Exercise as it relates to Disease/Exercise and prevention of type II diabetes

Prevalence
Type II diabetes is a disease that affects the metabolic system of the human body. Type II diabetes is the most common form of diabetes affecting 85-90% of people who have diabetes. In 2014, there were approximately 981 000 people in Australia living with type II diabetes and this number is projected to increase as more Australians continue to gain weight and live poor lifestyles. In people with type II diabetes their pancreas either cannot produce enough usable insulin or the insulin it does produce cannot be used properly by the body. Insulin is an important hormone, its role in the body is to help regulate glucose levels in the blood as it induces cells to express glucose channels to uptake glucose from the blood into the cell.

How we get it
There is no single cause of type II diabetes, however both genetics and environmental factors increase the risk of getting type II diabetes. In people who have a genetic predisposition of diabetes, there risk of getting type II diabetes is greatly increased if the individual:
 * Is overweight or obese,
 * Has high blood pressure,
 * Has low physical activity levels, and
 * Consumes a poor diet regularly.

Who is at risk
Screening usually occurs in people over the age of 40 by their GP as a way of monitoring potential cases however, these particular population groups are at higher risk of getting type II diabetes:
 * Those with family history
 * Over age 55
 * Are overweight or obese and have high blood pressure and known heart problems
 * Over 35 and have an Aboriginal or Torres Strait Islander background
 * Over 35 and have a Pacific Island, Chinese or Indian background and,
 * Women who have had gestational diabetes.

How we manage it
As type II diabetes is also known as “lifestyle” diabetes, the risk is lowered in people who have a stable healthy weight, manage blood pressure, exercise regularly and avoid foods high in fats and salts.

How exercise helps prevention
Exercise is an important tool in the management and prevention of type II diabetes without the reliance of insulin. Exercise is a planned or structured activity with the aim of developing better cardiovascular and metabolic control. The benefits of exercising if you have diabetes include; increases in insulin sensitivity, glycaemic control, increased aerobic capacity and weight loss. The more intense the aerobic exercise the better the results in glycaemic control and insulin sensitivity. The effect of resistance training is a relatively new area of study and there has been mixed results with some indicating improvements while others did not show significant changes.

One way that exercise helps with improving blood glucose levels is by increasing the uptake of glucose from the blood into the muscle cell using the GLUT-4 transporter. The GLUT-4 transporter is moved from the centre of the cell to the outer cell membrane during exercise. This shift of GLUT 4 is independent of insulin and as a result the number of this transporter increases by nearly 4 times as much compared to levels before exercise. This increase in GLUT 4 transporters will help improve insulin sensitivity in the body, with the effect lasting anywhere from 24 to 72 hours post exercise which is why it is recommended to not have more than 2 consecutive days off exercising.

Glycated haemoglobin or HbA1C is the amount haemoglobin that has glucose attached to it. The more glucose in the blood stream the higher the HbA1C levels a person will have. A HbA1C test gives you an average blood glucose reading over the lifespan of haemoglobin. This test is the gold standard in measuring glycaemic control and gives a longer term picture of blood glucose levels rather than the levels at a particular time like with a normal blood glucose test. A person without diabetes will have a HbA1C reading of approximately 5% whilst those with type II diabetes should aim to keep theirs around 6.5%. Several studies have shown decreases in the HbA1C levels in people with type II diabetes after exercise,. Both aerobic and resistance training, have shown a decrease in HbA1C levels after only a 10 week program. However, it is the resistance training that has a greater decrease compared to aerobic exercise. One study showed a decrease of nearly 20% in HbA1C levels in resistance exercise compared to only an 8% decrease in aerobic exercise.

Recommendations
A combination of resistance and aerobic exercise is best.

Conclusion
Type II diabetes is a common disease affecting thousands of people, although there is a large genetic influence in contracting diabetes, it can be prevented or managed with lifestyle changes. Exercise is an important tool in preventing and managing type II diabetes. It is recommended that both aerobic and resistance training be undertaken to achieve maximum results.