Prediction of incident diabetic neuropathy using the monofilament examination: a 4-year prospective study

Exploration of predictive risk factors for diabetic foot in patients with diabetes in Beijing: analysis of 5-year follow-up data of patients with diabetes mellitus in a single center in Beijing

Background

Large-scale prospective cohort studies on diabetic foot ulcers risk factor screening in China are limited. Therefore, this prospective cohort study aimed to explore the predictive risk factors for diabetic foot ulcers to provide clinicians with concise and effective clinical indicators for identifying a high-risk diabetic foot and guiding the prevention of diabetic foot ulcers.

Methods

Patients with diabetes who visited the Department of Endocrinology of Peking University First Hospital from October 2017 to December 2018 were selected as research participants by convenience sampling. A total of 968 patients were included. After enrollment, a dedicated person collected and recorded all baseline data. A dedicated telephone follow-up was conducted every 12-24 months to evaluate whether the endpoint event had occurred. All patients were followed up for an average of 61 (57-71) months, with 95% of them followed up for more than 60 months. According to the occurrence of endpoint events, they were divided into the DFU and non-DFU groups. The data between the two groups were analyzed using independent-sample t-test, Wilcoxon rank sum test, and chi square test. We used univariate and multivariate logistic regression analysis to analyze the factors that affected the occurrence of diabetic foot ulcers.

Results and conclusions

After the 5-year follow-up, the incidence of diabetic foot was 25.83%. Multivariate logistic regression analysis revealed that body mass index (odds ratio: 1.046; 95% confidence interval: 1.001-1.093), abnormal pinprick sensation (odds ratio: 4.138; 95% confidence interval: 1.292-13.255), history of fungal foot infection (odds ratio: 2.287; 95% confidence interval: 1.517-3.448), abnormal 128-Hz tuning fork test (odds ratio: 2.628; 95% confidence interval: 1.098-6.294), and HbA1c≥ 8% (odds ratio: 1.522; 95% confidence interval: 1.014-2.284) were independent predictors of diabetic foot. Our study highlights clinically relevant indicators that may help to prevent the occurrence of diabetic foot and guide timely interventions.

Exploring the influence of dietary habits on foot risk in type 2 diabetes patients: An observational study

BACKGROUND & AIM

To date, there are no studies demonstrating the impact of the Mediterranean diet on the risk of diabetic foot ulcer. The aim of this research was to examine the connection between adherence to the Mediterranean diet and the level of risk of diabetic foot ulcers in individuals with type 2 diabetes.

METHODS

Observational pilot study collecting sociodemographic, anthropometric, lifestyle, and type 2 diabetes-related data. Loss of protective sensation was assessed using the Semmes Weinstein 5.07-10 g monofilament, considered altered when not perceived in four points. Vascular status was assessed by palpating pulses and ankle-brachial index, indicating peripheral arterial disease if ankle-brachial index was less than 0.9 or if both pulses were absent. Foot deformities were recorded. The risk of diabetic foot ulcers was stratified into two categories: no risk and risk of diabetic foot ulcers. Adherence to the Mediterranean diet was evaluated using the Mediterranean Diet Adherence Screener-14 questionnaire (good adherence with score >7).

RESULTS

Of the 174 patients with type 2 diabetes mellitus who participated (61.5% men and 38.5% women) with a mean age of 69.56 ± 8.86 years and a mean duration of type 2 diabetes of 15.34 ± 9.83 years. Non-adherent patients to the Mediterranean diet exhibited a higher association of diabetic foot ulcers (p = 0.030) and a lower average score on the Mediterranean Diet Adherence Screener-14 (p = 0.011). Additionally, a lower incidence of diabetic foot ulcers was observed in those who consumed nuts three or more times a week (p = 0.003) and sautéed foods two or more times a week (p = 0.003). Multivariate analysis highlighted the importance of physical activity (OR = 0.25, 95% CI 0.11-0.54; p < 0.001), podiatric treatment (OR = 2.59, 95% CI 1.21-5.56; p = 0.014), and duration of type 2 diabetes (OR = 3.25, 95% CI 1.76-5.99; p < 0.001) as significantly associated factors related to the risk of diabetic foot ulcers.

CONCLUSIONS

Adhering to the Mediterranean diet correlates with a lower incidence of diabetic foot ulcers in individuals diagnosed with type 2 diabetes mellitus. Furthermore, factors such as regular physical activity, podiatric treatment, and the duration of type 2 diabetes mellitus emerge as pivotal in preventing diabetic foot ulcers.

Relationship between diabetic peripheral neuropathy and adherence to the Mediterranean diet in patients with type 2 diabetes mellitus: an observational study

PURPOSE

The main study goal is to assess the relationship between adherence to the mediterranean diet (MD) and the presence of diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM).

METHODS

Observational pilot study of 174 patients diagnosed with T2DM. Sociodemographic and anthropometric variables, physical activity, smoking habits, blood biochemical parameters and comorbidities were recorded. The presence of alterations in sensitivity to pressure, pain, thermal and vibration was explored. Good MD adherence was a score  ≥  9 the 14-point MD adherence questionnaire (MEDAS-14).

RESULTS

The study population consisted of 174 patients (61.5% men and 38.5% women), with a mean age of 69.56 ± 8.86 years; 19% of these patients adhered to the MD. The score obtained in the MEDAS-14 was higher in patients who did not present alterations in sensitivity to pressure (p = 0.047) or vibration (p = 0.021). The patients without diabetic peripheral neuropathy were more likely to comply with the MD and had a higher score on the MEDAS-14 (p = 0.047). However, multivariate analysis showed that only altered sensitivity to pressure was associated with adherence to the MD (altered sensitivity OR = 2.9; 95%CI 1.02-8.22; p = 0.045).

CONCLUSIONS

Although the patients with DPN had lower scores on the MEDAS questionnaire and therefore poorer adherence to the mediterranean diet, the only parameter significantly associated with the MD was that of sensitivity to pressure (monofilament test).

A Review on Relationship Between Charcot Neuroarthropathy and Diabetic Patients

Charcot Neuroarthropathy (CN) is a complex and incapacitating disorder characterized by neuropathy, progressive deformity, and joint destruction. It is of substantial interest within the diabetic population as this ailment chiefly affects individuals with diabetes. The pathophysiology of CN is multidimensional, connecting peripheral neuropathy, repetitive trauma, and autonomic dysfunction. The review analyses the mechanisms directing the development of CN, emphasizing the influence of diabetes in individuals who lean toward this condition. Clinical presentation and diagnosis of CN in diabetic patients present unique challenges. Complex clinical features have also been discussed, including joint deformities, insidious onset, and painless swelling, which mimic other musculoskeletal conditions. The diagnostic approaches, involving clinical examination and radiological imaging, are analyzed for early and accurate diagnosis. Risk factors and epidemiology emphasize the prevalence of CN within the diabetic population and draw attention to common risk factors contributing to its development. Significant factors such as glycemic control, duration of the disease, and type of diabetes are important in estimating an individual's risk for CN. Complications, such as foot ulcers and amputations, provide an understanding of the severe outcome of this condition on patients' quality of life. Management approaches and treatment involving conservative and surgical approaches are reviewed in depth. A multidisciplinary approach to patient care is emphasized, given the complex nature of CN and the comorbidities existing in diabetic individuals. Prognosis and prevention comprise approaches for mitigating the risk of CN in diabetic patients, such as glycemic control, regular foot examinations, and patient education. This thorough review aims to outline the intricate relationship between CN and diabetes, offering an understanding of pathophysiology, clinical complexities, diagnostic nuances, treatment modalities, and prevention strategies.

The Composite Autonomic Symptom Score 31 Questionnaire: A Sensitive Test to Detect Risk for Autonomic Neuropathy

Background and Aims

Autonomic neuropathy is a common but often neglected complication of diabetes, prediabetes, and even in individuals with an elevated risk of diabetes. The Composite Autonomic Symptom Score (COMPASS) 31 is a validated and easy-to-use questionnaire regarding autonomic symptoms. We aimed to use a digitally, Norwegian version of the COMPASS 31 in people with different durations of diabetes and healthy controls to consider feasibility and to investigate if scores could discriminate between positive and negative outcomes for established tests for diabetic neuropathy, including cardiovascular autonomic neuropathy (CAN) and a novel method of examining the gastrointestinal visceral sensitivity.

Method

We included 21 participants with longstanding type 2 diabetes, 15 with early type 2 diabetes, and 30 matched controls. The mean age for all groups was 69 years. Participants were phenotyped by cardiovascular autonomic reflex tests, electrical skin conductance, sural nerve electrophysiology, and the monofilament test. As a proxy for gastrointestinal visceral and autonomic nerve function, evoked potentials were measured following rapid rectal balloon distention.

Results

Participants with longstanding diabetes scored a median (IQR) of 14.9 (10.8-28.7) points, early diabetes of 7.3 (1.6-15.2), and matched controls of 8.6 (4.1-21.6), p = 0.04. Women and men scored 14.4 (5.5-28.7) and 7.8 (3.6-14.6) points, respectively, p = 0.01. Participants with definite or borderline CAN scored 14.3 (10.4-31.9) points, compared to participants with no CAN, 8.3 (3.2-21.5), p = 0.04. Lowering the diagnostic cut-off from 16 to 10 points increased the sensitivity from 0.33 to 0.83, with a decreased specificity from 0.68 to 0.55.

Conclusion

We successfully used COMPASS 31 in Norwegian. Thus, following the guidelines, we suggest clinical implementation for the assessment of autonomic neuropathy. Participants with longstanding diabetes had an increased likelihood of symptoms and signs of autonomic neuropathy. For screening purposes, the sensitivity was improved by lowering the cut-off to 10 points, with a lower score nearly excluding the diagnosis.

The PanGut-study: Evoked potentials following rectal balloon distention, a way of evaluating diabetic autonomic neuropathy in the gut?

AIM

There is a lack of methods for investigating the autonomic nerves of the gastrointestinal tract. Our aim was to explore a novel test measuring visceral sensory evoked potentials (EPs) in response to rapid balloon distention in the rectum and compare it to established tests for diabetic neuropathy.

METHOD

Participants with longstanding type 2 diabetes, newly onset, untreated diabetes <1 year, and matched controls, were included. Tests included cardiovascular reflex tests, orthostatic blood pressure, electrical skin conductance assessment, sural nerve testing and monofilament test. The rectal balloon distention pressure at earliest sensation and threshold of unpleasantness were identified and used to elicit mechanical EPs.

RESULTS

The pressure at earliest sensation was higher in people with diabetes, 0.038 (0.012) bar vs. controls 0.030 (0.009) bar, p = 0.002, and in people with signs of peripheral neuropathy, 0.045 (0.014) bar, p < 0.01. Clinical correlations between EP amplitude and latency, and other tests were found.

CONCLUSIONS

Rectal hyposensitivity was associated with both longstanding and early diabetes, indicating enteric sensory dysfunction already in early stages of diabetes. Correlation analyses may indicate that central afferent processing is affected in parallel with peripheral neuronal function.

Diffusion-weighted MR imaging and utility of ADC measurements in characterizing nerve and muscle changes in diabetic patients on ankle DWI studies: a cross-sectional study

OBJECTIVE

To evaluate the utility of apparent diffusion coefficient (ADC) measurements from ankle MRI diffusion-weighted imaging (DWI) studies in identifying neuropathic changes in diabetic patients.

METHODS

In total, 109 consecutive ankle MRI scans (n = 101 patients) at a single tertiary care county hospital from November 1, 2019, to July 11, 2021, who met the inclusion criteria were identified. Patients were divided into 2 cohorts: diabetic (n = 62) and non-diabetic (n = 39). Demographics, HgbA1c, neuropathy diagnosis, and image quality data were collected. Abductor hallucis (AH) ADC mean and minimum (min) values and posterior tibial nerve (PTN) ADC mean and minimum values were measured. Student t-test and Pearson's correlation coefficient analysis were performed using R.

RESULTS

Diabetic patients had significantly higher mean and min ADC values (× 10^-3 mm²/s) of the AH muscle (mean: 1.77 vs 1.39, p < 0.001; min: 1.51 vs 1.06, p < 0.001) and PTN (mean: 1.65 vs 1.18, p < 0.001; min: 1.33 vs 0.95, p < 0.001) compared to non-diabetic patients. HgbA1c positively correlated with AH and PTN ADC mean values (AH: p = 0.036; PTN: p = 0.004).

CONCLUSION

Our data suggests that an increasing diffusivity of water as quantified by ADC across neuronal and muscular membranes is a consequence of the pathophysiology of the disease. Thus, ankle MRI-DWI studies are useful in identifying neuropathic changes in diabetic patients and quantifying the severity noninvasively.

KEY POINTS

• Diabetic patients had significantly higher mean and minimum ADC values of the abductor hallucis muscle and posterior tibial nerve compared to non-diabetic patients. • HgbA1c positively correlated with ADC mean values (AH: p = 0.036; PTN: p = 0.004) suggesting that an increasing diffusivity of water across neuronal and muscular membranes is a consequence of the pathophysiology of diabetic neuropathy. • Ankle MRI DWI can be used clinically to non-invasively identify neuropathic changes due to diabetes mellitus.

A Novel Classification for Diabetic Foot Ulcers of the First Ray

OBJECTIVE

Diabetic foot ulcers of the first ray result from several distinct biomechanical mechanisms related to anatomical deformities, which must be addressed if surgical offloading is contemplated. The objective of this study was to create a classification of the anatomical deformities of first-ray ulcers that could lead to better standardization of treatment and reporting.

METHODS

The authors performed a file review of patients with diabetic neuropathy diagnosed with first-ray ulcers over a period of 3 years in an outpatient setting. Anatomical deformities were diagnosed clinically and reported with ulcer location. The primary classification was the metatarsophalangeal joint, the interphalangeal joint, and the distal phalanx.

RESULTS

Records for 59 patients (mean age, 62 years) with University of Texas A1 and A2 ulcers were reviewed. Mean ulcer duration was 2 months. The more common deformities were hallux valgus (41%), hallux valgus interphalangeus (14%), and hallux malleus (20%), and these were primarily associated with metatarsophalangeal, interphalangeal joint, and tip-of-toe ulcers, respectively (P < .0001).

CONCLUSIONS

By classifying ulcer locations, the relevant corrective surgery may be chosen. Although some prophylactic procedures may be safe and effective, prophylactic hallux valgus correction in the diabetic foot requires further study.

Role of High-resolution Ultrasonography in the Evaluation of the Tibial and Median Nerves in Diabetic Peripheral Neuropathy

AIM

To evaluate and measure the mean cross-sectional area of the tibial and median nerves in patients with diabetic peripheral neuropathy, and to study the association between high-resolution ultrasonographic findings in diabetic peripheral neuropathy with the duration of illness, glycosylated haemoglobin values, random blood sugar levels, and aesthesiometry (using monofilament examination).

MATERIAL AND METHODS

A prospective observational study was conducted among 63 patients who were diagnosed with type 2 diabetes mellitus and underwent ultrasound and monofilament examinations. The cross-sectional area of the median nerve of the dominant hand and the tibial nerves was calculated on ultrasound examination.

RESULTS

The mean cross-sectional area of the median and tibial nerves was higher in patients with poor glycaemic control, with the mean cross-sectional area of the median nerve being 10.9, 12.8, 13.0, and 12.9 mm² at various points in the leg in cases where the monofilament examination was negative, as compared to 7.30, 7.78, 7.91, 7.87 mm² in patients with positive monofilament examination results. There was a significant positive correlation between the cross-sectional area of the tibial and median nerves and HbA_1c, duration of diabetes, aesthesiometry, and random blood sugar levels. With an increase in HbA_1c, duration of diabetes, and random blood sugar levels, there was a corresponding increase in the cross-sectional area of the nerves. These findings helped us to identify diabetic peripheral neuropathy.

CONCLUSIONS

High-resolution ultrasonography along with aesthesiometry and HbA_1c values can be an effective and easily available tool for detecting changes secondary to diabetic peripheral neuropathy. The method has a potential to replace or substitute nerve conduction tests in the near future.

Radiographic Bone Healing in Minimally Invasive Floating Metatarsal Osteotomy for Neuropathic Plantar Metatarsal Head Ulcers - A Retrospective Cohort Study

Minimally invasive floating metatarsal osteotomy is an option for treating neuropathic ulcers under the metatarsal heads. This study presents the radiographic results of the floating metatarsal osteotomy. We reviewed files and radiographs at least 4 months after a floating metatarsal osteotomy in patients with diabetic neuropathy. In 71 osteotomies in 54 patients with late onset diabetes (mean age 61 ± 9, mean HbA1c 7.9 ± 1.9%), the primary ulcer healed within 3.5 ± 1.4 weeks. Of 66 osteotomies where radiographs were available 10 had non-union (15%, all asymptomatic), 15 (23%) had hypertrophic callus formation and 41 (62%) had normal union. One patient developed an ulcer under the hypertrophic callus. This necessitated callus resection. Asymptomatic non-union may happen in 15% of floating osteotomies, but the osteotomies appear to be relatively safe and effective for neuropathic plantar metatarsal head ulcers. Hypertropic callus causing local re-ulceration is rare and can be managed surgically.

Prediction of callus and ulcer development in patients with diabetic peripheral neuropathy by isosceles triangle-forming tuning fork

Objectives:

Tuning fork vibration sensation testing is widely used as a diagnostic test to detect diabetic neuropathy. However, evidence-based literature indicates that reliability between examiners is low. Attaching isosceles triangle diagrams on tuning forks lowers the discrepancy between examiners. This study aimed to analyze the relationship between vibration sensation measurement using an improved tuning fork and the presence of callus and wound development in patients with diabetic peripheral neuropathy.

Methods:

Participants included 56 general older adults and 52 patients with diabetic peripheral neuropathy. The methods included confirmation of the presence or absence of callus, range of motion of the ankle and the first metatarsophalangeal joint, vibratory sensitivity of the medial malleolus and the dorsal aspect of the first distal phalanx using an improved tuning fork, and touch-pressure sensitivity of the plantar aspect of the hallux. Patients with diabetic peripheral neuropathy were followed up for 3 years to check for the presence or absence of wounds.

Results:

When compared with the general older adults, the patients with diabetic peripheral neuropathy had significantly lower touch-pressure sensitivity (p < 0.01), vibratory sensitivity at the distal phalanx (p < 0.01) and medial malleolus (p < 0.01), ankle dorsiflexion range of motion (p < 0.01), and metatarsophalangeal joint extension range of motion (p < 0.01). The area under the receiver operating characteristic curve with callus formation was 0.93 for the medial malleolus and 0.96 for the distal phalanx, indicating that the accuracy of the distal phalanx was higher (p < 0.01) than the medial malleolus. According to the Cox proportional hazard analysis, the vibratory sensitivity of the distal phalanx was a significant risk factor for ulcer development (p < 0.05).

Conclusion:

These findings suggest that the vibration sensation test, which we improved via the technique described in this study, is useful for predicting the occurrence of callus and ulcer.

Early Trajectory of Estimated Glomerular Filtration Rate and Long-term Advanced Kidney and Cardiovascular Complications in Type 1 Diabetes

OBJECTIVE

Rapid loss of estimated glomerular filtration rate (eGFR) within its normal range has been proposed as a strong predictor of future kidney disease. We investigated this association of eGFR slope early in the course of type 1 diabetes with long-term incidence of kidney and cardiovascular complications.

RESEARCH DESIGN AND METHODS

The annual percentage change in eGFR (slope) was calculated during the Diabetes Control and Complications Trial (DCCT) for each of 1,441 participants over a mean of 6.5 years and dichotomized by the presence or absence of early rapid eGFR loss (slope ≤-3% per year) as the exposure of interest. Outcomes were incident reduced eGFR (eGFR <60 mL/min/1.73 m2), composite cardiovascular events, or major adverse cardiovascular events (MACE) during the subsequent 24 years post-DCCT closeout follow-up.

RESULTS

At DCCT closeout (the baseline for this analysis), diabetes duration was 12 ± 4.8 years, most participants (85.9%) had normoalbuminuria, mean eGFR was 117.0 ± 13.4 mL/min/1.73 m2, and 149 (10.4%) had experienced early rapid eGFR loss over the preceding trial phase. Over the 24-year subsequent follow-up, there were 187 reduced eGFR (6.3 per 1,000 person-years) and 113 MACE (3.6 per 1,000 person-years) events. Early rapid eGFR loss was associated with risk of reduced eGFR (hazard ratio [HR] 1.81, 95% CI 1.18-2.79, P = 0.0064), but not after adjustment for baseline eGFR level (HR 0.94, 95% CI 0.53-1.66, P = 0.84). There was no association with composite cardiovascular events or MACE.

CONCLUSIONS

In people with type 1 diabetes primarily with normal eGFR and normoalbuminuria, the preceding slope of eGFR confers no additional association with kidney or cardiovascular outcomes beyond knowledge of an individual's current level.

Detection of diabetic polyneuropathy in a family medicine clinic by using monofilament

Background/Aim. Diabetic polyneuropathy (DPN) is the most common microvascular complication of diabetes mellitus (DM), which may be present at the time of disease detection. Screening for DPN is performed for the patients with type 2 diabetes at the time of diagnosis and for type 1 diabetes 5 years after diagnosis. The primary aim of this study was to determine the prevalence of DNP among family medicine patients with DM aged 18 to 70 years using nylon monofilament. Methods. The cross-sectional study estimated the prevalence of DPN among primary care patients with DM in Banja Luka, Republic of Srpska, Bosnia and Herzegovina. Semmes-Weinstein nylon 10 g monofilament was used to detect DPN. Age, gender, duration of DM, type of therapy, symptoms, glycosylated hemoglobin (HbA1c), and risk factors (hypertension, smoking, dyslipidemia, obesity, physical inactivity) were analyzed. Data collection took place from June 1st, 2017 to May 31st, 2018. Results. The study included 228 patients, 132 (57.9%) men and 96 (42.1%) women. There was a statistically significant difference in the presence of all symptoms of DPN (tingling, burning, light burning, and stinging) among patients with different duration of DM (p < 0.01). Multivariate logistic regression revealed that patients who had hypertension [odds ratio (OR) = 26.2; 95% confidence interval (CI): 4.070?168.488; p = 0.001], used oral anti-diabetic therapy (OR = 12.3; 95% CI: 1.300?116.309; p = 0.029), had tingling (OR = 5.2; 95% CI: 1.431?18.571; p = 0.012) and a longer duration of diabetes (OR = 4.27; 95% CI: 1.983?9.175; p = 0.000) were more likely to have DPN. Conclusion. The prevalence of DPN in family medicine patients with DM using nylon monofilament was 24.2%. Determinants of DNP were the presence of symptoms of tingling, duration of diabetes, hypertension, and the use of oral antidiabetic therapy alone.

PLANTAR SENSATION AND BALANCE IN PATIENTS WITH TYPE 2 DIABETES MELLITUS WITH AND WITHOUT PERIPHERAL NEUROPATHY

The aim of the study was to investigate the effect of diabetes on plantar sense and balance in patients with type 2 diabetes mellitus (T2DM). The study included 300 subjects divided into three groups: 100 T2DM patients with diabetic peripheral neuropathy (group 1); 100 T2DM patients without peripheral neuropathy (group 2); and 100 subjects without DM (group 3). Berg Balance Scale (BBS), Timed Up and Go test (TUG), single leg test with eyes open and closed, and plantar sensory tests were applied in the subjects. Study results showed significant differences in plantar sensory tests, BBS, TUG and single leg test among the three groups (p<0.05). In addition, duration of DM and medication were negatively correlated with single leg test both with eyes open and closed, but showed positive correlation with plantar sense and TUG test. Furthermore, the length of insulin therapy showed positive correlation with plantar sense and TUG test and negative correlation with BBS (p<0.05). In conclusion, DM has an effect on plantar sense and balance, and there is a relation between the duration of DM and balance problems. Balance problems are observed more often in patients with neuropathy.

Effect of Mini-invasive Floating Metatarsal Osteotomy on Plantar Pressure in Patients With Diabetic Plantar Metatarsal Head Ulcers

BACKGROUND

Distal metatarsal osteotomy has been used to alleviate plantar pressure caused by anatomic deformities. This study's purpose was to examine the effect of minimally invasive floating metatarsal osteotomy on plantar pressure in patients with diabetic metatarsal head ulcers.

METHODS

We performed a retrospective case series of prospectively collected data on 32 patients with diabetes complicated by plantar metatarsal head ulcers without ischemia. Peak plantar pressure and pressure time integrals were examined using the Tekscan MatScan prior to surgery and 6 months following minimally invasive floating metatarsal osteotomy. Patients were followed for complications for at least 1 year.

RESULTS

Peak plantar pressure at the level of the osteotomized metatarsal head decreased from 338.1 to 225.4 kPa (P < .0001). The pressure time integral decreased from 82.4 to 65.0 kPa·s (P < .0001). All ulcers healed within a mean of 3.7 ± 4.2 weeks. There was 1 recurrence (under a hypertrophic callus of the osteotomy) during a median follow-up of 18.3 months (range, 12.2-27). Following surgery, adjacent sites showed increased plantar pressure and 4 patients developed transfer lesions (under an adjacent metatarsal head); all were managed successfully. There was 1 serious adverse event related to surgery (operative site infection) that resolved with antibiotics.

CONCLUSION

This study showed that the minimally invasive floating metatarsal osteotomy successfully reduced local plantar pressure and that the method was safe and effective, both in treatment and prevention of recurrence.

LEVEL OF EVIDENCE

Level III, retrospective case series of prospectively collected data.

Thermal Perception Abnormalities Can Predict Diabetic Kidney Disease in Type 2 Diabetes Mellitus Patients

BACKGROUND

Previous studies have illustrated clinical associations between diabetic peripheral neuropathy (DPN) and diabetic kidney disease (DKD). Quantitative sensory testing (QST) can accurately detect thermal perception abnormalities and aid in the early diagnosis of asymptomatic small-fiber DPN in patients with type 2 diabetes. The aim of this study was to determine the predictive value of thermal perception abnormalities by QST to detect DKD.

METHODS

We prospectively enrolled 432 patients with type 2 diabetes (50.2% male, mean age 57.2 years, and average duration of diabetes 9.9 years) at our hospital between 2016 and 2017. Demographic and clinical data of the patients were recorded and analyzed. Diagnosis and staging of DKD were determined by urinary albumin excretion rate and estimated glomerular filtration rate. The presence of thermal perception abnormalities was determined by QST. Multiple logistic regression and receiver operating characteristic (ROC) analyses were performed to investigate the relationships between thermal perception abnormalities and DKD in these patients.

RESULTS

In multiple regression analysis, abnormal cold perception in the lower limbs was associated with an increased risk of advanced DKD. Area under the ROC curve analysis revealed that four-limb cold perception abnormalities had the best discriminatory power (0.741 ± 0.053) to predict advanced DKD.

CONCLUSIONS

Our results demonstrate the value of using thermal perception abnormalities to identify patients with type 2 diabetes also at risk of DKD.

Non-invasive assessment of vibration perception and protective sensation in people with diabetes mellitus: inter- and intra-rater reliability

BACKGROUND

Testing of protective sensation and vibration perception are two of the most commonly used non-invasive methods of screening for diabetes-related peripheral neuropathy (DPN). However, there is limited research investigating the reliability of these tests in people with diabetes. The aim of this study was to determine the inter- and intra-rater reliability of methods used to test vibration perception and protective sensation in a community-based population of adults with type 2 diabetes.

METHODS

Three podiatrists with varying clinical experience tested four- and 10-site, 10 g monofilament and vibration perception threshold (VPT). In a separate cohort, the reliability of a graduated tuning fork as well as two methods of conventional tuning fork (on/off method and dampening method) was undertaken by a new graduate podiatrist and podiatrist with one-year's clinical experience. The intra- (Cohen's К) and inter-rater (Cohen's or Fleiss' К) reliability of each test was determined.

RESULTS

Fifty participants (66% male, 100% type 2, 32% with DPN) underwent monofilament and neurothesiometer testing with 44 returning for the retest. Twenty-four participants (63% male, 100% type 2, 4% with DPN) underwent tuning fork testing and returned for retest. All tests demonstrated acceptable inter-rater reliability ranging from moderate (10-site monofilament, К: 0.54, CI: 0.38-0.70, p = 0.02) to substantial (graduated tuning fork, К: 0.68, CI: 0.41-0.95, p < 0.01). The 10-site monofilament (К: 0.44-0.77) outperformed the 4-site test (К: 0.34-0.67) and the dampened tuning fork method (К: 0.41-0.49) showed lower intra-rater reliability compared to both conventional (К: 0.52-0.57) and graduated methods (К: 0.50-0.57).

CONCLUSION

We support the current recommendations of using more than one test to screen and monitor progression of DPN. Four- and 10-site 10 g monofilament testing have similarly acceptable levels of reliability and the neurothesiometer is the most reliable method of assessing vibration perception function. Use of a graduated tuning fork was slightly more reliable than other methods of tuning fork application however all had substantial reliability. Years of clinical experience only marginally affected test reliability overall and due to subjective nature of the tests we suggest that testing should be performed regularly and repetitively.

Diabetic neuropathy

The global epidemic of prediabetes and diabetes has led to a corresponding epidemic of complications of these disorders. The most prevalent complication is neuropathy, of which distal symmetric polyneuropathy (for the purpose of this Primer, referred to as diabetic neuropathy) is very common. Diabetic neuropathy is a loss of sensory function beginning distally in the lower extremities that is also characterized by pain and substantial morbidity. Over time, at least 50% of individuals with diabetes develop diabetic neuropathy. Glucose control effectively halts the progression of diabetic neuropathy in patients with type 1 diabetes mellitus, but the effects are more modest in those with type 2 diabetes mellitus. These findings have led to new efforts to understand the aetiology of diabetic neuropathy, along with new 2017 recommendations on approaches to prevent and treat this disorder that are specific for each type of diabetes. In parallel, new guidelines for the treatment of painful diabetic neuropathy using distinct classes of drugs, with an emphasis on avoiding opioid use, have been issued. Although our understanding of the complexities of diabetic neuropathy has substantially evolved over the past decade, the distinct mechanisms underlying neuropathy in type 1 and type 2 diabetes remains unknown. Future discoveries on disease pathogenesis will be crucial to successfully address all aspects of diabetic neuropathy, from prevention to treatment.

Diabetic neuropathy

The global epidemic of prediabetes and diabetes has led to a corresponding epidemic of complications of these disorders. The most prevalent complication is neuropathy, of which distal symmetric polyneuropathy (for the purpose of this Primer, referred to as diabetic neuropathy) is very common. Diabetic neuropathy is a loss of sensory function beginning distally in the lower extremities that is also characterized by pain and substantial morbidity. Over time, at least 50% of individuals with diabetes develop diabetic neuropathy. Glucose control effectively halts the progression of diabetic neuropathy in patients with type 1 diabetes mellitus, but the effects are more modest in those with type 2 diabetes mellitus. These findings have led to new efforts to understand the aetiology of diabetic neuropathy, along with new 2017 recommendations on approaches to prevent and treat this disorder that are specific for each type of diabetes. In parallel, new guidelines for the treatment of painful diabetic neuropathy using distinct classes of drugs, with an emphasis on avoiding opioid use, have been issued. Although our understanding of the complexities of diabetic neuropathy has substantially evolved over the past decade, the distinct mechanisms underlying neuropathy in type 1 and type 2 diabetes remains unknown. Future discoveries on disease pathogenesis will be crucial to successfully address all aspects of diabetic neuropathy, from prevention to treatment.

Correlation Between Different Stages of Diabetic Nephropathy and Neuropathy in Patients with T2DM: A Cross-Sectional Controlled Study

INTRODUCTION

Early detection of diabetic peripheral neuropathy (DPN) is critical in patients with type 2 diabetes mellitus (T2DM) due to the lack of targeted therapy for DPN. We have investigated the relationship between different stages of diabetic nephropathy and DPN in an attempt to elucidate whether albuminuria can be used as an early warning signal of DPN progression.

METHODS

A total of 217 T2DM patients who met the inclusion criteria were recruited from the Department of Endocrinology, Nanfang Hospital between January 2016 and June 2016. These patients were placed in groups based on urinary albumin excretion rate (UAER) and estimated glomerular filtration rate. Nerve conduction studies, the Semmes-Weinstein monofilament test (SWMT) and the vibration perception threshold (VPT) test were conducted. Multiple linear regression analysis, multivariate logistic regression and receiver-operating characteristic (ROC) analysis were performed to investigate the relationship between different stages of diabetic nephropathy and DPN in these patients.

RESULTS

Significant differences were observed in the conduction velocity (CV) and amplitude of sensory/motor nerve potential among the T2DM patients at different stages of diabetic nephropathy (all p  < 0.05). The UAER and duration of diabetes were found to be independent factors associated with the mean CV and amplitude of sensory/motor nerve potential (all p  < 0.05). A disease duration of > 10 years (p  = 0.025) and a higher total cholesterol value (p  = 0.024) were found to be significantly associated with abnormal SWMT results. A UAER of > 300 mg/24 h (p  = 0.007) and a diastolic blood pressure of > 100 mmHg (p  = 0.042) were associated with a higher risk for abnormal VPT. A UAER  of > 300 mg/24 h (p  < 0.001) and a disease duration of > 10 years (p  = 0.02) were observed to be significantly correlated with DPN. The ROC analysis showed that the optimal cutoff values of UAER and duration as indicators of DPN were 90.5 mg/24 h and 9.5 years, respectively (both p  < 0.001).

CONCLUSIONS

The results suggest that diabetic nephropathy is closely associated with the development of DPN in T2DM patients and that UAER and disease duration can be used as warning indicators of DPN progression.

CHINESE CLINICAL TRIALS REGISTER NUMBER

ChiCTR-ROC-16007701.

Validity of a point-of-care nerve conduction device for polyneuropathy identification in older adults with diabetes: Results from the Canadian Study of Longevity in Type 1 Diabetes

Objective

Point-of-care nerve conduction devices (POCD) have been studied in younger patients and may facilitate screening for polyneuropathy in non-specialized clinical settings. However, performance may be impaired with advanced age owing to age-related changes in nerve conduction. We aimed to evaluate the validity of a POCD as a proxy for standard nerve conduction studies (NCS) in older adults with type 1 diabetes (T1D).

Methods

Sural nerve amplitude potential (AMP) and sural nerve conduction velocity (CV) was measured in 68 participants with ≥ 50 years T1D duration and 71 controls (from age/sex-matched subgroups) using POCD and NCS protocols. Agreement was determined by the Bland-Altman method, and validity was determined by receiver operating characteristic curves.

Results

T1D were 53% female, aged 66±8yr and had diabetes duration 54yr[52,58]. Controls were 56%(p = 0.69) female and aged 65±8yr(p = 0.36). Mean AMP_POCD and CV_POCD for the 139 participants was 7.4±5.8μV and 45.7±11.2m/s and mean AMP_NCS and CV_NCS was 7.2±6.1μV and 43.3±8.3m/s. Mean difference of AMP_POCD−AMP_NCS was 0.3±3.8μV and was 2.3±8.5m/s for CV_POCD−CV_NCS. A AMP_POCD of ≤6μV had 80% sensitivity and 80% specificity for identifying abnormal AMP_NCS, while a CV_POCD of ≤44m/s had 81% sensitivity and 82% specificity to identify abnormal CV_NCS. Abnormality in AMP_POCD or CV_POCD was associated with 87% sensitivity, while abnormality in both measures was associated with 97% specificity for polyneuropathy identification.

Conclusions

The POCD has strong agreement and diagnostic accuracy for identification of polyneuropathy in a high-risk subgroup and thus may represent a sufficiently accurate and rapid test for routinely detecting those with electrophysiological dysfunction.

Assessment of diabetic polyneuropathy in Zanzibar: Comparison between traditional methods and an automated point-of-care nerve conduction device

•

We screened for signs of neuropathy in a diabetes population in Zanzibar.

•

Nerve conduction study by NC-stat DPNCheck found neuropathy in 45%.

•

Monofilament results suggestive of neuropathy in 61%.

•

Compared to nerve conduction study, monofilament had a 59% specificity.

•

Hyperglycaemia and hypertension are highly prevalent risk factors in this population.

Aim

Scant information is available about the prevalence of diabetic polyneuropathy, as well as the applicability of screening tools in sub-Saharan Africa. We aimed to investigate these issues in Zanzibar (Tanzania).

Methods

One hundred consecutive diabetes patients were included from the diabetes clinic at Mnazi Mmoja Hospital. Clinical characteristics were recorded. Further, we investigated: a) self-reported numbness of the lower limbs, b) ten-point monofilament test, c) the Sibbald 60-s Tool and d) nerve conduction studies (NCS, using an automated handheld point-of-care device, the NC-stat DPNCheck).

Results

Mean age was 54 years, 90% had type 2 diabetes, and with 9 year average disease duration. Mean HbA1c was 8.5% (69 mmol/mol), blood pressure 155/88 mmHg. Sixty-two% reported numbness, 61% had positive monofilament and 79% positive Sibbald tool. NCS defined neuropathy in 45% of the patients. Only the monofilament showed appreciable concordance with the NCS, Cohen’s κ 0.43.

Conclusions

The patient population was characterised by poor glycaemic control and hypertension. In line with this, neuropathy was rampant. The monofilament test tended to define more cases of probable neuropathy than the NCS, however specificity was rather low. Plantar skin thickening may have led to false positives in this population. Overall concordance was, however, appreciable, and could support continued use of monofilament as a neuropathy screening tool. The NC-stat DPNCheck could be useful in cases of diagnostic uncertainty or for research purposes in a low resource setting.

Plantar pressures are elevated in people with longstanding diabetes-related foot ulcers during follow-up

Objective

High plantar pressures are implicated in the development of diabetes-related foot ulcers. Whether plantar pressures remain high in patients with chronic diabetes-related foot ulcers over time is uncertain. The primary aim of this study was to compare plantar pressures at baseline and three and six months later in participants with chronic diabetes-related foot ulcers (cases) to participants without foot ulcers (controls).

Methods

Standardised protocols were used to measure mean peak plantar pressure and pressure-time integral at 10 plantar foot sites (the hallux, toes, metatarsals 1 to 5, mid-foot, medial heel and lateral heel) during barefoot walking. Measurements were performed at three study visits: baseline, three and six months. Linear mixed effects random-intercept models were utilised to assess whether plantar pressures differed between cases and controls after adjusting for age, sex, body mass index, neuropathy status and follow-up time. Standardised mean differences (Cohen’s d) were used to measure effect size.

Results

Twenty-one cases and 69 controls started the study and 16 cases and 63 controls completed the study. Cases had a higher mean peak plantar pressure at several foot sites including the toes (p = 0.005, Cohen’s d = 0.36) and mid-foot (p = 0.01, d = 0.36) and a higher pressure-time integral at the hallux (p<0.001, d = 0.42), metatarsal 1 (p = 0.02, d = 0.33) and mid-foot (p = 0.04, d = 0.64) compared to controls throughout follow-up. A reduction in pressure-time integral at multiple plantar sites over time was detected in all participants (p<0.05, respectively).

Conclusions

Plantar pressures assessed during gait are higher in diabetes patients with chronic foot ulcers than controls at several plantar sites throughout prolonged follow-up. Long term offloading is needed in diabetes patients with diabetes-related foot ulcers to facilitate ulcer healing.

Nonalcoholic fatty liver disease is associated with an increased prevalence of distal symmetric polyneuropathy in adult patients with type 1 diabetes

AIMS

Presently, data on the association between nonalcoholic fatty liver disease (NAFLD) and distal symmetric polyneuropathy in people with diabetes are scarce and conflicting. The aim of this retrospective, cross-sectional study was to examine whether NAFLD was associated with an increased prevalence of distal symmetric polyneuropathy in type 1 diabetic adults.

METHODS

We studied all white type 1 diabetic outpatients (n = 286, 42.3% male, mean age 43 ± 14 years, median diabetes duration 17 [10-30] years), who participated in a foot screening program at our adult diabetes clinic after excluding those who had excessive alcohol consumption and other known causes of chronic liver disease. NAFLD was diagnosed by ultrasonography. Distal symmetric polyneuropathy was detected using the Michigan Neuropathy Screening Instrument method and the biothesiometer Vibrotest.

RESULTS

Overall, the prevalence rates of NAFLD and distal symmetric polyneuropathy were 52.4% and 35.3%, respectively. Patients with NAFLD had a substantially increased prevalence of distal symmetric polyneuropathy compared to their counterparts without NAFLD (51.0% vs. 17.1%, p < 0.001). In univariate analysis, NAFLD was associated with an approximately 5-fold increased risk of prevalent distal symmetric polyneuropathy (odds ratio [OR] 5.32, 95% confidence interval [CI] 3.1-9.3, p < 0.001). This association remained significant even after adjustment for age, sex, diabetes duration, hemoglobin A1c, diabetic retinopathy, smoking, metabolic syndrome, chronic kidney disease and carotid artery stenoses ≥ 40% (adjusted-OR 2.23, 95% CI 1.1-4.8, p < 0.05).

CONCLUSIONS

Our results show that NAFLD, diagnosed by ultrasonography, is strongly associated with an increased risk of distal symmetric polyneuropathy in type 1 diabetic adults, independently of several cardio-metabolic risk factors.

Diagnostic Accuracy of Monofilament Tests for Detecting Diabetic Peripheral Neuropathy: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically evaluate the diagnostic accuracy of monofilament tests for detecting diabetic peripheral neuropathy.

METHODS

We searched EMBASE (OvidSP), MEDLINE (OvidSP), the Cochrane Library, and Web of Science to identify diagnostic accuracy trials of monofilament tests for detecting diabetic peripheral neuropathy. We used a hierarchical summary receiver operating characteristics (HSROC) model to conduct the meta-analysis of diagnostic accuracy of monofilament tests for detecting diabetic peripheral neuropathy.

RESULTS

A total of 19 comparative trials met the inclusion criteria and were part of the qualitative synthesis. Eight trials using nerve conduction studies as the reference standard were selected for the meta-analysis. The pooled sensitivity and specificity of monofilament tests for detecting diabetic peripheral neuropathy were 0.53 (95% confidence interval (CI) 0.32 to 0.74) and 0.88 (95% CI 0.78 to 0.94), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 4.56 (95% CI 2.93 to 7.10) and 0.53 (95% CI 0.35 to 0.81), respectively.

CONCLUSIONS

Our review indicated that monofilament tests had limited sensitivity for screening diabetic peripheral neuropathy. The clinical use of the monofilament test in the evaluation of diabetic peripheral neuropathy cannot be encouraged based on currently available evidence.

[Orthostatic hypotension; that great unknown]

Orthostatic hypotension is an anomaly of growing interest in scientific research. Although certain neurogenic diseases are associated with this phenomenon, it can also be associated with non-neurological causes. Although orthostatic hypotension is defined by consensus as a decrease in the systolic blood pressure of at least 20mmHg, or a decrease in diastolic blood pressure of at least 10mmHg, within 3min of standing, the studies differ on how to diagnose it. Orthostatic hypotension is associated with certain cardiovascular risk factors and with drug treatment, but the results are contradictory. The purpose of this review is to update the knowledge about orthostatic hypotension and its treatment, as well as to propose a method to standardise its diagnosis.

The Need for Improved Management of Painful Diabetic Neuropathy in Primary Care

The provision of care for patients with type II diabetes in primary care must involve assessing patients for peripheral neuropathy of the feet. Objectives. This paper will demonstrate that painful diabetic neuropathy (PDN) is poorly assessed for and treated in primary care. Methods. A critical analysis of research will be conducted to identify the prevalence and impact of PDN among individuals with type II diabetes. Results. Research evidence and best practice guidelines are widely available in supporting primary care practitioners to better assess for and treat PDN. However, the lack of knowledge, awareness, and implementation of such research and guidelines prevents patients with PDN from receiving appropriate care. Discussion. Much international research exists on the prevalence and impact of PDN in primary care; however, Canadian research is lacking. Furthermore, the quantity and quality of research on treatment modalities for PDN are inadequate. Finally, current research and guidelines on PDN management are inadequately implemented in the clinical setting. Conclusion. The undertreatment of PDN has significant implications on the individual, family, and society. Healthcare practitioners must be more aware of and better implement current research and guidelines into practice to resolve this clinical issue.

Prediction of protective sensory loss, neuropathy and foot ulceration in type 2 diabetes

OBJECTIVES

To prospectively determine clinical and biochemical characteristics associated with the development of peripheral neuropathy, loss of protective sensation, and foot ulceration in persons with type 2 diabetes mellitus (DM) over 7 years.

RESEARCH DESIGN AND METHODS

Graded monofilament (MF) testing, vibration perception threshold, and neuropathy symptom questionnaires were undertaken in 206 participants with type 2 DM without peripheral vascular disease or history of foot ulceration and 71 healthy participants without DM at baseline and after 7 years. 6 monthly glycosylated hemoglobin (HbA1c) levels and annual serum lipid profiles were measured during follow-up of those with DM. Incident foot ulceration was recorded at follow-up.

RESULTS

Taller stature and higher quartiles of serum triglyceride and HbA1c levels were associated with neuropathy at follow-up (p=0.008). Remission of baseline neuropathy was observed in 7 participants at follow-up. 9 participants with type 2 DM developed foot ulcers by the end of the study, only 1 at low risk. Mean HbA1c levels were higher in those who developed foot ulceration (p<0.0001). 1 participant with neuropathy throughout developed a Charcot foot. Failure to perceive 2 or more 2, 4 and 6 g MF stimuli at baseline predicted loss of protective sensation at follow-up.

CONCLUSIONS

Tall stature and worse metabolic control were associated with progression to neuropathy. Mean HbA1c levels were higher in those who developed foot ulcers. Graded MF testing may enrich recruitment to clinical trials and assignation of high risk for foot ulceration.

Serum Phosphorylated Neurofilament-Heavy Chain, a Potential Biomarker, is Associated With Peripheral Neuropathy in Patients With Type 2 Diabetes

Neurofilament (NF), one of the major axonal cytoskeletal proteins, plays a critical role in degenerative diseases in both the central and the peripheral nervous systems. The aim of this study is to explore the relationship between serum phosphorylated neurofilament-heavy chain (pNF-H) and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes.Serum pNF-H concentrations were measured by ELISA in hospitalized patients with and without DPN (n = 118). DPN was assessed by clinical symptoms, signs, and electromyography.Compared with the non-DPN group (311.98 [189.59-634.12] pg/mL), the confirmed group (605.99 [281.17-1332.78] pg/mL) patients had the higher serum pNF-H levels (P = 0.007). DPN was significantly correlated with C-peptide (r = -0.269), total cholesterol (TC) (r = 0.185), and pNF-H (r = 0.258). Serum pNF-H levels were independently associated with DPN (P = 0.004), even after adjusting for age, sex, duration of diabetes, fasting plasma glucose, glycosylated hemoglobin A1c, TC, C-peptide, urinary albuminto/creatinine ratio, and estimated glomerular filtration rate. Compared with pNF-H quartile 1 (referent), patients in quartile 3 (odds ratio [OR], 3.977; 95% confidence interval [CI], 1.243-12.728; P = 0.021) and quartile 4 (OR, 10.488; 95% CI, 3.020-34.429; P = 0.000) had the higher risk of DPN after adjusting for the confounders.Serum pNF-H levels might be associated with the DPN, and the correlationship between serum pNF-H and DPN should be further studied.

Prevalence of neuropathy in type 2 diabetic patients and its association with other diabetes complications: The Verona Diabetic Foot Screening Program

AIMS

Somatic neuropathy is a chronic complication of diabetes. The purpose of our study was to determine prevalence and clinical variables associated with somatic neuropathy applying a simple screening method.

METHODS

All outpatients with type 2 diabetes attending our diabetic clinic were offered to participate into a diabetic foot screening program, in the period January 2004-December 2012. A total of 3,591 diabetic patients (55.5% men, age 68±10years) underwent detection of somatic neuropathy using the Michigan Neuropathy Screening Instrument in its parts of symptoms (administering a questionnaire) and clinical assessment slightly modified (evaluating foot inspection, vibration sensation by biothesiometer, ankle reflexes).

RESULTS

The prevalence of somatic neuropathy was 2.2% in men and 5.5% in women (p<0.001) when assessed by symptom questionnaire, whereas it was 30.5% in men and 30.8% (p=NS) in women when identified by clinical assessment. In subjects with somatic neuropathy macro- and microvascular complications of diabetes were significantly more common. In multivariate logistic regression analyses BMI, HbA1c and ankle/brachial index independently predicted the presence of neuropathy.

CONCLUSION

The prevalence of somatic neuropathy in type 2 diabetes is nearly 30% when searched with clinical examination. Poor metabolic control, excess body weight and peripheral arteriopathy are independent markers of somatic neuropathy.

Lower limb biomechanical characteristics of patients with neuropathic diabetic foot ulcers: the diabetes foot ulcer study protocol

BACKGROUND

Foot ulceration is the main precursor to lower limb amputation in patients with type 2 diabetes worldwide. Biomechanical factors have been implicated in the development of foot ulceration; however the association of these factors to ulcer healing remains less clear. It may be hypothesised that abnormalities in temporal spatial parameters (stride to stride measurements), kinematics (joint movements), kinetics (forces on the lower limb) and plantar pressures (pressure placed on the foot during walking) contribute to foot ulcer healing. The primary aim of this study is to establish the biomechanical characteristics (temporal spatial parameters, kinematics, kinetics and plantar pressures) of patients with plantar neuropathic foot ulcers compared to controls without a history of foot ulcers. The secondary aim is to assess the same biomechanical characteristics in patients with foot ulcers and controls over-time to assess whether these characteristics remain the same or change throughout ulcer healing.

METHODS/DESIGN

The design is a case-control study nested in a six-month longitudinal study. Cases will be participants with active plantar neuropathic foot ulcers (DFU group). Controls will consist of patients with type 2 diabetes (DMC group) and healthy participants (HC group) with no history of foot ulceration. Standardised gait and plantar pressure protocols will be used to collect biomechanical data at baseline, three and six months. Descriptive variables and primary and secondary outcome variables will be compared between the three groups at baseline and follow-up.

DISCUSSION

It is anticipated that the findings from this longitudinal study will provide important information regarding the biomechanical characteristic of type 2 diabetes patients with neuropathic foot ulcers. We hypothesise that people with foot ulcers will demonstrate a significantly compromised gait pattern (reduced temporal spatial parameters, kinematics and kinetics) at base line and then throughout the follow-up period compared to controls. The study may provide evidence for the design of gait-retraining, neuro-muscular conditioning and other approaches to off-load the limbs of those with foot ulcers in order to reduce the mechanical loading on the foot during gait and promote ulcer healing.

New ophthalmologic imaging techniques for detection and monitoring of neurodegenerative changes in diabetes: a systematic review

Optical coherence tomography (OCT) of the retina and around the optic nerve head and corneal confocal microscopy (CCM) are non-invasive and repeatable techniques that can quantify ocular neurodegenerative changes in individuals with diabetes. We systematically reviewed studies of ocular neurodegenerative changes in adults with type 1 or type 2 diabetes and noted changes in the retina, the optic nerve head, and the cornea. Of the 30 studies that met our inclusion criteria, 14 used OCT and 16 used CCM to assess ocular neurodegenerative changes. Even in the absence of diabetic retinopathy, several layers in the retina and the mean retinal nerve fibre layer around the optic nerve head were significantly thinner (-5·36 μm [95% CI -7·13 to -3·58]) in individuals with type 2 diabetes compared with individuals without diabetes. In individuals with type 1 diabetes without retinopathy none of the intraretinal layer thicknesses were significantly reduced compared with individuals without diabetes. In the absence of diabetic polyneuropathy, individuals with type 2 diabetes had a lower nerve density (nerve branch density: -1·10/mm(2) [95% CI -4·22 to 2·02]), nerve fibre density: -5·80/mm(2) [-8·06 to -3·54], and nerve fibre length: -4·00 mm/mm(2) [-5·93 to -2·07]) in the subbasal nerve plexus of the cornea than individuals without diabetes. Individuals with type 1 diabetes without polyneuropathy also had a lower nerve density (nerve branch density: -7·74/mm(2) [95% CI -14·13 to -1·34], nerve fibre density: -2·68/mm(2) [-5·56 to 0·20]), and nerve fibre length: -2·58 mm/mm(2) [-3·94 to -1·21]). Ocular neurodegenerative changes are more evident when diabetic retinopathy or polyneuropathy is present. OCT and CCM are potentially useful, in addition to conventional clinical methods, to assess diabetic neurodegenerative changes. Additional research is needed to determine their incremental benefit and to standardise procedures before the application of OCT and CCM in daily practice.

Association study of C936T polymorphism of the VEGF gene and the C242T polymorphism of the p22phox gene with diabetes mellitus type 2 and distal diabetic polyneuropathy

Even with long‑term glycemic control, diabetes mellitus type 2 (DM2) remains the predominant cause of diabetic neuropathy. Single nucleotide polymorphism (SNP) C936T of the vascular endothelial growth factor (VEGF) gene and the SNP C242T of the p22phox (CYBA) gene have been investigated in relation to DM2 and its complications. The aim of the present study was to investigate the association between these two SNPs and DM2, and also between the SNPs and the signs and symptoms of diabetic distal polyneuropathy. The DM2 group consisted of 98 individuals and the control group consisted of 104 individuals. The results demonstrated that there was no association between the different genotypes or alleles and increased risk of the disease (P>0.05). With SNP C242T, a significant association with body mass index between the CTxTT genotypes (P=0.043) was identified; and the greatest body mass indexes were among individuals with the TT genotype. An association between the degree of neuropathic symptoms and genotypic/allelic distribution of these polymorphisms was not observed. In conclusion, the investigated polymorphisms are not correlated with the risk of developing DM2.

In vivo corneal confocal microscopy and prediction of future-incident neuropathy in type 1 diabetes: a preliminary longitudinal analysis

OBJECTIVE

In vivo corneal confocal microscopy (IVCCM) has been established in cross-sectional studies as a valid measure for the identification of diabetic sensorimotor polyneuropathy (DSP). We aimed to determine the predictive validity of a baseline IVCCM measure in identifying future DSP onset in patients with type 1 diabetes.

METHODS

We followed 65 patients with type 1 diabetes without DSP at baseline. They were followed longitudinally for a mean of 3.5±0.9 years and underwent IVCCM, clinical and electrophysiologic examinations at baseline and follow up. At the end of follow up, participants were assigned as new-onset cases of DSP or as controls. Predictive validity was assessed using receiver operating characteristic curves.

RESULTS

At baseline, participants were 34±15 years of age with mean diabetes duration of 18±12 years. The 11 (17%) new-onset cases of DSP were similar to the 54 (83%) controls in baseline age, diabetes duration, gender, glycated hemoglobin levels and electrophysiologic parameters (p≥0.20). However, cases of new onset had significantly lower baseline corneal nerve fibre length (CNFL) and branch density (p<0.05). For identification of new-onset cases, area under the receiver operating characteristic curve for CNFL was 0.78 with an optimal threshold of 14.9 mm/mm(2) (sensitivity=0.82, specificity=0.69).

CONCLUSIONS

Despite similar clinical and electrophysiologic parameters, participants with type 1 diabetes at risk for future DSP had significantly lower baseline IVCCM measures. CNFL may have applicability in identifying high-risk patients for therapeutic intervention in clinical research and practice.

Corneal confocal microscopy predicts 4-year incident peripheral neuropathy in type 1 diabetes

OBJECTIVE

This study determined if deficits in corneal nerve fiber length (CNFL) assessed using corneal confocal microscopy (CCM) can predict future onset of diabetic peripheral neuropathy (DPN).

RESEARCH DESIGN AND METHODS

CNFL and a range of other baseline measures were compared between 90 nonneuropathic patients with type 1 diabetes who did or did not develop DPN after 4 years. The receiver operator characteristic (ROC) curve was used to determine the capability of single and combined measures of neuropathy to predict DPN.

RESULTS

DPN developed in 16 participants (18%) after 4 years. Factors predictive of 4-year incident DPN were lower CNFL (P = 0.041); longer duration of diabetes (P = 0.002); higher triglycerides (P = 0.023); retinopathy (higher on the Early Treatment of Diabetic Retinopathy Study scale) (P = 0.008); nephropathy (higher albumin-to-creatinine ratio) (P = 0.001); higher neuropathy disability score (P = 0.037); lower cold sensation (P = 0.001) and cold pain (P = 0.027) thresholds; higher warm sensation (P = 0.008), warm pain (P = 0.024), and vibration (P = 0.003) thresholds; impaired monofilament response (P = 0.003); and slower peroneal (P = 0.013) and sural (P = 0.002) nerve conduction velocity. CCM could predict the 4-year incident DPN with 63% sensitivity and 74% specificity for a CNFL threshold cutoff of 14.1 mm/mm(2) (area under ROC curve = 0.66, P = 0.041). Combining neuropathy measures did not improve predictive capability.

CONCLUSIONS

DPN can be predicted by various demographic, metabolic, and conventional neuropathy measures. The ability of CCM to predict DPN broadens the already impressive diagnostic capabilities of this novel ophthalmic marker.

Measurement of cooling detection thresholds for identification of diabetic sensorimotor polyneuropathy in type 1 diabetes

Objective

Compared to recently-studied novel morphological measures, conventional small nerve fiber functional tests have not been systematically studied for identification of diabetic sensorimotor polyneuropathy (DSP). We aimed to determine and compare the diagnostic performance of cooling detection thresholds (CDT) in a cross-sectional type 1 diabetes cohort.

Research Design and Methods

136 subjects with type 1 diabetes and 52 healthy volunteers underwent clinical and electrophysiological examination for DSP classification concomitantly with the Toronto Clinical Neuropathy Score (TCNS) and three small fiber function tests: CDT, heart rate variability (HRV), and laser doppler imaging of axon-mediated neurogenic flare responses to cutaneous heating (LDI_FLARE). Area under the curve (AUC) and optimal thresholds were determined by receiver operating characteristic (ROC) curves in the type 1 diabetes cohort.

Results

Type 1 diabetes subjects were 42±17 years of age with mean HbA1c 7.9±1.7%. Fifty-nine (45%) met the case definition for DSP. CDT values were lowest in cases with DSP (18.3±8.4°C) compared to controls without DSP (28.4±3.5°C) and to healthy volunteers (29.6±1.8°C; p-value for both comparisons<0.0001). AUC_CDT was 0.863 which was similar to AUC_TCNS (0.858, p = 0.24) and AUC_HRV (0.788, p = 0.05), but exceeded AUC_LDIFLARE (0.750, p = 0.001). The threshold of <25.1°C was equivalent to the lower bound of the healthy volunteer 95% distribution [25.1, 30.8°C] and performed with 83% sensitivity and 82% specificity.

Conclusions

Akin to novel small fiber morphological measures, CDT is a functional test that identifies DSP with very good diagnostic performance. These findings support further research that revisits the role of CDT in early DSP detection.

Neuromuscular complications of diabetes mellitus

PURPOSE OF REVIEW

Diabetes mellitus has become a modern global epidemic, with steadily increasing prevalence rates related to lifestyle such that 27% of individuals aged 65 years or older have diabetes mellitus, 95% of whom have type 2. This article reviews the effects of diabetes mellitus on the neuromuscular system.

RECENT FINDINGS

Diabetes mellitus leads to diverse forms of peripheral neuropathy as the major neuromuscular complication. Both focal and diffuse types of neuropathy can develop, with the most common form being diabetic sensorimotor polyneuropathy. Small fibers are damaged early in the development of diabetic sensorimotor polyneuropathy and are not assessed by nerve conduction studies. Small fiber damage occurs even in the prediabetes stage. No disease-modifying therapy for diabetic sensorimotor polyneuropathy is available at this time, but this complication can be limited in patients who have type 1 diabetes mellitus with strict glycemic control; the same outcome is not clearly observed in patients who have type 2 diabetes mellitus. Recently, the evidence base for symptomatic treatments of painful diabetic sensorimotor polyneuropathy underwent systematic review. Effective evidence-based treatments include some anticonvulsants (eg, pregabalin, gabapentin), antidepressants (eg, amitriptyline, duloxetine), opioids (eg, morphine sulfate, oxycodone), capsaicin cream, and transcutaneous electrical nerve stimulation.

SUMMARY

This article reviews the increasing prevalence of diabetes mellitus and diabetic sensorimotor polyneuropathy and discusses recent consensus opinion on the objective confirmation needed for the diagnosis in the clinical research setting. The evidence from clinical trials shows that intensive glycemic control reduces prevalence of diabetic sensorimotor polyneuropathy in patients with type 1 diabetes mellitus, but variable outcomes are observed in patients with type 2 diabetes mellitus. Finally, despite the lack of disease-modifying treatment, effective evidence-based therapy can control painful symptoms of diabetic sensorimotor polyneuropathy.

Evaluation of clinical tools and their diagnostic use in distal symmetric polyneuropathy

AIMS

To compare the diagnostic usefulness of tuning fork, monofilament, biothesiometer and skin biopsies in peripheral neuropathy in individuals with varying glucose metabolism.

METHODS

Normoglycaemic, impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) individuals were recruited. Nerve conduction studies (NCS) and thermal threshold tests were performed. Vibrotactile sense was tested with a biothesiometer and a 128-Hz tuning fork. Touch/pressure perception was examined with a 10-g monofilament. Skin biopsies were performed and intraepidermal nerve fibres were quantified. Distal symmetric polyneuropathy (DSPN) was defined as neuropathy disability score ≥2 and abnormal NCS. Thermal threshold tests were used to define small nerve fibre neuropathy (sDSPN) in cases where NCS (large nerve fibres) were normal.

RESULTS

The prevalence of DSPN and sDSPN in the whole group (n=119) was 18% and 23%, respectively. For the biothesiometer, a cut-off of ≥24.5V had a sensitivity of 82% and specificity of 70% (AUC=0.81, 95% CI 0.71-0.91) when evaluating DSPN. An intraepidermal nerve fibre density cut-off of ≤3.39fibres/mm showed a sensitivity of 74% and specificity of 70% in the detection of sDSPN, whereas the sensitivity of the tuning fork and the biothesiometer were relatively low, 46% and 67%, respectively. When combining skin biopsies with the tuning fork, 10 more sDSPN cases were identified. Adding skin biopsy to the combination of the tuning fork and biothesiometer increased the sensitivity of finding sDSPN cases, but not DSPN, from 81% to 93%.

CONCLUSION

Using a biothesiometer in clinical routine might be a sensitive method to detect large nerve fibre dysfunction in the lower extremity, whereas skin biopsies in combination with methods measuring vibrotactile sense could increase the diagnostic sensitivity of detecting peripheral neuropathy at an early stage.

Reliability and validity of a point-of-care sural nerve conduction device for identification of diabetic neuropathy

BACKGROUND

Confirmation of diabetic sensorimotor polyneuropathy (DSP) relies on standard nerve conduction studies (NCS) performed in specialized clinics. We explored the utility of a point-of-care device (POCD) for DSP detection by nontechnical personnel and a validation of diagnostic thresholds with those observed in a normative database.

RESEARCH DESIGN AND METHODS

44 subjects with type 1 and type 2 diabetes underwent standard NCS (reference method). Two nontechnical examiners measured sural nerve amplitude potential (SNAP) and conduction velocity (SNCV) using the POCD. Reliability was determined by intraclass correlation coefficients (ICC [2], [1]). Validity was determined by Bland-Altman analysis and receiver operating characteristic curves.

RESULTS

The 44 subjects (50% female) with mean age 56 ± 18 years had mean SNAP and SNCV of 8.0 ± 8.6 µV and 41.5 ± 8.2 m/s using standard NCS and 8.0 ± 8.2 µV and 49.9 ± 11.1 m/s using the POCD. Intrarater reproducibility ICC values were 0.97 for SNAP and 0.94 for SNCV while interrater reproducibility values were 0.83 and 0.79, respectively. Mean bias of the POCD was -0.1 ± 3.6 µV for SNAP and +8.4 ± 6.4 m/s for SNCV. A SNAP of ≤6 µV had 88% sensitivity and 94% specificity for identifying age-and height-standardized reference NCS values, while a SNCV of ≤48 m/s had 94% sensitivity and 82% specificity [corrected].. Abnormality in one or more of these thresholds was associated with 95% sensitivity and 71% specificity for identification of DSP according to electrophysiological criteria.

CONCLUSIONS

The POCD demonstrated excellent reliability and acceptable accuracy. Threshold values for DSP identification validated those of published POCD normative values. We emphasize the presence of measurement bias--particularly for SNCV--that requires adjustment of threshold values to reflect those of standard NCS.

Glucose control and diabetic neuropathy: lessons from recent large clinical trials

Diabetic peripheral and autonomic neuropathies are common complications of diabetes with broad spectrums of clinical manifestations and high morbidity. Studies using various agents to target the pathways implicated in the development and progression of diabetic neuropathy were promising in animal models. In humans, however, randomized controlled studies have failed to show efficacy on objective measures of neuropathy. The complex anatomy of the peripheral and autonomic nervous systems, the multitude of pathogenic mechanisms involved, and the lack of uniformity of neuropathy measures have likely contributed to these failures. To date, tight glycemic control is the only strategy convincingly shown to prevent or delay the development of neuropathy in patients with type 1 diabetes and to slow the progression of neuropathy in some patients with type 2 diabetes. Lessons learned about the role of glycemic control on distal symmetrical polyneuropathy and cardiovascular autonomic neuropathy are discussed in this review.

Influence of the Location of Nonischemic Diabetic Forefoot Osteomyelitis on Time to Healing After Undergoing Surgery

The forefoot has been reported as the most frequent location of osteomyelitis in the feet of patients with diabetes. The forefoot includes toes and metatarsal heads as common locations of bone infections, but the anatomy of these bones is quite different. As a result, such differences in anatomy may have an impact on the outcomes. The aim of the present study was to determine whether different locations of osteomyelitis in the forefoot have any influence on time to healing after undergoing surgery in a prospective series including 195 patients without peripheral arterial disease and osteomyelitis confirmed by histopathology. Location of the lesion was classified into 4 groups: hallux, first metatarsal head, lesser metatarsal heads, and lesser toes. The time required to achieve healing and the cumulative rate of wounds healed and likelihood of healing were analyzed at 4, 8, and 12 weeks after surgery. Time of healing (mean ± SD) in the whole series was 10.7 ± 8.4 weeks. Osteomyelitis located in the lesser toes has a higher probability of healing by the fourth week (odds ratio [OR] = 5.7, 95% confidence interval [CI] = 2.8-11.6, P < .001), eighth week (OR = 3.2, 95% CI = 1.6-6.4, P < .001), or twelfth week (OR = 3.1, 95% CI = 1.3-7.0, P = .008) than other osteomyelitis locations. Osteomyelitis located in the first metatarsal joint was less likely to heal by the eighth week (OR = 0.4, 95% CI = 0.2-0.9, P = .037) and 12th week (OR = 0.4, 95% CI = 0.2-1.0, P = .040). In conclusion, time to healing is significantly different according to the location of the bone infection in the forefoot.

Chronic pain with neuropathic characteristics in diabetic patients: a French cross-sectional study

OBJECTIVE

Our aim was to estimate the prevalence of distal chronic pain with neuropathic characteristics in patients with type 1 and type 2 diabetes mellitus and its impact on quality of life, mood, anxiety, sleep and healthcare utilization.

METHODS

In total, 885 patients were screened and 766 diabetic patients (38.7% with type 1 diabetes mellitus, 44.8% women, mean age: 57.2 ± 14.9 years) were enrolled consecutively over a three-month period in this observational study by 85 diabetes specialists working in a hospital department or in private practice. All the patients completed a series of questionnaires for the detection of chronic pain (i.e. daily pain for more than three months) in the lower limbs and assessment of health-related quality of life (Medical Outcomes Short Form 12 scale), sleep disturbances (MOS sleep scale), depression and anxiety (Hospital Anxiety and Depression scale). Patients with chronic pain were also assessed with the 7-item DN4-interview questionnaire, the monofilament test and the Michigan Neuropathy Screening Instrument (MNSI).

RESULTS

The overall prevalence of chronic pain with neuropathic characteristics was 20.3% [95% CI 17.4-23.1]. The MNSI examination score suggested that pain was related to polyneuropathy, in 80.1% of these patients (89.5% of those with bilateral pain). Patients with chronic pain had a poorer quality of life and more sleep disturbances, anxiety and depression than patients without pain and the presence of neuropathic characteristics was predictive of such impairments. Only 38.6% of the patients had received appropriate treatment for neuropathic pain.

CONCLUSIONS

Chronic pain with neuropathic characteristics concerns one in five diabetic patients, has a significant impact on quality of life and is not adequately managed. The close correlation between the DN4 questionnaire and MNSI results suggests that screening tools for neuropathic pain could be used in daily practice for the identification of painful diabetic polyneuropathy.