By the WoundSource Editors

Diabetes is one of the most common and costly conditions encountered in the U.S. health care system. The condition impacts over 23 million people annually, for a total cost of $245 billion per year.¹ Although surgical infections remain the leading cause of non-healing wounds, diabetic infections follow closely behind,² and they impose a substantial financial burden on the U.S. health care system. Treatment of diabetic ulcers in the United States contributes an additional $9 to $13 billion to the direct annual costs associated with diabetes.³

In addition to being costly, diabetic ulcers impact a large portion of those patients with diabetes. Estimates for the lifetime incidence of diabetic foot ulceration is between 19% and 34% of the diabetic population, meaning that it could affect nearly one in three of these patients. Moreover, recurrence of the ulcer is common. Approximately 40% of patients will have a recurrence within one year of ulcer healing, 60% will experience recurrence within three years, and 65% will have a recurrent ulcer within five years.⁴ The presence of a previous ulcer or amputation is the largest risk factor in the development of foot ulcers. Multiple other risk factors may include the following entities.

Specific Risk Factors for Diabetic Foot Ulcers

Neuropathy
The presence of any form of diabetic neuropathy, and especially polyneuropathy that manifests with numbness or pain, and altered vibration, position, and temperature sensations are strongly associated with the development of diabetic foot ulcers. The disconnection between sensation that patients feel and the actual state of their limbs puts them at increased risk of developing a lesion that may progress to an ulcer. Risk increases further when there is a current or past history of foot ulcer, gangrene, or amputation.⁵

Peripheral Vascular Disease
Peripheral vascular disease leads to insufficient blood flow, particularly in the lower extremities. The resulting ischemia can increase the risk of infection and necrosis. Surgical intervention can be used to help restore adequate blood flow.⁴

Presence of Pre-ulcerative Lesions
Recognizing new lesions in patients with diabetes is crucial in preventing foot ulcers. Calluses, particularly if they are hemorrhagic, and areas that are prone to repetitive shear or stress frequently result in the development of ulcers. Sources of stress can be identified by using a pressure platform and in-shoe pressure sensors so that optimal footwear (that decreases the risk of forming lesions) can be selected.⁴

Hypertension
Hypertension is present in more than half of the patients with diabetes who develop foot ulceration. Oral agents and insulin combination therapy can help to manage this condition.⁵

Sex and Age
The majority of patients with diabetes who develop foot ulcers are male (more than two-thirds). Furthermore, most of them are between 40 and 70 years of age.⁶ Older patients face significantly more complications than younger ones.⁵

Smoking
Smoking is associated with the development of foot ulcers and gangrene, including other comorbidities such as arterial and vascular disease and chronic obstructive pulmonary disease. These conditions have a negative impact on healing and can contribute to the continued presence of lesions that may become ulcers.⁷

Charcot Joint
A Charcot joint develops when bones, joints, and the soft tissue of the foot and ankle are inflamed as a result of neuropathy. The development of this condition can lead to bone destruction, subluxation, dislocation, and deformity and contributes to the risk of developing a diabetic foot ulcer.⁵

Other Risk Factors
The previously discussed risk factors represent the largest identified risks for developing foot ulcers. Other factors may confer a smaller risk while still contributing to the eventual development of an ulcer. These factors include the length of time the patient has had diabetes, impaired visual acuity (which increases the risk of trauma), chronic renal disease, obesity, and sustained uncontrolled hyperglycemia.

Conclusion

Diabetic foot ulcers represent a very complex and difficult to treat wound. More than half of diabetic ulcers become infected, and about 20% lead to some level of amputation. The risk of death within five years for diabetic patients with ulceration is 2.5 times higher than in diabetic patients with no foot ulcer. Understanding the risk factors is often the first step in learning to manage and treat foot ulcers effectively.

References
1. Centers for Disease Control and Prevention (CDC). (National Diabetes Statistics Report, 2017. Atlanta, GA: CDC; 2017.
2. Nussbaum SR, Carter MJ, Fife CE, et al. An economic evaluation of the impact, cost, and Medicare policy implications of nonhealing wounds. Value Health. 2018;21(1):27-32.
3. Raghav A, Khan ZA, Labala RK, et al. Financial burden of diabetic foot ulcers to world: a progressive topic to discuss always. Ther Adv Endocrinol Metab. 2018;9(1):29-31.
4. Armstrong DG, Boulton AJM, Bus SA. Diabetic foot ulcers and their recurrence. N Engl J Med. 2017;376(24):2367-2375.
5. Al-Rubeaan K, Derwish MA, Ouizi S, et al. Diabetic foot complications and their risk factors from a large retrospective cohort study. PloS One. 2015;10(5):e0124446.
6. Ahmad W, Khan IA, Ghaffar S, et al .
7. American Heart Association. Cardiovascular Disease and Diabetes. Dallas, TX: American Heart Association; 2018.

The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.