Diabetes mellitus, part 1: physiology and complications.

In part 1 of this 2-part article the author discusses the physiology and complications of diabetes mellitus (DM), a chronic and progressive disorder which affects all ages of the population. The number of people diagnosed with diabetes is approximately 1.8 million and an estimated further 1 million are undiagnosed (Department of Health, 2005). In the UK, 1-2% of the population have diabetes and among school children this is approximately 2 in 1000 (Watkins, 1996). There are two main types of diabetes--type 1 and type 2 (Porth, 2005). The aetiology of DM is unknown; however, genetic and environmental factors have been linked to its development. Type 1 results from the loss of insulin production in the beta cells of the pancreas, and type 2 from a lack of serum insulin or poor uptake of glucose into the cells. Diabetes causes disease in many organs in the body, which may be life-threatening if untreated. Complications such as heart disease, vascular disease, renal failure and blindness (Roberts, 2005) have all been reported. The increased prevalence may be caused by factors such as environmental aspects, diet, an ageing population and low levels of physical exercise.