Optimal Wound pH and Related Factors in the Healing Process of Diabetes-Related Foot Ulcer: A Prospective Observational Study.

Background and Aims: Delayed healing in diabetes-related foot ulcer (DFU) remains a clinical challenge, and regulating wound pH may offer a promising solution due to its significant role in healing. This study aimed to investigate the relationship between wound pH and healing, and identify factors influencing wound pH at each healing phase. Methods: This prospective observational study included 187 people with diabetes-related ulcer for up to 8 weeks or until healed. Wound pH was measured at the wound bed, wound edge, and peri-wound. Healing status and phase transition from inflammation to proliferation were assessed using DMIST. Receiver operating characteristic and multivariate regression were used to determine optimal pH cut-off and influencing factors. Results: Healing within 3 days was significantly associated with wound bed pH < 6.7 and wound edge pH < 6.8, while wound edge pH > 7.7 indicated transition to the proliferative phase. In the inflammatory phase, higher wound edge pH was associated with inflammation, absence of systemic infection, and necrotic tissue color. In the proliferative phase, lower pH was associated with higher albumin, absence of maceration, use of hydrofiber dressing at both the wound bed and edge, no stingless bee honey on the wound bed, and use of dialkyl carbamoyl chloride and calcium alginate on the wound edge. Conclusions: This study provides novel evidence on specific wound pH thresholds associated with healing outcomes and phase transition in DFU highlighting the importance of controlling pH-related factors to prevent delayed healing and promote healing.