{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T03:22:56Z","timestamp":1781148176281,"version":"3.54.1"},"reference-count":44,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,11,23]],"date-time":"2025-11-23T00:00:00Z","timestamp":1763856000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"West-Siberian Science and Education Center, Government of Tyumen District","award":["928\u2013rp"],"award-info":[{"award-number":["928\u2013rp"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biology"],"abstract":"<jats:p>Background: Light exposure (LE) and its influence on circadian rhythms are recognized to impact various physiological domains, yet their specific associations with hematological status, particularly in high-latitude environments, remain underexplored. Understanding these links could offer insights into maintaining hematological health. Methods: This study investigated the relationship between 24 h light exposure (LE), blue light exposure (BLE), sleep, and physical activity (PA) and hematological markers in 85 young adults (18\u201325 years). Participants underwent simultaneous 7-day monitoring using actigraphy and RGB sensors, coupled with morning blood sampling for hemoglobin (HGB), hematocrit (HCT), mean corpuscular hemoglobin (MCH), and red blood cell distribution width (RDW-CV). Results: Univariate analyses revealed significant correlations: normalized BLE amplitude (NA BLE) positively correlated with HGB (r = 0.369, p = 0.001) and MCH (r = 0.378, p &lt; 0.001). A later BLE acrophase correlated with lower HGB and MCH, but higher RDW-CV. Later PA acrophase was associated with lower MCH and higher RDW-CV, while later bedtime correlated with lower HGB and MCH. Multivariate regressions confirmed that a larger NA BLE predicted higher HGB (\u03b2 = 0.206, p = 0.037) and MCH (\u03b2 = 0.377, p &lt; 0.001), and an earlier BLE acrophase predicted higher MCH and smaller RDW-CV. Conclusions: Advantageous circadian patterns of BLE and PA are linked to a favorable hematological status in young adults during the light-deficient fall season at higher latitudes, underscoring the importance of optimizing light and activity timing for hematological health.<\/jats:p>","DOI":"10.3390\/biology14121649","type":"journal-article","created":{"date-parts":[[2025,11,24]],"date-time":"2025-11-24T10:24:17Z","timestamp":1763979857000},"page":"1649","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Circadian Light Hygiene Is Associated with Anemia Markers in Young Adults"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2028-1033","authenticated-orcid":false,"given":"Denis","family":"Gubin","sequence":"first","affiliation":[{"name":"Laboratory for Chronobiology and Chronomedicine, Research Institute of Biomedicine and Biomedical Technologies, Tyumen State Medical University, 625023 Tyumen, Russia"},{"name":"Department of Biology, Tyumen State Medical University, 625023 Tyumen, Russia"},{"name":"Tyumen Cardiology Research Center, Tomsk National Research Medical Center, Russian Academy of Science, 625026 Tyumen, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3276-7615","authenticated-orcid":false,"given":"Julia","family":"Boldyreva","sequence":"additional","affiliation":[{"name":"Department of Biology, Tyumen State Medical University, 625023 Tyumen, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3104-3639","authenticated-orcid":false,"given":"Sergey","family":"Kolomeichuk","sequence":"additional","affiliation":[{"name":"Laboratory for Genomics, Metabolomics and Proteomics, Research Institute of Biomedicine and Biomedical Technologies, Tyumen State Medical University, 625023 Tyumen, Russia"},{"name":"Laboratory of Genetics, Institute of Biology, Karelian Research Centre, Russian Academy of Sciences, 185910 Petrozavodsk, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0199-6500","authenticated-orcid":false,"given":"Oliver","family":"Stefani","sequence":"additional","affiliation":[{"name":"Department Engineering and Architecture, Lucerne University of Applied Sciences and Arts, 6048 Horw, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-9782-2413","authenticated-orcid":false,"given":"Aislu","family":"Shigabaeva","sequence":"additional","affiliation":[{"name":"Laboratory for Chronobiology and Chronomedicine, Research Institute of Biomedicine and Biomedical Technologies, Tyumen State Medical University, 625023 Tyumen, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6571-6526","authenticated-orcid":false,"given":"Larisa","family":"Alkhimova","sequence":"additional","affiliation":[{"name":"School of Natural Sciences, University of Tyumen, 625003 Tyumen, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marina","family":"Tchaikovkaya","sequence":"additional","affiliation":[{"name":"Department of Nursing, Tyumen State Medical University, 625023 Tyumen, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dietmar","family":"Weinert","sequence":"additional","affiliation":[{"name":"Department of Zoology, Institute of Biology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1698-1590","authenticated-orcid":false,"given":"Germaine","family":"Cornelissen","sequence":"additional","affiliation":[{"name":"Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1111\/nyas.14092","article-title":"Anemia epidemiology, pathophysiology, and etiology in low- and middle-income countries","volume":"1450","author":"Chaparro","year":"2019","journal-title":"Ann. 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