{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,3]],"date-time":"2026-11-03T12:38:24Z","timestamp":1793709504075,"version":"4.6.1"},"reference-count":31,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2022,9,10]],"date-time":"2022-09-10T00:00:00Z","timestamp":1662768000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2022,9,10]],"date-time":"2022-09-10T00:00:00Z","timestamp":1662768000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Neurol"],"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Background<\/jats:title>\n                <jats:p>Parkinson\u2019s disease (PD) is a progressive neurodegenerative disorder that causes motor symptoms and autonomic dysfunction. However, autonomic function tests commonly performed in PD can only evaluate either the sympathetic or parasympathetic nervous system. Therefore, the purpose of this pilot study is to investigate whether power spectral analysis of heart rate variability could detect both sympathetic and parasympathetic nervous dysfunctions in patients with PD.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Methods<\/jats:title>\n                <jats:p>Seventeen patients with PD and 11 healthy control subjects underwent electrocardiogram recording for the spectral analysis of heart rate variability to obtain values of low-frequency (LF) (0.04\u20130.15\u00a0Hz) and high-frequency (HF) (0.15\u20130.4\u00a0Hz) powers. Moreover, we examined the coefficient of variation of R\u2013R intervals (CVRR) as a parameter of parasympathetic function in all participants and performed <jats:sup>123<\/jats:sup>I-metaiodobenzylguanidine scintigraphy to measure the heart-to-mediastinum ratio as a parameter of cardiac sympathetic innervation in patients with PD.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>The median age of control subjects and PD patients was 63 and 66\u00a0years old, respectively. The median Hoehn and Yahr scale of PD patients was stage 2. The values of resting LF and HF powers widely varied. The median values of resting LF powers of control subjects and PD patients and those of HF powers were 169 and 70 ms<jats:sup>2<\/jats:sup>, 279 and 65 ms<jats:sup>2<\/jats:sup>, respectively, the difference was statistically insignificant. Approximately 41% of patients with PD had values below the first quartile of resting LF powers (&lt;\u200958 ms<jats:sup>2<\/jats:sup>) or HF powers (&lt;\u200950 ms<jats:sup>2<\/jats:sup>); however, no control subject had such low values. Positive correlations were found between resting LF powers and heart-to-mediastinum ratios of <jats:sup>123<\/jats:sup>I-metaiodobenzylguanidine uptake (<jats:italic>r<\/jats:italic>\u2009=\u20090.6) and between resting HF powers and CVRRs (<jats:italic>r<\/jats:italic>\u2009=\u20090.7). The resting LF power was also associated with CVRRs and constipation. Furthermore, a positive correlation was observed between resting LF powers and resting HF powers in patients with PD (<jats:italic>r<\/jats:italic>\u2009=\u20090.8).<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>The power spectral analysis of heart rate variability may be useful as a screening tool for detecting autonomic dysfunctions by detecting low resting LF and HF powers in patients with PD. Sympathetic and parasympathetic nerves may be concurrently damaged in patients with PD.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1186\/s12883-022-02872-2","type":"journal-article","created":{"date-parts":[[2022,9,10]],"date-time":"2022-09-10T06:06:28Z","timestamp":1662789988000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Power spectral analysis of heart rate variability is useful as a screening tool for detecting sympathetic and parasympathetic nervous dysfunctions in Parkinson\u2019s disease"],"prefix":"10.1186","volume":"22","author":[{"given":"Tomo","family":"Miyagi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masanobu","family":"Yamazato","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takuto","family":"Nakamura","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takashi","family":"Tokashiki","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yukihiro","family":"Namihira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kazuhito","family":"Kokuba","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Satoshi","family":"Ishihara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hirokuni","family":"Sakima","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yusuke","family":"Ohya","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2022,9,10]]},"reference":[{"key":"2872_CR1","doi-asserted-by":"publisher","first-page":"399","DOI":"10.1002\/mds.23462","volume":"26","author":"P Martinez-Martin","year":"2011","unstructured":"Martinez-Martin P, Rodriguez-Blazquez C, Kurtis MM, Chaudhuri KR, NMSS Validation Group. The impact of non-motor symptoms on health-related quality of life of patients with Parkinson\u2019s disease. Mov Disord. 2011;26:399\u2013406. https:\/\/doi.org\/10.1002\/mds.23462.","journal-title":"Mov Disord"},{"key":"2872_CR2","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1016\/s0197-4580(02)00065-9","volume":"24","author":"H Braak","year":"2003","unstructured":"Braak H, Del Tredici K, R\u00fcb U, de Vos RA, Jansen Steur EN, Braak E. Staging of brain pathology related to sporadic Parkinson\u2019s disease. Neurobiol Aging. 2003;24:197\u2013211. https:\/\/doi.org\/10.1016\/s0197-4580(02)00065-9.","journal-title":"Neurobiol Aging"},{"key":"2872_CR3","doi-asserted-by":"publisher","first-page":"284","DOI":"10.1111\/j.1365-2990.2006.00727.x","volume":"32","author":"A Bloch","year":"2006","unstructured":"Bloch A, Probst A, Bissig H, Adams H, Tolnay M. \u03b1-synuclein pathology of the spinal and peripheral autonomic nervous system in neurologically unimpaired elderly subjects. Neuropathol Appl Neurobiol. 2006;32:284\u201395. https:\/\/doi.org\/10.1111\/j.1365-2990.2006.00727.x.","journal-title":"Neuropathol Appl Neurobiol"},{"issue":"Suppl 2","key":"2872_CR4","doi-asserted-by":"publisher","first-page":"2","DOI":"10.1159\/000113469","volume":"38","author":"K Wakabayashi","year":"1997","unstructured":"Wakabayashi K, Takahashi H. Neuropathology of autonomic nervous system in Parkinson\u2019s disease. Eur Neurol. 1997;38(Suppl 2):2\u20137. https:\/\/doi.org\/10.1159\/000113469.","journal-title":"Eur Neurol"},{"key":"2872_CR5","doi-asserted-by":"publisher","first-page":"121","DOI":"10.1111\/bpa.12168","volume":"25","author":"K Seidel","year":"2015","unstructured":"Seidel K, Mahlke J, Siswanto S, Kr\u00fcger R, Heinsen H, Auburger G, Bouzrou M, Grinberg LT, Wicht H, Korf HW, den Dunnen W, R\u00fcb U. The brainstem pathologies of Parkinson\u2019s disease and dementia with Lewy bodies. Brain Pathol. 2015;25:121\u201335. https:\/\/doi.org\/10.1111\/bpa.12168.","journal-title":"Brain Pathol"},{"key":"2872_CR6","doi-asserted-by":"publisher","first-page":"890","DOI":"10.1002\/mds.10461","volume":"18","author":"F Courbon","year":"2003","unstructured":"Courbon F, Brefel-Courbon C, Thalamas C, Alibelli MJ, Berry I, Montastruc JL, Rascol O, Senard JM. Cardiac MIBG scintigraphy is a sensitive tool for detecting cardiac sympathetic denervation in Parkinson\u2019s disease. Mov Disord. 2003;18:890\u20137. https:\/\/doi.org\/10.1002\/mds.10461.","journal-title":"Mov Disord"},{"key":"2872_CR7","first-page":"71","volume":"41","author":"H Takatsu","year":"2000","unstructured":"Takatsu H, Nishida H, Matsuo H, Watanabe S, Nagashima K, Wada H, Noda T, Nishigaki K, Fujiwara H. Cardiac sympathetic denervation from the early stage of Parkinson\u2019s disease: clinical and experimental studies with radiolabeled MIBG. J Nucl Med. 2000;41:71\u20137.","journal-title":"J Nucl Med"},{"key":"2872_CR8","doi-asserted-by":"publisher","first-page":"1591","DOI":"10.1002\/mds.26424","volume":"30","author":"RB Postuma","year":"2015","unstructured":"Postuma RB, Berg D, Stern M, Poewe W, Olanow CW, Oertel W, Obeso J, Marek K, Litvan I, Lang AE, Halliday G, Goetz CG, Gasser T, Dubois B, Chan P, Bloem BR, Adler CH, Deuschl G. MDS clinical diagnostic criteria for Parkinson\u2019s disease. Mov Disord. 2015;30:1591\u2013601. https:\/\/doi.org\/10.1002\/mds.26424.","journal-title":"Mov Disord"},{"key":"2872_CR9","doi-asserted-by":"publisher","first-page":"190","DOI":"10.1007\/BF00252626","volume":"20","author":"T Dyrberg","year":"1981","unstructured":"Dyrberg T, Benn J, Christiansen JS, Hilsted J, Nerup J. Prevalence of diabetic autonomic neuropathy measured by simple bedside tests. Diabetologia. 1981;20:190\u20134. https:\/\/doi.org\/10.1007\/BF00252626.","journal-title":"Diabetologia"},{"key":"2872_CR10","doi-asserted-by":"publisher","first-page":"584","DOI":"10.1136\/bmj.4.5892.584","volume":"4","author":"T Wheeler","year":"1973","unstructured":"Wheeler T, Watkins PJ. Cardiac denervation in diabetes. Br Med J. 1973;4:584\u20136. https:\/\/doi.org\/10.1136\/bmj.4.5892.584.","journal-title":"Br Med J"},{"key":"2872_CR11","doi-asserted-by":"publisher","first-page":"1031","DOI":"10.1007\/s11517-006-0119-0","volume":"44","author":"U Rajendra Acharya","year":"2006","unstructured":"Rajendra Acharya U, Paul Joseph K, Kannathal N, Lim CM, Suri JS. Heart rate variability: a review. Med Biol Eng Comput. 2006;44:1031\u201351. https:\/\/doi.org\/10.1007\/s11517-006-0119-0.","journal-title":"Med Biol Eng Comput"},{"key":"2872_CR12","doi-asserted-by":"publisher","first-page":"1441","DOI":"10.1161\/01.cir.95.6.1441","volume":"95","author":"M Pagani","year":"1997","unstructured":"Pagani M, Montano N, Porta A, Malliani A, Abboud FM, Birkett C, Somers VK. Relationship between spectral components of cardiovascular variabilities and direct measures of muscle sympathetic nerve activity in humans. Circulation. 1997;95:1441\u20138. https:\/\/doi.org\/10.1161\/01.cir.95.6.1441.","journal-title":"Circulation"},{"key":"2872_CR13","doi-asserted-by":"publisher","first-page":"354","DOI":"10.1093\/oxfordjournals.eurheartj.a014868","volume":"17","author":"Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology","year":"1996","unstructured":"Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Eur Heart J. 1996;17:354\u201381. https:\/\/doi.org\/10.1093\/oxfordjournals.eurheartj.a014868.","journal-title":"Eur Heart J"},{"key":"2872_CR14","doi-asserted-by":"publisher","first-page":"1449","DOI":"10.1161\/01.cir.95.6.1449","volume":"95","author":"P van de Borne","year":"1997","unstructured":"van de Borne P, Montano N, Pagani M, Oren R, Somers VK. Absence of low-frequency variability of sympathetic nerve activity in severe heart failure. Circulation. 1997;95:1449\u201354. https:\/\/doi.org\/10.1161\/01.cir.95.6.1449.","journal-title":"Circulation"},{"key":"2872_CR15","doi-asserted-by":"publisher","first-page":"291","DOI":"10.1177\/147323000603400308","volume":"34","author":"H Kudat","year":"2006","unstructured":"Kudat H, Akkaya V, Sozen AB, Salman S, Demirel S, Ozcan M, Atilgan D, Yilmaz MT, Guven O. Heart rate variability in diabetes patients. J Int Med Res. 2006;34:291\u20136. https:\/\/doi.org\/10.1177\/147323000603400308.","journal-title":"J Int Med Res"},{"key":"2872_CR16","doi-asserted-by":"publisher","first-page":"117","DOI":"10.1007\/BF01845775","volume":"4","author":"D Claus","year":"1994","unstructured":"Claus D, Feistel H, Brunh\u00f6lzl C, Platsch G, Neund\u00f6rfer B, Wolf F. Investigation of parasympathetic and sympathetic cardiac innervation in diabetic neuropathy: heart rate variation versus meta-iodo-benzylguanidine measured by single photon emission computed tomography. Clin Auton Res. 1994;4:117\u201323. https:\/\/doi.org\/10.1007\/BF01845775.","journal-title":"Clin Auton Res"},{"issue":"Supplement","key":"2872_CR17","doi-asserted-by":"publisher","first-page":"479","DOI":"10.1620\/tjem.141.suppl_479","volume":"141","author":"S Kageyama","year":"1983","unstructured":"Kageyama S, Taniguchi I, Tanaka S, Tajima N, Saito N, Ikeda Y, Abe M. A critical level of diabetic autonomic neuropathy. Tohoku J Exp Med. 1983;141(Supplement):479\u201383. https:\/\/doi.org\/10.1620\/tjem.141.suppl_479.","journal-title":"Tohoku J Exp Med"},{"key":"2872_CR18","doi-asserted-by":"publisher","first-page":"515","DOI":"10.1016\/s1071-3581(97)90010-6","volume":"4","author":"C Kurata","year":"1997","unstructured":"Kurata C, Shouda S, Mikami T, Wakabayashi Y, Nakano T, Sugiyama T, Tawarahara K, Sakata K. Comparison of [123I] metaiodobenzylguanidine kinetics with heart rate variability and plasma norepinephrine level. J Nucl Cardiol. 1997;4:515\u201323. https:\/\/doi.org\/10.1016\/s1071-3581(97)90010-6.","journal-title":"J Nucl Cardiol"},{"key":"2872_CR19","doi-asserted-by":"publisher","first-page":"134","DOI":"10.1016\/j.parkreldis.2008.04.031","volume":"15","author":"CA Haensch","year":"2009","unstructured":"Haensch CA, Lerch H, J\u00f6rg J, Isenmann S. Cardiac denervation occurs independent of orthostatic hypotension and impaired heart rate variability in Parkinson\u2019s disease. Parkinsonism Relat Disord. 2009;15:134\u20137. https:\/\/doi.org\/10.1016\/j.parkreldis.2008.04.031.","journal-title":"Parkinsonism Relat Disord"},{"key":"2872_CR20","doi-asserted-by":"publisher","unstructured":"Katagiri A, Asahina M, Araki N, Poudel A, Fujinuma Y, Yamanaka Y, Kuwabara S. Myocardial 123I-MIBG uptake and cardiovascular autonomic function in Parkinson\u2019s disease. Parkinsons Dis. 2015; 805351. https:\/\/doi.org\/10.1155\/2015\/805351.","DOI":"10.1155\/2015\/805351"},{"issue":"Suppl 1","key":"2872_CR21","doi-asserted-by":"publisher","first-page":"146","DOI":"10.1080\/13506129.2019.1582505","volume":"26","author":"K Nakahara","year":"2019","unstructured":"Nakahara K, Nakane S, Ando Y. Correlation of heart rate variability analysis and MIBG myocardial scintigraphy in patients with Parkinson\u2019 s disease. Amyloid. 2019;26(Suppl 1):146\u20137. https:\/\/doi.org\/10.1080\/13506129.2019.1582505.","journal-title":"Amyloid"},{"key":"2872_CR22","doi-asserted-by":"publisher","first-page":"333","DOI":"10.1007\/s00415-016-8348-0","volume":"264","author":"M Suzuki","year":"2017","unstructured":"Suzuki M, Nakamura T, Hirayama M, Ueda M, Katsuno M, Sobue G. Cardiac parasympathetic dysfunction in the early phase of Parkinson\u2019s disease. J Neurol. 2017;264:333\u201340. https:\/\/doi.org\/10.1007\/s00415-016-8348-0.","journal-title":"J Neurol"},{"key":"2872_CR23","doi-asserted-by":"publisher","first-page":"79","DOI":"10.1016\/j.jns.2008.09.005","volume":"276","author":"M Shibata","year":"2009","unstructured":"Shibata M, Morita Y, Shimizu T, Takahashi K, Suzuki N. Cardiac parasympathetic dysfunction concurrent with cardiac sympathetic denervation in Parkinson\u2019s disease. J Neurol Sci. 2009;276:79\u201383. https:\/\/doi.org\/10.1016\/j.jns.2008.09.005.","journal-title":"J Neurol Sci"},{"key":"2872_CR24","doi-asserted-by":"publisher","first-page":"447","DOI":"10.1007\/BF01276420","volume":"103","author":"M Rodr\u00edguez","year":"1996","unstructured":"Rodr\u00edguez M, Sabat\u00e9 M, Troncoso E. Time and frequency domain analysis for the assessment of heart autonomic control in Parkinson\u2019s disease. J Neural Transm (Vienna). 1996;103:447\u201354. https:\/\/doi.org\/10.1007\/BF01276420.","journal-title":"J Neural Transm (Vienna)"},{"key":"2872_CR25","doi-asserted-by":"publisher","first-page":"667","DOI":"10.1046\/j.1468-1331.2000.00127.x","volume":"7","author":"M Kallio","year":"2000","unstructured":"Kallio M, Haapaniemi T, Turkka J, Suominen K, Tolonen U, Sotaniemi K, Heikkil\u00e4 VP, Myllyl\u00e4 V. Heart rate variability in patients with untreated Parkinson\u2019s disease. Eur J Neurol. 2000;7:667\u201372. https:\/\/doi.org\/10.1046\/j.1468-1331.2000.00127.x.","journal-title":"Eur J Neurol"},{"key":"2872_CR26","doi-asserted-by":"publisher","first-page":"959","DOI":"10.3390\/brainsci11080959","volume":"11","author":"KG Heimrich","year":"2021","unstructured":"Heimrich KG, Leshmann T, Schlattmann P, Prell T. Heart rate variability analysis in Parkinson\u2019s disease: a systematic review and meta-analysis. Brain Sci. 2021;11:959. https:\/\/doi.org\/10.3390\/brainsci11080959.","journal-title":"Brain Sci"},{"key":"2872_CR27","doi-asserted-by":"publisher","first-page":"1269","DOI":"10.1212\/wnl.52.6.1269","volume":"52","author":"K Iwanaga","year":"1999","unstructured":"Iwanaga K, Wakabayashi K, Yoshimoto M, Tomita I, Satoh H, Takashima H, Satoh A, Seto M, Tsujihata M, Takahashi H. Lewy body-type degeneration in cardiac plexus in Parkinson\u2019s and incidental Lewy body diseases. Neurology. 1999;52:1269\u201371. https:\/\/doi.org\/10.1212\/wnl.52.6.1269.","journal-title":"Neurology"},{"key":"2872_CR28","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1007\/s10286-021-00771-z","volume":"31","author":"KR Chaudhuri","year":"2021","unstructured":"Chaudhuri KR. Thirty years of research on autonomic dysfunction, non-motor features, and endophenotypes in Parkinson disease. Clin Auton Res. 2021;31:31\u20139. https:\/\/doi.org\/10.1007\/s10286-021-00771-z.","journal-title":"Clin Auton Res"},{"key":"2872_CR29","doi-asserted-by":"publisher","first-page":"229","DOI":"10.1002\/mds.26077","volume":"30","author":"C Pont-Sunyer","year":"2015","unstructured":"Pont-Sunyer C, Hptter A, Gaig C, Seppi K, Compta Y, Katzenschlager R, Mas N, Hofeneder D, Br\u00fccke T, Bay\u00e9s A, Wenzel K, Infante J, Zach H, Pirker W, Posada IJ, \u00c1lvarez R, Ispierto L, De F\u00e0bregues O, Call\u00e9n A, Palas\u00ed A, Aguilar M, Jos\u00e9 Mart\u00ed M, Valldeoriola F, Salamero M, Poewe W, Tolosa E. The onset of nonmotor symptoms in Parkinson\u2019s disease (The ONSET PD Study). Mov Disord. 2015;30:229\u201337. https:\/\/doi.org\/10.1002\/mds.26077.","journal-title":"Mov Disord"},{"key":"2872_CR30","doi-asserted-by":"publisher","first-page":"945","DOI":"10.1136\/jnnp-2015-310327","volume":"86","author":"K Tsujikawa","year":"2015","unstructured":"Tsujikawa K, Hasegawa Y, Yokoi S, Yasui K, Nanbu I, Yanagi T, Takahashi A. Chrolonogical changes of 123I-MIBG myocardial scintigraphy and clinical features of Parkinson\u2019s disease. J Neurol Neurosurg Psychiatry. 2015;86:945\u201351.","journal-title":"J Neurol Neurosurg Psychiatry"},{"key":"2872_CR31","doi-asserted-by":"publisher","first-page":"303","DOI":"10.1016\/j.parkreldis.2013.12.001","volume":"20","author":"JB Kim","year":"2014","unstructured":"Kim JB, Kim B-J, Koh S-B, Park K-W. Autonomic dysfunction according to disease progression in Parkinson\u2019s disease. Parkinsonism Relat Disord. 2014;20:303\u20137. https:\/\/doi.org\/10.1016\/j.parkreldis.2013.12.001.","journal-title":"Parkinsonism Relat Disord"}],"container-title":["BMC Neurology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12883-022-02872-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s12883-022-02872-2\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12883-022-02872-2.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,9,10]],"date-time":"2022-09-10T06:08:05Z","timestamp":1662790085000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmcneurol.biomedcentral.com\/articles\/10.1186\/s12883-022-02872-2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,9,10]]},"references-count":31,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["2872"],"URL":"https:\/\/doi.org\/10.1186\/s12883-022-02872-2","relation":{},"ISSN":["1471-2377"],"issn-type":[{"value":"1471-2377","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,9,10]]},"assertion":[{"value":"27 April 2022","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"2 September 2022","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"10 September 2022","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"This study was approved by the Ethics Committee of the University of the Ryukyus (#710) and conducted in accordance with the ethical standards in the 1964 Declaration of Helsinki and its later amendments. Written informed consent was obtained from all participants.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare that they have no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"339"}}