September 12, 2016
EASD: U.K. Airline Pilots Fit to Fly With Diabetes
Dr. Spyros Mezitis, Endocrinologist, Clinical Investigator, Lenox Hill Hospital
Commercial airline pilots flying with insulin-controlled diabetes had no incidents of medical incapacitation in more than 18 months of study, researchers reported here.
Of the 26 insulin-treated pilots flying planes under the U.K. flag, a total of 8,897 blood glucose monitoring values had been recorded during 4,900 flight hours with more than 96% of the cockpit glucose monitoring readings indicating pilots with diabetes were in the "Green Zone" for safety, reported Julia Hine, MD, of the Royal Surrey County Hospital in Guildford, England.
In a presentation at the European Association for the Study of Diabetes, Hine said that for short and medium haul flights -- those of less than 6 hours duration -- 96% of 7,829 blood glucose monitoring readings were within the safe range. For long haul flights, 97% of 1,068 readings were within that "green" range.
She reported that 19 readings – 0.2% -- across short and long haul flights combined were in the "red" range and to date, no pilot medical incapacitation due to low or high blood sugar has been reported.
The study was conducted by the medical staff at Royal Surrey County Hospital and the U.K. Civil Aviation Authority (CAA), based at London's Gatwick Airport.
That aviation agency defines the "green zone" as glucose levels between 5-15 mmol/l (90 to 270 mg/dL); "amber" as glucose levels from 4-5 mmol/l (72-90 mg/dL) through 15-20 mmol/l (270-360 mg/dL), and "red" as glucose levels of less than 4 mmol/l (less than 72 mg/dL) or greater than 20 mmol/l (360 mg/mL).
U.S. pilots with a diagnosis of diabetes are not permitted to pilot commercial airlines.
In 2012, the U.K. became the second nation, after Canada, to issue insulin-treated individuals with Class 1 Medical Certificates for Commercial Pilot Licences. Ireland has since joined the list that allows insulin-treated diabetics to pilot airliners. The U.K. now has the largest cohort of insulin-treated pilots, and, Hine said, is leading the way in Europe and beyond to create and maintain employment and leisure opportunities for people with insulin-treated diabetes.
"A growing number of insulin-treated pilots have successfully applied for Commercial Pilots' Licences in the U.K. and most recently Ireland," she reported. "To date, the CAA protocol has [been] shown to work well in the cockpit, with no reported safety concerns, and without deterioration of diabetes control."
She noted that a comprehensive protocol, developed by a panel of medical and aviation experts, governs the medical certification of insulin-treated pilots. Certificated pilots are subject to strict requirements, directly overseen by the U.K. CAA and Irish Aviation Authority medical departments, including pre- and in-flight blood glucose monitoring.
"Regular blood glucose testing in the cockpit ensures that any variability in blood sugar is detected and can be corrected early," Hine noted. "If pilots are unable to test their blood sugar due to operational demands, the protocol dictates that they should consume 15 mg of carbohydrate as a precautionary measure and then test within 30 minutes."
"Normal glucose levels are 70 to 140 mg/dL, and diabetics are well-controlled if their glucose levels range between 80 and 180 mg/dL," commented Spyros Mezitis, MD, PhD, an endocrinology consultant and clinical investigator at Lenox Hill Hospital in New York City. "Most studies have shown few diabetic complications with the 3-month HbA1c average being below 7%.
"Acute diabetic symptoms are usually seen with glucose values above 300 mg/dL and neuroglycopenic symptoms implicating cognitive changes appear below 50 mg/dL," he told MedPage Today. "Considering the aforementioned blood sugar values, the United Kingdom pilot study results are reasonable with insulin-requiring pilots not having any problems with flying when their blood sugar values are in the green range of 90-279 mg/dL.
"It is important to continue monitoring insulin-requiring pilots who are actively flying around the world," Mezitis said.
For the study, with the pilots' consent, files for all insulin-treated, Class 1-certificated pilots were reviewed and data were collected, Hine reported.
The researchers found that at the analysis date, 26 insulin-treated pilots had been issued with Class 1 medical certificates. All were men, with an average age of 41.
The majority (85%) had type 1 diabetes, with an average diabetes duration of 8 years. U.K. commercial pilots who develop diabetes after getting their licence can also apply for a Class 1 Medical certificate under the protocol described for insulin-treated pilots.
Average follow-up duration after license issue in the study was 19.5 months. The average pre-license issue HbA1c was 53.1 mmol/mol (about 7%); the average of the most recent HbA1c was 54.8 mmol/mol, thus showing no significant change (P=0.25), Hine and colleagues reported.
She said the study is continuing. "There are a number of European states that have expressed interest in the program," Hine reported. "The American Diabetes Association's position is that individual assessment of people with diabetes is the appropriate approach to determining whether a person is qualified to perform certain activities."
That association is developing recommendations to share with the U.S. Federal Aviation Administration that would enable the FAA to identify pilots who are at no greater risk for incapacitation than any other pilot, she added.