Diabetes Q&A

What Do You Need to Know About Diabetes and Foot Care?

Volume 59 - Issue 7 - July 2019

Author:
Kim A. Carmichael, MD—Series Editor

Citation:
Carmichael KA. What do you need to know about diabetes and foot care? Consultant. 2019;59(7):214, 224.

 

Q. What are the standards for foot care in persons with diabetes?

A. The American Diabetes Association (ADA) provides recommendations and standards for foot management.1 A history should be obtained for smoking, eye or renal disease, Charcot foot, prior ulceration, amputation, angioplasty, or vascular surgery. The practitioner should assess for symptoms of neuropathy such as pain, burning, or numbness, as well as for symptoms of claudication. Persons with a history of sensory loss, prior ulceration, or amputation should have foot examination at every visit. A comprehensive foot evaluation should occur at least annually, including assessment for foot deformities, neurological/sensory evaluation, and pulses in the legs and feet.

All persons with diabetes should obtain general preventive foot self-care education. This should include daily inspection for calluses, blisters, cuts, ingrown toenails, ulcers, and burns.

Q. Why is foot care important for persons with diabetes?

A. Foot ulcers and amputations related to neuropathy and/or vascular disease are very common, and early recognition and management can delay or prevent adverse outcomes. In a recent meta-analysis of 19 clinical studies, the incidence of lower-extremity amputations ranged from 78 to 704 person-years with a relative risk (compared with persons without diabetes) ranging from 7.4 to 41.3, with a relative risk in the United States in 2010 of 10.5 (95% CI, 6.0-15.0).2

The history of foot ulcers in persons with diabetes is approximately 5%, with a lifetime risk of close to 15%.3 Although 60% to 80% of ulcers will heal, 10% to 15% will remain active, and 5% to 24% will lead to amputation within the following 6 to 18 months.3

Approximately 50% of persons with a nontraumatic lower-extremity amputation (NLEA) will develop ulcerations and infections in the contralateral limb within the next 18 months, and 58% will require additional amputation within the next 3 to 5 years.4

Q. What are the risk factors for foot ulcers or amputations?

A. Poor glycemic control and smoking are lifestyle variables that increase the risk of diabetic foot ulcers and amputations.1 Other risk factors include prior limb amputation; peripheral neuropathy with loss of peripheral sensation; foot deformities including preulcerative calluses, corns and prior ulcers; peripheral artery disease (PAD); and visual impairment.1 

Persons with a prior ulcer have a 34 times greater risk of developing another ulcer.5 Chronic kidney disease, particularly in persons on dialysis, has a high association with ulcers and NLEA1—particularly in persons with diabetes, where the rate is 4.2 NLEAs per 100 person-years.6 In fact, the rate of foot complications in persons with diabetes is 250% greater among those on dialysis.5 

Foot ulceration and limb amputation are more prevalent with increasing age and duration of diabetes.3 More recent studies have shown an additional risk factor of sodium-glucose cotransporter-2 inhibitor therapy.7 

Of interest, the hemoglobin A1c level is not associated with wound healing or diabetic foot ulcers.8

Q. What methods of evaluation are valuable in the care of diabetic foot ulcers?

A. The clinical history should include symptoms of claudication, decreased walking speed, leg fatigue, and pain. Physical examination should include inspection of the skin and nails, palpation of the pedal pulses, and assessment of sensation with a 10-g monofilament and a 128-Hz tuning fork. In individuals symptomatic for PAD, ankle-brachial index testing should be performed.1,3 Persons with a loss of protective sensation, structural abnormalities, or PAD should be considered for specialty management.

Q. How should diabetic foot ulcers and peripheral vascular disease be treated?

A. The first line of management involves patient education about risk factors and self-care,1,3,5 including proper footwear and ongoing surveillance. Persons with visual or cognitive impairment or physical movement constraints may need to enlist the help of others in their care.

Persons with foot deformities and/or a history of ulcers, preulcerative calluses, and neuropathy often benefit from customized footwear.1 Foot infections may or may not need antibiotic therapy and could benefit from specialized care.1 Chronic wounds should be treated with off-loading and may require debridement.3

Other modalities of care may include growth factors, bioengineered skin substitutes, extracellular matrix proteins and metalloproteinases,3 hyperbaric oxygen,1 or newer methods such as negative-pressure wound therapy3 or a shock-wave device (ie, dermaPACE).9

Kim A. Carmichael, MD, is a professor of medicine in the John T. Milliken Department of Medicine, Division of Endocrinology, Metabolism, and Lipid Research, at the Washington University School of Medicine in St Louis, Missouri. He discloses that he is on the speakers’ bureau for Janssen.

REFERENCES:

  1. American Diabetes Association. 11. Microvascular complications and foot care: Standards of Medical Care in Diabetes—2019. Diabetes Care. 2019;42(suppl 1):S124-S138.
  2. Narres M, Kvitkina T, Claessen H, et al. Incidence of lower extremity amputations in the diabetic compared with the non-diabetic population: a systematic review. PLoS One. 2017;​12(8):e183081.
  3. Alexiadou K, Doupis J. Management of diabetic foot ulcers. Diabetes Ther. 2012;3(1):4.
  4. Kruse I, Edelman S. Evaluation and treatment of diabetic foot ulcers. Clin Diabetes. 2006;​24(2):91-93.
  5. Lavery LA, Hunt NA, LaFontaine J, Baxter CL, Ndip A, Boulton AJM. Diabetic foot prevention: a neglected opportunity in high-risk patients. Diabetes Care. 2010;33(7):1460-1462.
  6. Harding JL, Pavkov ME, Gregg EW, Burrows NR. Trends of nontraumatic lower extremity amputation in end-stage renal disease and diabetes, United States, 2000–2015 [published online May 29, 2019]. Diabetes Care. doi:10.2337/dc19-0296.
  7. Ueda P, Svanström H, Melbye M, et al. Sodium glucose cotransporter 2 inhibitors risk of serious adverse events: nationwide register based cohort study. BMJ. 2018:363:k4365.
  8. Fesseha BK, Abularrage CJ, Hines KF, et al. Association of hemoglobin A1c and wound healing and diabetic foot ulcers. Diabetes Care. 2018;​41(7):1478-1485.
  9. Sanuwave receives FDA de novo decision to immediately market the Dermapace system for the treatment of diabetic foot ulcers in the U.S. [press release]. Suwanee, GA: Sanuwave Health Inc; January 2, 2018. http://www.sanuwave.com/prviewer/release/id/2871709. Accessed June 19, 2019.