The role of the platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio in the prediction of length and cost of hospital stay in patients with infected diabetic foot ulcers: A retrospective comparative study

[Development and Validation of a Risk Prediction Model for Prolonged Hospitalization in Patients With Diabetic Foot Ulcers]

Objective

To investigate the risk factors associated with prolonged hospitalization in patients diagnosed with diabetic foot ulcers (DFU), to develop a predictive model, and to conduct internal validation of the model.

Methods

The clinical data of DFU patients admitted to West China Hospital, Sichuan University between January 2012 and December 2022 were retrospectively collected. The subjects were randomly assigned to a training cohort and a validation cohort at a ratio of 7 to 3. Hospital stays longer than 75th percentile were defined as prolonged length-of-stay. A thorough analysis of the risk factors was conducted using the training cohort, which enabled the development of an accurate risk prediction model. To ensure robustness, the model was internally validated using the validation cohort.

Results

A total of 967 inpatients with DFU were included, among whom 245 patients were identified as having an extended length-of-stay. The training cohort consisted of 622 patients, while the validation cohort comprised 291 patients. Multivariate logistic regression analysis revealed that smoking history (odds ratio [OR]=1.67, 95% confidence interval [CI], 1.13 to 2.48, P=0.010), Wagner grade 3 or higher (OR=7.13, 95% CI, 3.68 to 13.83, P<0.001), midfoot ulcers (OR=1.99, 95% CI, 1.07 to 3.72, P=0.030), posterior foot ulcers (OR=3.68, 95% CI, 1.83 to 7.41, P<0.001), multisite ulcers (OR=2.91, 95% CI, 1.80 to 4.69, P<0.001), wound size≥3 cm2 (OR=2.00, 95% CI, 1.28-3.11, P=0.002), and white blood cell count (OR=1.11, 95% CI, 1.05 to 1.18, P<0.001) were associated with an increased risk of prolonged length of stay. Additionally, a nomogram was constructed based on the identified risk factors. The areas under the receiver operating characteristic (ROC) curves for both the training cohort and the validation cohort were 0.782 (95% CI, 0.745 to 0.820) and 0.756 (95% CI, 0.694 to 0.818), respectively, indicating robust predictive performance. Furthermore, the calibration plot demonstrated optimal concordance between the predicted probabilities and the observed outcomes in both the training and the validation cohorts.

Conclusion

Smoking history, Wagner grade≥3, midfoot ulcers, posterior foot ulcers, multisite ulcers, ulcer area≥3 cm2, and elevated white blood cell count are identified as independent predictors of prolonged hospitalization. Therefore, it is imperative that clinicians conduct a comprehensive patient evaluation and implement appropriate diagnostic and therapeutic strategies to effectively shorten the length of stay for DFU patients.

Relationship between systemic immune inflammation index and amputation in patients with diabetic foot ulcer

AIM

The systemic immune inflammation index (SII) is a cost-effective biomarker calculated by lymphocyte, neutrophil and platelet counts and is currently being studied in various diseases. Since there is no study examining the relationship between SII and diabetic foot ulcers (DFU) in the literature, our aim was to investigate the relationship between SII and amputation rate in DFU.

METHODS

Type 2 DM 511 patients with DFU were screened from 2017 to 2021. Laboratory data obtained on the first day of hospitalization were considered. Platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR) and SII were calculated from routine blood count. Participants were divided into two groups as amputation (Group 1) and non-amputation (Group 2).

RESULTS

Amputation rate was 18.8%. The A1c (8.80 (3.26) % vs. 9.52 (3.10) %, p = 0.007) and HGB (10.17 ± 2.16 g/dL vs. 12.05 ± 2.20 g/dL, p < 0.001) levels, and lymphocyte count (1.81 (1.16) vs. 2.05 (1.11), p = 0.015) were significantly lower in Group 1 than Group 2. The counts of WBC (14.01 (9.16) × 109/L vs. 10.41 (5.82) × 109/L), PLT (393.35 (196.98) × 109/L vs. 312.05 (141.33) × 109/L), neutrophil (11.52 (8.75) × 109/L vs. 6.93 (5.96) × 109/L), PLR (226.04 (159.24) × 109/L vs. 153.12 (101.91) × 109/L), NLR (6.64 (6.93) vs. 3.34 (3.99)) and SII (2505.86 (3957.47) × 109/L vs. 1092.50 (1476.08) × 109/L), and the levels of CRP (14.12 (12.66) mg/dL vs. 3.86 (12.63) mg/dL) and ESR (87.50 (50.50) mm/h vs. 63.00 (57.25) mm/h) were significantly higher in Group 1 than Group 2 (all p < 0.001). AUC of ROC analysis of PLR was 0.666 (95% CI, 0.604-0.728), NLR was 0.695 (95% CI, 0.638-0.752) and SII was 0.716 (95% CI, 0.661-0.772) for the predicting of amputation and the SII had the best AUC with 67.4% sensitivity and 63.3%specificty.

CONCLUSION

SII is a cost-effective and readily available marker, but alone may not be sufficient to predict the risk of amputation in DFU. In our results, the predictive role of SII alone or with other markers for future DFU and its role in predicting other chronic diabetic complications will be evaluated in extensive studies.

Significance of Neutrophil to Lymphocyte Ratio (NLR) and Platelet Lymphocyte Ratio (PLR) in Diabetic Foot Ulcer and Potential New Therapeutic Targets

Diabetic foot ulcer (DFU) is a well-known complication of diabetes and a significant burden on the national health systems. The neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio are inexpensive and easily accessible biomarkers that have proved to be useful in several inflammatory, infectious and cardiovascular diseases. We carried out a comprehensive review examining the association of NLR and PLR with the onset and progression of DFU. PLR and NLR were significantly increased in patients with DFU, compared with a control group of T2DM patients without DFU, and correlate well with DFU severity, evaluated by Wagner and IWGDF grading scales. In patients with diabetic foot infections (DFI), elevated NLR and PLR were correlated with osteomyelitis, increased risk of amputation, and septic complications. The significance of the elevated value of these biomarkers in DFU is related to chronic hyperglycemia and low-grade systemic inflammation, atherosclerotic and vascular complications, and also the associated septic factor. Serial, dynamic follow-up can provide useful information in planning and monitoring DFU treatment, as well as in risk stratification of these vulnerable patients. Further randomized studies are needed to set the cut-off values with clinical significance.

The impact of inflammatory biomarkers on amputation rates in patients with diabetic foot ulcers

Diabetic Foot Ulcers (DFUs) are a major complication of diabetes, often leading to amputation. Understanding the relationship between haematological inflammatory markers and the incidence of amputation in DFU patients with infectious complications is crucial for improving management and outcomes. This retrospective study, conducted from May 2020 to October 2022, involved 109 patients with DFUs, categorised into amputation (AM) and non-amputation (NAM) groups. Patients were evaluated for various factors, including demographic data, DFU duration, and blood parameters such as haemoglobin A1c (HbA1c), haemoglobin (Hb), albumin (ALB), white blood cell count (WBC), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), C-reactive protein (CRP), platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR). Statistical analyses were performed using independent sample t-tests, Mann-Whitney U test and logistic regression. The univariate analysis showed no significant difference in BMI, DM duration or DFU duration between groups. However, significant differences were noted in PCT, Hb, ESR, ALB, HbA1c and WBC levels, and in inflammatory ratios (NLR, PLR and LMR). Multivariate logistic regression identified CRP, NLR and PLR as independent risk factors for amputation. The study highlights CRP, PLR and NLR as key independent risk factors for amputation in patients with DFUs. These easily obtainable markers from routine blood tests can effectively aid in predicting the risk of osteomyelitis and amputation, enhancing clinical decision making and patient care strategies.

Diabetes Mellitus and Prevalence of Other Comorbid Conditions: A Systematic Review

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by elevated blood glucose levels, severity continues to rise worldwide. This systematic review seeks to examine the prevalence of diabetes and its associated comorbid conditions, aiming to provide insights into the multifaceted impact of diabetes on a broader scale. DM exhibits a positive correlation with advancing age, and it's strongly influenced by genetic predisposition. In recent years, there has been a discernible global increase in the prevalence of type 1 diabetes (T1D), as evidenced by extensive epidemiological studies. Individuals with DM frequently have a positive familial history, and the presence of DM in both parents or solely the mother significantly amplifies genetic susceptibility. Moreover, non-genetic factors, such as acute psychological stressors, obesity, pregnancy, and smoking play a pivotal role in the development of DM. Notably, urinary tract infections (UTIs) are a common comorbidity in patients with type 2 diabetes (T2D) and all patients with T1D. T2D is prevalent, particularly among females, and its incidence rises with age. UTIs are prevalent among individuals with diabetes, particularly females, with Escherichia coli (E. coli) isolates being the primary etiological agents responsible for UTI inflammation. Insulin resistance is a common feature in both prediabetes and prehypertension, serving as a precursor to these conditions. The increasing incidence of T2D in regions with high tuberculosis (TB) prevalence emphasizes the significance of understanding DM as a substantial TB risk factor. DM is associated with a threefold elevation in TB risk and a twofold increase in unfavorable outcomes during TB treatment. Notably, the global prevalence of DM has led to a larger population of TB patients with comorbid DM than TB patients coinfected with HIV. Diabetes and sepsis contribute significantly to worldwide morbidity and mortality, with diabetic individuals experiencing more post-sepsis complications and increased mortality. The coexistence of hypertension and T2D is a common comorbidity, with hypertension incidence being twice as high among individuals with diabetes compared to those without, often linked to insulin resistance and a heightened risk of diabetes onset.

The Preoperative Neutrophil-Lymphocyte Ratio Is an Independent Predictive Factor in Predicting 1-Year Mortality in Amputated Diabetic Foot Patients

In this study, we aimed to evaluate the efficacy of neutrophil/lymphocyte ratio values in preoperative blood tests of patients amputated due to diabetic foot in predicting 1-year mortality. We assumed that the neutrophil/lymphocyte ratio predicted 1-year mortality in these patients. The inclusion criteria were as follows: to be diagnosed with diabetic foot, being >18 years of age, having a confirmed type 1 or type 2 diabetes mellitus diagnosis, stage 3 to 5 Wagner ulcers, and having at least 1 year of follow-up. The patients with acute traumatic injuries observed in less than 1 week, traumatic amputations, and nondiabetic amputations, and those whose data could not be obtained were excluded from the study. After the exclusion, 192 patients were included in the study. Age (p < .001), low preoperative hemoglobin (p = .024), high preoperative neutrophil (p < .001), low preoperative lymphocyte (p = .023), low preoperative albumin (p < .001), high preoperative neutrophil-to-lymphocyte ratio (p < .001), major amputation (p = .002), and were related to 1-year mortality. According to these results: (1) it was observed that a preoperative neutrophil/lymphocyte ratio value over 5.75 increases the risk of death 1.1 times and (2) it was observed that a preoperative albumin value under 2.67 increases the risk of death 5.74 times. In conclusion, the age, preoperative neutrophil/lymphocyte ratio, and albumin values of patients planning to undergo amputation surgery can be independent predictive factors in predicting 1-year mortality.

Urinary tract infection in patients with diabetes mellitus and the role of parental genetics in the emergence of the disease

This study aimed to assess the role of paternal genetics in the development of diabetic mellitus (DM) and determine the impact of DM on the urinary system by investigating the percentage of patients with urinary tract infection (UTI). The study included 100 people with DM; their ages ranged from 5 to 83 years. The DM and blood sugar levels were diagnosed clinically and at a laboratory in Al-Zahra Teaching Hospital and the outpatient clinics. The age, gender, and causes of DM and the family history of diabetes were reported. Isolation and identification of bacterial species were made depending on culture media and biochemical tests. The average age of patients was 47.7±5.5, and most of them were female (67%). The incidence of DM increased with age, and the main cause of DM was likely to be a genetic predisposition (family history), where 32% of patients appeared to have a positive family history and the presence of DM in both parents or only the mother had a significant role in increasing the genetic predisposition of developing DM. Among the non-genetic causes of DM, the most common was exposure to sudden psychological or nervous shock (41%). Obesity also had an important role in the development of diabetes, and also pregnancy and smoking. Moreover, 66% of patients with type 2 DM and all with type 1 DM suffered from UTIs. The main causative agents were E. coli (60%) and Proteus spp. (13%). The majority of patients suffering from UTIs (73%) were females. In conclusion, type 2 DM is the most common, especially in females, and increases with age. The main cause of DM was family genetic predisposition and sudden shocks. The current study also showed that most diabetic patients suffered from UTIs, especially females, and the main causes of UTI inflammation are E. coli isolates.

Prognostic Role of Subsequent Thrombocytopenia in Necrotizing Fasciitis Without Liver Disease

BACKGROUND

Necrotizing fasciitis (NF) is a life-threatening disease with a fulminant presentation. Although early diagnosis can be aided by combining physical examination, the Laboratory Risk Indicator for Necrotizing Fasciitis score, and computed tomography, a mortality rate of 30% is still reported. In the modern times, an economical and efficient biomarker for predicting mortality in NF patients is still lacking. Platelet count is typically measured in routine blood tests and aids in predicting disease severity. We aimed to clarify the role of platelet count as a predictive factor for aspects of prognosis, such as mortality and surgical outcomes, in patients with NF.

METHODS

We identified 285 patients with NF between 2018 and 2020 in a single medical center in southern Taiwan. Medical records were collected for the evaluation of patients with thrombocytopenia. Univariate and multivariate analyses were performed for different outcomes.

RESULTS

We included 115 patients with confirmed diagnoses of NF. Twelve patients died with a mortality rate of 10.4%. Patients with thrombocytopenia exhibited a higher mortality rate (20.9% vs 4.2%, P = 0.006), more shock episodes (51.2% vs 11.1%, P < 0.001), higher intensive care unit admission rate (46.5% vs 13.9%, P < 0.001), and longer hospital length of stay (37.49 ± 24.12 days vs 28.82 ± 14.63 days, P = 0.037) than those without thrombocytopenia. All patients infected with Vibrio species exhibited thrombocytopenia. In multivariate analysis, independent risk factors for mortality were thrombocytopenia (odds ratio, 4.57; 95% confidence interval, 1.08-19.25) and single gram-negative bacterial culture from the wound (odds ratio 6.88; 95% confidence interval, 1.58-29.96).

CONCLUSIONS

In patients with NF and subsequent thrombocytopenia, a higher mortality rate, greater numbers of shock episodes, higher demand for intensive care unit, and longer hospital length of stay were observed than in those without thrombocytopenia. In patients with NF, platelet count is a valuable and economic indicator of prognosis. Once thrombocytopenia developed in patients with necrotizing fasciitis, aggressive antibiotic treatment and surgical management are required to improve the chances of recovery.

Diabetic Wound-Healing Science

Diabetes mellitus is an increasingly prevalent chronic metabolic disease characterized by prolonged hyperglycemia that leads to long-term health consequences. It is estimated that impaired healing of diabetic wounds affects approximately 25% of all patients with diabetes mellitus, often resulting in lower limb amputation, with subsequent high economic and psychosocial costs. The hyperglycemic environment promotes the formation of biofilms and makes diabetic wounds difficult to treat. In this review, we present updates regarding recent advances in our understanding of the pathophysiology of diabetic wounds focusing on impaired angiogenesis, neuropathy, sub-optimal chronic inflammatory response, barrier disruption, and subsequent polymicrobial infection, followed by current and future treatment strategies designed to tackle the various pathologies associated with diabetic wounds. Given the alarming increase in the prevalence of diabetes, and subsequently diabetic wounds, it is imperative that future treatment strategies target multiple causes of impaired healing in diabetic wounds.

T-Natural Killers and Interferon Gamma/Interleukin 4 in Augmentation of Infection in Foot Ulcer in Type 2 Diabetes

BACKGROUND

The link between immune system and type 2 diabetes mellitus (T2DM) pathogenesis attracted attention to demonstrate the role of immune cells and their secreted cytokines in T2DM development and its subsequent foot complications.

OBJECTIVE

To investigate the relation between T Natural killer cell (TNK) %, Interleukin 4 (IL4) and Interferon gamma (IFN-γ) and diabetic foot infection (DFI) development in patients with diabetic foot ulcer (DFU).

PATIENTS AND METHODS

Ninety patients with diabetes were included in this work, divided as T2DM group (n=30), DFU group (n=30), and DFI group (n=30). TNK% was detected using flow cytometry. Serum IL4 and IFN-γ were measured by ELISA. Diabetes biochemical parameters were also analyzed.

RESULTS

Significant decrease was detected in TNK% and IFN-γ in DFI group compared to other 2 groups (P<0.001). Significant decrease was detected in serum levels of IL4 in DFI group compared to T2DM group (P=0.006). IFN-γ/IL4 was significantly decreased in DFI compared to DFU group (P=0.020). There was a significant correlation of TNK% with both IL4 and IFN-γ (r=0.385, P<0.001; r=0.534, P<0.001, respectively). Significant negative correlation of TNK% with HbA1c and LDL was revealed (r=-0.631, P<0.001; and r=-0.261, P=0.013, respectively), while a positive correlation was seen with HDL (r=0.287, P=0.006). A significant negative correlation of IL4 with HbA1c  was found (r=-0.514, P<0.001;. As for IFN-γ, a significant negative correlation with HbA1c and LDL was detected (r=-0.369, P< 0.001; r=-0.229, P=0.030). TNK % and IFN-γ level showed negative correlations with disease duration/year (r=-0.546, P< 0.001; r=-0.338, P=0.001,respectively).

CONCLUSION

Decline in TNK frequency has essential role in T2DM pathogenesis and subsequent foot complications. Downregulation of TNK% and IFN-γ level have potential roles in predicting infection of diabetic ulcer and are correlated with disease duration.

[Biochemical analysis between common type and critical type of COVID-19 and clinical value of neutrophil/lymphocyte ratio]

OBJECTIVE

To identify the key biochemical indicators that affect the clinical type and outcomes of COVID-19 patients and explore the application of neutrophil/lymphocyte ratio (NLR) in COVID-19.

METHODS

Ninety-three patients with confirmed diagnosis of COVID-19 admitted in Ezhou Central Hospital from February to April in 2020 were analyzed. Among them, 43 patients were selected from Intensive Care Unit (ICU) with the diagnosis of critical type of COVID-19, and 50 cases of common type were selected from the Department of Respiratory Medicine. The baseline data, blood routine test and biochemical indexes of the patients were collected on the first day of admission. NLRs of the patients were calculated, and COX survival analysis according to the NLR 4-category method was performed. The patients' outcomes were analyzed with receiver operating curves (ROCs). The patients were divided into two groups according to NLR cutoff value for comparison of the biochemical indexes. Based on the patients' outcomes, NLR cutoff value classification and clinical classification, multiple binary logistics regression was performed to screen the key variables and explore their significance in COVID-19.

RESULTS

The NLR four-category method was not applicable for prognostic evaluation of the patients. The cut-off value of NLR for predict the prognosis of COVID-19 was 11.26, with a sensitivity of 0.903 and a specificity of 0.839; the laboratory indicators of the patients with NLR &lt; 11.26 were similar to those in patients of the common type; the indicators were also similar between patients with NLR≥11.26 and those with critical type COVID-19. NLR, WBC, NEUT, PCT, DD, BUN, TNI, BNP, and LDH had significant effects on the clinical classification and outcome of the patients (P &lt; 0.05); Cr, Ca, PH, and Lac had greater impact on the outcome of the patients (P &lt; 0.05), while Na, PCO₂ had greater impact on the clinical classification of the patients (P &lt; 0.05).

CONCLUSIONS

NLR can be used as an important reference for clinical classification, prognostic assessment, and biochemical abnormalities of COVID-19. Patients of critical type more frequently have bacterial infection with more serious inflammatory reactions, severer heart, lung and kidney damages, and much higher levels of DD and LDH than those of the common type. NLR, NEUT, DD, TNI, BNP, LDH, Ca, PCT, PH, and Lac have obvious influence on the prognosis of COVID-19 and should be observed dynamically.