The Seafarers' Continuous Glucose Monitoring Systems Study

NCT07251257 | Recruiting

• 2 other identifiers: FHMS 23-24 062 EGA/ERM ID 2469#1716
• Study Type: observational
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

People with diabetes sometimes consider that they are subjected to unfair discrimination in the occupational or work environment. These include safety-critical activities, such as operating machinery and driving 1-3. Some occupations preclude the use of medications that lower blood glucose, particularly insulin. Safety regulators, occupational health physicians and national organisations frequently have to balance the competing priorities of individual rights against public safety. Modern treatment, with advances in insulin therapy and glucose monitoring, combined with rigorous clinical assessment and review, has allowed stereotypical attitudes to be challenged and advocated individual assessment with respect to safety criteria. Along with the UK Driving and Vehicle Licensing Agency (DVLA) and Civil Aviation Authority (CAA), the Maritime and Coastguard Agency (MCA) have accepted that insulin-treated diabetes should not be an absolute contra-indication to partaking in these occupational activities4. However, as the Disability Discrimination Act (1995) recognises that there may be specific employment-related hazards, fitness to work should be assessed on an individual basis. Therefore, each of these transport agencies has established regulatory standards for their respective domains, with the priority of minimising hypoglycaemic incapacitation risks. The CAA, for example, has worked alongside other European countries to use the ARA.MED.330 protocol and require medically certified pilots to check their blood glucose levels regularly before and during flights. In 2010, the UK CAA's expert committee reviewed the knowledge and policies concerning flying and it was decided that Continuous Glucose Monitoring (CGM) systems were not accurate enough and instead used finger prick-blood glucose monitoring (SMBG) as the gold standard. Since then, the protocol has been successfully implemented and there are current works in progress that demonstrate sufficient accuracy in modern CGMs as a viable alternative to SMBG. Similarly, the guidelines devised by the MCA, Approved Doctor's Manual (ADM), place a great emphasis on the type and treatment of diabetes, with the primary concern being risks of cognitive impairment or incapacitation5. Emphasis is placed on the need for able glycaemic control and "full awareness of impending hypos, with no reported or observed significant hypoglycaemic episodes in the last year". The guidance stipulates that certification may be restricted on individuals pending their medication side effects, compliance, and vascular risk factor control. Previous regulations prevented seafaring individuals such as insulin-treated seafarers from partaking in lone watchkeeping/lone-working roles and restricted them to near-coastal duties (150-200 nautical miles) (Appendix 1). Current regulations allows for exemptions for certain vessels, provided that the seafarer's diabetes control remains stable and is subject to blood glucose monitoring. Regardless, an approved medical assessor is needed to conduct these specific medical assessments in line with the statutory standards in MSN 1886 and guidance in the ADM. All seafarers who are insulin-dependent and licenced to undertake seafaring in the UK will be invited to participate in this study.

Conditions

Insulin Dependent Diabetes

Keywords

insulin dependent diabetes; Continuous glucose monitoring; Seafarers; Fishers

Outcome Measures

Primary Outcomes (1)

• To evaluate the glucose monitoring of CGM systems in the context of their usual occupational activities and establish its feasibility as a routine glucose monitoring device while at sea.

  Evaluation of the glucose monitoring of CGM systems in the context of the seafarers' usual occupational activities and establish its feasibility as a routine glucose monitoring device while at sea. Glucose measurements will be based on a traffic light system, with \<5 mmol/L coded as red, 5-20 mmol/L as green, and \>20 mmol/L coded as red as per our maritime protocol.

  12 months

Secondary Outcomes (4)

• Glucose variability while working or on rest period at sea

  12 months

• Time in and out of range while seafaring (targets used as other clinical trials)

  12 months

• Feasibility and safety assessment of using CGM systems during seafaring activities

  12 months

• Questionnaire data an overview of participants' preferences

  12 months

Study Arms (1)

Seafarers wearing CGM device

Fifty seafarers will be recruited to participate in a one-year study utilizing the Dexcom G7 Continuous Glucose Monitoring (CGM) system. Participants will also be enrolled in the web-based Fishers Watch application, which will deliver daily reminders via text message prompting them to note on their activities both at sea and on land.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Seafarers requiring insulin replacement therapy, and holding a valid ML5 or ENG1 certificate

You may qualify if:

• Any ethnicity
• Seafarers requiring insulin replacement therapy,
• Holding a valid ML5 or ENG1 certificate
• Able and willing to wear a Continuous Glucose Monitoring system (GCMS) for 12 months
• Able and willing to document out of range glucose values and activities in Fishers Watch App a while at sea

You may not qualify if:

• Outside of the stated age range.
• Not able to use using a CGM glucose monitoring system for monitoring the glucose levels.

Sponsors & Collaborators

• The UK Maritime and Coastguard Agency: collaborator
• University of Surrey: lead

Study Sites (1)

University of Surrey FHMS Nutritional Sciences

Guildford, Surrey, GU2 7WG, United Kingdom

RECRUITING

Related Publications (4)

• Garden GL, Hine JL, Mitchell SJ, Hutchison EJ, Gaffney TP, Hofmann V, Frier BM, Shaw KM, Heller SR, Koehler G, Roberts GA, Russell-Jones DL. An Evaluation of the Safety of Pilots With Insulin-Treated Diabetes in Europe Flying Commercial and Noncommercial Aircraft. Diabetes Care. 2020 Dec;43(12):2923-2929. doi: 10.2337/dc20-0277. Epub 2020 Jun 25.

  PMID: 32586987 RESULT

• Ehrmann D, Heinemann L, Freckmann G, Waldenmaier D, Faber-Heinemann G, Hermanns N. The Effects and Effect Sizes of Real-Time Continuous Glucose Monitoring on Patient-Reported Outcomes: A Secondary Analysis of the HypoDE Study. Diabetes Technol Ther. 2019 Feb;21(2):86-93. doi: 10.1089/dia.2018.0332. Epub 2019 Jan 7.

  PMID: 30615479 RESULT

• Wadwa RP, Laffel LM, Shah VN, Garg SK. Accuracy of a Factory-Calibrated, Real-Time Continuous Glucose Monitoring System During 10 Days of Use in Youth and Adults with Diabetes. Diabetes Technol Ther. 2018 Jun;20(6):395-402. doi: 10.1089/dia.2018.0150. Epub 2018 Jun 14.

  PMID: 29901421 RESULT

• Shah VN, Laffel LM, Wadwa RP, Garg SK. Performance of a Factory-Calibrated Real-Time Continuous Glucose Monitoring System Utilizing an Automated Sensor Applicator. Diabetes Technol Ther. 2018 Jun;20(6):428-433. doi: 10.1089/dia.2018.0143.

  PMID: 29923775 RESULT

Related Links

• Maritime \& Coastguard Agency. Approved Doctor's Manual Seafarer Medical Examinations. 2020;1886.
• Maritime \& Coastguard Agency. MSN 1883 (F) Amendment 5 Work in Fishing Convention (No. 188): Medical examination and certification for fishers \[Internet\]. 2024.

MeSH Terms

Conditions

Diabetes Mellitus, Type 1

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases

Study Officials

• David L Russell-Jones, MD

  University of Surrey

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Fariba Shojaee-Moradie, Ph.D.

CONTACT

+441483464049; f.shojaee-moradie@surrey.ac.uk

David L. Russell-Jones, M.D. FRCP.

CONTACT

+441483464049; davidrussell-jones@nhs.net

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Target Duration: 12 Months
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 18, 2025
• First Posted: November 26, 2025
• Study Start: November 20, 2025
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): April 1, 2027
• Last Updated: January 6, 2026

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)