Obesity and Dyslipidemia Synergistically Exacerbate Psoriatic Skin Inflammation

Epidemiology of lipid disturbances in psoriasis: An analysis of trends from 2006 to 2023

INTRODUCTION

A strong link has been established between psoriasis and lipid disturbances; however, no study has systematically examined their global epidemiology.

METHODS

We searched six databases from their inception up to October 1, 2023. Data analysis was conducted using Stata SE 15.1. We performed subgroup, meta-regression, and sensitivity analyses to assess the heterogeneity of the pooled studies.

RESULTS

Our review included 239 studies comprising 15,519,570 participants. The pooled prevalence rate of dyslipidemia among individuals with psoriasis was 38 %.

CONCLUSION

Patients with severe psoriasis should undergo screening for lipid abnormalities. This can facilitate the early detection of lipid dysfunction and associated cardiovascular comorbidities.

Alterations of circulating free fatty acids in patients with pemphigus vulgaris

Free fatty acids (FFA) have gained research interest owing to their functions in both local and systemic immune regulation. Changes in the serum levels of anti-inflammatory short chain fatty acids (SCFA), primarily derived from the gut microbiota, and pro-inflammatory medium (MCFA) and long (LCFA) chain fatty acids, derived from either the gut microbiota or the diet, have been associated with autoimmunity. Circulating FFA were retrospectively analysed by a gas chromatography-mass spectrometry method in the serum of 18 patients with pemphigus vulgaris (PV) at the baseline and 6 months (n = 10) after immunosuppressive treatments, and 18 healthy controls (HC). Circulating FFA were correlated with the Pemphigus Disease Area Index (PDAI) and serum concentrations of interferon-gamma (IFN-γ), Interleukin (IL)-17A, IL-5, IL-10 and IL-21. Principal Component analysis computed on FFA abundances revealed significant differences in the profile of SCFA (p = 0,012), MCFA (p = 0.00015) and LCFA (p = 0,035) between PV patients and HC, which were not significantly changed by immunosuppressive treatments. PV patients showed a significantly lower serum concentration of propionic (p < 0.0005) and butyric (p < 0.0005) acids, SCFA with anti-inflammatory functions, while hexanoic (p < 0.0005) and hexadecanoic (p = 0.0006) acids, pro-inflammatory MCFA and LCFA respectively, were over-represented. Treatments induced a significant decrease of hexanoic (p = 0.035) and a further increase of hexadecanoic (p = 0.046) acids. Positive correlations emerged between IFN-γ and acetic acid (Rho = 0.60), IFN-γ and hexanoic acid (Rho = 0.46), IL-5 and both hexadecanoic acid (Rho = 0.50) and octadecanoic acid (Rho = 0.53), butyric acid and PDAI (Rho = 0.53). PV was associated with a remarked imbalance of circulating FFA compared to HC. The serum alterations of SCFA, MCFA, and LCFA may contribute to promoting inflammation in PV. Deeper insights into the immunomodulatory functions of these molecules may pave the way for personalized dietary interventions in PV patients.

Increased Mortality Risk at Septic Condition in Inflammatory Skin Disorders and the Effect of High-Fat Diet Consumption

In recent years, attention has increasingly focused on various infectious diseases. Although some fatalities are directly attributed to the causative virus, many result from complications and reactive inflammation. Patients with comorbidities are at a higher risk of mortality. Refractory skin conditions such as atopic dermatitis, psoriasis, and epidermolysis bullosa, known for an elevated risk of sepsis, partly owe this to compromised surface barrier function. However, the detailed mechanisms underlying this phenomenon remain elusive. Conversely, although the detrimental effects of a high-fat diet on health, including the onset of metabolic syndrome, are widely recognized, the association between diet and susceptibility to sepsis has not been extensively explored. In this study, we examined the potential causes and pathogenesis of increased sepsis susceptibility in inflammatory skin diseases using a mouse dermatitis model: keratin 14-driven caspase-1 is overexpressed (KCASP1Tg) in mice on a high-fat diet. Our findings reveal that heightened mortality in the dermatitis mouse model is caused by the inflamed immune system due to the chronic inflammatory state of the local skin, and administration of LPS causes a rapid increase in inflammatory cytokine levels in the spleen. Intake of a high-fat diet exacerbates these cytokine levels. Interestingly, we also observed a reduced expression of Toll-like receptor 4 (TLR4) in monocytes from KCASP1Tg mice, potentially predisposing these animals to heightened infection risks and associated complications. Histological analysis showed a clear decrease in T and B cells in the spleen of KCASP1Tg mice fed a high-fat diet. Thickening of the alveolar wall, inflammatory cell infiltration, and alveolar hemorrhage were more prominent in the lungs of KCASP1Tg and KCASP1Tg with fat mice. We postulate that the chronic, non-infectious inflammation induces a negative feedback loop within the inflammatory cascade, and the suppressed expression of TLR4 renders the mice more susceptible to infections. Therefore, it is imperative for individuals with chronic skin inflammation to closely monitor disease progression upon infection and seek timely and appropriate treatment. Additionally, chronic inflammation of adipose tissue, induced by high-fat food intake, combined with dermatitis inflammation, may exacerbate infections, necessitating a review of dietary habits.

The Cross Talk Between Psoriasis, Obesity, and Dyslipidemia: A Meta-Analysis

Although psoriasis is a multi-organ disease, it is usually managed as a skin disease, ignoring its associated serious comorbidities. This meta-analysis aimed to investigate the relationship between psoriasis, dyslipidemia, and obesity. Two authors independently searched three databases (PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), The Cochrane Library, and Google Scholar). The search was set for articles published in the English language during the period from January 2013 to August 2023. The keywords "psoriasis", "hypercholesterolemia", "dyslipidemia", "low-density lipoproteins", "high body mass index", and "obesity", were used. Out of the 145 full texts reviewed, only seven studies fulfilled the inclusion and exclusion criteria (773,761 participants and 196,593 events). Psoriasis was associated with dyslipidemia and obesity (odds ratio (OR)=1.63, 95% CI: 1.42-1.88 and OR=1.70, 95% CI: 1.43-2.02), respectively, with significant heterogeneity (98% and 97%, respectively). Dyslipidemia and obesity were significant psoriasis comorbidities; a broader approach, viewing psoriasis as a multi-organ disease, is recommended for optimal treatment and outcomes.

A Holistic View of Psoriasis: Examining Its Association With Dyslipidemia and Obesity in a Decade-Long Systematic Review and Meta-Analysis

Psoriasis is a multifaceted inflammatory condition with systemic implications, impacting not only the skin but also various organs and overall health. It is associated with mood disorders, malignancy, infections, and components of metabolic syndrome, including diabetes, atherogenic dyslipidemia, and obesity. The coexistence of psoriasis with obesity poses additional challenges, as obesity worsens psoriasis severity and reduces treatment effectiveness. This systematic review and meta-analysis aim to further understand the associations between psoriasis, dyslipidemia, and obesity. Our systematic review of six studies revealed significant links between psoriasis and both dyslipidemia and obesity. Individuals with psoriasis exhibited a 1.40-fold higher likelihood of dyslipidemia (odds ratio (OR) 1.40, 95% confidence interval (CI) 1.24-1.58) and a 1.37-fold higher likelihood of obesity (OR 1.37, 95% CI 1.23-1.53) compared to those without psoriasis. These findings emphasize the systemic nature of psoriasis and its implications for metabolic health. In conclusion, this review underscores the importance of holistic management for psoriasis patients. Further research is warranted to explore underlying mechanisms and develop targeted therapeutic strategies. These findings contribute valuable insights to promote the overall well-being of individuals with psoriasis.

Real-world data show high efficacy of IL23 inhibitors guselkumab and risankizumab in psoriatic arthritis and difficult-to-treat areas

BACKGROUND

Psoriasis and psoriatic arthritis are chronic inflammatory skin and joint diseases requiring effective therapies. Although clinical studies have shown the efficacy of IL-23 inhibitors, real-world data are limited.

METHODS

We conducted a single-center retrospective Greek study enrolling patients with psoriatic arthritis and moderate-to-severe plaque psoriasis being treated at our multidisciplinary psoriasis outpatient clinic. Our aim was to investigate the efficacy and safety of IL-23 inhibitors guselkumab and risankizumab. Additionally, we sought to determine the clinical characteristics affecting treatment response. Primary endpoints were the evaluation of absolute Psoriasis Area and Severity Index (aPASI) and Disease Activity Index for Psoriatic Arthritis (DAPSA) at week 24.

RESULTS

Fifty-nine patients (55.9% male, 69.5% early onset) with a mean age of 51.7 years were included. Twenty-four patients (40.7%) had a concomitant psoriatic arthritis. Obesity was the main comorbidity (49.2%) with a mean body mass index (BMI) of 31.3 kg/m2 . Additional comorbidities were hypertension (44.1%), dyslipidemia (32.2%), and diabetes (18.6%). Only eight patients (13.6%) were naïve to previous systemic treatments, whereas 40 patients (67.8%) were bio-experienced. A statistically significant improvement of aPASI and DAPSA was demonstrated after 4, 16, and 24 weeks of treatment (P < 0.05). IL23 blockers were also efficacious in difficult-to-treat areas. Clinical outcome was affected from previous treatment with biologics. Treatment response was the same between guselkumab and risankizumab (P > 0.05).

CONCLUSION

This real-world study confirms the efficacy and safety of guselkumab and risankizumab in psoriatic arthritis and psoriasis reported from clinical trials.

"Input/output cytokines" in epidermal keratinocytes and the involvement in inflammatory skin diseases

Considering the role of epidermal keratinocytes, they occupy more than 90% of the epidermis, form a physical barrier, and also function as innate immune barrier. For example, epidermal keratinocytes are capable of recognizing various cytokines and pathogen-associated molecular pattern, and producing a wide variety of inflammatory cytokines, chemokines, and antimicrobial peptides. Previous basic studies have shown that the immune response of epidermal keratinocytes has a significant impact on inflammatory skin diseases. The purpose of this review is to provide foundation of knowledge on the cytokines which are recognized or produced by epidermal keratinocytes. Since a number of biologics for skin diseases have appeared, it is necessary to fully understand the relationship between epidermal keratinocytes and the cytokines. In this review, the cytokines recognized by epidermal keratinocytes are specifically introduced as "input cytokines", and the produced cytokines as "output cytokines". Furthermore, we also refer to the existence of biologics against those input and output cytokines, and the target skin diseases. These use results demonstrate how important targeted cytokines are in real skin diseases, and enhance our understanding of the cytokines.

Deciphering the Mechanism of Xijiao Dihuang Decoction in Treating Psoriasis by Network Pharmacology and Experimental Validation

Purpose

This study aims to confirm the efficacy of Xijiao Dihuang decoction (XJDHT), a classic prescription, in treating psoriasis and to explore the potential therapeutic mechanism.

Methods

For pharmacodynamic analysis, a mouse model of imiquimod cream (IMQ)-induced psoriasis was constructed. Active ingredients and genes of XJDHT, as well as psoriasis-related targets, were obtained from public databases. Intersecting genes (IGEs) of XJDHT and psoriasis were collected by Venn Diagram. A protein-protein interaction (PPI) network of IGEs is constructed through the STRING database. The Molecular Complex Detection (MCODE) and Cytohubba plug-ins of Cytoscape software were used to identified hub genes. In addition, we conducted enrichment analysis of IGEs using the R package clusterProfiler. Hub genes were validated via external GEO databases. The influence of XJDHT on Hub gene expression was examined by qPCR and ELISA, and molecular docking was used to evaluate the binding efficacy between active ingredients and hub genes.

Results

The results revealed that XJDHT possesses 92 potential genes for psoriasis, and 8 Hub genes were screened. Enrichment analysis suggested that XJDHT ameliorate psoriasis through multiple pathways, including AGE-RAGE, HIF-1, IL-17 and TNF signaling pathway. Validation data confirmed the differential expression of IL6, VEGFA, TNF, MMP9, STAT3, and TLR4. Molecular docking revealed a strong affinity between active ingredients and Hub genes. The efficacy of XJDHT in improving psoriatic lesions in model mice was demonstrated by PASI score and HE staining, potentially attributed to the down-regulation of VEGFA, MMP9, STAT3, TNF, and IL-17A, as evidenced by ELISA and qPCR.

Conclusion

This study employed network pharmacology and in vitro experiments to identify the potential mechanisms underlying the therapeutic effects of XJDHT on psoriasis, providing a new theoretical basis for its clinical application in the treatment of psoriasis.

Expert consensus on priority research gaps in dietary and lifestyle factors in hidradenitis suppurativa: a Delphi consensus study

Hidradenitis suppurativa (HS) is a debilitating systemic inflammatory disease with limited treatment options. Although management through dietary and lifestyle changes is a primary interest of the HS patient community, there is lack of consensus regarding recommendations due to the paucity of evidence. To establish the priority research gaps on this topic, we performed and moderated a Delphi consensus study by integrating expert opinions and the relevant literature. Based on a literature review, research questions on dietary and lifestyle interventions in HS were constructed. HS dietary and lifestyle research questions were sent to an expert panel, consisting of 22 international members, including dermatologists, dietitians, pharmacists, and endocrinologists. Voting on the research questions was conducted using a modified Delphi technique. The primary outcome measure was whether participants could reach consensus on the priority of each research question in the HS dietary and lifestyle factors. After three rounds of surveys investigating the relationships between HS and various diet and lifestyle factors, "BMI", "Obesity", and "Smoking", reached consensus as high priority research questions. Low research priorities per consensus included "effects of iron supplements", "effects of magnesium supplements", "alcohol consumption" and "limiting Brewer's yeast intake. Smoking and obesity were identified as important research questions, concurrent to the literature indicating their association with more significant impact on disease activity. By shedding light on high priority research questions, our study provides a roadmap for further research on dietary and lifestyle modifications in HS and will help determine evidence-based lifestyle and dietary recommendations for patients with HS.

Co-occurrence of non-alcoholic steatohepatitis exacerbates psoriasis associated with decreased adiponectin expression in a murine model

Introduction

Clinical studies have suggested a bidirectional association between non-alcoholic steatohepatitis (NASH) and psoriasis, affecting each other's development and severity. Here, we explored bidirectional causal linkages between NASH and psoriasis using a murine model.

Methods

NASH was induced in mice by streptozotocin injection at 2 days of age and by high-fat diet feeding (STAM™ model). Psoriasis was induced by topical application of imiquimod (IMQ) on the ear. The severities of liver damage and psoriatic skin changes were determined using histological analysis. Gene expression in the skin tissues was evaluated using quantitative PCR analysis. Serum cytokine levels were determined using enzyme-linked immunosorbent assay. To examine the innate immune responses of normal human epidermal keratinocytes (NHEKs), the cells were treated with interleukin (IL)-17A, tumor necrosis factor (TNF)-α, and AdipoRon, an adiponectin receptor agonist.

Results and Discussion

There were no differences in the degree of liver tissue damage (fat deposition, inflammation, and fibrosis) between NASH mice with and those without psoriasis. Conversely, the co-occurrence of NASH significantly augmented psoriatic skin changes, represented by epidermal hyperplasia, in psoriatic mice. Pro-inflammatory cytokines were expressed in the inflamed skin of psoriatic mice, and the expression of genes, especially Il23a, Il1b, Il36g, and Mip2, was significantly upregulated by the co-occurrence of NASH. The expression of keratinocyte activation marker genes Defb4b and Krt16 was also upregulated by the co-occurrence of NASH. The serum TNF-α and IL-17 levels were increased by the co-occurrence of NASH and psoriasis. The serum adiponectin levels decreased in NASH mice compared with that in non-NASH mice. In NHEK culture, TNF-α and IL-17A synergistically upregulated CXCL1, CXCL8, and IL1B expression. The upregulated pro-inflammatory gene expression was suppressed by AdipoRon treatment, reflecting the anti-inflammatory capacity of adiponectin.

Conclusion

The co-occurrence of NASH exacerbated psoriatic skin changes associated with increased serum inflammatory cytokine levels and decreased serum adiponectin levels. Combined with in vitro findings, increased inflammatory cytokine levels and decreased adiponectin levels likely promote innate immune responses in epidermal keratinocytes in psoriatic skin lesions. Overall, therapeutic intervention for co-occurring NASH is essential to achieve a favorable prognosis of psoriasis in clinical practice.

The Role of Diet in Children with Psoriasis: Emerging Evidence and Current Issues

Psoriasis is an immune-mediated inflammatory systemic disease with skin tropism and chronic relapsing course; it is associated with an increased cardiovascular risk and with many metabolic comorbidities, emerging during childhood in 22–33% of cases. Diet influences the presentation and the clinical course of inflammatory diseases, including psoriasis; in particular, it was shown that a Mediterranean, gluten-free, or low-calorie diet may positively affect disease control in adult patients with psoriasis and adequate pharmacological therapy. These three dietary regimens may play a role also in children with psoriasis. It has been demonstrated that pediatric psoriasis is associated with psychological stress, celiac disease, and obesity, which may be positively influenced by these dietary regimens, respectively. Therefore, the expertise of multiple health figures (gastroenterologists, nutritionists, pediatricians, dermatologists) is required to plan a tailor-made dietary strategy, ensuring good growth, through an adequate intake of essential micro- and macronutrients and, at the same time, impacting the pro-inflammatory biochemical profile and on the associated cardiovascular risk of psoriasis disease.

The Role of Adipokines in the Pathogenesis of Psoriasis

Psoriasis is a chronic and immune-mediated skin condition characterized by pro-inflammatory cytokines and keratinocyte hyperproliferation. Dendritic cells, T lymphocytes, and keratinocytes represent the main cell subtypes involved in the pathogenesis of psoriasis, while the interleukin-23 (IL-23)/IL-17 pathway enhances the disease progression. Human adipose tissue is an endocrine organ, which secretes multiple proteins, known as adipokines, such as adiponectin, leptin, visfatin, or resistin. Current evidence highlights the immunomodulatory roles of adipokines, which may contribute to the progression or suppression of psoriasis. A better understanding of the complexity of psoriasis pathophysiology linked with adipokines could result in developing novel diagnostic or therapeutic strategies. This review aims to present the pathogenesis of psoriasis and the roles of adipokines in this process.

Adiponectin, Leptin and Resistin in Patients with Psoriasis

Psoriasis is a common chronic, inflammatory skin disease characterised by keratinocyte hyperproliferation, parakeratosis, and T-cell infiltration. Adipose tissue has an endocrine function, producing an abundance of cytokines and adipokines. It has also been described that the major adipokines, leptin, resistin, and adiponectin, may be involved in the pathogenesis of psoriasis. The aim of the study was to examine the plasma levels of adiponectin, leptin, and resistin in patients with psoriasis and their correlations with disease activity parameters: Psoriasis Activity Severity Index (PASI), Dermatology Life Quality Index (DLQI), and Body Surface Area (BSA) index, as well as selected clinical parameters. The study included 53 patients with the plaque type and 31 healthy controls. The plasma concentrations of adiponectin were significantly lower in patients with psoriasis (p < 0.001) than in the control group. The plasma concentrations of leptin were higher in patients with psoriasis, however, due to high intra-patient variability of leptin plasma concentrations these differences did not reach statistical significance (p = 0.2). The plasma concentrations of resistin were significantly increased in patients with psoriasis compared to healthy controls (p = 0.02). There were no statistically significant correlations between adiponectin and leptin plasma concentrations and values of PASI, DLQI, and BSA. The resistin plasma concentrations correlated significantly with DLQI values. Additionally, we examined the correlations between adiponectin, leptin, and resistin plasma concentrations, and selected clinical parameters. Plasma concentrations of adiponectin correlated significantly with CRP values and ALT values. Leptin plasma concentrations correlated significantly with creatinine values. The results of our study confirm the role of adiponectin, leptin, and resistin in the pathogenesis of psoriasis.

Sphingosine 1-Phosphate as Essential Signaling Molecule in Inflammatory Skin Diseases

Sphingolipids are crucial molecules of the mammalian epidermis. The formation of skin-specific ceramides contributes to the formation of lipid lamellae, which are important for the protection of the epidermis from excessive water loss and protect the skin from the invasion of pathogens and the penetration of xenobiotics. In addition to being structural constituents of the epidermal layer, sphingolipids are also key signaling molecules that participate in the regulation of epidermal cells and the immune cells of the skin. While the importance of ceramides with regard to the proliferation and differentiation of skin cells has been known for a long time, it has emerged in recent years that the sphingolipid sphingosine 1-phosphate (S1P) is also involved in processes such as the proliferation and differentiation of keratinocytes. In addition, the immunomodulatory role of this sphingolipid species is becoming increasingly apparent. This is significant as S1P mediates a variety of its actions via G-protein coupled receptors. It is, therefore, not surprising that dysregulation in the signaling pathways of S1P is involved in the pathophysiological conditions of skin diseases. In the present review, the importance of S1P in skin cells, as well as the immune cells of the skin, is elaborated. In particular, the role of the molecule in inflammatory skin diseases will be discussed. This is important because interfering with S1P signaling pathways may represent an innovative option for the treatment of inflammatory skin diseases.

TRAPS mutations in Tnfrsf1a decrease the responsiveness to TNFα via reduced cell surface expression of TNFR1

Tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is an autoinflammatory periodic fever syndrome associated with heterozygous mutations in TNFRSF1A, which encodes TNF receptor type I (TNFR1). Although possible proinflammatory mechanisms have been proposed, most previous studies were performed using in vitro overexpression models, which could lead to undesirable inflammatory responses due to artificial overexpression. It is crucial to reproduce heterozygous mutations at physiological expression levels; however, such studies remain limited. In this study, we generated TRAPS mutant mice and analyzed their phenotypes. Three Tnfrsf1a mutant strains were generated by introducing T79M, G87V, or T90I mutation. T79M is a known mutation responsible for TRAPS, whereas G87V is a TRAPS mutation that we have reported, and T90I is a variant of unknown significance. Using these murine models, we investigated whether TRAPS mutations could affect the inflammatory responses in vivo and in vitro. We found that none of the mutant mice exhibited detectable inflammatory phenotypes under standard housing conditions for 1 year. Interestingly, TRAPS mutant (T79M and G87V) mice had reduced mortality rates after the administration of lipopolysaccharide (LPS) and D-galactosamine, which induce TNFα-dependent lethal hepatitis. Moreover, TRAPS mutations strongly suppressed the development of TNFα-mediated arthritis when crossed with human TNFα transgenic mice. In in vitro primary bone marrow-derived macrophage cultures, the T79M and G87V mutations attenuated the inflammatory responses to TNFα compared with the wild-type, whereas these mutations did not alter the responsiveness of these cells to LPS. The T90I mutant macrophages behaved similarly to wild type in response to LPS and TNFα. The TNFR1 levels were increased in whole-cell lysates of TRAPS mutant macrophages, whereas the cell surface expression of TNFR1 was significantly decreased in TRAPS mutant macrophages. Taken together, TRAPS mutations did not augment the inflammatory responses to TNFα and LPS; instead, they suppressed the response to TNFα via decreased cell surface expression of TNFR1. The stimulation of lymphotoxin-α, adenosine triphosphate, and norepinephrine in primary macrophages or various stimuli in murine splenocytes did not induce detectable inflammatory responses. In conclusion, TRAPS mutations suppressed responsiveness to TNFα, and TRAPS-associated inflammation is likely induced by unconfirmed disease-specific proinflammatory factors.

A Comparative Study of Xi’s Tendon Gangrene (Nonischemic Type of Diabetic Foot) and Gangrene (Diabetic Foot Ischemic Type)

Background. Diabetic foot gangrene refers to a lesion in which the tissue of the foot or lower extremities of diabetic patients is damaged, and the cause is the infection of peripheral blood vessels and neuropathy caused by diabetes. Objective. To compare the related indexes of blood glucose, inflammation, blood viscosity, and peripheral neuropathy between the nonischemic diabetic foot and ischemic diabetic foot, the same and different characteristics of the two different types of diabetic foot in pathogenesis were discussed and studied. Methods. A total of 122 patients with diabetic foot were selected from the Department of Vascular Medicine, Shanghai Hospital of Integrated Traditional Chinese and Western Medicine, including 61 cases of ischemic type and 61 cases of nonischemic type. The differences in blood glucose, inflammation, blood supply, and peripheral neuropathy between the nonischemic diabetic foot and ischemic diabetic foot were compared to explore their different characteristics. Results. The blood glucose index, inflammatory index, and plasma fibrinogen in patients with nonischemic diabetic foot were significantly higher than those in patients with ischemic diabetic foot ( $P<0.05$ ). The patients with ischemic diabetic foot were higher in age and blood lipid index than those with the nonischemic diabetic foot ( $P<0.05$ ), while having no significant difference in platelet count, plasma viscosity, hematocrit, and end products of glycation (AGEs). Conclusion. The nonischemic diabetic foot is mainly infective necrosis, and the ischemic type is ischemic necrosis. The former occurs in the middle-aged and elderly with good blood supply between 40 and 60 years old, while the latter occurs in the elderly with the severe vascular disease over 60 years old. The blood glucose level of nonischemic patients is significantly higher than that of ischemic patients, but it has little to do with the course of diabetes.