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Dratva MA, Banks SJ, Panizzon MS, Galasko D, Sundermann EE. Low testosterone levels relate to poorer cognitive function in women in an APOE-ε4-dependant manner. Biol Sex Differ 2024; 15:45. [PMID: 38835072 DOI: 10.1186/s13293-024-00620-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 05/15/2024] [Indexed: 06/06/2024] Open
Abstract
BACKGROUND Past research suggests that low testosterone levels relate to poorer cognitive function and higher Alzheimer's disease (AD) risk; however, these findings are inconsistent and are mostly derived from male samples, despite similar age-related testosterone decline in females. Both animal and human studies demonstrate that testosterone's effects on brain health may be moderated by apolipoprotein E ε4 allele (APOE-ε4) carrier status, which may explain some previous inconsistencies. We examined how testosterone relates to cognitive function in older women versus men across healthy aging and the AD continuum and the moderating role of APOE-ε4 genotype. METHODS Five hundred and sixty one participants aged 55-90 (155 cognitively normal (CN), 294 mild cognitive impairment (MCI), 112 AD dementia) from the Alzheimer's Disease Neuroimaging Initiative (ADNI), who had baseline cognitive and plasma testosterone data, as measured by the Rules Based Medicine Human DiscoveryMAP Panel were included. There were 213 females and 348 males (self-reported sex assigned at birth), and 52% of the overall sample were APOE-ε4 carriers. We tested the relationship of plasma testosterone levels and its interaction with APOE-ε4 status on clinical diagnostic group (CN vs. MCI vs. AD), global, and domain-specific cognitive performance using ANOVAs and linear regression models in sex-stratified samples. Cognitive domains included verbal memory, executive function, processing speed, and language. RESULTS We did not observe a significant difference in testosterone levels between clinical diagnostic groups in either sex, regrardless of APOE-ε4 status. Across clinical diagnostic group, we found a significant testosterone by APOE-ε4 interaction in females, such that lower testosterone levels related to worse global cognition, processing speed, and verbal memory in APOE-ε4 carriers only. We did not find that testosterone, nor its interaction with APOE-ε4, related to cognitive outcomes in males. CONCLUSIONS Findings suggest that low testosterone levels in older female APOE-ε4 carriers across the aging-MCI-AD continuum may have deleterious, domain-specific effects on cognitive performance. Although future studies including additional sex hormones and longitudinal cognitive trajectories are needed, our results highlight the importance of including both sexes and considering APOE-ε4 carrier status when examining testosterone's role in cognitive health.
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Affiliation(s)
- Melanie A Dratva
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA.
- UCSD ACTRI Building, 2W502-B8, 9452 Medical Center Drive (MC-0841), La Jolla, CA, 92037, USA.
| | - Sarah J Banks
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Matthew S Panizzon
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
- Center for Behavior Genetics of Aging, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92092, USA
| | - Douglas Galasko
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Erin E Sundermann
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
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2
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Espeland MA, Howard M, Bennett W, Robusto BA, Yasar S, Hugenschmidt CE, Luchsinger JA, Bahnson J, Yassine H, Johnson KC, Cook D, Hayden KM. Associations between cognitive function and endogenous levels of estradiol and testosterone in adults with type 2 diabetes. J Diabetes Complications 2022; 36:108268. [PMID: 35926332 PMCID: PMC10162709 DOI: 10.1016/j.jdiacomp.2022.108268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 10/16/2022]
Abstract
AIMS To assess associations that endogenous estradiol and testosterone levels have with cognitive function in older adults with Type 2 diabetes mellitus (T2DM). METHODS We use data from the Look AHEAD clinical trial of behavioral weight loss. Endogenous estradiol and total testosterone levels were determined using stored serum from 996 individuals, mean age 69 years, at two times (averaging 4 years apart) during years 8-18 of follow-up. One to four standardized assessments of attention, executive function, memory, and verbal fluency were collected during this follow-up. Mixed effects models and multiple imputation were used to assess associations that estradiol and total testosterone levels had with body mass index and cognitive function. RESULTS Estradiol levels were not associated with cognitive function in either sex. Total testosterone levels were not associated with cognitive function in women, but greater total testosterone levels were associated with better verbal fluency in men (p < 0.001), most strongly among those carrying the APOE-e4 allele (interaction p = 0.02). The weight loss intervention left a legacy of relatively lower cognitive functioning among women, which was not mediated by current levels of sex hormones. CONCLUSIONS Behavioral weight loss intervention does not affect cognitive functioning through mechanisms related to estradiol or testosterone. CLINICALTRIALS gov Identifier: NCT00017953.
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Affiliation(s)
- Mark A Espeland
- Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA; Department of Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, NC, USA; Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Marjorie Howard
- Department of Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Wendy Bennett
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.
| | - Brian A Robusto
- Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Sevil Yasar
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.
| | - Christina E Hugenschmidt
- Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Jose A Luchsinger
- Department of Medicine, Columbia University Medical Center, New York, NY, USA.
| | - Judy Bahnson
- Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Hussein Yassine
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| | - Karen C Johnson
- Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
| | - Delilah Cook
- Department of Biostatistics and Data Science, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Kathleen M Hayden
- Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, NC, USA.
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3
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Yao M, Rosario ER, Soper JC, Pike CJ. Androgens Regulate Tau Phosphorylation Through Phosphatidylinositol 3-Kinase-Protein Kinase B-Glycogen Synthase Kinase 3β Signaling. Neuroscience 2022:S0306-4522(22)00335-9. [PMID: 35777535 PMCID: PMC9797620 DOI: 10.1016/j.neuroscience.2022.06.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/11/2022] [Accepted: 06/23/2022] [Indexed: 12/31/2022]
Abstract
Age-related testosterone depletion in men is a risk factor for Alzheimer's disease (AD). How testosterone modulates AD risk remains to be fully elucidated, although regulation of tau phosphorylation has been suggested as a contributing protective action. To investigate the relationship between testosterone and tau phosphorylation, we first evaluated the effect of androgen status on tau phosphorylation in 3xTg-AD mice. Depletion of endogenous androgens via gonadectomy resulted in increased tau phosphorylation that was prevented by acute testosterone treatment. Parallel alterations in the phosphorylation of both glycogen synthase kinase 3β (GSK3β) and protein kinase B (Akt) suggest possible components of the underlying signaling pathway. To further explore mechanism, primary cultured neurons were treated with a physiological concentration of testosterone or its active metabolite dihydrotestosterone (DHT). Results showed that testosterone and DHT induced significant decreases in phosphorylated tau and significant increases in phosphorylation of Akt and GSK3β. Pharmacological inhibition of phosphatidylinositol 3-kinase (PI3K) effectively inhibited androgen-induced increases in Akt and GSK3β phosphorylation, and decreases in tau phosphorylation. In addition, androgen receptor (AR) knock-down by small interfering RNA prevented androgen-induced changes in the phosphorylation of Akt, GSK3β and tau, suggesting an AR-dependent mechanism. Additional experiments demonstrated androgen-induced changes in Akt, GSK3β and tau phosphorylation in AR-expressing PC12 cells but not in AR-negative PC12 cells. Together, these results suggest an AR-dependent pathway involving PI3K-Akt-GSK3β signaling through which androgens can reduce tau phosphorylation. These findings identify an additional protective mechanism of androgens that can improve neural health and inhibit development of AD.
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Affiliation(s)
- Mingzhong Yao
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Emily R Rosario
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Jenna Carroll Soper
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Christian J Pike
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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4
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Blankers SA, Galea LA. Androgens and Adult Neurogenesis in the Hippocampus. ANDROGENS: CLINICAL RESEARCH AND THERAPEUTICS 2021; 2:203-215. [PMID: 35024692 PMCID: PMC8744005 DOI: 10.1089/andro.2021.0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/19/2021] [Indexed: 11/12/2022]
Abstract
Adult neurogenesis in the hippocampus is modulated by steroid hormones, including androgens, in male rodents. In this review, we summarize research showing that chronic exposure to androgens, such as testosterone and dihydrotestosterone, enhances the survival of new neurons in the dentate gyrus of male, but not female, rodents, via the androgen receptor. However, the neurogenesis promoting the effect of androgens in the dentate gyrus may be limited to younger adulthood as it is not evident in middle-aged male rodents. Although direct exposure to androgens in adult or middle age does not significantly influence neurogenesis in female rodents, the aromatase inhibitor letrozole enhances neurogenesis in the hippocampus of middle-aged female mice. Unlike other androgens, androgenic anabolic steroids reduce neurogenesis in the hippocampus of male rodents. Collectively, the research indicates that the ability of androgens to enhance hippocampal neurogenesis in adult rodents is dependent on dose, androgen type, sex, duration, and age. We discuss these findings and how androgens may be influencing neuroprotection, via neurogenesis in the hippocampus, in the context of health and disease.
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Affiliation(s)
- Samantha A. Blankers
- Graduate Program in Neuroscience, The University of British Columbia, Vancouver, Canada
- Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, Canada
| | - Liisa A.M. Galea
- Graduate Program in Neuroscience, The University of British Columbia, Vancouver, Canada
- Djavad Mowafaghian Centre for Brain Health, The University of British Columbia, Vancouver, Canada
- Department of Psychology, The University of British Columbia, Vancouver, Canada
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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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Gamache J, Yun Y, Chiba-Falek O. Sex-dependent effect of APOE on Alzheimer's disease and other age-related neurodegenerative disorders. Dis Model Mech 2020; 13:dmm045211. [PMID: 32859588 PMCID: PMC7473656 DOI: 10.1242/dmm.045211] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The importance of apolipoprotein E (APOE) in late-onset Alzheimer's disease (LOAD) has been firmly established, but the mechanisms through which it exerts its pathogenic effects remain elusive. In addition, the sex-dependent effects of APOE on LOAD risk and endophenotypes have yet to be explained. In this Review, we revisit the different aspects of APOE involvement in neurodegeneration and neurological diseases, with particular attention to sex differences in the contribution of APOE to LOAD susceptibility. We discuss the role of APOE in a broader range of age-related neurodegenerative diseases, and summarize the biological factors linking APOE to sex hormones, drawing on supportive findings from rodent models to identify major mechanistic themes underlying the exacerbation of LOAD-associated neurodegeneration and pathology in the female brain. Additionally, we list sex-by-genotype interactions identified across neurodegenerative diseases, proposing APOE variants as a shared etiology for sex differences in the manifestation of these diseases. Finally, we present recent advancements in 'omics' technologies, which provide a new platform for more in-depth investigations of how dysregulation of this gene affects the development and progression of neurodegenerative diseases. Collectively, the evidence summarized in this Review highlights the interplay between APOE and sex as a key factor in the etiology of LOAD and other age-related neurodegenerative diseases. We emphasize the importance of careful examination of sex as a contributing factor in studying the underpinning genetics of neurodegenerative diseases in general, but particularly for LOAD.
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Affiliation(s)
- Julia Gamache
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27708, USA
| | - Young Yun
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27708, USA
| | - Ornit Chiba-Falek
- Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC 27710, USA
- Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC 27708, USA
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7
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Sundermann EE, Panizzon MS, Chen X, Andrews M, Galasko D, Banks SJ. Sex differences in Alzheimer's-related Tau biomarkers and a mediating effect of testosterone. Biol Sex Differ 2020; 11:33. [PMID: 32560743 PMCID: PMC7304096 DOI: 10.1186/s13293-020-00310-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/12/2020] [Indexed: 02/06/2023] Open
Abstract
Women show greater pathological Tau biomarkers than men along the Alzheimer's disease (AD) continuum, particularly among apolipoprotein ε-E4 (APOE4) carriers; however, the reason for this sex difference in unknown. Sex differences often indicate an underlying role of sex hormones. We examined whether testosterone levels might influence this sex difference and the modifying role of APOE4 status. Analyses included 172 participants (25 cognitively normal, 97 mild cognitive impairment, 50 AD participants) from the Alzheimer's Disease Neuroimaging Initiative (34% female, 54% APOE4 carriers, aged 55-90). We examined the separate and interactive effects of plasma testosterone levels and APOE4 on cerebrospinal fluid phosphorylated-tau181 (p-Tau) levels in the overall sample and the sex difference in p-Tau levels before and after adjusting for testosterone. A significant APOE4-by-testosterone interaction revealed that lower testosterone levels related to higher p-Tau levels among APOE4 carriers regardless of sex. As expected, women had higher p-Tau levels than men among APOE4 carriers only, yet this difference was eliminated upon adjustment for testosterone. Results suggest that testosterone is protective against p-Tau particularly among APOE4 carriers. The lower testosterone levels that typically characterize women may predispose them to pathological Tau, particularly among female APOE4 carriers.
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Affiliation(s)
- Erin E. Sundermann
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093 USA
| | - Matthew S. Panizzon
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093 USA
| | - Xu Chen
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093 USA
| | - Murray Andrews
- Department of Neuroscience, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
| | - Douglas Galasko
- Department of Neuroscience, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
| | - Sarah J. Banks
- Department of Neuroscience, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
| | - for the Alzheimer’s Disease Neuroimaging Initiative
- Department of Psychiatry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093 USA
- Department of Neuroscience, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093 USA
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8
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Narayan V, Harrison M, Cheng H, Kenfield S, Aggarwal R, Kwon D, McKay R, Hauger R, Hart N, Conzen S, Borno H, Jim H, Dicker A, Dorff T, Moslehi J, Mucci L, Parsons JK, Saad F, Soule H, Morgans A, Ryan CJ. Improving research for prostate cancer survivorship: A statement from the Survivorship Research in Prostate Cancer (SuRECaP) working group. Urol Oncol 2020; 38:83-93. [DOI: 10.1016/j.urolonc.2019.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/16/2019] [Accepted: 10/08/2019] [Indexed: 12/26/2022]
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Abstract
The Vietnam Era Twin Study of Aging (VETSA) is a longitudinal behavioral genetic study with a primary focus on cognitive and brain aging in men, particularly early identification of risk for mild cognitive impairment (MCI) and Alzheimer's disease (AD). It comprises a subset of over 1600 twins from the Vietnam Era Twin Registry. Twins live all over the USA. Assessments began when participants were in their 50s. Follow-ups were conducted every 5-6 years, and wave 3 has been completed as of this writing. The age range of participants is narrow (about 10 years). An extensive neurocognitive test battery has added precision in assessing differences in middle-aged adults, and predicting progression to MCI. Young adult cognitive test data (at an average age of 20 years) provide a means of disentangling aging effects from longstanding differences. Genome wide genotyping and plasma assays of AD biomarkers from waves 1 and 3 were conducted in wave 3. These features make the VETSA ideal for studying the heterogeneity of within-individual trajectories from midlife to old age, and for early detection of risk factors for cognitive decline.
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Smeeth DM, Dima D, Jones L, Jones I, Craddock N, Owen MJ, Rietschel M, Maier W, Korszun A, Rice JP, Mors O, Preisig M, Uher R, Lewis CM, Thuret S, Powell TR. Polygenic risk for circulating reproductive hormone levels and their influence on hippocampal volume and depression susceptibility. Psychoneuroendocrinology 2019; 106:284-292. [PMID: 31039525 PMCID: PMC6597945 DOI: 10.1016/j.psyneuen.2019.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 04/04/2019] [Accepted: 04/09/2019] [Indexed: 12/13/2022]
Abstract
Altered reproductive hormone levels have been associated with the pathophysiology of depressive disorders and this risk may be imparted by their modulatory effect upon hippocampal structure and function. Currently it is unclear whether altered levels of reproductive hormones are causally associated with hippocampal volume reductions and the risk of depressive disorders. Here, we utilize genome-wide association study (GWAS) summary statistics from a GWAS focusing on reproductive hormones, consisting of 2913 individuals. Using this data, we generated polygenic risk scores (PRS) for estradiol, progesterone, prolactin and testosterone in the European RADIANT cohort consisting of 176 postpartum depression (PPD) cases (100% female, mean age: 41.6 years old), 2772 major depressive disorder (MDD) cases (68.6% female, mean age: 46.9 years old) and 1588 control participants (62.5% female, mean age: 42.4 years old), for which there was also a neuroimaging subset of 111 individuals (60.4% female, mean age: 50.0 years old). Only the best-fit PRS for estradiol showed a significant negative association with hippocampal volume, as well as many of its individual subfields; including the molecular layer and granule cell layer of the dentate gyrus, subiculum, CA1, CA2/3 and CA4 regions. Interestingly, several of these subfields are implicated in adult hippocampal neurogenesis. When we tested the same estradiol PRS for association with case-control status for PPD or MDD there was no significant relationship observed. Here, we provide evidence that genetic risk for higher plasma estradiol is negatively associated with hippocampal volume, but this does not translate into an increased risk of MDD or PPD. This work suggests that the relationship between reproductive hormones, the hippocampus, and depression is complex, and that there may not be a clear-cut pathway for etiology or risk moderation.
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Affiliation(s)
- Demelza M Smeeth
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Danai Dima
- Department of Psychology, School of Arts and Social Sciences, City, University of London, London, UK; Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Lisa Jones
- Institute of Health & Society, University of Worcester, Worcester, UK
| | - Ian Jones
- MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK
| | - Nick Craddock
- MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK
| | - Michael J Owen
- MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, UK
| | - Marcella Rietschel
- Department of Psychiatry, University of Bonn, Bonn, Germany; Division of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health, Mannheim, Germany
| | - Wolfgang Maier
- Department of Psychiatry, University of Bonn, Bonn, Germany
| | - Ania Korszun
- Barts and The London Medical School, Queen Mary University of London, London, UK
| | - John P Rice
- Department of Psychiatry, Washington University, St. Louis, Missouri, USA
| | - Ole Mors
- Psychosis Research Unit, Aarhus University Hospital, Risskov, Denmark
| | - Martin Preisig
- University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Rudolf Uher
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Cathryn M Lewis
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Sandrine Thuret
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Timothy R Powell
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
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11
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Lambert K, Eisch AJ, Galea LAM, Kempermann G, Merzenich M. Optimizing brain performance: Identifying mechanisms of adaptive neurobiological plasticity. Neurosci Biobehav Rev 2019; 105:60-71. [PMID: 31356835 DOI: 10.1016/j.neubiorev.2019.06.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 06/18/2019] [Accepted: 06/24/2019] [Indexed: 01/19/2023]
Abstract
Although neuroscience research has debunked the late 19th century claims suggesting that large portions of the brain are typically unused, recent evidence indicates that an enhanced understanding of neural plasticity may lead to greater insights related to the functional capacity of brains. Continuous and real-time neural modifications in concert with dynamic environmental contexts provide opportunities for targeted interventions for maintaining healthy brain functions throughout the lifespan. Neural design, however, is far from simplistic, requiring close consideration of context-specific and other relevant variables from both species and individual perspectives to determine the functional gains from increased and decreased markers of neuroplasticity. Caution must be taken in the interpretation of any measurable change in neurobiological responses or behavioral outcomes, as definitions of optimal functions are extremely complex. Even so, current behavioral neuroscience approaches offer unique opportunities to evaluate adaptive functions of various neural responses in an attempt to enhance the functional capacity of neural systems.
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Affiliation(s)
- Kelly Lambert
- Dept of Psychology, B326 Gottwald Science Center, University of Richmond, VA, 23173, USA.
| | - Amelia J Eisch
- Dept of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104-4399, USA.
| | - Liisa A M Galea
- Dept of Psychology, University of British Columbia, 2136 West Mall, Vancouver, BC V6T, Canada.
| | - Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) Dresden and CRTD-Center for Regenerative Therapies Dresden at Technische Universität Dresden, 01307 Dresden, Germany.
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12
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Ahmad MH, Fatima M, Mondal AC. Role of Hypothalamic-Pituitary-Adrenal Axis, Hypothalamic-Pituitary-Gonadal Axis and Insulin Signaling in the Pathophysiology of Alzheimer's Disease. Neuropsychobiology 2019; 77:197-205. [PMID: 30605907 DOI: 10.1159/000495521] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/13/2018] [Indexed: 11/19/2022]
Abstract
Alzheimer's disease (AD), the commonest progressive neurodegenerative disorder of the brain, is clinically characterized by the formation of extracellular amyloid plaques and intracellular neurofibrillary tangles. Recent studies suggest a relationship between the endocrinal dysregulation and the neuronal loss during the AD pathology. Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and hypothalamic-pituitary-gonadal (HPG) axis regulating circulating levels of glucocorticoid hormones has been implicated in the pathophysiology of AD. Likewise, dysregulated insulin signaling, impaired glucose uptake and insulin resistance are some of the prime factors in the onset/progression of AD. In this review, we have discussed the changes in HPA and HPG axes, implicated insulin resistance/signaling and glucose regulation during the onset/progression of AD. Therefore, simultaneous detection of these endocrinal markers in the early or presymptomatic stages may help in the early diagnosis of AD. This evidence for implicated endocrinal functions supports the fact that modulation of endocrinal pathways can be used as therapeutic targets for AD. Future studies need to determine how the induction or inhibition of endocrinal targets could be used for predictable neuroprotection in AD therapies.
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Affiliation(s)
- Mir Hilal Ahmad
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Mahino Fatima
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Amal Chandra Mondal
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India,
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13
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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 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] [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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14
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Panizzon MS, Hauger RL, Xian H, Jacobson K, Lyons MJ, Franz CE, Kremen WS. Interactive effects of testosterone and cortisol on hippocampal volume and episodic memory in middle-aged men. Psychoneuroendocrinology 2018; 91:115-122. [PMID: 29547742 PMCID: PMC5931212 DOI: 10.1016/j.psyneuen.2018.03.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/06/2018] [Accepted: 03/07/2018] [Indexed: 01/30/2023]
Abstract
Animal and human research suggests that testosterone is associated with hippocampal structure and function. Studies examining the association between testosterone and either hippocampal structure or hippocampal-mediated cognitive processes have overwhelmingly focused on the effects of testosterone alone, without considering the interaction of other neuroendocrine factors. The aim of the present study was to examine the interactive effects of testosterone and cortisol in relation to hippocampal volume and episodic memory in a sample of late-middle aged men from the Vietnam Era Twin Study of Aging. The average age of participants was 56.3 years (range 51-60). Salivary hormone samples were collected at multiple time-points on two non-consecutive at-home days, and an in-lab assessment. Area under the curve with respect to ground measures for cortisol and testosterone were utilized. Significant testosterone-by-cortisol interactions were observed for hippocampal volume, and episodic memory. When cortisol levels were elevated (1 SD above the mean), testosterone levels were positively associated with hippocampal volume and memory performance. However, when cortisol levels were low (1 SD below the mean), testosterone levels were inversely related to hippocampal volume and memory performance. These findings suggest that in context of high cortisol levels, testosterone may be neuroprotective. In contrast, low testosterone may also be neuroprotective in the context of low cortisol levels. To our knowledge this is the first demonstration of such an interaction in a structural brain measure and an associated cognitive ability. These results argue in favor of broadening neuroendocrine research to consider the simultaneous and interactive effects of multiple hormones on brain structure and function.
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Affiliation(s)
- Matthew S. Panizzon
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA,Correspondence: 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 L. Hauger
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA,Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, San Diego, CA
| | - Hong Xian
- Department of Biostatistics, St. Louis University, College for Public Health & Social Justice, St. Louis, MO,Research Service, St. Louis Veterans Affairs Medical Center, St. Louis, MO
| | | | - Michael J. Lyons
- Department of Psychological and Brain Sciences, Boston University, Boston, MA
| | - Carol E. Franz
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Center for Behavior Genetics of Aging, University of California, San Diego, La Jolla, CA
| | - William S. Kremen
- Department of Psychiatry, University of California, San Diego, La Jolla, CA,Center for Behavior Genetics of Aging, 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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15
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Asih PR, Tegg ML, Sohrabi H, Carruthers M, Gandy SE, Saad F, Verdile G, Ittner LM, Martins RN. Multiple Mechanisms Linking Type 2 Diabetes and Alzheimer's Disease: Testosterone as a Modifier. J Alzheimers Dis 2018; 59:445-466. [PMID: 28655134 DOI: 10.3233/jad-161259] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Evidence in support of links between type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has increased considerably in recent years. AD pathological hallmarks include the accumulation of extracellular amyloid-β (Aβ) and intracellular hyperphosphorylated tau in the brain, which are hypothesized to promote inflammation, oxidative stress, and neuronal loss. T2DM exhibits many AD pathological features, including reduced brain insulin uptake, lipid dysregulation, inflammation, oxidative stress, and depression; T2DM has also been shown to increase AD risk, and with increasing age, the prevalence of both conditions increases. In addition, amylin deposition in the pancreas is more common in AD than in normal aging, and although there is no significant increase in cerebral Aβ deposition in T2DM, the extent of Aβ accumulation in AD correlates with T2DM duration. Given these similarities and correlations, there may be common underlying mechanism(s) that predispose to both T2DM and AD. In other studies, an age-related gradual loss of testosterone and an increase in testosterone resistance has been shown in men; low testosterone levels can also occur in women. In this review, we focus on the evidence for low testosterone levels contributing to an increased risk of T2DM and AD, and the potential of testosterone treatment in reducing this risk in both men and women. However, such testosterone treatment may need to be long-term, and would need regular monitoring to maintain testosterone at physiological levels. It is possible that a combination of testosterone therapy together with a healthy lifestyle approach, including improved diet and exercise, may significantly reduce AD risk.
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Affiliation(s)
- Prita R Asih
- Department of Anatomy, Dementia Research Unit, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
| | - Michelle L Tegg
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia
| | - Hamid Sohrabi
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia.,Australian Alzheimer's Research Foundation Perth, WA, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia
| | | | - Samuel E Gandy
- Departments of Neurology and Psychiatry and the Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY, USA
| | - Farid Saad
- Bayer Pharma AG, Global Medical Affairs Andrology, Berlin, Germany.,Gulf Medical University School of Medicine, Ajman, UAE
| | - Giuseppe Verdile
- Australian Alzheimer's Research Foundation Perth, WA, Australia.,School of Biomedical Sciences, Curtin University of Technology, Bentley, WA, Australia
| | - Lars M Ittner
- Department of Anatomy, Dementia Research Unit, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,Neuroscience Research Australia, Sydney, NSW, Australia
| | - Ralph N Martins
- KaRa Institute of Neurological Diseases, Sydney, NSW, Australia.,School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia.,Australian Alzheimer's Research Foundation Perth, WA, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia
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16
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Bojar I, Stasiak M, Cyniak-Magierska A, Raczkiewicz D, Lewiński A. Cognitive Function, APOE Gene Polymorphisms, and Thyroid Status Associations in Postmenopausal Women in Poland. Dement Geriatr Cogn Disord 2018; 42:169-185. [PMID: 27649316 DOI: 10.1159/000449373] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/01/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The objective of the study was to analyze a potential association between cognitive functions and thyroid status in postmenopausal women with different polymorphisms of the apolipoprotein E gene (APOE). METHODS The examined population included 402 postmenopausal women from south-eastern Poland. The evaluation of cognitive functions was made with the use of the diagnostic Central Nervous System-Vital Signs equipment (Polish version). Multiplex polymerase chain reactions were performed to assess APOE polymorphisms. The thyroid hormone tests were assessed by an accredited laboratory. RESULTS AND CONCLUSION Lower results of cognitive functions were associated with the presence of the ε4 APOE allele in postmenopausal women. The ε4 APOE polymorphism was associated with a higher concentration of thyroid-stimulating hormone and lower concentrations of free triiodothyronine and total triiodothyronine.
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Affiliation(s)
- Iwona Bojar
- Department for Health Problems of Ageing, Institute of Rural Health, Lublin, Poland
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17
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Bojar I, Pinkas J, Gujski M, Owoc A, Raczkiewicz D, Gustaw-Rothenberg K. Postmenopausal cognitive changes and androgen levels in the context of apolipoprotein E polymorphism. Arch Med Sci 2017; 13:1148-1159. [PMID: 28883857 PMCID: PMC5575214 DOI: 10.5114/aoms.2016.62869] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/25/2016] [Indexed: 01/08/2023] Open
Abstract
INTRODUCTION The focus of this study was to assess cognitive functions in relation to androgens and specifically testosterone and dehydroepiandrosterone in postmenopausal women as well as the correlation between cognitive functions and these two androgens according to polymorphism of the apolipoprotein E gene (APOE). MATERIAL AND METHODS A group of 402 women was recruited to the study (minimum 2 years after the last menstruation, follicle-stimulating hormone (FSH) more than 30 U/ml and no dementia signs on Montreal Cognitive Assessment). The computerized battery of the Central Nervous System Vital Signs test was used to diagnose cognitive functions. APOE genotyping was performed by multiplex polymerase chain reaction (PCR). Testosterone (TTE) and dehydroepiandrosterone (DHEA) in the blood serum were assessed for further statistical correlations analysis. RESULTS In the group of postmenopausal women, higher testosterone concentration was associated with lower scores for Neurocognition Index (NCI) (p = 0.028), memory (p = 0.008) and psychomotor speed (p < 0.001). Presence of at least one APOE ε4 allele potentiated testosterone's negative influence on cognitive functions (p < 0.05). Woman with a high normal level of DHEA scored significantly better in verbal (p = 0.027) and visual memory (p < 0.001) than other participants. APOE polymorphism did not modify the relationship between DHEA concentration and scores for cognitive functions. CONCLUSIONS Hormonal balance variations after menopause may influence brain processes concerned with cognition, especially memory and psychomotor speed. The observed effects may be related to androgens' influence on higher cortical functions in the changed hormonal dynamics of the postmenopausal period.
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Affiliation(s)
- Iwona Bojar
- Department for Women Health, Institute of Rural Health, Lublin, Poland
| | - Jarosław Pinkas
- School of Public Health, Center of Postgraduate Medical Education, Warsaw, Poland
| | - Mariusz Gujski
- Department of Prevention of Environmental Hazards and Allergology, Medical University of Warsaw, Warsaw, Poland
| | - Alfred Owoc
- Center for Public Health and Health Promotion, Institute of Rural Health, Lublin, Poland
| | - Dorota Raczkiewicz
- Institute of Statistics and Demography, Warsaw School of Economics, Warsaw, Poland
| | - Kasia Gustaw-Rothenberg
- Lou Ruvo Brain Wellness Center, Neurological Institute, The Cleveland Clinic Foundation, Cleveland, OH, USA
- Department of Neurodegenerative Diseases, Institute of Rural Health, Lublin, Poland
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18
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Nead KT, Gaskin G, Chester C, Swisher-McClure S, Dudley JT, Leeper NJ, Shah NH. Influence of age on androgen deprivation therapy-associated Alzheimer's disease. Sci Rep 2016; 6:35695. [PMID: 27752112 PMCID: PMC5067668 DOI: 10.1038/srep35695] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/03/2016] [Indexed: 12/01/2022] Open
Abstract
We recently found an association between androgen deprivation therapy (ADT) and Alzheimer’s disease. As Alzheimer’s disease is a disease of advanced age, we hypothesize that older individuals on ADT may be at greatest risk. We conducted a retrospective multi-institutional analysis among 16,888 individuals with prostate cancer using an informatics approach. We tested the effect of ADT on Alzheimer’s disease using Kaplan–Meier age stratified analyses in a propensity score matched cohort. We found a lower cumulative probability of remaining Alzheimer’s disease-free between non-ADT users age ≥70 versus those age <70 years (p < 0.001) and between ADT versus non-ADT users ≥70 years (p = 0.034). The 5-year probability of developing Alzheimer’s disease was 2.9%, 1.9% and 0.5% among ADT users ≥70, non-ADT users ≥70 and individuals <70 years, respectively. Compared to younger individuals older men on ADT may have the greatest absolute Alzheimer’s disease risk. Future work should investigate the ADT Alzheimer’s disease association in advanced age populations given the greater potential clinical impact.
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Affiliation(s)
- Kevin T Nead
- Stanford Center for Biomedical Informatics Research, Stanford University, 1265 Welch Road, Stanford, California, 94305, USA.,Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania, 19104, USA
| | - Greg Gaskin
- Stanford Center for Biomedical Informatics Research, Stanford University, 1265 Welch Road, Stanford, California, 94305, USA
| | - Cariad Chester
- Stanford Center for Biomedical Informatics Research, Stanford University, 1265 Welch Road, Stanford, California, 94305, USA
| | - Samuel Swisher-McClure
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania, 19104, USA
| | - Joel T Dudley
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, 10029, USA
| | - Nicholas J Leeper
- Stanford Cardiovascular Institute, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California, 94305, USA
| | - Nigam H Shah
- Stanford Center for Biomedical Informatics Research, Stanford University, 1265 Welch Road, Stanford, California, 94305, USA
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19
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Uchoa MF, Moser VA, Pike CJ. Interactions between inflammation, sex steroids, and Alzheimer's disease risk factors. Front Neuroendocrinol 2016; 43:60-82. [PMID: 27651175 PMCID: PMC5123957 DOI: 10.1016/j.yfrne.2016.09.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/10/2016] [Accepted: 09/14/2016] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disorder for which there are no effective strategies to prevent or slow its progression. Because AD is multifactorial, recent research has focused on understanding interactions among the numerous risk factors and mechanisms underlying the disease. One mechanism through which several risk factors may be acting is inflammation. AD is characterized by chronic inflammation that is observed before clinical onset of dementia. Several genetic and environmental risk factors for AD increase inflammation, including apolipoprotein E4, obesity, and air pollution. Additionally, sex steroid hormones appear to contribute to AD risk, with age-related losses of estrogens in women and androgens in men associated with increased risk. Importantly, sex steroid hormones have anti-inflammatory actions and can interact with several other AD risk factors. This review examines the individual and interactive roles of inflammation and sex steroid hormones in AD, as well as their relationships with the AD risk factors apolipoprotein E4, obesity, and air pollution.
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Affiliation(s)
- Mariana F Uchoa
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - V Alexandra Moser
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Christian J Pike
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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20
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Mahmoud R, Wainwright SR, Galea LAM. Sex hormones and adult hippocampal neurogenesis: Regulation, implications, and potential mechanisms. Front Neuroendocrinol 2016; 41:129-52. [PMID: 26988999 DOI: 10.1016/j.yfrne.2016.03.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/12/2016] [Accepted: 03/14/2016] [Indexed: 11/16/2022]
Abstract
Neurogenesis within the adult hippocampus is modulated by endogenous and exogenous factors. Here, we review the role of sex hormones in the regulation of adult hippocampal neurogenesis in males and females. The review is framed around the potential functional implications of sex hormone regulation of adult hippocampal neurogenesis, with a focus on cognitive function and mood regulation, which may be related to sex differences in incidence and severity of dementia and depression. We present findings from preclinical studies of endogenous fluctuations in sex hormones relating to reproductive function and ageing, and from studies of exogenous hormone manipulations. In addition, we discuss the modulating roles of sex, age, and reproductive history on the relationship between sex hormones and neurogenesis. Because sex hormones have diverse targets in the central nervous system, we overview potential mechanisms through which sex hormones may influence hippocampal neurogenesis. Lastly, we advocate for a more systematic consideration of sex and sex hormones in studying the functional implications of adult hippocampal neurogenesis.
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Affiliation(s)
- Rand Mahmoud
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Steven R Wainwright
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
| | - Liisa A M Galea
- Department of Psychology, University of British Columbia, Vancouver, Canada; Centre for Brain Health, University of British Columbia, Vancouver, Canada.
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21
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Moser VA, Pike CJ. Obesity and sex interact in the regulation of Alzheimer's disease. Neurosci Biobehav Rev 2015; 67:102-18. [PMID: 26708713 DOI: 10.1016/j.neubiorev.2015.08.021] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/01/2015] [Accepted: 08/03/2015] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, for which a number of genetic, environmental, and lifestyle risk factors have been identified. A significant modifiable risk factor is obesity in mid-life. Interestingly, both obesity and AD exhibit sex differences and are regulated by sex steroid hormones. Accumulating evidence suggests interactions between obesity and sex in regulation of AD risk, although the pathways underlying this relationship are unclear. Inflammation and the E4 allele of apolipoprotein E have been identified as independent risk factors for AD and both interact with obesity and sex steroid hormones. We review the individual and cooperative effects of obesity and sex on development of AD and examine the potential contributions of apolipoprotein E, inflammation, and their interactions to this relationship.
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Affiliation(s)
- V Alexandra Moser
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA.
| | - Christian J Pike
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.
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22
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Development and aging of cortical thickness correspond to genetic organization patterns. Proc Natl Acad Sci U S A 2015; 112:15462-7. [PMID: 26575625 DOI: 10.1073/pnas.1508831112] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There is a growing realization that early life influences have lasting impact on brain function and structure. Recent research has demonstrated that genetic relationships in adults can be used to parcellate the cortex into regions of maximal shared genetic influence, and a major hypothesis is that genetically programmed neurodevelopmental events cause a lasting impact on the organization of the cerebral cortex observable decades later. Here we tested how developmental and lifespan changes in cortical thickness fit the underlying genetic organizational principles of cortical thickness in a longitudinal sample of 974 participants between 4.1 and 88.5 y of age with a total of 1,633 scans, including 773 scans from children below 12 y. Genetic clustering of cortical thickness was based on an independent dataset of 406 adult twins. Developmental and adult age-related changes in cortical thickness followed closely the genetic organization of the cerebral cortex, with change rates varying as a function of genetic similarity between regions. Cortical regions with overlapping genetic architecture showed correlated developmental and adult age change trajectories and vice versa for regions with low genetic overlap. Thus, effects of genes on regional variations in cortical thickness in middle age can be traced to regional differences in neurodevelopmental change rates and extrapolated to further adult aging-related cortical thinning. This finding suggests that genetic factors contribute to cortical changes through life and calls for a lifespan perspective in research aimed at identifying the genetic and environmental determinants of cortical development and aging.
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23
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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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24
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Lyall DM, Royle NA, Harris SE, Bastin ME, Maniega SM, Murray C, Lutz MW, Saunders AM, Roses AD, del Valdés Hernández MC, Starr JM, Porteous DJ, Wardlaw JM, Deary IJ. Alzheimer's disease susceptibility genes APOE and TOMM40, and hippocampal volumes in the Lothian birth cohort 1936. PLoS One 2013; 8:e80513. [PMID: 24260406 PMCID: PMC3829876 DOI: 10.1371/journal.pone.0080513] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 10/04/2013] [Indexed: 12/12/2022] Open
Abstract
The APOE ε and TOMM40 rs10524523 (‘523’) variable length poly-T repeat gene loci have been significantly and independently associated with Alzheimer’s disease (AD) related phenotypes such as age of clinical onset. Hippocampal atrophy has been significantly associated with memory impairment, a characteristic of AD. The current study aimed to test for independent effects of APOE ε and TOMM40 ‘523’ genotypes on hippocampal volumes as assessed by brain structural MRI in a relatively large sample of community-dwelling older adults. As part of a longitudinal study of cognitive ageing, participants in the Lothian Birth Cohort 1936 underwent genotyping for APOE ε2/ε3/ε4 status and TOMM40 ‘523’ poly-T repeat length, and detailed structural brain MRI at a mean age of 72.7 years (standard deviation = 0.7, N range = 624 to 636). No significant effects of APOE ε or TOMM40 523 genotype were found on hippocampal volumes when analysed raw, or when adjusted for either intracranial or total brain tissue volumes. In summary, in a large community-dwelling sample of older adults, we found no effects of APOE ε or TOMM40 523 genotypes on hippocampal volumes. This is discrepant with some previous reports of significant association between APOE and left/right hippocampal volumes, and instead echoes other reports that found no association. Previous significant findings may partly reflect type 1 error. Future studies should carefully consider: 1) their specific techniques in adjusting for brain size; 2) assessing more detailed sub-divisions of the hippocampal formation; and 3) testing whether significant APOE-hippocampal associations are independent of generalised brain atrophy.
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Affiliation(s)
- Donald M. Lyall
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Brain Research Imaging Centre, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom
- Medical Genetics Section, Centre for Genomics and Experimental Medicine and MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Natalie A. Royle
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Brain Research Imaging Centre, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Sarah E. Harris
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Medical Genetics Section, Centre for Genomics and Experimental Medicine and MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark E. Bastin
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Brain Research Imaging Centre, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Susana Muñoz Maniega
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Brain Research Imaging Centre, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Catherine Murray
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael W. Lutz
- Joseph & Kathleen Bryan Alzheimer’s Disease Research Center, Department of Neurology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Ann M. Saunders
- Joseph & Kathleen Bryan Alzheimer’s Disease Research Center, Department of Neurology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Allen D. Roses
- Joseph & Kathleen Bryan Alzheimer’s Disease Research Center, Department of Neurology, Duke University Medical Center, Durham, North Carolina, United States of America
- Zinfandel Pharmaceuticals, Inc., Durham, North Carolina, United States of America
| | - Maria C. del Valdés Hernández
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Brain Research Imaging Centre, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - John M. Starr
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - David. J. Porteous
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Medical Genetics Section, Centre for Genomics and Experimental Medicine and MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Joanna M. Wardlaw
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Brain Research Imaging Centre, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Collaboration, Division of Neuroimaging Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Ian J. Deary
- Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom
- Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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25
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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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26
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Kremen WS, Fennema-Notestine C, Eyler LT, Panizzon MS, Chen CH, Franz CE, Lyons MJ, Thompson WK, Dale AM. Genetics of brain structure: contributions from the Vietnam Era Twin Study of Aging. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:751-61. [PMID: 24132907 PMCID: PMC4754776 DOI: 10.1002/ajmg.b.32162] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 03/15/2013] [Indexed: 11/09/2022]
Abstract
Understanding the genetics of neuropsychiatric disorders requires an understanding of the genetics of brain structure and function. The Vietnam Era Twin Study of Aging (VETSA) is a longitudinal behavioral genetic study focused on cognitive and brain aging. Here, we describe basic science work carried out within the VETSA MRI study that provides meaningful contributions toward the study of neuropsychiatric disorders. VETSA produced the first comprehensive assessment of the heritability of cortical and subcortical brain structure sizes, all within the same individuals. We showed that neocortical thickness and surface area are largely genetically distinct. With continuous neocortical thickness maps, we demonstrated regional specificity of genetic influences, and that genetic factors did not conform to traditional regions of interest (ROIs). However, there was some evidence for different genetic factors accounting for different types of cortex, and for genetic relationships across cortical regions corresponding to anatomical and functional connectivity and brain maturation patterns. With continuous neocortical surface area maps, we confirmed the anterior-posterior gradient of genetic influences on cortical area patterning demonstrated in animal models. Finally, we used twin methods to create the first map of cortical ROIs based entirely on genetically informative data. We conclude that these genetically based cortical phenotypes may be more appropriate for genetic studies than traditional ROIs based on structure or function. Our results also suggest that cortical volume-the product of thickness and surface area-is a problematic phenotype for genetic studies because two independent sets of genes may be obscured. Examples supporting the validity of these conclusions are provided.
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Affiliation(s)
- William S. Kremen
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, California,Center of Excellence for Stress and Mental Health, VA San Diego Healthcare System, La Jolla, California,Correspondence to: William S. Kremen, Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093.,
| | - Christine Fennema-Notestine
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Department of Radiology, University of California, San Diego, La Jolla, California
| | - Lisa T. Eyler
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Mental Illness Research, Education, and Clinical Center, VA San Diego Healthcare System, La Jolla, California
| | - Matthew S. Panizzon
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, California
| | - Chi-Hua Chen
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, California
| | - Carol E. Franz
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, California
| | - Michael J. Lyons
- Department of Psychology, Boston University, Boston, Massachusetts
| | - Wesley K. Thompson
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Twin Research Laboratory, Center for Behavioral Genomics, University of California, San Diego, La Jolla, California
| | - Anders M. Dale
- Department of Psychiatry, University of California, San Diego, La Jolla, California,Department of Radiology, University of California, San Diego, La Jolla, California,Department of Neurosciences, University of California, San Diego, La Jolla, California
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27
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Abstract
The Vietnam Era Twin Study of Aging (VETSA) is a longitudinal behavioral genetic study with a primary focus on cognitive and brain aging in men. It comprises a subset of over 1,200 twins from the Vietnam Era Twin Registry. Like many other studies of aging, the VETSA includes many different phenotypes, but there are some key features that distinguish it from most other behavioral genetic aging studies. First, the initial assessment was conducted when all participants were middle-aged. Second, the age range of participants is narrow; all were in their 50s at the time of the initial recruitment. Third, the study includes an extensive and demanding neurocognitive test battery that was designed to provide good coverage of different cognitive abilities and avoid ceiling effects in middle-aged adults. Fourth, young adult cognitive test data (at an average age of 20 years) are available to provide a gauge of cognitive change. These features make the VETSA ideal for studying the heterogeneity of within-individual trajectories from midlife to old age, and for early detection of risk factors for cognitive decline.
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Affiliation(s)
- William S Kremen
- Department of Psychiatry, University of California, San Diego, CA, USA.
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28
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Fennema-Notestine C, Panizzon MS, Thompson WR, Chen CH, Eyler LT, Fischl B, Franz CE, Grant MD, Jak AJ, Jernigan TL, Lyons MJ, Neale MC, Seidman LJ, Tsuang MT, Xian H, Dale AM, Kremen WS. Presence of ApoE ε4 allele associated with thinner frontal cortex in middle age. J Alzheimers Dis 2012; 26 Suppl 3:49-60. [PMID: 21971450 DOI: 10.3233/jad-2011-0002] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The presence of an ApoE ε4 allele (ε4+) increases the risk of developing Alzheimer's disease (AD). Previous studies support an adverse relationship between ε4+ status and brain structure and function in mild cognitive impairment and AD; in contrast, the presence of an ε2 allele may be protective. Whether these findings reflect disease-related effects or pre-existing endophenotypes, however, remains unclear. The present study examined the influence of ApoE allele status on brain structure solely during middle-age in a large, national sample. Participants were 482 men, ages 51-59, from the Vietnam Era Twin Study of Aging (VETSA). T1-weighted images were used in volumetric segmentation and cortical surface reconstruction methods to measure regional volume and thickness. Primary linear mixed effects models predicted structural measures with ApoE status (ε3/3, ε2/3, ε3/4) and control variables for effects of site, non-independence of twin data, age, and average cranial vault or cortical thickness. Relative to the ε3/3 group, the ε3/4 group demonstrated significantly thinner cortex in superior frontal and left rostral and right caudal midfrontal regions; there were no significant effects of ε4 status on any temporal lobe measures. The ε2/3 group demonstrated significantly thicker right parahippocampal cortex relative to the ε3/3 group. The ApoE ε4 allele may influence cortical thickness in frontal areas, which are later developing regions thought to be more susceptible to the natural aging process. Previous conflicting findings for mesial temporal regions may be driven by the inclusion of older individuals, who may evidence preclinical manifestations of disease, and by unexamined moderators of ε4-related effects. The presence of the ε2 allele was related to thicker cortex, supporting a protective role. Ongoing follow-up of the VETSA sample may shed light on the potential for age- and disease-related mediation of the influence of ApoE allele status.
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29
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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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30
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Anand R, Kaushal A, Wani WY, Gill KD. Road to Alzheimer's disease: the pathomechanism underlying. Pathobiology 2011; 79:55-71. [PMID: 22205086 DOI: 10.1159/000332218] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 08/23/2011] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD), the most common cause of dementia, results from the interplay of various deregulated mechanisms triggering a complex pathophysiology. The neurons suffer from and slowly succumb to multiple irreversible damages, resulting in cell death and thus memory deficits that characterize AD. In spite of our vast knowledge, it is still unclear as to when the disease process starts and how long the perturbations continue before the disease manifests. Recent studies provide sufficient evidence to prove amyloid β (Aβ) as the primary cause initiating secondary events, but Aβ is also known to be produced under normal conditions and to possess physiological roles, hence, the questions that remain are: What are the factors that lead to abnormal Aβ production? When does Aβ turn into a pathological molecule? What is the chain of events that follows Aβ? The answers are still under debate, and further insight may help us in creating better diagnostic and therapeutic options in AD. The present article attempts to review the current literature regarding AD pathophysiology and proposes a pathophysiologic cascade in AD.
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Affiliation(s)
- R Anand
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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31
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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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33
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Vasilopoulos T, Kremen WS, Kim K, Panizzon MS, Stein PK, Xian H, Grant MD, Lyons MJ, Toomey R, Eaves LJ, Franz CE, Jacobson KC. Untreated hypertension decreases heritability of cognition in late middle age. Behav Genet 2011; 42:107-20. [PMID: 21688193 DOI: 10.1007/s10519-011-9479-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 06/01/2011] [Indexed: 10/18/2022]
Abstract
Hypertension is a risk factor for cognitive decline, but the mechanisms underlying the effects of hypertension on cognition, particularly in midlife, are unclear. We examined whether hypertension modifies genetic influences on individual differences in cognition. Nine cognitive domains and general cognitive ability were assessed in a sample of 1,237 male twins aged 51-60 who were divided into three blood pressure groups: non-hypertensive; medicated hypertensive; and unmedicated hypertensive. Heritability was significantly lower among unmedicated hypertensives compared to medicated hypertensives and non-hypertensives for visual-spatial ability (p = 0.013) and episodic memory (p = 0.004). There were no heritability differences between non-hypertensives and medicated hypertensives. In addition, there were no significant differences in mean level cognition across the three blood pressure groups. These results suggest that in middle-aged men, untreated hypertension suppresses normal genetic influences on individual differences in certain domains of cognition prior to the emergence of hypertension-related effects on cognitive performance. These results further suggest that antihypertensive medication may protect against or reverse this effect.
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Affiliation(s)
- Terrie Vasilopoulos
- Department of Psychiatry & Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, MC 3077, rm 603, Chicago, IL 60637, USA.
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