What is type 2 diabetes?

Type 2 diabetes is the most common clinical form of diabetes, accounting for about 90% of all cases. It is currently undergoing a worldwide epidemic; the prevalence has tripled during the last 30 years. The most recent surveys in Europe indicate a prevalence of 6% in the middle-aged and older population. In the USA, the prevalence is about 8%. The disease typically affects adults over the age of 40 years and is strongly associated with obesity (> 80% of patients with type 2 diabetes are obese), inactivity, family history of diabetes and ethnic background. In all Western countries, the prevalence of type 2 diabetes is greater in ethnic minority populations than in white populations, though it continues to increase in all groups. In the last 10 years, there has been a shift towards a younger age of onset and an emerging epidemic of the disease in children, adolescents and young adults, most notably in the USA and Japan. Diabetes-related complications are a major cause of disability and suffering and incur costs of 5–10% of gross national health budgets. Diabetes remains the principal cause of renal failure, limb amputations and new-onset blindness and is also a major risk factor for heart disease and stroke.