The current burden of diabetic foot disease.

Neuropathy and ischaemia are two great pathologies of the diabetic foot which lead to the characteristic features of foot ulceration (neuropathic and ischaemic) and Charcot neuroarthropathy. These can be complicated by infection and eventually may result in amputation (minor or major) and increased mortality. All of these features contribute to considerable clinical and economic burden. Peripheral nerves in the lower limbs are susceptible to different types of damage in patients with diabetes leading to distinctive syndromes. These include symmetrical sensory neuropathy associated with autonomic neuropathy, which advances gradually, and acutely painful neuropathies and mononeuropathies which have a rather acute presentation but usually recover. Ischaemia in the form of peripheral arterial disease is an important contributor to the burden of the diabetic foot. The incidence of atherosclerotic disease is raised in patients with diabetes and its natural history is accelerated. Diabetes causes severe and diffuse disease below-the knee. The lifetime risk of developing a diabetic foot ulcer is between 19% and 34%. Recurrence is common after initial healing; approximately 40% of patients have a recurrence within 1 year after ulcer healing, almost 60% within 3 years, and 65% within 5 years. Charcot neuroarthropathy is characterised by bone and joint destruction on the background of a neuropathy. Its prevalence in diabetes varies from 0.1% to 8%. Infection develops in 50%-60% of ulcers and is the principal pathology that damages diabetic feet. Approximately 20% of moderate or severe diabetic foot infections result in lower extremity amputations. The incidence of osteomyelitis is about 20% of diabetic foot ulcers. Every 20 s a lower limb is amputated due to complications of diabetes. Of all the lower extremity amputations in persons with diabetes, 85% are preceded by a foot ulcer. The mortality at 5 years for an individual with a diabetic foot ulcer is 2.5 times as high as the risk for an individual with diabetes who does not have a foot ulcer. The economic burden exacted on health care systems is considerable and includes direct and indirect costs, with loss of personal earnings and burden to carers. The diabetic foot is a significant contributor to the global burden of disability and reduces the quality of life. It remains a considerable public health problem.