Risk Factors for Major Amputation in Diabetic Foot Ulcer Patients

Incidence and Risk Factors for Amputations in Persons with Diabetes Mellitus: A Retrospective Cohort Study

The aim of this study was to identify and analyze the incidence rate of amputations and their risk factors in people with Diabetes Mellitus (DM) in two specialized outpatient clinics in Brazil. This is an epidemiological, retrospective cohort study using data collected from electronic health records of 281 adult diabetic patient types 1 or 2; attended in specialized outpatient service between 2015 and 2020. Statistical analyses were performed using the 2 sample t-test or Wilcoxon-Mann-Whitney test, for quantitative variables, and the Pearson's χ2 test or Fisher's exact test for categorical variables. The investigation of the risk factors for amputation was carried out through logistic regression. The study was approved by ethical committee. The sample mean age was 65.6 years (SD 13.05), predominating male gender n = 211 (75%), type 2 DM n = 223 (86.7%), with cardiovascular disease n = 143 (63.2%), and about 68.7% (n = 156) with peripheral arterial disease (PAD). Seventy-seven had lower limb amputation (LLA), with a rate incidence of 31.9% during five years. Logistic regression analysis showed the following associations with amputation: Diabetic peripheral neuropathy increased the rate of amputation by 3.6 times (OR = 3.631, 95% CI = 1.214-11.353; P = .022), and peripheral arterial disease increased by 10 times (OR = 10.631; 95% CI = 2.969-57.029; P = .001). The LLA in individuals with DM in two specialized outpatient services was higher compared to international literature; DPN and PAD were confirmed as risk factors for amputation, according to literature. This finding suggests that the study population faces an increased risk of amputation, highlighting the urgent need for targeted interventions and implementing robust preventive strategies to transform the current scenario and mitigate these severe outcomes. A comprehensive approach is essential to proactively address the underlying issues and reduce the prevalence and impact of amputations in Brazil.

Risk Factors Associated with Failure of Toe Amputation in Diabetic Foot Infections

We aim to identify the factors associated with the failure of amputation of one to three toes (index toe amputation) in patients with diabetes and foot infection. We conducted a retrospective cohort of 175 patients with diabetes who were hospitalized for moderate to severe foot infection and underwent amputation of one to three toes. A Poisson regression model was used to determine the prevalence ratio (PR) as a measure of association. The mean age was 63.3 ± 11.4 years. Fifty-three patients presented failure after undergoing toe amputation (30.3%). Multivariate analysis, adjusted for age and sex, showed the following significant variables: severe infection (PR: 1.78; 95% confidence interval [CI]: 1.14-2.78; P = 0.011), infection by Escherichia coli (PR: 2.21; 95% CI: 1.42-3.43; P < 0.001), infection by Pseudomonas aeruginosa (PR: 2.11; 95% CI: 1.29-3.43; P = 0.003) and prothrombin time (PR: 1.13; 95% CI: 1.05-1.21; P = 0.001), obesity (PR: 0.58; 95% CI: 0.37-0.93; P = 0.024), and haemoglobin value (PR: 0.92; 95% CI: 0.86-0.99; P = 0.023). About one-third of patients who underwent amputation of one to three toes for diabetic foot infection presented a failure and required a more proximal surgery. Severe infections, isolation of Pseudomonas aeruginosa and Escherichia coli, and prolonged prothrombin time were associated with a higher prevalence of failure. However, obesity and an elevated haemoglobin level were associated with a lower prevalence of failure.

Wound management, healing, and early prosthetic rehabilitation: Part 2 - A scoping review of physical biomarkers

BACKGROUND

The timely provision of load-bearing prostheses significantly reduces healthcare costs and lowers post-amputation mortality risk. However, current methods for assessing residuum health remain subjective, underscoring the need for standardized, evidence-based approaches incorporating physical biomarkers to evaluate residual limb healing and determine readiness for prosthetic rehabilitation.

OBJECTIVES

This review aimed to identify predictive, diagnostic, and indicative physical biomarkers of healing of the tissues and structures found in the residual limbs of adults with amputation.

METHODOLOGY

A scoping review was conducted following Joanna Briggs Institute (JBI) and PRISMA-ScR guidance. Searches using "biomarkers", "wound healing", and "amputation" were performed on May 6, 2023, on Web of Science, Ovid MEDLINE, Ovid Embase, Scopus, Cochrane, PubMed, and CINAHL databases. Inclusion criteria were: 1) References to physical biomarkers and healing; 2) Residuum tissue healing; 3) Clear methodology with ethical approval; 4) Published from 2017 onwards. Articles were assessed for quality (QualSyst tool) and evidence level (JBI system), and categorized by study, wound, and model type. Physical biomarkers that were repeated not just within categories, but across more than one of the study categories were reported on.

FINDINGS

The search strategy identified 3,306 sources, 157 of which met the inclusion criteria. Histology was the most frequently repeated physical biomarker used in 64 sources, offering crucial diagnostic insights into cellular healing processes. Additional repeated indicative and predictive physical biomarkers, including ankle-brachial index, oxygenation measures, perfusion, and blood pulse and pressure measurements, were reported in 25, 19, 13, and 12 sources, respectively, providing valuable data on tissue oxygenation and vascular health.

CONCLUSION

Ultimately, adopting a multifaceted approach that integrates a diverse array of physical biomarkers (accounting for physiological factors and comorbidities known to influence healing) may substantially enhance our understanding of the healing process and inform the development of effective rehabilitation strategies for individuals undergoing amputation.

Risk Factors Associated with Amputation for Patients with Diabetic Foot Ulcers: A Retrospective Study

Objective

Diabetic foot ulcer (DFU) and related amputation significantly contribute to morbidity rates. The objective of this study was to assess the risk factors correlated with amputation in Chinese patients with DFU.

Methods

A prospective study was implemented on DFU patients at Third Affiliated Hospital of Anhui Medical University from February 2016 to May 2024. Patients were categorized into two groups based on whether they underwent amputation: the amputation group (n = 33) and the non-amputation group (n = 29). A comparative analysis was conducted between two groups, focusing on demographic data, disease characteristics, and laboratory indicators. Binary and multivariate logistic regressions were employed to evaluate the risk factors associated with amputation. Receiver Operating Characteristic curve analysis was used to assess the risk factors in predicting amputation in patients with DFU.

Results

The incidence of history of amputation, duration of diabetes in the amputation group were significantly increased compared to the non-amputation group (P < 0.05). On the contrary, the red blood cell count, hemoglobin level, and hematocrit in the amputation group were significantly lower compared to the non-amputation group (P < 0.05). Moreover, in the bi-variable logistic regression analysis, the duration of diabetes, duration of DFU, history of amputation, and hemoglobin levels were significantly associated with amputation (P < 0.05). After controlling potential confounding factors in multiple logistic regression analysis, duration of DFU was identified as a determining factor for amputation (P < 0.05). Additionally, the values for the area under curve (AUC) in relation to the duration of diabetes, duration of DFU, history of amputation, and a combined panel in predicting the occurrence of amputation in patients with DFU were 0.890, 0.868, 0.730, and 0.916, respectively.

Conclusion

Our findings indicate that duration of DFU is an independent risk factor for amputation in patients with DFU.

Association between tissue loss type and amputation risk among Medicare patients with concomitant diabetes and peripheral arterial disease

OBJECTIVE

Prior studies have described risk factors associated with amputation in patients with concomitant diabetes and peripheral arterial disease (DM/PAD). However, the association between the severity and extent of tissue loss type and amputation risk remains less well-described. We aimed to quantify the role of different tissue loss types in amputation risk among patients with DM/PAD, in the context of demographic, preventive, and socioeconomic factors.

METHODS

Applying International Classification of Diseases (ICD)-9 and ICD-10 codes to Medicare claims data (2007-2019), we identified all patients with continuous fee-for-service Medicare coverage diagnosed with DM/PAD. Eight tissue loss categories were established using ICD-9 and ICD-10 diagnosis codes, ranging from lymphadenitis (least severe) to gangrene (most severe). We created a Cox proportional hazards model to quantify associations between tissue loss type and 1- and 5-year amputation risk, adjusting for age, race/ethnicity, sex, rurality, income, comorbidities, and preventive factors. Regional variation in DM/PAD rates and risk-adjusted amputation rates was examined at the hospital referral region level.

RESULTS

We identified 12,257,174 patients with DM/PAD (48% male, 76% White, 10% prior myocardial infarction, 30% chronic kidney disease). Although 2.2 million patients (18%) had some form of tissue loss, 10.0 million patients (82%) did not. The 1-year crude amputation rate (major and minor) was 6.4% in patients with tissue loss, and 0.4% in patients without tissue loss. Among patients with tissue loss, the 1-year any amputation rate varied from 0.89% for patients with lymphadenitis to 26% for patients with gangrene. The 1-year amputation risk varied from two-fold for patients with lymphadenitis (adjusted hazard ratio, 1.96; 95% confidence interval, 1.43-2.69) to 29-fold for patients with gangrene (adjusted hazard ratio, 28.7; 95% confidence interval, 28.1-29.3), compared with patients without tissue loss. No other demographic variable including age, sex, race, or region incurred a hazard ratio for 1- or 5-year amputation risk higher than the least severe tissue loss category. Results were similar across minor and major amputation, and 1- and 5-year amputation outcomes. At a regional level, higher DM/PAD rates were inversely correlated with risk-adjusted 5-year amputation rates (R2 = 0.43).

CONCLUSIONS

Among 12 million patients with DM/PAD, the most significant predictor of amputation was the presence and extent of tissue loss, with an association greater in effect size than any other factor studied. Tissue loss could be used in awareness campaigns as a simple marker of high-risk patients. Patients with any type of tissue loss require expedited wound care, revascularization as appropriate, and infection management to avoid amputation. Establishing systems of care to provide these interventions in regions with high amputation rates may prove beneficial for these populations.

Risk factors related to amputation in diabetic foot patients: single center outcomes

AIM

This study aimed at identifying factors that worsen the prognosis of diabetic foot, one of the most common complications seen in patients with diabetes.

Enhancing diabetic foot ulcer prediction with machine learning: A focus on Localized examinations

Background

diabetices foot ulcer (DFU) are serious complications. It is crucial to detect and diagnose DFU early in order to provide timely treatment, improve patient quality of life, and avoid the social and economic consequences. Machine learning techniques can help identify risk factors associated with DFU development.

Objective

The aim of this study was to establish correlations between clinical and biochemical risk factors of DFU through local foot examinations based on the construction of predictive models using automated machine learning techniques.

Methods

The input dataset consisted of 566 diabetes cases and 50 DFU risk factors, including 9 local foot examinations. 340 patients with Class 0 labeling (low-risk DFU), 226 patients with Class 1 labeling (high-risk DFU). To divide the training group (consisting of 453 cases) and the validation group (consisting of 113 cases), as well as preprocess the data and develop a prediction model, a Monte Carlo cross-validation approach was employed. Furthermore, potential high-risk factors were analyzed using various algorithms, including Bayesian BYS, Multi-Gaussian Weighted Classifier (MGWC), Support Vector Machine (SVM), and Random Forest Classifier (RF). A three-layer machine learning training was constructed, and model performance was estimated using a Confusion Matrix. The top 30 ranking feature variables were ultimately determined. To reinforce the robustness and generalizability of the predictive model, an independent dataset comprising 248 cases was employed for external validation. This validation process evaluated the model's applicability and reliability across diverse populations and clinical settings. Importantly, the external dataset required no additional tuning or adjustment of parameters, enabling an unbiased assessment of the model's generalizability and its capacity to predict the risk of DFU.

Results

The ensemble learning method outperformed individual classifiers in various performance evaluation metrics. Based on the ROC analysis, the AUC of the AutoML model for assessing diabetic foot risk was 88.48 % (74.44-97.83 %). Other results were found to be as follows: 87.23 % (63.33 %-100.00 %) for sensitivity, 87.43 % (70.00 %-100.00 %) for specificity, 87.33 % (76.66 %-95.00 %) for accuracy, 87.69 % (75.00 %-100.00 %) for positive predictive value, and 87.70 % (71.79 %-100.00 %) for negative predictive value. In addition to traditional DFU risk factors such as cardiovascular disorders, peripheral artery disease, and neurological damage, we identified new risk factors such as lower limb varicose veins, history of cerebral infarction, blood urea nitrogen, GFR (Glomerular Filtration Rate), and type of diabetes that may be related to the development of DFU. In the external validation set of 158 samples, originating from an initial 248 with exclusions due to missing labels or features, the model still exhibited strong predictive accuracy. The AUC score of 0.762 indicated a strong discriminatory capability of the model. Furthermore, the Sensitivity and Specificity values provided insights into the model's ability to correctly identify both DFU cases and non-cases, respectively.

Conclusion

The predictive model, developed through AutoML and grounded in local foot examinations, has proven to be a robust and practical instrument for the screening, prediction, and diagnosis of DFU risk. This model not only aids medical practitioners in the identification of potential DFU cases but also plays a pivotal role in mitigating the progression towards adverse outcomes. And the recent successful external validation of our DFU risk prediction model marks a crucial advancement, indicating its readiness for clinical application. This validation reinforces the model's efficacy as an accessible and reliable tool for early DFU risk assessment, thereby facilitating prompt intervention strategies and enhancing overall patient outcomes.

Multimodal Identification of Molecular Factors Linked to Severe Diabetic Foot Ulcers Using Artificial Intelligence

Diabetic foot ulcers (DFUs) are a severe complication of diabetes mellitus (DM), which often lead to hospitalization and non-traumatic amputations in the United States. Diabetes prevalence estimates in South Texas exceed the national estimate and the number of diagnosed cases is higher among Hispanic adults compared to their non-Hispanic white counterparts. San Antonio, a predominantly Hispanic city, reports significantly higher annual rates of diabetic amputations compared to Texas. The late identification of severe foot ulcers minimizes the likelihood of reducing amputation risk. The aim of this study was to identify molecular factors related to the severity of DFUs by leveraging a multimodal approach. We first utilized electronic health records (EHRs) from two large demographic groups, encompassing thousands of patients, to identify blood tests such as cholesterol, blood sugar, and specific protein tests that are significantly associated with severe DFUs. Next, we translated the protein components from these blood tests into their ribonucleic acid (RNA) counterparts and analyzed them using public bulk and single-cell RNA sequencing datasets. Using these data, we applied a machine learning pipeline to uncover cell-type-specific and molecular factors associated with varying degrees of DFU severity. Our results showed that several blood test results, such as the Albumin/Creatinine Ratio (ACR) and cholesterol and coagulation tissue factor levels, correlated with DFU severity across key demographic groups. These tests exhibited varying degrees of significance based on demographic differences. Using bulk RNA-Sequenced (RNA-Seq) data, we found that apolipoprotein E (APOE) protein, a component of lipoproteins that are responsible for cholesterol transport and metabolism, is linked to DFU severity. Furthermore, the single-cell RNA-Seq (scRNA-seq) analysis revealed a cluster of cells identified as keratinocytes that showed overexpression of APOE in severe DFU cases. Overall, this study demonstrates how integrating extensive EHRs data with single-cell transcriptomics can refine the search for molecular markers and identify cell-type-specific and molecular factors associated with DFU severity while considering key demographic differences.

New Diagnostic and Therapeutic Approaches in Diabetic Microvascular Complications

Diabetes mellitus is a major global health problem with an ascendant trend that makes it expected to reach up to 700 million cases by 2045 [...].

Predictors of amputation in patients with diabetic foot ulcers: a multi-centre retrospective cohort study

PURPOSE

Investigating risk factors for amputation in patients with diabetic foot ulcer (DFU) and developing a nomogram prediction model.

METHODS

We gathered case data of DFU patients from five medical institutions in Anhui Province, China. Following eligibility criteria, a retrospective case-control study was performed on data from 526 patients.

RESULTS

Among the 526 patients (mean age: 63.32 ± 12.14), 179 were female, and 347 were male; 264 underwent amputation. Univariate analysis identified several predictors for amputation, including Blood type-B, Ambulation, history of amputation (Hx. Of amputation), Bacterial culture-positive, Wagner grade, peripheral arterial disease (PAD), and laboratory parameters (HbA1c, Hb, CRP, ALB, FIB, PLT, Protein). In the multivariate regression, six variables emerged as independent predictors: Blood type-B (OR = 2.332, 95%CI [1.488-3.657], p < 0.001), Hx. Of amputation (2.298 [1.348-3.917], p = 0.002), Bacterial culture-positive (2.490 [1.618-3.830], p <0.001), Wagner 3 (1.787 [1.049-3.046], p = 0.033), Wagner 4-5 (4.272 [2.444-7.468], p <0.001), PAD (1.554 [1.030-2.345], p = 0.036). We developed a nomogram prediction model utilizing the aforementioned independent risk factors. The model demonstrated a favorable predictive ability for amputation risk, as evidenced by its area under the receiver operating characteristics (ROC) curve of 0.756 and the well-fitted corrected nomogram calibration curve.

CONCLUSION

Our findings underscore Blood type-B, Hx. Of amputation, Bacterial culture-positive, Wagner 3-5, and PAD as independent risk factors for amputation in DFU patients. The resultant nomogram exhibits substantial accuracy in predicting amputation occurrence. Timely identification of these risk factors can reduce DFU-related amputation rates.

Cognitive dysfunction in diabetes-related foot complications: A cohort study

Objective

Mild-moderate cognitive impairment has been identified in general diabetes, and early evidence indicates cognitive reductions may be more pronounced in those with diabetes-related foot complications (DRFC). Cognitive difficulties may impede treatment engagement and self-management. This requires further explication to optimise patient care and outcomes. The current study aimed to characterise cognitive function in people with DRFC using comprehensive cognitive measures.

Method

This cross-sectional cohort study recruited 80 adult participants (M age  = 63.38, SD = 11.40, range = 30 - 89) from the Royal Melbourne Hospital Diabetic Foot Unit in Victoria, Australia, all with DRFC. Each completed a comprehensive cognitive battery (memory, attention, executive functions) and scores were calculated using age-matched population norms, where available.

Results

On the majority of tasks, DRFC participants performed significantly worse than age-matched norms, with the largest decrements seen in inhibition control, verbal memory, verbal abstract reasoning and working memory. Small to moderate reductions were also seen in visual learning, verbal fluency, processing speed and premorbid functioning. Demographic (lower education, male gender) and clinical factors (higher HbA1c, macrovascular and microvascular disease, longer diabetes duration) were associated with poorer cognitive functioning.

Conclusions

Marked reductions in cognitive functioning were found in individuals with DRFC, predominantly in the domains of verbal memory and executive functioning. Lower education, male gender and indicators of diabetes severity, such as vascular disease, are associated with heightened risk for poorer cognitive functioning. As DRFCs are a serious complication with devastating outcomes if not successfully managed, cognitive barriers to self-management must be addressed to optimise treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01381-4.

Early intervention and care for Diabetic Foot Ulcers in Low and Middle Income Countries: Addressing challenges and exploring future strategies: A narrative review

Background and Aims

Diabetic Foot Ulcers (DFUs) are a significant health concern, particularly in Low- and Middle-Income Countries (LMICs). This review explores key strategies for managing DFUs in LMICs, including integrating podiatry, endocrinology, and wound care services, educating patients, promoting self-care, and preventive measures to reduce amputation rates.

Methods

A comprehensive literature review was conducted, focusing on studies conducted in Low and Middle Income Countries to facilitate a qualitative analysis. The review examined the aetiology and risk factors to developing DFUs, clinical presentation, multidisciplinary management and evidence based interventions, challenges to the provision of care and future directions, all pertaining to DFUs in low and middle income countries.

Results

The aetiology and risk factors contributing to the development of DFUs are complex and multifaceted. Factors such as limited access to health care, inadequate diabetes management, and socioeconomic disparities significantly influence the incidence of DFUs. Clinical presentation varies, with patients often presenting at advanced stages of the disease due to delayed or missed diagnoses. Multidisciplinary management, incorporating podiatry, endocrinology, and wound care services, has exhibited substantial promise in enhancing patient outcomes. Evidence-based interventions, including offloading techniques, wound debridement, and the use of advanced wound dressings, have proven effective in promoting ulcer healing.

Conclusion

The burden of DFUs in LMICs requires comprehensive strategies. Integrating podiatry, endocrinology, and wound care services, along with patient education and self-care practices, is essential for reducing amputations and improving patients' quality of life. Regular follow-up and early detection are vital for effective DFU management, emphasizing the need for ongoing research and investment in LMIC health care infrastructure. Embracing these multidisciplinary, patient-centered approaches can effectively address the challenge of DFUs in LMICs, leading to better patient outcomes and improved quality of life.

Risk Factors for Major Lower Limb Amputation and Effect of Endovascular Revascularization in Patients with Diabetic Foot Wound

Objective

Major lower extremity amputation (LEA) such as below-knee or above-knee amputations can result in more physical disabilities and poorer socioeconomic functions than minor LEAs in diabetic foot ulcer (DFU). Therefore, identification of risk factors for major LEA and investigation of effectiveness of endovascular revascularization are critical for prevention and better prognosis of DFU patients.

Methods

From January 2014 to December 2017, a total of 125 patients with DFU treated with any level of amputation were included in this study. Demographic, diabetes-related, DFU-related and -relevant laboratory information were investigated to predict major amputation. To identify risk factors for major amputation, logistic regression analysis was performed for each variable. The effectiveness of endovascular revascularization treatment was analyzed using Kaplan-Meier survival curves.

Results

Major amputation was performed for 22 of 125 patients. Multivariate logistic regression analysis indicated that DM duration, peripheral arterial occlusive disease (PAOD) previous amputation, abscess, Wagner grade, CRP and albumin were significant risk factors for major amputation in DFU patients. PAOD was the most important risk factor. Major amputation-free survival rate at 5 years was 97.4% in a non-PAOD group, 58.3% in a PAOD without revascularization group, and 88.0% in a PAOD with revascularization group, showing statistically significant differences among them.

Conclusion

The duration of DM, PAOD, previous amputation, abscess, Wagner grade, CRP and albumin were major risk factors for major LEA in DFU patients. The most valuable and critical finding was that revascularization in diabetic foot patients with PAOD significantly improved major amputation-free survival rates.

Classification of foot ulcers in people with diabetes: A systematic review

BACKGROUND

Classification and scoring systems can help both clinical management and audit the outcomes of routine care.

AIM

This study aimed to assess published systems used to characterise ulcers in people with diabetes to determine which should be recommended to (a) aid communication between health professionals, (b) predict clinical outcome of individual ulcers, (c) characterise people with infection and/or peripheral arterial disease, and (d) audit to compare outcomes in different populations. This systematic review is part of the process of developing the 2023 guidelines to classify foot ulcers from the International Working Group on Diabetic Foot.

METHODS

We searched PubMed, Scopus and Web of Science for articles published up to December 2021 which evaluated the association, accuracy or reliability of systems used to classify ulcers in people with diabetes. Published classifications had to have been validated in populations of >80% of people with diabetes and a foot ulcer.

RESULTS

We found 28 systems addressed in 149 studies. Overall, the certainty of the evidence for each classification was low or very low, with 19 (68%) of the classifications being assessed by ≤ 3 studies. The most frequently validated system was the one from Meggitt-Wagner, but the articles validating this system focused mainly on the association between the different grades and amputation. Clinical outcomes were not standardized but included ulcer-free survival, ulcer healing, hospitalisation, limb amputation, mortality, and cost.

CONCLUSION

Despite the limitations, this systematic review provided sufficient evidence to support recommendations on the use of six particular systems in specific clinical scenarios.

Factors associated with diabetic foot ulcers and lower limb amputations in type 1 and type 2 diabetes supported by real-world data from the German/Austrian DPV registry

AIMS

Diabetic foot ulcer (DFU) is a leading cause of lower limb amputations in people with diabetes. This study was aimed to retrospectively analyze factors affecting DFU using real-world data from a large, prospective central-European diabetes registry (DPV [Diabetes-Patienten-Verlaufsdokumentation]).

MATERIALS AND METHODS

We matched adults with type 1 (T1D) or type 2 diabetes (T2D) and DFU to controls without DFU by diabetes type, age, sex, diabetes duration, and treatment year to compare possible risk factors. Cox regression was used to calculate hazard ratios for amputation among those with DFU.

RESULTS

In our cohort (N = 63 464), male sex, taller height, and diabetes complications such as neuropathy, peripheral artery disease, nephropathy, and retinopathy were associated with DFU (all p < .001). Glycated hemoglobin (HbA1c) was related to DFU only in T1D (mean with 95% confidence interval [CI]: 7.8 [6.9-9.0] % vs 7.5 [6.8-8.5] %, p < .001). High triglycerides and worse low-density lipoprotein/high-density lipoprotein ratio were also associated with DFU in T1D, whereas smoking (14.7% vs 13.1%) and alcohol abuse (6.4% vs 3.8%, both p < .001) were associated with DFU in T2D. Male sex, higher Wagner grades, and high HbA1c in both diabetes types and insulin use in T2D were associated with increased hazard ratios for amputations.

CONCLUSIONS

Sex, body height, and diabetes complications were associated DFU risk in adults with T1D and T2D. Improvement in glycemic control and lipid levels in T1D and reduction of smoking and drinking in T2D may be appropriate interventions to reduce the risk for DFU or amputations.

Risk Prediction of Diabetic Foot Amputation Using Machine Learning and Explainable Artificial Intelligence

BACKGROUND

Diabetic foot ulcers (DFUs) are serious complications of diabetes which can lead to lower extremity amputations (LEAs). Risk prediction models can identify high-risk patients who can benefit from early intervention. Machine learning (ML) methods have shown promising utility in medical applications. Explainable modeling can help its integration and acceptance. This study aims to develop a risk prediction model using ML algorithms with explainability for LEA in DFU patients.

METHODS

This study is a retrospective review of 2559 inpatient DFU episodes in a tertiary institution from 2012 to 2017. Fifty-one features including patient demographics, comorbidities, medication, wound characteristics, and laboratory results were reviewed. Outcome measures were the risk of major LEA, minor LEA and any LEA. Machine learning models were developed for each outcome, with model performance evaluated using receiver operating characteristic (ROC) curves, balanced-accuracy and F1-score. SHapley Additive exPlanations (SHAP) was applied to interpret the model for explainability.

RESULTS

Model performance for prediction of major, minor, and any LEA event achieved ROC of 0.820, 0.637, and 0.756, respectively, with XGBoost, XGBoost, and Gradient Boosted Trees algorithms demonstrating best results for each model, respectively. Using SHAP, key features that contributed to the predictions were identified for explainability. Total white cell (TWC) count, comorbidity score and red blood cell count contributed highest weightage to major LEA event. Total white cell, eosinophils, and necrotic eschar in the wound contributed most to any LEA event.

CONCLUSIONS

Machine learning algorithms performed well in predicting the risk of LEA in a patient with DFU. Explainability can help provide clinical insights and identify at-risk patients for early intervention.

Chronic Leg Ulcer Associated with Cutaneous IgG4-Related Disease

Chronic leg ulcer occurs in up to 13% of the general population and leads to economic and health care burdens. Approximately 20% of chronic nonhealing wounds are related to autoimmune diseases or vasculitis. Of these, chronic wounds associated with IgG4-related disease, a group of fibroinflammatory disorders that can have cutaneous and systemic involvement, are rarely reported. This case report describes a chronic leg ulcer associated with cutaneous IgG4-related disease. In addition to disease control with anti-inflammatory agents, following the principles of wound management and providing adjuvant wound treatment (eg, debridement, dressing, photobiomodulation therapy, or hyperbaric oxygen therapy) can promote the wound healing process.

Elevated HbA1c level associated with disease severity and surgical extension in diabetic foot patients

BACKGROUND

Diabetic foot is a complex syndrome that is associated with other diabetic complications, such as peripheral arte-rial disease and peripheral neuropathy. Optimization of plasma glucose and glycated hemoglobin (HbA1c) is one of the main principles of standard care and treatment approaches in individuals with diabetes mellitus (DM). In this study, the relationship of HbA1c level at the time of diagnosis was evaluated with diabetic foot disease severity score and surgical extension in patients with Type 2 DM.

METHODS

This study included 301 consecutive patients who were diagnosed with diabetic foot in the general surgery diabetic foot clinic and were hospitalized for surgery. The relationships between the HbA1c levels of the patients with the Wagner and PEDIS (Perfusion, Extent, Dept, Infection, Sensation) classification system grades, and the surgical procedures performed were analyzed and the treatment outcomes were evaluated.

RESULTS

It was determined that there was a 90% statistically significant relationship between HbA1c values of ≥10.1% and the de-velopment of Wagner Grade 4 diabetic foot ulcer (DFU) (P=0.037). A strong statistically significant relationship at the rate of 85% was determined between HbA1c values of ≥10.1% and the development of PEDIS Grade 3 ulcers. As the HbA1c values increased, so there was determined to be a statistically significant relationship with the development of PEDIS Grade 3 ulcer (P=0.003). In the comparison of the HbA1c values according to the type of surgery performed, a weak relationship was determined at the rate of 26%, and it was determined that as the HbA1c values increased, so there could be an increase in the amputation level.

CONCLUSION

The results of this study showed that as HbA1c values at diagnosis increased in patients with diabetic foot; Wagner/PEDIS grades, disease severity, surgical extension, amputation level, and tissue loss increased. To reduce the severity of diabetic foot disease and prevent amputation, compliance with diabetic treatment and glycemic control should be increased.

Risk Factors for Failure After Surgery in Patients With Diabetic Foot Syndrome

Background

In the present study, we aimed to identify risk factors for failure (defined as reoperation within 60 days) after debridement or amputation at the lower extremity in patients with diabetic foot syndrome and to develop a model using the significant risk factors to predict the success rate at different levels of amputation.

Methods

Between September 2012 and November 2016, we performed a prospective observational cohort study of 174 surgeries in 105 patients with diabetic foot syndrome. In all patients, debridement or the level of amputation, need for reoperation, time to reoperation, and potential risk factors were assessed. A cox regression analysis, dependent on the level of amputation, with the endpoint reoperation within 60 days defined as failure and a predictive model for the significant risk factors were conducted.

Results

We identified the following 5 independent risk factors: More than 1 ulcer (hazard ratio [HR] 3.8), peripheral artery disease (PAD, HR 3.1), C-reactive protein >100 mg/L (HR 2.9), diabetic peripheral neuropathy (HR 2.9), and nonpalpable foot pulses (HR 2.7) are the 5 independent risk factors for failure, which were identified. Patients with no or 1 risk factor have a high success rate independent of the level of amputation. A patient with up to 2 risk factors undergoing debridement will achieve a success rate of <60%. However, a patient with 3 risk factors undergoing debridement will need further surgery in >80%. In patients with 4 risk factors a transmetatarsal amputation and in patients with 5 risk factors a lower leg amputation is needed for a success rate >50%.

Conclusion

Reoperation for diabetic foot syndrome occurs in 1 of 4 patients. Risk factors include presence of more than 1 ulcer, PAD, CRP > 100, peripheral neuropathy, and nonpalpable foot pulses. The more risk factors are present, the lower the success rate at a certain level of amputation.

Level of Evidence

Level II, prospective observational cohort study.

Clinical presentation of group B Streptococcus-infected diabetic foot ulcers

OBJECTIVE

Group B Streptococcus (GBS) is a common pathogen in diabetic foot ulcers (DFUs), where it has been found to result in higher rates of soft tissue infection and amputation despite appropriate treatment. In this study, we aim to investigate clinical characteristics and prognosis of GBS DFU infections, especially those with tenosynovial involvement. We hypothesise that GBS-infected DFUs with tenosynovial involvement leads to an increased number of recurrent infections and unexpected returns to the operating room.

METHOD

Data were retrospectively collected from GBS-infected DFU patients surgically treated by an orthopaedic foot and ankle surgeon over a four-year period. Demographics, comorbidities, initial laboratory values and culture results from infected bone samples were recorded. Clinical outcome was assessed by recurrent infection and unplanned reoperation(s) within 3 months following the initial surgery.

RESULTS

In total, 72 patients were treated for GBS-infected DFUs. Intra-operative culture of infected bone identified GBS in 16 patients (22.2%). Significantly more black patients (p=0.017) were afflicted by GBS DFUs. Patients with GBS DFUs had higher initial haemoglobin A1C levels (p=0.019), and those with tenosynovial involvement were likely to require reoperation (p=0.036) and had a greater total number of surgeries (p=0.015) than those without.

CONCLUSION

GBS-infected DFUs are more common in black patients and those with elevated haemoglobin A1Cs. GBS infections with tenosynovial involvement are particularly destructive and require aggressive treatment by surgeons.

Prevalence and determinants of lower extremity amputations among type I and type II diabetic patients: A multicenter-based study

The incidence of diabetes-related lower-extremity complications is increasing globally, yet the condition in developing countries, particularly those in sub-Saharan Africa, is unclear. This study determined the prevalence and determinants of lower extremity amputations among type I and type II diabetic patients at health facilities in the Volta Region, Ghana. This was a multicenter-based study involving 473 diabetic patients. Sociodemographic, lifestyle, medical, biochemical, and anthropometric data were obtained systematically with a pretested structured questionnaire. The prevalence rate of lower extremity amputations (LEAs) was 1.9%. LEAs were linked to the male gender (unadjusted odds ratio [UOR] = 5.86; 95% confidence interval [CI] = 1.44-23.82; P = 0.013), smokers (UOR = 10.12; 95% CI = 2.63-38.91; P = .001), type I diabetic patients (UOR = 4.74; 95% CI = 1.24-18.10; P = .023), family history of diabetes mellitus (UOR = 9.18; 95% CI = 2.25-37.46; P = .002), diabetic foot ulcers (adjusted odds ratio [AOR] = 8.62; 95% CI = 1.58-47.62; P = .013) and obesity (AOR = 6.20; 95% CI = 1.00-38.04; P = .049). This study showed a relatively low prevalence rate compared to previous studies within Ghana. However, it is a major concern in public health that needs to be addressed since diabetes-related LEAs are connected to global major morbidity and mortality.

Clinical characteristics and risk factors of lower extremity amputation in the diabetic inpatients with foot ulcers

OBJECTIVES

To analyze clinical characteristics of the diabetic inpatients with foot ulcers and explore the risk factors of lower extremity amputation (LEA) in West China Hospital of Sichuan University.

METHODS

A retrospective analysis was performed based on the clinical data of the patients with diabetic foot ulcer (DFU) hospitalized in West China Hospital of Sichuan University from January 1, 2012 to December 31, 2020. The DFU patients were divided into three groups: non-amputation, minor amputation, and major amputation groups. The ordinal logistic regression analysis was used to identify the risk factors for LEA.

RESULTS

992 diabetic patients (622 males and 370 females) with DFU were hospitalized in the Diabetic Foot Care Center of Sichuan University. Among them, 72 (7.3%) (55 minor amputations and 17 major amputations) cases experienced amputation, and 21(2.1%) refused amputation. Excluding the patients who refused amputation, the mean age and duration of diabetes of and HbA1c the 971 patients with DFU, were 65.1 ± 12.3 years old, 11.1 ± 7.6 years, and 8.6 ± 2.3% respectively. The patients in the major amputation group were older and had longer course of diabetes for a longer period of time than those in the non-amputation and minor amputation groups. Compared with the non-amputation patients (55.1%), more patients with amputation (minor amputation (63.5%) and major amputation (88.2%)) suffered from peripheral arterial disease (P=0.019). The amputated patients had statistically lower hemoglobin, serum albumin and ankle brachial index (ABI), but higher white blood cell, platelet counts, fibrinogen and C-reactive protein levels. The patients with amputation had a higher incidence of osteomyelitis (P = 0.006), foot gangrene (P < 0.001), and a history of prior amputations (P < 0.001) than those without amputation. Furthermore, a history of prior amputation (odds ratio 10.194; 95% CI, 2.646-39.279; P=0.001), foot gangrene (odds ratio 6.466; 95% CI, 1.576-26.539; P=0.010) and ABI (odds ratio 0.791; 95% CI, 0.639-0.980; P = 0.032) were significantly associated with LEAs.

CONCLUSIONS

The DFU inpatients with amputation were older with long duration of diabetes, poorly glycemic control, malnutrition, PAD, severe foot ulcers with infection. A history of prior amputation, foot gangrene and a low ABI level were the independent predictors of LEA. Multidisciplinary intervention for DFU is essential to avoid amputation of the diabetic patients with foot ulcer.

Foot Osteomyelitis Location and Rates of Primary or Secondary Major Amputations in Patients With Diabetes

BACKGROUND

Diabetic foot osteomyelitis (DFO) often leads to amputations in the lower extremity. Data on the influence of the initial anatomical DFO localization on ultimate major amputation are limited.

METHODS

In this retrospective analysis, 583 amputation episodes in 344 patients (78 females, 266 males) were analyzed. All received a form of amputation in combination with antibiotic therapy. A multivariate logistic regression analysis with the primary outcome "major amputation" defined as an amputation above the ankle joint was performed. The association of risk factors including location of DFO, coronary artery disease, peripheral artery disease, neuropathy, nephropathy, and Charcot neuro-osteoarthropathy was analyzed.

RESULTS

Among 583 episodes, DFO was located in the forefoot in 512 (87.8%), in the midfoot in 43 (7.4%), and in the hindfoot in 28 episodes (4.8%). Overall, 53 of 63 (84.1%) major amputations were performed because of DFO in the setting of peripheral artery disease as primary indication. Overall, limb loss occurred in 6.1% (31/512) of forefoot, 20.9% (9/43) of midfoot, and 46.4% (13/28) of hindfoot DFO. Among these, 22 (41.5%) were performed as the primary treatment, whereas 31 (58.5%) followed previously failed minor amputations. Among this latter group of secondary major amputations, the DFO was localized to the forefoot in 23 of 583 (3.9%), the midfoot in 4 of 583 (0.7%) and the hindfoot in 4 of 583 (0.7%). In multivariate logistic regression analysis, initial hindfoot localization was a significant factor (P < .05), whereas peripheral artery disease, smoking, and a midfoot DFO were not found to be risk factors.

CONCLUSION

In our retrospective series, the frequency of limb loss in DFO increased with more proximal initial foot DFO lesions, with almost half of patients losing their limbs with a hindfoot DFO.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

Microbiome Characterization of Infected Diabetic Foot Ulcers in Association With Clinical Outcomes: Traditional Cultures Versus Molecular Sequencing Methods

Background

Infected diabetic foot ulcers (IDFU) are a major complication of diabetes mellitus. These potentially limb-threatening ulcers are challenging to treat due to impaired wound healing characterizing diabetic patients and the complex microbial environment of these ulcers.

Aim

To analyze the microbiome of IDFU in association with clinical outcomes.

Methods

Wound biopsies from IDFU were obtained from hospitalized patients and were analyzed using traditional microbiology cultures, 16S rRNA sequencing and metagenomic sequencing. Patients’ characteristics, culture-based results and sequencing data were analyzed in association with clinical outcomes.

Results

A total of 31 patients were enrolled. Gram-negative bacteria dominated the IDFU samples (79%, 59% and 54% of metagenomics, 16S rRNA and cultures results, respectively, p<0.001). 16S rRNA and metagenomic sequencing detected significantly more anaerobic bacteria, as compared to conventional cultures (59% and 76%, respectively vs. 26% in cultures, p=0.001). Culture-based results showed that Staphylococcus aureus was more prevalent among patients who were treated conservatively (p=0.048). In metagenomic analysis, the Bacteroides genus was more prevalent among patients who underwent amputation (p<0.001). Analysis of metagenomic-based functional data showed that antibiotic resistance genes and genes related to biofilm production and to bacterial virulent factors were more prevalent in IDFU that resulted in amputation (p<0.001).

Conclusion

Sequencing tools uncover the complex biodiversity of IDFU and emphasize the high prevalence of anaerobes and Gram-negative bacteria in these ulcers. Furthermore, sequencing results highlight possible associations among certain genera, species, and bacterial functional genes to clinical outcomes.

The role of CXCL8 in chronic nonhealing diabetic foot ulcers and phenotypic changes in fibroblasts: a molecular perspective

INTRODUCTION

A persistent inflammation is perpetuated by infiltrating immune cells and cytokines secreted from these immune cells. Additionally, apoptotic keratinocytes and adipocytes in diabetes causes diabetic foot ulcer (DFU) to arrest in an inflammatory phase without progressing to the resolution phase. This leads to a nonhealing DFU and, despite advanced treatments consisting of wound debridement, off-loading the ulcer of necrotic tissue, wound dressings to keep it moist and control exudate, medication, and preventing infection, DFUs remain a clinical problem. Nonhealing DFUs pose not only an economic burden but also increased morbidity and mortality in the form of psychological stress with and increased chance of amputation, and even death. Thus, investigating the complicated underlying molecular mechanism responsible for nonhealing patterns and designing better therapeutics is warranted. This review article focuses on the role of IL-8-mediated persistent inflammation and phenotypic change of fibroblasts due to this inflammatory cascade. We have discussed various sources of interleukin (IL)-8 secretion and the possible association of IL8-fibroblast plasticity as a cause of nonhealing DFUs.

MATERIAL AND METHODS

A literature search on PubMed, Google Scholar, and PMC was done including the terms diabetic foot ulcer, diabetes, diabetic ulcer, chronic inflammation, interleukin 8, diabetic wound, and nonhealing diabetic foot ulcers. The articles in the English language and published in last 10 years were selected. From the pool of these, the articles describing the relationship between IL-8 and nonhealing diabetic foot ulcer and diabetic ulcer were used sorted out and used for this review article following PRISMA guidelines.

CONCLUSION

Increased infiltration of inflammatory immune cells, secretion of pro-inflammatory cytokines, altered keratinocyte-fibroblast function, and phenotypic changes of fibroblasts in DFUs seem to be critical to the nonhealing of DFUs. Thus, inhibiting IL-8 secretion and downstream signaling seems to be a goal of potential therapeutics.

Association of continuous glucose monitoring-derived time in range with major amputation risk in diabetic foot osteomyelitis patients undergoing amputation

OBJECTIVE

The metrics generated from continuous glucose monitoring (CGM), such as time in range (TIR), are strongly correlated with diabetes complications. This study explored the association of perioperative CGM-derived metrics with major amputation risk in patients with diabetic foot osteomyelitis (DFO).

METHODS

This study recruited 55 DFO patients with grade 3-4 wounds according to the Wagner Diabetic Foot Ulcer Classification System, all of whom underwent CGM for 5 days during the perioperative period. The CGM-derived metrics were defined in accordance with the most recent international consensus recommendations.

RESULTS

Patients with major amputation had significantly less TIR and higher time below range (TBR) (all p < 0.05). In binary logistic regression analyses, a lower TIR was associated with the risk of major amputation (odds ratio: 0.83 (95% confidence interval: 0.71-0.99), p = 0.039). This association remained statistically significant after adjustments for age, sex, body mass index, type of diabetes, smoking, drinking, durations of diabetes and DFU, ankle-brachial index, albumin, estimated-glomerular filtration rate, Society for Vascular Surgery wound, ischemia, and foot infection (WIfi) stage, multidrug-resistant organisms, and hemoglobin A1c. Further adjustment for the mean amplitude of glycemic excursion (MAGE) reduced this association. TBR was also independently associated with the risk of major amputation (odds ratio: 1.60 (95% confidence interval: 1.17-2.18), p = 0.003); this association persisted after adjustment for MAGE.

CONCLUSION

Perioperative TIR (3.9-10.0 mmol/L) and TBR (<3.9 mmol/L) were significantly associated with major amputation in hospitalized patients with DFO.

Treatment Failures in Diabetic Foot Osteomyelitis Associated with Concomitant Charcot Arthropathy: The Role of Underlying Arteriopathy

OBJECTIVE

Therapy for diabetic foot osteomyelitis (DFO) with Charcot neuroosteoarthropathy is challenging. In patients with diabetic Charcot osteomyelitis (DCO), both the anatomic deformity and infection must be addressed. This study assessed the outcomes of DCO therapy and variables associated with treatment failure and compared them with outcomes of DFO cases.

METHODS

A single-center, retrospective, case-control study was performed to compare 93 DCO episodes with 530 DFO episodes, using Kaplan-Meier survival curves and multivariate Cox regression analyses.

RESULTS

Clinical failure occurred in 21.5% of DCO compared with 22.3% in DFO episodes (p=0.89) and was associated with peripheral arterial disease (PAD) stages 3 or 4 (HR 6.1; CI 2.0-18.1) and chronic treatment with immunosuppressives (HR 7.4; CI 2.0-27.1). Major amputations were significantly more frequent in DCO (28% versus 13.6%; p<0.01) and associated with PAD stages 3 and 4 (HR 8.0; CI 2.2-29.4), smoking (HR 5.4; CI 1.2-24.6), alcohol abuse (HR 3.5; CI 1.1-10.6), and renal dialysis (HR 4.9; CI 1.3-18.9).

CONCLUSIONS

Clinical treatment failures did not differ between DCO and DFO. However, patients with DCO underwent major amputation twice as often as those with DFO. Unlike widespread belief, treatment failure in DCO patients may, similar to DFO, be associated with a striking epidemiological link to severe PAD.