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Giannos P, Prokopidis K, Church DD, Kirk B, Morgan PT, Lochlainn MN, Macpherson H, Woods DR, Ispoglou T. Associations of Bioavailable Serum Testosterone With Cognitive Function in Older Men: Results From the National Health and Nutrition Examination Survey. J Gerontol A Biol Sci Med Sci 2023; 78:151-157. [PMID: 35927217 PMCID: PMC9879757 DOI: 10.1093/gerona/glac162] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Age-associated cognitive decline may be influenced by testosterone status. However, studies evaluating the impact of bioavailable testosterone, the active, free testosterone, on cognitive function are scarce. Our study determined the relationship between calculated bioavailable testosterone and cognitive performance in older men. METHODS We used data from the U.S. National Health and Nutrition Examination Survey (NHANES) between 2013 and 2014. This study consisted of 208 men aged ≥60 years. Bioavailable serum testosterone was calculated based on the total serum testosterone, sex hormone-binding globulin, and albumin levels, whereas cognitive performance was assessed through the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test (WLLT), Word List Recall Test (WLRT), and Intrusion Word Count Test (WLLT-IC and WLRT-IC), the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST). Multiple linear regression analyses were performed upon adjustment for age, ethnicity, socioeconomic status, education level, medical history, body mass index, energy, alcohol intake, physical activity levels, and sleep duration. RESULTS A significant positive association between bioavailable testosterone and DSST (β: 0.049, p = .002) score was detected, with no signs of a plateau effect. No significant associations with CERAD WLLT (p = .132), WLRT (p = .643), WLLT-IC (p = .979), and WLRT-IC (p = .387), and AFT (p = .057) were observed. CONCLUSION Calculated bioavailable testosterone presented a significant positive association with processing speed, sustained attention, and working memory in older men above 60 years of age. Further research is warranted to elucidate the impact of the inevitable age-related decline in testosterone on cognitive function in older men.
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Affiliation(s)
- Panagiotis Giannos
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London, UK.,Society of Meta-research and Biomedical Innovation, London, UK
| | - Konstantinos Prokopidis
- Society of Meta-research and Biomedical Innovation, London, UK.,Department of Musculoskeletal Biology, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - David D Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging and Longevity, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ben Kirk
- Department of Medicine-Western Health, Melbourne Medical School, University of Melbourne, Melbourne, Victoria, Australia.,Australian Institute for Musculoskeletal Science (AIMSS), University of Melbourne and Western Health, St. Albans, Melbourne, Victoria, Australia
| | - Paul T Morgan
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.,Department of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, UK
| | - Mary Ni Lochlainn
- Department of Twin Research and Genetic Epidemiology, King's College London, London, UK
| | - Helen Macpherson
- Deakin University, Geelong, Victoria, Australia.,Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Burwood, Victoria, Australia
| | - David R Woods
- Defence Medical Services, Lichfield, UK.,Carnegie School of Sport, Leeds Beckett University, Leeds, UK
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2
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Li Y, Li S, Xu S, Yu H, Tang L, Liu X, Wang X, Zhang Y, Zhang K, Mi S, Chen M, Cui H. Association of Androgens and Gonadotropins with Amnestic Mild Cognitive Impairment and Probable Alzheimer’s Disease in Chinese Elderly Men. J Alzheimers Dis 2020; 78:277-290. [DOI: 10.3233/jad-200233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Age-related hormone changes play important roles in cognitive decline in older men, and apolipoprotein E ɛ4 (APOE ɛ4) is a risk factor for Alzheimer’s disease (AD). Objective: This study aimed to investigate the interactive role of androgen decline and APOE ɛ4 genotype in the pathogenesis of amnestic mild cognitive impairment (aMCI) and AD. Methods: In total, 576 elderly men over 65 years old from communities in Shijiazhuang were enrolled in this study, including 243 with normal cognition (NC), 271 with aMCI, and 62 with probable AD. Cognitive function was evaluated with a battery of neuropsychological tests. The serum levels of androgen and gonadotropin were detected by ELISA and chemiluminescence immunoassay. Results: The levels of free testosterone (FT) and dihydrotestosterone (DHT) were lower in the aMCI group (p < 0.05), and even lower in the AD group (p < 0.001), but the levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) were higher in AD group (p < 0.01), comparing with that in NC or aMCI group. The interaction of lower FT or DHT levels with APOE ɛ4 had a risk role in global cognitive impairment (p < 0.05). The area under the curve (AUC) of the ROC curve for predicting aMCI by serum FT levels was 0.745. Conclusion: These results indicated that the interaction of androgen decline and APOE ɛ4 genotype play a role in aMCI and AD. Serum FT levels have a predictive value for aMCI and might be a potential biomarker for prodromal AD.
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Affiliation(s)
- Yan Li
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, P. R. China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, P. R. China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Shijiazhuang, P. R. China
- College of Nursing, Hebei Medical University, Shijiazhuang, P. R. China
| | - Sha Li
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, P. R. China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, P. R. China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Shijiazhuang, P. R. China
| | - Shunjiang Xu
- Central Laboratory, The First Hospital of Hebei Medical University, Shijiazhuang, P. R. China
| | - Hong Yu
- College of Nursing, Hebei Medical University, Shijiazhuang, P. R. China
| | - Longmei Tang
- Department of Epidemiology and Statistics, School of Public Health, Hebei Medical University, Shijiazhuang, P. R. China
| | - Xiaoyun Liu
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, P. R. China
- Department of Neurology, The Second Hospital of Hebei Medical University, Shijiazhuang, P. R. China
| | - Xuemei Wang
- College of Nursing, Hebei Medical University, Shijiazhuang, P. R. China
| | - Yuanyuan Zhang
- College of Nursing, Hebei Medical University, Shijiazhuang, P. R. China
| | - Kaixia Zhang
- Central Laboratory, The First Hospital of Hebei Medical University, Shijiazhuang, P. R. China
| | - Shixiong Mi
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, P. R. China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, P. R. China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Shijiazhuang, P. R. China
| | - Meiqin Chen
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, P. R. China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, P. R. China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Shijiazhuang, P. R. China
| | - Huixian Cui
- Department of Human Anatomy, Hebei Medical University, Shijiazhuang, P. R. China
- Neuroscience Research Center, Hebei Medical University, Shijiazhuang, P. R. China
- Hebei Key Laboratory of Neurodegenerative Disease Mechanism, Shijiazhuang, P. R. China
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3
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Associations between CLU polymorphisms and memory performance: The role of serum lipids in Alzheimer's disease. J Psychiatr Res 2020; 129:281-288. [PMID: 32882505 DOI: 10.1016/j.jpsychires.2020.07.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/10/2020] [Accepted: 07/15/2020] [Indexed: 11/22/2022]
Abstract
CLU encoding clusterin, has been reported to associate with Alzherimer's disease (AD) by genome-wide association studies (GWAS) based on Caucasian populations. Our previous case-control study has independently confirmed the disease association of CLU in Chinese population. Since little is known about the underlying mechanism of CLU in AD, we have conducted this study to investigate whether the genetic impact of CLU polymorphisms on cognitive functioning is via serum lipid's dysfunction. Three GWAS previously published CLU polymorphisms including rs2279590, rs11136000 and rs9331888, were genotyped in 689 subjects. Serum levels of triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured and tested as mediators. Delayed Word Recall Test (DWRT) was used to evaluate subjects' memory performance. Multiple mediation analysis, a nonparametric procedure to create confidence interval, was performed according to Preacher and Hayes's Bootstrapping method. Our findings suggested significant correlation between CLU polymorphism and DWRT scores for rs11136000 (p = 0.045) after adjustment for age, gender, body mass index, and APOEε4 status, with borderline significant correlation for rs2279590 (p = 0.058). Both T allele of rs11136000 and A allele of rs2279590 were negatively correlated with serum TG levels (p = 0.003; p = 0.001, separately). Moreover, A allele of rs2279590 was positively correlated with serum HDL-C levels (p = 0.015). Consistent with our hypotheses, the genetic impact of CLU polymorphisms on memory performance were partially mediated through TG (rs11136000 95% CI [-0.099,-0.003] and rs2279590 95% CI [-0.104, -0.004]), but not through HDL-C and LDL-C. Our findings indicate CLU polymorphisms may modify AD susceptibility through lipid metabolic pathway.
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4
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Kaufman MJ, Kanayama G, Hudson JI, Pope HG. Supraphysiologic-dose anabolic-androgenic steroid use: A risk factor for dementia? Neurosci Biobehav Rev 2019; 100:180-207. [PMID: 30817935 PMCID: PMC6451684 DOI: 10.1016/j.neubiorev.2019.02.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/13/2019] [Accepted: 02/17/2019] [Indexed: 02/06/2023]
Abstract
Supraphysiologic-dose anabolic-androgenic steroid (AAS) use is associated with physiologic, cognitive, and brain abnormalities similar to those found in people at risk for developing Alzheimer's Disease and its related dementias (AD/ADRD), which are associated with high brain β-amyloid (Aβ) and hyperphosphorylated tau (tau-P) protein levels. Supraphysiologic-dose AAS induces androgen abnormalities and excess oxidative stress, which have been linked to increased and decreased expression or activity of proteins that synthesize and eliminate, respectively, Aβ and tau-P. Aβ and tau-P accumulation may begin soon after initiating supraphysiologic-dose AAS use, which typically occurs in the early 20s, and their accumulation may be accelerated by other psychoactive substance use, which is common among non-medical AAS users. Accordingly, the widespread use of supraphysiologic-dose AAS may increase the numbers of people who develop dementia. Early diagnosis and correction of sex-steroid level abnormalities and excess oxidative stress could attenuate risk for developing AD/ADRD in supraphysiologic-dose AAS users, in people with other substance use disorders, and in people with low sex-steroid levels or excess oxidative stress associated with aging.
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Affiliation(s)
- Marc J Kaufman
- McLean Imaging Center, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA.
| | - Gen Kanayama
- Biological Psychiatry Laboratory, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - James I Hudson
- Biological Psychiatry Laboratory, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
| | - Harrison G Pope
- Biological Psychiatry Laboratory, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, Boston, MA 02115, USA
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5
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Song J, Jung C, Kim OY. The Novel Implication of Androgen in Diabetes-induced Alzheimer's Disease. J Lipid Atheroscler 2017. [DOI: 10.12997/jla.2017.6.2.66] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Juhyun Song
- Department of Anatomy, Chonnam National University Medical School, Gwangju, Korea
| | - Chaeyong Jung
- Department of Anatomy, Chonnam National University Medical School, Gwangju, Korea
| | - Oh Yoen Kim
- Department of Food Science and Nutrition, Dong-A University, Busan, Korea
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6
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Lin KA, Rundel C, Doraiswamy PM. Serum SHBG Levels are not Associated with Longitudinal Cognitive Decline in Mild Cognitive Impairment. J Alzheimers Dis 2016; 55:1123-1130. [DOI: 10.3233/jad-160513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Katherine Amy Lin
- Department of Psychiatry, Duke University Medical Center, Durham, NC, USA
- Duke Institute for Brain Sciences, Duke University, Durham, NC, USA
| | - Colin Rundel
- Department of Statistical Science, Duke University, Durham, NC, USA
| | - P. Murali Doraiswamy
- Department of Psychiatry, Duke University Medical Center, Durham, NC, USA
- Duke Institute for Brain Sciences, Duke University, Durham, NC, USA
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7
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The Potential of Gonadal Hormone Signalling Pathways as Therapeutics for Dementia. J Mol Neurosci 2016; 60:336-348. [PMID: 27525638 DOI: 10.1007/s12031-016-0813-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 08/01/2016] [Indexed: 12/17/2022]
Abstract
Dementia is an ever-expanding problem facing an ageing society. Currently, there is a sharp paucity of treatment strategies. It has long been known that sex hormones, namely 17β-estradiol and testosterone, possess neuroprotective- and cognitive-enhancing qualities. However, certain lacunae in the knowledge underlying their molecular mechanisms have delayed their use as treatment strategies in dementia. With recent advancements in pharmacology and molecular biology, especially in the development of safer selective oestrogen receptor modulators and the recent discovery of the small-molecule brain-derived neurotrophic factor receptor agonist, 7,8-dihydroxyflavone, the exploitation of these signalling pathways for clinical use has become possible. This review aims to adumbrate the evidence and hurdles underscoring the use of sex hormones in the treatment of dementia as well as discussing some direction that is required to advance the translation of evidence into practise.
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8
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Cherrier MM, Anderson K, Shofer J, Millard S, Matsumoto AM. Testosterone treatment of men with mild cognitive impairment and low testosterone levels. Am J Alzheimers Dis Other Demen 2015; 30:421-30. [PMID: 25392187 PMCID: PMC10852633 DOI: 10.1177/1533317514556874] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2024]
Abstract
INTRODUCTION This study investigated the effects of testosterone (T) treatment on cognition, mood, and quality of life in men with mild cognitive impairment (MCI) and low serum T levels. METHODS A total of 351 community-dwelling men were screened, and 37 men evidenced both MCI and low T of whom 27 agreed for further screening. Twenty-two met all the study inclusion/exclusion criteria and enrolled in a 6-month randomized, double-blind, placebo-controlled study. RESULTS Total T levels significantly increased in the T treatment group. No significant changes were observed in measures of cognition, mood, or quality of life other than improvement in 1 objective measure of verbal memory (P < .05) and decreased depression symptoms (P < .02) in the treatment group. CONCLUSIONS Testosterone treatment may modestly improve verbal memory and depression symptoms in men with both MCI and low T.
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Affiliation(s)
- M M Cherrier
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - K Anderson
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - J Shofer
- Geriatric, Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, USA
| | - S Millard
- Geriatric, Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, USA
| | - A M Matsumoto
- Geriatric, Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, USA Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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9
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Abstract
Alzheimer's disease (AD), the most common form of dementia, is a chronic, progressive neurodegenerative disease that manifests clinically as a slow global decline in cognitive function, including deterioration of memory, reasoning, abstraction, language and emotional stability, culminating in a patient with end-stage disease, totally dependent on custodial care. With a global ageing population, it is predicted that there will be a marked increase in the number of people diagnosed with AD in the coming decades, making this a significant challenge to socio-economic policy and aged care. Global estimates put a direct cost for treating and caring for people with dementia at $US604 billion, an estimate that is expected to increase markedly. According to recent global statistics, there are 35.6 million dementia sufferers, the number of which is predicted to double every 20 years, unless strategies are implemented to reduce this burden. Currently, there is no cure for AD; while current therapies may temporarily ameliorate symptoms, death usually occurs approximately 8 years after diagnosis. A greater understanding of AD pathophysiology is paramount, and attention is now being directed to the discovery of biomarkers that may not only facilitate pre-symptomatic diagnosis, but also provide an insight into aberrant biochemical pathways that may reveal potential therapeutic targets, including nutritional ones. AD pathogenesis develops over many years before clinical symptoms appear, providing the opportunity to develop therapy that could slow or stop disease progression well before any clinical manifestation develops.
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10
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Morley JE. New Horizons in the Management of Alzheimer Disease. J Am Med Dir Assoc 2015; 16:1-5. [DOI: 10.1016/j.jamda.2014.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 10/29/2014] [Indexed: 12/21/2022]
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11
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Ampadu J, Morley JE. Heart failure and cognitive dysfunction. Int J Cardiol 2015; 178:12-23. [DOI: 10.1016/j.ijcard.2014.10.087] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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12
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Samaras N, Papadopoulou MA, Samaras D, Ongaro F. Off-label use of hormones as an antiaging strategy: a review. Clin Interv Aging 2014; 9:1175-86. [PMID: 25092967 PMCID: PMC4116364 DOI: 10.2147/cia.s48918] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Given demographic evolution of the population in modern societies, one of the most important health care needs is successful aging with less frailty and dependency. During the last 20 years, a multitude of anti-aging practices have appeared worldwide, aiming at retarding or even stopping and reversing the effects of aging on the human body. One of the cornerstones of anti-aging is hormone replacement. At present, women live one third of their lives in a state of sex-hormone deficiency. Men are also subject to age-related testosterone decline, but andropause remains frequently under-diagnosed and under-treated. Due to the decline of hormone production from gonads in both sexes, the importance of dehydroepiandrosterone (DHEA) in steroid hormone production increases with age. However, DHEA levels also decrease with age. Also, growth hormone age-associated decrease may be so important that insulin growth factor-1 levels found in elderly individuals are sometimes as low as those encountered in adult patients with established deficiency. Skin aging as well as decreases in lean body mass, bone mineral density, sexual desire and erectile function, intellectual activity and mood have all been related to this decrease of hormone production with age. Great disparities exist between recommendations from scientific societies and actual use of hormone supplements in aging and elderly patients. In this article, we review actual data on the effects of age related hormone decline on the aging process and age-related diseases such as sarcopenia and falls, osteoporosis, cognitive decline, mood disorders, cardiovascular health and sexual activity. We also provide information on the efficiency and safety of hormone replacement protocols in aging patients. Finally, we argue on future perspectives of such protocols as part of everyday practice.
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Affiliation(s)
| | | | - Dimitrios Samaras
- Department of Medical Specialties, Clinical Nutrition, Geneva University Hospitals, Geneva, Switzerland
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13
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Morley JE. Mild Cognitive Impairment—A Treatable Condition. J Am Med Dir Assoc 2014; 15:1-5. [DOI: 10.1016/j.jamda.2013.11.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 11/04/2013] [Indexed: 01/24/2023]
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14
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Panizzon MS, Hauger R, Xian H, Vuoksimaa E, Spoon KM, Mendoza SP, Jacobson KC, Vasilopoulos T, Rana BK, McKenzie R, McCaffery JM, Lyons MJ, Kremen WS, Franz CE. Interaction of APOE genotype and testosterone on episodic memory in middle-aged men. Neurobiol Aging 2013; 35:1778.e1-8. [PMID: 24444806 DOI: 10.1016/j.neurobiolaging.2013.12.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 12/19/2013] [Accepted: 12/21/2013] [Indexed: 01/12/2023]
Abstract
Age-related changes in testosterone are believed to be a key component of the processes that contribute to cognitive aging in men. The APOE-ε4 allele may interact with testosterone and moderate the hormone's association with cognition. The goals of the present study were to examine the degree to which free testosterone is associated with episodic memory in a community-based sample of middle-aged men, and examine the potential interaction between free testosterone and the APOE-ε4 allele. Data were used from 717 participants in the Vietnam Era Twin Study of Aging. Average age was 55.4 years (standard deviation = 2.5). Significant positive associations were observed between free testosterone level and verbal episodic memory, as well as a significant interaction between free testosterone and APOE-ε4 status. In ε4 carriers free testosterone was positively associated with verbal episodic memory performance (story recall), whereas no association was observed in ε4 noncarriers. Results support the hypothesis that APOE-ε4 status increases susceptibility to other risk factors, such as low testosterone, which may ultimately contribute to cognitive decline or dementia.
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Affiliation(s)
- Matthew S Panizzon
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA.
| | - Richard Hauger
- Department of Psychiatry, University of California, San Diego, CA, USA; VA San Diego Healthcare System, CA, USA; Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, USA
| | - Hong Xian
- Department of Biostatistics, St. Louis University, College for Public Health & Social Justice, St. Louis, MO, USA; Research Service, St. Louis Veterans Affairs Medical Center, St. Louis, MO
| | - Eero Vuoksimaa
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA; Department of Public Health, University of Helsinki, Helsinki, Finland
| | - Kelly M Spoon
- Computational Science Research Center, San Diego State University, San Diego, CA, USA
| | - Sally P Mendoza
- Department of Psychology, University of California, Davis, CA, USA
| | | | | | - Brinda K Rana
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA
| | - Ruth McKenzie
- Department of Psychology, Boston University, Boston, MA, USA
| | - Jeanne M McCaffery
- Department of Psychiatry and Human Behavior, The Miriam Hospital and Warren Alpert School of Medicine at Brown University, Providence, RI, USA
| | - Michael J Lyons
- Department of Psychology, Boston University, Boston, MA, USA
| | - William S Kremen
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA; VA San Diego Healthcare System, CA, USA; Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA, USA
| | - Carol E Franz
- Department of Psychiatry, University of California, San Diego, CA, USA; Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, CA, USA
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15
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Shea YF, Chu LW, Zhou L, Li WM, Lin OY, Chan MNY, Xu A, Wong R, Ho TY, Liu KW, Ha J, Daniel T, Song YQ, Lam KS. Cerebrospinal fluid biomarkers of Alzheimer's disease in Chinese patients: a pilot study. Am J Alzheimers Dis Other Demen 2013; 28:769-75. [PMID: 24085246 PMCID: PMC10852804 DOI: 10.1177/1533317513504615] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2024]
Abstract
In view of the paucity of data on cerebrospinal fluid (CSF) biomarkers in Chinese patients, we evaluated the validity of tau, phosphorylated tau 181 (p-tau-181), amyloid β 42 (Aβ42), and Aβ40 proteins in Chinese patients with Alzheimer's disease (AD). We recruited 24 patients with AD, 12 nondemented controls, and 12 patients with non-AD dementia. We found the CSF levels of Aβ42, tau, p-tau, Aβ42-tau, and Aβ42-p-tau ratios, except the Aβ40 protein level, were significantly different among the 3 groups of patients. Patients with AD had higher levels of CSF tau and p-tau but lower levels of Aβ42 proteins, Aβ42-tau, and Aβ42-p-tau ratios than the nondemented controls. In the diagnosis of AD versus nondementia, the sensitivity and specificity of the ratios of Aβ42-tau and Aβ42-p-tau were 96% and 83% versus 92% and 83%, respectively. Only the Aβ42-p-tau ratio showed satisfactory sensitivity and specificity in the diagnosis of AD versus other dementia.
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Affiliation(s)
- Yat Fung Shea
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Leung-Wing Chu
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
- Research Centre of Heart, Brain, Hormone & Healthy Aging, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong
- Alzheimer’s Disease Research Network, SRT Healthy Aging, The University of Hong Kong, Hong Kong
| | - Lin Zhou
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Wing-Man Li
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Oi Yee Lin
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - May N. Y. Chan
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Aimin Xu
- Department of Medicine, Division of Endocrinology and Metabolism, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Rachel Wong
- Department of Medicine, Division of Endocrinology and Metabolism, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Tip Yin Ho
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Kin Wah Liu
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - Joyce Ha
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - T.W. Daniel
- Division of Geriatrics, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
| | - You-Qiang Song
- Department of Biochemistry, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Karen S. Lam
- Research Centre of Heart, Brain, Hormone & Healthy Aging, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong
- Alzheimer’s Disease Research Network, SRT Healthy Aging, The University of Hong Kong, Hong Kong
- Department of Medicine, Division of Endocrinology and Metabolism, LKS Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong
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Panizzon MS, Hauger R, Jacobson KC, Eaves LJ, York TP, Prom-Wormley E, Grant MD, Lyons MJ, McKenzie R, Mendoza SP, Xian H, Franz CE, Kremen WS. Genetic and environmental influences of daily and intra-individual variation in testosterone levels in middle-aged men. Psychoneuroendocrinology 2013; 38:2163-72. [PMID: 23639251 PMCID: PMC3775872 DOI: 10.1016/j.psyneuen.2013.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 03/27/2013] [Accepted: 04/03/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Testosterone regulates numerous physiological processes, and evidence suggests that it plays a critical role in male aging. It has yet to be determined whether the heritability of testosterone varies in accordance with its diurnal rhythm. Similarly, it is unclear whether changes in testosterone level throughout the day are genetically influenced. The aim of the present study was to determine the degree to which genetic and environmental factors contribute to individual differences in testosterone throughout the day in middle-aged men. METHODS Saliva-based measures of free testosterone, sampled at multiple time-points both at-home and in-lab, were collected from 783 male twins (193 monozygotic pairs, 196 dizygotic pairs, 5 unpaired twins) as part of the Vietnam Era Twin Study of Aging (VETSA). The average age of participants was 55.9 years (SD=2.6). RESULTS Testosterone levels declined substantially over the course of the day, with 32-39% of the change occurring in the first 30min after waking. Heritability estimates for specific time-points ranged from .02 to .39. The heritability of the average at-home and in-lab testosterone values were notably higher (.42 and .47 respectively). Daily rates of change showed some evidence of genetic influence, with heritability estimates ranging from .15 to .29, whereas there were no observable genetic influences on coefficients of variation. CONCLUSIONS Genetic influences account for a significant proportion of the variance in average testosterone levels, while environmental factors account for the majority of intra-individual variability. These results highlight the need to explore both genetic and individual-specific environmental factors as determinants of free testosterone levels in aging men.
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Affiliation(s)
- Matthew S. Panizzon
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, CA,Corresponding Author: Dr. Matthew S. Panizzon, Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive (MC 0738), La Jolla, CA 9293-0738; Tel: 858-534-8269; Fax: 858-822-5856;
| | - Richard Hauger
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA
| | | | - Lindon J. Eaves
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA
| | - Timothy P. York
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA
| | - Elizabeth Prom-Wormley
- Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA
| | | | | | - Ruth McKenzie
- Department of Psychology, Boston University, Boston, MA
| | - Sally P. Mendoza
- Department of Psychology, University of California, Davis, Davis, CA
| | - Hong Xian
- Department of Medicine, Washington University School of Medicine, St. Louis, MO,VA St. Louis Healthcare System, St. Louis, MO
| | - Carol E. Franz
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, CA
| | - William S. Kremen
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, CA,Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA
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Brain testosterone deficiency leads to down-regulation of mitochondrial gene expression in rat hippocampus accompanied by a decline in peroxisome proliferator-activated receptor-γ coactivator 1α expression. J Mol Neurosci 2013; 52:531-7. [PMID: 24005768 DOI: 10.1007/s12031-013-0108-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/27/2013] [Indexed: 10/26/2022]
Abstract
Age-related decrease of testosterone levels in blood and brain is believed to be associated with neurodegenerative diseases such as Alzheimer's disease. However, the effect of testosterone on brain function is not well understood. Therefore, we investigated the impact of testosterone deprivation on mitochondrial gene expression in the brain of male gonadectomized (GDX) rats. We found that peripheral castration led to testosterone deficiency in the brain and caused a significant reduction in protein and mRNA expression of genes encoded by mitochondrial DNA, namely NADPH dehydrogenase subunit 1, subunit 4, cytochrome b, and cytochrome c oxidase subunit 1 and subunit 3 in the hippocampus. In addition, gene expression of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), which is a master regulator of mitochondrial biogenesis, and its downstream transcriptional factors, nuclear respiratory factors 1 and 2 and mitochondrial transcription factors A and B2, were also decreased in the hippocampus of GDX rats. These reductions in the expression of mitochondrial gene and transcriptional coactivators and factors were recovered by androgen replacement. These findings indicate that androgen plays an important role in mitochondrial gene expression in the hippocampus.
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Malmstrom TK, Morley JE. Frailty and cognition: linking two common syndromes in older persons. J Nutr Health Aging 2013; 17:723-5. [PMID: 24154641 DOI: 10.1007/s12603-013-0395-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- T K Malmstrom
- John E. Morley, MB, BCh, Director, Divisions of Geriatric Medicine and Endocrinology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., M238, St. Louis, Missouri 63104,
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Morley JE. Scientific overview of hormone treatment used for rejuvenation. Fertil Steril 2013; 99:1807-13. [DOI: 10.1016/j.fertnstert.2013.04.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/04/2013] [Accepted: 04/05/2013] [Indexed: 01/08/2023]
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Morley JE. Hypogonadism, testosterone, and nursing home residents. J Am Med Dir Assoc 2013; 14:381-3. [PMID: 23647780 DOI: 10.1016/j.jamda.2013.03.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 03/20/2013] [Indexed: 01/10/2023]
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Kalaitzakis E, Josefsson A, Castedal M, Henfridsson P, Bengtsson M, Andersson B, Björnsson E. Hepatic encephalopathy is related to anemia and fat-free mass depletion in liver transplant candidates with cirrhosis. Scand J Gastroenterol 2013; 48:577-84. [PMID: 23452072 DOI: 10.3109/00365521.2013.777468] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Although muscle wasting may lead to decreased ammonia detoxification in cirrhosis, the potential role of lean mass depletion in hepatic encephalopathy (HE) has not been explored. Anemia, hormonal abnormalities, and psychological distress may contribute to cognitive dysfunction, but data on their potential relation to HE are limited. METHODS Data on 108 cirrhotic liver transplant candidates enrolled in a prospective study on fatigue were retrospectively analyzed. HE was assessed clinically and with the number connection tests (NCT) A and B. Psychosocial distress was assessed with a validated questionnaire. Fasting serum glucose, insulin, ammonia, and the glomerular filtration rate (GFR) were measured. Fat and fat-free mass was evaluated with dual-energy X-ray absorptiometry. Serum cortisol, testosterone, dehydroepiandrosterone, thyroid function tests, interleukin-6, and tumor necrosis factor-α (TNF-α) were measured in a subgroup of 80 patients. RESULTS A total of 28% of patients had (overt or minimal) HE. Anemia was present in 59%, diabetes in 29%, renal impairment in 16%, and fat-free mass depletion in 14%. In multivariate analysis, fat-free mass depletion was an independent predictor of HE and NCT-A; renal impairment of NCT-A and -B; and anemia of NCT-B (p < 0.05 for all). HE was also independently related to international normalized ratio and TNF-α (p < 0.05 for both), but not to other hormonal abnormalities or psychological distress. Plasma ammonia was independently associated to anemia (beta = 15.24, p = 0.049), fasting insulin (beta = 0.26, p < 0.05), and GFR (beta = -0.43, p = 0.003). CONCLUSIONS Anemia and fat-free mass depletion are predictors of HE in cirrhotic liver transplant candidates along with liver failure, renal impairment, and systemic inflammation.
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Affiliation(s)
- Evangelos Kalaitzakis
- Institute of Internal Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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22
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Samaras N, Samaras D, Lang PO, Forster A, Pichard C, Frangos E, Meyer P. A view of geriatrics through hormones. What is the relation between andropause and well-known geriatric syndromes? Maturitas 2013; 74:213-9. [DOI: 10.1016/j.maturitas.2012.11.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Revised: 10/24/2012] [Accepted: 11/21/2012] [Indexed: 11/29/2022]
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Giton F, Guéchot J, Fiet J. Comparative determinations of non SHBG-bound serum testosterone, using ammonium sulfate precipitation, Concanavalin A binding or calculation in men. Steroids 2012; 77:1306-11. [PMID: 22542501 DOI: 10.1016/j.steroids.2012.04.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 03/29/2012] [Accepted: 04/06/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Testosterone (T) circulates tightly bound to sex hormone-binding globulin (SHBG) and weakly to albumin. Non-SHBG-bound T is considered as the bioavailable T (BT) and was recommended for the evaluation of androgen disorders. Two methods, BT calculating from T, SHBG and albumin or BT measurement using ammonium sulfate precipitation of [SHBG-T] complex have been widely used. Using SHBG separation with Concanavalin-A (ConA) was recently proposed as a more specific method. The aim of this work was to compare these three methods in male patients. METHODS Serum samples of 131 consecutive untreated men (15-81 years) referred for suspicion of hypogonadism were collected. Total T was measured by GC-MS, SHBG by immunoradiometric assay. Level of BT was assayed using ammonium sulfate precipitation, ConA separation and calculated using the Issam web calculator. RESULTS Only few differences were found between ammonium sulfate or ConA BT measurements. However, we found much higher serum calculated BT than assayed BT with an increasing bias when BT levels increased. CONCLUSIONS Measurement of BT using ConA separation could be recommended. The results are equivalent to those obtained using ammonium sulfate precipitation. This method eliminates the possible non specific albumin precipitation that can occur with ammonium sulfate when the assay conditions are not rigorously controlled.
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Affiliation(s)
- Frank Giton
- AP-HP, Hôpital H. Mondor - A.Chenevier, Pôle Biologie, Centre d'investigation Biologique 006, Créteil 94000, France
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Drummond ES, Martins RN, Handelsman DJ, Harvey AR. Altered expression of Alzheimer's disease-related proteins in male hypogonadal mice. Endocrinology 2012; 153:2789-99. [PMID: 22514046 DOI: 10.1210/en.2011-2003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Age-related depletion of estrogens and androgens is associated with an increase in Alzheimer's disease (AD) brain pathology and diminished cognitive function. Here we investigated AD-associated molecular and cellular changes in brains of aged hypogonadal (hpg) male and female mice. hpg Mice have a spontaneous, inactivating genetic mutation in the GnRH gene resulting in life-long deficiency of gonadotropins and gonadal sex hormones. Western blot analysis revealed low levels of amyloid precursor protein and high levels of presenilin 1, amyloid precursor protein C-terminal fragment, and β-amyloid 42 in brains of aged male, but not female, hpg mice. Changes were confined to the hippocampus and were not evident in the cerebellum or other brain tissues. Male hpg mice tended to have lower levels of IL-1β protein than male littermate controls. Immunohistochemical staining of the basal forebrain revealed that male hpg mice had lower choline acetyltransferase levels per neuron compared with controls. These AD-like changes specific to male hpg mice supports a link between androgen depletion and the development of AD pathology.
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Affiliation(s)
- Eleanor S Drummond
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Western Australia, 6009 Australia.
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Morley JE, Armbrecht HJ, Farr SA, Kumar VB. The senescence accelerated mouse (SAMP8) as a model for oxidative stress and Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2012; 1822:650-6. [DOI: 10.1016/j.bbadis.2011.11.015] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 11/11/2011] [Accepted: 11/12/2011] [Indexed: 12/11/2022]
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Maggio M, Dall'Aglio E, Lauretani F, Cattabiani C, Ceresini G, Caffarra P, Valenti G, Volpi R, Vignali A, Schiavi G, Ceda GP. The hormonal pathway to cognitive impairment in older men. J Nutr Health Aging 2012; 16:40-54. [PMID: 22238001 DOI: 10.1007/s12603-012-0002-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In older men there is a multiple hormonal dysregulation with a relative prevalence of catabolic hormones such as thyroid hormones and cortisol and a decline in anabolic hormones such as dehydroepiandrosterone sulphate, testosterone and insulin like growth factor 1 levels. Many studies suggest that this catabolic milieu is an important predictor of frailty and mortality in older persons. There is a close relationship between frailty and cognitive impairment with studies suggesting that development of frailty is consequence of cognitive impairment and others pointing out that physical frailty is a determinant of cognitive decline. Decline in cognitive function, typically memory, is a major symptom of dementia. The "preclinical phase" of cognitive impairment occurs many years before the onset of dementia. The identification of relevant modifiable factors, including the hormonal dysregulation, may lead to therapeutic strategies for preventing the cognitive dysfunction. There are several mechanisms by which anabolic hormones play a role in neuroprotection and neuromodulation. These hormones facilitate recovery after brain injury and attenuate the neuronal loss. In contrast, elevated thyroid hormones may increase oxidative stress and apoptosis, leading to neuronal damage or death. In this mini review we will address the relationship between low levels of anabolic hormones, changes in thyroid hormones and cognitive function in older men. Then, giving the contradictory data of the literature and the multi-factorial origin of dementia, we will introduce the hypothesis of multiple hormonal derangement as a better determinant of cognitive decline in older men.
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Affiliation(s)
- M Maggio
- Department of Internal Medicine and Biomedical Sciences, Section of Geriatrics, University of Parma, Parma, Italy.
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Genetic influences on hippocampal volume differ as a function of testosterone level in middle-aged men. Neuroimage 2011; 59:1123-31. [PMID: 21983185 DOI: 10.1016/j.neuroimage.2011.09.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 09/18/2011] [Accepted: 09/19/2011] [Indexed: 11/23/2022] Open
Abstract
The hippocampus expresses a large number of androgen receptors; therefore, in men it is potentially vulnerable to the gradual age-related decline of testosterone levels. In the present study we sought to elucidate the nature of the relationship between testosterone and hippocampal volume in a sample of middle-aged male twins (average age 55.8 years). We found no evidence for a correlation between testosterone level and hippocampal volume, as well as no indication of shared genetic influences. However, a significant moderating effect of testosterone on the genetic and environmental determinants of hippocampal volume was observed. Genetic influences on hippocampal volume increased substantially as a function of increasing testosterone level, while environmental influences either decreased or remained stable. These findings provide evidence for an apparent gene-by-hormone interaction on hippocampal volume. To the best of our knowledge, this is the first study to demonstrate that the heritability of a brain structure in adults may be modified by an endogenous biological factor.
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Testosterone levels and cognition in elderly men: a review. Maturitas 2011; 69:322-37. [PMID: 21696899 DOI: 10.1016/j.maturitas.2011.05.012] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 05/22/2011] [Indexed: 11/24/2022]
Abstract
Average testosterone levels and many cognitive functions show a decline with age. There is evidence to suggest that this association is not just age related. Results from cell culture and animal studies provide convincing evidence that testosterone could have protective effects on brain function. Alzheimer's disease (AD) is characterised by brain pathology affecting cognitive function and AD prevalence increases with age. Testosterone levels are lower in AD cases compared to controls, and some studies have suggested that low free testosterone (FT) may precede AD onset. Men with AD may show accelerated endocrinological ageing, characterised by an earlier lowering of thyroid stimulating hormone, an earlier increase in sex hormone binding globulin (SHBG), a subsequent earlier decrease in FT and an earlier increase in gonadotropin levels in response to this. Positive associations have been found between testosterone levels and global cognition, memory, executive functions and spatial performance in observational studies. However, non-significant associations were also reported. It may be that an optimal level of testosterone exists at which some cognitive functions are improved. This may be modified with an older age, with a shifting of the optimal testosterone curve to maintain cognition to the left and a lower optimal level thus needed to be beneficial for the brain. Genetic factors, such as APOE and CAG polymorphisms may further interact with testosterone levels in their effects on cognition. The roles of SHBG, gonadotropins, thyroid hormones and estrogens in maintaining cognitive function and preventing dementia in men are also not completely understood and should be investigated further. Hypogonadal men do not seem to benefit from testosterone supplementation but small scale, short term intervention studies in eugonadal men with and without cognitive impairments have shown promising results. Larger randomised, controlled trials are needed to further investigate testosterone treatment in protecting against cognitive decline and/or dementia.
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Panizzon MS, Hauger R, Dale AM, Eaves LJ, Eyler LT, Fischl B, Fennema-Notestine C, Franz CE, Grant MD, Jak AJ, Jacobson KC, Lyons MJ, Mendoza SP, Neale MC, Prom-Wormley EC, Seidman LJ, Tsuang MT, Xian H, Kremen WS. Testosterone modifies the effect of APOE genotype on hippocampal volume in middle-aged men. Neurology 2010; 75:874-80. [PMID: 20819998 DOI: 10.1212/wnl.0b013e3181f11deb] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The APOE epsilon4 allele is an established risk factor for Alzheimer disease (AD), yet findings are mixed for how early its effects are manifest. One reason for the mixed results could be the presence of interaction effects with other AD risk factors. Increasing evidence indicates that testosterone may play a significant role in the development of AD. The aim of the present study was to examine the potential interaction of testosterone and APOE genotype with respect to hippocampal volume in middle age. METHODS Participants were men from the Vietnam Era Twin Study of Aging (n = 375). The mean age was 55.9 years (range 51-59). Between-group comparisons were performed utilizing a hierarchical linear mixed model that adjusted for the nonindependence of twin data. RESULTS A significant interaction was observed between testosterone and APOE genotype (epsilon4-negative vs epsilon4-positive). Those with both low testosterone (> or =1 SD below the mean) and an epsilon4-positive status had the smallest hippocampal volumes, although comparisons with normal testosterone groups were not significant. However, individuals with low testosterone and epsilon4-negative status had significantly larger hippocampal volumes relative to all other groups. A main effect of APOE genotype on hippocampal volume was observed, but only when the APOE-by-testosterone interaction was present. CONCLUSIONS These findings demonstrate an interaction effect between testosterone and the APOE epsilon4 allele on hippocampal volume in middle-aged men, and they may suggest 2 low testosterone subgroups. Furthermore, these results allude to potential gene-gene interactions between APOE and either androgen receptor polymorphisms or genes associated with testosterone production.
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Affiliation(s)
- M S Panizzon
- Department of Psychiatry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 9293-0738, USA.
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Abstract
Increased longevity and population aging will increase the number of men with late-onset hypogonadism, a common condition that is often under diagnosed and under treated. The indication of testosterone replacement therapy (TRT) treatment requires the presence of low testosterone level and symptoms and signs of hypogonadism. Although there is a lack of large-scale, long-term studies assessing the benefits and risks of TRT in men with hypogonadism, reports indicate that TRT may produce a wide range of benefits that include improvement in libido and sexual function, bone density, muscle mass, body composition, mood, erythropoiesis, cognition, quality of life, and cardiovascular disease. Perhaps the most controversial area is the issue of risk, especially the possible stimulation of prostate cancer by testosterone, even though there is no evidence to support this risk. Other possible risks include worsening symptoms of benign prostatic hypertrophy, liver toxicity, hyperviscosity, erythrocytosis, worsening untreated sleep apnea, or severe heart failure. Despite this controversy, testosterone supplementation in the United States has increased substantially in the past several years. The physician should discuss with the patient the potential benefits and risks of TRT. This review discusses the benefits and risks of TRT.
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Affiliation(s)
- Nazem Bassil
- Division of Geriatric Psychiatry, Department of Neurology and Psychiatry, Saint Louis University School of Medicine, St Louis, MO 63104, USA
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Morley JE. Preface: The aging male. Clin Geriatr Med 2010; 26:xi-xii. [PMID: 20497838 DOI: 10.1016/j.cger.2010.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- John E Morley
- Division of Geriatric Medicine, Saint Louis University School of Medicine, 1402 South Grand Boulevard, M238, St Louis, MO 63104, USA.
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Aging male. Clin Geriatr Med 2010; 26:171-84. [PMID: 20497839 DOI: 10.1016/j.cger.2010.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There are several special issues that confront the physician when dealing with the older male. Physicians need to pay attention to these issues and recognize their importance to their patients. This article briefly reviews these unique challenges.
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Abstract
PURPOSE OF REVIEW The role of calorie restriction in humans is controversial. Recently, new data in monkeys and humans have provided new insights into the potential role of calorie restriction in longevity. RECENT FINDINGS A study in rhesus monkeys showed a reduction in aging-associated mortality. A number of controlled studies have suggested a variety of beneficial effects during studies of 6-12 months in humans. Major negative effects in humans were loss of muscle mass, muscle strength and loss of bone. SUMMARY Dietary restriction in rodents has not been shown to be effective when started in older rodents. Weight loss in humans over 60 years of age is associated with increased mortality, hip fracture and increased institutionalization. Calorie restriction in older persons should be considered experimental and potentially dangerous. Exercise at present appears to be a preferable treatment for older persons.
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Young LA, Neiss MB, Samuels MH, Roselli CE, Janowsky JS. Cognition is not modified by large but temporary changes in sex hormones in men. J Clin Endocrinol Metab 2010; 95:280-8. [PMID: 19880786 PMCID: PMC2805481 DOI: 10.1210/jc.2009-1346] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Little is known about the role of testosterone and estradiol on cognition in healthy older men. OBJECTIVE The cognitive effects of increasing or lowering testosterone or estradiol were examined. DESIGN Cognition was assessed before and after 6 wk of double-blind placebo-controlled hormone modification. SETTING The study was conducted at an academic medical center. PARTICIPANTS Healthy older (ages 60-80 yr) and younger men (ages 25-35 yr) were recruited from the community. INTERVENTION Men were randomized to one of four treatments: 1) maintain testosterone and estradiol at eugonadal levels for young men (GnRH agonist + testosterone gel); 2) block testosterone's conversion to estradiol (GnRH agonist + testosterone gel + aromatase inhibitor); 3) induce hypogonadism (GnRH agonist alone); and 4) all placebo. MAIN OUTCOME MEASURES Measures of executive function, memory, and spatial cognition were obtained before and after treatment. Hormone levels were obtained 10 times over the course of the study. RESULTS Counter to expectations, hormone treatment did not affect cognition (P > 0.10). Free testosterone was positively related to spatial cognition in older men after treatment and controlling for age and estradiol level or exclusion of the hypogonadal men (P = 0.02). Estradiol was negatively associated with working memory controlling for the same variables (P = 0.01). Blinding to treatment assignment was maintained, with the exception of the hypogonadal group. CONCLUSIONS A significant change in sex hormone status, including complete hypogonadism, does not modify cognition in men. These findings, along with studies that show a risk for neurodegenerative disease in those with low testosterone, suggest that sex hormone status may be important for neuroprotection in aging but not modulation of normal day-to-day cognitive function.
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Affiliation(s)
- Laura A Young
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon 97239-3098, USA
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Current world literature. Curr Opin Endocrinol Diabetes Obes 2009; 16:260-77. [PMID: 19390324 DOI: 10.1097/med.0b013e32832c937e] [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: 11/27/2022]
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Bassil N, Alkaade S, Morley JE. The benefits and risks of testosterone replacement therapy: a review. Ther Clin Risk Manag 2009; 5:427-48. [PMID: 19707253 PMCID: PMC2701485 DOI: 10.2147/tcrm.s3025] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Indexed: 12/13/2022] Open
Abstract
Increased longevity and population aging will increase the number of men with late onset hypogonadism. It is a common condition, but often underdiagnosed and undertreated. The indication of testosterone-replacement therapy (TRT) treatment requires the presence of low testosterone level, and symptoms and signs of hypogonadism. Although controversy remains regarding indications for testosterone supplementation in aging men due to lack of large-scale, long-term studies assessing the benefits and risks of testosterone-replacement therapy in men, reports indicate that TRT may produce a wide range of benefits for men with hypogonadism that include improvement in libido and sexual function, bone density, muscle mass, body composition, mood, erythropoiesis, cognition, quality of life and cardiovascular disease. Perhaps the most controversial area is the issue of risk, especially possible stimulation of prostate cancer by testosterone, even though no evidence to support this risk exists. Other possible risks include worsening symptoms of benign prostatic hypertrophy, liver toxicity, hyperviscosity, erythrocytosis, worsening untreated sleep apnea or severe heart failure. Despite this controversy, testosterone supplementation in the United States has increased substantially over the past several years. The physician should discuss with the patient the potential benefits and risks of TRT. The purpose of this review is to discuss what is known and not known regarding the benefits and risks of TRT.
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Affiliation(s)
| | - Saad Alkaade
- Internal Medicine, Saint Louis University Health Sciences Center, St. Louis, Missouri, USA
| | - John E Morley
- Division of Geriatric Medicine
- GRECC, VA Medical Center, St. Louis, Missouri, USA
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Abstract
PURPOSE OF REVIEW To discuss the relationship between androgens, cognition and Alzheimer's disease. RECENT FINDINGS It has been found that low circulating levels of androgens are a risk factor for Alzheimer's disease. Decreased circulating androgens are also associated with declining cognitive performance, particularly in memory-related tasks. Conversely, androgen supplementation to hypogonadal men results in improved memory performance. It has therefore been hypothesized that androgen supplementation may be beneficial in Alzheimer's disease. In recent studies, animal models have been used to elucidate the molecular mechanism behind this relationship between androgens and Alzheimer's disease. These studies have shown that androgen depletion results in increased levels of beta amyloid and hyperphosphorylated tau, changes which are thought to be associated with subsequent neuronal death. SUMMARY Androgen depletion results in molecular changes associated with Alzheimer's disease. Further human trials are needed to determine whether androgen modulating therapy for Alzheimer's disease has clinical significance.
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Affiliation(s)
- Eleanor S Drummond
- School of Anatomy and Human Biology, The University of Western Australia, Crawley, Australia
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