’Can I still scuba dive with diabetes?’

At one time the answer would probably have been no, but nowadays it’s quite possible although, as DR ROSIE STOKES of DDRC Healthcare explains, there are criteria to be met

What is diabetes?

Diabetes mellitus is a chronic condition in which the body is unable to regulate sugar levels in the blood, causing them to become too high (hyperglycaemia). Insulin, produced by the pancreas, is the hormone in the body that controls this process. 

This hormonal regulation can be disrupted in different ways, and this is what distinguishes the different types of diabetes.

TYPE 1 DIABETES: This generally presents in younger patients, with the symptoms of hyperglycaemia developing over days or weeks. The cells that produce insulin are destroyed by the immune system requiring patients to have daily insulin injections for the rest of their life.

TYPE 2 DIABETES: This accounts for 90% of diabetes in adults and develops over months to years. Either the pancreatic cells do not produce enough insulin, or the body becomes resistant to the effects of insulin. It is associated with obesity and a sedentary lifestyle and can sometimes be controlled by healthy eating and exercise alone. As it progresses, it can be treated with tablets.

If diabetes is not controlled, people can become dehydrated and unwell very quickly. Symptoms of hyperglycaemia include thirst, fatigue, altered vision, weight loss, frequent urination and poorly healing wounds. 

Over a longer period, it can cause progressive permanent damage to nerves, blood vessels, kidneys and eyes, leading to disability and early death. For this reason, diabetic patients have their sugars closely monitored and have regular check-ups.

Can I dive with diabetes?

Historically, diabetics were advised to stop diving all together. Now, however, divers who are keen to continue may be allowed to do so as long as certain criteria are met, and the safety issues are considered:

• The diver must be over 18

• An annual diving medical must be undertaken

• The diver must have no complications from their diabetes

• They must not have been hospitalised for any reason in the past year in relation to their

diabetes

• They must have a BMI <34.9 (ideally <29.9).

HYPOGLYCAEMIA: Certain medications that help reduce blood sugar can drop the level too low and cause symptoms such as dizziness, anxiety, weakness, seizures or coma, which could be fatal under water. 

Hypoglycaemia can be exacerbated by the exertion of diving, stress or cold water. Therefore it is essential that divers have had no hypoglycaemic episodes in the past year prior to considering diving. 

It is important that the diver has a glucometer to monitor their sugar level pre- and post-dive, and that they are diving with a buddy who is familiar with how it works and how to treat hypoglycaemia. 

It is recommended that a diabetic diver carries a tube of glucose paste (that can be given under water if needed), snacks or oral glucose tablets and an intramuscular injection of glucagon that can be given in an emergency.

LONG-TERM COMPLICATIONS: All diabetics will have a blood test called a HbA1c that gives an indication of their blood sugar control over the past three months. For divers, this needs to be <70mmol/mol at a minimum, although the better the HbA1c, the less the risk of diabetic complications that might interfere with diving and safety under water. 

Having poorly controlled diabetes over many years can lead to damage in different areas of the body, including kidneys, eyes, blood vessels and nervous system, all of which could compromise your safety under water.

What is involved in the dive medical assessment?

At the annual medical, the doctor will discuss with you how well controlled your diabetes has been in the past year. You will have a thorough examination, including a neurological examination, a check for changes to the blood vessels in the back of the eyes and a check of your urine for protein that could be a sign of kidney damage. 

They will also check for signs of heart damage that might indicate risk of heart attack and an increased risk of immersion pulmonary oedema (IPO).

If there is any sign of damage to your body from your diabetes, you should not be diving, because the risk of having an accident under water is much greater, and your body would not be able to recover as well if something did happen.

The key to continue diving is to keep your diabetes well controlled. Your GP and diabetes specialist nurse will be able to help you with that.

Also on Divernet: The making of the biometric diver