signal change for the VA task and 50% larger percent signal change for the BH task. Patients had a 40% larger percent signal change for the breath hold task. Other statistically significant effects of smoking history on activation volume and the timing of the brain responses were noted. If replicated, the results may have important implications for fMRI studies comparing groups with markedly different smoking habits, such as studies comparing patients with schizophrenia, 60-90% of whom smoke, and healthy controls, who smoke with a much lower frequency.
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Perantie DC, Wu J, Koller JM, Lim A, Warren SL, Black KJ, Sadler M, White NH, Hershey T. Regional brain volume differences associated with hyperglycemia and severe hypoglycemia in youth with type 1 diabetes. Diabetes Care 2007; 30:2331-7. [PMID: 17575089 DOI: 10.2337/dc07-0351] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Despite interest in the effects of type 1 diabetes on the developing brain, structural brain volumes in youth with this disease have not previously been examined. This study is the first to quantify regional brain volume differences in a large sample of youth with diabetes. RESEARCH DESIGN AND METHODS Magnetic resonance images (MRIs) were acquired from youth with diabetes (n = 108) and healthy sibling control subjects (n = 51) aged 7-17 years. History of severe hypoglycemia was assessed by parent interview and included seizure, loss of consciousness, or requiring assistance to treat. A1C values since diagnosis were obtained from medical records; median A1C was weighted by duration of disease. Voxel-based morphometry was used to determine the relationships of prior hypo- and hyperglycemia to regional grey and white matter volumes across the whole brain. RESULTS No significant differences were found between diabetic and healthy control groups in grey or white matter. However, within the diabetic group, a history of severe hypoglycemia was associated with smaller grey matter volume in the left superior temporal region. Greater exposure to hyperglycemia was associated with smaller grey matter volume in the right cuneus and precuneus, smaller white matter volume in a right posterior parietal region, and larger grey matter volume in a right prefrontal region. CONCLUSIONS Qualitatively different relationships were found between hypo- and hyperglycemia and regional brain volumes in youth with type 1 diabetes. Future studies should investigate whether these differences relate to cognitive function and how these regions are affected by further exposure.
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Affiliation(s)
- Dana C Perantie
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Wessels AM, Rombouts SARB, Remijnse PL, Boom Y, Scheltens P, Barkhof F, Heine RJ, Snoek FJ. Cognitive performance in type 1 diabetes patients is associated with cerebral white matter volume. Diabetologia 2007; 50:1763-9. [PMID: 17546438 DOI: 10.1007/s00125-007-0714-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Accepted: 04/23/2007] [Indexed: 01/16/2023]
Abstract
AIMS/HYPOTHESIS Cognitive performance in type 1 diabetes may be compromised as a result of chronic hyperglycaemia. The aim of this study was to investigate the cognitive functioning of patients with type 1 diabetes (including a subgroup with a microvascular complication) and nondiabetic controls, and to assess the relationship between cognition and cerebral grey and white matter volumes. MATERIALS AND METHODS Twenty-five patients with type 1 diabetes (of whom ten had proliferative retinopathy) and nine nondiabetic controls (matched in terms of sex, age and education) underwent a neuropsychological examination and magnetic resonance imaging of the brain. Fractional brain tissue volumes (tissue volume relative to total intracranial volume) were obtained from each participant. RESULTS Compared with nondiabetic controls, patients with diabetes performed worse on tests measuring speed of information processing and visuoconstruction; patients with microvascular disease performed worse on the former cognitive domain (p = 0.03), whereas patients without complications performed worse on the latter domain (p = 0.01). Patients with a microvascular complication had a significantly smaller white matter volume than nondiabetic controls (p = 0.04), and smaller white matter volume was associated with worse performance on the domains of speed of information processing and attention and executive function. CONCLUSIONS/INTERPRETATION Patients with diabetes demonstrated several subtle neuropsychological deficits, which were found to be related to white matter volume. Since patients with diabetic retinopathy had a smaller white matter volume, this suggests that cognitive decline is at least partly mediated by microvascular disease. This needs to be addressed in future studies.
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Affiliation(s)
- A M Wessels
- Department of Medical Psychology, VU University Medical Centre, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands.
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Jacobson AM, Musen G, Ryan CM, Silvers N, Cleary P, Waberski B, Burwood A, Weinger K, Bayless M, Dahms W, Harth J. Long-term effect of diabetes and its treatment on cognitive function. N Engl J Med 2007; 356:1842-52. [PMID: 17476010 PMCID: PMC2701294 DOI: 10.1056/nejmoa066397] [Citation(s) in RCA: 398] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Long-standing concern about the effects of type 1 diabetes on cognitive ability has increased with the use of therapies designed to bring glucose levels close to the nondiabetic range and the attendant increased risk of severe hypoglycemia. METHODS A total of 1144 patients with type 1 diabetes enrolled in the Diabetes Control and Complications Trial (DCCT) and its follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study were examined on entry to the DCCT (at mean age 27 years) and a mean of 18 years later with the same comprehensive battery of cognitive tests. Glycated hemoglobin levels were measured and the frequency of severe hypoglycemic events leading to coma or seizures was recorded during the follow-up period. We assessed the effects of original DCCT treatment-group assignment, mean glycated hemoglobin values, and frequency of hypoglycemic events on measures of cognitive ability, with adjustment for age at baseline, sex, years of education, length of follow-up, visual acuity, self-reported sensory loss due to peripheral neuropathy, and (to control for the effects of practice) the number of cognitive tests taken in the interval since the start of the DCCT. RESULTS Forty percent of the cohort reported having had at least one hypoglycemic coma or seizure. Neither frequency of severe hypoglycemia nor previous treatment-group assignment was associated with decline in any cognitive domain. Higher glycated hemoglobin values were associated with moderate declines in motor speed (P=0.001) and psychomotor efficiency (P<0.001), but no other cognitive domain was affected. CONCLUSIONS No evidence of substantial long-term declines in cognitive function was found in a large group of patients with type 1 diabetes who were carefully followed for an average of 18 years, despite relatively high rates of recurrent severe hypoglycemia. (ClinicalTrials.gov number, NCT00360893.)
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Bibliography. Current world literature. Diabetes and the endocrine pancreas. Curr Opin Endocrinol Diabetes Obes 2007; 14:170-96. [PMID: 17940437 DOI: 10.1097/med.0b013e3280d5f7e9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Affiliation(s)
- Christopher M Ryan
- University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA.
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Ryan CM. Why is cognitive dysfunction associated with the development of diabetes early in life? The diathesis hypothesis. Pediatr Diabetes 2006; 7:289-97. [PMID: 17054452 DOI: 10.1111/j.1399-5448.2006.00206.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Christopher M Ryan
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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