311-OR: High Transepidermal Water Loss (TEWL) Associates with Failure to Maintain Wound Closure in Diabetic Foot Ulcers

Introduction and Objective: It’s been more than 25 years since the FDA approved becaplermin gel for diabetic wound healing. The FDA definition for wound closure is complete re-epithelialization confirmed at two consecutive clinical visits two weeks apart. Our objective was to identify participant characteristics, including TEWL, associated with complete wound closure of diabetic foot ulcers (DFU) and re-opening of a DFU within 2 weeks after initial closure in the NIDDK-sponsored Diabetic Foot Consortium TEWL prospective observational cohort study. TEWL measures skin barrier function and functional wound closure by objectively determining restoration of barrier function at the wound-site.

Methods: Among 466 eligible participants who had physician-assessed wound closure at visit 1, 418 (90%) remained eligible and had confirmed closure 2 weeks later. 29 individuals screen failed because of DFU re-opening. We compared the baseline characteristics of the 418 enrolled and 29 screen fail individuals using Wilcoxon rank sum and Fisher’s exact test p-value for continuous and categorical outcomes, respectively.

Results: There were no differences in demographics including age, sex, race, education, employment status, or social support for transportation and dressing change requirements (p>0.1) between groups. However, the screen failure group had a longer duration of the index DFU prior to initial closure (46.6 vs 27.7 weeks, p=0.003), higher frequency of prior total contact casting (TCC) use for DFU offloading (37% vs. 14%, p=0.003), and a higher initial TEWL measurement at healed ulcer midpoint (31.9 vs. 23.5 g/m^2/h, p=0.006).

Conclusion: Individuals who did not maintain wound closure had higher TEWL values at baseline, longer DFU wound duration, and more prior offloading use. These findings are clinically relevant as a higher TEWL measurement suggests complete wound closure may not have occurred, supporting the use of TEWL to identify a healed DFU at the point of care.