Diabetes developments – by Simon O’Neill

In a regular blog series, Simon O’Neill, Diabetes UK’s Director of Health Intelligence and Professional Liaison, rounds up the latest diabetes news.
This week Simon looks at pilots with diabetes and statins.

Pilots with diabetes

Simon-O'Neill-Director-of-HIn 2012, the UK became the second country, after Canada, to issue Class 1 Medical Certificates for Commercial Pilot Licenses (CPLs) to people with insulin-treated diabetes. Ireland followed suit in 2015. Apparently the UK now has the largest number of insulin-treated pilots, and is leading the way in Europe and beyond to enable people with insulin treated diabetes to undertake flying for both employment and pleasure.

To become a certificated pilot, people have to follow a comprehensive Medical Assessment Protocol, which was developed by a panel of medical and aviation experts. This protocol is directly overseen by the UK Civil Aviation Authority (CAA) and the Irish Aviation Authority (IAA) medical departments and includes pre- and in-flight blood glucose monitoring. These values are classified as “Green” (5-15mmol/l), “Amber” (4-5 and 15-20mmol/l), and “Red” (20mmol/l).

A study presented at this year’s EASD meeting reported on a trial which demonstrated that UK commercial airline pilots with insulin-treated diabetes can fly safely, with almost all of their blood glucose readings at safe levels. Data was collected from all insulin-treated certificated pilots, including age; date of issue of Class 1 Medical Certificate; diabetes type and duration; diabetes management regimen; comorbidities; diabetes complication monitoring; all available HbA1c values pre- and post-license issue; and all flights undertaken with associated blood glucose monitoring values.

The researchers found that 26 insulin-treated pilots had been issued with Class 1 medical certificates. All were male, with an average age of 41 years. The majority (85%) had T1D, with an average diabetes duration of 8 years. Average follow up duration post-license was 19.5 months. The average pre-license issue HbA1c was 53.1mmol/mol (7.0%) while the average of the most recent HbA1c was 54.8mmol/mol (7.1%). This shows that even following this protocol, which allows for a much wider range of ‘normal’ glucose values, there was no deterioration in overall control.

A total of 8,897 blood glucose monitoring values had been recorded during 4,900 flight hours. For short and medium haul flights (under 6 hours), 96% of blood glucose monitoring readings were within the ‘green’ range while for long haul flights (over 6 hours), 97% of readings were within the ‘green’ range. A total of 19 (0.2%) readings across short and long haul flights combined were in the ‘red’ range but none of these had led to pilot incapacitation during a flight.

Other European states are interested in joining the programme, which is a great move forward for individual assessment of fitness to do a role.

Doug Cairns, one of the pilots who worked hard to get this ruling in to place in the UK, also demonstrated that pilots with insulin treated diabetes can’t only fly safely – they can also fly fast. Having already successfully flown around the world with T1D, back in July, he and Karl Beetson, who also has T1D, broke a world record after landing their small, home-made planes in Malta from London in just under 13 hours. By making it from London to Malta between sunrise and sunset, including three refueling stops on the way, the pair set a World Aviation Speed Record, flying the tiny Vans RV8 and Vans RV4.

Statins – the controversy rumbles on

An academic review of the strengths and limitations of non-randomized evidence around statins was published in the Lancet in September. The overall gist of the document was that the benefits of statins have been underestimated and the risks exaggerated. The authors argue that the high levels of statin intolerance (up to 20% of people), which were reported in several papers in the BMJ, are not actually supported by large scale evidence from randomized trials.

The authors of this latest paper suggest that treating 10,000 people for five years with an effective statin regimen would typically cause about five extra cases of myopathy (muscle weakness and pain) of which one might progress to rhabdomyolysis (severe breakdown of muscle), 50 to 100 cases of diabetes, and five to 10 hemorrhagic strokes (bleeding into the brain).

The authors have suggested that the controversy about statin intolerance and myopathy rates have only really emerged in the past two or three years as manufacturers began marketing newer cholesterol-lowering agents, such as PCSK9 inhibitors, for people who have been seen to be unable to use statins. Certain reports, such as that of the European Atherosclerosis Society Consensus Panel, highlighting statin intolerance have been funded by pharma, although there are the usual disclaimers that this funding has in no way influenced the report outcomes.

The authors also point out that any adverse effects of statin use can usually be reversed by stopping statin treatment, whereas the same cannot be said for an adverse event such as a heart attack or stroke.

However, there was immediately a backlash questioning how true the evidence is to a real world situation. Trials are often only carried out on relatively well and younger patients, so may not study groups such as the elderly, and not all studies may be large enough to detect all relevant harms.

Critics of the paper went on to point out that the group publishing the review had received hundreds of millions of pounds in funding from statin manufacturers and that they had not released raw data on the major statin randomized controlled trials for independent scrutiny. They also criticized the fact that most of the trials were industry-sponsored for the purpose of determining the benefits of statins – although this is commonly where most pharmaceutical research comes from.

Both sides of the argument do agree that there is a place for statins – but deciding whether they should be a treatment for all or for a chosen group is not agreed. Of course the impact of these public disagreements leads to front line headlines in the popular press. Apparently more than 200,000 people are estimated to have stopped taking a statin in the six months after the last adverse media coverage, following publication of the disputed research. It is also confusing for medical professionals who are also being given conflicted advice – though perhaps, as most people seem to agree that there is a benefit for more than 80% of the population, perhaps the most pragmatic approach is to start with a stain, monitor closely for any side effects, and change treatment if they occur or if no clinical benefit is seen.

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