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Snyder HM, Asthana S, Bain L, Brinton R, Craft S, Dubal DB, Espeland MA, Gatz M, Mielke MM, Raber J, Rapp PR, Yaffe K, Carrillo MC. Sex biology contributions to vulnerability to Alzheimer's disease: A think tank convened by the Women's Alzheimer's Research Initiative. Alzheimers Dement 2016; 12:1186-1196. [PMID: 27692800 DOI: 10.1016/j.jalz.2016.08.004] [Citation(s) in RCA: 156] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 01/29/2023]
Abstract
More than 5 million Americans are living with Alzheimer's disease (AD) today, and nearly two-thirds of Americans with AD are women. This sex difference may be due to the higher longevity women generally experience; however, increasing evidence suggests that longevity alone is not a sufficient explanation and there may be other factors at play. The Alzheimer's Association convened an expert think tank to focus on the state of the science and level of evidence around gender and biological sex differences for AD, including the knowledge gaps and areas of science that need to be more fully addressed. This article summarizes the think tank discussion, moving forward a research agenda and funding program to better understand the biological underpinnings of sex- and gender-related disparities of risk for AD.
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Affiliation(s)
- Heather M Snyder
- Division of Medical & Scientific Relations, Alzheimer's Association, Chicago, IL, USA.
| | - Sanjay Asthana
- Department of Medicine, University of Wisconsin School of Medicine, Madison, WI, USA
| | - Lisa Bain
- Independent Science Writer, Philadelphia, PA, USA
| | - Roberta Brinton
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA; Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA; Department of Neurology, University of Southern California, Los Angeles, CA, USA
| | - Suzanne Craft
- Department of Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Dena B Dubal
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Mark A Espeland
- Department of Biostatistical Science, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Margaret Gatz
- Department of Psychology, University of Southern California, Los Angeles, CA, USA
| | - Michelle M Mielke
- Division of Epidemiology, Department of Health Sciences Research and Neurology, Mayo Clinic, Rochester, MN, USA
| | - Jacob Raber
- Departments of Behavioral Neuroscience, Neurology, and Radiation Medicine, Oregon Health & Science University, Portland, OR, USA; Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR, USA
| | - Peter R Rapp
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging Intramural Research Program, Baltimore, MD, USA
| | - Kristine Yaffe
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA
| | - Maria C Carrillo
- Division of Medical & Scientific Relations, Alzheimer's Association, Chicago, IL, USA
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Lioutas VA, Alfaro-Martinez F, Bedoya F, Chung CC, Pimentel DA, Novak V. Intranasal Insulin and Insulin-Like Growth Factor 1 as Neuroprotectants in Acute Ischemic Stroke. Transl Stroke Res 2015; 6:264-75. [PMID: 26040423 DOI: 10.1007/s12975-015-0409-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 04/16/2015] [Accepted: 05/13/2015] [Indexed: 12/22/2022]
Abstract
Treatment options for stroke remain limited. Neuroprotective therapies, in particular, have invariably failed to yield the expected benefit in stroke patients, despite robust theoretical and mechanistic background and promising animal data. Insulin and insulin-like growth factor 1 (IGF-1) play a pivotal role in critical brain functions, such as energy homeostasis, neuronal growth, and differentiation. They may exhibit neuroprotective properties in acute ischemic stroke based upon their vasodilatory, anti-inflammatory and antithrombotic effects, as well as improvements of functional connectivity, neuronal metabolism, neurotransmitter regulation, and remyelination. Intranasally administered insulin has demonstrated a benefit for prevention of cognitive decline in older people, and IGF-1 has shown potential benefit to improve functional outcomes in animal models of acute ischemic stroke. The intranasal route presents a feasible, tolerable, safe, and particularly effective administration route, bypassing the blood-brain barrier and maximizing distribution to the central nervous system (CNS), without the disadvantages of systemic side effects and first-pass metabolism. This review summarizes the neuroprotective potential of intranasally administered insulin and IGF-1 in stroke patients. We present the theoretical background and pathophysiologic mechanisms, animal and human studies of intranasal insulin and IGF-1, and the safety and feasibility of intranasal route for medication administration to the CNS.
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Affiliation(s)
- Vasileios-Arsenios Lioutas
- Department of Neurology, Division of Cerebrovascular Diseases, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Palmer 127, Boston, MA, 02215, USA,
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Claxton A, Baker LD, Wilkinson CW, Trittschuh EH, Chapman D, Watson GS, Cholerton B, Plymate SR, Arbuckle M, Craft S. Sex and ApoE genotype differences in treatment response to two doses of intranasal insulin in adults with mild cognitive impairment or Alzheimer's disease. J Alzheimers Dis 2013; 35:789-97. [PMID: 23507773 DOI: 10.3233/jad-122308] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A previous clinical trial demonstrated that four months of treatment with intranasal insulin improves cognition and function for patients with Alzheimer's disease (AD) or mild cognitive impairment (MCI), but prior studies suggest that response to insulin treatment may differ by sex and ApoE ε4 carriage. Thus, responder analyses using repeated measures analysis of covariance were completed on the trial's 104 participants with MCI or AD who received either placebo or 20 or 40 IU of insulin for 4 months, administered by a nasal delivery device. Results indicate that men and women with memory impairment responded differently to intranasal insulin treatment. On delayed story memory, men and women showed cognitive improvement when taking 20 IU of intranasal insulin, but only men showed cognitive improvement for the 40 IU dose. The sex difference was most apparent for ApoE ε4 negative individuals. For the 40 IU dose, ApoE ε4 negative men improved while ApoE ε4 negative women worsened. Their ApoE ε4 positive counterparts remained cognitively stable. This sex effect was not detected in functional measures. However, functional abilities were relatively preserved for women on either dose of intranasal insulin compared with men. Unlike previous studies with young adults, neither men nor women taking intranasal insulin exhibited a significant change in weight over 4 months of treatment.
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Affiliation(s)
- Amy Claxton
- Geriatric Research, Education, & Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
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Kravitz E, Schmeidler J, Beeri MS. Type 2 diabetes and cognitive compromise: potential roles of diabetes-related therapies. Endocrinol Metab Clin North Am 2013; 42:489-501. [PMID: 24011882 PMCID: PMC3767929 DOI: 10.1016/j.ecl.2013.05.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Type 2 diabetes, like dementia, disproportionately affects the elderly. Diabetes has consistently been associated with risk of dementia, mild cognitive impairment, and cognitive decline suggesting that cognitive compromise is a deleterious manifestation of diabetes. This review summarizes observational studies and clinical trials of diabetes medications and their respective associations and effects on cognitive outcomes. Despite biological plausibility, results from most human clinical trials have failed to show any efficacy in treating Alzheimer disease symptomatology and pathology. Clinical trials targeting vascular-related outcomes, diabetic patients, or cognitively normal elderly at risk for dementia, may provide greater cognitive benefits.
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Affiliation(s)
- Efrat Kravitz
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Israel
| | - James Schmeidler
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY
| | - Michal Schnaider Beeri
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Israel
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY
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Begg DP, Woods SC. Interactions between the central nervous system and pancreatic islet secretions: a historical perspective. ADVANCES IN PHYSIOLOGY EDUCATION 2013; 37:53-60. [PMID: 23471249 PMCID: PMC3776474 DOI: 10.1152/advan.00167.2012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 01/14/2013] [Indexed: 05/10/2023]
Abstract
The endocrine pancreas is richly innervated with sympathetic and parasympathetic projections from the brain. In the mid-20th century, it was established that α-adrenergic activation inhibits, whereas cholinergic stimulation promotes, insulin secretion; this demonstrated the importance of the sympathetic and parasympathetic systems in pancreatic endocrine function. It was later established that insulin injected peripherally could act within the brain, leading to the discovery of insulin and insulin receptors within the brain and the receptor-mediated transport of insulin into the central nervous system from endothelial cells. The insulin receptor within the central nervous system is widely distributed, reflecting insulin's diverse range of actions, including acting as an adiposity signal to reduce food intake and increase energy expenditure, regulation of systemic glucose responses, altering sympathetic activity, and involvement in cognitive function. As observed with central insulin administration, the pancreatic hormones glucagon, somatostatin, pancreatic polypeptide, and amylin can each also reduce food intake. Pancreatic and also gut hormones are released cephalically, in what is an important mechanism to prepare the body for a meal and prevent excessive postprandial hyperglycemia.
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Affiliation(s)
- Denovan P Begg
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH 45237, USA
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