Correlation of ankle-wrist pressure index with ankle-brachial pressure index to assess lower limb perfusion in diabetic foot ulcer: a pilot study.

OBJECTIVE: The presence of peripheral artery disease (PAD) in patients with diabetic foot ulcers (DFUs) is a significant risk factor for chronicity and amputation. Ankle-brachial pressure index (ABPI) is a screening tool for PAD. Brachial systolic pressure measurement, used as a denominator in the calculation of ABPI, produces inaccurate results in patients with obesity and the presence of heavy clothing. The wrist, however, is easily accessible, and the ankle-wrist pressure index (AWPI), if comparable with ABPI, may be useful in screening selected patients. This study aimed to assess the efficacy of AWPI in diagnosing perfusion in DFUs and compare it to ABPI in patients with DFUs. METHOD: ABPI and AWPI were calculated by measuring systolic blood pressure in the arteries of the ankle, arm and wrist with a handheld Doppler. Actual perfusion was determined by the presence or absence of PAD by duplex ultrasound. RESULTS: A total of 46 lower extremities in 41 patients were studied. The prevalence of PAD was 61%. Duplex ultrasound confirmed that the sensitivity of ABPI and AWPI in detecting PAD in patients with DFUs was 67.9% and 71.4% respectively, whereas the specificity of ABPI and AWPI was 94.4% and 88.9% respectively. On receiver operating characteristic analysis, the area under the curve of ABPI and AWPI was 0.804 and 0.795, respectively. A statistically significant positive correlation between ABPI and AWPI was found (r=0.986; p<0.001). CONCLUSION: There was a good correlation between ABPI and AWPI over a wide range of values. ABPI and AWPI may have a similar role in predicting perfusion in patients with DFUs. AWPI could be used in place of ABPI in selected patients in whom measuring ABPI may be difficult. DECLARATION OF INTEREST: The authors have no conflicts of interest to declare.

Dynamic Microcirculation Characteristics of Plantar Skin Under Metatarsal Head of Human Foot in Response to Life-Like Pressure Stimulus.

OBJECTIVE: Diabetic foot ulcer (DFU) is a severe complication with high mortality. High plantar pressure and poor microcirculation are considered main causes of DFU. The specific aims were to provide a novel technique for real-time measurement of plantar skin blood flow (SBF) under walking-like pressure stimulus and delineate the first plantar metatarsal head dynamic microcirculation characteristics because of life-like loading conditions in healthy individuals. METHODS: Twenty young healthy participants (14 male and 6 female) were recruited. The baseline (i.e., unloaded) SBF of soft tissue under the first metatarsal head were measured using laser Doppler flowmetry (LDF). A custom-made machine was utilized to replicate daily walking pressure exertion for 5 min. The exerted plantar force was adjusted from 10 N (127.3 kPa) to 40 N (509.3 kPa) at an increase of 5 N (63.7 kPa). Real-time SBF was acquired using the LDF. After each pressure exertion, postload SBF was measured for comparative purposes. Statistical analysis was performed using the R software. RESULTS: All levels of immediate-load and postload SBF increased significantly compared with baseline values. As the exerted load increased, the postload and immediate-load SBF tended to increase until the exerted load reached 35 N (445.6 kPa). However, in immediate-load data, the increasing trend tended to level off as the exerted pressure increased from 15 N (191.0 kPa) to 25 N (318.3 kPa). For postload and immediate-load SBF, they both peaked at 35 N (445.6 kPa). However, when the exerted force exceeds 35 N (445.6 kPa), both the immediate-load and postload SBF values started to decrease. CONCLUSIONS: Our study offered a novel real-time plantar soft tissue microcirculation measurement technique under dynamic conditions. For the first metatarsal head of healthy people, 20 N (254.6 kPa)-plantar pressure has a fair microcirculation stimulus compared with higher pressure. There might be a pressure threshold at 35 N (445.6 kPa) for the first metatarsal head, and soft tissue microcirculation may decrease when local pressure exceeds it.

[Evaluation of revascularization efficiency using near-infrared oximetry in patients with diabetic foot syndrome]. / Otsenka effektivnosti revaskulyarizatsii u patsientov s sindromom diabeticheskoi stopy metodom parainfrakrasnoi oksimetrii.

OBJECTIVE: To evaluate prognostic significance of tissue oximetry in healing of trophic defects in patients with diabetic foot syndrome (DFS) after endovascular revascularization. MATERIAL AND METHODS: In 42 patients with DFS, tissue oximetry was performed in angiosome projection with the FORE-SIGHT MC-2000 (CASMED) device before and the next day after revascularization of lower limb arteries. The 1st group included 30 patients with wound healing throughout 3 months, the 2nd group included 12 patients with amputation or no healing of trophic defects. RESULTS: Direct revascularization was more common in the 1st group (p=0.001). On the day after intervention, oxygen saturation (StO2) increased in all angiosomes in both groups (p<0.05). StO2 increment differed significantly between groups in all angiosomes except for point I (p<0.05). According to ROC analysis, StO2 increment by 4.5% in absolute values and 7.9% in percentage leads to trophic defect healing within 3 months (sensitivity and specificity were 76.7% and 66.7% for absolute values, 80% and 58.3% for percentage, respectively). CONCLUSION: Evaluation of StO2 in target angiosome may be valuable to predict trophic defect healing after endovascular surgery.

Undiagnosed and Untreated Peripheral Complications of Diabetes: Findings from a Pilot Study on Diabetes-Related Foot Diseases (DFD) in Patients with Glycemic Disorders.

BACKGROUND Diabetes-related foot disease (DFD) is a serious complication of diabetes, increasing the risk of amputation. Coimplications are preventable, but most diabetics do not receive proper screening and treatment, despite indications. This study was a pilot screening of diabetes-related foot disease in a group of people with glycemic disorders. MATERIAL AND METHODS We recruited 143 volunteers over 40 years of age. In the final analysis, we included 85 people diagnosed with glycemic disorders (diabetes or prediabetes), for whom we performed a total of 170 foot measurements. We screened for peripheral artery disease using: foot pulse, ankle-brachial index (manual and automatic), toe-brachial index, and transcutaneous oxygen pressure (TcPO2). To screen for diabetic peripheral neuropathy, we used indicators of loss of protective sensation: pressure perception and temperature perception, and plantar pressure distribution. RESULTS A history of diabetes was reported by 26 (30.6%) of the subjects. Disorders of at least 1 foot occurred in 20 (66.7%) subjects with diagnosed diabetes and in 10 (17%) subjects declaring no diabetes. Higher risk and DFD category were correlated with duration of diabetes (r=0.68, p=0.007), glycemic levels (r=0.56, p=0.001), age (r=0.57, p=0.007), and the presence of other diabetes complications. The best predictor of risk in DFD was manual ABI, p=0.001; followed by automatic ABI, p=0.006. CONCLUSIONS Our results showed that peripheral complications of diabetes, such as DFD, often remain undiagnosed and untreated despite the high risk of developing ulcers. There is a need for multi-center screening studies.

Plantar pressure reduction in the heel region through self-adjusting insoles with a heel cup in standard and individualized rocker shoes.

BACKGROUND: Effectiveness of therapeutic footwear in reducing peak pressure in persons with diabetes and loss of protective sensation to prevent diabetic foot ulcers varies due to manual production and possible changing foot structure. A previous two-way approach to address this issue, featuring individualized 3D-printed rocker midsoles and self-adjusting insoles, proved effective in the forefoot but less in the heel. To address this, new insoles incorporating a heel cup are developed. METHODS: In-shoe pressure was measured, while persons with diabetes and loss of protective sensation with high peak pressure (≥ 200 kPa) in the heel walked on a treadmill with control and individualized rocker shoe paired with control and new insole. FINDINGS: Generalized estimating equations revealed significant decrease in peak pressure in the proximal heel with the new insole alone and combined with rocker shoe compared to rocker shoe alone. For the distal heel, significant decrease in peak pressure is shown with the combination of new insole and rocker shoe compared to control shoe. For the forefoot and toes (excluding hallux) significant decrease in peak pressure is shown using the rocker shoe alone or combined with the heel cup compared to control shoe. INTERPRETATION: The new insole paired with rocker shoe is effective in reducing peak pressure in the distal heel. To have similar (or more) success in proximal heel, one could replace the rocker midsole with more compliant materials. The rocker shoe used separately or combined with a heel cup effectively reduces the peak pressure in the forefoot and other toes.

Treating chronic wounds in an acute care setting: the forgotten diagnosis.

BACKGROUND: Chronic wounds include lower extremity ulcers, diabetic foot ulcers, and pressure injuries, and can take months or years to heal. Wounds place a high burden on outpatient and inpatient care settings. This burden is expected to increase markedly in the United States as the population ages and with increased rates of diabetes, obesity, and COVID-19. PURPOSE: To articulate the effect of chronic, hard-to-heal wounds on acute care facilities, and how a few days of inpatient care can have a significant effect on the healing trajectory. METHODS: An expert panel of 7 members, all with extensive knowledge and experience in the assessment and treatment of chronic wounds in an acute care setting, was convened in March 2022. The panel discussed the role of hospitals as part of the longer-term healing pathway of chronic wounds. RESULTS: Chronic wounds have a significant effect on hospitals that includes unseen costs, bed occupancy, demands on bedside nurses, and wound complications that lead to extended stays or readmissions. A successful inpatient wound program offers appropriate identification of previously undiagnosed wounds, elevation of bedside care through simplified protocols, quickly and easily understood education and easy dressing selection, and comprehensive discharge planning with a multidisciplinary team for continuity of care and reduced risk of readmission. CONCLUSION: Hospitals can play a key role in the management of chronic wounds, thus reducing the effect on each facility and the wider care network.

Effects of individually optimized rocker midsoles and self-adjusting insoles on dynamic stability in persons with diabetes mellitus and neuropathy.

BACKGROUND: Persons with diabetic peripheral neuropathy (DPN) may face challenges such as balance issues due to reduced somatosensory feedback and an increased risk of developing diabetic foot ulcers (DFUs) due to increased plantar pressure. Pressure reducing footwear is thought to further impair balance. We introduced 3D-printed rocker midsoles and self-adjusting insoles that are able to reduce elevated plantar pressure values and aimed to prevent balance deterioration. However, their effect on the balance during walking (dynamic stability) is not analyzed yet. RESEARCH QUESTION: Is dynamic stability of persons with DPN impaired compared to healthy individuals and what is the effect of the 3D-printed rocker midsoles and self-adjusting insoles on the dynamic stability in this population? METHODS: Dynamic stability, specifically the margins of stability (MOS) in the anterior-posterior (AP) and medio-lateral (ML) direction, was measured in ten healthy and nineteen persons with DPN. Independent-samples t-test was applied to analyze the difference in the MOS between groups. One-way repeated measures analyses of variance (ANOVA) was conducted to test the difference between the therapeutic footwear combinations within the DPN group. RESULTS: There is no significant difference between the healthy and DPN group in MOS-AP. MOS-ML is significantly larger in DPN compared to the healthy participants. Using the self-adjusting insole shows a significantly lower (negative) MOS-AP compared to when using a rocker shoe within the DPN group. SIGNIFICANCE: This study provides valuable information on whether DPN and our therapeutic footwear have a negative effect on the dynamic stability. DPN does not have a negative effect on dynamic stability in the AP direction. For the ML direction, DPN seems to cause larger MOS-ML by likely using a compensation strategy (e.g., wider steps) while our experimental footwear does not further impair the MOS-ML.

Wearable laser Doppler flowmetry for non-invasive assessment of diabetic foot microcirculation: methodological considerations and clinical implications.

Significance: Type 2 diabetes mellitus (T2DM) is a global health concern with significant implications for vascular health. The current evaluation methods cannot achieve effective, portable, and quantitative evaluation of foot microcirculation. Aim: We aim to use a wearable device laser Doppler flowmetry (LDF) to evaluate the foot microcirculation of T2DM patients at rest. Approach: Eleven T2DM patients and twelve healthy subjects participated in this study. The wearable LDF was used to measure the blood flows (BFs) for regions of the first metatarsal head (M1), fifth metatarsal head (M5), heel, and dorsal foot. Typical wavelet analysis was used to decompose the five individual control mechanisms: endothelial, neurogenic, myogenic, respiratory, and heart components. The mean BF and sample entropy (SE) were calculated, and the differences between diabetic patients and healthy adults and among the four regions were compared. Results: Diabetic patients showed significantly reduced mean BF in the neurogenic (p=0.044) and heart (p=0.001) components at the M1 and M5 regions (p=0.025) compared with healthy adults. Diabetic patients had significantly lower SE in the neurogenic (p=0.049) and myogenic (p=0.032) components at the M1 region, as well as in the endothelial (p<0.001) component at the M5 region and in the myogenic component at the dorsal foot (p=0.007), compared with healthy adults. The SE in the myogenic component at the dorsal foot was lower than at the M5 region (p=0.050) and heel area (p=0.041). Similarly, the SE in the heart component at the dorsal foot was lower than at the M5 region (p=0.017) and heel area (p=0.028) in diabetic patients. Conclusions: This study indicated the potential of using the novel wearable LDF device for tracking vascular complications and implementing targeted interventions in T2DM patients.

Factors Influencing Wound Healing in Diabetic Foot Patients.

Background and objectives: Diabetic foot stands out as one of the most consequential and devastating complications of diabetes. Many factors, including VIPS (Vascular management, Infection management, Pressure relief, and Source of healing), influence the prognosis and treatment of diabetic foot patients. There are many studies on VIPS, but relatively few studies on "sources of healing". Nutrients that affect wound healing are known, but objective data in diabetic foot patients are insufficient. We hypothesized that "sources of healing" would have many effects on wound healing. The purpose of this study is to know the affecting factors related to the source of healing for diabetic foot patients. Materials and Methods: A retrospective review identified 46 consecutive patients who were admitted for diabetic foot management from July 2019 to April 2021 at our department. Several laboratory tests were performed for influencing factor evaluation. We checked serum levels of total protein, albumin, vitamin B, iron, zinc, magnesium, copper, Hb, HbA1c, HDL cholesterol, and LDL cholesterol. These values of diabetic foot patients were compared with normal values. Patients were divided into two groups based on wound healing rate, age, length of hospital stay, and sex, and the test values between the groups were compared. Results: Levels of albumin (37%) and Hb (89%) were low in the diabetic foot patients. As for trace elements, levels of iron (97%) and zinc (95%) were low in the patients, but levels of magnesium and copper were usually normal or high. There were no differences in demographic characteristics based on wound healing rate. However, when compared to normal adult values, diabetic foot patients in our data exhibited significantly lower levels of hemoglobin, total protein, albumin, iron, zinc, copper, and HDL cholesterol. When compared based on age and length of hospital stay, hemoglobin levels were significantly lower in both the older age group and the group with longer hospital stays. Conclusions: Serum levels of albumin, Hb, iron, and zinc were very low in most diabetic foot patients. These low values may have a negative relationship with wound healing. Nutrient replacements are necessary for wound healing in diabetic foot patients.

Initial handgrip strength as a predictive factor for amputation risk in diabetic foot patients.

BACKGROUND: We aimed to analyze the prognostic significance of handgrip strength as predictor of lower extremity amputation at 1 year follow up in patients with type 2 diabetes. METHODS: We evaluated 526 patients with type 2 diabetes between August 2020, and, June 2022. We collected from the electronic medical records demographic variables, laboratory data and history of amputation. The handgrip strength was assessed using a handheld Smedley digital dynamometer following the NHANES Muscle Strenght/Grip Test Procedure. Low handgrip strength was defined for women as less than 16 kg and for men less than 27 kg. Outcome variable was major or minor lower extremity amputation. RESULTS: A total of 205 patients with complete data entered the study. Patients mean age was 59 years old, 37% were women and the mean diabetes disease duration was 14 years. Seventy-seven (37%) patients suffered from lower extremity mputations (26 major and 51 minor amputations). After controlling for age, gender, presence of peripheral artery disease, body mass index and white cell counts as confounder variables, patients with low handgrip had an increased risk for amputations (Odds Ratio 2.17; 95% confidence Interval: 1.09-4.32; <0.001). CONCLUSION: Low handgrip stregth is an independent prognostic marker for lower limb amputation at one year in patients with diabetes.

The Stress of Measuring Plantar Tissue Stress in People with Diabetes-Related Foot Ulcers: Biomechanical and Feasibility Findings from Two Prospective Cohort Studies.

Reducing high mechanical stress is imperative to heal diabetes-related foot ulcers. We explored the association of cumulative plantar tissue stress (CPTS) and plantar foot ulcer healing, and the feasibility of measuring CPTS, in two prospective cohort studies (Australia (AU) and The Netherlands (NL)). Both studies used multiple sensors to measure factors to determine CPTS: plantar pressures, weight-bearing activities, and adherence to offloading treatments, with thermal stress response also measured to estimate shear stress in the AU-study. The primary outcome was ulcer healing at 12 weeks. Twenty-five participants were recruited: 13 in the AU-study and 12 in the NL-study. CPTS data were complete for five participants (38%) at baseline and one (8%) during follow-up in the AU-study, and one (8%) at baseline and zero (0%) during follow-up in the NL-study. Reasons for low completion at baseline were technical issues (AU-study: 31%, NL-study: 50%), non-adherent participants (15% and 8%) or combinations (15% and 33%); and at follow-up refusal of participants (62% and 25%). These underpowered findings showed that CPTS was non-significantly lower in people who healed compared with non-healed people (457 [117; 727], 679 [312; 1327] MPa·s/day). Current feasibility of CPTS seems low, given technical challenges and non-adherence, which may reflect the burden of treating diabetes-related foot ulcers.

An observational study of the pH value during the healing process of diabetic foot ulcer.

OBJECTIVE: In this study, we evaluated the pH (potential of hydrogen) value of diabetic foot ulcers and explored the relationship between the pH value and infection, sinus formation, stasis dermatitis, and the process of healing. METHODS: From October 2022 to June 2023, 99 patients with 106 diabetic foot ulcers were selected. Diabetic foot ulcers were treated in a standardized manner by a professional team. The pH value, area, PUSH (Pressure Ulcer Scale for Healing) score, and the degree of infection of the wounds were compared before and after the treatment. RESULTS: The baseline wound pH value in 76.4% of the patients was in the alkaline range and was closely related to the degree of infection (P < 0.05). As the ulcers healed, the pH decreased. For moderately and severely infected diabetic foot ulcers, each unit decrease in pH was associated with a decrease in the PUSH score of approximately 4.6 points (P < 0.05). The pH values of wounds with surrounding ecchymosis dermatitis were significantly higher than those of wounds without ecchymosis dermatitis (P < 0.05). The pH value of the wound with a sinus tract was higher. After treatment, there was no significant difference in pH value between the patients with and without sinus tracts (P < 0.05). CONCLUSIONS: The measurement of pH value is efficient and simple, and the patient suffers no discomfort in the process. The change in pH helps predict the healing process of diabetic foot ulcers and quickly identify whether there are key factors such as infection and ischemia in the wound. It is suggested that dynamic pH monitoring be included in the whole course evaluation and intervention strategy development of diabetic foot.

Proximal Arterial Inflow Revascularization Improves Pedal Arch Quality and Its Impact on Ischemic Diabetic Foot Ulcer Healing.

BACKGROUND: Arterial perfusion is a key factor in diabetic foot ulcer (DFU) healing. Although it is associated with pedal arch patency, not all patients are amenable to pedal artery angioplasty. This study aims to determine the impact of angiographic improvement of the pedal arch quality after proximal arterial inflow revascularization (PAIR) and its association with wound healing. METHODS: One hundred and fifty diabetic patients with tissue loss in 163 limbs who had digital subtraction angiography were studied. Cox regression analysis was used to determine independent predictors of wound healing. Wound healing rates in association with pedal arch patency were calculated by Kaplan-Meier analysis. RESULTS: End-stage renal disease, minor amputation, and complete pedal arch patency were significant independent predictors of wound healing following PAIR with hazard ratios for failure: 3.02 (P = 0.008), 0.54 (P = 0.023), and 0.40 (P = 0.039), respectively. The prevalence of complete pedal arches increased by 24.1% with successful intervention (P < 0.001). The overall rates of wound healing at 6, 12, and 24 months were 36%, 64%, and 72%, respectively. The wound healing rate at 1 year in patients with a complete pedal arch was 73% compared to 45% in those with an absent pedal arch (P = 0.017). CONCLUSIONS: PAIR increases complete pedal arch patency, a significant predictor of wound healing in DFU.

What Are Diabetic Foot Ulcers?

This JAMA Patient Page describes diabetic foot ulcers and their evaluation and treatment.

Microenvironment-Based Diabetic Foot Ulcer Nanomedicine.

Diabetic foot ulcers (DFU), one of the most serious complications of diabetes, are essentially chronic, nonhealing wounds caused by diabetic neuropathy, vascular disease, and bacterial infection. Given its pathogenesis, the DFU microenvironment is rather complicated and characterized by hyperglycemia, ischemia, hypoxia, hyperinflammation, and persistent infection. However, the current clinical therapies for DFU are dissatisfactory, which drives researchers to turn attention to advanced nanotechnology to address DFU therapeutic bottlenecks. In the last decade, a large number of multifunctional nanosystems based on the microenvironment of DFU have been developed with positive effects in DFU therapy, forming a novel concept of "DFU nanomedicine". However, a systematic overview of DFU nanomedicine is still unavailable in the literature. This review summarizes the microenvironmental characteristics of DFU, presents the main progress of wound healing, and summaries the state-of-the-art therapeutic strategies for DFU. Furthermore, the main challenges and future perspectives in this field are discussed and prospected, aiming to fuel and foster the development of DFU nanomedicines successfully.

Terahertz imaging demonstrates its diagnostic potential and reveals a relationship between cutaneous dehydration and neuropathy for diabetic foot syndrome patients.

Diabetic foot syndrome, a long term consequence of Diabetes Mellitus, is the most common cause of non-traumatic amputations. Around 8% of the world population suffers from diabetes, 15% of diabetic patients present a diabetic foot ulcer which leads to amputation in 2.5% of the cases. There is no objective method for the early diagnosis and prevention of the syndrome and its consequences. We test terahertz imaging, which is capable of mapping the cutaneous hydration, for the evaluation of the diabetic foot deterioration as an early diagnostic test as well as ulcers prevention and tracking tool. Furthermore, the analysis of our terahertz measurements combined with neurological and vascular assessment of the patients indicates that the dehydration is mainly related to the peripheral neuropathy without a significant vascular cause.

Worldwide Research Trends on Diabetic Foot Ulcers (2004-2020): Suggestions for Researchers.

OBJECTIVES: Diabetic foot ulcer (DFU) is one of the devastating complications of diabetes. It has high mortality and disability rates. The number of research articles on DFUs has increased. This study was designed to explore the global trends and research hotspots of DFUs to benefit researchers in shaping future research directions. METHODS: Literatures relating to DFU from 2004 to 2020 were retrieved from the Science Citation Index Expanded (SCI-expanded) of Web of Science Core Collection (WoSCC). The current status of DFU research (including publications, journals, the performances of relevant countries, institutions, and authors and the research trends and hotspots of DFU) was analyzed with the WoSCC. VOSviewer v1.6.10.0 was utilised for cocitation, coauthorship, cooccurrence analyses, and bibliographic coupling. RESULTS: A total of 5869 publications on DFUs were retrieved. We performed a longitudinal review of publications over 17 years: 4500 articles and 865 review articles on DFUs published from 2004 to 2020 were analyzed. The total citation was 107,296. The USA (n = 1866), England (n = 606), and China (n = 599) were the three largest contributors. The University of Washington had the greatest number of publications within this time period (n = 103), and it had the most cooperative units and was in the core position in all research institutions, followed by the University of Manchester (n = 94) and the University of Miami (n = 92). Armstrong DG (91/1.69%) and Lavery LA (55/1.19%) should be regarded as scholars who have made outstanding contributions. The top journal with the greatest total link strength was Diabetes Care. Analysis showed that the global research hotspots of DFU focused on lower limb amputation, diabetic foot infection, and treatment and management of DFU. Studies on osteomyelitis, wound therapy and management, multidisciplinary integration and mechanism of DFUs, and its related diseases are the research fronts that should be closely watched in the future. CONCLUSIONS: This study revealed the current research status and hotspots in the domain of DFU over the past 17 years, which can help researchers to further pinpoint potential perspectives on hot topics and research frontiers.