High levels of plasma malondialdehyde, protein carbonyl, and fibrinogen have prognostic potential to predict poor outcomes in patients with diabetic foot wounds: a preliminary communication

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.

Oxidative Stress and Inflammatory Biomarkers in Patients with Diabetic Foot

Background and Objectives: Diabetic foot (DF) development is driven by complex interactions of hyperglycemia, inflammation, and oxidative stress (OS). We aimed to investigate OS and inflammatory biomarkers in patients with DF and their potential to improve early diagnosis and management of DF. Materials and Methods: The prooxidant−antioxidant balance (PAB), superoxide dismutase (SOD), total oxidative status (TOS), total sulfhydryl groups (SHG), routine biochemical parameters, and complete blood count were determined in 42 patients with type-2 DM, of which 23 patients had DF, while 19 patients were without DF complications. The neutrophils-to-lymphocyte ratio (NLR) was evaluated as a biomarker of inflammation. Results: Patients with DF had significantly higher (p < 0.05) PAB levels (170 ± 33.9 U/L) compared to those without DF complications (142 ± 31.3 U/L). In addition, patients with DF had significantly reduced SOD activities (p < 0.01). NLR values were significantly higher in the DF group (median: 2.8; interquartile range: 2.0−4.3) than in the group without DF (median: 1.4; interquartile range: 1.4−2.1; p < 0.01). A positive correlation was found between the PAB and NLR index (r = 0.449; p < 0.05). The diagnostic accuracy of both PAB (AUC = 0.741; p < 0.01) and NLR (AUC = 0.760; p < 0.01) was estimated as acceptable. Conclusions: In conclusion, the development of DF is associated with enhanced OS and inflammation processes. PAB and NLR could be useful non-invasive biomarkers of DF development.

The role of extracellular matrix in the pathophysiology of diabetic wounds

Impaired healing leading to the formation of ulcerated wounds is a critical concern in patients with diabetes. Abnormalities in extracellular matrix (ECM) production and remodeling contribute to tissue dysfunction and delayed healing. Specifically, diabetes-induced changes in the expression and/or activity of structural proteins, ECM-modifying enzymes, proteoglycans, and matricellular proteins have been reported. In this review, we provide a summary of the key ECM molecules and associated changes in skin and diabetic wounds. Such information should allow for new insights in the understanding of impaired wound healing and lead to the development of ECM-based therapeutic strategies.

The correlation between blood oxidative stress and sialic acid content in diabetic patients with nephropathy, hypertension, and hyperlipidemia

This clinical study was designed to find out the correlation between oxidative stress and sialic acid (SA) content of plasma and RBCs in patients with type 2 diabetes. We evaluated SA concentration and oxidative stress biomarkers in healthy subjects and diabetic patients with and without complications in a cross-sectional survey. Significant changes in oxidative stress biomarkers and RBC-SA were revealed in the diabetic patients compared to those in the healthy group. Plasma SA significantly increased with an increase in lipid peroxidation of RBCs (LPO-RBC) (P < 0.001) in the diabetic patients without complication. RBC-SA significantly decreased with an elevation in LPO-RBC (P < 0.001) in all the diabetic patients and those with nephropathy. There was no significant correlation between plasma and RBC-SA and other oxidative stress biomarkers in the diabetic subjects. In multiple logistic regression analysis, RBC-SA was independently related to LPO-RBC in all the diabetic patients and those with nephropathy. We conclude that the induction of LPO-RBC in diabetic patients and those with nephropathy may influence the SA decomposition of RBC membrane, thereby altering its functions and transporter activities. Therefore, LPO-RBC and SA levels in RBCs can be used for prediction of diabetic nephropathy, and further studies to evaluate other factors contributing to desialylation of RBC membrane are justified.

The Role of Serum Procalcitonin, Interleukin-6, and Fibrinogen Levels in Differential Diagnosis of Diabetic Foot Ulcer Infection

AIMS

We aimed to evaluate the roles of interleukin-6 (IL-6), PCT, and fibrinogen levels in the differential diagnosis of the patients with infected diabetic foot ulcer (IDFU) and noninfected diabetic foot ulcer (NIDFU) and to compare those with C-reactive protein (CRP), white blood cell (WBC), and erythrocyte sedimentation rate (ESR).

METHODS

Patients over 18 years with a diagnosis of type 2 diabetes mellitus and DFU who were followed up in our hospital between 1 January 2016 and 1 January 2017 were included in the study. In addition to this patient group, patients with diabetes but without DFU were determined as the control group.

RESULTS

Thirty-eight patients with IDFU, 38 patients with NIDFU, and 43 patients as the control group were included in the study. Fifty-six point three percent of the patients who participated in the study were males, and the mean age was 61.07 ± 11.04 years. WBC, ESR, CRP, IL-6, and fibrinogen levels of the cases with IDFU were determined to be significantly higher compared to the cases in NIDFU (p < 0.01). The area under the ROC curve (AUROC) value was highest for CRP (0.998; p < 0.001), and the best cut-off value for CRP was 28 m/L. The best cut-off values for fibrinogen, IL-6, ESR, and WBC were 480 mg/dL, 105.8 pg/mL, 31 mm/h, and 11.6 (103 μ/L), respectively.

CONCLUSION

Serum PCT levels were not found to be effective in the discrimination of IDFU and NIDFU. Serum IL-6 and fibrinogen levels seem to be two promising inflammatory markers in the discrimination of IDFU.

Healing enhancement of diabetic wounds by locally infiltrated epidermal growth factor is associated with systemic oxidative stress reduction

The diabetic foot ulcer (DFU) is the leading cause of lower extremity amputation worldwide and is directly associated with comorbidity, disability and mortality. Oxidative stress mechanisms have been implicated in the pathogenesis of these wounds. Intra-lesional infiltration of epidermal growth factor has emerged as a potential therapeutic alternative to allow for physiological benefit while avoiding the proteolytic environment at the centre of the wound. The aim of this study was to characterise the response of patients with DFUs to epidermal growth factor treatment in terms of redox status markers. Experimental groups included patients with DFUs before and 3-4 weeks after starting treatment with epidermal growth factor; compensated and non-compensated diabetic patients without ulcers; and age-matched non-diabetic subjects. Evaluations comprised serum levels of oxidative stress and antioxidant reserve markers. Patients with DFUs exhibited the most disheveled biochemical profile, with elevated oxidative stress and low antioxidant reserves, with respect to non-ulcerated diabetic patients and to non-diabetic subjects. Epidermal growth factor intra-lesional administration was associated with a significant recovery of oxidative stress and antioxidant reserve markers. Altogether, our results indicate that epidermal growth factor intra-ulcer therapy contributes to restore systemic redox balance in patients with DFUs.

Fibrinogen: A Marker in Predicting Diabetic Foot Ulcer Severity

Aims. To examine whether fibrinogen levels are a valuable biomarker for assessing disease severity and monitoring disease progression in patients with diabetic foot ulcer (DFU). Methods. A retrospective study was designed to examine the utility of fibrinogen in estimating disease severity in patients with DFU admitted to our hospital between January 2015 and January 2016. In total, 152 patients with DFU were enrolled in the study group, and 52 age and gender matched people with diabetes but no DFU were included as the control group. DFU severity was assessed using Wagner criteria. Results. Patients with DFU were divided into 2 subgroups based on the Wagner criteria. Mean fibrinogen values were significantly higher in patients with DFU grade ≧ 3 compared to those with DFU grades 1-2 (5.23 ± 1.37 g/L versus 3.61 ± 1.04 g/L). Using ROC statistic, a cut-off value of 5.13 g/L indicated the possible amputation with a sensitivity of 81.8% and a specificity of 78.9% (positive predictive value [PPV] 78.6%, negative predictive value [89.0%]). Fibrinogen values were found to be correlated with CRP levels, neutrophil, and WBC count. Conclusions. Fibrinogen levels might be a valuable tool for assessing the disease severity and monitoring the disease progression in patients with DFU.

Role of nitrosative and oxidative stress in neuropathy in patients with type 2 diabetes mellitus

OBJECTIVES

Evidences of oxidative and/or nitrosative stress in type 2 diabetes mellitus were demonstrated in experimental and human studies. This study is aimed to assess the serum peroxynitrite and oxidized lipoproteins in patients with type 2 diabetes mellitus presented with clinical and laboratory evidences of peripheral neuropathy.

MATERIALS AND METHODS

Eighty four patients with type 2 diabetes mellitus (51 of them had neuropathy) and 31 apparent healthy subjects were studied in the unit of neurophysiology at the University Hospital of Medical College, Al-Nahrin University in Baghdad, Iraq. Neuropathy total symptom score (NTSS), neuropathy impairment score in the lower leg (NIS-LL), and nerve conduction velocity of sensory (ulnar and sural) and motor (ulnar and common peroneal) nerves were used to assess the neuropathy. Fasting venous blood was obtained from each participant for the determination of serum glucose and oxidized lipoproteins.

RESULTS

The electrophysiology study revealed significant decrease in conduction velocity of ulnar (sensory and motor components), sural, and common peroneal nerves in diabetic neuropathy compared to diabetics without neuropathy and healthy subjects. Significant high level of serum peroxynitrite was found in diabetic patients with or without neuropathy compared with non-diabetics. The changes in serum-oxidized lipoproteins in patients with diabetics with or without neuropathy were non-significantly differed from healthy subjects. Neither nitrosative stress nor oxidative stress indices correlated with the variables that are related to the neuropathy.

CONCLUSION

It concludes that evidence of nitrosative and to less extent the oxidative stress is associated with neuropathy in type 2 diabetes mellitus and their indices not correlated with variables related to neuropathy.

Cellular dysfunction in diabetes as maladaptive response to mitochondrial oxidative stress

Oxidative stress has been implicated in diabetes long-term complications. In this paper, we summarize the growing evidence suggesting that hyperglycemia-induced overproduction of superoxide by mitochondrial electron transport chain triggers a maladaptive response by affecting several metabolic and signaling pathways involved in the pathophysiology of cellular dysfunction and diabetic complications. In particular, it is our goal to describe physiological mechanisms underlying the mitochondrial free radical production and regulation to explain the oxidative stress derived from a high intracellular glucose concentration and the resulting maladaptive response that leads to a cellular dysfunction and pathological state. Finally, we outline potential therapies for diabetes focused to the prevention of mitochondrial oxidative damage.

An inter-laboratory validation of methods of lipid peroxidation measurement in UVA-treated human plasma samples

Lipid peroxidation products like malondialdehyde, 4-hydroxynonenal and F(2)-isoprostanes are widely used as markers of oxidative stress in vitro and in vivo. This study reports the results of a multi-laboratory validation study by COST Action B35 to assess inter-laboratory and intra-laboratory variation in the measurement of lipid peroxidation. Human plasma samples were exposed to UVA irradiation at different doses (0, 15 J, 20 J), encoded and shipped to 15 laboratories, where analyses of malondialdehyde, 4-hydroxynonenal and isoprostanes were conducted. The results demonstrate a low within-day-variation and a good correlation of results observed on two different days. However, high coefficients of variation were observed between the laboratories. Malondialdehyde determined by HPLC was found to be the most sensitive and reproducible lipid peroxidation product in plasma upon UVA treatment. It is concluded that measurement of malondialdehyde by HPLC has good analytical validity for inter-laboratory studies on lipid peroxidation in human EDTA-plasma samples, although it is acknowledged that this may not translate to biological validity.

Immune mediators in patients with acute diabetic foot syndrome

OBJECTIVE Subclinical inflammation is an important risk factor for type 2 diabetes and diabetes complications. However, data on the association between inflammation and acute diabetic foot syndrome are scarce. The aim of this study was to compare systemic immune mediators in diabetic patients with and without an ulcer and to identify modulating factors. RESEARCH DESIGN AND METHODS Circulating levels of acute-phase proteins, cytokines, and chemokines were measured in diabetic patients with an ulcer (n = 170) and without an ulcer (n = 140). Of the patients, 88% had type 2 diabetes. RESULTS Patients with an acute foot ulcer had higher levels of C-reactive protein (CRP), fibrinogen, interleukin (IL)-6, macrophage migration inhibitory factor, macrophage inflammatory protein-1alpha, and interferon-gamma-inducible protein-10 as well as lower levels of RANTES (regulated on activation normal T-cell expressed and secreted) (all P < 0.01). No differences were found for IL-8, IL-18, and monocyte chemoattractant protein-1. Most of these associations persisted after adjustment for demographic and anthropometric data, metabolic confounders, and diabetes complications. In multivariate models, size of ulcer according to the University of Texas classification but not the grade of infection was independently associated with three markers of subclinical inflammation (CRP, IL-6, and fibrinogen). CONCLUSIONS We demonstrate in our cross-sectional study that acute foot ulcers and their severity are associated with a marked upregulation of acute-phase proteins, cytokines, and chemokines independently of the concomitant infection. Further studies should investigate whether an activation of the immune system precedes the development of foot ulcer and whether anti-inflammatory therapies might be effective.