The Association of HbA1c Variability with 12 Week and 12 Month Outcomes on Diabetes Related Foot Ulcer Healing

Abstract

Introduction This study aimed to determine the relationship between HbA 1c variability and foot ulcer healing at 12 weeks and 12 months. Methods Using National Diabetic Foot Care Audit (NDFA) and hospital records, demographics, baseline ulcer characteristics and healing outcomes for subjects presenting with a foot ulcer between 2017–2022 were collected at 12 weeks and 12 months. Subjects had diabetes duration > 3 years and ≥ 3 HbA 1c recordings in the 5 years prior to presentation. Results At 12 weeks, factors associated with an active ulcer were presence on hind foot (adjusted odds ratios) (2.1 [95% CI 1.3–3.7]), ischaemia (2.1 [95% CI:1.4–3.2]), area > 1 cm 2 (2.7 [95% CI:1.7–4.2]) and diabetes duration > 24 years vs 3–10 (AOR 2.0 [95% CI 1.2–3.5]). After adjustment, HbA 1c variability 6–10 mmol/mol and > 14.5 mmol/mol had AOR of 1.76 (95% CI 1.1–2.8; p = 0.0192) and 1.5 (95% CI 0.9–2.6; p = 0.1148) of an active ulcer at 12 weeks vs variability < 6 mmol/mol. At 12 months, ischaemia (AOR 2.4 [95% CI 1.5–3.8]) and diabetes duration > 24 years vs 3–10 years (AOR 3.3 [95% CI 1.7–6.4] were significant factors. HbA 1c variability was not significant at 12 months. Conclusion In keeping with the national NDFA data, in our cohort ulcer characteristics, but not HbA 1c variability, were the key factors associated with ulcer healing at 12 weeks and 12 months.