Diabetes mellitus as a risk factor for compression neuropathy: a longitudinal cohort study from southern Sweden

Exploring the causal relationships between type 2 diabetes and neurological disorders using a Mendelian randomization strategy

While there is ample evidence indicating an increased occurrence of general neurological conditions among individuals with diabetes, there has been limited exploration into the cause-and-effect connection between type 2 diabetes (T2D) and specific neurological disorders, including conditions like carpal tunnel syndrome and Bell's palsy. We used Mendelian randomization (MR) approach to investigate the causal effects of T2D on 67 neurological diseases. We primarily utilized the inverse-variance weighted method for the analysis, and also employed the weighted median and MR-Egger methods in our study. To detect and correct potential outliers, MR-PRESSO analysis was used. Heterogeneity was assessed using Cochrane Q-values. The MR analyses found a possible relationship between T2D and a risk increase of 8 diseases at suggestive level of evidence (P < .05). Notably, among the positive findings that met the false discovery rate threshold, nerve, nerve root, and plexus disorders (odds ratio [OR] = 1.11; 95% confidence interval [CI] = 1.08-1.15); neurological diseases (OR = 1.05; 95% CI = 1.03-1.07) and carpal tunnel syndrome (OR = 1.10; 95% CI = 1.05-1.16) were identified. Our findings affirm a cause-and-effect association between T2D and certain neurological disorders.

Peroneal Nerve Entrapment in Diabetes Mellitus

This narrative mini-review discusses the association between peroneal nerve entrapment (PEN) and diabetes mellitus (DM). Generally, PEN is not a common cause of peripheral neuropathy in DM. Poor glycaemic control and DM duration are powerful risk factors for PEN. Underlying mechanisms involve neurodegeneration and entrapment of the peroneal nerve. Patients tend to present with chronic leg pain, gradual foot drop, steppage gait, or weakness of ankle dorsiflexion. Electrodiagnostic and imaging studies are very useful in diagnosis to determine the level at which entrapment occurs. Treatment varies based on the aetiology and severity of symptoms. It is initially conservative. Surgical nerve decompression management is required when entrapment is refractory to non-operative options.

Presurgical management of ulnar nerve entrapment in patients with and without diabetes mellitus

Diabetes mellitus (DM) is a risk factor for the development of ulnar nerve entrapment (UNE). Differences in surgical outcomes for UNE between patients with and without DM have been reported, but studies on presurgical management are scarce. This study aimed to evaluate the presurgical management of UNE in patients with (DM diagnosis < 2 years of UNE diagnosis) and without DM regarding the level of care for diagnosis and the proportion that proceeds to surgery. Data from 6600 patients with UNE between 2004 and 2019 were included from the Skåne Health Care Register (SHR) and cross-linked with data from the Swedish National Diabetes Register (NDR). The group with UNE and DM was compared to the group with UNE without DM and prevalence ratios were calculated using Cox regression analysis. Patients with DM more often got their first UNE diagnosis in secondary care than in primary care (643/667, 96% vs. 5361/5786; 93%). Patients with and without DM, regardless of the type of DM, presence of retinopathy, or HbA1c levels, were surgically treated for UNE to the same extent (258/667, 39% of patients with DM vs. 2131/5786, 37% of patients without DM). The proportion of surgically treated was significantly lower among patients diagnosed with UNE in primary care compared to secondary care (59/449, 13% vs. 2330/5786, 38%). Men were more often surgically treated than women (1228/3191, 38% vs.1161/3262 36%). Patients with UNE and DM are surgically treated to the same extent as patients with UNE but without DM and are more likely to be diagnosed in specialized care.

Carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is the most common nerve entrapment disorder worldwide. The epidemiology and risk factors, including family burden, for developing CTS are multi-factorial. Despite much research, its intricate pathophysiological mechanism(s) are not fully understood. An underlying subclinical neuropathy may indicate an increased susceptibility to developing CTS. Although surgery is often performed for CTS, clear international guidelines to indicate when to perform non-surgical or surgical treatment, based on stage and severity of CTS, remain to be elucidated. Neurophysiological examination, using electrophysiology or ultrasonography, performed in certain circumstances, should correlate with the history and findings in clinical examination of the person with CTS. History and clinical examination are particularly relevant globally owing to lack of other equipment. Various instruments are used to assess CTS and treatment outcomes as well as the effect of the disorder on quality of life. The surgical treatment options of CTS - open or endoscopic - offer an effective solution to mitigate functional impairments and pain. However, there are risks of post-operative persistent or recurrent symptoms, requiring meticulous diagnostic re-evaluation before any additional surgery. Health-care professionals should have increased awareness about CTS and all its implications. Future considerations of CTS include use of linked national registries to understand risk factors, explore possible screening methods, and evaluate diagnosis and treatment with a broader perspective beyond surgery, including psychological well-being.

Surgery for carpal tunnel syndrome in patients with and without diabetes-Is there a difference in the frequency of surgical procedures?

Carpal tunnel syndrome (CTS) occurs more often among individuals with diabetes. The aim of this retrospective observational registry study was to examine whether individuals with diabetes and CTS are treated surgically to the same extent as individuals with CTS but without diabetes. Data on CTS diagnosis and surgery were collected from the Skåne Healthcare Register (SHR). A total of 35,105 individuals (age ≥ 18 years) diagnosed with CTS from 2004-2019 were included. Data were matched to the Swedish National Diabetes Register (NDR. Cox regression models were used to calculate the risk of the use of surgical treatment. Of the 35,105 included individuals with a CTS diagnosis, 17,662 (50%) were treated surgically, and 4,966 (14%) had diabetes. A higher number of individuals with diabetes were treated surgically (2,935/4,966, 59%) than individuals without diabetes (14,727/30,139, 49%). In the Cox regression model, diabetes remained a significant risk factor for surgical treatment (PR 1.14 (95% CI 1.11-1.17)). Individuals with type 1 diabetes were more frequently treated surgically (490/757, 65%) than individuals with type 2 diabetes (2,445/4,209, 58%). There was no difference between the sexes and their treatment. The duration of diabetes was also a risk factor for surgical treatment in diabetes type 2, but high HbA1c levels were not. Individuals with diabetes are more likely to be treated surgically for CTS than individuals without diabetes. Individuals with type 1 diabetes are more likely to be treated surgically for CTS than individuals with type 2 diabetes.

Incidence of Upper Extremity Neuropathies at a Single Tertiary Care Institution in the United States: Trends in Recent Years, Including the COVID-19 Pandemic

OBJECTIVE

This study examined trends in upper extremity (UE) neuropathies at a large urban tertiary care center in the Northeastern United States over the past five years, including the period of the COVID-19 pandemic.

METHOD

A retrospective medical record review was conducted from 2018 to 2022. We collected data from unique patient records identified using International Classification of Diseases, Tenth Revision (ICD-10) codes for UE neuropathies. We characterized subjects by age, demographics, and duration of symptoms.  Results: This study included 288 pediatric patients and 51,997 adult patients newly diagnosed with UE neuropathy. Most patients were aged 55+; 0.4% of all patients diagnosed with UE neuropathy were children. Across all ages, there was an overall increase in UE neuropathy diagnoses in the past five years, with the most noticeable increases from 2018 to 2019 (+5,761 diagnosed individuals, or +122%) and from 2020 to 2021 (+2,769 diagnosed individuals, or +28.8%).

CONCLUSION

Our institution's UE neuropathy diagnoses have increased in the past five years. Of note, there was a significantly increased rate of UE neuropathy diagnoses from 2020 to 2021. This increase coincides with the COVID-19 pandemic, which is leading to a changing environment for many Americans. These societal changes will likely become indelible after the pandemic; safety practices should be enacted to avoid these debilitating neuropathies.

Khachatryan L, Mohammadian-Hafshejani A. Investigating the association between diabetes and carpal tunnel syndrome: A systematic review and meta-analysis approach

INTRODUCTION

In recent years, several studies have reported on the relationship between diabetes and carpal tunnel syndrome (CTS). However, due to their contradictory results, a systematic review and meta-analysis were conducted to investigate this subject.

METHODS

This study is a systematic review and meta-analysis of studies published in ISI Web of Science, Scopus, PubMed, Cochrane, Google Scholar, and Embase databases. Heterogeneity in the studies included in the meta-analysis was evaluated using statistical tests such as the Chi-square test, I2, and forest plots. Publication bias was assessed using Begg's and Egger's tests.

RESULTS

This investigation analyzed data from 42 studies conducted between 1985 and 2022, with a total of 3,377,816 participants. The meta-analysis demonstrated that the odds ratio (OR) of CTS in participants with a history of diabetes compared to those without was 1.90 (95% CI: 1.64-2.21; P-value < 0.001). Given that publication bias was observed in this study (Begg's test P-value = 0.01), the modified OR was calculated with consideration of missed studies, which was 1.68 (95% CI: 1.45-1.94; P-value < 0.001).

CONCLUSION

The results of this study suggest that diabetic patients have 90% higher odds of developing CTS compared to non-diabetic individuals, which is statistically significant.

The Unpredictable Ulnar Nerve-Ulnar Nerve Entrapment from Anatomical, Pathophysiological, and Biopsychosocial Aspects

Peripheral nerves consist of delicate structures, including a rich microvascular system, that protect and nourish axons and associated Schwann cells. Nerves are sensitive to internal and external trauma, such as compression and stretching. Ulnar nerve entrapment, the second most prevalent nerve entrapment disorder after carpal tunnel syndrome, appears frequently at the elbow. Although often idiopathic, known risk factors, including obesity, smoking, diabetes, and vibration exposure, occur. It exists in all adult ages (mean age 40-50 years), but seldom affects individuals in their adolescence or younger. The patient population is heterogeneous with great co-morbidity, including other nerve entrapment disorders. Typical early symptoms are paresthesia and numbness in the ulnar fingers, followed by decreased sensory function and muscle weakness. Pre- and postoperative neuropathic pain is relatively common, independent of other symptom severity, with a risk for serious consequences. A multimodal treatment strategy is necessary. Mild to moderate symptoms are usually treated conservatively, while surgery is an option when conservative treatment fails or in severe cases. The decision to perform surgery might be difficult, and the outcome is unpredictable with the risk of complications. There is no consensus on the choice of surgical method, but simple decompression is relatively effective with a lower complication rate than transposition.

Serum biomarkers in patients with hand-arm vibration injury and in controls

Hand-arm vibration injury is a well-known occupational disorder that affects many workers globally. The diagnosis is based mainly on quantitative psychophysical tests and medical history. Typical manifestations of hand-arm vibration injury entail episodes of finger blanching, Raynaud's phenomenon (RP) and sensorineural symptoms from affected nerve fibres and mechanoreceptors in the skin. Differences in serum levels of 17 different biomarkers between 92 patients with hand-arm vibration injury and 51 controls were analysed. Patients with hand-arm vibration injury entailing RP and sensorineural manifestations showed elevated levels of biomarkers associated with endothelial injury or dysfunction, inflammation, vaso- or neuroprotective compensatory, or apoptotic mechanisms: intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1); thrombomodulin (TM), heat shock protein 27 (HSP27); von Willebrand factor, calcitonin gene-related peptide (CGRP) and caspase-3. This study adds important knowledge on pathophysiological mechanisms that can contribute to the implementation of a more objective method for diagnosis of hand-arm vibration injury.

Incidence, Prevalence, and Outcomes of Hand Manifestations in Patients With Diabetes Mellitus: A Comprehensive Literature Review

Diabetes mellitus is a metabolic disease that results in long-term hyperglycemia. Among the many long-term complications associated with diabetes, manifestations in the hand include Dupuytren's contracture, trigger finger, compressive neuropathies, and infections. These conditions can have a profound impact on a patient's quality of life, highlighting the importance of timely recognition and treatment of these manifestations. This review aims to provide updated information regarding the incidence and outcomes of these clinical manifestations in the diabetic versus nondiabetic population. A systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was performed. The literature search included the use of PubMed and Ovid databases to find relevant articles that were then selected based on an inclusion criterion that required level 4 evidence. Diabetes mellitus results in an increased incidence of Dupuytren's contracture, trigger finger, carpal tunnel syndrome, cubital tunnel syndrome, and hand infections. Dupuytren's, trigger finger, and carpal tunnel syndrome all had similar outcomes, while diabetic patients had worse outcomes related to infections. There was a lack of data regarding the effect of diabetes on cubital tunnel syndrome. Future studies should be performed to analyze the effects of diabetes mellitus on hand manifestations, particularly regarding the outcomes of diabetic patients with cubital tunnel syndrome.

Carpal tunnel syndrome

Median neuropathy at the wrist, commonly referred to as carpal tunnel syndrome (CTS), is the most common entrapment neuropathy. It is caused by chronic compression of the median nerve at the wrist within the space-limited carpal tunnel. Risk factors that contribute to the etiology of compression include female gender, obesity, work-related factors, and underlying medical conditions, such as hypothyroidism, pregnancy, and amyloidosis. The diagnosis is made on clinical grounds, although these can be confounded by anatomical variations. Electrodiagnostic studies, which are specific and sensitive in diagnosing CTS, support the diagnosis; however, a subgroup may present with normal results. The advent of imaging techniques, including ultrasound and MRI, further assists the diagnostic process. The management of CTS is divided into the nonsurgical approaches that include hand therapy, splinting and corticosteroid injection, and surgical decompression of the carpal tunnel. Although several surgical techniques have been developed, no one method is more effective than the other. Each of these management approaches are effective at providing symptom relief and are utilized at different severities of the condition. There is, however, a lack of consensus on standardized diagnostic criteria, as well as when and to whom to refer patients for surgery.

Occupational and non-occupational risk factors correlating with the severity of clinical manifestations of carpal tunnel syndrome and related work disability among workers who work with a computer

The contribution of certain occupational and personal factors to the development of carpal tunnel syndrome (CTS) is still uncertain. We investigated which specific occupational and non-occupational factors correlate with the level of clinical manifestations and work disability related to CTS. The study included 190 workers who work with a computer and have diagnosed CTS (100 men, 90 women, aged 20-65 years). Subjective experience of CTS-related impairments was assessed with the Symptom Severity Scale (SSS) and the Functional Status Scale (FSS) of the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ). The objective, neural impairments were tested with electrodiagnostics (EDX), whereas CTS-related work disability data were collected from medical records. We found a high inter-correlation between BCTQ, EDX, and work disability data. These also showed high correlations with certain occupational factors (duration of computer-working in months and hours spent daily in computer-working, certain ergonomic, microclimatic, and other occupational conditions) and non-occupational factors (demographic and lifestyle factors: nutritional status, diet, smoking, alcohol consumption, and physical activity). Despite its limitations, our study has identified occupational and non-occupational risk factors that can aggravate CTS and work disability, but which can also be improved with workplace and lifestyle preventive and corrective measures. More research is needed, though, to establish the possible causal relationships and the independent influence of each of those risk factors.

Towards a practical use of text mining approaches in electrodiagnostic data

Healthcare professionals produce abounding textual data in their daily clinical practice. Text mining can yield valuable insights from unstructured data. Extracting insights from multiple information sources is a major challenge in computational medicine. In this study, our objective was to illustrate how combining text mining techniques with statistical methodologies can yield new insights and contribute to the development of neurological and neuromuscular-related health information. We demonstrate how to utilize and derive knowledge from medical text, identify patient groups with similar diagnostic attributes, and examine differences between groups using demographical data and past medical history (PMH). We conducted a retrospective study for all patients who underwent electrodiagnostic (EDX) evaluation in Israel's Sheba Medical Center between May 2016 and February 2022. The data extracted for each patient included demographic data, test results, and unstructured summary reports. We conducted several analyses, including topic modeling that targeted clinical impressions and topic analysis to reveal age- and sex-related differences. The use of suspected clinical condition text enriched the data and generated additional attributes used to find associations between patients' PMH and the emerging diagnosis topics. We identified 6096 abnormal EMG results, of which 58% (n = 3512) were males. Based on the latent Dirichlet allocation algorithm we identified 25 topics that represent different diagnoses. Sex-related differences emerged in 7 topics, 3 male-associated and 4 female-associated. Brachial plexopathy, myasthenia gravis, and NMJ Disorders showed statistically significant age and sex differences. We extracted keywords related to past medical history (n = 37) and tested them for association with the different topics. Several topics revealed a close association with past medical history, for example, length-dependent symmetric axonal polyneuropathy with diabetes mellitus (DM), length-dependent sensory polyneuropathy with chemotherapy treatments and DM, brachial plexopathy with motor vehicle accidents, myasthenia gravis and NMJ disorders with botulin treatments, and amyotrophic lateral sclerosis with swallowing difficulty. Summarizing visualizations were created to easily grasp the results and facilitate focusing on the main insights. In this study, we demonstrate the efficacy of utilizing advanced computational methods in a corpus of textual data to accelerate clinical research. Additionally, using these methods allows for generating clinical insights, which may aid in the development of a decision-making process in real-life clinical practice.

Body mass index and carpal tunnel syndrome: A case-control study

To investigate the electrophysiological characteristics of carpal tunnel syndrome (CTS) and to evaluate the relationship between electrophysiological indexes and body mass index (BMI). In the analysis of 153 hospitalized patients with CTS, the median motor conduction velocity, motor conduction amplitude, motor conduction latency, sensor conduction velocity, sensor conduction amplitude and median sensory latency were analyzed. BMI was calculated. Total 171 healthy individuals were selected as control group. According to Guidelines for Prevention and Control of Overweight and Obesity in Chinese Adults, patients were divided into groups A, B and C. Patients with BMI (kg/m2) <24 were classified into group A; those with 24 ≤ BMI < 28 were regarded as overweight and classified into group B; and those with BMI ≥ 28 were regarded as obese and classified into group C. The BMI of CTS patients was significantly higher than that of healthy individuals (P < .05). For the sensory nerve, with the increase of BMI, the incubation period was gradually prolonged and the conduction velocity gradually decreases (P < .05). In terms of motor latency, with an increase in BMI, the latency showed a trend of first decreasing and then increasing, while the conduction velocity showed a trend of first increasing and then decreasing (P < .05). Electrophysiological examination plays an important supporting role in the diagnosis of CTS. BMI is positively correlated with the degree of CTS injury to a certain extent. Weight loss can effectively prevent the occurrence of CTS and slow the progression of nerve damage in CTS patients.

The role of ultrasound in determining the presence and severity of carpal tunnel syndrome in diabetic patients

Carpal tunnel syndrome (CTS) is seen in 5% of the population and 14%-30% in diabetics. Although electrophysiological tests are used as the gold standard method in the diagnosis, alternative methods are being studying. We aimed to investigate whether the measurement of median nerve cross-sectional area (CSA) by ultrasound is associated with the presence and severity of CTS. This prospective, cross-sectional observational study includes 128 randomly selected T2DM patients. Electrodiagnostic study was performed for all patients to diagnose CTS. Median nerve CSA were measured with ultrasound examination. The severity of the CTS was determined by Padua method. Among 128 diabetes mellitus (DM) patients, 54 (28%) had CTS and 53 (41%) had diabetic peripheral polyneuropathy. The mean duration of DM was 11.55 years. Median nerve CSAs of the patients were significantly higher in patients with CTS (CTS (-): 10.47 ± 2.67 vs CTS: (+) 12.37 ± 3.17; p < 0.001). Median nerve CSA cutoff value of >10 mm2 predicts the diagnosis of CTS. However, minimal, mild, and moderate CTS groups had similar CSA according to Padua classification (p > 0.05 for all). CSA measurement with ultrasonography can be used as an effective method in diagnosing severe CTS disease. However, median nerve CSA values should not be used to reveal the severity of CTS, in order not to miss the demonstration of minimal, mild, and moderate groups, as well as being an indicator of only the severe CTS group.

Risk factors for carpal tunnel syndrome in patients attending the primary care center of a tertiary hospital in Riyadh, Saudi Arabia: A case-control study

BACKGROUND

Carpal tunnel syndrome (CTS), the most common entrapment neuropathy in the upper extremity, is known to be a multi-factorial disease that raises medical and nonmedical risk factors. The aim of the current study was to determine the risk factors of CTS in patients attending the primary care center at a tertiary hospital.

MATERIALS AND METHODS

A case-control study was conducted by reviewing all medical records of patients above the age of 18 years old diagnosed with CTS from 2015 to 2021. The selected cases were evaluated by physical examination and confirmed by a nerve conduction study. Cases and controls were matched by age, gender, and nationality, with a case-to-control ratio of 1:2. Odds ratios were calculated for association between carpel tunnel syndrome and various factors and Chi-sqauare test determined statistical significance. Multiple logistic regression was performed to adjust for confounding.

RESULTS

The study recruited 144 cases with a mean age of 53.38 ± 12.20 years and 288 controls with a mean age of 53.80 ± 12.27 years. The majority of subjects were female (84.7%) and of Saudi nationality (68.3%). There was a significant difference in body mass index, employment status, number of years of employment, occupation, mean systolic blood pressure, mean low-density lipoprotein cholesterol level, and mean blood urea level between cases and controls (P < 0.05). Laboratory tests that were found to be significantly associated with CTS in univariate analysis were thyroid-stimulating hormone (crude odds ratio [COR] = 0.828) and urea level (COR = 0.802). In fully adjusted analyses, obesity (adjusted odds ratio [AOR] =3.080), chronic kidney disease (AOR = 3.629), and the use of corticosteroid (AOR = 0.470) were also significantly associated with CTS.

CONCLUSION

Similar to the findings of other studies, this study identified several potential risk factors for CTS. More large-scale longitudinal studies are required to establish a precise causal association.

High HbA1c Levels Are Associated With Development of Trigger Finger in Type 1 and Type 2 Diabetes: An Observational Register-Based Study From Sweden

OBJECTIVE

Trigger finger (TF) is a hand disorder causing the fingers to painfully lock in flexion. Diabetes is a known risk factor; however, whether strict glycemic control effectively lowers risk of TF is unknown. Our aim was to examine whether high HbA1c was associated with increased risk of TF among individuals with diabetes.

RESEARCH DESIGN AND METHODS

The Swedish National Diabetes Register (NDR) was cross-linked with the health care register of the Region of Skåne in southern Sweden. In total, 9,682 individuals with type 1 diabetes (T1D) and 85,755 individuals with type 2 diabetes (T2D) aged ≥18 years were included from 2004 to 2019. Associations between HbA1c and TF were calculated with sex-stratified, multivariate logistic regression models with 95% CIs, with adjustment for age, duration of diabetes, BMI, and systolic blood pressure.

RESULTS

In total, 486 women and 271 men with T1D and 1,143 women and 1,009 men with T2D were diagnosed with TF. Increased levels of HbA1c were associated with TF among individuals with T1D (women OR 1.26 [95% CI 1.1-1.4], P = 0.001, and men 1.4 [1.2-1.7], P < 0.001) and T2D (women 1.14 [95% CI 1.2-1.2], P < 0.001, and men 1.12 [95% CI 1.0-1.2], P = 0.003).

CONCLUSIONS

Hyperglycemia increases the risk of developing TF among individuals with T1D and T2D. Optimal treatment of diabetes seems to be of importance for prevention of diabetic hand complications such as TF.

Is Smoking Associated with Carpal Tunnel Syndrome? A Meta-Analysis

To date, the role of smoking in carpal tunnel syndrome (CTS) is unclear. The aim of this systematic review and meta-analysis was to assess the association between smoking and CTS. The literature searches were conducted in PubMed, Embase, and Scopus, from inception until October 2021. Three reviewers screened the titles, abstracts, and full-text articles and evaluated the methodological quality of the included studies. A random-effects meta-analysis was used, and heterogeneity across studies was examined using I² statistic. A total of 31 (13 cross-sectional, 10 case-control, and 8 cohort) studies were qualified for meta-analysis. In a meta-analysis of cohort studies, the risk of CTS did not differ between current and never smokers (pooled hazard ratio (HR) 1.09, 95% CI 0.84–1.43), current and past/never smokers (HR 1.07, 95% CI 0.94–1.23), and past and never smokers (HR 1.12, 95% CI 0.83–1.49). Furthermore, a meta-analysis of case control studies found no difference in the risk of CTS between current and never smokers (pooled odds ratio (OR) 0.92, 95% CI 0.56–1.53), current and past/never smokers (OR 1.10, 95% CI 0.51–2.36), and past and never smokers (OR 0.91, 95% CI 0.59–1.39). However, a meta-analysis of cross-sectional studies showed the associations of ever (OR 1.36, 95% CI 1.08–1.72) and current smoking (OR 1.52, 95% CI 1.11–2.09) with CTS. However, the association between ever smoking and CTS disappeared after limiting the meta-analysis to higher quality studies or after adjusting for publication bias. The association between current smoking and CTS also attenuated after limiting the meta-analysis to studies that confirmed CTS by a nerve conduction study or studies with low attrition bias. This meta-analysis does not support an association between smoking and CTS. The association between smoking and CTS observed in cross-sectional studies could be due to biases and/or confounding factors.

Carpal Tunnel Syndrome and Ulnar Nerve Entrapment Are Associated with Impaired Psychological Health in Adults as Appraised by Their Increased Use of Psychotropic Medication

We aimed to study psychological health, as approximated by the use of psychotropic drugs, in a population diagnosed and surgically treated for carpal tunnel syndrome (CTS) or ulnar nerve entrapment (UNE), or both, also considering the demographic and socioeconomic factors of the individuals. Linking data from five large national registers, use of psychotropics (at least one dispensation during the first year after the surgery or the baseline date) was examined in around 5.8 million people 25–80 years old residing in Sweden 2010. Among these individuals, 9728 (0.17%), 890 (0.02%) and 149 (0.00%) were identified as diagnosed and surgically treated for CTS, UNE, or both, respectively. As much as 28%, 34% and 36% in each group, respectively, used psychotropic drugs, compared with 19% in the general population. Regression analyses showed a general higher risk for use of psychotropics related to these nerve compression disorders, to higher age, being a woman, and having low income or low occupational qualification level. Individuals born outside of Sweden had a lower risk. We conclude that surgically treated individuals with a nerve compression disorder have an increased risk of impaired psychological health. Caregivers should be aware of the risk and provide necessary attention.

Electrodiagnostic Testing and Nerve Ultrasound of the Carpal Tunnel in Patients with Type 2 Diabetes

In diabetic patients, controversies still exist about the validity of electrodiagnostic and nerve ultrasound diagnosis for carpal tunnel syndrome (CTS). We analyzed 69 patients with type 2 diabetes. Nerve conduction studies and peripheral nerve ultrasound of the median nerve over the carpal tunnel were performed. CTS symptoms were assessed using the Boston Carpal Tunnel Questionnaire. Polyneuropathy was assessed using the Neuropathy Symptom Score and the Neuropathy Disability Score. Although 19 patients reported predominantly mild CTS symptoms, 37 patients met the electrophysiological diagnosis criteria for CTS, and six patients were classified as severe or extremely severe. The sonographic cross-sectional area (CSA) of the median nerve at the wrist was larger than 12 mm² in 45 patients (65.2%), and the wrist-to-forearm-ratio was larger than 1.4 in 61 patients (88.4%). Receiver operating characteristic analysis showed that neither the distal motor latency, the median nerve CSA, nor the wrist-to-forearm-ratio could distinguish between patients with and without CTS symptoms. Diagnosis of CTS in diabetic patients should primarily be based upon typical clinical symptoms and signs. Results of electrodiagnostic testing and nerve ultrasound have to be interpreted with caution and additional factors have to be considered especially polyneuropathy, but also body mass index and hyperglycemia.

Carpal Tunnel Syndrome and Diabetes—A Comprehensive Review

Carpal tunnel syndrome (CTS) is the most common compression neuropathy in the general population and is frequently encountered among individuals with type 1 and 2 diabetes. The reason(s) why a peripheral nerve trunk in individuals with diabetes is more susceptible to nerve compression is still not completely clarified, but both biochemical and structural changes in the peripheral nerve are probably implicated. In particular, individuals with neuropathy, irrespective of aetiology, have a higher risk of peripheral nerve compression disorders, as reflected among individuals with diabetic neuropathy. Diagnosis of CTS in individuals with diabetes should be carefully evaluated; detailed case history, thorough clinical examination, and electrophysiological examination is recommended. Individuals with diabetes and CTS benefit from surgery to the same extent as otherwise healthy individuals with CTS. In the present review, we describe pathophysiological aspects of the nerve compression disorder CTS in relation to diabetes, current data contributing to the explanation of the increased risk for CTS in individuals with diabetes, as well as diagnostic methods, treatment options, and prognosis of CTS in diabetes.

Preoperative Electrophysiology in Patients With Ulnar Nerve Entrapment at the Elbow-Prediction of Surgical Outcome and Influence of Age, Sex and Diabetes

The impact of preoperative electrophysiology on outcome of surgical treatment in ulnar nerve entrapment at the elbow (UNE) is not clarified. Our aim was to evaluate influence of preoperative electrophysiologic grading on outcome and analyse how age, sex, and in particular diabetes affect such grading. Electrophysiologic protocols for 406 UNE cases, surgically treated at two hand surgery units reporting to the Swedish National Quality Register for Hand Surgery (HAKIR; 2010-2016), were retrospectively assessed, and graded as normal, reduced conduction velocity, conduction block or axonal degeneration. Outcome of surgery after primary and revision surgery was evaluated using QuickDASH and a doctor reported outcome measure (DROM) grading. No differences in QuickDASH or DROM were found between the four groups with different electrophysiologic grading preoperatively, or at three and 12 months or at follow up, respectively. When dichotomizing the electrophysiologic grading into normal and pathologic electrophysiology, cases with normal electrophysiology had worse QuickDASH than cases with pathologic electrophysiology preoperatively (p=0.046). Presence of a conduction block or axonal degeneration indicated a worse outcome by DROM grading (p=0.011). Primary surgeries had electrophysiologic more pronounced nerve pathology compared to revision surgeries (p=0.017). Cases of older age, men, and those with diabetes had more severe electrophysiologic nerve affection (p&lt;0.0001). In the linear regression analysis, increasing age (unstandardized B=0.03, 95% CI 0.02-0.04; p&lt;0.0001) and presence of diabetes (unstandardized B=0.60, 95% CI 0.25-0.95; p=0.001) were associated with a higher risk of a worse electrophysiologic classification. Female sex was associated with a better electrophysiologic grading (unstandardized B=-0.51, 95% CI -0.75- -0.27; p&lt;0.0001). We conclude that older age, male sex, and concomitant diabetes are associated with more severe preoperative electrophysiologic nerve affection. Preoperative electrophysiologic grade of ulnar nerve affection may influence surgical outcome.

Temporal trend of small nerve fibre degeneration in people with and without type 2 diabetes mellitus

AIMS

We investigated the long-term temporal trend of intraepidermal nerve fibre density (IENFD) and the association between changes in IENFD and metabolic factors in individuals with and without type 2 diabetes.

METHODS

A total of 66 participants were enrolled in this longitudinal population-based study, at baseline consisting of 35 individuals (median 61 years) without diabetes and 31 individuals with type 2 diabetes mellitus. Participants underwent clinical and electrophysiological examinations, as well as a skin biopsy both at baseline and at the follow-up visit (mean 8.1 ± 0.5 years). IENFD was assessed in thin sections of 5 μm, stained with the protein gene product 9.5-antibody and compared between the groups.

RESULTS

IENFD decreased during the period in both groups, with a greater decline in the group without diabetes than in type 2 diabetes (-2.3 and -0.6 fibres/mm respectively; p < 0.001). While IENFD at baseline was significantly reduced in type 2 diabetes relative to people without (p < 0.001), no difference in IENFD was found between groups at the follow-up (p = 0.183). Linear mixed model analysis indicated that age, weight and HbA_1c were associated with decrease in IENFD in the total population (p < 0.007). IENFD also decreased with increasing age and weight, but not with HbA_1c , in the separate groups (p < 0.049).

CONCLUSIONS

Despite lower IENFD levels at baseline in type 2 diabetes, IENFD was equal between the groups at follow-up. A decrease in IENFD is to a limited extent affected by body weight, and HbA_1c , but age seems to be the long-term determinant of IENFD in an elderly population.

Identifying Risk Factors for Recurrence After Cubital Tunnel Release

PURPOSE

This study investigated specific risk factors for recurrent surgery of ulnar nerve entrapment (ie, ipsilateral clinical symptoms within 5 years after initial cubital tunnel release [CuTR]) in a large cohort. We hypothesized that recurrence is associated with lifestyle variables (eg, smoking, drinking alcohol, a high body mass index [BMI]) or comorbidities).

METHODS

A retrospective cohort study was performed using the Current Procedural Terminology codes for all patients who underwent CuTR between January 2012 and November 2018. Demographic data, including sex, age, weight, height, BMI, comorbidities, smoking, and alcohol consumption, were collected. The primary outcome was the need for revision surgery after initial CuTR. Univariate and multivariate analyses were performed to identify potential risk factors for revision surgery.

RESULTS

Of the 678 patients who underwent CuTR, 120 patients (18%) needed revision surgery within 5 years. Sixty-six patients required subfascial transposition (55%) and 47 patients (39%) received in situ releases. Also, sex, BMI, smoking, alcohol consumption, and comorbidities (except for spinal disc herniation) were similar between the primary and revision subgroup. Age at first occurrence was significantly lower in the revision group (48 years for revision vs 52 years for primary surgery). Moreover, cervical spinal disc herniation was associated with revision surgery (13% vs 6% in the primary group).

CONCLUSIONS

Age and medical history of cervical spinal disc herniation are associated with an increased risk of revision surgery. More importantly, BMI, smoking, alcohol consumption, and other comorbidities are not associated with increased risk of revision surgery within our sample.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Diabetic hand: prevalence and incidence of diabetic hand problems using data from 1.1 million inhabitants in southern Sweden

INTRODUCTION

'The diabetic hand' has traditionally referred to hand complications due to diabetes mellitus (DM), including trigger finger (TF) and Dupuytren's disease (DD). Recent publications have also proposed DM as a risk factor for carpal tunnel syndrome (CTS), ulnar nerve entrapment (UNE), and possibly osteoarthritis (OA) of the first carpometacarpal (CMC-1) joint. This study aimed to explore prevalence and incidence of diabetic hand complications among the population in southern Sweden.

RESEARCH DESIGN AND METHODS

Approximately 1.1 million inhabitants in the region of Skåne aged ≥18 years, whereof 50 000 with DM, were included. Data on incident CTS, UNE, TF, DD, and OA of the CMC-1 joint between 2004 and 2019 were collected from the Skåne Healthcare Register and cross-linked with the National Diabetes Register. Prevalences on December 31, 2019 and 10-year incidence ratios were calculated for type 1 diabetes (T1D), type 2 diabetes (T2D), and the population without DM, stratified for sex. Prevalence ratios and incidence rate ratios with 95% CIs were used for group comparisons.

RESULTS

The prevalences of all five studied diagnoses were higher in both men and women with T1D and T2D (p<0.01) and both T1D and T2D had more concomitant prevalent diagnoses (p<0.0001). The 10-year incidence rates of all diagnoses were higher among T1D and T2D (p<0.0001), except OA of the CMC-1 joint in men with T1D (p=0.055).

CONCLUSIONS

CTS, UNE, and possibly also OA of the CMC-1 joint should be included together with TF and DD when referring to 'the diabetic hand'. The incidence of hand disorders was up to eight times higher among T1D, and both T1D and T2D had more concomitant prevalent diagnoses compared with the population without DM. Future studies should elucidate the pathophysiology behind diabetic hand complications to enable development of effective preventive measures in patients with diabetes.

Diabetes Mellitus as a Risk Factor for Trigger Finger –a Longitudinal Cohort Study Over More Than 20 Years

Background and Aim

Trigger finger (TF) or stenosing tenosynovitis has been associated with diabetes mellitus (DM), although today’s knowledge is mostly based on cross-sectional and case-control studies. Thus, the aim of the present population-based cohort study over more than 20 years was to investigate DM as a risk factor for TF.

Methods

Data from Malmö Diet and Cancer Study (MDCS), including 30,446 individuals, were analysed with regards to baseline DM and known or potential confounders. Information regarding TF diagnosis until study end date of Dec 31st, 2018, was retrieved from the Swedish National Patient Register (NPR) using ICD-codes. Survival probability was investigated in Kaplan-Meier plots. Cox proportional hazard regression model was used to evaluate DM as risk factor for TF, adjusted for several confounders and presented as Hazard Ratio (HR) with 95% confidence intervals (CI).

Results

At baseline, 4.6% (1,393/30,357) participants had DM. In total, 3.2% (974/30,357) participants were diagnosed with TF during the study period. Kaplan-Meier plot showed that the probability for incident TF was significantly higher in participants with baseline DM compared with individuals without baseline DM. Adjusted HR for DM as risk factor for TF was 2.0 (95% CI: 1.5-2.6, p&lt;0.001).

Conclusion

This longitudinal study showed that DM is an important risk factor for developing TF. When adjusting for sex, age, BMI, manual work, statin use, smoking and alcohol consumption, DM remained the main risk factor for TF.

Injury-Induced HSP27 Expression in Peripheral Nervous Tissue Is Not Associated with Any Alteration in Axonal Outgrowth after Immediate or Delayed Nerve Repair

We investigated injury-induced heat shock protein 27 (HSP27) expression and its association to axonal outgrowth after injury and different nerve repair models in healthy Wistar and diabetic Goto-Kakizaki rats. By immunohistochemistry, expression of HSP27 in sciatic nerves and DRG and axonal outgrowth (neurofilaments) in sciatic nerves were analyzed after no, immediate, and delayed (7-day delay) nerve repairs (7- or 14-day follow-up). An increased HSP27 expression in nerves and in DRG at the uninjured side was associated with diabetes. HSP27 expression in nerves and in DRG increased substantially after the nerve injuries, being higher at the site where axons and Schwann cells interacted. Regression analysis indicated a positive influence of immediate nerve repair compared to an unrepaired injury, but a shortly delayed nerve repair had no impact on axonal outgrowth. Diabetes was associated with a decreased axonal outgrowth. The increased expression of HSP27 in sciatic nerve and DRG did not influence axonal outgrowth. Injured sciatic nerves should appropriately be repaired in healthy and diabetic rats, but a short delay does not influence axonal outgrowth. HSP27 expression in sciatic nerve or DRG, despite an increase after nerve injury with or without a repair, is not associated with any alteration in axonal outgrowth.

Obesity, Type 2 Diabetes, and the Risk of Carpal Tunnel Syndrome: A Two-Sample Mendelian Randomization Study

Some previous observational studies have reported an increased risk of carpal tunnel syndrome (CTS) in patients with obesity or type 2 diabetes (T2D), which was however, not observed in some other studies. In this study we performed a two-sample Mendelian randomization to assess the causal effect of obesity, T2D on the risk of CTS. Single nucleotide polymorphisms associated with the body mass index (BMI) and T2D were extracted from genome-wide association studies. Summary-level results of CTS were available through FinnGen repository. Univariable Mendelian randomization (MR) with inverse-variance-weighted method indicated a positive correlation of BMI with CTS risk [odds ratio (OR) 1.66, 95% confidence interval (CI), 1.39–1.97]. Genetically proxied T2D also significantly increased the risk of CTS [OR 1.17, 95% CI (1.07–1.29)]. The causal effect of BMI and T2D on CTS remained consistent after adjusting for each other with multivariable MR. Our mediation analysis indicated that 34.4% of BMI’s effect of CTS was mediated by T2D. We also assessed the effects of several BMI and glycemic related traits on CTS. Waist circumference and arm fat-free mass were also causally associated with CTS. However, the associations disappeared after adjusting for the effect of BMI. Our findings indicate that obesity and T2D are independent risk factors of CTS.

Metabolic factors and the risk of Dupuytren's disease: data from 30,000 individuals followed for over 20 years

Dupuytren’s disease (DD) is a fibroproliferative disorder affecting the palmar fascia of the hand. Risk factors include diabetes mellitus (DM), whereas a high body mass index (BMI) is associated with a lower prevalence of DD. The aim of this study was to further elucidate risk and protective factors for the development of DD using longitudinal population-based data from the Malmö Diet and Cancer Study (MDCS). During 1991–1996, the inhabitants aged 46–73 years in the city of Malmö, Sweden were invited to participate in the population-based MDCS (41% participation rate). Data on incident DD were retrieved from Swedish national registers. Associations between DM, alcohol consumption, BMI, and serum apolipoprotein A1 (ApoA1) and apolipoprotein B (ApoB) at baseline were analysed in multivariable Cox regression models adjusted for known confounders. Among 30,446 recruited participants, 347 men and 194 women were diagnosed with DD during a median follow-up time of 23 years. DM (men HR 2.23; 95% CI 1.50–3.30, women HR 2.69; 95% CI 1.48–4.90) and alcohol consumption (men HR 2.46; 95% CI 1.85–3.27, women HR 3.56; 95% CI 1.95–6.50) were independently associated with incident DD in the Cox regression models. Furthermore, inverse associations with incident DD were found for obesity among men, and ApoB/ApoA1 ratio among both sexes. DM and excess alcohol consumption constituted major risk factors for the development of DD. Furthermore, an inverse association between obesity among men and DD, and also between ApoB/ApoA1 ratio and DD was found in both sexes.

Rare diabetic neuropathies: It is not only distal symmetrical polyneuropathy

The prevalence of diabetes mellitus is increasing at an epidemic level, leading to a consequent increase of its chronic complications, including neuropathy. Diabetic neuropathy constitutes a heterogeneous group of disorders with distinct clinical presentations and pathophysiological mechanisms. These distinct forms may be categorised according to their clinical presentation as symmetrical (distal symmetrical polyneuropathy, autonomic and acute sensory neuropathy) and focal or multifocal (radiculoplexus neuropathies, entrapment syndromes, cranial palsies and other mononeuropathies). Additionally, people with diabetes may have neuropathies due to causes other than diabetes. The commonest forms of diabetic neuropathy are distal symmetrical polyneuropathy and autonomic neuropathy. However, clinicians should be aware that people with diabetes may suffer from less common forms of neuropathy and should be able to recognise their symptoms and signs. The recognition of the rare diabetic neuropathies is crucial, as they often lead to different clinical outcomes and require different management. The aim of the present narrative, non-systematic review is to outline the rare types of diabetic neuropathies.

Association Between Diabetes Mellitus and Carpal Tunnel Syndrome: Results From the United States National Ambulatory Medical Care Survey

Background

Carpal tunnel syndrome (CTS) is the most common compression neuropathy in the upper limb. While various risk factors have been linked to CTS, the role of diabetes mellitus (DM) in the development of CTS remains unclear. Previous studies have failed to consistently demonstrate a clear association between DM and CTS due to variations based on the geographic setting and differences in the study design. The objective of this study was to assess if there is an association between DM and CTS using population-based data from the United States.

Methodology

We used data from patients ≥18 years old who contributed to the National Ambulatory Medical Care Survey between 2006 and 2015. The outcome was CTS identified by the International Classification of Diseases-9-Clinical Modification codes (354.0 and 354.1), and the main independent variable was physician-reported diabetes status. Multivariable logistic regression was used to adjust for confounding variables. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. Stata v15 was used for all analyses.

Results

Among the patients included in this study (n = 322,092), 13.5% were reported to have diabetes while 0.55% reported CTS. The unadjusted odds of having CTS among patients with diabetes was 0.92 (95% CI: 0.74-1.14; p = 0.447). After adjusting for confounding variables, the association remained not statistically significant (adjusted odds ratio [aOR]: 0.84; 95% CI: 0.65-1.09; p = 0.203). Other variables independently associated with CTS included age 50-59 (aOR: 1.91; 95% CI: 1.49-2.45; p < 0.001), female gender (aOR: 1.31; 95% CI: 1.09-1.58; p < 0.004), and current tobacco users (aOR: 1.32; 95% CI: 1.07-1.63; p < 0.01).

Conclusions

No association was found between DM and CTS in adult ambulatory patients in the United States, but results should be considered in light of potential outcome misclassification.

The prevalence of ulnar neuropathy at the elbow and ulnar nerve dislocation in recreational wheelchair marathon athletes

BACKGROUND

Ulnar neuropathy at the elbow is an entrapment neuropathy, while ulnar nerve dislocation might also be involved in its incidence and severity. Wheelchair marathon athletes may be at an increased risk for Ulnar Neuropathy. However, there is a paucity of research into the prevalence of Ulnar Neuropathy and ulnar nerve dislocation in this population.

OBJECTIVE

To investigate the prevalence of ulnar neuropathy at the elbow and ulnar nerve dislocation in wheelchair marathon athletes.

PARTICIPANTS

Wheelchair marathon athletes (N = 38) who participated in the 2017, 2018, and 2019 Oita International Wheelchair Marathon. 2 athletes participated only one time, 36 athletes repeatedly. Data from athletes`latest assessment were used.

METHODS

The day before the race, questionnaires, physical examinations, and ultrasonography were conducted to screen for Ulnar Neuropathy in both upper limbs. Ulnar nerve dislocation was confirmed by physical examination and ultrasonography.

RESULTS

11 (29%) athletes were diagnosed with Ulnar Neuropathy. There were no significant differences in age, height, weight, Body Mass Index, or history of primary illness between athletes with and without Ulnar Neuropathy. In the group without Ulnar Neuropathy, 44% of athletes reported to have been engaging in other wheelchair sports, compared to 9% in the group with Ulnar Neuropathy (p = 0.037). Ulnar nerve dislocation was diagnosed in 15 (39%) athletes by ultrasonography. Out of the 14 elbows of 11 athletes diagnosed with Ulnar Neuropathy, 9 (64%) elbows had ulnar nerve dislocation.

CONCLUSION

The prevalence of Ulnar Neuropathy in wheelchair marathon athletes was higher than previously reported in able-bodied, non-athlete individuals and lower than in non-athletes with lower limb dysfunction. Therefore, while wheelchair sports may provide some protection against Ulnar Neuropathy, this study further supports the importance of screening for Ulnar Neuropathy, as well as for ulnar nerve dislocation as a potential risk factor for the development of Ulnar Neuropathy.