Diabetes mellitus is a growing healthcare problem worldwide, not just in terms of rapid growth of prevalence, but also the complexities and costs associated with effective treatment and management, both of which are without exception lifetime affairs. Amongst the myriad of complications of diabetes that often befall many patients is diabetic foot.
Diabetic foot is an umbrella term that covers various pathologies such as infections, ulceration, and neuropathic arthropathy (alternatively known as neuropathic osteoarthropathy and Charcot joint or Charcot foot), caused by either diabetic neuropathy or peripheral artery disease (PAD) or both. Diabetes is a significant risk factor for PAD as at least 20% of diabetics have it – this percentage is generally recognised as probably too low since it was derived from diagnosis of symptomatic PAD (up to 40% of patients are actually entirely asymptomatic) [1, 2]. More specifically, the most typical symptom of PAD (intermittent claudication) is 3.5 times more prevalent in male diabetics, while female diabetics have an even higher, 8.6-fold increase in prevalence (in comparison with non-diabetics) .
But why is PAD the bane of diabetics who are at risk for diabetic foot (diabetic foot ulcers affect an estimated 15–25% of diabetics during their lifetime) and how does it worsen the complications of diabetic neuropathy ? The answer lies in diminished flow of oxygen and nutrients to the lower extremities, resulting in both changes to skin texture and colour (blueish or pale hue when the leg is in an elevated position) and poor toenail growth – both are additional symptoms of PAD, but can be caused by a myriad of other non-related conditions) . Additionally, the wound healing rate is greatly reduced . And diabetic patients are at a greatly increased risk of lower-extremity wounds due to loss of sensitivity: this, compounded by the effects of PAD and additional deleterious general effects of diabetes on wound healing, has extremely adverse effects on affected individuals .
It should therefore come as no surprise that at least 50%, although some estimates go as high as 76%, of individuals with critical limb ischaemia (CLI), basically an advanced stage of PAD (mortality rate of 20% within 6 months of diagnosis), also have diabetes and they have worse outcomes than their healthy (non-diabetic) counterparts [8-11]. Prevention of onset of such complications, which can quickly spiral out of control, is therefore one of the cornerstones of diabetic foot management, together with holistic treatment/management of diabetes itself.
What to advise a patient with diabetic foot?
Any good medical treatment, not just for diabetes and its complications like diabetic foot, is essentially based on effective prevention, which usually starts with the patient him/herself who should follow his personal physician’s instructions and recommendation. This is usually easier said than done, at least in some cases as the level of verbal comprehension and health literacy greatly fluctuates between different patients [12, 13]. Nevertheless, doctors have to be persistent when discussing the risk minimisation strategy with their patients, including presenting possible complications of them not following instructions to the letter. They are numerous and range from diabetic ulcers, associated infections, decreased mobility and progress to gangrene, osteomyelitis and amputation.
Statistics connected with these complications are truly worrying. Diabetics are at an increased risk of foot infections (incidence rate of 36.5 per 1000 persons per year) and are at more than 4 times greater risk of developing osteomyelitis . They have greatly increased incidence of leg ulceration in general and those who have already had an ulcer (which has healed) are at an increased risk of developing new ones: at least 34% of patients develop a new ulcer within one year of the first one healing and that percentage rises to 70% after a 5-year period . And there is also a strong link between history of foot ulceration and amputation – about 71% of amputations are preceded by a foot ulcer . On top of that, the incidence of lower-limb amputation (LLA) is 8 times higher in diabetics over the age of 45 years (in comparison with non-diabetics) .
Many or at least a part of those complications could be avoided by following a few simple, but crucial steps for maintaining healthy feet.
Five crucial steps for minimising the risk of diabetic foot complication:
- Daily feet inspection (regardless of the amount of physical activity, i.e. walking) with special attention to web spaces and bony prominences, where skin and underlying tissue is particularly thin and sensitive to damage. Any changes (redness, blister formation, inflammation, ulceration, etc.) should be immediately reported.
- Careful cleaning that precludes excessive soaking of feet and haphazard toenail clipping. Feet (specifically the web spaces) should be meticulously dried using a soft towel, but not to the point of excessive dryness (skin cracking increases the chance of infection), which should be managed with (non-irritating) lotions and oil. Toenails should be clipped transversally to minimise the chance of ingrowth (onychocryptosis).
- Comfortable footwear (shoes and socks), preferably those designed especially for diabetics. Shoes should be non-constraining and with an adequate toe-box, while socks are recommended to be made from natural fibres for easier wicking of perspiration and preferably white in colour (easier identification of any skin/wound discharge).
- Comprehensive treatment of PAD (if present) is of equal importance as management of hyperglycaemia. However, this is often mired in difficulties connected with managing (likely) comorbid conditions (sans diabetes, i.e. coronary artery disease, renal disease) and requires an interdisciplinary and holistic approach .
- Effective management of blood glucose is a prerequisite for mitigating harmful effects of diabetes on the nervous and circulatory system and the wound healing mechanism (complications directly associated with diabetic foot) .
Diabetic foot treatment and management should start with an effective prevention programme compromised of several, easy-to-remember steps, which are conveyed to the patient in the most clear and concise manner and if needed supported by clinical evidence.