The association of diabetic microvascular and macrovascular disease with cutaneous circulation in patients with type 2 diabetes mellitus

The role of FGF-21 in promoting diabetic wound healing by modulating high glucose-induced inflammation

Background

Wound healing is a complex biological process that can be impaired in individuals with diabetes. Diabetic wounds are a serious complication of diabetes that require promoting diagnosis and effective treatment. FGF-21, a member of the endocrine FGF factors family, has caught the spotlight in the treatment of diabetes for its beneficial effects on accelerating human glucose uptake and fat catabolism. However, the therapeutic efficacy of FGF-21 in promoting diabetic wounds remains unknown. This study aims to evaluate the therapeutic potential of FGF-21 in promoting diabetic wound healing.

Methods

we investigated the effects of FGF-21 on wound healing related-cells under high-glucose conditions using various assays such as CCK8, scratch assay, flow cytometry analysis, endothelial tube-formation assay, and transmission electron microscopy. Furthermore, we used db/db mice to verify the healing-promoting therapeutic effects of FGF-21 on diabetic wounds. We also conducted qRT-PCR, Western blot, and immunofluorescence staining analyses to elucidate the underlying mechanism.

Result

Our results indicate that FGF-21 treatment restored hyperglycemic damage on endothelial cell proliferation, migration, and tube-forming ability. It also reduced endothelial cell death rates under high-glucose conditions. TEM analysis showed that FGF-21 treatment effectively restored mitochondrial damage and morphological changes in endothelial cells caused by glucose. Additionally, qRT-PCR and Western blot analysis indicated that FGF-21 treatment restored inflammatory responses caused by hyperglycemic damage. Animal experiments confirmed these findings, suggesting that FGF-21 may be a promising candidate for the treatment of non-healing diabetic wounds due to its effectiveness in stimulating angiogenesis and anti-inflammatory function.

Conclusion

Our study provides evidence that FGF-21 is an essential regulator of wound-related cells under high-glucose conditions and has the potential to be a novel therapeutic target for accelerating diabetic wound healing.

Molecular mechanism and intervention measures of microvascular complications in diabetes

Objective

In this article, the epidemiology, molecular mechanism of occurrence and development, risk factors, and treatment of diabetic microvascular complications such as diabetic nephropathy, diabetic retinopathy, and diabetic peripheral neuropathy were discussed, providing the theoretical basis for more accurate elucidation of the pathogenesis and treatment of diabetic microvascular complications.

Methods

The electronic database of PubMed was searched, and retrieved papers were screened for eligibility by two independent reviewers. Data were extracted using a standardized data extraction form and the quality of included papers was assessed.

Results

Thirty-eight articles were included. Diabetes nephropathy, diabetes peripheral neuropathy, and diabetes retinopathy are the most common and serious microvascular complications of diabetes in clinical patients. Renin-angiotensin system blockers, beta drugs, statins, antivascular endothelial growth factor drugs, and antioxidants can inhibit the occurrence of microvascular complications in diabetes.

Conclusions

However, there has been no breakthrough in the treatment of diabetic microvascular complications. Therefore, prevention of diabetic microvascular complications is more important than treatment.

Mikrozirkulationsstörungen der Haut: Microcirculation disorders of the skin

Veränderungen in der Mikrozirkulation der Haut sind ein häufig beobachtetes Begleitphänomen vieler Erkrankungen, weit über das Spektrum dermatologischer Krankheiten hinausreichend. Nicht alle dieser Veränderungen haben einen Krankheitswert, viele treten temporär auf, ohne schwerwiegende Folgen zu verursachen. Dies trifft für viele inflammatorische Erkrankungen wie die Psoriasis vulgaris oder das atopische Ekzem zu.

Daneben gibt es aber auch Erkrankungen, bei denen funktionell und morphologisch erkennbare Mikroangiopathien zu schwerwiegenden Krankheitsfolgen führen. Eine der wichtigsten Erkrankungen in diesem Zusammenhang ist die systemische Sklerose, eine autoimmune Systemerkrankung mit multiplen Organmanifestationen. Hier sind die Untersuchungen der kutanen Mikrozirkulation sowohl in der Erstdiagnose als auch in der Prognose‐ und Verlaufsbeurteilung von weitreichender Bedeutung.

Auch bei Erkrankungen der peripheren Hämodynamik wie der peripheren arteriellen Verschlusskrankheit (pAVK) und der chronisch venösen Insuffizienz (CVI) spielt das Verständnis von Mikrozirkulationsstörungen eine wichtige Rolle für die Therapie und die Erfolgskontrolle therapeutischer Interventionen.

Microcirculation disorders of the skin

Changes in the microcirculation of the skin are a frequently observed accompanying phenomenon of many diseases, far beyond the spectrum of dermatological diseases. Not all of these changes are pathological, many are transient and have no serious consequences. This is true for many inflammatory diseases such as psoriasis vulgaris or atopic eczema. However, there are also diseases in which functionally and morphologically recognizable microangiopathies lead to severe disease consequences. One of the most important diseases in this context is systemic sclerosis, an autoimmune systemic disease with multiple organ manifestations. Investigations of the cutaneous microcirculation are of great importance for the initial diagnosis as well as for prognosis and assessment of disease progression. In peripheral hemodynamic disorders such as peripheral arterial disease (PAD) and chronic venous insufficiency (CVI), understanding microcirculatory disturbances also plays an important role in therapy and in monitoring the success of therapeutic interventions.

Use of consecutive transcutaneous oxygen measurement when assessing the need for revascularization and association with the outcomes of ischemic diabetic ulcers

This study compared the ankle-brachial index (ABI) with transcutaneous oxygen pressure (TcPO2 ) in assessing peripheral vascular disease (PVD) prevalence in 100 diabetic foot ulcer (DFU) patients. Patients were categorized into vascular or nonvascular reconstruction groups and underwent both ABI and TcPO2 measurements four times over 6 months. Predictive validity for PVD diagnosis was analysed using the area under the receiver-operating characteristic curve (AUC). The study found TcPO2 to be a superior predictor of PVD than ABI. Among the DFU patients, 51 with abnormal TcPO2 values underwent vascular reconstruction. Only TcPO2 values showed significant pretreatment differences between the groups and increased post-reconstruction. These values declined over a 6-month follow-up, whereas ABI values rose. For those with end-stage renal disease (ESRD), TcPO2 values saw a sharp decrease within 3 months. Pre-reconstruction TcPO2 was notably lower in amputation patients versus limb salvage surgery patients. In conclusion, TcPO2 is more effective than ABI for evaluating ischemic limb perfusion and revascularization necessity. It should be prioritized as the primary follow-up tool, especially for ESRD patients.

Correlation of leg pain responses with ankle-brachial index and peripheral sensory responses in foot of type 2 diabetes mellitus

Introduction: Type 2 Diabetes Mellitus (T2DM) is associated with changes that occur in the peripheral circulation that affect foot functions. Therefore, there is a need for a risk prediction test on foot abnormalities using the leg pain response parameters in T2DM patients with ankle-brachial index (ABI) and peripheral sensory changes as a preventive effort to manage foot care. Design and Methods: This study employed a cross-sectional design in which 63 T2DM patients in a Public Health Center (PHC) in Malang were investigated. The instruments used include visual analog scale (VAS), monofilament, and foot doppler. Results: The Pearson correlation test showed no relationship between the responses to leg pain and the ABI of the right and left feet (p-values = 0.217 and 0.692), but there was a significant relationship between the left foot ABI and sensory status (p-value 0.002; left foot r = 0.383). Meanwhile, the Pearson's correlation and linear regression test also showed a relationship between the right foot ABI and sensory status (p-value = 0.007; r = 0.338). Furthermore, a multiple linear regression test showed a relationship between the leg pain response and sensory perception of the right and left feet (p-value = 0.035; r = 0.325). Conclusions: The relationship between the sensory status of the right and left feet and the response to leg pain in T2DM patients were moderate with a negative direction. It, therefore, implies that a decrease in the sensory responses increased the leg pain. Meanwhile, the moderate relationship and positive direction between the ABI and sensory status of the feet of T2DM patients indicates that a higher ABI score led to an increase in the sensory status of the foot.

Microcirculation Improvement in Diabetic Foot Patients after Treatment with Sucrose Octasulfate-Impregnated Dressings

To assess the patients' microcirculation evolution during the treatment with a sucrose octasulfate-impregnated dressing, fifty patients with neuroischaemic DFU treated with TLC-NOSF dressing were included in a prospective study between November 2020 and February 2022. TcpO₂ values were measured on the dorsalis pedis or tibial posterior arteries' angiosome according to the ulcer location. TcpO₂ values were assessed at day 0 and every 4 weeks during 20 weeks of the follow-up or until the wound healed. A cut-off point of tcpO₂ < 30 mmHg was defined for patients with impaired microcirculation. The TcpO₂ values showed an increase between day 0 and the end of the study, 33.04 ± 12.27 mmHg and 40.89 ± 13.06 mmHg, respectively, p < 0.001. Patients with impaired microcirculation showed an increase in the tcpO₂ values from day 0 to the end of the study (p = 0.023). Furthermore, we observed a significant increase in the TcpO₂ values in the forefoot DFU (p = 0.002) and in the rearfoot DFU (p = 0.071), with no difference between the ulcer locations (p = 0.694). The local treatment with TLC-NOSF dressing improved the microcirculation in patients with neuroischaemic DFU, regardless of microcirculation status at the baseline, and in the forefoot, regardless of the location.

Nomogram Prediction for the Risk of Diabetic Foot in Patients With Type 2 Diabetes Mellitus

AIMS

To develop and validate a nomogram prediction model for the risk of diabetic foot in patients with type 2 diabetes mellitus (T2DM) and evaluate its clinical application value.

METHODS

We retrospectively collected clinical data from 1,950 patients with T2DM from the Second Affiliated Hospital of Xi'an Jiaotong University between January 2012 and June 2021. The patients were divided into training cohort and validation cohort according to the random number table method at a ratio of 7:3. The independent risk factors for diabetic foot among patients with T2DM were identified by multivariate logistic regression analysis. Then, a nomogram prediction model was developed using the independent risk factors. The model performances were evaluated by the area under the receiver operating characteristic curve (AUC), calibration plot, Hosmer-Lemeshow test, and the decision curve analysis (DCA).

RESULTS

Multivariate logistic regression analysis indicated that age, hemoglobin A1c (HbA1c), low-density lipoprotein (LDL), total cholesterol (TC), smoke, and drink were independent risk factors for diabetic foot among patients with T2DM (P < 0.05). The AUCs of training cohort and validation cohort were 0.806 (95% CI: 0.775∼0.837) and 0.857 (95% CI: 0.814∼0.899), respectively, suggesting good discrimination of the model. Calibration curves of training cohort and validation cohort showed a favorable consistency between the predicted probability and the actual probability. In addition, the P values of Hosmer-Lemeshow test for training cohort and validation cohort were 0.826 and 0.480, respectively, suggesting a high calibration of the model. When the threshold probability was set as 11.6% in the DCA curve, the clinical net benefits of training cohort and validation cohort were 58% and 65%, respectively, indicating good clinical usefulness of the model.

CONCLUSION

We developed and validated a user-friendly nomogram prediction model for the risk of diabetic foot in patients with T2DM. Nomograms may help clinicians early screen and identify patients at high risk of diabetic foot.

Effect of whole-body vibration training on transcutaneous oxygen levels of the foot in patients with type 2 diabetes: A randomized controlled trial

Whole body vibration (WBV) has been suggested as improving skin and blood flow. This study aimed to determine the effect of exposure to WBV on levels of partial transcutaneous oxygen pressure (TcPO2) in the foot of patients with type 2 diabetes (T2D) within the metabolic control goals. A block randomized, open, two-arm, parallel and controlled clinical trial was conducted. Participants recruited from the Center of Comprehensive Care for the Patient with Diabetes were assessed at the National Institute of Rehabilitation, Mexico City. Control group underwent multidisciplinary care for T2D; experimental group, in addition to the comprehensive diabetes care, was exposed to WBV through an exercise program, attending three times a week for a period of 3 months. TcPO2 was measured in the feet of the participants at baseline and after 12 weeks. A sample of 50 volunteers with recently-diagnosed T2D and similar baseline characteristics (demographic, cardiovascular risk, presence of diabetic polyneuropathy, and indicators of glycemic control and TcPO2) was recruited. The experimental group (n = 27) showed a mean value of 47.7 ± 6.1 mmHg in TcPO2, significantly higher (p = 0.028) than the 44.3 ± 7.5 mmHg of control group (n = 23), at the end of intervention. In conclusion, exposure to WBV promoted an increase and a significant 3 mmHg difference in the foot TcPO2 levels between those subjects with T2D that underwent the 12-week exercise program and those not exposed to the treatment.

Impaired dermal microvascular reactivity and implications for diabetic wound formation and healing: an evidence review

Diabetic foot ulcers (DFUs) are among the most consequential and costly complications faced by patients with diabetes and the global healthcare system. Acknowledged risk factors for DFUs include diabetic peripheral neuropathy (DPN), peripheral arterial disease (PAD), microtrauma and foot deformities. Research on additional risk factors for DFUs has recently focused on dysregulated, autonomic vasomotor control in the skin of patients with DPN. In particular, impaired dermal microvascular reactivity (IDMR) with its attendant reduction in nutritive capillary blood flow has been identified as an emerging risk factor. This especially relates to refractory wounds noted in patients without overt PAD signs. In this paper, evidence will be reviewed supporting the evolving understanding of IDMR and its impact on DFU formation and healing. Advances in diagnostic instrumentation driving this research along with the most promising potential therapies aimed at improving microvascular function in the diabetic foot will be discussed in brief.

CDATA[The Effect of Oxidative Stress and Antioxidant Therapies on Pancreatic β-cell Dysfunction: Results from in Vitro and in Vivo Studies

BACKGROUND

Oxidative stress is a hallmark of many diseases. A growing body of evidence suggests that hyperglycemia-induced oxidative stress plays an important role in pancreatic β-cells dysfunction and apoptosis, as well as in the development and progression of diabetic complications. Considering the vulnerability of pancreatic β-cells to oxidative damage, the induction of endogenous antioxidant enzymes or exogenous antioxidant administration has been proposed to protect pancreatic β-cells from damage.

OBJECTIVES

The present review aims to provide evidence of the effect of oxidative stress and antioxidant therapies on pancreatic β-cell function, based on in vitro and in vivo studies.

METHODS

The MEDLINE and EMBASE databases were searched to retrieve available data.

RESULTS

Due to poor endogenous antioxidant mechanisms, pancreatic β-cells are extremely sensitive to Reactive Oxygen Species (ROS). Many natural extracts have been tested in vitro in pancreatic β-cell lines in terms of their antioxidant and diabetes mellitus ameliorating effects, and the majority of them have shown a dose-dependent protective role. On the other hand, there is relatively limited evidence regarding the in vitro antioxidant effects of antidiabetic drugs on pancreatic β -cells. Concerning in vivo studies, several natural extracts have shown beneficial effects in the setting of diabetes by decreasing blood glucose and lipid levels, increasing insulin sensitivity, and by up-regulating intrinsic antioxidant enzyme activity. However, there is limited evidence obtained from in vivo studies regarding antidiabetic drugs.

CONCLUSION

Antioxidants hold promise for developing strategies aimed at the prevention or treatment of diabetes mellitus associated with pancreatic β-cells dysfunction, as supported by in vitro and in vivo studies. However, more in vitro studies are required for drugs.

Impairment of microvascular blood flow in patients with type 2 diabetes and cardiovascular autonomic neuropathy

BACKGROUND: Diabetic autonomic neuropathy is the reason for early morbidity and mortality on diabetic patients. The pathology not only cardiac innervation but microvascular is presented.

AIMS: We estimated the parameters of skin microvascular blood flow in accordance with cardiovascular autonomic neuropathy (CAN) staging in diabetic patients. We also assessed other risk factors of CAN in patients with diabetes.

MATERIALS AND METHODS: We included 76 patients with type 2 diabetes in the study (24 patients with resent-onset diabetes and/or diabetes without microvascular complications, 26 with diabetic sensorimotor neuropathy (SMN) and 26 with SMN and previous history of diabetic foot amputation). The SMN was diagnosed on the basis of patients complaints, anamnesis and data of clinical neurological examinations. CAN was detected using several cardiovascular autonomic reflex tests (CART) as a gold standard of diagnosis: the tilt-table test, a deepbreathing and Valsalva Maneuver, handgrip test, cold-stress vasoconstriction. According to the Toronto Diabetic Neuropathy Expert Group Recommendation all patients was separated on the groups: CAN 0 (all CARTs were normal), CAN 1 (possible/early CAN — one abnormal CART was presented), CAN 2 (definite/confirmed CAN –at least two abnormal CARTs were found), CAN 3 (severe/advanced CAN — in the cases of orthostatic hypotension in addition to CARTs abnormalities). Microvascular blood flow of skin at the nail roller of fingers skin was valuated at rest as well as in functional cold test by the method of High-frequency Ultrasonic Dopplerography using the “Minimax Doppler K” device (LLC JV “Minimax”, St. Petersburg, Russia).

RESULTS: CAN 1 was found in 8% diabetic patients without microvascular complications, 42 and 21% patients with SMN and diabetic foot amputations respectively. CAN 2 was diagnosed in 27% patients with SMN and 58% patients history of diabetic foot amputations. CAN 3 in 8% and 19% cases in patients with SMN and history of diabetic foot amputations respectively. The parameters of microvascular blood flow at rest were significantly decreased in patients with confirmed/severe CAN in comparison with early staging of CAN and patients without CAN (Vm=2.5±0.66 sm/sec vs. 4.4±0.54 sm/sec and 5.1±1.01 sm/sec respectively; p=0.0033). The abnormal result of cold test was detected in 94% patients with confirmed/ severe CAN and 26% patients with CAN 1.

CONCLUSIONS: This investigation has demonstrated in a cohort with type 2 diabetes patients with/without SMN and with/ without history of previously foot amputations that decrease the Vm (the variable of microvascular blood flow assessed by High-frequency Ultrasonic Dopplerography) lower than 2.4 sm/sec is associated with 6.4 times increased likelihood of confirmed/severe CAN as well as positive cold test result. That the patients with positive cold test results were 28.6 times more likely have confirmed/severe CAN.

Diabetes Attenuates the Contribution of Endogenous Nitric Oxide but Not Nitroxyl to Endothelium Dependent Relaxation of Rat Carotid Arteries

Endothelial dysfunction is a major risk factor for several of the vascular complications of diabetes, including ischemic stroke. Nitroxyl (HNO), the one electron reduced and protonated form of nitric oxide (NO•), is resistant to scavenging by superoxide, but the role of HNO in diabetes mellitus associated endothelial dysfunction in the carotid artery remains unknown. Aim: To assess how diabetes affects the role of endogenous NO• and HNO in endothelium-dependent relaxation in rat isolated carotid arteries. Methods: Male Sprague Dawley rats were fed a high-fat-diet (HFD) for 2 weeks prior to administration of low dose streptozotocin (STZ; 35 mg/kg i. p./day) for 2 days. The HFD was continued for a further 12 weeks. Sham rats were fed standard chow and administered with citrate vehicle. After 14 weeks total, rats were anesthetized and carotid arteries collected to assess responses to the endothelium-dependent vasodilator, acetylcholine (ACh) by myography. The combination of calcium-activated potassium channel blockers, TRAM-34 (1 μmol/L) and apamin (1 μmol/L) was used to assess the contribution of endothelium-dependent hyperpolarization to relaxation. The corresponding contribution of NOS-derived nitrogen oxide species to relaxation was assessed using the combination of the NO• synthase inhibitor, L-NAME (200 μmol/L) and the soluble guanylate cyclase inhibitor ODQ (10 μmol/L). Lastly, L-cysteine (3 mmol/L), a selective HNO scavenger, and hydroxocobalamin (HXC; 100 μmol/L), a NO• scavenger, were used to distinguish between NO• and HNO-mediated relaxation. Results: At study end, diabetic rats exhibited significantly retarded body weight gain and elevated blood glucose levels compared to sham rats. The sensitivity and the maximal relaxation response to ACh was significantly impaired in carotid arteries from diabetic rats, indicating endothelial dysfunction. The vasorelaxation evoked by ACh was abolished by L-NAME plus ODQ, but not affected by the apamin plus TRAM-34 combination, indicating that NOS-derived nitrogen oxide species are the predominant endothelium-derived vasodilators in sham and diabetic rat carotid arteries. The maximum relaxation to ACh was significantly decreased by L-cysteine in both sham and diabetic rats, whereas HXC attenuated ACh-induced relaxation only in sham rats, suggesting that diabetes impaired the contribution of NO•, whereas HNO-mediated vasorelaxation remained intact. Conclusion: Both NO• and HNO contribute to endothelium-dependent relaxation in carotid arteries. In diabetes, NO•-mediated relaxation is impaired, whereas HNO-mediated relaxation was preserved. The potential for preserved HNO activity under pathological conditions that are associated with oxidative stress indicates that HNO donors may represent a viable therapeutic approach to the treatment of vascular dysfunction.

Mechanistic Actions of microRNAs in Diabetic Wound Healing

Wound healing is a complex biological process that is impaired under diabetes conditions. Chronic non-healing wounds in diabetes are some of the most expensive healthcare expenditures worldwide. Early diagnosis and efficacious treatment strategies are needed. microRNAs (miRNAs), a class of 18–25 nucleotide long RNAs, are important regulatory molecules involved in gene expression regulation and in the repression of translation, controlling protein expression in health and disease. Recently, miRNAs have emerged as critical players in impaired wound healing and could be targets for potential therapies for non-healing wounds. Here, we review and discuss the mechanistic background of miRNA actions in chronic wounds that can shed the light on their utilization as specific wound healing biomarkers.

Factors associated with sclerostin levels - A calcification inhibitor - In individuals with type 2 diabetes mellitus; Is autonomic neuropathy the missing link?

BACKGROUND

Sclerostin inhibits bone formation and its expression is upregulated in the vasculature during the arterial calcification process as a counterregulatory mechanism preventing further calcification. Lower extremity arterial calcification (LEAC) is common in neuropathic patients with type 2 diabetes (T2DM). Herein, we investigated for associations between plasma sclerostin levels and diabetic neuropathy as well as LEAC in subjects with T2DM.

METHODS

A total of 74 individuals with and 76 without T2DMwere recruited. Plasma sclerostin levels were measured by ELISA. Diagnosis of cardiac autonomic neuropathy (CAN) was based on the battery of the four autonomic tests, while of somatosensory peripheral neuropathy (DPN) on neuropathy symptom score and neuropathy disability score. LEAC was assessed with conventional ankle and foot x-rays.

RESULTS

Plasma sclerostin levels were higher in participants with LEAC vs. those without LEAC in both diabetes and non-diabetes cohorts (p = 0.035 and p = 0.003, respectively). In the diabetes cohort, patients with CAN, but not with DPN, had higher sclerostin levels when compared with those without CAN (p < 0.001). Multivariate analysis in the diabetes cohort demonstrated that sclerostin levels were associated positively with CAN and LEAC, while in the non-diabetes cohort there was a trend for a positive association with male gender and presence of LEAC.

CONCLUSION

Plasma sclerostin levels are increased in individuals with LEAC irrespectively of diabetes status. In addition, plasma sclerostin concentrations are associated independently with LEAC and CAN in people with T2DM.

Chronic Diabetes Complications: The Need to Move beyond Classical Concepts

Chronic-diabetes-related complications simultaneously compromise both the micro- and macrovascular trees, with target organs considered as the paradigm of large vessel injury also entailing microangiopathic changes. However, complications independent or partially independent from vascular damage are often overlooked. This includes neuronal dysfunction (e.g., retinal neurodegeneration), interstitial injury (e.g., tubulointerstitial disease), metabolic damage (e.g., in the heart and liver), and nonclassical conditions such as cognitive decline, impaired pulmonary function, or increased risk of cancer. In this scenario, researchers, endocrinologists and primary care physicians should have a holistic view of the disease and pay further attention to all organs and all potential clinical repercussions, which would certainly contribute to a more rational and integrated patient health care.

Dryness of Foot Skin Assessed by the Visual Indicator Test and Risk of Diabetic Foot Ulceration: A Prospective Observational Study

Research Question: Previous cross-sectional studies have shown an association between sudomotor dysfunction and diabetic foot ulceration (DFU). The aim of this prospective multicenter study was to determine the role of dryness of foot skin and of established neurological modalities in the prediction of risk for foot ulceration in a cohort of individuals with diabetes mellitus (DM). Design: The study was conducted from 2012 to 2017. A total of 308 subjects with DM without history of DFU or critical limb ischemia completed the study. Diabetic neuropathy was assessed using the neuropathy symptom score (NSS) and neuropathy disability score (NDS). In a subset of participants, vibration perception threshold (VPT) was evaluated. Dryness of foot skin was assessed by the visual indicator plaster method (IPM). The diagnostic performance of the above neurological modalities for prediction of DFU was tested by receiver operating characteristic curve (ROC) analysis. Results: During the 6-year follow-up, 55 patients (annual ulceration incidence 2.97%) developed DFU. Multivariate Cox-regression analysis after controlling for the effect of age, gender, and DM duration demonstrated that the risk (hazard ratio, 95% confidence intervals) of DFU increased significantly with either abnormal IPM (3.319, 1.460-7.545, p = 0.004) or high (≥6) NDS (2.782, 1.546-5.007, p = 0.001) or high (≥25 volts) VPT (2.587, 1.277-5.242, p = 0.008). ROC analysis showed that all neurological modalities could discriminate participants who developed DFU (p < 0.001). IPM testing showed high sensitivity (0.86) and low specificity (0.49), while high vs. low NDS and VPT showed low sensitivity (0.40 and 0.39, respectively) and high specificity (0.87 and 0.89, respectively) for identification of patients at risk for DFU. Conclusion: Dryness of foot skin assessed by the IPM predicts the development of DFU. IPM testing has high sensitivity, whereas high NDS and VPT have high specificity in identifying subjects at risk for DFU. The IPM can be included in the screening methods for identification of the foot at risk.

Possibility of Injecting Adipose-Derived Stromal Vascular Fraction Cells to Accelerate Microcirculation in Ischemic Diabetic Feet: A Pilot Study

Background and Objectives

Beneficial effects of human adipose-derived stromal vascular fraction (SVF) cell injection on microcirculation have been recently reported in in vitro and in vivo studies. However, no clinical studies have reported its effect in diabetic patients who commonly experience compromised tissue perfusion, regardless of the status of intravascular blood flow. The present piloting study was designed to clinically examine the possibility of SVF cell injection to accelerate microcirculation, particularly in ischemic diabetic feet.

Methods

Ten diabetic feet were included to receive subcutaneous injection of SVF cells around wounds. Transcutaneous partial oxygen pressure (TcPO₂) and cutaneous microvascular blood flow were measured before and every four weeks after cell injection until the 12^th week visit.

Results

TcPO₂ values increased from 31.3±7.4 before injection to 46.4±8.2 mmHg at 12 weeks after SVF injection (1.5-fold, p<0.05). Cutaneous microvascular blood flow levels increased from 34.0±21.1 before injection to 76.1±32.5 perfusion unit at 12 weeks after SVF injection (2.2-fold, p<0.05). There were no adverse events related to SVF cell injection.

Conclusions

Results of this study demonstrate that adipose-derived SVF cell injection have the possibility to provide beneficial effects on microcirculation in ischemic diabetic feet.