No Link Between HbA1c Levels and Wound Healing in Patients With Diabetic Foot Ulcers

There does not appear to be an association between baseline and prospective hemoglobin A1c (HbA1c) levels on wound healing in patients diagnosed with diabetic foot ulcers, according to a study published in Diabetes Care.

Researchers performed a retrospective analysis of an ongoing prospective, clinic-based observational study of patients diagnosed with diabetic foot ulcers being treated at the Johns Hopkins Multidisciplinary Diabetic Foot and Wound Clinic in Baltimore, Maryland, over the course of 4.7 years.

The purpose of the study was to evaluate the association between baseline HbA1c levels and wound healing of diabetic foot ulcers and the association between wound healing and changes in HbA1c from baseline HbA1c levels. The primary outcome was to assess time to wound healing.

It was hypothesized that a shorter time to wound healing of diabetic foot ulcers would be associated with tighter glycemic control.

HbA1c changes from baseline were assessed and classified as either nadir (difference between the baseline HbA1c and the lowest prospective HbA1c postbaseline) or mean HbA1c change (difference between the baseline and average of all prospective HbA1c result). A total of 270 individuals with a total of 584 wounds were included in this retrospective analysis.

There were no differences in hazard ratios (HRs) found between the reference group with a baseline HbA1c of 6.5% to 8.0% and those with a baseline of HbA1c of <6.5% and >8.0%. In addition, there were no associations between baseline HbA1c and incident foot ulcer wound healing related to short- or long-term outcomes (<90 days and ≥90 days).

There were no associations between nadir HbA1c change or mean HbA1c change from baseline and wound healing for participants with HbA1c <7.5% or ≥7.5%. There was a paradoxical association with nadir HbA1c change, after adjustment for a greater number of cofounders, the highest tertile of change being associated with wound healing, demonstrating a hazard ratio of 1.90 (95% CI, 1.03-3.53; P =.04).

Researchers concluded that there was no observed association between baseline HbA1c and wound treatment, with no accelerated rates of wound healing observed with changes in HbA1c measures prospectively. There was a paradoxal positive association between increase in HbA1c at baseline (<7.5%) and long-term wound healing; however, this was only related to the nadir and not observed with the mean change in HbA1c. “Further studies are needed to confirm this finding,” concluded the researchers.

Reference

Fesseha BK, Abularrage CJ, Hines KF, et al. Association of hemoglobin A1C and wound healing in diabetic foot ulcers [published online April 16, 2018]. Diabetes Care. doi: 10.2337/dc17-1683