{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T17:10:07Z","timestamp":1789233007797,"version":"build-2803163510"},"reference-count":14,"publisher":"BMJ","issue":"3","license":[{"start":{"date-parts":[[2025,9,1]],"date-time":"2025-09-01T00:00:00Z","timestamp":1756684800000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open Sport Exerc Med"],"accepted":{"date-parts":[[2025,8,1]]},"published-print":{"date-parts":[[2025,9]]},"abstract":"<jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>The use of continuous glucose monitors (CGM) in scuba diving for patients with type 1 diabetes (T1DM) shows potential but faces challenges related to accuracy. Previous research has highlighted the poor accuracy of the Dexcom G7 (DG7) in repetitive diving contexts. This study investigates the impact of calibration on the accuracy of DG7, providing valuable insights for patients and clinicians.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Materials and methods<\/jats:title>\n                  <jats:p>In August 2024, \u2018Diabete Sommerso\u2019 organised a 4-day diving cruise around Elba Island (Italy) with 15 participants, including individuals with T1DM. Each participant with diabetes wore two DG7 sensors (one on the arm and one on the abdomen), calibrated daily and compared the results to capillary glucose (Beurer GL50Evo as the reference). Accuracy was assessed using mean absolute relative difference (MARD)\/median ARD, Food and Drug Administration (FDA) integrated continuous glucose monitoring (iCGM) criteria and Surveillance Error Grid (SEG) analysis. Hypoglycaemia detection and trends were also evaluated.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Eight participants with T1DM completed the study using 16 DG7 sensors with no detachments or skin reactions. Analysis of 765 sensor-capillary glucose pairs during 68 dives showed an overall MARD of 13.7%, with arm sensors (11% MARD) outperforming abdomen sensors (16%, p=0.0001). SEG analysis revealed that more than 97% of readings fell within the no-risk zone; however, the FDA\u2019s iCGM criteria for non-adjunctive use were not met.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Calibration improved the accuracy of DG7 in repetitive diving for patients with T1DM. However, capillary glucose checks remain essential, as non-adjunctive criteria were not met.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjsem-2025-002809","type":"journal-article","created":{"date-parts":[[2025,9,1]],"date-time":"2025-09-01T16:15:20Z","timestamp":1756743320000},"page":"e002809","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":3,"title":["Calibrating Dexcom G7 improves its performance in the context of repetitive recreational scuba diving in people with type 1 diabetes"],"prefix":"10.1136","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0483-7126","authenticated-orcid":false,"given":"Elena","family":"Gamarra","sequence":"first","affiliation":[{"name":"Servizio di Endocrinologia e Diabetologia, Repubblica e Cantone Ticino Ente Ospedaliero Cantonale, Bellinzona, TI, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giovanni","family":"Careddu","sequence":"additional","affiliation":[{"name":"Endocrinologia Diabetologia e Malattie del Ricambio, ASL 3 Genovese, Genoa, Liguria, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea","family":"Fazi","sequence":"additional","affiliation":[{"name":"Agenzia Sanitaria Regionale, Ancona, Marche, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Valentina","family":"Turra","sequence":"additional","affiliation":[{"name":"ASST Spedali Civili di Brescia, ASST Spedali Civili di Brescia, Brescia, Lombardy, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ambra","family":"Morelli","sequence":"additional","affiliation":[{"name":"Clinica San Carlo, Paderno Dugnano, Lombardy, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pierpaolo","family":"Trimboli","sequence":"additional","affiliation":[{"name":"Servizio di Endocrinologia e Diabetologia, Repubblica e Cantone Ticino Ente Ospedaliero Cantonale, Bellinzona, TI, Switzerland"},{"name":"Facolt\u00e0 di Scienze Biomediche, USI, Lugano, TI, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,9,1]]},"reference":[{"key":"2025090109150932000_11.3.e002809.1","first-page":"1074","article-title":"Scuba Diving and Diabetes","volume":"18","author":"Kruger","year":"1995","journal-title":"Practical Guidelines Diab Care"},{"key":"2025090109150932000_11.3.e002809.2","unstructured":"Winsett RP , Kendrick WW , Prosterman S , et al . Diving safely with diabetes. In: Perry M , ed. Proceedings of the 1992 International Conference on underwater education; 1992:231\u20134."},{"key":"2025090109150932000_11.3.e002809.3","doi-asserted-by":"crossref","first-page":"135","DOI":"10.28920\/dhm50.2.135-143","article-title":"Recreational diving in persons with type 1 and type 2 diabetes: Advancing capabilities and recommendations","volume":"50","author":"Jendle","year":"2020","journal-title":"Diving Hyperb Med"},{"key":"2025090109150932000_11.3.e002809.4","doi-asserted-by":"publisher","DOI":"10.1177\/193229680800200505"},{"key":"2025090109150932000_11.3.e002809.5","doi-asserted-by":"publisher","DOI":"10.1089\/dia.2009.0017"},{"key":"2025090109150932000_11.3.e002809.6","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/j.diabet.2008.08.007","article-title":"Safety of recreational scuba diving in type 1 diabetic patients: The Deep Monitoring programme","volume":"35","author":"Bonomo","year":"2009","journal-title":"Diabetes & Metabolism"},{"key":"2025090109150932000_11.3.e002809.7","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1177\/1932296819826584","article-title":"Continuous Glucose Monitoring Diving and Diabetes: An Update of the Swedish Recommendations","volume":"14","author":"Jendle","year":"2020","journal-title":"J Diabetes Sci Technol"},{"key":"2025090109150932000_11.3.e002809.8","first-page":"265","article-title":"Continuous real-time monitoring and recording of glycemia during scuba diving: pilot study","volume":"43","author":"Pieri","year":"2016","journal-title":"Undersea Hyperb Med"},{"key":"2025090109150932000_11.3.e002809.9","doi-asserted-by":"crossref","unstructured":"Herold P , Weh D . Performance of continuous glucose monitoring systems under hyperbaric conditions an exploratory study to increase diabetic divers\u2019 safety. Medicine and Pharmacology [Preprint] 2023. doi:10.20944\/preprints202307.0268.v1","DOI":"10.20944\/preprints202307.0268.v1"},{"key":"2025090109150932000_11.3.e002809.10","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1089\/dia.2024.0126","article-title":"Continuous Glucose Monitoring and Recreational Scuba Diving in Type 1 Diabetes: Head-to-Head Comparison Between Free Style Libre 3 and Dexcom G7 Performance","volume":"26","author":"Gamarra","year":"2024","journal-title":"Diabetes Technol Ther"},{"key":"2025090109150932000_11.3.e002809.11","doi-asserted-by":"publisher","DOI":"10.1089\/dia.2014.0272"},{"key":"2025090109150932000_11.3.e002809.12","unstructured":"Available: https:\/\/www.accessdata.fda.gov\/scripts\/cdrh\/cfdocs\/cfcfr\/cfrsearch.cfm?fr=862.1355"},{"key":"2025090109150932000_11.3.e002809.13","doi-asserted-by":"crossref","unstructured":"Bonomo MA , Careddu G , Corigliano G , et al . La persona con diabete tipo 1 e le immersion subacquee. Il Diabete Online, organo ufficiale della Societ\u00e0 Italiana di Diabetologia. 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