Miriam E Tucker

September 13, 2016

MUNICH — People with insulin-treated diabetes can be safe air pilots, new data from the United Kingdom indicate.

In 2012, the United Kingdom became only the second country in the world — after Canada — to issue class 1 medical certificates for commercial pilot licenses (CPLs) to people with diabetes who use insulin (or sulfonylureas/glinides) and who are deemed low risk and follow a set protocol for glucose monitoring and adjustments.

Approximately 70 people have been granted such CPLs thus far, and data for 26 of those individuals were presented here at the European Association for the Study of Diabetes (EASD) 2016 Annual Meeting by Dr Julia Hine, Cedar Centre, Royal Surrey County Hospital, Guildford, United Kingdom.

Over an average follow-up of nearly 2 years, more than 95% of glucose readings were in the designated "safe" range of 5 to 15 mmol/mol (90–270 mg/dL), and no episodes of pilot medical incapacitation due to low or high blood sugar were reported.

"The protocol works well in the cockpit, with no reported safety concerns or deterioration in glycemic control. It represents an advance in patient care, allowing insulin-treated patients to safely perform complex occupational duties," Dr Hine said in her presentation.

Asked to comment, session moderator Soffia Gudbjörnsdottir, MD, professor in diabetes and registry studies at the University of Gothenburg, Sweden, told Medscape Medical News, "I think this gives hope for people with type 1 diabetes."

However, she cautioned that because the study was conducted only in men who already had pilot's licenses when they developed diabetes, it might not apply to others. "It's not tested for a 20-year-old treated for diabetes 19 years. That's a different question," she pointed out.

Comprehensive Protocol

Key to the program's success is a comprehensive protocol developed by a panel of medical and aviation experts governing the medical certification of insulin-treated pilots and based on available literature regarding hypoglycemia risks and experience from various transport modalities.

To qualify, pilots had to have normal renal function, no significant retinopathy or neuropathy, good hypoglycemia awareness and understanding, and blood pressure at or below 140/80 mm Hg.

The program, directly overseen by the UK Civil Aviation Authority (CAA) medical department, includes the following elements:

  • Three CAA-specified glucose ranges, indicating levels considered safe ("green") for flying of 5 to 15 mmol/mol (90–270 mg/dL); levels of caution ("amber") with designated corrective actions, 4 to 5 mmol/mol (72–90 mg/dL) for hypoglycemia and 15 to 20 (270–360 mg/dL) mmol/mol for hyperglycemia; and urgent ("red") levels requiring priority action (<4 or >20 mmol/mol [<72 or >360 mg/dL]) ranges.

  • Pilots must test their blood glucose at least 2 hours before flying and at least 1 hour prior for commercial pilots reporting for flight duty and again less than 30 minutes before the flight. If the levels fall into the "red" zone, the pilot can't fly.

  • During flight, those on insulin should test at least once every hour. For those taking sulfonylureas or glinides, they should test at least every 2 hours while flying.

  • Testing is done again within 30 minutes prior to landing, with repeat if approach or landing is unexpectedly delayed.

  • Glucose levels must be tested at any stage if any diabetic symptoms are experienced.

  • If any in-flight level falls into the "red" range, the pilot must hand over the controls to the copilot.

  • Pilots can cut back the testing on formal rest breaks but must restart prior to resuming control of the plane.

  • Clinical surveillance by the CAA every 6 months (or 12 for private pilots).

  • Pilots are permitted to use insulin pumps and continuous glucose monitors as adjuncts, but they are required to carry backup injected insulin supplies and must still perform finger-stick monitoring per protocol. (Currently, CGM use isn't validated at high altitude, Dr Hine noted.)

Nearly All Readings in "Green" Range

The 26 insulin-treated pilots issued class 1 medical certificates were all male, with an average age 41 years. Most (84.6%) had type 1 diabetes, with average duration of 8.1 years.

The average follow-up duration post–license issue was 19.5 months. HbA1c levels didn't change pre– to post–license issue (from 53.1 to 54.8 mmol/mol, or roughly 7% to 7.2%, = .25).

A total of 8897 blood glucose monitoring values were recorded during 4900 flight hours, with a median of 332 per pilot.

For flights shorter than 6 hours, 95.8% of 7829 blood glucose readings were in the "green" range. For flights longer than 6 hours, 96.9% of 1068 readings also fell within "green" parameters.

Just 19 (0.2%) readings were in the "red" ranges, and there were no reports of pilots experiencing medical incapacitation due to hypo- or hyperglycemia.

In an ongoing assessment program, "all pilots are finding the protocol practical and feasible in the cockpit and compatible with safe performance of their other flying duties," Dr Hine reported.

Expanding the Program Elsewhere

Thus far, the program is available only for people who were already licensed pilots before developing insulin-treated diabetes, but the team is collecting safety data for people with preexisting diabetes who are training to become certified pilots in order to satisfy requirements of the European Aviation Safety Agency. The same protocol applies, Dr Hine explained.

She noted that several other European states have expressed interest in the program.

In the United States, the Federal Aviation Administration (FAA) does not allow medical certificates for people who use insulin to operate commercial aircraft, although they can apply for a third-class medical certificate, which allows them to perform private and recreational operations and fly as student pilots, flight instructors, or sport pilots.

The American Diabetes Association (ADA) opposes that "blanket ban" and instead takes the position that individual assessment of people with diabetes is the appropriate approach to determining whether a person is qualified to perform certain activities.

The ADA is currently "developing recommendations to share with the US FAA that would enable the FAA to identify pilots who are at no greater risk for incapacitation than any other pilot," according to the association's position statement.

Dr Gudbjörnsdottir told Medscape Medical News, "I must admit it's really a new thought….You might ask is it a human right to fly an airplane? Perhaps we should think that way and try to do everything we can to [enable patients]. Obviously, it's very important for these persons and we should provide person-centered care. So, you have to say yes to this."

Dr Hine and Dr Gudbjörnsdottir have no relevant financial relationships.

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European Association for the Study of Diabetes (EASD) 2016 Meeting; September 13, 2016; Munich, Germany. Abstract 71.


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