Abstract
Diabetes mellitus, a metabolic disorder characterized by hyperglycaemia, is a disease that has been rapidly increasing worldwide. According to the fact sheet of the World Health Organization (WHO), there are more than 346 million people worldwide suffering from diabetes which can lead to complications such as atherosclerosis, nephropathy, and retinopathy (WHO, 2011). In 2004, an estimated 3.4 million people died from the consequences of high blood glucose (WHO, 2011). It has been reported that by 2030, about 438 million people worldwide are expected to have diabetes (Donald et al., 2012). In 2010, the prevalence of diabetes mellitus in adults in the United Kingdom and the United States was 7% and 11% respectively (Noble et al., 2011). In Australia, more than 3.5 million Australians have diabetes. Diabetes mellitus in Australia is the cause of a considerable portion of the total burden of diseases, and significant costs. For example, Type 2 diabetes costs Australia $3 billion a year (Australia Diabetes, 2011). Hyperglycaemia can result as a consequence of a deficiency in the release of insulin or result from insulin resistance. Patients with diabetes are classified into two groups; patients having type 1 (insulin-dependent) or type 2 (insulin-independent) diabetes mellitus. Prolonged periods of type 1 or type 2 diabetes mellitus, and thus an extended exposure to hyperglycaemia, can have severe effects on both the macro-and microvasculature. This is as an outcome of disturbances in several metabolic and