Diabetic foot ulcers can be slow to heal and prone to recurring. A new study employed an existing method, used on burns patients, to assess the degree of water loss from the skin and found that it was a good diagnostic tool for predicting a foot ulcer’s comeback chances.
Foot ulcers are a common complication of diabetes, contributing significantly to morbidity and mortality. They’re a leading cause of non-traumatic amputations because they can be challenging to treat; they are slow to heal and prone to reopening.
In a new study, researchers have applied an existing method for assessing skin integrity, one that is used in patients with burns, to determine the likelihood that a healed diabetic foot ulcer will recur.
“The study is an important initial step to give clinicians treating diabetic foot ulcers a reliable diagnostic aid for the first time to assess an individual’s risk of ulcer recurrence,” said study co-author Teresa Jones, MD, Program Director for the Division of Diabetes, Endocrinology, and Metabolic Diseases and the National Institutes of Health’s (NIH) National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK). “Foot ulcers are such a confounding issue with diabetes and being able to determine which wounds are at highest risk for recurrence could save many lives and limbs.”
Burns damage the skin’s integrity, disrupting its ability to retain water and leading to a high rate of transepidermal water loss (TEWL). High water loss in burn patients can lead to dehydration, electrolyte imbalances, and negatively impact healing. Because TEWL is a widely accepted, objective measure of skin barrier function, the researchers hypothesized that a high TEWL, indicating poor skin barrier function, would be associated with an increased risk of diabetic foot ulcer recurrence. They set out to ascertain whether TEWL could be used as a predictive biomarker in diabetics with a recently healed ulcer.
Over 400 adults with a diabetic foot ulcer that appeared closed or healed to the eye were recruited to the study. Using a commercial device – a handheld, non-invasive probe – five TEWL measurements were taken: four from around the closed wound site, following a clock-face pattern (at three, six, nine, and 12 o’clock), and one from the center. A reference TEWL measurement was taken at an anatomically matched site of intact skin on the other foot.
“Wound closure” was defined according to the US Food and Drug Administration’s (FDA) guidance on treating chronic ulcers and burn wounds. Namely, the “re-epithelialization” or resurfacing of a wound with new skin, without the need for drainage or dressings at two consecutive visits, two weeks apart. Participants were observed for up to 16 weeks to see if the ulcer came back, and had weekly phone contact with the researchers. “Wound recurrence” was defined as a participant answering "Yes" to both questions, “Do you see any discharge from the closed wound?” and “Has the wound reopened?”
Wound recurrence before or up to week 16 occurred in 21.5% of study participants. Of those, 35% had high TEWL, compared with 17% with low TEWL. Participants with high TEWL were 2.7 times more likely to report a wound recurrence than those with low TEWL.
“This work bridges the gap between clinical outcomes (e.g., wound closure) and patient-centered outcomes (e.g., remission days),” said the researchers. “It highlights the critical need to revisit current wound healing clinical end points to include restoration of barrier function at the site of closure.”
The study was published in the journal Diabetes Care.
Source: NIH