{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,1]],"date-time":"2026-03-01T02:56:17Z","timestamp":1772333777760,"version":"3.50.1"},"reference-count":26,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2017,3,30]],"date-time":"2017-03-30T00:00:00Z","timestamp":1490832000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The Ministry of Science and Technology, Taiwan","award":["MOST 104-2221-E-259-014"],"award-info":[{"award-number":["MOST 104-2221-E-259-014"]}]},{"name":"The Ministry of Science and Technology, Taiwan","award":["MOST 105-2221-E259-007"],"award-info":[{"award-number":["MOST 105-2221-E259-007"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Multiscale cross-approximate entropy (MC-ApEn) between two different physiological signals could evaluate cardiovascular health in diabetes. Whether MC-ApEn analysis between two similar signals such as photoplethysmographic (PPG) pulse amplitudes of bilateral fingertips can reflect diabetes status is unknown. From a middle-to-old-aged population free of prior cardiovascular disease, we selected the unaffected (no type 2 diabetes, n = 36), the well-controlled diabetes (glycated hemoglobin (HbA1c) &lt; 8%, n = 30), and the poorly- controlled diabetes (HbA1c \u2265 8%, n = 26) groups. MC-ApEn indexes were calculated from simultaneous consecutive 1500 PPG pulse amplitudes signals of bilateral index fingertips. The average of scale factors 1\u20135 (MC-ApEnSS) and of scale factors 6\u201310 (MC-ApEnLS) were defined as the small- and large-scales MC-ApEn, respectively. The MC-ApEnLS index was highest in the unaffected, followed by the well-controlled diabetes, and then the poorly-controlled diabetes (0.70, 0.62, and 0.53; all paired p-values were &lt;0.05); in contrast, the MC-ApEnSS index did not differ between groups. Our findings suggested that the bilateral fingertips large-scale MC-ApEnLS index of PPG pulse amplitudes might be able to evaluate the glycemic status and detect subtle vascular disease in type 2 diabetes.<\/jats:p>","DOI":"10.3390\/e19040145","type":"journal-article","created":{"date-parts":[[2017,3,30]],"date-time":"2017-03-30T09:49:54Z","timestamp":1490867394000},"page":"145","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Multiscale Cross-Approximate Entropy Analysis of Bilateral Fingertips Photoplethysmographic Pulse Amplitudes among Middle-to-Old Aged Individuals with or without Type 2 Diabetes"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2581-9384","authenticated-orcid":false,"given":"Hsien-Tsai","family":"Wu","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, National Dong-Hwa University, Hualien 97401, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cheng-Chan","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, National Dong-Hwa University, Hualien 97401, Taiwan"},{"name":"Department of Traditional Chinese Medicine, Buddhist Tzu-Chi General Hospital, Hualien 970, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gen-Min","family":"Lin","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, National Dong-Hwa University, Hualien 97401, Taiwan"},{"name":"Departments of Medicine, Hualien Armed Forces General Hospital, Hualien 970, Taiwan"},{"name":"Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bagus","family":"Haryadi","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, National Dong-Hwa University, Hualien 97401, Taiwan"},{"name":"Department of Physics, Universitas Ahmad Dahlan, Yogyakarta 55164, Indonesia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shiao-Chiang","family":"Chu","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, National Dong-Hwa University, Hualien 97401, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chieh-Ming","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, National Dong-Hwa University, Hualien 97401, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2524-9684","authenticated-orcid":false,"given":"Cheuk-Kwan","family":"Sun","sequence":"additional","affiliation":[{"name":"Department of Emergency Medicine, E-Da Hospital, I-Shou University, Kaohsiung 840, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,3,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2434","DOI":"10.1161\/01.CIR.99.18.2434","article-title":"Impact of aortic stiffness on survival in end-stage renal disease","volume":"99","author":"Blacher","year":"1999","journal-title":"Circulation"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2277","DOI":"10.1097\/00004872-200412000-00009","article-title":"Patient characteristics and factors associated with inter-arm difference of blood pressure measurements in a general population in Ohasama, Japan","volume":"22","author":"Kimura","year":"2004","journal-title":"J. Hypertens."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1016\/S0140-6736(11)61710-8","article-title":"Association of a difference in systolic blood pressure between arms with vascular disease and mortality: A systematic review and meta-analysis","volume":"379","author":"Clark","year":"2012","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Task Force for the management of arterial hypertension of the European Society of Cardiology (2013). 2013 ESH\/ESC guidelines for the management of arterial hypertension. Blood Press., 22, 193\u2013278.","DOI":"10.3109\/08037051.2013.812549"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"27","DOI":"10.2147\/IBPC.S34423","article-title":"Cardio-ankle vascular index (CAVI) as an indicator of arterial stiffness","volume":"6","author":"Sun","year":"2013","journal-title":"Integr. Blood. Press. Control"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1799","DOI":"10.1161\/01.ATV.0000227717.46157.32","article-title":"Variation in the human matrix metalloproteinase-9 gene is associated with arterial stiffness in healthy individuals","volume":"26","author":"McEniery","year":"2006","journal-title":"Arterioscler. Thromb. Vasc. Biol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1301","DOI":"10.1073\/pnas.95.3.1301","article-title":"Aminoguanidine prevents age-related arterial stiffening and cardiac hypertrophy","volume":"95","author":"Corman","year":"1998","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1007\/s003990070033","article-title":"Approximate entropy in cardiology","volume":"11","author":"Pincus","year":"2000","journal-title":"Herzschrittmachertherapie und Elektrophysiologie"},{"key":"ref_9","first-page":"324325","article-title":"Multiscale cross-approximate entropy analysis as a measure of complexity among the aged and diabetic","volume":"2013","author":"Wu","year":"2013","journal-title":"Comput. Math. Methods Med."},{"key":"ref_10","first-page":"231762","article-title":"Multiscale cross-approximate entropy analysis as a measurement of complexity between ECG R-R interval and PPG pulse amplitude series among the normal and diabetic subjects","volume":"2013","author":"Wu","year":"2013","journal-title":"Comput. Math. Methods Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"771","DOI":"10.1007\/s10916-010-9469-0","article-title":"Measuring pulse wave velocity using ECG and photoplethysmography","volume":"35","author":"Liu","year":"2011","journal-title":"J. Med. Syst."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"167","DOI":"10.3109\/08037051.2012.681853","article-title":"Six-channel ECG-based pulse wave velocity for assessing whole-body arterial stiffness","volume":"21","author":"Wu","year":"2012","journal-title":"Blood Press."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"14889","DOI":"10.1073\/pnas.0701020104","article-title":"On the trend, detrending, and variability of nonlinear and nonstationary time series","volume":"104","author":"Wu","year":"2007","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1098\/rspa.1998.0193","article-title":"The empirical mode decomposition and the Hubert spectrum for nonlinear and non-stationary time series analysis","volume":"454","author":"Huang","year":"1998","journal-title":"Proc. R. Soc. A"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Kreuzer, M., Hentschke, H., Antkowiak, B., Schwarz, C., Kochs, E.F., and Schneider, G. (2010). Cross-approximate entropy of cortical local field potentials quantifies effects of anesthesia\u2014A pilot study in rats. BMC Neurosci., 11.","DOI":"10.1186\/1471-2202-11-122"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2083","DOI":"10.1073\/pnas.93.5.2083","article-title":"Randomness and degrees of irregularity","volume":"93","author":"Pincus","year":"1996","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/S0076-6879(00)21192-0","article-title":"Irregularity and asynchrony in biologic network signals","volume":"321","author":"Pincus","year":"2000","journal-title":"Methods Enzymol."},{"key":"ref_18","first-page":"72","article-title":"Approximate entropy and its application to biosignal analysis","volume":"2","author":"Yang","year":"2001","journal-title":"Nonlinear Biomed. Signal Process."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Cheng, D., Tsai, S.J., Hong, C.J., and Yang, A.C. (2009). Reduced physiological complexity in robust elderly adults with the APOE epsilon4 allele. PLoS ONE, 4.","DOI":"10.1371\/journal.pone.0007733"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Lin, G.M., Haryadi, B., Yang, C.M., Chu, S.C., Yang, C.C., and Wu, H.T. (2017). Discrepancies between conventional multiscale entropy and modified short-time multiscale entropy of photoplethysmographic pulse signals in middle- and old-aged individuals with or without diabetes. Entropy, 19.","DOI":"10.3390\/e19030132"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"440","DOI":"10.1161\/01.CIR.11.3.440","article-title":"The effect of intravenous protoveratrine on digital pulse volume and digital skin temperature in hypertensive patients","volume":"11","author":"Currens","year":"1955","journal-title":"Circulation"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1016\/j.atherosclerosis.2010.08.075","article-title":"Novel application of parameters in waveform contour analysis for assessing arterial stiffness in aged and atherosclerotic subjects","volume":"213","author":"Wu","year":"2010","journal-title":"Atherosclerosis"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"618","DOI":"10.1016\/j.jacc.2004.04.044","article-title":"Subclavian artery stenosis: Prevalence, risk factors, and association with cardiovascular diseases","volume":"44","author":"Shadman","year":"2004","journal-title":"J. Am. Coll. Cardiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"068102","DOI":"10.1103\/PhysRevLett.89.068102","article-title":"Multiscale entropy analysis of complex physiologic time series","volume":"89","author":"Costa","year":"2002","journal-title":"Phys. Rev. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1088\/0967-3334\/29\/7\/010","article-title":"Reduced short-term complexity of heart rate and blood pressure dynamics in patients with diabetes mellitus type 1: Multiscale entropy analysis","volume":"29","author":"Trunkvalterova","year":"2008","journal-title":"Physiol. Meas."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1159\/000056362","article-title":"Value of quantitative photoplethysmography for functional vascular diagnostics","volume":"14","author":"Blazek","year":"2001","journal-title":"Skin Pharmacol. Physiol."}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/19\/4\/145\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:31:38Z","timestamp":1760207498000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/19\/4\/145"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,3,30]]},"references-count":26,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2017,4]]}},"alternative-id":["e19040145"],"URL":"https:\/\/doi.org\/10.3390\/e19040145","relation":{},"ISSN":["1099-4300"],"issn-type":[{"value":"1099-4300","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,3,30]]}}}