|This article By Dr Liew Ngoh Chin (for AsiaOneHealth)
DIABETES mellitus is a major global health problem and has reached epidemic proportions in many developed and developing countries. This is contributed by the global changes of population growth, longevity, urbanisation, mechanisation, obesity, and lifestyle. At present, the highest number of people with diabetes is in Europe and America. It is predicted that by 2025, the number of diabetes sufferers in Asia would exceed 100 million.
In Malaysia, the prevalence of diabetes has increased; 4% in the 1980s, 8.3% in 1996, to 14.9% in 2006 – an increase of 250% over 20 years!
It is predicted that if this trend continues, one in every five adult Malaysians above the age of 30 would be diabetic.
Diabetic foot problem
Diabetics are often afflicted with many complications – eye problems, kidney failure, heart attack, stroke, and leg amputations.
Of the complications listed, peripheral arterial disease (PAD) leading to amputation is not commonly recognised. In the National Health and Morbidity Survey 2006 conducted by the Health Ministry, 4% to 7% of known diabetics had undergone toe or leg amputations.
Diabetic foot is defined as a condition of the foot directly caused by diabetes or is due to its long term complications. There are three factors leading to this condition:
1. Peripheral arterial disease – narrowing or blockage of the arterial supply to the foot, causing ischaemia of the tissue.
2. Peripheral neuropathy – an affliction of the nerve of the foot leading to loss of sensation, numbness, paraesthesia or altered sensation, pain, and deformity of the foot and toes.
3. Infection – this occurs as a direct result of the two previous conditions. Diabetics also suffer from impaired immunity, leading to the inability to ward off minor infections.
There has been a misconception that PAD is not common among Asians. On analysis of the publications, the prevalence of PAD in diabetics in Asia ranges from 6% to 23%; a figure equal to, if not higher, than the Caucasian population.
In 2007, a multi-country study was conducted among diabetics in seven Asian countries. The study, known as PAD-SEARCH, involved 6,625 patients and showed a prevalence rate of 17.7% of PAD among diabetic patients.
The risk factors leading to PAD are: duration of diabetes, duration of hypertension, poorly controlled diabetes (high HbA1c), smoking, and high cholesterol.
Diabetic peripheral neuropathy (DPN) is a common affliction of the nerves of the lower extremity. Thirty to 50% of diabetics with disease of longer than 10 years duration suffer from this condition.
DPN may affect the sensory nerves, leading to pain, numbness and tingling, and many other altered sensation and discomfort only patients could describe.
When the motor nerve fibres are involved, patients have imbalances of the small joints in the foot, leading to deformity and loss of normal weight bearing structure of the sole. Unusual bony protrusions become the focus of repeated trauma and ulceration.
It has been estimated that 60% of non-traumatic lower limb amputations in the US is a result of DPN. Involvement of the autonomic nerves in the foot leads to a dry, shiny and scaly skin that is easily traumatised, becoming a port of entry for infection.