Outcomes following Lower Extremity Amputation in Patients with Diabetes Mellitus and Peripheral Arterial Disease

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 and rates of revision amputation following ischemic lower major limb amputations: A 10-year retrospective analysis

OBJECTIVES

This study aimed to evaluate the rates and risk factors associated with revision amputation following ischemic lower major limb amputations, focusing on cases related to peripheral arterial disease.

PATIENTS AND METHODS

This retrospective study included 253 patients (174 males, 79 females; mean age: 73.1±12.2 years; range, 44 to 99 years) who underwent ischemic foot amputation between December 2012 and December 2022. Eligible patients were over 18 years old and had major lower extremity amputations due to peripheral arterial disease or chronic arterial occlusion. Exclusions were made for amputations due to diabetic foot conditions, trauma, tumors, or osteomyelitis and minor lower extremity amputations.

RESULTS

Above-knee amputations were the most common type of amputation, accounting for 56.5% (n=143) of cases. Revision amputations occurred in 27.3% (n=69) of patients, with significantly higher rates in those with open wounds at first admission (chi-square [χ2 ]=9.81, p=0.002). Patients with occlusion at the popliteal artery level had a higher rate of revision amputation following below-knee amputation (p=0.034). Each additional year of age decreased the likelihood of revision amputation by 2.3% (p=0.049). Vacuum-assisted closure therapy was associated with higher revision rates (χ2 =22.71, p<0.001). Patients who developed infections (n=40) had a significantly higher rate of revision amputations (n=26, p<0.001). Elevated preoperative C-reactive protein levels were also correlated with an increased risk of revision (p=0.006).

CONCLUSION

Patients with ischemic lower limb amputations, particularly those presenting with open wounds, are at higher risk for revision amputation. Elevated preoperative C-reactive protein levels, infections, age, and the initial level of amputation significantly impact the likelihood of reamputation.

Association between fibrinogen level and length of stay in patients with lower extremity atherosclerotic disease: a retrospective cohort study

The level of fibrinogen in patients with lower extremity atherosclerosis (LEAD) has been widely identified as a risk factor contributing to adverse outcomes. However, some knowledge gaps remain regarding fibrinogen levels and downstream adverse outcomes, such as length of stay (LOS). We conducted this study to examine the association between fibrinogen level and LOS in LEAD patients. The retrospective cohort study included 1428 LEAD patients between January 2014 and November 2021 in China. Several generalized linear models with a negative binomial link function were used to evaluate the association between fibrinogen level and LOS. The area under the curve (AUC) was used to evaluate the predicting effect of fibrinogen level on a LOS greater than 10 days (median LOS). The median age of the patients was 70 years old, and 1153 (80.74%) were males. Fibrinogen level was positively associated with LOS (β = 1.14; 95% CI, 0.42-1.86; p = 0.002) in LEAD patients after controlling for age, gender, number of historical hospitalizations, surgical history, vascular disease history, drinking history, smoking history, insurance type, surgical approach, lesion site, weight loss, Fontaine classification, age-adjusted Charlson comorbidity index, urea, total protein, activated partial thromboplastin time, thrombin time, prothrombin time-international normalized ratio, calcium, triglyceride, albumin/globulin ratio, phosphorus, and D-dimer. The fibrinogen-added prediction model demonstrated good discrimination and calibration, with an AUC value of 0.807. Fibrinogen level was positively associated with LOS in LEAD patients. The fibrinogen level is a widely available and easy-to-measure biochemical indicator, and it could be used as a suitable indicator for the prognosis and prophylaxis of prolonged LOS in patients with LEAD during hospitalization.

Impact of N-Acetyl-Cysteine on Ischemic Stumps Following Major Lower Extremity Amputation: A Pilot Randomized Clinical Trial

OBJECTIVE

To evaluate the impact of N-acetyl-cysteine (NAC) on amputation stump perfusion and healing in patients with critical limb-threatening ischemia (CLTI).

BACKGROUND

Patients with CLTI are at increased risk of poor amputation site healing leading to increased procedure-associated morbidity.

METHODS

In a pilot, double-blind, placebo-controlled, randomized controlled trial, patients with CLTI undergoing major elective lower extremity amputation were randomized 1:1 to intravenous NAC (1200 mg twice-daily) or placebo for up to 5 days postoperatively. Primary outcomes were change in stump perfusion at postoperative day 3 (POD3) and POD5, and healing at POD30. Stumps were serially evaluated for wound healing, and tissue perfusion was evaluated using noninvasive laser-assisted fluorescent angiography.

RESULTS

Thirty-three patients were randomized to NAC (n = 16) or placebo (n = 17). Thirty-one patients were eligible for intent-to-treat analysis (NAC14; placebo17). Twenty patients (NAC7; placebo13) had amputation stump perfusion defects at POD0 and were considered high-risk for poor healing. Intent-to-treat analysis revealed no significant differences between treatment groups. Subgroup analysis of high-risk patients revealed differences in stump perfusion defect size (NAC-0.53-fold, placebo +0.71-fold; 95% confidence interval -2.11 to-0.35; P < 0.05) and healing (NAC [100%], placebo [46%]; P < 0.01) between study treatments.

CONCLUSIONS

Postoperative NAC administration may improve amputation stump perfusion and healing in patients with CLTI and tissue perfusion defects at the time of amputation. Intraoperative laser-assisted fluorescent angiogra-phy may help surgeons identify high-risk patients with stump perfusion defects and provide early adjunctive interventions. Future studies can further explore the therapeutic benefits of NAC in the healing and perfusion of other surgical operative sites in high-risk individuals.

TRIAL REGISTRATION

clinicaltrials.gov, Identifier: NCT03253328.

Modernizing Diabetes Care Quality Measures

The proliferation of diabetes quality measures in the US since the mid-1990s has increased the burden of measurement without commensurate improvements in the quality of care or health outcomes. Measures in use today do not represent or incentivize achievement of care goals in all domains of quality that are necessary to achieve optimal diabetes health. We recommend reimagining and improving diabetes quality measurement through the following propositions: widespread adoption of new measures and modernization of existing measures across six domains of quality; use of a subset of new and modernized metrics as top-line measures for reporting and reimbursement; and optional use of the remaining new and modernized measures for evaluative purposes at all levels of the care delivery system to identify and address gaps in care quality and outcomes. These propositions would support practices and policies at all levels of the health care system to improve the health of people with diabetes.

Association of Advanced Glycation End Products With Lower-Extremity Atherosclerotic Disease in Type 2 Diabetes Mellitus

Aims: Advanced glycation end products (AGEs) were reported to be correlated with the development of diabetes, as well as diabetic vascular complications. Therefore, this study aimed at investigating the association between AGEs and lower-extremity atherosclerotic disease (LEAD). Methods: A total of 1,013 type 2 diabetes patients were enrolled. LEAD was measured through color Doppler ultrasonography. The non-invasive skin autofluorescence method was performed for AGEs measurement. Considering that age plays an important role in both AGEs and LEAD, age-combined AGEs, i.e., AGE_age index (define as AGEs × age/100) was used for related analysis. Results: The overall prevalence of LEAD was 48.9% (495/1,013). Patients with LEAD showed a significantly higher AGE_age (p < 0.001), and the prevalence of LEAD increased with ascending AGE_age levels (p for trend < 0.001). Logistic regression analysis revealed that AGE_age was significantly positively associated with risk of LEAD, and the odds ratios of presence of LEAD across quartiles of AGE_age were 1.00, 1.72 [95% confidence interval (CI) = 1.14-2.61], 2.72 (95% CI = 1.76-4.22), 4.29 (95% CI = 2.69-6.85) for multivariable-adjusted model (both p for trend < 0.001), respectively. The results were similar among patients of different sexes, body mass index, and with or without diabetes family history. Further, AGE_age presented a better predictive value for LEAD than glycated hemoglobin A_1c (HbA_1c), with its sensitivity, specificity, and area under the curve of 75.5% (95% CI = 71.6-79.2%), 59.3% (95% CI = 54.9-63.6%), and 0.731 (0.703-0.758), respectively. Conclusion: AGE_age, the non-invasive measured skin AGEs combined with age, seems to be a more promising approach than HbA_1c in identifying patient at high risk of LEAD.

Serum Legumain Is Associated with Peripheral Artery Disease in Patients with Type 2 Diabetes

BACKGROUND

Legumain is related to carotid atherosclerotic plaques and may be a new biomarker of carotid atherosclerosis. However, the association between legumain and peripheral artery disease (PAD) of lower extremity has been less studied. This study is aimed at exploring the potential link between legumain and PAD in patients with type 2 diabetes mellitus (T2DM).

METHODS

A cross-sectional study was conducted on 483 hospitalized T2DM patients. The serum legumain level was measured by a sandwich enzyme-linked immunosorbent assay. PAD was evaluated by color Doppler sonography. The association between legumain and PAD was tested by logistic regression. The predictive power of legumain for PAD was evaluated with the receiver-operating-characteristic (ROC) curve.

RESULTS

Overall, 201 (41.6%) patients suffered from PAD. Patients with PAD had significantly higher serum legumain level than those without PAD [11.9 (6.3, 17.9) μg/L vs. 7.6 (3.2, 14.2) μg/L, p < 0.001]. Logistic regression showed that a higher serum legumain level was independently associated with a greater risk of PAD in T2DM patients [adjusted odds ratio (aOR): 1.03; 95% confidence interval (CI): 1.01-1.06]. The area under the ROC curve was 0.634 (95% CI, 0.585 to 0.684).

CONCLUSION

High serum legumain level was significantly correlated with an increased risk of PAD in T2DM patients.

Visit-to-visit variability of glycated albumin was associated with incidence or progression of lower extremity atherosclerotic disease

BACKGROUND

The aim of this study was to investigate the association of visit-to-visit variability of hemoglobin A1c (HbA1c) and glycated albumin (GA) with the risk of lower extremity atherosclerotic disease (LEAD).

METHOD

We performed a prospective cohort study of 436 patients with type 2 diabetes (258 men and 178 women) with at least 3 measurements of HbA1c and GA prior to baseline investigation from the Department of Endocrinology and Metabolism, Shanghai Sixth People's Hospital. Different HbA1c and GA variability markers were calculated. Multivariable Cox proportional hazard regression models were used to demonstrate the association between visit-to-visit HbA1c and GA variability and the risk of incident or progressive LEAD.

RESULTS

During a mean follow-up period of 3.77 years, 112 participants developed LEAD. Multivariate-adjusted hazard ratios (HRs) of LEAD across tertiles of GA-CV values were 1.00, 1.06 (95% confidence interval [CI] 0.65-1.75), and 1.71 (95% CI 1.07-2.73) (P for trend = 0.042), respectively. When we used GA-VIM and GA-ARV values as exposures, similar positive associations with the risk of LEAD primary were found. Multivariate-adjusted HRs of LEAD for each 1 unit increase in GA-CV, GA-VIM and GA-ARV were 1.03 (95% CI 1.01-1.06), 1.32 (95% CI 1.03-1.69), and 1.07 (95%CI 1.01-1.15), respectively. However, there was no significant association between visit-to-visit variability of HbA1c and the risk of LEAD.

CONCLUSIONS

Visit-to-visit variability of GA may be an optimal biomarker in relation to LEAD risk among patients with type 2 diabetes.

The association between serum growth differentiation factor 15 levels and lower extremity atherosclerotic disease is independent of body mass index in type 2 diabetes

BACKGROUND

Clinical and basic investigations have indicated a significant association between circulating growth differentiation factor 15 (GDF15) and cardiovascular disease; however, the relationship between GDF15 and lower extremity atherosclerotic disease (LEAD) has been less studied. The present study aimed to explore the association between GDF15 and LEAD in Chinese patients with type 2 diabetes mellitus (T2DM). Considering that obesity is an important factor associated with circulating GDF15 levels, whether the relationship between serum GDF15 levels and LEAD is affected by body mass index (BMI) was also analysed.

METHODS

A total of 376 hospitalized T2DM patients were enrolled (161 with LEAD and 215 without LEAD). A sandwich enzyme-linked immunosorbent assay was used to detect the serum GDF15 levels. The femoral intima-media thickness (F-IMT) and LEAD were assessed by ultrasonography.

RESULTS

Patients with LEAD had significantly higher serum GDF15 levels than those without LEAD, regardless of whether their BMI was < 25 kg/m² or ≥ 25 kg/m² (both P < 0.05). Serum GDF15 levels were independently positively related to the F-IMT (standardized β = 0.162, P = 0.002). After adjusting for confounding factors, per 1-standard deviation (SD) increase in the serum GDF15 levels was significantly related to an approximately 1.4-fold increased risk of LEAD in the total population (P < 0.05). Regardless of whether the BMI was < 25 kg/m² or ≥ 25 kg/m², this association remained significant, with approximately 1.6- and 1.4-fold increased risks of LEAD, respectively (both P < 0.05).

CONCLUSIONS

High serum GDF15 levels were significantly correlated with an increased risk of LEAD in T2DM patients, and this relationship was independent of BMI.