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Tu L, Bean JC, He Y, Liu H, Yu M, Liu H, Zhang N, Yin N, Han J, Scarcelli NA, Conde KM, Wang M, Li Y, Feng B, Gao P, Cai ZL, Fukuda M, Xue M, Tong Q, Yang Y, Liao L, Xu J, Wang C, He Y, Xu Y. Anoctamin 4 channel currents activate glucose-inhibited neurons in the mouse ventromedial hypothalamus during hypoglycemia. J Clin Invest 2023; 133:e163391. [PMID: 37261917 PMCID: PMC10348766 DOI: 10.1172/jci163391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 05/30/2023] [Indexed: 06/03/2023] Open
Abstract
Glucose is the basic fuel essential for maintenance of viability and functionality of all cells. However, some neurons - namely, glucose-inhibited (GI) neurons - paradoxically increase their firing activity in low-glucose conditions and decrease that activity in high-glucose conditions. The ionic mechanisms mediating electric responses of GI neurons to glucose fluctuations remain unclear. Here, we showed that currents mediated by the anoctamin 4 (Ano4) channel are only detected in GI neurons in the ventromedial hypothalamic nucleus (VMH) and are functionally required for their activation in response to low glucose. Genetic disruption of the Ano4 gene in VMH neurons reduced blood glucose and impaired counterregulatory responses during hypoglycemia in mice. Activation of VMHAno4 neurons increased food intake and blood glucose, while chronic inhibition of VMHAno4 neurons ameliorated hyperglycemia in a type 1 diabetic mouse model. Finally, we showed that VMHAno4 neurons represent a unique orexigenic VMH population and transmit a positive valence, while stimulation of neurons that do not express Ano4 in the VMH (VMHnon-Ano4) suppress feeding and transmit a negative valence. Together, our results indicate that the Ano4 channel and VMHAno4 neurons are potential therapeutic targets for human diseases with abnormal feeding behavior or glucose imbalance.
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Affiliation(s)
- Longlong Tu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Jonathan C. Bean
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Yang He
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Hailan Liu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Meng Yu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Hesong Liu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Nan Zhang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Na Yin
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Junying Han
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Nikolas A. Scarcelli
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Kristine M. Conde
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Mengjie Wang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Yongxiang Li
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Bing Feng
- Brain glycemic and metabolism control department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Peiyu Gao
- Brain glycemic and metabolism control department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Zhao-Lin Cai
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, Texas, USA
| | - Makoto Fukuda
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Mingshan Xue
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- The Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, Texas, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Yongjie Yang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Lan Liao
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Jianming Xu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Chunmei Wang
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Yanlin He
- Brain glycemic and metabolism control department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Yong Xu
- Children’s Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
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Sanchez-Rangel E, Deajon-Jackson J, Hwang JJ. Pathophysiology and management of hypoglycemia in diabetes. Ann N Y Acad Sci 2022; 1518:25-46. [PMID: 36202764 DOI: 10.1111/nyas.14904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the century since the discovery of insulin, diabetes has changed from an early death sentence to a manageable chronic disease. This change in longevity and duration of diabetes coupled with significant advances in therapeutic options for patients has fundamentally changed the landscape of diabetes management, particularly in patients with type 1 diabetes mellitus. However, hypoglycemia remains a major barrier to achieving optimal glycemic control. Current understanding of the mechanisms of hypoglycemia has expanded to include not only counter-regulatory hormonal responses but also direct changes in brain glucose, fuel sensing, and utilization, as well as changes in neural networks that modulate behavior, mood, and cognition. Different strategies to prevent and treat hypoglycemia have been developed, including educational strategies, new insulin formulations, delivery devices, novel technologies, and pharmacologic targets. This review article will discuss current literature contributing to our understanding of the myriad of factors that lead to the development of clinically meaningful hypoglycemia and review established and novel therapies for the prevention and treatment of hypoglycemia.
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Affiliation(s)
- Elizabeth Sanchez-Rangel
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jelani Deajon-Jackson
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Janice Jin Hwang
- Department of Internal Medicine, Section of Endocrinology, Yale University School of Medicine, New Haven, Connecticut, USA.,Division of Endocrinology, Department of Internal Medicine, University of North Carolina - Chapel Hill, Chapel Hill, North Carolina, USA
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3
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Verberne AJM, Mussa BM. Neural control of pancreatic peptide hormone secretion. Peptides 2022; 152:170768. [PMID: 35189258 DOI: 10.1016/j.peptides.2022.170768] [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: 01/24/2022] [Revised: 02/10/2022] [Accepted: 02/12/2022] [Indexed: 11/20/2022]
Abstract
Pancreatic peptide hormone secretion is inextricably linked to maintenance of normal levels of blood glucose. In animals and man, pancreatic peptide hormone secretion is controlled, at least in part, by input from parasympathetic (vagal) premotor neurons that are found principally in the dorsal motor nucleus of the vagus (DMV). Iatrogenic (insulin-induced) hypoglycaemia evokes a homeostatic response commonly referred to as the glucose counter-regulatory response. This homeostatic response is of particular importance in Type 1 diabetes in which episodes of hypoglycaemia are common, debilitating and lead to suboptimal control of blood glucose. Glucagon is the principal counterregulatory hormone but for reasons unknown, its secretion during insulin-induced hypoglycaemia is impaired. Pancreatic parasympathetic neurons are distinguishable electrophysiologically from those that control other (e.g. gastric) functions and are controlled by supramedullary inputs from hypothalamic structures such as the perifornical region. During hypoglycaemia, glucose-sensitive, GABAergic neurons in the ventromedial hypothalamus are inhibited leading to disinhibition of perifornical orexin neurons with projections to the DMV which, in turn, leads to increased secretion of glucagon.
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Affiliation(s)
- Anthony J M Verberne
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia.
| | - Bashair M Mussa
- Basic Medical Science Department, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
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Tu L, Fukuda M, Tong Q, Xu Y. The ventromedial hypothalamic nucleus: watchdog of whole-body glucose homeostasis. Cell Biosci 2022; 12:71. [PMID: 35619170 PMCID: PMC9134642 DOI: 10.1186/s13578-022-00799-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 04/25/2022] [Indexed: 02/06/2023] Open
Abstract
The brain, particularly the ventromedial hypothalamic nucleus (VMH), has been long known for its involvement in glucose sensing and whole-body glucose homeostasis. However, it is still not fully understood how the brain detects and responds to the changes in the circulating glucose levels, as well as brain-body coordinated control of glucose homeostasis. In this review, we address the growing evidence implicating the brain in glucose homeostasis, especially in the contexts of hypoglycemia and diabetes. In addition to neurons, we emphasize the potential roles played by non-neuronal cells, as well as extracellular matrix in the hypothalamus in whole-body glucose homeostasis. Further, we review the ionic mechanisms by which glucose-sensing neurons sense fluctuations of ambient glucose levels. We also introduce the significant implications of heterogeneous neurons in the VMH upon glucose sensing and whole-body glucose homeostasis, in which sex difference is also addressed. Meanwhile, research gaps have also been identified, which necessities further mechanistic studies in future.
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Affiliation(s)
- Longlong Tu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA
| | - Makoto Fukuda
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA
| | - Qingchun Tong
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street #8066, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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Jokiaho AJ, Winchester M, Donovan CM. N-Hydroxyethyl-1-Deoxynojirimycin (Miglitol) Restores the Counterregulatory Response to Hypoglycemia Following Antecedent Hypoglycemia. Diabetes 2022; 71:1063-1072. [PMID: 35179550 DOI: 10.2337/db21-0859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 02/15/2022] [Indexed: 11/13/2022]
Abstract
Antecedent hypoglycemia suppresses the counterregulatory responses to subsequent hypoglycemic episodes, which can be prevented by normalizing portal-mesenteric vein (PMV) glycemia alone during the antecedent bout. Since the sodium-glucose transporter 3 receptor has been implicated in PMV glucosensing, we hypothesized that PMV infusion of the sodium-glucose cotransporter 3 receptor agonist N-hydroxyethyl-1-deoxynojirimycin (miglitol) would rescue the sympathoadrenal response to subsequent hypoglycemia. Rats underwent hyperinsulinemic-hypoglycemic clamps on 2 consecutive days without miglitol infusion (antecedent hypoglycemia without miglitol [HYPO]) or with miglitol infused upstream in the PMV, perfusing the glucosensors, or adjacent to the liver, bypassing PMV glucosensors, on day 1 or day 2. Control animals underwent day 1 euglycemic clamps, followed by hypoglycemic clamps on day 2. Peak epinephrine (EPI) responses for HYPO on day 2 were significantly blunted when compared with controls. Miglitol infusion on day 1 proved ineffective in restoring the EPI response following antecedent hypoglycemia, but day 2 miglitol infusion restored EPI responses to control levels. As norepinephrine and glucagon demonstrated similar responses, day 2 administration of miglitol effectively restored the counterregulatory response following antecedent hypoglycemia. In subsequent experiments, we demonstrate similar results with reduced miglitol infusion doses, approaching those currently prescribed for type 2 diabetes (correcting for rodent size), as well as the efficacy of oral miglitol administration in restoring the counterregulatory responses following antecedent hypoglycemia.
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Affiliation(s)
- Anne J Jokiaho
- Department of Biological Sciences, University of Southern California, Los Angeles, CA
| | - Matthew Winchester
- Department of Biological Sciences, University of Southern California, Los Angeles, CA
| | - Casey M Donovan
- Department of Biological Sciences, University of Southern California, Los Angeles, CA
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Acetyl-CoA-carboxylase 1 (ACC1) plays a critical role in glucagon secretion. Commun Biol 2022; 5:238. [PMID: 35304577 PMCID: PMC8933412 DOI: 10.1038/s42003-022-03170-w] [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] [Received: 09/03/2020] [Accepted: 02/08/2022] [Indexed: 11/09/2022] Open
Abstract
Dysregulated glucagon secretion from pancreatic alpha-cells is a key feature of type-1 and type-2 diabetes (T1D and T2D), yet our mechanistic understanding of alpha-cell function is underdeveloped relative to insulin-secreting beta-cells. Here we show that the enzyme acetyl-CoA-carboxylase 1 (ACC1), which couples glucose metabolism to lipogenesis, plays a key role in the regulation of glucagon secretion. Pharmacological inhibition of ACC1 in mouse islets or αTC9 cells impaired glucagon secretion at low glucose (1 mmol/l). Likewise, deletion of ACC1 in alpha-cells in mice reduced glucagon secretion at low glucose in isolated islets, and in response to fasting or insulin-induced hypoglycaemia in vivo. Electrophysiological recordings identified impaired KATP channel activity and P/Q- and L-type calcium currents in alpha-cells lacking ACC1, explaining the loss of glucose-sensing. ACC-dependent alterations in S-acylation of the KATP channel subunit, Kir6.2, were identified by acyl-biotin exchange assays. Histological analysis identified that loss of ACC1 caused a reduction in alpha-cell area of the pancreas, glucagon content and individual alpha-cell size, further impairing secretory capacity. Loss of ACC1 also reduced the release of glucagon-like peptide 1 (GLP-1) in primary gastrointestinal crypts. Together, these data reveal a role for the ACC1-coupled pathway in proglucagon-expressing nutrient-responsive endocrine cell function and systemic glucose homeostasis.
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The Case for Clinical Trials with Novel GABAergic Drugs in Diabetes Mellitus and Obesity. Life (Basel) 2022; 12:life12020322. [PMID: 35207609 PMCID: PMC8876029 DOI: 10.3390/life12020322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/09/2022] [Accepted: 02/16/2022] [Indexed: 11/17/2022] Open
Abstract
Obesity and diabetes mellitus have become the surprising menaces of relative economic well-being worldwide. Gamma amino butyric acid (GABA) has a prominent role in the control of blood glucose, energy homeostasis as well as food intake at several levels of regulation. The effects of GABA in the body are exerted through ionotropic GABAA and metabotropic GABAB receptors. This treatise will focus on the pharmacologic targeting of GABAA receptors to reap beneficial therapeutic effects in diabetes mellitus and obesity. A new crop of drugs selectively targeting GABAA receptors has been under investigation for efficacy in stroke recovery and cognitive deficits associated with schizophrenia. Although these trials have produced mixed outcomes the compounds are safe to use in humans. Preclinical evidence is summarized here to support the rationale of testing some of these compounds in diabetic patients receiving insulin in order to achieve better control of blood glucose levels and to combat the decline of cognitive performance. Potential therapeutic benefits could be achieved (i) By resetting the hypoglycemic counter-regulatory response; (ii) Through trophic actions on pancreatic islets, (iii) By the mobilization of antioxidant defence mechanisms in the brain. Furthermore, preclinical proof-of-concept work, as well as clinical trials that apply the novel GABAA compounds in eating disorders, e.g., olanzapine-induced weight-gain, also appear warranted.
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Matus A, Trout KK, Sawyer AM, Riegel B. Sleep and hypoglycaemia symptom perception in adults with type-1 diabetes mellitus: A mixed-methods review. J Adv Nurs 2021; 78:14-25. [PMID: 34212428 DOI: 10.1111/jan.14947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/19/2021] [Accepted: 06/15/2021] [Indexed: 11/30/2022]
Abstract
AIMS The study aims to review, synthesize and integrate primary research on the relationship between sleep and hypoglycaemia symptom perception in adults with type-1 diabetes. DESIGN This mixed-methods review follows a convergent segregated approach to synthesis and integration of qualitative and quantitative evidence. DATA SOURCES With assistance of a biomedical librarian, a search of four databases was conducted (PubMed, CINAHL, Embase and PsycINFO) in June 2020. The review included primary research measuring sleep and hypoglycaemia symptom perception in adults (age ≥ 18 years) with type-1 diabetes in English. Studies that exclusively addressed children, type-2 diabetes or outcomes unrelated to sleep and hypoglycaemia symptom perception were excluded. REVIEW METHODS Screening focused on title and abstract review (n = 624). Studies not excluded after screening (n = 35) underwent full-text review. References of each study selected for inclusion (n = 6) were hand searched with one study added. All studies included in the review (n = 7) were critically appraised with JBI Critical Appraisal tools, and then data were extracted with systematic evaluation. RESULTS Quantitative synthesis found sleep reduces the magnitude of detectable symptoms and one's capacity to detect them. Qualitative synthesis found that individuals with type-1 diabetes perceive unpredictable severity, frequency and awareness of symptoms while asleep as an oppressive, lingering threat. Integration of findings highlights the troublesome duality of sleep's relationship with hypoglycaemia symptom perception. CONCLUSIONS Sleep presents a challenging time for individuals with type-1 diabetes. Further research examining the relationship between sleep and hypoglycaemia symptom perception is recommended as the number of studies limits this review. IMPACT Symptom perception is the main physiologic defense against severe hypoglycaemia in type-1 diabetes. This review found that sleep's relationship with hypoglycaemia symptoms has unique physiological and psychological components to address when providing comprehensive care. This review may inform future lines of inquiry that develop into interventions, improvements in practice and risk reduction for hypoglycaemia-related complications.
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Affiliation(s)
- Austin Matus
- School of Nursing, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly K Trout
- School of Nursing, University of Pennsylvania, Philadelphia, PA, USA
| | - Amy M Sawyer
- School of Nursing, University of Pennsylvania, Philadelphia, PA, USA
| | - Barbara Riegel
- School of Nursing, University of Pennsylvania, Philadelphia, PA, USA.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia.,International Center for Self-Care Research, Australian Catholic University, Melbourne, Victoria, Australia
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Li CY, Kuo CL, Chang YH, Lu CL, Martini S, Hou WH. Association between trajectory of severe hypoglycemia and dementia in patients with type 2 diabetes: A population-based study. J Epidemiol 2021; 32:423-430. [PMID: 33678721 PMCID: PMC9359896 DOI: 10.2188/jea.je20200518] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background We aimed to investigate associations between exposure to various trajectories of severe hypoglycemic events and risk of dementia in patients with type 2 diabetes. Methods In 2002–2003, 677,618 patients in Taiwan were newly diagnosed as having type 2 diabetes. Among them, 35,720 (5.3%) experienced severe hypoglycemic events during the 3-year baseline period following diagnosis. All patients were followed from the first day after baseline period to the date of dementia diagnosis, death, or the end of 2011. A group-based trajectory model was used to classify individuals with severe hypoglycemic events during the baseline period. Cox proportional hazard models with the competing risk method were used to relate dementia risk to various severe hypoglycemia trajectories. Results After a median follow-up 6.70 and 6.10 years for patients with and without severe hypoglycemia at baseline, respectively, 1,952 (5.5%) individuals with severe hypoglycemia and 23,492 (3.7%) without developed dementia during follow-up, for incidence rates of 109.80 and 61.88 per 10,000 person-years, respectively. Four groups of severe hypoglycemia trajectory were identified with a proportion of 18.06%, 33.19%, 43.25%, and 5.50%, respectively, for Groups 1 to 4. Groups 3 (early manifestation but with later decrease) and 4 (early and sustained manifestation) were associated with a significantly increased risk of dementia diagnosis, with a covariate-adjusted subdistribution hazard ratio of 1.22 (95% confidence interval, 1.14–1.31) and 1.25 (95% confidence interval, 1.02–1.54), respectively. Conclusion Our analysis highlighted that early manifestation of severe hypoglycemic events may contribute more than does late manifestation to the risk of dementia among individuals newly diagnosed as having type 2 diabetes.
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Affiliation(s)
- Chung-Yi Li
- Department of Public Health, College of Medicine, National Cheng Kung University.,Department of Epidemiology, Faculty of Public Health, Universitas Airlangga.,Department of Public Health, College of Public Health, China Medical University.,Department of Healthcare Administration, College of Medical and Health Science, Asia University
| | - Chia-Lun Kuo
- Department of Public Health, College of Medicine, National Cheng Kung University.,Department of Psychiatry, Tsaotun Psychiatric Center, Ministry of Health and Welfare
| | - Ya-Hui Chang
- Department of Public Health, College of Medicine, National Cheng Kung University
| | - Chin-Li Lu
- Graduate Institute of Food Safety, College of Agriculture and Natural Resources, National Chung Hsing University
| | - Santi Martini
- Department of Epidemiology, Faculty of Public Health, Universitas Airlangga
| | - Wen-Hsuan Hou
- School of Gerontology Health Management & Master Program in Long-Term Care, College of Nursing, Taipei Medical University.,Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University.,Center of Evidence-Based Medicine, Department of Education, Taipei Medical University Hospital
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Murthy TA, Grivell J, Hatzinikolas S, Chapple LAS, Chapman MJ, Stevens JE, Malbert CH, Rayner CK, Horowitz M, Jones KL, Marathe CS. Acceleration of Gastric Emptying by Insulin-Induced Hypoglycemia is Dependent on the Degree of Hypoglycemia. J Clin Endocrinol Metab 2021; 106:364-371. [PMID: 33230553 DOI: 10.1210/clinem/dgaa854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Indexed: 02/07/2023]
Abstract
CONTEXT Hypoglycemia is a major barrier to optimal glycemic control in insulin-treated diabetes. Recent guidelines from the American Diabetes Association have subcategorized "non-severe" hypoglycemia into level 1 (<3.9 mmol/L) and 2 (<3 mmol/L) hypoglycemia. Gastric emptying of carbohydrate is a major determinant of postprandial glycemia but its role in hypoglycemia counter-regulation remains underappreciated. "Marked" hypoglycemia (~2.6 mmol/L) accelerates gastric emptying and increases carbohydrate absorption in health and type 1 diabetes, but the impact of "mild" hypoglycemia (3.0-3.9 mmol/L) is unknown. OBJECTIVE To determine the effects of 2 levels of hypoglycemia, 2.6 mmol/L ("marked") and 3.6 mmol/L ("mild"), on gastric emptying in health. DESIGN, SETTING, AND SUBJECTS Fourteen healthy male participants (mean age: 32.9 ± 8.3 years; body mass index: 24.5 ± 3.4 kg/m2) from the general community underwent measurement of gastric emptying of a radiolabeled solid meal (100 g beef) by scintigraphy over 120 minutes on 3 separate occasions, while blood glucose was maintained at either ~2.6 mmol/L, ~3.6 mmol/L, or ~6 mmol/L in random order from 15 minutes before until 60 minutes after meal ingestion using glucose-insulin clamp. Blood glucose was then maintained at 6 mmol/L from 60 to 120 minutes on all days. RESULTS Gastric emptying was accelerated during both mild (P = 0.011) and marked (P = 0.001) hypoglycemia when compared to euglycemia, and was more rapid during marked compared with mild hypoglycemia (P = 0.008). Hypoglycemia-induced gastric emptying acceleration during mild (r = 0.57, P = 0.030) and marked (r = 0.76, P = 0.0014) hypoglycemia was related to gastric emptying during euglycemia. CONCLUSION In health, acceleration of gastric emptying by insulin-induced hypoglycemia is dependent on the degree of hypoglycemia and baseline rate of emptying.
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Affiliation(s)
- Tejaswini Arunachala Murthy
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia
| | | | - Seva Hatzinikolas
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
| | - Lee-Anne S Chapple
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Marianne J Chapman
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Intensive Care Unit, Royal Adelaide Hospital, Adelaide, Australia
| | | | | | - Christopher K Rayner
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, Australia
| | - Michael Horowitz
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Karen L Jones
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Chinmay S Marathe
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
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Joosten L, Boss M, Jansen T, Brom M, Buitinga M, Aarntzen E, Eriksson O, Johansson L, de Galan B, Gotthardt M. Molecular Imaging of Diabetes. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00041-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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George PS, McCrimmon RJ. Saxagliptin co-therapy in C-peptide negative Type 1 diabetes does not improve counter-regulatory responses to hypoglycaemia. Diabet Med 2016; 33:1283-90. [PMID: 26642301 DOI: 10.1111/dme.13046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/26/2015] [Indexed: 01/14/2023]
Abstract
AIMS To test the hypothesis that dipeptidyl peptidase-4 inhibition in C-peptide negative Type 1 diabetes would reduce glucose variability and exposure to hypoglycaemia and therefore may indirectly enhance counter-regulatory responses to subsequent hypoglycaemia. METHODS We conducted a 12-week double-blind, randomized, placebo-controlled crossover study. The study was conducted in a tertiary hospital outpatient clinic, with additional studies performed in a clinical research centre. After obtaining informed consent, we recruited 14 subjects with moderately well controlled Type 1 diabetes (HbA1c 64 ± 2 mmol/mol) of long duration (20.5 ± 2.7 years). The subjects received 12 weeks' therapy with oral saxagliptin (5 mg) or placebo. Glucose variability, assessed via continuous glucose monitoring, together with frequency of hypoglycaemia, hypoglycaemia awareness and symptomatic, cognitive and counter-regulatory hormone responses to experimental hypoglycaemia, were assessed. Additional outcome measures included HbA1c level, weight, total daily insulin dose and adverse events. RESULTS Saxagliptin co-therapy did not reduce glucose variability (low blood glucose index, average daily risk range), hypoglycaemia frequency or awareness and did not improve counter-regulatory hormonal responses during experimental hypoglycaemia (area under the curve for adrenaline 25 775 vs. 24 454, for placebo vs saxagliptin, respectively; P = 0.76). CONCLUSIONS No additional benefit of dipeptidyl peptidase-4 inhibition co-therapy with saxagliptin in the management of Type 1 diabetes was observed.
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Affiliation(s)
- P S George
- Cardiovascular and Diabetes Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - R J McCrimmon
- Cardiovascular and Diabetes Medicine, School of Medicine, University of Dundee, Dundee, UK
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De Backer I, Hussain SS, Bloom SR, Gardiner JV. Insights into the role of neuronal glucokinase. Am J Physiol Endocrinol Metab 2016; 311:E42-55. [PMID: 27189932 PMCID: PMC4967152 DOI: 10.1152/ajpendo.00034.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/13/2016] [Indexed: 12/17/2022]
Abstract
Glucokinase is a key component of the neuronal glucose-sensing mechanism and is expressed in brain regions that control a range of homeostatic processes. In this review, we detail recently identified roles for neuronal glucokinase in glucose homeostasis and counterregulatory responses to hypoglycemia and in regulating appetite. We describe clinical implications from these advances in our knowledge, especially for developing novel treatments for diabetes and obesity. Further research required to extend our knowledge and help our efforts to tackle the diabetes and obesity epidemics is suggested.
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Affiliation(s)
- Ivan De Backer
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, United Kingdom
| | - Sufyan S Hussain
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, United Kingdom
| | - Stephen R Bloom
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, United Kingdom
| | - James V Gardiner
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, United Kingdom
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14
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Sheen YJ, Sheu WHH. Association between hypoglycemia and dementia in patients with type 2 diabetes. Diabetes Res Clin Pract 2016; 116:279-87. [PMID: 27321346 DOI: 10.1016/j.diabres.2016.04.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 03/17/2016] [Accepted: 04/14/2016] [Indexed: 12/27/2022]
Abstract
In addition to increased risks of macrovascular and microvascular complications, patients with type 2 diabetes mellitus (T2DM) usually also are at increased risk for cognitive impairment and dementia. Hypoglycemia, a common consequence of diabetes treatment, is considered an independent risk factor for dementia in patients with T2DM. Hypoglycemia and dementia are clinically underestimated and are related to poor outcomes; thus, they may compromise the life expectancy of patients with T2DM. Epidemiological evidence of hypoglycemia-associated cognitive decline and dementia is highly varied. Acute, severe hypoglycemic episodes induce chronic subclinical brain damage, cognitive decline, and subsequent dementia. However, the effects of recurrent moderate hypoglycemia on cognitive decline and dementia remain largely uninvestigated. Poor glycemic control (including fluctuation of hemoglobin A1C [HbA1c] and glucose values) and the viscous circle of bidirectional associations between dementia and hypoglycemia may be clinically relevant. The possible pathophysiological hypotheses include post-hypoglycemic neuronal damage, inflammatory processes, coagulation defects, endothelial abnormalities, and synaptic dysfunction of hippocampal neurons during hypoglycemia episodes. This article reviews previous findings, provides insight into the detection of groups at high risk of hypoglycemia-associated dementia, and proposes specific strategies to minimize the potential burdens associated with hypoglycemia-related neurocognitive disorders in patients with T2DM.
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Affiliation(s)
- Yi-Jing Sheen
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Hospital, Ministry of Health and Welfare, No. 199 Section 1, Sanmin Road, Taichung 403, Taiwan
| | - Wayne H H Sheu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, No. 1650, Section 4, Taiwan Boulevard, Taichung 407, Taiwan; School of Medicine, National Defense Medical Center, Taipei, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan; Institute of Medical Technology, National Chung-Hsing University, Taichung, Taiwan.
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15
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Verberne AJM, Korim WS, Sabetghadam A, Llewellyn-Smith IJ. Adrenaline: insights into its metabolic roles in hypoglycaemia and diabetes. Br J Pharmacol 2016; 173:1425-37. [PMID: 26896587 DOI: 10.1111/bph.13458] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 01/20/2016] [Accepted: 02/11/2016] [Indexed: 01/05/2023] Open
Abstract
Adrenaline is a hormone that has profound actions on the cardiovascular system and is also a mediator of the fight-or-flight response. Adrenaline is now increasingly recognized as an important metabolic hormone that helps mobilize energy stores in the form of glucose and free fatty acids in preparation for physical activity or for recovery from hypoglycaemia. Recovery from hypoglycaemia is termed counter-regulation and involves the suppression of endogenous insulin secretion, activation of glucagon secretion from pancreatic α-cells and activation of adrenaline secretion. Secretion of adrenaline is controlled by presympathetic neurons in the rostroventrolateral medulla, which are, in turn, under the control of central and/or peripheral glucose-sensing neurons. Adrenaline is particularly important for counter-regulation in individuals with type 1 (insulin-dependent) diabetes because these patients do not produce endogenous insulin and also lose their ability to secrete glucagon soon after diagnosis. Type 1 diabetic patients are therefore critically dependent on adrenaline for restoration of normoglycaemia and attenuation or loss of this response in the hypoglycaemia unawareness condition can have serious, sometimes fatal, consequences. Understanding the neural control of hypoglycaemia-induced adrenaline secretion is likely to identify new therapeutic targets for treating this potentially life-threatening condition.
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Affiliation(s)
- A J M Verberne
- Clinical Pharmacology and Therapeutics Unit, Department of Medicine, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
| | - W S Korim
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - A Sabetghadam
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - I J Llewellyn-Smith
- Cardiovascular Medicine and Human Physiology, Flinders University, Bedford Park, SA, Australia
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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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Fang XL, Zhu XT, Chen SF, Zhang ZQ, Zeng QJ, Deng L, Peng JL, Yu JJ, Wang LN, Wang SB, Gao P, Jiang QY, Shu G. Differential gene expression pattern in hypothalamus of chickens during fasting-induced metabolic reprogramming: Functions of glucose and lipid metabolism in the feed intake of chickens. Poult Sci 2014; 93:2841-54. [DOI: 10.3382/ps.2014-04047] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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18
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Arbeláez AM, Su Y, Thomas JB, Hauch AC, Hershey T, Ances BM. Comparison of regional cerebral blood flow responses to hypoglycemia using pulsed arterial spin labeling and positron emission tomography. PLoS One 2013; 8:e60085. [PMID: 23555895 PMCID: PMC3610825 DOI: 10.1371/journal.pone.0060085] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 02/22/2013] [Indexed: 12/30/2022] Open
Abstract
Different brain regions sense and modulate the counterregulatory responses that can occur in response to declining plasma glucose levels. The aim of this study was to determine if changes in regional cerebral blood flow (rCBF) during hypoglycemia relative to euglycemia are similar for two imaging modalities–pulsed arterial spin labeling magnetic resonance imaging (PASL-MRI) and positron emission tomography (PET). Nine healthy non-diabetic participants underwent a hyperinsulinemic euglycemic (92±3 mg/dL) – hypoglycemic (53±1 mg/dL) clamp. Counterregulatory hormone levels were collected at each of these glycemic levels and rCBF measurements within the previously described network of hypoglycemia-responsive regions (thalamus, medial prefrontal cortex and globus pallidum) were obtained using PASL-MRI and [15O] water PET. In response to hypoglycemia, rCBF was significantly increased in the thalamus, medial prefrontal cortex, and globus pallidum compared to euglycemia for both PASL-MRI and PET methodologies. Both imaging techniques found similar increases in rCBF in the thalamus, medial prefrontal cortex, and globus pallidum in response to hypoglycemia. These brain regions may be involved in the physiologic and symptom responses to hypoglycemia. Compared to PET, PASL-MRI may provide a less invasive, less expensive method for assessing changes in rCBF during hypoglycemia without radiation exposure.
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Affiliation(s)
- Ana Maria Arbeláez
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
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Bonnet MS, Djelloul M, Tillement V, Tardivel C, Mounien L, Trouslard J, Troadec JD, Dallaporta M. Central NUCB2/Nesfatin-1-expressing neurones belong to the hypothalamic-brainstem circuitry activated by hypoglycaemia. J Neuroendocrinol 2013; 25:1-13. [PMID: 22958274 DOI: 10.1111/j.1365-2826.2012.02375.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 07/30/2012] [Accepted: 08/13/2012] [Indexed: 11/28/2022]
Abstract
Nesfatin-1 is a recently identified 82 amino acid peptide shown to have an anorexigenic effect on rodents when administrered centrally and peripherally. Nesfatin-1 is expressed not only in neurones of various brain areas, including the hypothalamic and brainstem nuclei, but also in peripheral organs, such as the stomach and the pancreas. Nesfatinergic neurones were reported to participate in the regulation of satiety signals and in the responses to other stimuli, including restraint stress, abdominal surgery, and lipopolysaccharide-induced inflammation. The present study aimed to investigate whether NUCB2/nesfatin-1 expressing neurones also take part in the central signalling activated in response to hypoglycaemia and therefore are involved in central glucose sensing. Using immunolabelling methods based on the detection of the neuronal activation marker c-Fos and of nesfatin-1, we showed that peripheral injection of insulin induced a strong activation of nesfatin-1-expressing neurones in the brain vagal-regulatory nuclei, including the arcuate nucleus, paraventricular nucleus, lateral hypothalamic area, dorsal motor nucleus of the vagus (DMNX) and nucleus of the tractus solitarius. In response to intracellular glucopaenia induced by i.p. or i.c.v. 2-deoxyglucose injection, the c-Fos/nesfatin-1 colocalisations observed at the hypothalamic and brainstem levels were similar to those observed after insulin-induced hypoglycaemia. Moreover, using Fluorogold as a retrograde tracer, we showed that nesfatinergic preganglionic DMNX neurones activated by hypoglycaemia target the stomach and the pancreas. Taken together, these results suggest that a subpopulation of nesfatinergic neurones belongs to the central network activated by hypoglycaemia, and that nesfatin-1 participates in the triggering of physiological and hormonal counter-regulations observed in response to hypoglycaemia.
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Affiliation(s)
- M S Bonnet
- Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, Aix-Marseille Université, Marseille, France
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Kliethermes CL, Heberlein U. Insulin attenuates the acquisition and expression of ethanol-induced locomotor sensitization in DBA/2J mice. Life Sci 2011; 89:968-74. [PMID: 22056372 DOI: 10.1016/j.lfs.2011.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 09/06/2011] [Accepted: 10/13/2011] [Indexed: 10/15/2022]
Abstract
AIM Ethanol-induced locomotor sensitization is a behavioral manifestation of physiological responses to repeated ethanol exposures. While ethanol exerts direct effects on multiple neurotransmitter systems in the brain, ethanol-induced changes in metabolic state, including acute hyperglycemia and inhibition of insulin signaling, also have plausible roles in the expression of ethanol-related behaviors through direct and indirect effects on brain function. The current experiments examined whether insulin administration or the resultant hypoglycemia might attenuate the development of sensitization to the locomotor stimulant effect of ethanol. MAIN METHODS Male and female DBA/2J mice received daily injections of 5 or 10 IU/kg insulin before or after a stimulating dose of ethanol and subsequent testing in an automated activity monitor. Blood glucose levels were determined upon the completion of the experiments. KEY FINDINGS Insulin injected prior to ethanol blunted the acute stimulant response as well as the acquisition and expression of locomotor sensitization, while insulin given after ethanol did not affect the development of the sensitized response. In a separate experiment, mice given glucose concurrently with insulin developed ethanol-induced locomotor sensitization normally. SIGNIFICANCE These experiments suggest that insulin attenuates the development of ethanol-induced locomotor sensitization, and that blood glucose levels can largely account for this effect. Further studies of the role of ethanol-induced metabolic states should provide novel information on the expression of ethanol-related behaviors.
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Seizure in a diabetic patient. Hypoglycemia or a side effect of continuous glucose monitoring? ACTA ACUST UNITED AC 2011; 59:144-6. [PMID: 22055803 DOI: 10.1016/j.endonu.2011.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 06/14/2011] [Accepted: 06/20/2011] [Indexed: 11/21/2022]
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Scheen AJ. Central nervous system: a conductor orchestrating metabolic regulations harmed by both hyperglycaemia and hypoglycaemia. DIABETES & METABOLISM 2011; 36 Suppl 3:S31-8. [PMID: 21211733 DOI: 10.1016/s1262-3636(10)70464-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent evidence suggests that the brain has a key role in the control of energy metabolism, body fat content and glucose metabolism. Neuronal systems, which regulate energy intake, energy expenditure, and endogenous glucose production, sense and respond to input from hormonal and nutrient-related signals that convey information regarding both body energy stores and current energy availability. In response to this input, adaptive changes occur that promote energy homeostasis and the maintenance of blood glucose levels in the normal range. Defects in this control system are implicated in the link between obesity and type 2 diabetes mellitus. The central nervous system may be considered the conductor of an orchestra involving many peripheral organs involved in these homeostatic processes. However, the brain is mainly a glucose-dependent organ, which can be damaged by both hypoglycaemia and hyperglycaemia. Hypoglycaemia unawareness is a major problem in clinical practice and is associated with an increased risk of coma. Stroke is another acute complication associated with diabetes mellitus, especially in elderly people, and the control of glucose level in this emergency situation remains challenging. The prognosis of stroke is worse in diabetic patients and both its prevention and management in at-risk patients should be improved. Finally, chronic diabetic encephalopathies, which may lead to cognitive dysfunction and even dementia, are also recognized. They may result from recurrent hypoglycaemia and/or from chronic hyperglycaemia leading to cerebral vascular damage. Functional imaging is of interest for exploring diabetes-associated cerebral abnormalities. Thus, the intimate relationship between the brain and diabetes is increasingly acknowledged in both research and clinical practice.
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Affiliation(s)
- A J Scheen
- Division of Diabetes, Nutrition and Metabolic Disorders, Department of Medicine, CHU Sart Tilman, University of Liège, Liège, Belgium.
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Halmos T, Suba I. The role of the brain in the regulation of metabolism and energy expenditure: the central role of insulin, the insulin resistance of the brain. Orv Hetil 2011; 152:83-91. [DOI: 10.1556/oh.2011.28981] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Regulatory role of the brain in energy expenditure, appetite, glucose metabolism, and central effects of insulin has been prominently studied. Certain neurons in the hypothalamus increase or decrease appetite via orexigenes and anorexigenes, regulating energy balance and food intake. Hypothalamus is the site of afferent and efferent stimuli between special nuclei and beta- and alpha cells, and it regulates induction/inhibition of glucose output from the liver. Incretines, produced in intestine and in certain brain cells (brain-gut hormones), link to special receptors in the hypothalamus. Central role of insulin has been proved both in animals and in humans. Insulin gets across the blood-brain barrier, links to special hypothalamic receptors, regulating peripheral glucose metabolism. Central glucose sensing, via “glucose-excited” and “glucose-inhibited” cells have outstanding role. Former are active in hyperglycaemia, latter in hypoglycaemia, via influencing beta– and alpha cells, independently of traditional metabolic pathways. Evidence of brain insulin resistance needs centrally acting drugs, paradigm changes in therapy and prevention of metabolic syndrome, diabetes, cardiovascular and oncological diseases. Orv. Hetil., 2011, 152, 83–91.
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Affiliation(s)
- Tamás Halmos
- MAZSIHISZ Szeretet Kórház Metabolikus Ambulancia Budapest Amerikai út 53–55. 1145
| | - Ilona Suba
- Bajcsy-Zsilinszky Kórház-Rendelőintézet Tüdőgondozó Budapest
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Abstract
The counterregulatory response to hypoglycemia is a complex and well-coordinated process. As blood glucose concentration declines, peripheral and central glucose sensors relay this information to central integrative centers to coordinate neuroendocrine, autonomic, and behavioral responses and avert the progression of hypoglycemia. Diabetes, both type 1 and type 2, can perturb these counterregulatory responses. Moreover, defective counterregulation in the setting of diabetes can progress to hypoglycemia unawareness. While the mechanisms that underlie the development of hypoglycemia unawareness are not completely known, possible causes include altered sensing of hypoglycemia by the brain and/or impaired coordination of responses to hypoglycemia. Further study is needed to better understand the intricacies of the counterregulatory response and the mechanisms contributing to the development of hypoglycemia unawareness.
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Affiliation(s)
- Nolawit Tesfaye
- Department of Medicine, Division of Endocrinology and Diabetes, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN 55455, USA
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Graveling A, Frier B. Impaired awareness of hypoglycaemia: a review. DIABETES & METABOLISM 2010; 36 Suppl 3:S64-74. [DOI: 10.1016/s1262-3636(10)70470-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Zhou L, Podolsky N, Sang Z, Ding Y, Fan X, Tong Q, Levin BE, McCrimmon RJ. The medial amygdalar nucleus: a novel glucose-sensing region that modulates the counterregulatory response to hypoglycemia. Diabetes 2010; 59:2646-52. [PMID: 20627933 PMCID: PMC3279559 DOI: 10.2337/db09-0995] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE To determine whether the medial amygdalar nucleus (MAN) represents a novel brain glucose-sensing region involved in the detection of hypoglycemia and generation of a counterregulatory hormone response. RESEARCH DESIGN AND METHODS Fura-2 calcium imaging was used to assess glucose responsivity in neurons isolated from the MAN and single-cell real-time reverse transcription PCR used to examine gene expression within glucose-responsive neurons. In vivo studies with local MAN perfusion of the glucoprivic agent, 2-deoxyglucose (2-DG), under normal and hypoglycemic conditions and also after MAN lesioning with ibotenic acid, were used to examine the functional role of MAN glucose sensors. In addition, retrograde neuronal tracer studies were used to examine reciprocal pathways between the MAN and the ventromedial hypothalamus (VMH). RESULTS The MAN contains a population of glucose-sensing neurons (13.5%), which express glucokinase, and the selective urocortin 3 (UCN3) receptor CRH-R2, but not UCN3 itself. Lesioning the MAN suppressed, whereas 2-DG infusion amplified, the counterregulatory response to hyperinsulinemic hypoglycemia in vivo. However, 2-DG infusion to the MAN or VMH under normoglycemic conditions had no systemic effect. The VMH is innervated by UCN3 neurons that arise mainly from the MAN, and ∼1/3 of MAN UCN3 neurons are active during mild hypoglycemia. CONCLUSIONS The MAN represents a novel limbic glucose-sensing region that contains characteristic glucokinase-expressing glucose-sensing neurons that respond directly to manipulations of glucose availability both in vitro and in vivo. Moreover, UCN3 neurons may provide feedback inhibitory regulation of the counterregulatory response through actions within the VMH and the MAN.
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Affiliation(s)
- Ligang Zhou
- Department of Internal Medicine, Yale University, New Haven, Connecticut
| | - Nina Podolsky
- VA Medical Center, Neurology Service, East Orange, New Jersey
| | - Zhen Sang
- Department of Internal Medicine, Yale University, New Haven, Connecticut
| | - Yuyan Ding
- Department of Internal Medicine, Yale University, New Haven, Connecticut
| | - Xiaoning Fan
- Department of Internal Medicine, Yale University, New Haven, Connecticut
| | - Qingchun Tong
- Department of Internal Medicine, Beth Israel Deaconness Medical Center, Boston, Massachusetts
| | - Barry E. Levin
- VA Medical Center, Neurology Service, East Orange, New Jersey
| | - Rory J. McCrimmon
- Department of Internal Medicine, Yale University, New Haven, Connecticut
- Biomedical Research Institute, University of Dundee, Dundee, Scotland
- Corresponding author: Rory J. McCrimmon,
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Affiliation(s)
- Stephanie A. Amiel
- From the Department of Medicine, King's College London School of Medicine, London, England
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