Do honey-impregnated dressings affect glycaemic control?

Written by: Pam Kirby, Naveed Khan, Neeru Dhillon, Elaine Emmerson, Andy Fisher, Jane Thompson, Jaclyn Burnside, Lindsey Chesterton & Devaka Fernando

In recent years, medical grade honey has been increasingly used in wound care products. A range of therapeutic benefits have been attributed to honey, including increased rates of wound healing, antimicrobial properties and reductions in pain and malodour. Here, the authors present a retrospective study that investigates the impact of glycaemia of honey-impregnated dressings used to treat diabetic foot ulcers at a multidisciplinary diabetic foot clinic. The results suggest that honey dressings do not affect glycaemic control in people with diabetes treated with this modality.

Glycaemic control has been identified as an important factor in wound healing. The Department of Health's (DH's) audit standards for care of wounds has glycaemic control as an important criterion, with the aim of keeping blood glucose <11 mmol/L, or a stable HbA_1c level, during the period of ulceration (DH, 2005). this forms one of the aims of the high-impact interventions in promoting wound healing and preventing infection.

Medical grade honey is used in the treatment of diabetic foot ulcers and is thought by some to cause a deterioration in glycaemic control. In this retrospective study, the authors investigated whether glycaemic targets, as specified by the high-impact interventions care bundle (DH, 2005), were met by people with diabetic foot ulcers treated with honey-impregnated (honey) dressings, attending a multidisciplinary diabetic foot clinic.

Methods

To be eligible for inclusion, people with active diabetic foot ulceration must have bee seen by the multidisciplinary diabetic foot clinic during the study period (18th November 2008 to 3rd March 2009). Furthermore, two HbA_1c readings had to have been taken for each participant during the study period.

The primary objective was to determine whether a mean blood glucose <11 mmol/L was maintained by participants during the study period. The secondary aim was to assess the impact of honey dressings on glycaemic control.

Data collected were: age, sex, first HbA_1c reading, second HbA_1c reading, and the dressings used to treat the current episode of ulceration (distinguishing those participants who were treated with honey dressings, and those treated with all other dressing types). Data were extracted from electronic medical records.

Diabetic foot ulcers were treated according to standardised protocol. This comprised:

• Washing the foot thoroughly before each treatment.
• Sharp debridement of necrotic tissue to promote healthy tissue granulation.
• Application of the appropriate dressing.

A case example of a complex diabetic foot ulcer treated successfully with honey dressings is shown in Box 1.

Results

Records showed that 245 people attended the multidisciplinary diabetic foot clinic from 18th November 2008 to  3rd March 2009. Of these, 62 people met the inclusion criteria.

Of those 62 people, 36 received treatment with honey dressings. Of the honey dressings group, 22 were men, and mean age of the group was 53.2 years (range 26-75 years). The mean first HbA_1c reading in this group was 8.32% (standard deviation [SD] 1.49; 67.4 mmol/mol [SD 16.3]). The second HbA_1c reading was slightly lower at 8.19% (SD 1.37; 66.0 mmol/mol [SD 15.0]). There was no statistically significant difference between the first and second HbA_1c readings. Mean blood glucose, as determined by patient assessment of capillary blood glucose was, 10.6 mmol/L in the honey dressings group.

The remaining 26 people who satisfied the inclusion criteria were treated with other, non-honey dressings. This group was made up of a majority of men (16), and mean age of the group was 54.6 years. The mean first HbA_1c reading in the non-honey dressings group was 8.51% (SD 155; 69.5 mmol/mol [SD 16.9]). The second reading was slightly higher at 8.66% (SD 1.35; 71.1 mmol/mol [SD 14.8]). No statistically significant difference was observed between the first and second HbA_1c readings. Mean blood glucose, as determined by patient assessment of capillary blood glucose, was 10.8 mmol/L in the non-honey dressings group.

Discussion

NICE's "ideal" HbA_1c level for people with diabetes is 6.5% (48.0 mmol/mol; National Collaborating Centre for Chronic Conditions, 2008). The mean HbA_1c levels report here, for both groups, are higher than this recommendation. However, when converted, the values reported are <11mmol/L blood glucose - the target set by the DH's (2005) Saving Lives: Reducing Infection, Delivering Clean and Safe Care report. These figures were confirmed by patient assessment of capillary blood glucose.

Among those with active diabetic foot ulcers treated with honey dressings, no significant difference between the first me HbA_1c reading (8.32% [67.4 mmol/mol]) and the second (8.19% [66.0 mmol/mol]) was found. Glycaemia remained stable during the treatment period, suggesting that the honey dressings did not affect glycaemic control in this population. Similar results with regard to glycaemic control were seen in the non-honey dressings group (first mean HbA_1c 8.51% [69.5 mmol/mol], second 8.66% [71.1 mmol/mol]).

The findings reported here support those of Jeffery (2008) who found no significant difference in glycaemia in participants between pre- and post-honey dressings treatment of diabetic foot ulcers. While Jeffery's (2008) study was controlled, the sample size was small (n=17).

Other studies highlight the therapeutic benefits of using honey in the management of wounds. These include:

• Increased rate of wound healing (van der Weyden, 2005; Gethin and Cowman, 2009).
• Antimicrobial qualities (Chambers, 2006).
• Increased patient satisfaction associated with reductions in pain and malodour (Dunford and Hanano, 2004).

No protocol providing guidance on either the amount of honey to use on a wound, or its method of application, was identified in the literature. Some studies applied honey directly to the ulcers (Chambers, 2006; Abdelatif et al, 2008), while others used honey-impregnated dressings (Dunford and Hanano, 2004; Eddy and Gideonsen, 2005; van der Weyden, 2005; Mphande et al, 2007; Jeffery, 2008; Jull et al, 2008; Gethin and Cowman, 2009). Further research is needed to establish a clinical evidence base for the most effective use of medical grade honey in wound care regimens.

Conclusion

The findings of this retrospective study address concerns about the impact of honey dressings on glycaemic control when used to treat diabetic foot ulceration. Allowing for study design limitations, the results suggest that honey dressings do not impact glycaemic control in people with diabetes. However, more rigorously designed studies with larger sample sizes are needed to confirm these findings.

Pam Kirby is a Lead Nurse, Diabetic Foot Clinic Kings Treatment Centre, Sherwood Forest Hospitals NHS Trust; Naveed Khan was studying for a BMedSci at The University of Sheffield at the time of writing; Neeru Dhillon is a Physician (foundation year), Elaine Emmerson is a Specialist Diabetes Nurse, Andy Fisher, Jane Thompson and Jaclyn Burnside are Diabetes Specialist Podiatrists and Lindsey Chesterton is a Specialist Registrar, all are based at The Diabetic Foot Clinic, Kings Treatment Centre, Sherwood Forest Hospitals NHS Foundation Trust, Sutton in Ashfield; Deveka Fernando is a Consultant in Endocrinology and Diabetes and Honorary Professor, the Diabetic Foot Clinic, Kings Treatment Centre, Sherwood Forest Hospitals NHS Foundation Trust, Sutton in Ashfield and the University of Sheffield and Sheffield Hallam University, Sheffield.