{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T11:04:56Z","timestamp":1785323096324,"version":"3.55.0"},"reference-count":19,"publisher":"F1000 Research Ltd","license":[{"start":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T00:00:00Z","timestamp":1777507200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["218495\/Z\/19\/Z"],"award-info":[{"award-number":["218495\/Z\/19\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011856","name":"MRC","doi-asserted-by":"publisher","award":["MC_UU_00032\/3"],"award-info":[{"award-number":["MC_UU_00032\/3"]}],"id":[{"id":"10.13039\/501100011856","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011856","name":"MRC","doi-asserted-by":"publisher","award":["MC_UU_00032\/5"],"award-info":[{"award-number":["MC_UU_00032\/5"]}],"id":[{"id":"10.13039\/501100011856","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["wellcomeopenresearch.org"],"crossmark-restriction":false},"short-container-title":["Wellcome Open Res"],"abstract":"<ns5:p>Background Mendelian randomisation (MR) studies have been used to investigate whether higher body mass index causally influences blood pressure outcomes. However, conclusions vary across studies, potentially reflecting differences in risk of bias, populations and analytical methods. This systematic review aims to synthesise MR evidence on the effect of variation in adulthood body mass index (BMI) on blood pressure outcomes. Methods We will search three databases (Embase, MEDLINE and Science Citation Index). Two reviewers will independently screen titles and abstracts and full texts for inclusion according to eligibility criteria. Data will be extracted into predefined tables using Microsoft Excel. Risk of bias and certainty of evidence will be assessed using modified risk-of-bias tools and Grading of Recommendations, Assessment, Development, and Evaluation approach (GRADE), respectively. The evidence will then be synthesised and presented in figures and tables, as appropriate. The reporting of this systematic review will follow the PRISMA-2020 guidelines. Anticipated findings By comparing methods and results and potentially meta-analysing results, we will be able to precisely estimate the magnitude and likelihood of the causal effect of adulthood BMI on blood pressure. As well as examining whether the findings are consistent across studies, we will also determine risk of bias for each exposure-outcome pair. We will establish sources of between study heterogeneity. In subsequent work, this systematic review will be triangulated with evidence from randomised controlled trials.<\/ns5:p>","DOI":"10.12688\/wellcomeopenres.26288.1","type":"journal-article","created":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T06:39:10Z","timestamp":1777531150000},"page":"250","update-policy":"https:\/\/doi.org\/10.12688\/wellcomeopenres.crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["The effect of genetically predicted higher adulthood body mass index on blood pressure traits: A protocol for a systematic review and meta-analysis of Mendelian randomisation studies."],"prefix":"10.12688","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1945-3371","authenticated-orcid":false,"given":"Winfred","family":"Gatua","sequence":"first","affiliation":[{"name":"MRC Integrative Epidemiology Unit Bristol England BS1 5DS University of Bristol Medical School"},{"name":"Population Health Sciences Bristol England BS1 5DS University of Bristol Medical School"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ge","family":"Chen","sequence":"additional","affiliation":[{"name":"Bristol Dental School Bristol England University of Bristol Dental Hospital"},{"name":"Department of Clinical and Biological Sciences Exeter England University of Exeter"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9687-8560","authenticated-orcid":false,"given":"Farhad","family":"Shokraneh","sequence":"additional","affiliation":[{"name":"Centre for Academic Primary Care Bristol England BS8 2PS University of Bristol Medical School"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Liu","sequence":"additional","affiliation":[{"name":"MRC Integrative Epidemiology Unit Bristol England BS1 5DS University of Bristol Medical School"},{"name":"Population Health Sciences Bristol England BS1 5DS University of Bristol Medical School"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6793-2262","authenticated-orcid":false,"given":"Deborah A","family":"Lawlor","sequence":"additional","affiliation":[{"name":"MRC Integrative Epidemiology Unit Bristol England BS1 5DS University of Bristol Medical School"},{"name":"Population Health Sciences Bristol England BS1 5DS University of Bristol Medical School"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julian PT","family":"Higgins","sequence":"additional","affiliation":[{"name":"MRC Integrative Epidemiology Unit Bristol England BS1 5DS University of Bristol Medical School"},{"name":"Population Health Sciences Bristol England BS1 5DS University of Bristol Medical School"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tom.R.","family":"Gaunt","sequence":"additional","affiliation":[{"name":"MRC Integrative Epidemiology Unit Bristol England BS1 5DS University of Bristol Medical School"},{"name":"Population Health Sciences Bristol England BS1 5DS University of Bristol Medical School"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"2560","published-online":{"date-parts":[[2026,4,30]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1-22","DOI":"10.1093\/ije\/dyg070","article-title":"\u2018Mendelian randomization\u2019: can genetic epidemiology contribute to understanding environmental determinants of disease?*.","volume":"32","author":"G Davey Smith","year":"2003","journal-title":"Int. J. Epidemiol."},{"key":"ref2","doi-asserted-by":"publisher","first-page":"722-729","DOI":"10.1093\/ije\/29.4.722","article-title":"An introduction to instrumental variables for epidemiologists.","volume":"29","author":"S Greenland","year":"2000","journal-title":"Int. J. Epidemiol."},{"key":"ref3","doi-asserted-by":"publisher","first-page":"164-168","DOI":"10.1136\/emj.20.2.164","article-title":"Designing a research project: randomised controlled trials and their principles.","volume":"20","author":"J Kendall","year":"2003","journal-title":"Emerg. Med. J."},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1716-1716","DOI":"10.1111\/1471-0528.15199","article-title":"Randomised controlled trials \u2013 the gold standard for effectiveness research.","volume":"125","author":"E Hariton","year":"2018","journal-title":"BJOG Int. J. Obstet. Gynaecol."},{"key":"ref5","doi-asserted-by":"publisher","first-page":"201","DOI":"10.1136\/bmj.316.7126.201","article-title":"Understanding controlled trials. Why are randomised controlled trials important?.","volume":"316","author":"B Sibbald","year":"1998","journal-title":"BMJ."},{"key":"ref6","doi-asserted-by":"publisher","first-page":"dyw314-dyw1886","DOI":"10.1093\/ije\/dyw314","article-title":"Triangulation in aetiological epidemiology.","volume":"45","author":"D Lawlor","year":"2016","journal-title":"Int. J. Epidemiol."},{"key":"ref7","doi-asserted-by":"publisher","first-page":"1182-1188","DOI":"10.1161\/HYPERTENSIONAHA.113.02734","article-title":"Clinical effect of naturally random allocation to lower systolic blood pressure beginning before the development of hypertension.","volume":"63","author":"B Ference","year":"2014","journal-title":"Hypertension."},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1101\/2024.09.20.24314046","article-title":"A quantitative approach to evidence triangulation: development of a framework to address rigour and relevance.","author":"C Shapland","year":"2024"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"e1002828","DOI":"10.1371\/journal.pmed.1002828","article-title":"Association of maternal circulating 25(OH) D and calcium with birth weight: A mendelian randomisation analysis.","volume":"16","author":"W Thompson","year":"2019","journal-title":"PLoS Med."},{"key":"ref11","doi-asserted-by":"publisher","first-page":"240-243","DOI":"10.3163\/1536-5050.104.3.014","article-title":"De-duplication of database search results for systematic reviews in EndNote.","volume":"104","author":"W Bramer","year":"2016","journal-title":"J. Med. Libr. Assoc."},{"key":"ref12","doi-asserted-by":"publisher","first-page":"1972-1995","DOI":"10.1093\/ije\/dyz272","article-title":"Evidence of detrimental effects of prenatal alcohol exposure on offspring birthweight and neurodevelopment from a systematic review of quasi-experimental studies.","volume":"49","author":"L Mamluk","year":"2021","journal-title":"Int. J. Epidemiol."},{"key":"ref13","doi-asserted-by":"publisher","first-page":"108602","DOI":"10.1016\/j.envint.2024.108602","article-title":"A tool to assess risk of bias in non-randomized follow-up studies of exposure effects (ROBINS-E).","volume":"186","author":"J Higgins","year":"2024","journal-title":"Environ. Int."},{"key":"ref14","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.n2233","article-title":"Strengthening the reporting of observational studies in epidemiology using mendelian randomisation (STROBE-MR): explanation and elaboration.","volume":"n2233","author":"V Skrivankova","year":"2021","journal-title":"BMJ."},{"key":"ref15","doi-asserted-by":"publisher","first-page":"55-61","DOI":"10.1002\/jrsm.1411","article-title":"Risk-of-bias VISualization (robvis): An R package and Shiny web app for visualizing risk-of-bias assessments.","volume":"12","author":"L McGuinness","year":"2021","journal-title":"Res. Synth. Methods."},{"key":"ref16","doi-asserted-by":"publisher","first-page":"101484","DOI":"10.1016\/j.cegh.2023.101484","article-title":"Introduction to the GRADE tool for rating certainty in evidence and recommendations.","volume":"25","author":"M Prasad","year":"2024","journal-title":"Clinical Epidemiology and Global Health."},{"key":"ref17","doi-asserted-by":"publisher","DOI":"10.18637\/jss.v036.i03","article-title":"Conducting meta-analyses in R with the metafor package.","volume":"36","author":"W Viechtbauer","year":"2010","journal-title":"J. Stat. Softw."},{"key":"ref18","article-title":"The effect of genetically-predicted adulthood body mass index on blood pressure traits: a systematic review and meta-analysis of Mendelian randomization studies.","author":"W Gatua","year":"2026","journal-title":"Prospero."},{"key":"ref19","doi-asserted-by":"crossref","DOI":"10.1186\/2046-4053-4-1","article-title":"Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement.","author":"D Moher","year":"2015"},{"key":"ref20","doi-asserted-by":"publisher","DOI":"10.5281\/zenodo.19063218","article-title":"PRISMA-P 2015 Checklist \u2013 Supplementary File for The effect of genetically predicted higher adulthood body mass index on blood pressure traits: A protocol for a systematic review and meta-analysis of Mendelian randomisation studies.","author":"W Gatua","year":"2026"}],"container-title":["Wellcome Open Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/11-250\/v1\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/11-250\/v1\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/11-250\/v1\/iparadigms","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T10:39:08Z","timestamp":1785321548000},"score":1,"resource":{"primary":{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/11-250\/v1"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,30]]},"references-count":19,"URL":"https:\/\/doi.org\/10.12688\/wellcomeopenres.26288.1","relation":{"has-review":[{"id-type":"doi","id":"10.21956\/wellcomeopenres.28950.r155372","asserted-by":"subject"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.28950.r157764","asserted-by":"subject"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.28950.r157764","asserted-by":"object"},{"id-type":"doi","id":"10.21956\/wellcomeopenres.28950.r155372","asserted-by":"object"}]},"ISSN":["2398-502X"],"issn-type":[{"value":"2398-502X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,30]]},"assertion":[{"value":"Indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/11-250\/v1#article-reports","order":0,"name":"referee-status","label":"Referee status","group":{"name":"current-referee-status","label":"Current Referee Status"}},{"value":"10.21956\/wellcomeopenres.28950.r157764, Amand Floriaan Schmidt, University College London, London, 25 Jun 2026, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/11-250\/v1#referee-response-157764","order":0,"name":"referee-response-157764","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.21956\/wellcomeopenres.28950.r155372, Sander W. van der Laan, Department of Genome Sciences, University of Virginia (Ringgold ID: 2358), Charlottesville, Virginia, 29 Jul 2026, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/11-250\/v1#referee-response-155372","order":1,"name":"referee-response-155372","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"This work was supported by Wellcome [218495\/Z\/19\/Z]; the medical research council (MRC) [MC_UU_00032\/3, MC_UU_00032\/5]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.","order":2,"name":"grant-information","label":"Grant Information"},{"value":"This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.","order":0,"name":"copyright-info","label":"Copyright"}]}}