Lower Extremity Amputation In Patients Research Articles

A tool to predict the risk of lower extremity amputation in patients starting dialysis.

Non-traumatic lower extremity amputation (LEA) is a severe complication during dialysis. To inform decision-making for physicians, we developed a multivariable prediction model for LEA after starting dialysis. Data from the Swedish Renal Registry (SNR) between 2010 and 2020 were geographically split into a development and validation cohort. Data from NECOSAD between 1997 and 2009 were used for validation targeted at Dutch patients. Inclusion criteria were no previous LEA and kidney transplant and age≥40 years at baseline. A Fine-Gray model was developed with LEA within 3 years after starting dialysis as outcome of interest. Death and kidney transplant were treated as competing events. One coefficient, ordered by expected relevance, per 20 events was estimated. Performance was assessed with calibration and discrimination. SNR was split into an urban development cohort with 4771 individuals experiencing 201 (4.8%) events and a rural validation cohort with 4.876 individuals experiencing 155 (3.2%) events. NECOSAD contained 1658 individuals experiencing 61 (3.7%) events. Ten predictors were included: female sex, age, diabetes mellitus, peripheral artery disease, cardiovascular disease, congestive heart failure, obesity, albumin, haemoglobin and diabetic retinopathy. In SNR, calibration intercept and slope were -0.003 and 0.912 respectively. The C-index was estimated as 0.813 (0.783-0.843). In NECOSAD, calibration intercept and slope were 0.001 and 1.142 respectively. The C-index was estimated as 0.760 (0.697-0.824). Calibration plots showed good calibration. A newly developed model to predict LEA after starting dialysis showed good discriminatory performance and calibration. By identifying high-risk individuals this model could help select patients for preventive measures.

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

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. 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. 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. 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.

The Effect of Limb Salvage Efforts in Different Age Groups: Relationships Between Major and Minor Amputations

“Limb salvage” efforts, such as performing minor amputations before infections spread proximally from the foot to decrease major lower extremity amputation, are an important part of healthcare today. It is unclear whether these efforts are preventing the number of major amputations and improving patients’ quality of life and the cost-effectiveness of the U.S. healthcare system. Rates of non-traumatic lower extremity amputation (NLEA) among patients with diabetes decreased in the early 2000s but rebounded in the 2010s. We analyzed the proportion of major amputations and differences in amputation rates between age groups in Texas. Patient data was extracted from the Texas Hospital Discharge Data Public Use Data File. Population estimates were obtained from the Texas Population Estimates Program from 2011 to 2015 and from intercensal estimates provided by the U.S. Census Bureau from 2006 to 2010. Raw numbers of minor, major, and all NLEA surgeries and the ratio of major amputations to total amputations per year were reported for each age group. Poisson regression and Joinpoint analyses were performed to capture these changes in trends. Rates of amputations increased, with significant decreasing relative prevalence of major amputations. Patients aged 45 to 64 with diabetes are likely driving these increases. Rates of lower extremity amputation in patients with diabetes increased from 2009 to 2015. This holds for all and minor amputations. In contrast, the ratio of major to all amputations decreased from 2010. Utilization of major and minor amputation differs between age groups, remaining stable in the youngest subjects, with minor amputation rates increasing in those aged 45 to 64.

Risk Factors for Lower Extremity Amputation in Patients with End-Stage Kidney Disease: A Nationwide Cohort Study.

Individuals with end-stage kidney disease (ESKD) on dialysis are at a high risk of developing foot ulcerations and undergoing subsequent lower extremity amputation (LEA), which can exert significant impacts on their quality of life and contribute to rising healthcare costs. We aimed to identify risk factors associated with LEA in patients with ESKD to predict LEA progression and eventually prevent it. We used 18 years (2002-2019) of data from the Korean National Health Insurance Service (KNHIS). Data were collected from patients with ESKD who underwent renal replacement therapy (RRT) and had no history of amputation caused by trauma or toxins. The risk factors were compared between patients with or without LEA. We collected data from 220,838 patients newly diagnosed with ESKD, including 6348 in the LEA group and 214,490 in the non-LEA group. The total incidence of LEA was 2.9%. Older age, male gender, lower income, non-metropolitan residence, diabetes mellitus, dialysis treatment (compared to kidney transplantation), microvascular disease, peripheral vascular disease, endovascular procedure, and endovascular operation were associated with an increased risk of LEA. Thus, individuals with ESKD who are at a higher risk for LEA should be closely monitored, and kidney transplantation should be considered as a preventative measure.

Effectiveness of incisional negative pressure wound therapy after major lower extremity amputation: a randomised controlled trial.

The aim was to study the effect of incisional negative pressure wound therapy (iNPWT) in wound healing compared with standard sterile gauze dressings after major lower extremity amputation in patients with peripheral arterial disease (PAD). This prospective, randomised controlled trial included 50 patients undergoing major lower extremity amputations for PAD. Patients were randomised into iNPWT and standard dressing groups. The patency of blood vessels at the level of the stump was ensured with or without revascularisation. The primary outcome was wound-related complications such as surgical site infection (SSI), wound dehiscence, seroma/haematoma formation or the need for revision amputation. The secondary outcome was the time taken for the eligibility of prosthesis placement. It was found that only 12% of the patients in the iNPWT group had SSI compared with 36% in the standard dressing group (p = 0.047). Rates of wound dehiscence, seroma/haematoma formation and revision amputation were decreased in the iNPWT group but this was not statistically significant (p > 0.05). There was a significant reduction in the time taken for eligibility of prosthesis placement in the iNPWT group (5.12 ± 1.53 vs 6.8 ± 1.95 weeks, p = 0.002). iNPWT is effective in reducing the incidence of SSI and the time taken for rehabilitation in patients undergoing major lower limb amputation due to PAD.

Glucagon-like peptide-1 treatment reduces the risk of diabetes-type 2 related amputations: A cohort study in Denmark

AimsTo assess the impact of Glucagon-like peptide-1 (GLP-1) agonists on the risk of lower extremity amputations in patients with type 2 diabetes mellitus (DM2). MethodsWe conducted a cohort study on 309,116 patients with DM2 using Danish National Register and Diabetes Database. We tracked the GLP-1 agonists over time along with the medication dose. Time-varying models are used to assess the risk of amputation for patients with/without GLP-1 treatment. ResultsPatients on GLP-1 treatment experience a notable reduction in the risk of amputation compared to those without the treatment with a hazard ratio (HR) of 0.5, 95% CI [0.54–0.74], indicating a statistically significant difference (p <.005). This risk reduction was consistent across different age groups, but notably most pronounced among middle income patients. The findings were further validated by using time-varying Cox models, which considered the patient’s comorbidity history. ConclusionsOur analysis reveals compelling evidence of a reduced risk of amputation among patients receiving GLP-1 therapy, an effect dominated by liraglutide, compared to those without the treatment, even after adjusting for various socio-economic factors. However, further investigation is required to identify and account for any other potential confounding variables that may impact the outcome.

Upstream comprehensive management of individuals with diabetes with multimorbidity and frailty to act against amputation

This manuscript constitutes a commentary on: “Retrospective cohort study of long-term outcomes and prognostic factors for survival after lower extremity amputation in patients with diabetes” by Vuorlaakso et al. (2023). We aim to contribute to the reflection of their findings to support the comprehensive management of vulnerable individuals with multimorbidity and/frailty for limb preservation. There is an urgent need to understand the effects of frailty on overall survival after amputation, survival without major amputation, and the effect modification with multimorbidity.

Diabetes-Related Lower Extremity Amputations in Romania: Patterns and Changes between 2015 and 2019

Lower extremity amputations (LEAs) are a feared complication of diabetes mellitus (DM). Here we evaluated the recent trends in DM-related LEAs in Romania. We collected data from a national database regarding minor and major LEAs performed between 2015 and 2019 in patients with DM admitted to a public hospital. Absolute numbers of LEAs were presented by year, diabetes type, sex and age; incidence rates of LEAs in the general population were also calculated. Over the study period, 40,499 LEAs were recorded nationwide (83.16% in persons with type 2 DM [T2DM]); on average, the number of LEAs increased by 5.7%/year. This trend was driven by an increased number of LEAs in patients with T2DM; in patients with type 1 DM (T1DM), LEAs decreased over the study period. In patients with T2DM, the increase in minor LEAs was more pronounced than that in major LEAs. The overall number of LEAs showed an increasing trend with age (r = 0.72), which was most pronounced in patients aged ≥70 years. Men had a higher frequency of LEAs than women, regardless of DM type. These data support renewed efforts to prevent and decrease the burden of amputations among patients with DM.

Analysis of the factors affecting mortality after non-traumatic major lower extremity amputations.

The aim of this study was to evaluate the prognostic factors affecting mortality after major lower extremity amputations in patients with diabetes mellitus and peripheral vascular disease. For this retrospective study, 484 patients (345 male, 139 female) who were previously diagnosed with diabetes mellitus and peripheral vascular disease and underwent first-time nontraumatic major lower extremity amputations between January 2008 and January 2021 were included. The mean age of the patients was 64.2 ± 13.8 (20-114). In 32.4% of patients, peripheral vascular disease was the underlying cause, whereas diabetes mellitus was responsible for the etiology in 67.6% of patients. About 68.8% of patients had below-knee amputations, whereas 2.9% had bilateral below-knee amputations, 27.1% had above-knee amputations, and 1.2% had hip disarticulation performed. Gender, age, amputation level, amputation etiologies, Charlson comorbidity index, need for blood transfusion, and laboratory findings such as hemoglobin, platelet, albumin, erythrocyte sedimentation rate, C-reactive protein, sodium, potassium, and neutrophil to lymphocyte ratio levels were recorded preoperatively and at the time of discharge. Patients were grouped as died ≤1 month, ≤3 months, ≤6 months, and ≤12 months or alive. Advanced age, female gender, high Charlson comorbidity index, blood transfusion requirement, proximal amputation level, preoperative low platelet, preoperative low albumin, and parameters such as low hemoglobin, low erythrocyte sedimentation rate, high sodium, low platelet, low albumin, high C-reactive protein, and high neutrophil to lymphocyte ratio at time of discharge were seen to have a statistically significant effect on mortality at 1 month, 3 months, 6 months, and 12 months postoperatively. Preoperative high C-reactive protein had a statistically significant effect on mortality at 1 and 3 months postoperatively, whereas low C-reactive protein had a statisti cally significant effect on mortality at 6 months postoperatively. High potassium at the time of discharge was associated with mortality at 6 and 12 months postoperatively. This study has shown us that mortality rates are affected by modifiable parameters at the time of discharge such as hemoglo bin, sodium, potassium, platelet, and albumin, and normalization of these parameters before discharge could reduce the rates of mortality in the postoperative period. Level IV, Prognostic Study.

Retrospective cohort study of long-term outcomes and prognostic factors for survival after lower extremity amputation in patients with diabetes

AimsLower extremity amputation (LEA) is a pivotal event for patients with diabetes. This study aimed to provide updated data on the outcomes and prognostic factors after LEA for patients with diabetes. MethodsThis retrospective cohort study included all LEAs (n = 1081) performed at Tampere University Hospital between February 2007 and September 2020. Overall survival (OS) and major amputation-free survival were evaluated. ResultsIndex amputation level was below ankle in 65 % (n = 704) of patients, below knee in 14 % (n = 154) of patients, and above knee in 21 % (n = 223) of patients. In the whole population, OS was 75.8 % (CI 95 %: 73.3–78.3) at one year and 38.3 % (CI 95 %: 34.7–41.7) at five years. Higher age, peripheral artery disease (PAD), more proximal amputation level, and lower glomerular filtration rate (GFR) reduced OS. Multiple amputations and diagnosed dyslipidemia or hypertension associated with improved OS. Further, age, PAD, and GFR were identified as significant factors for major amputation free survival. ConclusionsOS after LEA is poor. After major amputation, the risk for death is higher compared to minor amputation. Recurrent amputation is associated with improved OS. Further, ischemia and renal disease are significant factors for inferior OS.

Comorbidity and risk factors of subsequent lower extremity amputation in patients diagnosed with diabetes in Saskatchewan, Canada.

Subsequent limb amputation (SLA) may be necessary due to disease progression, infection, or to aid prosthesis fit. SLA in Saskatchewan has increased 3.2% from 2006 to 2019 with minor SLA increasing 9.6% during that period. Diabetes affects a large proportion of patients who require SLA; however, the impact of additional comorbidities is not clear. First-episode subsequent lower extremity limb amputation (SLEA) cases with the presence/absence of diabetes, other comorbidities, and demographic characteristics from 2006-2019 were retrieved from Saskatchewan's Discharge Abstract Database. Logistic regression was performed to examine the magnitude of the odds of SLEA. Among the 956 first-episode SLEA patients investigated, 78.8% were diagnosed with diabetes. Of these, 76.1% were male and 83.0% were aged 50 + years. Three comorbidities: renal failure (AOR = 1.9, 95% Cl 1.1 - 3.0), hypertension (AOR = 3.0, 95% Cl 2.0 - 4.5), and congestive heart failure (AOR = 2.0, 95% CI 1.2 - 3.2), conferred the highest odds of SLEA. The odds of SLEA is greatest for those aged 50-69 years, males, Registered Indians, and associated with a prolonged hospital stay. These data are important as they may help medical providers identify patients at the highest risk of SLEA and target interventions to optimize outcomes.

Association among Current Smoking, Alcohol Consumption, Regular Exercise, and Lower Extremity Amputation in Patients with Diabetic Foot: Nationwide Population-Based Study.

The present study investigates whether modifiable behavioral factors of current cigarette smoking, heavy alcohol consumption, and regular exercise are associated with risk of lower extremity amputation (LEA) in diabetic patients. A total of 2,644,440 diabetic patients (aged ≥20 years) was analyzed using the database of the Korean National Health Insurance Service. Cox proportional hazard regression was used to assess adjusted hazard ratios (HRs) for the behavioral factors with risk of LEA under adjustment for potential confounders. The risk of LEA was significantly increased by current cigarette smoking and heavy alcohol consumption (HR, 1.436; 95% confidence interval [CI], 1.367 to 1.508 and HR, 1.082; 95% CI, 1.011 to 1.158) but significantly decreased with regular exercise (HR, 0.745; 95% CI, 0.706 to 0.786) after adjusting for age, sex, smoking, alcohol consumption, exercise, low income, hypertension, dyslipidemia, body mass index, using insulin or oral antidiabetic drugs, and diabetic duration. A synergistically increased risk of LEA was observed with larger number of risky behaviors. Modification of behaviors of current smoking, heavy alcohol intake, and exercise prevents LEA and can improve physical, emotional, and social quality of life in diabetic patients.

Can Sociodemographic Factors be Used to Help Predict Outcomes in Charcot Neuroarthropathy?

Category: Diabetes; Other Introduction/Purpose: The diabetic Charcot foot, or Charcot neuroarthropathy, is a devastating condition that arises secondary to longstanding diabetes, peripheral neuropathy, and trauma. One of the many challenges associated with the Charcot patient is the lack of data exploring factors that may predict long-term outcomes. Therefore, the purpose of this study was to evaluate how certain sociodemographic factors may influence mortality and the need to undergo lower extremity amputation in patients with Charcot. Methods: Following institutional board approval, all patients from 2015-2021 with a diagnosis of Charcot Foot were queried using hospital electronic medical records. Demographics collected included sex, age, race, and insurance coverage. Outcomes recorded were the need to undergo major amputation and mortality rate. Statistical analysis was then run to determine if sex, age, race, and insurance coverage was associated with increased risk of needing a major amputation or death. Results: From 2015-2021, 80 Charcot patients with a mean age of 60 (Range, 84-32) were identified. Of these patients, 58 were male, 26 were female, 71 were white, 3 were African American, and 6 were identified as other. In our cohort, 47 patients had government funded insurance and 33 had private insurance. Amputation occurred in 22 patients and death in 15. Government funded insurance (RR: 9.8, 95% CI:1.4-71.1, P = 0.0236) and age over 65 was associated with an increased risk of death (RR: 2.5, 95% CI: 1.02 to 6.17; P = 0.044). No statistically significant increased risk of death or amputation was found in white, African American, male, or female patients. Government insurance was also not associated with an increased risk for amputation (Table 1). Conclusion: Charcot Neuroarthropathy is associated with high rates of morbidity and mortality. In our cohort, there was an increased risk of mortality in patients with government funded insurance and patients over the age of 65. Further investigation exploring the role of sociodemographic factors is warranted.

Clinical characteristics and risk factors of lower extremity amputation in patients with diabetic foot.

To investigate the risk factors of lower limb amputation, and help physicians better understand the clinical characteristics of patients with diabetic foot, and make treatment strategies for these patients correctly. In this study, the inpatients with diabetic foot treated in our hospital form January 2013 to February 2021 were reviewed retrospectively. The patients were divided into amputation and conservative treatment groups. The variables of the patients, consisting of age, gender, smoking history, alcohol use, diabetes and ulcer duration, ulcer size, Wagner classification, ankle brachial index, previous amputation history, laboratory data, and medical comorbidities including hypertension, coronary artery disease, peripheral arterial disease, chronic renal insufficiency, retinopathy, and sequelae of cerebral infarction were selected for analysis to determine the risk factors of lower limb amputation. In this study, a total of 856 patients with diabetic foot were enrolled, in which 487 patients received amputation surgeries, and the amputation rate was 56.9%. There were significant differences between the two groups in gender (p=0.014), smoking history (p=0.011), ulcer duration (p=0.023), ulcer size (p=0.000), Wagner classification (p=0.000), ABI (p=0.031), peripheral arterial disease (p=0.000), HDL-C (p=0.013), osteomyelitis (p=0.000), and fibrinogen (p=0.001). A stepwise multiple logistic regression analysis revealed that male gender (p=0.003), larger ulcer size (p=0.001), higher Wagner classification grades (p=0.002), higher rate of peripheral arterial disease (p=0.02) and osteomyelitis (p=0.0001), and increased fibrinogen level (p=0.004) were independent risk factors of lower limb amputation in patients with diabetic foot. The diabetic foot patients with male sex, larger ulcer size, higher grade of Wagner classification, peripheral arterial disease or higher fibrinogen level may face higher risk of lower limb amputation.

Admission monocyte to high density lipoprotein cholesterol ratio predicts amputation in patients undergoing embolectomy for acute lower extremity ischemia.

Acute limb ischemia is a common clinical manifestation of embolism or thrombosis, which can lead to amputation. Increasing evidence suggests that various biomarkers can predict amputation at the time of admission. Identifying an easily obtainable and inexpensive indicator has always been a major objective. The aim of this study was to determine the predictive value of the admission monocyte count to the HDL-C ratio for a lower extremity amputation in patients undergoing embolectomy for acute limb ischemia. This retrospective, single-center study included 269 patients who underwent an emergent embolectomy. The study population was divided into two groups according to early amputation: the non-amputation group (n = 220) and the amputation group (n = 49). Two groups were compared based on various data. According to the multivariate regression analysis, patients with a higher CRP and MHR have a significantly higher amputation rate (HR: 1.148; CI: 1.075-1.225; p < 0.001 and HR: 1.547; CI: 1.003-2.387; p = 0.04, respectively). Patients with arterial back bleeding have a significantly lower amputation rate (HR: 0.106; CI: 0.02-0.558; p = 0.008). Our study demonstrated that preoperative CRP, MHR, and no arterial back bleeding after surgery were found to be independent predictors of amputation as a poor prognostic factor within 30 days after an embolectomy.

IDF21-0287 Validation of a Simple Scoring System predicting Amputation in Patients with Diabetic Foot

Background: Diabetic foot disease (DFD) is one of the most serious complications of diabetes with high mortality and reduction in quality of life. Diabetics are 10-30 times more prone to have lower limb amputation compared to non-diabetics and nearly 70% amputation occur in diabetics. Lower extremity amputation (LEA) is always preceded by poorly healing foot ulceration in 85% cases. There is wide variability in prevalence of lower extremity amputation in patients with diabetic foot ulcer (DFU) ranging from 0.86% in USA to 12-48% in Pakistan. Many risk factors predicting amputation has been cited in literature but several inconsistencies in results between these studies has been observed. If the risk factors are assessed, scored and then aggregated to a final sum so that a large overall score correlates with higher risk of amputation. Method: 2.1. Study Area and Period. This study was conducted in Liaquat Medical University Hospital from 06-08-2017 to 07 – 09-2019. 2.2. Study Design. Cross-Sectional Descriptive. 2.3. Inclusion Criteria: This study included 113 consecutive patients > 18 years of age of either sex with DFU attending outpatient department or admitted through emergency department. 2.4. Exclusion Criteria: Foot with peripheral artery disease not associated with diabetes mellitus, traumatic foot ulcers, patients with psychiatric illness, gestational diabetes. Results: Among 114 diabetic patients 90 (78.9 %) were male and 24 (21.1%) female. Sensory neuropathy of varying degrees was present in 107 (93.8%) patients. Amputation was performed in 36 (31.6%) whereas 78 (68.4%) patients improved. A strong relationship was found between rate of amputation with score system as higher rate of amputation was found in patients with score > 16. The other factors, age duration of diabetes and HBA1c, depth of ulcer, ABI and infection whereas poor relation with sex. Discussion: According to abhijet et.al 68.1% had sensory neuropathy who had amputation. Uysal S, et al in prospective study comprising 379 patients with DFU observed amputation in 126 (33.2%) cases. Alder Al et al in their review consisting of 14 studies comprising 94640 patients found a strong association between hyperglycemia and for each one percentage increment in HBA1c risk of amputation increases by 1.3 times. Oyibo et al in their study observed a significant correlation between Wagner grade and risk of amputation. Armstrong et al observed a 11 fold increment in major amputation in Wagner grade 3 to 5 compared to grade 1 and 2.

Comparison of Rates of Lower Extremity Amputation in Patients With and Without Gout in the US Department of Veterans Affairs Health System

Cardiometabolic and other risk factors could render patients with gout more likely to undergo lower extremity amputation (LEA). To examine the rate of and factors associated with LEA in patients with gout. In this matched cohort study using national administrative data, multivariable Cox proportional hazards regression models were used to examine the associations of gout with LEA. In analyses limited to patients with gout, attributes of serum urate control and treatment with urate-lowering therapy were examined as factors associated with LEA. This study included patients who used US Department of Veterans Affairs services from January 1, 2000, to July 31, 2015. Patients with gout were identified using diagnostic codes and matched with up to 10 controls by age, sex, and year of benefit enrollment. Data analysis was performed from January 26, 2021, to September 3, 2021. Gout classification served as the primary independent variable of interest. In analyses limited to patients with gout, factors associated with serum urate control and urate-lowering therapy were examined. Overall LEA, as well as toe, transmetatarsal, below-the-knee, and above-the-knee amputation. This cohort study included 5 924 918 patients, 556 521 with gout (mean [SD] age, 67 [12] years; 550 963 (99.0%) male; 88 853 [16.0%] Black non-Hispanic; 16 981 [4.3%] Hispanic/Latinx; 345 818 [62.1%] White non-Hispanic; 80 929 [14.5%] with race and ethnicity data missing; and 23 940 [4.3%] classified as other) and 5 368 397 without gout (mean [SD] age, 67 [12] years; 5 314 344 [99.0%] male; 558 464 [10.4%] Black non-Hispanic; 204 291 [3.0%] Hispanic/Latinx; 3 188 504 [59.4%] White non-Hispanic; 1 257 739 [23.4%)] with race and ethnicity data missing; and 159 399 [3.0%] classified as other). Compared with patients without gout, patients with gout were more likely to undergo amputation, an increased rate that remained after adjustment (adjusted hazard ratio, 1.20; 95% CI, 1.16-1.24) and was highest for below-the-knee amputation (adjusted hazard ratio, 1.59; 95% CI, 1.39-1.81). In those with gout, poor serum urate control (mean >7 mg/dL during the preceding year) was associated with a 25% to 37% increase in the rate of amputation. In contrast, treatment with urate-lowering therapy was not associated with the LEA rate. In this matched cohort study, patients with gout were more likely to undergo LEA. This increase was independent of other comorbidities that have been associated with amputation, including diabetes and peripheral vascular disease. Serum urate control was independently associated with the LEA rate, suggesting the possibility that lower extremity amputation may be preventable in some patients.

Association Among Current Cigarette Smoking, Heavy Alcohol Consumption, Regular Exercise, and Risk of Lower Extremity Amputation in Patients with Diabetic Foot: A Nationwide Population-Based Study

Association Among Current Cigarette Smoking, Heavy Alcohol Consumption, Regular Exercise, and Risk of Lower Extremity Amputation in Patients with Diabetic Foot: A Nationwide Population-Based Study

Risk of lower extremity amputations in patients with type 2 diabetes using sodium-glucose co-transporter 2 inhibitors

AimsTo compare the influence of sodium-glucose co-transporter 2 inhibitors (SGLT2i) and dipeptidyl peptidase-4 inhibitors (DPP-4i) on the risk of lower extremity amputations in patients with type 2 diabetes in Slovenia.MethodsThis retrospective cohort study included patients aged 40 years or more who were administered a newly introduced SGLT2i or DPP-4i between June 2014 and June 2018. Patients treated with insulin at baseline and patients with a history of amputation were excluded. Patients were matched in a 1:1 ratio using propensity score matching. Survival analysis was performed; hazard ratio (HR) and ratios of cumulative hazards at 1, 2, 3, and 4 years were estimated. On-treatment and intention-to-treat approaches were used.ResultsThe study cohort (mean age: 64 years) consisted of 2,939 new users of SGLT2i (empagliflozin, 59%; dapagliflozin, 41%) matched to 2,939 new users of DPP-4i. In the on-treatment analysis (median follow-up of 2 years), the incidence of amputations was higher in SGLT2i than in DPP-4i users (4.2 vs. 2.7 per 1,000 patient years), resulting in a HR of 1.58 (95% CI 0.85–2.92; p = 0.145). An intention-to-treat analysis yielded to similar HR of 1.86 (95% CI: 1.10–3.14; p = 0.020). There was no difference in amputation rates in the first two years, but SGLT2i users had a 2.81-fold higher (95% CI: 1.63–4.84; p = 0.007) cumulative hazard of amputation at 4 years than did DPP-4i users.ConclusionsCompared with DPP-4i use, SGLT2i use did not result in a statistically significant higher overall risk of lower extremity amputations. However, the results suggest that SGLT2i may increase the risk of amputation with long-term use.

Geographic and Socioeconomic Disparities in Major Lower Extremity Amputation Rates in Metropolitan Areas.

BackgroundRates of major lower extremity amputation in patients with peripheral artery disease are higher in rural communities with markers of low socioeconomic status, but most Americans live in metropolitan areas. Whether amputation rates vary within US metropolitan areas is unclear, as are characteristics of high amputation rate urban communities.Methods and ResultsWe estimated rates of major lower extremity amputation per 100 000 Medicare beneficiaries between 2010 and 2018 at the ZIP code level among ZIP codes with ≥100 beneficiaries. We described demographic characteristics of high and low amputation ZIP codes, and the association between major amputation rate and 3 ZIP code–level markers of socioeconomic status—the proportion of patients with dual eligibility for Medicaid, median household income, and Distressed Communities Index score—for metropolitan, micropolitan, and rural ZIP code cohorts. Between 2010 and 2018, 188 995 Medicare fee‐for‐service patients living in 31 391 ZIP codes with ≥100 beneficiaries had a major lower extremity amputation. The median (interquartile range) ZIP code–level number of amputations per 100 000 beneficiaries was 262 (75–469). Though nonmetropolitan ZIP codes had higher rates of major amputation than metropolitan areas, 78.2% of patients undergoing major amputation lived in metropolitan areas. Compared with ZIP codes with lower amputation rates, top quartile amputation rate ZIP codes had a greater proportion of Black residents (4.4% versus 17.5%, P<0.001). In metropolitan areas, after adjusting for clinical comorbidities and demographics, every $10 000 lower median household income was associated with a 4.4% (95% CI, 3.9–4.8) higher amputation rate, and a 10‐point higher Distressed Communities Index score was associated with a 3.8% (95% CI, 3.4%–4.2%) higher amputation rate; there was no association between the proportion of patients eligible for Medicaid and amputation rate. These findings were comparable to the associations identified across all ZIP codes.ConclusionsIn metropolitan areas, where most individuals undergoing lower extremity amputation live, markers of lower socioeconomic status and Black race were associated with higher rates of major lower extremity amputation. Development of community‐based tools for peripheral artery disease diagnosis and management targeted to communities with high amputation rates in urban areas may help reduce inequities in peripheral artery disease outcomes.