Systemic nutritional interventions for treating foot ulcers in people with diabetes

Nutritional interventions for treating foot ulcers in people with diabetes

BACKGROUND

Foot ulcers in people with diabetes are non-healing, or poorly healing, partial, or full-thickness wounds below the ankle. These ulcers are common, expensive to manage and cause significant morbidity and mortality. The presence of a wound has an impact on nutritional status because of the metabolic cost of repairing tissue damage, in addition to the nutrient losses via wound fluid. Nutritional interventions may improve wound healing of foot ulcers in people with diabetes.

OBJECTIVES

To evaluate the effects of nutritional interventions on the healing of foot ulcers in people with diabetes.

SEARCH METHODS

In March 2020 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated the effect of nutritional interventions on the healing of foot ulcers in people with diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors, working independently, assessed included RCTs for their risk of bias and rated the certainty of evidence using GRADE methodology, using pre-determined inclusion and quality criteria.

MAIN RESULTS

We identified nine RCTs (629 participants). Studies explored oral nutritional interventions as follows: a protein (20 g protein per 200 mL bottle), 1 kcal/mL ready-to-drink, nutritional supplement with added vitamins, minerals and trace elements; arginine, glutamine and β-hydroxy-β-methylbutyrate supplement; 220 mg zinc sulphate supplements; 250 mg magnesium oxide supplements; 1000 mg/day omega-3 fatty acid from flaxseed oil; 150,000 IU of vitamin D, versus 300,000 IU of vitamin D; 250 mg magnesium oxide plus 400 IU vitamin E and 50,000 IU vitamin D supplements. The comparator in eight studies was placebo, and in one study a different dose of vitamin D. Eight studies reported the primary outcome measure of ulcer healing; only two studies reported a measure of complete healing. Six further studies reported measures of change in ulcer dimension, these studies reported only individual parameters of ulcer dimensions (i.e. length, width and depth) and not change in ulcer volume. All of the evidence identified was very low certainty. We downgraded it for risks of bias, indirectness and imprecision. It is uncertain whether oral nutritional supplement with 20 g protein per 200 mL bottle, 1 kcal/mL, nutritional supplement with added vitamins, minerals and trace elements, increases the proportion of ulcers healed at six months more than placebo (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.42 to 1.53). It is also uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement increases the proportion of ulcers healed at 16 weeks compared with placebo (RR 1.09, 95% CI 0.85 to 1.40). It is uncertain whether the following interventions change parameters of ulcer dimensions over time when compared with placebo; 220 mg zinc sulphate supplement containing 50 mg elemental zinc, 250 mg magnesium oxide supplement, 1000 mg/day omega-3 fatty acid from flaxseed oil supplement, magnesium and vitamin E co-supplementation and vitamin D supplementation. It is also uncertain whether 150,000 IU of vitamin D, impacts ulcer dimensions when compared with 300,000 IU of vitamin D. Two studies explored some of the secondary outcomes of interest for this review. It is uncertain whether oral nutritional supplement with 20 g protein per 200 mL bottle, 1 kcal/mL, nutritional supplement with added vitamins, minerals and trace elements, reduces the number of deaths (RR 0.96, 95% CI 0.06 to 14.60) or amputations (RR 4.82, 95% CI 0.24 to 95.88) more than placebo. It is uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement increases health-related quality of life at 16 weeks more than placebo (MD -0.03, 95% CI -0.09 to 0.03). It is also uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement reduces the numbers of new ulcers (RR 1.04, 95% CI 0.71 to 1.51), or amputations (RR 0.66, 95% CI 0.16 to 2.69) more than placebo. None of the included studies reported the secondary outcomes cost of intervention, acceptability of the intervention (or satisfaction) with respect to patient comfort, length of patient hospital stay, surgical interventions, or osteomyelitis incidence. One study exploring the impact of arginine, glutamine and β-hydroxy-β-methylbutyrate supplement versus placebo did not report on any relevant outcomes.

AUTHORS' CONCLUSIONS

Evidence for the impact of nutritional interventions on the healing of foot ulcers in people with diabetes compared with no nutritional supplementation, or compared with a different dose of nutritional supplementation, remains uncertain, with eight studies showing no clear benefit or harm. It is also uncertain whether there is a difference in rates of adverse events, amputation rate, development of new foot ulcers, or quality of life, between nutritional interventions and placebo. More research is needed to clarify the impact of nutritional interventions on the healing of foot ulcers in people with diabetes.

Broad-Ranging Nutritional Deficiencies Predict Amputation in Diabetic Foot Ulcers

Diabetic foot ulcers present across the spectrum of nonhealing wounds, be it acute or many months duration. There is developing literature highlighting that despite this group having high caloric intake, they often lack the micronutrients essential for wound healing. This study reports a retrospective cohort of patients’ micro- and macro-nutritional state and its relationship to amputation. A retrospective cohort was observed over a 2-month period at one of Australia’s largest tertiary referral centers for diabetic foot infection and vascular surgery. Patient information, duration of ulcer, various biochemical markers of nutrition and infection, and whether the patient required amputation were collected from scanned medical records. A cohort of 48 patients with a broad-spectrum of biochemical markers was established. Average hemoglobin A1c (HbA1c) was 8.6%. A total of 58.7% had vitamin C deficiency, including 30.4% with severe deficiency, average 22.6 Ł} 5.8 μmol/L; 61.5% had hypoalbuminemia, average albumin 28.7 Ł} 2.5 g/L. Average vitamin B12 was 294.6 Ł} 69.6 pmol/L; 57.9% had low vitamin D, average 46.3 Ł} 8.3 nmol/L. Basic screening scores for caloric intake failed to suggest this biochemical depletion. There was a 52.1% amputation rate; biochemical depletion was associated with risk of amputation with vitamin C ( P < .01), albumin ( P = .03), and hemoglobin ( P = .01), markedly lower in patients managed with amputation than those managed conservatively. There was no relation between duration of ulceration and nutrient depletion. Patients with diabetic foot ulceration rely on multidisciplinary care to optimize their wound healing. An important but often overlooked aspect of this is nutritional state, with micronutrients being very important for the healing of complex wounds. General nutritional screening often fails to identify patients at risk of micronutrient deficiency. There is a high prevalence of vitamin deficiency in patients with diabetic foot ulcers. This presents an excellent avenue for future research to assess if aggressive nutrient replacement can improve outcomes in this cohort of patients.

Malnutrition in type 2 diabetic patients does not affect healing of foot ulcers

AIM

Protein-energy malnutrition is known to be involved in wound healing. While wound healing in patients with diabetic foot ulcers (DFU) is a complex and multifactorial process, the role of malnutrition in this case has rarely been explored. The objective of this study was to determine whether the nutritional status of diabetic patients influences the healing of DFU.

METHODS

48 patients were included in this prospective, single-center study. All patients with comorbidities or factors involving malnutrition or influencing biological measurements were excluded. Patients were followed up for 24 weeks.

RESULTS

The malnutrition rate was 29.2% at baseline and 25.6% at the end of the study. The difference was not significant. Of the 35 patients with wound healing, 29% were undernourished at inclusion and 17% at the end of the study. Of the 12 patients without wound healing, 50% were undernourished at inclusion, and 42% at the end of the study. These differences were not significant. Rate and speed of wound healing were not associated with malnutrition at inclusion. 15% of patients without malnutrition at baseline had final malnutrition.

CONCLUSION

We demonstrated that wound healing was not affected by the initial presence of malnutrition. In our study, there is no evidence to support nutritional intervention to improve wound healing in diabetic patients. Nevertheless, malnutrition is responsible for an increase in morbidity and mortality and it is essential to identify malnutrition systematically for all patients with DFU, initially and during follow-up to treat it quickly and efficiently.