The Association of HbA_1c Variability with 12 Week and 12 Month Outcomes on Diabetes Related Foot Ulcer Healing

This study aimed to determine the relationship between HbA_1c variability and foot ulcer healing at 12 weeks and 12 months.

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.

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 cm² (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.

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.