{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T16:15:34Z","timestamp":1790007334088,"version":"4.0.1"},"reference-count":54,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T00:00:00Z","timestamp":1774396800000},"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. Endocrinol."],"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To explore the effects of temperature and relative humidity on the tongue color of diabetic patients with different severity levels and their interactions.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A total of 1,711 participants were included, divided into five groups based on disease status (no diabetes, simple diabetes, diabetes with hypertension, diabetes with coronary heart disease, diabetes with both hypertension and coronary heart disease). RGB values of the tongue body and coating at five sites (tip, middle, root, left, and right) were collected (30 indicators in total). The month of visit (six categories) was used as a composite temperature-humidity proxy variable, with age, gender, BMI, smoking, and alcohol consumption as covariates. Multiple linear regression was conducted, including the interaction term of month \u00d7 group, to perform Type III tests and FDR corrections for the 30 RGB indicators and principal component scores.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Significant interaction effects were found between the month of visit and disease group on tongue color (PC1: F(20,1670)=12.87, P&amp;lt;0.0001; PC2: F(20,1670)=18.64, P&amp;lt;0.0001). In the diabetes with hypertension and coronary heart disease group, tongue redness and brightness increased by 2.74\u20133.19 standard deviations during the hot and humid months of July and August compared to colder months (P&amp;lt;0.0001), while the no diabetes group remained stable throughout the year. Forty-seven RGB interaction terms had FDR &amp;lt;0.05, with the ten most significant located at the tongue tip; the R-value of the tongue body was significantly associated with temperature increase, showing a clear dose-response relationship with the severity of complications (trend P&amp;lt;10\n                      <jats:sup>-<\/jats:sup>\n                      \u00b9\u00b2).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>High temperature and humidity can significantly amplify tongue redness in diabetic patients, potentially involving a microcirculation expansion-endothelial dysfunction-oxidative stress cascade pathway, while tongue color remains highly stable in healthy individuals. This interaction effect suggests that RGB tongue indicators may serve as an objective dynamic biomarker reflecting cardiovascular metabolic risk under heat stress.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fendo.2026.1772207","type":"journal-article","created":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T05:50:36Z","timestamp":1774417836000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Temperature and humidity-dependent interaction effects on tongue color in diabetic patients: a quantitative analysis and TCM perspective"],"prefix":"10.3389","volume":"17","author":[{"given":"Bingnan","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naijin","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huixia","family":"Ren","sequence":"additional","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yonghui","family":"Li","sequence":"additional","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haiyan","family":"Du","sequence":"additional","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tingjing","family":"Ren","sequence":"additional","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiayu","family":"Huang","sequence":"additional","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongwu","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Public Health and Health Sciences, Tianjin University of Traditional Chinese Medicine","place":["Tianjin, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,3,25]]},"reference":[{"key":"B1","volume-title":"IDF Diabetes Atlas","year":"2021"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.2196\/56024","article-title":"Objective analysis of traditional Chinese medicine syndrome differentiation of patients with diabetes and prediabetes: protocol for a nonrandomized, exploratory, observational case-control study using digitalized traditional Chinese medicine diagnostic tools","volume":"13","author":"Ng","year":"2024","journal-title":"JMIR Res Protoc"},{"key":"B3","first-page":"78","volume-title":"Huangdi Neijing \u00b7 Suwen (Plain Questions)","year":"2008"},{"key":"B4","volume-title":"Tongue Diagnosis in Traditional Chinese Medicine","author":"Wang","year":"2018"},{"key":"B5","article-title":"Huangdi Neijing Suwen, Chapter 74","volume-title":"Zhi Zhen Yao Da Lun","year":"2008"},{"key":"B6","first-page":"8371946","article-title":"A review of tongue diagnosis objectification research in the past 20 years","volume":"2020","author":"Zhang","year":"2020","journal-title":"Evid Based Complem Alternat Med"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.19945\/j.cnki.issn.1006-3250.2022.04.025","article-title":"Research status and prospects of seasonal influence on tongue manifestation in TCM","volume":"28","author":"Hu","year":"2022","journal-title":"Chin J Bas Med Trad Chin Med"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00695.2011","article-title":"Sympathetic nerve activity and whole body heat stress in humans","volume":"111","author":"Low","year":"2011","journal-title":"J Appl Physiol"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1093\/eurheartj\/eht149","article-title":"Diabetes and vascular disease: pathophysiology, clinical consequences, and medical therapy: part I","volume":"34","author":"Paneni","year":"2013","journal-title":"Eur Heart J"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/j.tips.2006.07.008","article-title":"Methodological issues in the assessment of skin microvascular endothelial function in humans","volume":"27","author":"Cracowski","year":"2006","journal-title":"Trends Pharmacol Sci"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.4065\/78.5.603","article-title":"Skin blood flow in adult human thermoregulation: how it works, when it does not, and why","volume":"78","author":"Charkoudian","year":"2003","journal-title":"Mayo Clin Proc"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1016\/j.cjca.2017.12.005","article-title":"Diabetes, hypertension, and cardiovascular disease: clinical insights and vascular mechanisms","volume":"34","author":"Petrie","year":"2018","journal-title":"Can J Cardiol"},{"key":"B13","doi-asserted-by":"publisher","first-page":"53","DOI":"10.3760\/cma.j.cn115791-20210221-00095","article-title":"Endothelial dysfunction in diabetes mellitus: molecular mechanisms and clinical implications","volume":"21","author":"Tabit","year":"2020","journal-title":"Rev Endocr Metab Disord"},{"key":"B14","doi-asserted-by":"publisher","first-page":"315","DOI":"10.3760\/cma.j.cn115791-20210221-00095","article-title":"China guideline for type 2 diabetes (2020 edition)","volume":"13","year":"2021","journal-title":"Chin J Diabetes Mellit"},{"key":"B15","doi-asserted-by":"crossref","DOI":"10.1097\/MD.0000000000038575","article-title":"Association between color value of tongue and T2DM based on dose-response analyses using restricted cubic splines in China: A cross-sectional study","volume":"103","author":"Tian","year":"2024","journal-title":"Medicine (Baltimore)"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1007\/s11548-019-02076-z","article-title":"Tongue color clustering and visual application based on 2D information","volume":"15","author":"Jiao","year":"2020","journal-title":"Int J Comput Assist Radiol Surg"},{"key":"B17","article-title":"How to understand interaction effects in moderated multiple regression","volume":"21","author":"Kraemer","year":"2016","journal-title":"Psychol Methods"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.13192\/j.issn.1000-1719.2023.01.036","article-title":"Seasonal variation of meteorological factors and its influence on tongue manifestation in diabetic patients","volume":"50","author":"Liu","year":"2023","journal-title":"Liaoning J Trad Chin Med"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2024.1477638","article-title":"Application of tongue image characteristics and oral-gut microbiota in predicting pre-diabetes and type 2 diabetes with machine learning","volume":"14","author":"Deng","year":"2024","journal-title":"Front Cell Infect Microbiol"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.2337\/dc23-S002","article-title":"Classification and Diagnosis of Diabetes: Standards of Care in Diabetes\u20142023","volume":"46","author":"ElSayed","year":"2023","journal-title":"Diabetes Care"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1161\/HYPERTENSIONAHA.120.15026","article-title":"International Society of Hypertension Global Hypertension Practice Guidelines","volume":"75","author":"ElSayed","year":"2020","journal-title":"Hypertension"},{"key":"B22","volume-title":"China Meteorological Yearbook 2022","year":"2022"},{"key":"B23","first-page":"1","volume-title":"China Meteorological Yearbook 2023","year":"2023"},{"key":"B24","first-page":"3","volume-title":"Preface to CHINA Meteorological Yearbook","year":"2022"},{"key":"B25","volume-title":"Monthly mean temperature and relative humidity data of national surface meteorological stations (2022\u20132023)","year":"2023"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1503\/cmaj.081050","article-title":"Heat stress in older individuals and patients with common chronic diseases","volume":"182","author":"Kenny","year":"2010","journal-title":"CMAJ"},{"key":"B27","doi-asserted-by":"publisher","first-page":"289","DOI":"10.1111\/j.2517-6161.1995.tb02031.x","article-title":"Controlling the false discovery rate: a practical and powerful approach to multiple testing","volume":"57","author":"Benjamini","year":"1995","journal-title":"J R Stat Soc: Ser B (Methodol)"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1111\/j.1541-0420.2007.00935.x","article-title":"Screening for partial conjunction hypotheses","volume":"64","author":"Benjamini","year":"2008","journal-title":"Biometrics"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.19852\/j.cnki.jtcm.20231018.003","article-title":"Dark red tongue color formation caused by hyperglycemia is attributed to decreased blood flow of tongue tissue partially due to nuclear factor-kappa B pathway activation","volume":"43","author":"Shenyi","year":"2023","journal-title":"J Tradit Chin Med"},{"key":"B30","first-page":"296","article-title":"Seasonal variation in tongue appearance of healthy Japanese subjects","volume":"34","author":"Yamamoto","year":"2014","journal-title":"J Trad Chin Med"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1007\/s00484-025-03040-0","article-title":"Effect of temperature and relative humidity on hospitalization for type 2 diabetes mellitus with complications","volume":"69","author":"Jin","year":"2025","journal-title":"Int J Biometeorol"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.19945\/j.cnki.issn.1006-3250.2022.11.006","article-title":"Correlation between tongue body red value and cardiovascular risk factors in diabetic patients","volume":"28","author":"Sun","year":"2022","journal-title":"Chin J Bas Med Tradit Chin Med"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.16294\/j.cnki.1007-659x.2025.05.001","article-title":"Traditional Chinese culture and traditional Chinese medicine","volume":"49","author":"Wang","year":"2025","journal-title":"J Shandong Univ Tradit Chin Med"},{"key":"B34","volume-title":"Huangdi Neijing Suwen, Chapter 17 \u201cMai Yao Jing Wei Lun\u201d","year":"2008"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.13192\/j.issn.1000-1719.2020.05.056","article-title":"Research progress on influence of seasonal factors on tongue manifestation","volume":"47","author":"Li","year":"2020","journal-title":"Liaoning J Trad Chin Med"},{"key":"B36","doi-asserted-by":"publisher","first-page":"S1","DOI":"10.2337\/dc23-SINT","article-title":"Standards of medical care in diabetes\u20142023","volume":"46","year":"2023","journal-title":"Diabetes Care"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1128\/spectrum.01459-24","article-title":"Integrated multi-omics analysis reveals the functional signature of microbes and metabolomics in pre-diabetes individuals","volume":"13","author":"Liu","year":"2025","journal-title":"Microbiol Spectr"},{"key":"B38","doi-asserted-by":"publisher","DOI":"10.3389\/frai.2025.1662577","article-title":"An explainable dual-modal diagnostic model for coronary artery disease: a feature-gated approach using tongue and facial image features","volume":"8","author":"Zhao","year":"2025","journal-title":"Front Artif Intell"},{"key":"B39","article-title":"Huangdi Neijing Suwen (Plain Questions)","volume-title":"Chapter 5: Yin Yang Ying Xiang Da Lun","year":"2008"},{"key":"B40","doi-asserted-by":"publisher","DOI":"10.1016\/j.imr.2018.03.001","article-title":"Advances in automated tongue diagnosis techniques","volume":"8","author":"Tania","year":"2019","journal-title":"Integr Med Res"},{"key":"B41","doi-asserted-by":"publisher","DOI":"10.1111\/micc.12257","article-title":"Current methods to assess human cutaneous blood flow: an updated focus on laser-based techniques","volume":"23","author":"Cracowski","year":"2016","journal-title":"Microcirculation"},{"key":"B42","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00298.2010","article-title":"Mechanisms and modifiers of reflex induced cutaneous vasodilation and vasoconstriction in humans","volume":"109","author":"Charkoudian","year":"2010","journal-title":"J Appl Physiol"},{"key":"B43","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1998.85.1.175","article-title":"Thermoregulatory reflexes and cutaneous active vasodilation during heat stress in hypertensive humans","volume":"85","author":"Kellogg","year":"1998","journal-title":"J Appl Physiol (1985)"},{"key":"B44","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00768.2016","article-title":"Effect of hypohydration on thermoregulatory responses in men with low and high body fat exercising in the heat","volume":"122","author":"Tucker","year":"2017","journal-title":"J Appl Physiol (1985)"},{"key":"B45","doi-asserted-by":"publisher","DOI":"10.1093\/cvr\/cvae047","article-title":"SGLT2 inhibitors: from glucose-lowering to cardiovascular benefits","volume":"120","author":"Preda","year":"2024","journal-title":"Cardiovasc Res"},{"key":"B46","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCRESAHA.116.309326","article-title":"Roles of vascular oxidative stress and nitric oxide in the pathogenesis of atherosclerosis","volume":"120","author":"F\u00f6rstermann","year":"2017","journal-title":"Circ Res"},{"key":"B47","doi-asserted-by":"publisher","DOI":"10.1152\/physrev.00045.2011","article-title":"Mechanisms of diabetic complications","volume":"93","author":"Forbes","year":"2013","journal-title":"Physiol Rev"},{"key":"B48","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.2000.89.2.749","article-title":"Aging reduces adaptive capacity and stress protein expression in the liver after heat stress","volume":"89","author":"Hall","year":"2000","journal-title":"J Appl Physiol"},{"key":"B49","article-title":"Altered thermal hyperemia in human skin by prior local heating: a role for enhanced endothelial nitric oxide","volume":"126","author":"Wong","year":"2019","journal-title":"J Appl Physiol"},{"key":"B50","volume-title":"Huangdi Neijing Lingshu, Chapter 47 \u201cBen Shu\u201d","year":"2008"},{"key":"B51","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMra1615439","article-title":"Diabetic foot ulcers and their recurrence","volume":"376","author":"Armstrong","year":"2017","journal-title":"New Engl N Engl J Med"},{"key":"B52","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0b013e3181621311","article-title":"Response of the myocardium to exercise: sex-specific regulation of hsp70","volume":"40","author":"Milne","year":"2008","journal-title":"Med Sci Sports Exerc"},{"key":"B53","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2013.2282625","article-title":"Detecting diabetes mellitus and nonproliferative diabetic retinopathy using tongue color, texture, and geometry features","volume":"61","author":"Zhang","year":"2014","journal-title":"IEEE Trans Biomed Eng"},{"key":"B54","doi-asserted-by":"publisher","DOI":"10.2337\/dc24-S012","article-title":"Cardiovascular disease and risk management: Standards of Care in Diabetes\u20142024","volume":"47","year":"2024","journal-title":"Diabetes Care"}],"container-title":["Frontiers in Endocrinology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2026.1772207\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,25]],"date-time":"2026-03-25T05:50:47Z","timestamp":1774417847000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fendo.2026.1772207\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,25]]},"references-count":54,"alternative-id":["10.3389\/fendo.2026.1772207"],"URL":"https:\/\/doi.org\/10.3389\/fendo.2026.1772207","relation":{},"ISSN":["1664-2392"],"issn-type":[{"value":"1664-2392","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,25]]},"article-number":"1772207"}}