{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,2]],"date-time":"2025-08-02T19:23:20Z","timestamp":1754162600816,"version":"3.41.2"},"reference-count":51,"publisher":"BMJ","issue":"7","license":[{"start":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T00:00:00Z","timestamp":1753833600000},"content-version":"unspecified","delay-in-days":29,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Laboratory of Exercises Rehabilitation Science","award":["2023KFZX005 and 2025KYPT12"],"award-info":[{"award-number":["2023KFZX005 and 2025KYPT12"]}]},{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2025,7,1]]},"published-print":{"date-parts":[[2025,7]]},"abstract":"<jats:sec>\n                  <jats:title>Introduction<\/jats:title>\n                  <jats:p>Epidemiological evidence regarding the impact of elite athletic careers on cognitive trajectories remains contentious. Although consistent physical activity has been associated with long-term brain health, former elite athletes appear to represent a unique population. While past research has established a connection between sport-related concussions (SRCs) and later cognitive decline, less attention has been given to the cognitive function of former athletes who have not experienced SRCs. Therefore, well-structured cross-sectional studies accounting for established dementia risk factors are needed to compare mild cognitive impairment (MCI) prevalence between former elite athletes and the general population.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods and analysis<\/jats:title>\n                  <jats:p>This cross-sectional study will be conducted at Beijing Sport University (BSU) in Beijing, China. It is designed as a comparative study, aiming to recruit a sample of around 360 participants aged 65 and above. This sample will comprise 180 former elite athletes without a history of SRCs recruited via the BSU Retirement Welfare Office (the former athlete group), and 180 age-matched individuals from the communities in three districts in Beijing (the comparison group). Participants will complete a comprehensive questionnaire covering sociodemographic information, dementia-related risk factors, current physical activity levels and, for the former athlete group specifically, details of their athletic careers. MCI and instrumental activities of daily living will be assessed using the Montreal Cognitive Assessment, Memtrax continuous recognition test and Lawton Instrumental Activities of Daily Living (IADL) scale. The primary objective is to determine whether former elite athletes without a history of SRCs have a lower MCI prevalence than the general population. The secondary objective is to assess if these former elite athletes have a reduced prevalence of amnestic MCI and impairment in IADL compared with the general population. Additionally, the study aims to explore whether specific career-related characteristics of former athletes, such as the type of sport and contact exposure, are correlated with their cognitive function and IADL abilities in later life as a secondary exploratory component. The study will calculate the crude prevalence ratios (PRs) and adjusted prevalence ratios (aPRs) with 95% CIs using the modified Poisson regression model with robust error variance.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Ethics and dissemination<\/jats:title>\n                  <jats:p>Ethical approval was obtained from the Ethics Committee\/Internal Review Board of BSU (approval number: 2024042H). All procedures will adhere to the Helsinki Declaration. The study\u2019s findings will be provided to participants as deemed appropriate. The outcomes will be communicated through abstract presentations at national or international conferences\/academic seminars, as well as through publication in a peer-reviewed journal.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Trial registration number<\/jats:title>\n                  <jats:p>ChiCTR2400085800.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjopen-2025-104901","type":"journal-article","created":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T11:20:45Z","timestamp":1753874445000},"page":"e104901","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Prevalence of mild cognitive impairment among former elite athletes without a history of sport-related concussions compared to the general older population: a protocol for a cross-sectional study with exploratory subgroup analyses"],"prefix":"10.1136","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3126-0871","authenticated-orcid":false,"given":"Shuo","family":"Luan","sequence":"first","affiliation":[{"name":"School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haojie","family":"Li","sequence":"additional","affiliation":[{"name":"School of Sport Engineering, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qing","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiahui","family":"Cong","sequence":"additional","affiliation":[{"name":"School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hanzhi","family":"He","sequence":"additional","affiliation":[{"name":"School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiaying","family":"Xu","sequence":"additional","affiliation":[{"name":"School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jingjing","family":"Ren","sequence":"additional","affiliation":[{"name":"School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jinghua","family":"Qian","sequence":"additional","affiliation":[{"name":"School of Sports Medicine and Rehabilitation, Beijing Sport University, Beijing, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2025,7,30]]},"reference":[{"key":"2025073004202440000_15.7.e104901.1","doi-asserted-by":"publisher","DOI":"10.1002\/alz.12478"},{"key":"2025073004202440000_15.7.e104901.2","doi-asserted-by":"crossref","DOI":"10.3389\/fneur.2021.719849","article-title":"Diagnosis and Treatment for Mild Cognitive Impairment: A Systematic Review of Clinical Practice Guidelines and Consensus Statements","volume":"12","author":"Chen","year":"2021","journal-title":"Front Neurol"},{"key":"2025073004202440000_15.7.e104901.3","doi-asserted-by":"publisher","DOI":"10.1016\/S1474-4422(03)00262-X"},{"key":"2025073004202440000_15.7.e104901.4","doi-asserted-by":"crossref","DOI":"10.1186\/s13195-015-0099-0","article-title":"Mild cognitive impairment and deficits in instrumental activities of daily living: a systematic review","volume":"7","author":"Jekel","year":"2015","journal-title":"Alzheimers Res Ther"},{"key":"2025073004202440000_15.7.e104901.5","doi-asserted-by":"crossref","first-page":"e661","DOI":"10.1016\/S2468-2667(20)30185-7","article-title":"Prevalence, risk factors, and management of dementia and mild cognitive impairment in adults aged 60 years or older in China: a cross-sectional study","volume":"5","author":"Jia","year":"2020","journal-title":"Lancet Public Health"},{"key":"2025073004202440000_15.7.e104901.6","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0000000000001936"},{"key":"2025073004202440000_15.7.e104901.7","doi-asserted-by":"publisher","DOI":"10.7326\/M17-1528"},{"key":"2025073004202440000_15.7.e104901.8","doi-asserted-by":"publisher","DOI":"10.1136\/bjsports-2020-102955"},{"key":"2025073004202440000_15.7.e104901.9","doi-asserted-by":"publisher","DOI":"10.1007\/s40279-020-01379-5"},{"key":"2025073004202440000_15.7.e104901.10","doi-asserted-by":"crossref","DOI":"10.3389\/fspor.2023.1181808","article-title":"The (cognitive) future of motor control and learning","volume":"5","author":"Koester","year":"2023","journal-title":"Front Sports Act Living"},{"key":"2025073004202440000_15.7.e104901.11","doi-asserted-by":"crossref","DOI":"10.1038\/srep01154","article-title":"Professional athletes have extraordinary skills for rapidly learning complex and neutral dynamic visual scenes","volume":"3","author":"Faubert","year":"2013","journal-title":"Sci Rep"},{"key":"2025073004202440000_15.7.e104901.12","doi-asserted-by":"crossref","DOI":"10.1155\/2017\/3589271","article-title":"Lifestyle Modulators of Neuroplasticity: How Physical Activity, Mental Engagement, and Diet Promote Cognitive Health during Aging","volume":"2017","author":"Phillips","year":"2017","journal-title":"Neural Plast"},{"key":"2025073004202440000_15.7.e104901.13","doi-asserted-by":"publisher","DOI":"10.1016\/j.neubiorev.2021.09.003"},{"key":"2025073004202440000_15.7.e104901.14","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1093\/eurpub\/ckad084","article-title":"Physical activity during early life and the risk of all-cause mortality in midlife: findings from a birth cohort study","volume":"33","author":"Feter","year":"2023","journal-title":"Eur J Public Health"},{"key":"2025073004202440000_15.7.e104901.15","doi-asserted-by":"crossref","first-page":"1419","DOI":"10.1007\/s40279-021-01594-8","article-title":"Mental Health and Wellbeing of Retired Elite and Amateur Rugby Players and Non-contact Athletes and Associations with Sports-Related Concussion: The UK Rugby Health Project","volume":"52","author":"Hind","year":"2022","journal-title":"Sports Med"},{"key":"2025073004202440000_15.7.e104901.16","doi-asserted-by":"publisher","DOI":"10.1007\/s40279-017-0810-3"},{"key":"2025073004202440000_15.7.e104901.17","doi-asserted-by":"crossref","first-page":"E16","DOI":"10.1097\/HTR.0000000000000420","article-title":"An Exploratory Study of Mild Cognitive Impairment of Retired Professional Contact Sport Athletes","volume":"33","author":"Baker","year":"2018","journal-title":"J Head Trauma Rehabil"},{"key":"2025073004202440000_15.7.e104901.18","doi-asserted-by":"publisher","DOI":"10.1136\/jnnp-2022-329675"},{"key":"2025073004202440000_15.7.e104901.19","doi-asserted-by":"publisher","DOI":"10.1007\/s00296-014-3093-0"},{"key":"2025073004202440000_15.7.e104901.20","doi-asserted-by":"publisher","DOI":"10.1136\/bjsports-2023-106898"},{"key":"2025073004202440000_15.7.e104901.21","first-page":"33","article-title":"Association between Sensation-Seeking Behaviors and Concussion-Related Knowledge, Attitudes, Perceived Norms, and Care-Seeking Behaviors among Collegiate Student-Athletes","volume":"21","author":"Callahan","year":"2022","journal-title":"J Sports Sci Med"},{"key":"2025073004202440000_15.7.e104901.22","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2021-049918","article-title":"Association between dementia parental family history and mid-life modifiable risk factors for dementia: a cross-sectional study using propensity score matching within the Lifelines cohort","volume":"11","author":"Vrijsen","year":"2021","journal-title":"BMJ Open"},{"key":"2025073004202440000_15.7.e104901.23","doi-asserted-by":"publisher","DOI":"10.1016\/j.addbeh.2018.10.011"},{"key":"2025073004202440000_15.7.e104901.24","doi-asserted-by":"publisher","DOI":"10.11909\/j.issn.1671-5411.2019.03.014"},{"key":"2025073004202440000_15.7.e104901.25","doi-asserted-by":"publisher","DOI":"10.11909\/j.issn.1671-5411.2018.01.011"},{"key":"2025073004202440000_15.7.e104901.26","doi-asserted-by":"crossref","DOI":"10.1002\/dmrr.3158","article-title":"Standards of medical care for type 2 diabetes in China 2019","volume":"35","author":"Jia","year":"2019","journal-title":"Diabetes Metab Res Rev"},{"key":"2025073004202440000_15.7.e104901.27","first-page":"12","article-title":"[Clinical guidelines for prevention and treatment of type 2 diabetes mellitus in the elderly in China (2022 edition)]","volume":"61","year":"2022","journal-title":"Zhonghua Nei Ke Za Zhi"},{"key":"2025073004202440000_15.7.e104901.28","first-page":"221","article-title":"[Chinese guidelines for lipid management (2023)]","volume":"51","year":"2023","journal-title":"Zhonghua Xin Xue Guan Bing Za Zhi"},{"key":"2025073004202440000_15.7.e104901.29","doi-asserted-by":"crossref","DOI":"10.3390\/ijerph182312698","article-title":"The Dose-Response Relationships of Different Dimensions of Physical Activity with Daily Physical Function and Cognitive Function in Chinese Adults with Hypertension: A Cross-Sectional Study","volume":"18","author":"Ding","year":"2021","journal-title":"Int J Environ Res Public Health"},{"key":"2025073004202440000_15.7.e104901.30","doi-asserted-by":"crossref","DOI":"10.1186\/s12889-023-16625-4","article-title":"The role of physical activity on healthcare utilization in China","volume":"23","author":"Lei","year":"2023","journal-title":"BMC Public Health"},{"key":"2025073004202440000_15.7.e104901.31","doi-asserted-by":"crossref","DOI":"10.3390\/jcm11216514","article-title":"Effects of Physical Activity on Daily Physical Function in Chinese Middle-Aged and Older Adults: A Longitudinal Study from CHARLS","volume":"11","author":"Tian","year":"2022","journal-title":"J Clin Med"},{"key":"2025073004202440000_15.7.e104901.32","doi-asserted-by":"crossref","DOI":"10.3390\/nu14173596","article-title":"Alcohol Consumption and Mild Cognitive Impairment: A Mendelian Randomization Study from Rural China","volume":"14","author":"Cui","year":"2022","journal-title":"Nutrients"},{"key":"2025073004202440000_15.7.e104901.33","doi-asserted-by":"publisher","DOI":"10.1038\/s41591-023-02383-8"},{"key":"2025073004202440000_15.7.e104901.34","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1016\/S2213-8587(21)00045-0","article-title":"Epidemiology and determinants of obesity in China","volume":"9","author":"Pan","year":"2021","journal-title":"Lancet Diabetes Endocrinol"},{"key":"2025073004202440000_15.7.e104901.35","doi-asserted-by":"crossref","first-page":"1043","DOI":"10.1007\/s10654-021-00792-y","article-title":"Association between body mass index, its change and cognitive impairment among Chinese older adults: a community-based, 9-year prospective cohort study","volume":"36","author":"Wu","year":"2021","journal-title":"Eur J Epidemiol"},{"key":"2025073004202440000_15.7.e104901.36","doi-asserted-by":"publisher","DOI":"10.1016\/j.jad.2021.08.093"},{"key":"2025073004202440000_15.7.e104901.37","doi-asserted-by":"crossref","first-page":"309","DOI":"10.18632\/aging.102616","article-title":"Changes in sleep duration and 3-year risk of mild cognitive impairment in Chinese older adults","volume":"12","author":"Zhu","year":"2020","journal-title":"Aging (Albany NY)"},{"key":"2025073004202440000_15.7.e104901.38","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2023.24031","article-title":"Association of Unhealthy Lifestyle and Genetic Risk Factors With Mild Cognitive Impairment in Chinese Older Adults","volume":"6","author":"Duan","year":"2023","journal-title":"JAMA Netw Open"},{"key":"2025073004202440000_15.7.e104901.39","doi-asserted-by":"crossref","first-page":"1377","DOI":"10.1007\/s00421-019-04128-3","article-title":"Physiological comparison between non-athletes, endurance, power and team athletes","volume":"119","author":"Degens","year":"2019","journal-title":"Eur J Appl Physiol"},{"key":"2025073004202440000_15.7.e104901.40","doi-asserted-by":"publisher","DOI":"10.1136\/bjsports-2013-093347"},{"key":"2025073004202440000_15.7.e104901.41","doi-asserted-by":"publisher","DOI":"10.1542\/peds.2008-0080"},{"key":"2025073004202440000_15.7.e104901.42","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1080\/23279095.2019.1602530","article-title":"Comparative study of two Chinese versions of Montreal Cognitive Assessment for Screening of Mild Cognitive Impairment","volume":"28","author":"Huang","year":"2021","journal-title":"Appl Neuropsychol Adult"},{"key":"2025073004202440000_15.7.e104901.43","doi-asserted-by":"publisher","DOI":"10.1016\/j.archger.2012.05.008"},{"key":"2025073004202440000_15.7.e104901.44","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1111\/cns.12391","article-title":"Neuropsychological and neuroimaging characteristics of amnestic mild cognitive impairment subtypes: a selective overview","volume":"21","author":"Li","year":"2015","journal-title":"CNS Neurosci Ther"},{"key":"2025073004202440000_15.7.e104901.45","doi-asserted-by":"crossref","first-page":"385","DOI":"10.3233\/JAD-190167","article-title":"A Computerized Continuous-Recognition Task for Measurement of Episodic Memory","volume":"69","author":"Ashford","year":"2019","journal-title":"JAD"},{"key":"2025073004202440000_15.7.e104901.46","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1002\/alz.13430","article-title":"Toward digitally screening and profiling AD: A GAMLSS approach of MemTrax in China","volume":"20","author":"Liu","year":"2024","journal-title":"Alzheimers Dement"},{"key":"2025073004202440000_15.7.e104901.47","doi-asserted-by":"crossref","first-page":"1257","DOI":"10.3233\/JAD-200936","article-title":"Validity of the MemTrax Memory Test Compared to the Montreal Cognitive Assessment in the Detection of Mild Cognitive Impairment and Dementia due to Alzheimer\u2019s Disease in a Chinese Cohort","volume":"80","author":"Liu","year":"2021","journal-title":"Journal of Alzheimer\u2019s Disease"},{"key":"2025073004202440000_15.7.e104901.48","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1097\/01.NAJ.0000314810.46029.74","article-title":"The Lawton instrumental activities of daily living scale","volume":"108","author":"Graf","year":"2008","journal-title":"Am J Nurs"},{"key":"2025073004202440000_15.7.e104901.49","first-page":"132","article-title":"The Validation of the Hong Kong Chinese Version of the Lawton Instrumental Activities of Daily Living Scale for Institutionalized Elderly Persons","volume":"22","author":"Tong","year":"2002","journal-title":"OTJR: Occupational Therapy Journal of Research"},{"key":"2025073004202440000_15.7.e104901.50","doi-asserted-by":"crossref","DOI":"10.1186\/s40798-015-0024-x","article-title":"Do Elite Athletes Live Longer? A Systematic Review of Mortality and Longevity in Elite Athletes","volume":"1","author":"Lemez","year":"2015","journal-title":"Sports Med Open"},{"key":"2025073004202440000_15.7.e104901.51","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1016\/j.jshs.2018.08.006","article-title":"Former athletes\u2019 lifestyle and self-definition changes after retirement from sports","volume":"9","author":"Yao","year":"2020","journal-title":"J Sport Health Sci"}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2025-104901","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T11:20:50Z","timestamp":1753874450000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2025-104901"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,7]]},"references-count":51,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,7,30]]},"published-print":{"date-parts":[[2025,7]]}},"alternative-id":["10.1136\/bmjopen-2025-104901"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2025-104901","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"type":"print","value":"2044-6055"},{"type":"electronic","value":"2044-6055"}],"subject":[],"published":{"date-parts":[[2025,7]]}}}