Temperatures around conception affect metabolic health in adulthood

Temperatures around conception affect metabolic health in adulthood | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Temperatures around conception affect metabolic health in adulthood Timo Stefan Münz, Fabienne Pradella, Nathalie Lambrecht, Sabine Gabrysch, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6324218/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 Mar, 2026 Read the published version in Communications Medicine → Version 1 posted You are reading this latest preprint version Abstract Epigenetic adaptations around conception can help organisms adjust to their future environment. Pre-conception cold exposure is thought to increase active brown fat mass, and as brown fat metabolizes stored energy to generate heat, this helps adjust to life in cold environments. We examine the implications of this process for human metabolic health. We use data on 430,000 individuals born between 1934 and 1971 from the UK Biobank, and match these to historical temperature data. To isolate causal impacts of temperature, we utilize day-specific temperature deviations during the calculated pre-conception period relative to the long-term mean temperature for the same location and day of year. This approach leverages a quasi-random variation in temperature. We find that individuals conceived when temperatures were lower than usual have lower body mass indices (BMI), smaller waist circumferences, and lower levels of triglycerides and total cholesterol in adulthood, while there was no evidence for an effect on glycated hemoglobin (HbA1c). These findings have implications for potential health effects of climate change, and more strongly, for effects of improved indoor insulation. Health sciences/Medical research/Epidemiology Health sciences/Risk factors Scientific community and society/Social sciences/Interdisciplinary studies Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Published Journal Publication published 27 Mar, 2026 Read the published version in Communications Medicine → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6324218","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":446994168,"identity":"bf78f521-8bb2-4451-ac1c-758a436825c9","order_by":0,"name":"Timo Stefan Münz","email":"","orcid":"","institution":"Johannes Gutenberg University Mainz","correspondingAuthor":false,"prefix":"","firstName":"Timo","middleName":"Stefan","lastName":"Münz","suffix":""},{"id":446994169,"identity":"cb191354-5371-46f7-9f57-802fa7dd7c49","order_by":1,"name":"Fabienne Pradella","email":"","orcid":"https://orcid.org/0000-0002-5242-6957","institution":"Johannes Gutenberg University Mainz;Heidelberg Institute of Global Health; Stanford University","correspondingAuthor":false,"prefix":"","firstName":"Fabienne","middleName":"","lastName":"Pradella","suffix":""},{"id":446994170,"identity":"9f42c796-842a-42f0-90ad-ed0bf5a27ffa","order_by":2,"name":"Nathalie Lambrecht","email":"","orcid":"","institution":"Stanford University; Charité - Universitätsmedizin Berlin; Potsdam Institute for Climate Impact Research (PIK)","correspondingAuthor":false,"prefix":"","firstName":"Nathalie","middleName":"","lastName":"Lambrecht","suffix":""},{"id":446994171,"identity":"62a7eb0b-6e21-4409-abfc-722934bdf098","order_by":3,"name":"Sabine Gabrysch","email":"","orcid":"","institution":"Heidelberg Institute of Global Health; Charité - Universitätsmedizin Berlin; Potsdam Institute for Climate Impact Research (PIK)","correspondingAuthor":false,"prefix":"","firstName":"Sabine","middleName":"","lastName":"Gabrysch","suffix":""},{"id":446994167,"identity":"8019a7e3-01f4-4f22-bcfc-48108ccf34fa","order_by":4,"name":"Reyn van Ewijk","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6klEQVRIie3PsWrDMBCAYQmDpqNaFZyHuCBQMIT2VQpe1ZC9gQo6dAlk9ZN4ljE4i0tW7Vk9OFshDkROl0xquhWqH4Q40MchQmKxPxsy5P6y/sA4i7vIxPyOeIT2ZgoS3H1WB1g9SOleKkv143TOLXV9iLTLXAIypdzy2dIyh8zYJCsCZGK0SjWyhXIa63OZAFaGpRAi225+GoksNPotb4A1YekQIFxolXiiUFxJDdh4Evo+F51MB2RStN1IdoAtfc82AcK4nh2LoZltP7Tsafn6hPu6cl+hNd81twM1PwNC1vc8isVisf/aBe7NRmJ5TwATAAAAAElFTkSuQmCC","orcid":"","institution":"Johannes Gutenberg University Mainz","correspondingAuthor":true,"prefix":"","firstName":"Reyn","middleName":"van","lastName":"Ewijk","suffix":""}],"badges":[],"createdAt":"2025-03-28 02:45:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6324218/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6324218/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s43856-026-01496-8","type":"published","date":"2026-03-27T04:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":105618223,"identity":"6f3df974-e52e-4667-8674-7f164fbf8df9","added_by":"auto","created_at":"2026-03-28 07:10:56","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1245116,"visible":true,"origin":"","legend":"Article File","description":"","filename":"MainManuscript20250327.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6324218/v1_covered_fdbbc710-2f3f-4a68-b4f4-17ffe9a771d1.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Temperatures around conception affect metabolic health in adulthood","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6324218/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6324218/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Epigenetic adaptations around conception can help organisms adjust to their future environment. Pre-conception cold exposure is thought to increase active brown fat mass, and as brown fat metabolizes stored energy to generate heat, this helps adjust to life in cold environments. We examine the implications of this process for human metabolic health. We use data on 430,000 individuals born between 1934 and 1971 from the UK Biobank, and match these to historical temperature data. To isolate causal impacts of temperature, we utilize day-specific temperature deviations during the calculated pre-conception period relative to the long-term mean temperature for the same location and day of year. This approach leverages a quasi-random variation in temperature. We find that individuals conceived when temperatures were lower than usual have lower body mass indices (BMI), smaller waist circumferences, and lower levels of triglycerides and total cholesterol in adulthood, while there was no evidence for an effect on glycated hemoglobin (HbA1c). These findings have implications for potential health effects of climate change, and more strongly, for effects of improved indoor insulation.","manuscriptTitle":"Temperatures around conception affect metabolic health in adulthood","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-19 02:50:30","doi":"10.21203/rs.3.rs-6324218/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"communications-medicine","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"commsmed","sideBox":"Learn more about [Communications Medicine](http://www.nature.com/commsmed)","snPcode":"43856","submissionUrl":"https://mts-commsmed.nature.com/cgi-bin/main.plex","title":"Communications Medicine","twitterHandle":"@commsmedicine","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Communications Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"72e7bf13-fa39-40f9-a452-a067fcd0ae8b","owner":[],"postedDate":"May 19th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":47578448,"name":"Health sciences/Medical research/Epidemiology"},{"id":47578449,"name":"Health sciences/Risk factors"},{"id":47578450,"name":"Scientific community and society/Social sciences/Interdisciplinary studies"}],"tags":[],"updatedAt":"2026-03-28T07:10:21+00:00","versionOfRecord":{"articleIdentity":"rs-6324218","link":"https://doi.org/10.1038/s43856-026-01496-8","journal":{"identity":"communications-medicine","isVorOnly":false,"title":"Communications Medicine"},"publishedOn":"2026-03-27 04:00:00","publishedOnDateReadable":"March 27th, 2026"},"versionCreatedAt":"2025-05-19 02:50:30","video":"","vorDoi":"10.1038/s43856-026-01496-8","vorDoiUrl":"https://doi.org/10.1038/s43856-026-01496-8","workflowStages":[]},"version":"v1","identity":"rs-6324218","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6324218","identity":"rs-6324218","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}