Diabetes and ENG1 Article by Doctor Kenneth Prudhoe Club de Mar Medical Centre Palma de Mallorca

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"DOCTOR AT SEA" a monthly Column in The Islander Magazine

Diabetes and ENG1

Top of the list of anxious email queries which I receive from seafarers, mainly yachties, must be the employment implications of diabetes. The job implications used to be so inflexible for insulin-dependent diabetes that major anxiety is understandable and, whilst the situation has eased since January this year, it is still a significant hurdle to working at sea. The UK Maritime and Coastguard Agency overhauled their guidelines to MCA doctors last year and introduced the revisions in January and I would like to pick up some of these revisions from time to time over the next few months.

Insulin is a hormone secreted by the pancreas in the abdomen and it enables glucose to be used as fuel for the body. Without insulin, or with inadequate insulin, the blood glucose rises and leaks into the urine and then pulls more water through the kidneys by osmosis which leads to frequent urination, thirst and dehydration. The rising blood glucose leads to mental confusion, unconsciousness and death.

Diabetes presents in two main forms but there may be overlap between them:

- Type 1, normally but not always in childhood. This form is associated with a lack of insulin production and rapidly progresses to death unless treated with injected insulin – the isolation of insulin at the University of Toronto in 1921 must be one of the medical landmarks of the last century but living with injectable insulin is not the same as living with one’s own insulin quietly secreted without a second’s thought. It is the accidental risk of insulin overdose and a life-threatening drop in blood glucose (hypoglycaemia) that severely restricts the potential for seafaring.

- Type 2, normally diagnosed in middle age and associated with obesity. This can creep up gradually and was often not diagnosed before the days of population screening (glucose in the urine is the giveaway). It progresses much slower than Type 1 and can respond to diet and then tablets before resorting to insulin if all else fails and then the same concerns arise as in Type 1 diabetes.

Diabetes is not just about insulin and glucose and insulin overdose.

It can cause large blood vessel disease increasing the risk of heart disease and stroke and small vessel disease producing retinal eye disease, numbness, kidney failure, poor wound healing and higher incidence of skin infections. These longer-term complications clearly have fitness implications but the small vessel problems are chronic and gradual and can be assessed by examination of the visual acuity, sensation in the various limbs, abnormalities in the urine testing or chronic skin ulceration and infection. The large vessel complications of heart attack or stroke are sudden and potentially devastating with obvious immediate implications for fitness for seafaring – heart attack in particular and heart disease in general is worth a month all to itself.

The acute worry with diabetes is the potentially fatal drop in blood glucose caused by a relative overdose of injected insulin – the drop in blood glucose (hypoglycaemia) produces warning signs such as sweating, palpitations, blunted awareness and confusion, even aggression, before loss of consciousness then, if untreated, death. This imbalance can occur so easily – a physically busy day increases the normal uptake of glucose – a bout of seasickness or tummy upset with vomiting can lead to inadequate intake. It is not difficult to envisage the nightmare of a physically demanding sailing emergency with no time for food, and possibly superimposed vomiting, to understand why insulin-dependent diabetes is not consistent with unrestricted seafaring.

Under the current guidelines, any recently diagnosed diabetic (Type 1 or Type 2) is deemed temporarily unfit until investigated and stabilised. If control is achieved with diet or oral medication then an unrestricted ENG1 can be issued but doubts about control, especially if needing oral medication, can lead to earlier review and restrictions on duties or distances from safe haven.

Treatment with insulin, whether Type1 or advanced Type 2, restricts to near coastal duties with no lone watchkeeping or work at heights and is conditional on informing the captain/responsible person and carrying the antidote to insulin overdose (oral glucose or glucagon injection). It is also necessary to demonstrate good control and to provide annual specialist reports. Fitness in distant waters is restricted to vessels with ship’s doctor.

If control or documentation is imperfect, the ENG1 is restricted to the next assessment deemed appropriate and on work very close to shore and probably returning to shore daily and not sleeping onboard overnight. In all cases of insulin-dependent diabetes, there needs to be full awareness of impending hypoglycaemic attacks, with no reported or observed episodes in the last year, before issuing any degree of fitness certificate.

So there is some scope for diabetics to work at sea but there is plenty of scope for all manner of diabetic guests to be on board. Diabetes is an important component of the MCA Medical Care Onboard Ship Course which is aimed at Captains and persons responsible for medical care and which needs updating at least every five years. We are starting up our monthly MCA medical courses from 13 September after the summer break.

Dr Ken Prudhoe, MCA Approved Doctor, can be contacted at Club de Mar Medical Centre, Palma de Mallorca. Tel: (+ 34) 639 949 125.