The impact of glycaemic variability on wound healing in the diabetic foot - A retrospective study of new ulcers presenting to a specialist multidisciplinary foot clinic

Risk factors associated with the recurrence of diabetic foot ulcers: A meta-analysis

AIMS

Diabetic foot ulcers have caused significant medical, economic and social consequences for patients, families and society. With appropriate treatment, many diabetic foot ulcers can heal, temporarily avoiding possible amputation. Unfortunately, even if foot ulcers subside, recurrence is still common. The recurrence of ulcer has brought another physical and psychological trauma to diabetic foot patients who yearn for a better life. Therefore, it may be more useful to evaluate the factors associated with ulcer recurrence in diabetic foot ulcer patients.

METHODS

The PubMed, Web of Science, Embase and China National Knowledge Infrastructure databases were comprehensively searched for prospective or retrospective studies published up to February 1, 2024. All English or Chinese language studies on diabetic foot ulcer patients who experience recurrence were included, and RevMan 5.3 software was used to analyze the data.

RESULTS

A total of 22 studies meeting the eligibility criteria were ultimately included in this meta-analysis. 1861 of 5252 diabetic foot ulcer patients experienced recurrence during follow-up. The following variables were associated with an increased risk of ulcer recurrence: male (OR = 1.26, 95% CI = 1.10 ~ 1.44, P = 0.0009), smoking history (OR = 1.18, 95% CI = 1.04 ~ 1.35, P = 0.01), living alone (OR = 1.86, 95% CI = 1.21 ~ 2.86, P = 0.004), plantar ulcers (OR = 2.44, 95% CI = 1.41 ~ 4.23, P = 0.001), diabetic retinopathy (OR = 1.59, 95% CI = 1.35 ~ 1.88, P < 0.00001), diabetic nephropathy (OR = 1.37, 95% CI = 1.12 ~ 1.68, P = 0.002), diabetic peripheral neuropathy (OR = 1.78, 95% CI = 1.45 ~ 2.19, P < 0.00001), foot deformity (OR = 2.51, 95% CI = 1.85 ~ 3.40 P < 0.00001) and peripheral arterial disease (OR = 3.10, 95% CI = 2.43 ~ 3.95 P < 0.00001). However, hypertension (OR = 1.16, 95% CI = 0.96 ~ 1.40, P = 0.13) and body mass index (MD = 0.20, 95% CI = -0.12 ~ 0.53, P = 0.22) were not associated with diabetic foot ulcer recurrence.

CONCLUSIONS

Our meta-analysis identified the following important risk factors for diabetic foot ulcer recurrence: male sex, smoking history, living alone, plantar ulcer, diabetic retinopathy, diabetic nephropathy, diabetic peripheral neuropathy, foot deformity, and peripheral arterial disease. Understanding these factors and their impact on ulcer recurrence is crucial for multidisciplinary teams to develop management and treatment plans for diabetic foot ulcer patients.

Exercise Training for People With Diabetes-related Foot Ulcers---A Systematic Review of Glycemia, Fitness, and Wound-healing Outcomes

OBJECTIVES

Regular physical activity is a key, patient-centred therapy for people with diabetes to manage their glycemia. The International Working Group on the Diabetic Foot recommends optimization of glycemic control for people with/at risk of diabetes-related foot ulcer (DFU); however, people with DFU are commonly instructed by clinicians to avoid physical activity so as not to worsen the ulcer. The effects of exercise on glycemia, fitness, and wound healing in people with active DFU are not clear. In this study we examined the effects of regular exercise (training) on glycemia, cardiorespiratory fitness, muscular strength, metabolic health, and ulcer healing in adults with diabetes and an active foot ulcer.

METHODS

Online databases and reference lists of included studies were searched from earliest records to December 2023. Studies involving adult populations with DFU and incorporating interventions of exercise training were included. Data were extracted independently by 2 reviewers.

RESULTS

Of the 5,592 studies screened, 8 were included, with a total of 213 participants. Exercise interventions involved foot range-of-movement exercises and/or aerobic and/or resistance-type exercise. None of the studies reported on cardiorespiratory fitness or anthropometry and limited data were available for glycemic and muscular strength outcomes. Interpretation of data on safety, wound healing, and adherence to exercise were limited due to inconsistent reporting.

CONCLUSIONS

Despite some data that exercise may have a positive impact on wound healing, evidence regarding its benefits and safety is significantly lacking, despite metabolic (particularly glycemic) and fitness outcomes being core to the rationale for exercise therapy in diabetes. Given the importance of exercise in current management guidelines for diabetes, and the plausibility of positive health effects of exercise training for people with DFU, there is a need for research to move from foot-focussed to person-centred outcomes to better inform the implementation of exercise therapy for people with DFU.

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

INTRODUCTION

This study aimed to determine the relationship between HbA1c 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 HbA1c 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 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, HbA1c 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. HbA1c variability was not significant at 12 months.

CONCLUSION

In keeping with the national NDFA data, in our cohort ulcer characteristics, but not HbA1c variability, were the key factors associated with ulcer healing at 12 weeks and 12 months.

Glycemic Variability as a Predictor of Graft Failure Following Infrainguinal Bypass for Peripheral Arterial Disease: A Retrospective Cohort Study

BACKGROUND

Glycemic variability (GV), measured as the change in visit-to-visit glycated hemoglobin (HbA1c), increases the risk of multiple adverse outcomes. However, the impact of GV on graft patency following infrainguinal bypass (IIB) is unknown. A retrospective cohort study was undertaken to assess the impact of GV on graft patency.

METHODS

A 3-year single-center retrospective case notes analysis of all people undergoing IIB between 2017 and 2019. Rutherford stage, graft conduit, level of bypass, procedure details, baseline demographics, comorbidities, and GV were assessed. Time to reintervention, ipsilateral amputation, or death was recorded to determine primary patency (PP).

RESULTS

One hundred six IIB outcomes were analyzed: mean (± standard deviation) age 68.0 (9.2) years; 69 (65.1%) male, 37 (33.9%), 75 (70.8%) had diabetes mellitus; and 46 (43.4%) underwent elective procedures. GV > 9.1% was associated with significantly lower median PP than GV < 9.1%, 198 (97-753.5) vs. 713 (166.5-1,044.5) days (P = 0.045). On univariate analysis, GV > 9.1% vs. < 9.1% was significantly associated with PP (hazard ratio [HR] 1.85 [confidence interval {CI} 1.091-3.136], P = 0.022). Bypass level was also a univariate predictor, with below knee bypasses (HR 2.31 [CI 1.164-4.564], P = 0.017), and tibial (HR 2.00 [CI 1.022-3.090], P < 0.043) having lower PP than above knee bypasses. On multivariate adjustment, GV > 9.1% and level of bypass remained independent predictors of PP, HR 1.96 (95% CI: 1.12-3.42, P = 0.018) and HR 2.54 (95% CI: 1.24-5.22, P = 0.011), respectively.

CONCLUSIONS

GV is an independent predictor of PP following infrainguinal bypass, thus optimizing GV should be a therapeutic target.

Short-term glucose variability as a determinant of the healing rate of diabetic foot ulcer: A retrospective study

BACKGROUND

The aim of this study was to describe the clinical characteristics of people with diabetic foot ulcer (DFU) according to glucose variability (GV) and to investigate the relationship between GV and DFU outcome in a population with type 2 diabetes (T2D) and DFU.

METHODS

This is a retrospective study of 300 individuals aged 64.3 years (181 males) treated for DFU in a tertiary-care center with a regular follow-up for 6 months. Laboratory measurements and clinical assessments were collected at baseline. According to the coefficient of variation (CV) cut-off (≥36%), people were divided into two groups (low and high GV).

RESULTS

Compared with low GV group (n = 245), high GV group (n = 55) had significant longer duration of diabetes [low vs high GV, mean ± Standard Deviation (SD), 17.8 ± 11.8 vs 22.4 ± 10.8, P = 0.012], higher levels of glycated haemoglobin [median (IQR), 7.4 (6.6, 8.8) vs 8.2 (7.0, 9.6), P = 0.010] and urinary albumin excretion [25.2 (11.9, 77.0) vs 48.0 (23.2, 106.0), P = 0.031]. Moreover, 10 days self-monitoring of blood glucose-derived glycemic metrics were significantly different between groups. No differences among clinical features were found. The multiple logistic regression analysis identified CV and SD as negative predictors of healing.

CONCLUSIONS

In a population of people with T2D and DFU treated in a tertiary-care center, individuals with high GV had a 3-fold higher risk of healing failure, as compared with those with low GV. CV and SD were related to poor healing within 6 months follow-up.

Visit to Visit Hemoglobin A1c Variation and Long-term Risk of Major Adverse Limb Events in Patients With Type 2 Diabetes

CONTEXT

Glycemic variation had been demonstrated to be associated with several complications of diabetes.

OBJECTIVE

Investigation of the association between visit to visit hemoglobin A1c (HbA1c) variation and the long-term risk of major adverse limb events (MALEs).

METHODS

Retrospective database study. Average real variability was used to represent glycemic variations with all the HbA1c measurements during the 4 following years after the initial diagnosis of type 2 diabetes. Participants were followed from the beginning of the fifth year until death or the end of the follow-up. The association between HbA1c variations and MALEs was evaluated after adjusting for mean HbA1c and baseline characteristics. Included were 56 872 patients at the referral center with a first diagnosis of type 2 diabetes, no lower extremity arterial disease, and at least 1 HbA1c measurement in each of the 4 following years were identified from a multicenter database. The main outcome measure was incidence of a MALE, which was defined as the composite of revascularization, foot ulcers, and lower limb amputations.

RESULTS

The average number of HbA1c measurements was 12.6. The mean follow-up time was 6.1 years. The cumulative incidence of MALEs was 9.25 per 1000 person-years. Visit to visit HbA1c variations were significantly associated with MALEs and lower limb amputation after multivariate adjustment. People in the highest quartile of variations had increased risks for MALEs (HR 1.25, 95% CI 1.10-1.41) and lower limb amputation (HR 3.05, 95% CI 1.97-4.74).

CONCLUSION

HbA1c variation was independently associated with a long-term risk of MALEs and lower limb amputations in patients with type 2 diabetes.

Does Metabolic Control Have Any Influence on the Clinical Presentation and Short-Term Outcomes of Diabetic Foot Infections?

Objective: We hypothesized that patients with poor glycemic control undergoing treatment for diabetic foot infections (DFIs) would have a poorer prognosis than those with better metabolic control assessed by glycated hemoglobin (HbA1c). Approach: We analyzed a retrospective cohort of 245 patients with moderate and severe DFIs. HbA1c values were dichotomized (<7% or ≥7% and ≤75th percentile (P75) and >P75) to analyze patient outcomes regarding metabolic control. The present study adhered to the STROBE guidelines for cohort studies. Results: One hundred sixty-nine patients (69%) were men. Their mean age was 60.7 years (10.8). HbA1c ≥7% was detected in 203 patients (82.9%). P75 HbA1c was 10.9%. After performing univariate analysis, we found an association of HbA1c <7% with major amputations and mortality. However, after applying the logistic regression model, we did not find HbA1c <7% to be a predictive factor of major amputation. The risk factors for mortality following application of Cox's proportional hazards model were osteomyelitis (HR: 0.2, 95% CI: 0.07-0.62, p < 0.01), eGFR <60 mL/min/1.73 m² (HR: 2.7, 95% CI: 1.0-7.5, p = 0.04), and HbA1c <7% (HR: 4.9, 95% CI: 1.8-13.2, p < 0.01). Innovation: The group with optimal glycemic control (HbA1c <7%) had a shorter survival time than those with worse metabolic control. Conclusions: We did not find a longer duration of hospitalization, a higher rate of amputations, or longer healing times in the groups with worse metabolic control. HbA1c <7% was a risk factor for mid-term mortality.

Usefulness of continuous glucose monitoring of blood glucose control in patients with diabetes undergoing hemodialysis: A pilot study

Background

Blood glucose stability has recently been considered important in the treatment of diabetes. Both hypoglycemia and hyperglycemia can frequently occur in patients with diabetes undergoing hemodialysis. This study aimed to determine the usefulness of continuous glucose monitoring (CGM) for glycemic control and glycemic variability stabilization in patients with diabetes undergoing hemodialysis.

Materials and methods

Eighteen patients aged ≥18 years with type 1 or 2 diabetes and ≥3 months on hemodialysis at the Eulji Medical Center, Daejeon, Republic of Korea between November 2021 and May 2022 were included. Patients underwent 7 days CGM twice: the baseline study period (T0) and the follow-up study period (T1), at a 12 weeks interval. Physicians modified the treatment strategy according to the T0 results, and then patients conducted T1. As indicators of glycemic control, the mean glucose levels, glycated hemoglobin A1c (HbA1c), and time in range were measured. As indicators of glycemic variability, standard deviation (SD) and % coefficient variation (%CV) were measured.

Results

Data from 18 patients were analyzed. The mean glucose levels, HbA1c, SD, and %CV improved in T1 compared to T0 (P < 0.05). During T0, the mean glucose level was significantly lower on a day with hemodialysis than on a day without (P < 0.05), and SD and %CV were significantly higher on a day with hemodialysis than on a day without (P < 0.05). After the physicians modified the treatment according to the T0 results, there were no differences in the mean glucose levels, SD, and %CV between days with and without hemodialysis during T1.

Conclusion

Continuous glucose monitoring could be a promising tool for individualizing treatment strategies in patients with diabetes undergoing hemodialysis.

Early Worsening of Retinopathy in Type 1 and Type 2 Diabetes After Rapid Improvement in Glycaemic Control: A Systematic Review

To systematically review the epidemiology of early worsening of diabetic retinopathy (EWDR) after substantial improvements in glycaemic control and evaluate characteristics including risk factors. This systematic review was registered with PROSPERO (CRD42020158252). An electronic literature search was performed according to PRISMA guidelines using MEDLINE, EMBASE, PubMed, Web of Science, Scopus and Cochrane databases and manual reference for the articles published until 2020. Published full-text English language articles that report data on diabetic retinopathy in people with diabetes experiencing a rapid, substantial decrease in HbA1c after going through intensive therapy were included. All articles were screened, data were extracted and methodological quality was evaluated by two independent reviewers using a priori criteria. A total of 346 articles were identified after the removal of duplicates. Data were extracted from 19 full-text articles with a total of 15,588 participants. Included studies varied considerably in terms of patient selection, timing and method of assessing the eye and retinopathy classification. EWDR was reported to occur in a wide range of prevalences; 3.3-47% of participants within 3-84 months after intensification of glycaemic control. Risk factors for EWDR included long duration of diabetes, long-term uncontrolled hyperglycemia, amplitude of and baseline retinopathy severity in both type 1 and type 2 diabetes. The occurrence of EWDR and progression of retinopathy were found to have an association with the amplitude of HbA1c reduction. EWDR has been described in a proportion of people with intensification of glycaemic control. However, the prevalence remains unclear because of methodological differences in the identified studies. Future interventional studies should report retinopathy and visual outcomes using standardized protocols.

Factors influencing lower extremity amputation outcomes in people with active foot ulceration in regional Australia: A retrospective cohort study

Australia has the second highest rate of non-traumatic lower extremity amputation (LEA) globally. Australia's large geographical size is one of the biggest challenges facing limb preservation services and may be contributing to LEA. The aim of this study was to determine what factors contribute to the likelihood of LEA in people with active foot ulceration in regional Australia. This retrospective cohort study audited patients with active foot ulceration in a multidisciplinary high risk foot service (HRFS) in regional Australia. Neurological, vascular and wound characteristics were systematically extracted, along with demographic information. Participants were followed for at least 12 months until healing or LEA occurred. Correlations between LEA and clinical and demographic characteristics were assessed using the Pearson's product moment correlation coefficient and chi squared test for independence. Significant variables (p < 0.05) were included in the model. Direct logistic regression assessed the independent contribution of significantly correlated variables on the likelihood of LEA. Of note, 1876 records were hand screened with 476 participants (25%) meeting the inclusion criteria. Geographical distance from the HRFS, toe systolic pressure (TSP), diabetes and infection were all significantly correlated with LEA and included in the logistic regression model. TSP decrease of 1 mmHg (OR 1.02, 95% CI 1.01-1.03), increased geographical distance (1 km) from HRFS (OR 1.006, 95% CI 1.001-1.01) infection (OR 2.08, 95% CI 1.06-4.07) and presence of diabetes (OR 3.77, 95% CI 1.12-12.65) were all significantly associated with increased likelihood of LEA. HRFS should account for the disparity in outcomes between patients living in close proximity to their service, compared to those in rural areas. Optimal management of diabetes, vascular perfusion and control of infection may also contribute to preventing LEA in people with active foot ulceration.

The Association Between Mean Glycated Haemoglobin or Glycaemic Variability and the Development of Retinopathy in People with Diabetes: A Retrospective Observational Cohort Study

INTRODUCTION

To determine the association between mean glycated haemoglobin (HbA_1c) or glycaemic variability and the development of diabetic retinopathy (DR) in people with diabetes.

METHODS

An observational cohort study with people registered with a DR eye screening service between October 2012 and October 2017. Those who had no DR at the start of the study were followed for a maximum of 5 years. HbA_1c measures were used to calculate HbA_1c variability and mean HbA_1c to assess any relationship between these and the risk of developing new onset DR.

RESULTS

A total of 2511 individuals were followed up for up to 5 years. Of these, 542 (21.6%) developed DR. After adjustment, HbA_1c variability was not significantly associated with the development of DR (p = 0.3435). However, the mean HbA_1c was (p < 0.0001). Those with type 1 diabetes had an odds of 1.63 (95% CI 1.11-2.40) of a retinopathy diagnosis compared to those with type 2 diabetes.

CONCLUSIONS

We have shown that mean HbA_1c is associated with an increased risk of developing diabetic retinopathy. However, after adjustment for sex, age, diabetes type and the mean, the HbA_1c variability no longer remained significant. Our data suggest that optimizing long-term glycaemic control remains paramount.

Current concepts and clinical importance of glycemic variability

BACKGROUND AND AIMS

Evolving evidence indicate that variations in blood glucose levels are likely to be an important factor in developing diabetic complications. Monitoring glucose fluctuations in patients remains as a therapeutic challenge and more evidence needs to be created in order to bring GV into limelight. This review encapsulates the most important findings conducted and discusses on them to provide readers a better understanding on this emerging subject.

METHODS

Keyword-based comprehensive desktop search was conducted to gather the relevant literature. Triple-stage cascade type content analysis of the literature was conducted to draw relevant themes of discussions.

RESULTS

High glycemic variability is associated with an increased risk of development of diabetic complications especially in cardiac conditions. The widely used and accepted metrics to determine the variations in blood glucose are Standard deviation (SD), MAGE (Mean amplitude of glycemic excursions) and MODD (Mean of daily differences). Occurrence of blood glucose variations affects at a molecular level thereby causing more harm than the occurrence of hyperglycemia alone.

CONCLUSION

Available data suggest that Glycemic Variability should be used as an additional marker of glycemia. Additional research globally, and in India are required.

3D scaffolds in the treatment of diabetic foot ulcers: New trends vs conventional approaches

Diabetic foot ulcer (DFU) is a serious complication of diabetes mellitus, affecting roughly 25% of diabetic patients and resulting in lower limb amputation in over 70% of known cases. In addition to the devastating physiological consequences of DFU and its impact on patient quality of life, DFU has significant clinical and economic implications. Various traditional therapies are implemented to effectively treat DFU. However, emerging technologies such as bioprinting and electrospinning, present an exciting opportunity to improve current treatment strategies through the development of 3D scaffolds, by overcoming the limitations of current wound healing strategies. This review provides a summary on (i) current prevention and treatment strategies available for DFU; (ii) methods of fabrication of 3D scaffolds relevant for this condition; (iii) suitable materials and commonly used molecules for the treatment of DFU; and (iv) future directions offered by emerging technologies.

Vitamin D Status in a Bulgarian Population With Type 2 Diabetes and Diabetic Foot Ulcers

The aim of this study was to assess vitamin D status in patients with type 2 diabetes and diabetic foot ulcers (DFU). A total of 242 participants with type 2 diabetes, mean age 59.1 ± 10 years, mean body mass index 31.4 ± 6.3 kg/m², and estimated glomerular filtration rate ≥45 mL/min/1.73m², were divided into 2 groups: 73 with DFU (35 with and 38 without active infection) and 169 without DFU (106 with diabetic peripheral neuropathy, 63 without complications). Neuropathy was assessed by 10 g monofilament, Rydel-Seiffer 128 Hz tuning fork, and temperature discrimination. Serum 25(OH)D (25-hydroxy vitamin D) was assessed by ECLIA (electro-chemiluminescence immunoassay) method. Median 25(OH)D level was 12.6 ng/mL (IQR [interquartile range] 9.3-17.6 ng/mL) in the studied cohort. The DFU group presented with lower 25(OH)D level as compared with diabetic patients without foot ulcers (non-DFU group): 11.6 ng/mL (IQR 8.5-15.8 ng/mL) versus 13.5 ng/mL (IQR 9.6-18.6 ng/mL), P = .001; the diabetic peripheral neuropathy subgroup demonstrated lower 25(OH)D level in comparison with participants without complications: 12.5 ng/mL (IQR 9-17.2 ng/mL) versus 15.9 ng/mL (IQR 10.4-20.8 ng/mL), P = .031. This remained significantly different even after correction for age and duration of diabetes. There was no difference in 25(OH)D level between the subgroups according to the presence of active infection. In conclusion, vitamin D deficiency may play a role in the development of diabetes complications.

Photo-Optical Transcutaneous Oxygen Tension Measurement Is of Added Value to Predict Diabetic Foot Ulcer Healing: An Observational Study

Currently, transcutaneous oxygen tension measurement (TCpO2) is the most favorable non-invasive test for diabetic foot ulcer (DFU) healing prognosis. Photo-optical TCpO2 is novel, less time-consuming and more practical in use compared to regular electro-chemical TCpO2. We prospectively investigated the clinical value of photo-optical TCpO2 to predict DFU healing. Patients with suspected DFU undergoing conservative treatment underwent an ankle pressure, toe-pressure and photo-optical TCpO2 test. The primary endpoint was DFU wound healing at 12 months. Based on their clinical outcome, patients were divided into a DFU healing and DFU non-healing group. Healing was defined as fully healed ulcers and non-healing as ulcers that deteriorated under conservative treatment or that required surgical amputation. Differences between groups were analyzed and an optimal TCpO2 cut-off value was determined. In total, 103 patients were included, of which 68 patients (66%) were classified as DFU healing. The remaining 35 patients (34%) had deteriorated ulcers, of which 29 (83%) eventually required surgical amputation. An optimal TCpO2 cut-off value of 43 mmHg provided a sensitivity, specificity and odds ratio of 0.78, 0.56 and 4.4, respectively. Photo-optical TCpO2 is an adequate alternative tool to validate the vascular status of the lower extremity indicating healing prognosis in patients with DFU. Therefore, we recommend that photo-optical TCpO2 can be safely coapplied in clinical practice to assist in DFU treatment strategy.

Glycemic control and diabetic foot ulcer outcomes: A systematic review and meta-analysis of observational studies

OBJECTIVE

To evaluate the association between glycemic control (hemoglobin A1C, fasting glucose, and random glucose) and the outcomes of wound healing and lower extremity amputation (LEA) among patients with diabetic foot ulcers (DFUs).

RESEARCH DESIGN AND METHODS

Medline, EMBASE, Cochrane Library, and Scopus were searched for observational studies published up to March 2019. Five independent reviewers assessed in duplicate the eligibility of each study based on predefined eligibility criteria and two independent reviewers assessed risk of bias. Ameta-analysis was performed to calculate a pooled odds ratio (OR) or hazard ratio (HR) using random effects for glycemic measures in relation to the outcomes of wound healing and LEA. Subgroup analyses were conducted to explore potential source of heterogeneity between studies. The study protocol is registered with PROSPERO (CRD42018096842).

RESULTS

Of 4572 study records screened, 60 observational studies met the study eligibility criteria of which 47 studies had appropriate data for inclusion in one or more meta-analyses(n = 12,604 DFUs). For cohort studies comparing A1C >7.0 to 7.5% vs. lower A1C levels, the pooled OR for LEA was 2.04 (95% CI, 0.91, 4.57) and for studies comparing A1C ≥ 8% vs. <8%, the pooled OR for LEA was 4.80 (95% CI 2.83, 8.13). For cohort studies comparing fasting glucose ≥126 vs. <126 mg/dl, the pooled OR for LEA was 1.46 (95% CI, 1.02, 2.09). There was no association with A1C category and wound healing (OR or HR). There was high risk of bias with respect to comparability of cohorts as many studies did not adjust for potential confounders in the association between glycemic control and DFU outcomes.

CONCLUSIONS

Our findings suggest that A1C levels ≥8% and fasting glucose levels ≥126 mg/dl are associated with increased likelihood of LEA in patients with DFUs. A purposively designed prospective study is needed to better understand the mechanisms underlying the association between hyperglycemia and LEA.

Non-Targeted Metabolomic Analysis Reveals Serum Phospholipid Alterations in Patients with Early Stages of Diabetic Foot Ulcer

Diabetic foot ulcer (DFU) is a common complication of type 2 diabetes mellitus (T2DM) characterized by ulcer formation, which can lead to the amputation of lower extremities. However, the metabolic alterations related to this complication are not completely elucidated. Therefore, we carried out a metabolomic analysis of serum samples obtained from T2DM adult patients diagnosed with diabetic foot ulcer in a cross-sectional, observational, and comparative study. Eighty-four volunteers were classified into the following groups: without T2DM (control group, n = 30) and with T2DM and different stages of diabetic foot ulcer according to Wagner-Meggitt classification system: DFU G0 (n = 11), DFU G1 (n = 14), DFU G2 (n = 16), and DFU G3 (n = 13). The non-target metabolomic profile followed by chemometric analysis revealed that lysophosphatidylethanolamine (16:1) could be proposed as key metabolite related to the onset of diabetic foot ulcer; however, this phospholipid was not affected by diabetic foot ulcer progression. Therefore, further studies are necessary to validate these phospholipids as biomarker candidates for the early diagnosis of diabetic foot ulcer in T2DM patients.

Improving clinical outcomes of diabetic foot ulcers by the 3-month self- and family management support programs in Indonesia: A randomized controlled trial study

BACKGROUND AND AIMS

Diabetic foot ulcers are the leading cause of lower extremity amputations, which require more effective prevention. Even though previous nursing studies on diabetic foot ulcers have been well performed, programs implementing self- and family management are limited and even underexplored. Therefore, the purpose of the study was to investigate the effect of 3-month self- and family management support programs on clinical outcomes among Indonesians with diabetic foot ulcers.

METHOD

The randomized controlled trial design was used to answer the research question of the study. A total of 56 eligible participants were enrolled, with 27 in the experimental group and 29 in the control group. The experimental group received self- and family management support programs for three months. Meanwhile, the control group received usual care. Descriptive statistics, multivariate analysis of variance, and Generalized Estimating Equations were used to analyze the data. The significance level was considered at .05 for hypothesis testing.

RESULTS

The study showed that there were statistically significant improvements in self-management, family supports, hemoglobin A1c, and wound size after implemented the programs for three months (p < .05).

CONCLUSIONS

With regard to the result of the study, implementing the 3-month self- and family management support programs improves the patients' and families' abilities to perform diabetic foot ulcer care at home.

Comparative predictive ability of visit-to-visit HbA1c variability measures for microvascular disease risk in type 2 diabetes

BACKGROUND

To assess the associations of various HbA1c measures, including a single baseline HbA1c value, overall mean, yearly updated means, standard deviation (HbA1c-SD), coefficient of variation (HbA1c-CV), and HbA1c variability score (HVS), with microvascular disease (MVD) risk in patients with type 2 diabetes.

METHODS

Linked data between National Cheng Kung University Hospital and Taiwan's National Health Insurance Research Database were utilized to identify the study cohort. The primary outcome was the composite MVD events (retinopathy, nephropathy, or neuropathy) occurring during the study follow-up. Cox model analyses were performed to assess the associations between HbA1c measures and MVD risk, with adjustment for patients' baseline HbA1c, demographics, comorbidities/complications, and treatments.

RESULTS

In the models without adjustment for baseline HbA1c, all HbA1c variability and mean measures were significantly associated with MVD risk, except HVS. With adjustment for baseline HbA1c, HbA1c-CV had the strongest association with MVD risk. For every unit of increase in HbA1c-CV, the MVD risk significantly increased by 3.42- and 2.81-fold based on the models without and with adjustment for baseline HbA1c, respectively. The associations of HbA1c variability and mean measures with MVD risk in patients with baseline HbA1c < 7.5% (58 mmol/mol) were stronger compared with those in patients with baseline HbA1c ≥ 7.5% (58 mmol/mol).

CONCLUSIONS

HbA1c variability, especially HbA1c-CV, can supplement conventional baseline HbA1c measure for explaining MVD risk. HbA1c variability may play a greater role in MVD outcomes among patients with relatively optimal baseline glycemic control compared to those with relatively poor baseline glycemic control.

Mean and variability of annual haemoglobin A1c are associated with high-risk peripheral artery disease

BACKGROUND

Glucose variability is predictive of cardiovascular events and all-cause mortality. However, the association between peripheral artery disease and glucose variability has not been thoroughly investigated. Therefore, the standard deviation of annual haemoglobin A1c was assessed in patients with type 2 diabetes for evaluating the different risks of peripheral artery disease.

METHODS

A total of 4144 patients underwent an evaluation for the ankle-brachial index and the percentage of mean arterial pressure at the ankle. The first haemoglobin A1c record was retrospectively collected from each year until the ankle-brachial index measurement.

RESULTS

The standard deviation of annual haemoglobin A1c was higher in patients with ankle-brachial index ⩽0.90 than in those with ankle-brachial index >0.90 (1.1 ± 0.9% vs 1.0 ± 0.8%, p = 0.009) and was higher in patients with percentage of mean arterial pressure ⩾45% than in those with percentage of mean arterial pressure <45% (1.1 ± 0.8% vs 1.0 ± 0.8%, p = 0.007). A high standard deviation and mean of annual haemoglobin A1c are associated with high-risk peripheral artery disease, which is defined as a combination of ankle-brachial index ⩽0.90, percentage of mean arterial pressure ⩾45% or both (odds ratio = 1.306; 95% confidence interval = 1.057-1.615; p = 0.014).

CONCLUSION

Fluctuation in the haemoglobin A1c value indicates higher risk for peripheral artery disease in patients with type 2 diabetes and poor glucose control.

Association between glucose variation and lower extremity amputation incidence in individuals with type 2 diabetes: a nationwide retrospective cohort study

AIMS/HYPOTHESIS

Elevated glucose level is one of the risk factors for lower extremity amputation (LEA), but whether glycaemic variability confers independent risks of LEA remains to be elucidated. This study aimed to investigate the association between visit-to-visit glycaemic variability and minor and major LEA risks during 8 years of follow-up in type 2 diabetic individuals aged 50 years and older.

METHODS

This retrospective cohort study included 27,574 ethnic Chinese type 2 diabetic individuals aged ≥50 years from the National Diabetes Care Management Program in Taiwan. Glycaemic variability measures were presented as the CVs of fasting plasma glucose (FPG-CV) and of HbA_1c (A_1c-CV). The effect of glycaemic variability on the incidence of LEA events was analysed using Cox proportional hazards models.

RESULTS

After a median follow-up of 8.9 years, 541 incident cases of LEA with a crude incidence density rate of 2.4 per 1000 person-years were observed. After multivariate adjustment, FPG-CV and A_1c-CV were found to be significantly associated with minor LEA, with corresponding HRs of 1.53 (95% CI 1.15, 2.04) and 1.34 (95% CI 1.02, 1.77) for the third tertiles of FPG-CV and A_1c-CV, respectively. In addition, these associations were stronger amongst older adults with longer diabetes duration (≥3 years) than amongst those with shorter duration (<3 years) (p_interaction < 0.01).

CONCLUSIONS/INTERPRETATION

Our study suggests that visit-to-visit variations in HbA_1c and FPG are important predictors of minor LEA amongst older adults with type 2 diabetes, particularly for those with more than 3 years of diabetes duration.

Predictors of Wound Healing Following Revascularization for Chronic Limb-Threatening Ischemia

OBJECTIVES

After surgical or endovascular revascularization, some ischemic lesions will not heal, while some others will heal at a variable period of time from the intervention, indicating a multifactorial interaction between local and systematic "wound healing-promoting" factors. Our objective was to identify predictors of wound healing following revascularization for chronic limb-threatening ischemia (CLTI).

METHODS

A literature review was performed to identify published research concerning clinical, biochemical, and noninvasive methods as predictors of wound healing time and wound-free period after surgical and endovascular revascularization for CLTI.

RESULTS

Our review indicated that potential predictors included local wound factors, wound depth, patient's comorbidities, medications, smoking and alcohol abuse, poor vessel runoff, and direct versus indirect revascularization. Among the clinical biomarkers, platelet-derived growth factor, transforming growth factor β, basic fibroblast growth factor, tumor necrosis factor α, interleukin (IL) 1, and IL-6 have been proposed as potential predictors. Furthermore, the potential of noninvasive microcirculation assessment to predict proper wound healing has been the topic of extensive investigation. Among the novel methods, transcutaneous measurement of oxygen partial pressure, skin perfusion pressure, oxygen-to-see method, indocyanine green fluorescence imaging, and multispectral optoacoustic tomography have shown promising results.

CONCLUSIONS

The risk factor profile of an ischemic lesion in the lower extremities with a delayed/failed healing response, following a successful revascularization, is not fully clarified. Although many predictors have been assessed so far, further research needs to be done to identify the optimal clinical and biochemical indices and the noninvasive technique assessing the microcirculation that is associated with complete wound healing.

To Smoke or Not To Smoke: Cigarettes Have a Negative Effect on Wound Healing of Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) have a complex pathophysiology and require an expert multidisciplinary treatment. There are several, both systemic and local, risk factors for DFUs. A recent meta-analysis of 18 studies has now provided robust evidence on the detrimental effect of smoking on healing of DFUs. Indeed, healing rates were consistently lower among smokers than among nonsmokers. Based on this new evidence, it is reasonable to consider the utility of smoking cessation programs. Incorporation of the latter into the holistic therapeutic strategy for DFUs may be anticipated to improve healing rates, but this remains to be shown.

Association Between Cigarette Smoking and Diabetic Foot Healing: A Systematic Review and Meta-Analysis

The role of smoking for wound healing in patients with diabetic foot has been unclear. This meta-analysis examined the relationship between cigarette smoking and diabetic foot wound healing. Observational studies for the association between smoking and diabetic foot wound healing of patients were systematically searched through PubMed and Wanfang Data, published up to June 2018. Healing rates of wounds were recognized as outcomes. Meta-analysis models were chosen by heterogeneity. A total of 3388 eligible studies were identified, of which 18 met all our inclusion criteria. In the smoking group, healing rate had an average of 62.1%, ranging from 20.0% to 89.6%; in the nonsmoking group, healing rate had an average of 71.5%, ranging from 40.2% to 93.8%. A significant association was found between smoking and the healing of diabetic foot wounds ( z = 3.08; P = .002), with an odds ratio (OR) of 0.70 (95% CI = 0.56-0.88), based on a random-effects model. Meta-regression analyses indicated that the heterogeneity did not come from publication year ( t = -0.50, P = .622) or overall healing rate ( t = 0.16, P = .872). The leave-one-out sensitivity analysis was robust; sensitivity analysis for pooled estimate of adjusted ORs had an OR of 0.20 (95% CI = 0.07-0.56; z = 3.08; P = .002). Subgroup analysis had an OR of 0.62 (95% CI = 0.41-0.95; z = 2.21; P = .027) in retrospective cohort studies and had an OR of 0.75 (95% CI = 0.57-0.99; z = 2.02; P = .043) in prospective cohort studies. Our meta-analysis indicated that smoking had an overall negative effect on the wound healing of diabetic foot individuals. This study provides evidence for the harm of smoking to diabetic foot and may help reduce the medical and economic burden on poor healing of diabetic foot.

Type 2 Diabetes and Glycemic Variability: Various Parameters in Clinical Practice

It has become possible to measure blood glucose levels continuously from 24 h to approximately 2 weeks due to the recent development of relevant devices such as continuous glucose monitoring and flash glucose monitoring systems. This has enabled not only medical professionals but also patients to monitor details of glycemic variability (GV) which was not possible in the past. Details of GV for both short and intermediate periods can now be obtained, and it is important in patient care to appropriately evaluate the data obtained. Types of GV in terms of time frame vary from short-term to long-term. Several studies reported that long-term GV was related to micro- and macro-angiopathies in patients with type 2 diabetes mellitus (T2DM). However, there are still unknown aspects regarding the relationships of various durations of GV with prognosis. Further clinical trials are required to examine the mechanism of GV and to evaluate whether GV can be a valuable therapeutic target in treatment of patients with T2DM.

The Effect of Individualised Glycemic Intervention on Wound Healing Rate in Diabetic Foot Ulcer (The EIGIFU Study)

Objective

To evaluate the association of glycated haemoglobin (HbA_1c) reduction and wound healing in patients with diabetic foot ulcer (DFU).

Methodology

A 12-week prospective, non-controlled, interventional study in suboptimal-controlled T2DM patients with DFU was conducted. Antidiabetic medications were adjusted with the aim of at least 1% in relation to patient’s individualised HbA_1c target. The wound area was determined by using specific wound tracing. The daily wound area healing rate in cm² per day was calculated as the difference between wound area at first visit and the subsequent visit divided by the number of days between the two visits.

Results

19 patients were included in the study. There was a significant HbA_1c reduction from 10.33 %+1.83% to 6.89%+1.4% (p<0.001) with no severe hypoglycaemia. The median daily wound area healing rate was 0.234 (0.025,0.453) cm²/day. There was a strong positive correlation between these two variables (r=0.752, p=0.01). After dividing the patients into four quartiles based on final HbA_1c and comparing the first quartile vs fourth quartile, there was a significant difference in daily wound area healing rates (0.597 vs 0.044 cm²/day, p=0.012).

Conclusion

There was a positive correlation between HbA_1c reduction and wound healing rate in patients with DFU. Although this is an association study, the study postulated the benefits of achieving lower HbA1c on wound healing rate in DFU which require evidence from future randomised controlled studies.