{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T23:44:33Z","timestamp":1787787873815,"version":"build-2784847793"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T00:00:00Z","timestamp":1776816000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cardiovasc. Med."],"abstract":"<jats:p>The determination of blood pressure (BP) is crucial for the regulation of cardiovascular health status, particularly under the condition of physiological stress as seen during Ramadan fasting. Conventional BP measurement techniques are, accurate, intermittent and do not reflect the dynamic changes of fasting and rehydration. Wrist\u2014based wearable oscillometric blood pressure monitoring devices, incorporating miniaturized inflatable cuffs, provide a portable and non\u2014invasive approach for assessing BP outside traditional clinical settings. To assess the reliability of a consumer\u2014grade wearable device (Huawei Watch D) for measuring systolic and diastolic blood pressure during Ramadan fasting, and to compare its performance with a validated electronic upper-arm monitor after pre-fast and post\u2014fast conditions (Sahoor and If tar).<\/jats:p>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A within subject, repeated\u2014measures investigation was performed with 101 healthy fasting subjects (ages 22\u201470). Each participant recorded BP twice daily during Sahoor and If tar using both the Huawei Watch D and an upper\u2014arm electronic monitor, both are FDA-approved. Statistical methods comprised paired t tests, as well as Pearson correlations and Bland\u2014Altman plots. To evaluate prediction accuracy and discover subgroups, we also used machine learning approaches (linear regression and K\u2014means clustering).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Compared with the electronic upper-arm monitor, the Huawei Watch D demonstrated minimal mean bias for both systolic and diastolic blood pressure (SBP: +0.9 to +1.4\u2005mmHg; DBP: \u22120.6 to \u22120.2\u2005mmHg). However, SBP exhibited wide limits of agreement (\u00b118\u201321\u2005mmHg), whereas DBP showed narrower dispersion (\u00b111\u201313\u2005mmHg). Machine-learning models achieved moderate prediction accuracy for DBP (MAE \u2248 4.3\u20136.1\u2005mmHg, R\u00b2 up to 0.74), while SBP prediction remained less accurate (MAE \u2248 6.5\u20138.9\u2005mmHg, R\u00b2 up to 0.64).However, SBP exhibited wide limits of agreement (\u00b120\u2005mmHg), limiting diagnostic interchangeability. DBP showed narrower error dispersion, supporting the use of wearable devices for trend monitoring and screening rather than clinical diagnosis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Smartwatch BP estimates are associated with standard devices, however, individual differences are considerable and therefore do not allow for diagnostic interchangeability. Wearables, such as the Huawei Watch D, provide the interesting data on the BP trend during fasting and rehydration, especially in diastolic pressure. These devices may assist with culturally appropriate monitoring and early identification of BP abnormalities however are in need of validation in a clinical context.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fcvm.2026.1655897","type":"journal-article","created":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T05:48:40Z","timestamp":1776836920000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Wrist-based wearable oscillometric blood pressure monitoring during Ramadan: a comparative study with standard devices"],"prefix":"10.3389","volume":"13","author":[{"given":"Eyad Talal","family":"Attar","sequence":"first","affiliation":[{"name":"Department of Electrical and Computer Engineering, King Abdulaziz University","place":["Jeddah, Saudi Arabia"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,22]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1038\/s41371-022-00693-x","article-title":"Automated oscillometric blood pressure measuring devices: how they work and what they measure","volume":"37","author":"Sharman","year":"2023","journal-title":"J Hum Hypertens"},{"key":"B2","doi-asserted-by":"publisher","first-page":"1665","DOI":"10.1097\/HJH.0000000000000969","article-title":"Methodology and technology for peripheral and central blood pressure and blood pressure variability measurement: current status and future directions - position statement of the European society of hypertension working group on blood pressure monitoring and cardiovascular variability","volume":"34","author":"Stergiou","year":"2016","journal-title":"J Hypertens"},{"key":"B3","doi-asserted-by":"publisher","first-page":"e029297","DOI":"10.1161\/JAHA.122.029297","article-title":"Blood pressure variability in clinical practice: past, present, and future","volume":"12","author":"Sheikh","year":"2023","journal-title":"J Am Heart Assoc"},{"key":"B4","doi-asserted-by":"publisher","first-page":"258","DOI":"10.1136\/heartjnl-2021-319273","article-title":"Ramadan fasting: recommendations for patients with cardiovascular disease","volume":"108","author":"Akhtar","year":"2022","journal-title":"Heart (British Cardiac Society)"},{"key":"B5","doi-asserted-by":"publisher","first-page":"e1","DOI":"10.4102\/safp.v66i1.5805","article-title":"Ramadhan fasting for people living with chronic illness: a narrative literature review","volume":"66","author":"Ras","year":"2024","journal-title":"S Afr Fam Pract (2004)"},{"key":"B6","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1016\/j.numecd.2021.09.004","article-title":"Dietary patterns in association with the risk of elevated blood pressure, lipid profile and fasting plasma glucose among adults in Jiangsu province of China","volume":"32","author":"Wang","year":"2022","journal-title":"Nutr Metab Cardiovasc Dis"},{"key":"B7","doi-asserted-by":"publisher","first-page":"2050312120965780","DOI":"10.1177\/2050312120965780","article-title":"Effects of Ramadan fasting on anthropometric measures, blood pressure, and lipid profile among hypertensive patients in the Kurdistan region of Iraq","volume":"8","author":"Farag","year":"2020","journal-title":"SAGE Open Med"},{"key":"B8","doi-asserted-by":"publisher","first-page":"357","DOI":"10.1097\/MBP.0000000000000619","article-title":"Sleep characteristics associated with nocturnal blood pressure nondipping in healthy individuals: a systematic review","volume":"27","author":"Forshaw","year":"2022","journal-title":"Blood Press Monit"},{"key":"B9","doi-asserted-by":"publisher","first-page":"1533","DOI":"10.5664\/jcsm.10566","article-title":"The association between sleep disturbances and blood pressure variability: a review of the literature","volume":"19","author":"Haddad","year":"2023","journal-title":"J Clin Sleep Med"},{"key":"B10","doi-asserted-by":"publisher","first-page":"195","DOI":"10.15406\/ijbsbe.2018.04.00125","article-title":"A review on wearable photoplethysmography sensors and their potential future applications in health care","volume":"4","author":"Castaneda","year":"2018","journal-title":"Int J Biosens Bioelectron"},{"key":"B11","doi-asserted-by":"publisher","first-page":"2439","DOI":"10.1109\/JBHI.2024.3499834","article-title":"Wearable PPG based BP estimation methods: a systematic review and meta-analysis","volume":"29","author":"Sastimoglu","year":"2025","journal-title":"IEEE J Biomed Health Inform"},{"key":"B12","doi-asserted-by":"publisher","first-page":"e144","DOI":"10.1016\/S2589-7500(23)00002-X","article-title":"Effectiveness, reach, uptake, and feasibility of digital health interventions for adults with hypertension: a systematic review and meta-analysis of randomised controlled trials","volume":"5","author":"Siopis","year":"2023","journal-title":"Lancet Digit Health"},{"key":"B13","doi-asserted-by":"publisher","first-page":"e101261","DOI":"10.1136\/bmjhci-2024-101261","article-title":"Digital health tools in hypertension management in Sub-Saharan Africa: a scoping review of barriers and facilitators of adoption into mainstream healthcare","volume":"32","author":"Hinneh","year":"2025","journal-title":"BMJ Health Care Inform"},{"key":"B14","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1038\/s41746-023-00835-6","article-title":"Emerging sensing and modeling technologies for wearable and cuffless blood pressure monitoring","volume":"6","author":"Zhao","year":"2023","journal-title":"NPJ Digit Med"},{"key":"B15","doi-asserted-by":"publisher","first-page":"828","DOI":"10.3390\/s23020828","article-title":"Smart wearables for the detection of cardiovascular diseases: a systematic literature review","volume":"23","author":"Moshawrab","year":"2023","journal-title":"Sensors (Basel, Switzerland)"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1113\/EP093286","article-title":"Comparison of blood pressure measurements between the Huawei watch D smartwatch application and the validated omron M3 intellisense device: observational study","author":"Vel\u00e1zquez Saornil","year":"2025","journal-title":"Exp Physiol"},{"key":"B17","doi-asserted-by":"publisher","first-page":"2961","DOI":"10.1038\/s41440-025-02345-2","article-title":"Accuracy of a wearable watch-type oscillometric blood pressure monitor in rest and ambulatory blood pressure measurements","volume":"48","author":"Zhou","year":"2025","journal-title":"Hypertens Res"},{"key":"B18","doi-asserted-by":"publisher","first-page":"355","DOI":"10.1109\/JPROC.2022.3149785","article-title":"Wearable photoplethysmography for cardiovascular monitoring","volume":"110","author":"Charlton","year":"2022","journal-title":"Proc IEEE Inst Electr Electron Eng"},{"key":"B19","doi-asserted-by":"publisher","first-page":"R542","DOI":"10.1152\/ajpregu.00283.2021","article-title":"Influence of an acute fast on ambulatory blood pressure and autonomic cardiovascular control","volume":"322","author":"Gonzalez","year":"2022","journal-title":"Am J Physiol Regul Integr Comp Physiol"},{"key":"B20","doi-asserted-by":"publisher","first-page":"e20220756","DOI":"10.36660\/abc.20220756","article-title":"Improvement in blood pressure after intermittent fasting in hypertension: could renin\u2013angiotensin system and autonomic nervous system have a role?","volume":"120","author":"Demirci","year":"2023","journal-title":"Arq Bras Cardiol"},{"key":"B21","doi-asserted-by":"publisher","first-page":"1611096","DOI":"10.3389\/fphys.2025.1611096","article-title":"Oscillometric blood pressure measurement: modeling and analysis of the area oscillogram and height oscillogram","volume":"16","author":"Dhamotharan","year":"2025","journal-title":"Front Physiol"},{"key":"B22","doi-asserted-by":"publisher","first-page":"629","DOI":"10.1038\/s41569-025-01127-0","article-title":"Wearable blood pressure sensors for cardiovascular monitoring and machine learning algorithms for blood pressure estimation","volume":"22","author":"Min","year":"2025","journal-title":"Nat Rev Cardiol"},{"key":"B23","doi-asserted-by":"publisher","first-page":"891","DOI":"10.1038\/s41430-021-01053-7","article-title":"Impact of religious fasting on metabolic and hematological profile in both dyslipidemic and non-dyslipidemic fasters","volume":"76","author":"Papazoglou","year":"2022","journal-title":"Eur J Clin Nutr"},{"key":"B24","doi-asserted-by":"publisher","first-page":"9","DOI":"10.3390\/jpm13010009","article-title":"Validations of blood pressure measuring devices using recognized protocols","volume":"13","author":"Mazoteras-Pardo","year":"2022","journal-title":"J Pers Med"},{"key":"B25","doi-asserted-by":"publisher","first-page":"5589","DOI":"10.3390\/s21165589","article-title":"Review of wearable devices and data collection considerations for connected health","volume":"21","author":"Vijayan","year":"2021","journal-title":"Sensors"},{"key":"B26","doi-asserted-by":"publisher","first-page":"e021560","DOI":"10.1161\/JAHA.120.021560","article-title":"Effect of religious fasting in ramadan on blood pressure: results from LORANS (London Ramadan study) and a meta-analysis","volume":"10","author":"Al-Jafar","year":"2021","journal-title":"J Am Heart Assoc"},{"key":"B27","doi-asserted-by":"publisher","first-page":"953","DOI":"10.1007\/s12529-024-10296-0","article-title":"Effects of modified Ramadan fasting on mental well-being and biomarkers in healthy adult muslims \u2014 a randomised controlled trial","volume":"32","author":"Lauche","year":"2025","journal-title":"Int J Behav Med"},{"key":"B28","doi-asserted-by":"publisher","first-page":"6610455","DOI":"10.1155\/2021\/6610455","article-title":"Impact of Ramadan intermittent fasting on heart rate variability and cardiovascular parameters in patients with controlled hypertension","volume":"2021","author":"Hammoud","year":"2021","journal-title":"J Nutr Metab"},{"key":"B29","doi-asserted-by":"publisher","first-page":"1576424","DOI":"10.3389\/fspor.2025.1576424","article-title":"A case study on the impact of ramadan on biomechanical and physiological markers in a female collegiate student-athlete","volume":"7","author":"Amitrano","year":"2025","journal-title":"Front Sports Act Living"},{"key":"B30","doi-asserted-by":"publisher","first-page":"643","DOI":"10.1038\/s41569-022-00690-0","article-title":"Blood pressure and its variability: classic and novel measurement techniques","volume":"19","author":"Schutte","year":"2022","journal-title":"Nat Rev Cardiol"},{"key":"B31","doi-asserted-by":"publisher","first-page":"e467","DOI":"10.1016\/S2589-7500(23)00087-0","article-title":"Wearable technology and the cardiovascular system: the future of patient assessment","volume":"5","author":"Williams","year":"2023","journal-title":"Lancet Digit Health"},{"key":"B32","doi-asserted-by":"publisher","first-page":"2414","DOI":"10.3390\/s18082414","article-title":"Wearable health devices-vital sign monitoring, systems and technologies","volume":"18","author":"Dias","year":"2018","journal-title":"Sensors (Basel, Switzerland)"},{"key":"B33","doi-asserted-by":"publisher","first-page":"8942","DOI":"10.1038\/s41598-025-93527-y","article-title":"An innovative approach based on health surveillance for the prevention and early detection of cardiovascular diseases in a large cohort of healthcare workers","volume":"15","author":"Vimercati","year":"2025","journal-title":"Sci Rep"}],"container-title":["Frontiers in Cardiovascular Medicine"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcvm.2026.1655897\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,22]],"date-time":"2026-04-22T05:48:41Z","timestamp":1776836921000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcvm.2026.1655897\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,22]]},"references-count":33,"alternative-id":["10.3389\/fcvm.2026.1655897"],"URL":"https:\/\/doi.org\/10.3389\/fcvm.2026.1655897","relation":{},"ISSN":["2297-055X"],"issn-type":[{"value":"2297-055X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,22]]},"article-number":"1655897"}}