Chapter 62 Diabetes mellitus
The number of people worldwide with the chronic condition diabetes mellitus has increased dramatically over the past 10 years and is expected to go on rising. As a diagnostic category, diabetes includes numerous disorders, but the two commonest are known as type 1 and type 2 diabetes. At least 2 million people in the UK have diabetes and there are probably another 750 000 who have not been diagnosed. Approximately 5–10% of those diagnosed have type 1, and 85–95% have type 2 diabetes. Both types of diabetes share the symptom of raised blood glucose levels. Abnormally elevated blood glucose levels have adverse consequences in both the short and long term.
Prevention of diabetes
Tuomilehto et al. (2001) demonstrated that type 2 diabetes can be prevented by changes in lifestyle. Participants were middle-aged, overweight and had impaired glucose tolerance (a diabetes risk factor). All received individualized counselling aimed at reducing fat consumption and increasing physical activity. The risk of developing diabetes in the intervention group was reduced by 58% over the period of the trial in comparison to the usual care control group (Fig. 1). Currently, there is no known intervention to prevent type 1 diabetes, but trials are under way in the USA to test the effectiveness of orally administered insulin for those at risk of type 1.
