The Diabetes Epidemic : What is Diabetes and why is it a problem? [article]

Diabetes is a disease that has reached epidemic proportions both internationally and within New Zealand. It is the leading cause of blindness, kidney failure and lower limb amputations in the world.  So what is this horrible disease? How do we get it? And let’s face it – we are personal trainers not physiologists. How much do we really need to understand about the disease to train our Diabetic clients effectively?

Normal Glucose Metabolism

To understand Diabetes we first need to recap how glucose (blood sugar) is normally regulated in our bodies. Insulin and glucagon are the two hormones that keep our glucose levels controlled.

Insulin is released from the beta cells on our pancreas when glucose levels are high. Insulin helps move glucose from the blood stream into our muscles and liver, and stores any extra glucose as fat. Glucose cannot enter your body’s cells from the bloodstream by itself, so insulin acts like a ‘key’. Once released into the blood, insulin binds to insulin receptors (the ‘keyholes’) located on the cell walls, ‘unlocking’ the cell and allowing the glucose to enter. This glucose can either be used immediately as energy or stored as glycogen or fat for future use.

 

When blood glucose levels are low, insulin secretion is decreased, and the hormone glucagon is released from the pancreas instead. Glucagon works to break down the glycogen stores in the liver. This glucose is then released back into the bloodstream to raise the low glucose levels, meaning there is a constant supply of energy for the brain and the body.  Glucose is the brains primary source of fuel, so a decrease in supply can impair brain function and put an individual’s life at risk.

The body constantly performs a delicate balancing act to keep our glucose levels in a reasonably narrow range (4-8mmol/L).  If glucose levels get too low (hypoglycaemia) there is a serious risk of coma, or even death. On the flip side, when glucose levels get too high, the symptoms of Diabetes begin to appear.

So what actually happens when you have Diabetes?

Diabetes is a disease characterised by high glucose levels in the blood (hyperglycaemia). This is due to someone either not being able to use the insulin their body produces, or because of a problem with insulin production and/or release.  Once blood glucose levels rise above a certain level and the symptoms of Diabetes appear (feeling tired, excessive urination and constantly feeling thirsty), Diabetes is diagnosed.

Depending on the type of Diabetes diagnosed, a mixture of diet, exercise and medication will be prescribed for the individual. Diabetes cannot be ‘cured’, so the aim is to manage the disease by bringing glucose levels down into the normal range, and keeping them there!

What’s so bad about high glucose levels?

If a Diabetic can’t keep their glucose levels in a safe range, they could develop a number of long term health complications. High glucose levels make blood thicker, which can cause problems with high blood pressure - imagine golden syrup flowing through your blood vessels!  This can cause damage to the smaller blood vessels in your body – for example in your eyes (leading to blindness), toes (leading to amputations) and kidneys (leading to kidney failure). Thick blood can also damage the blood vessels supplying your nervous system, causing loss of sensation and numbness, especially in your extremities like your feet.  Maintaining healthy glucose levels over the long term will prevent or delay the onset of Diabetes complications.

To sum it up, Diabetes is bad news, and due to our over-indulgent and inactive lifestyle, it is more and more common these days. The following articles in this series will examine the two main types of Diabetes – Type 1 and Type 2 in more detail, and discuss both the challenges and the benefits of training people with Diabetes.