Carpal Tunnel Syndrome in Diabetes Mellitus

Carpal Tunnel Syndrome and Trigger Finger May Be an Early Symptom of Preclinic Type 2 Diabetes

Background

Type 2 diabetes (T2D) is a major risk factor for carpal tunnel syndrome (CTS) and trigger finger (TF), but less is known regarding the risk of developing T2D after being diagnosed with CTS or TF. CTS and TF could be early signs of preclinical T2D, and early detection of T2D is crucial to prevent complications and morbidity. Therefore, we investigate the association between CTS/TF and T2D in an adult population without previous T2D using big data registers in Sweden.

Methods

Data were collected by crosslinking five nationwide Swedish registers. Individuals aged 40-85 years on December 31, 2010, without prior overt diabetes, were included (n = 3,948,517) and followed up from baseline (ie, a diagnosis of CTS or TF) or January 1, 2011, for controls, until a diagnosis of T2D, prescription of oral antidiabetics or insulin, or end of follow-up four years after baseline. Multivariate Cox regression models were created to calculate hazard ratios for T2D.

Results

In total, 37,346 (0.95%) patients were diagnosed with CTS, whereof 1329 (3.46%) developed T2D. There were 17,432 (0.44%) patients who developed TF, whereof 639 (3.67%) developed T2D. Among the controls, 2.73% developed T2D. Compared with controls, there was an increased risk of developing T2D after being diagnosed with either CTS (HR 1.35; 95% confidence interval 1.28-1.43) or TF (HR 1.21; 95% confidence interval 1.12-1.31).

Conclusion

Compared with controls, a diagnosis of CTS or TF was associated with 35% and 21% higher risk for later T2D, respectively, which might indicate the existence of undetected T2D in this population.

Carpal tunnel syndrome caused by tophi in the superficial flexor tendon: a case report

Carpal tunnel syndrome (CTS) is the most common disease among peripheral nerve entrapment diseases. CTS is often caused by the hyperplasia of the transverse carpal ligament and edema of tissue in the carpal tunnel, resulting in compression of the median nerve. Specific manifestations of CTS include numbness, loss of skin sensation in the palm and three and a half fingers on the radial side, and decreased muscle strength; however, CTS caused by wrist tophi is very rare. To our knowledge, CTS with median nerve compression caused by tophi in the superficial flexor tendon of the index finger of the wrist has not been reported before. Here, we will report a case of CTS caused by tophi in the wrist in a 37-year-old patient with no history of gout. CTS caused by tophi is uncommon, but if the patient has high uric acid, CTS may be due to tophi.

Genetic association of hypertension and several other metabolic disorders with Bell's palsy

Background: Effects of hypertension, type 2 diabetes and obesity on Bell's palsy risk remains unclear. The aim of the study was to explore whether hypertension and these metabolic disorders promoted Bell's palsy at the genetic level. Methods: Genetic variants from genome-wide association studies for hypertension, type 2 diabetes, body mass index and several lipid metabolites were adopted as instrumental variables. Two-sample Mendelian randomization including IVW and MR-Egger was used to measure the genetic relationship between the exposures and Bell's palsy. Sensitivity analyses (i.e., Cochran's Q test, MR-Egger intercept test, "leave-one-SNP-out" analysis and funnel plot) were carried out to assess heterogeneity and horizontal pleiotropy. All statistical analyses were performed using R software. Results: Hypertension was significantly associated with the increased risk of Bell's palsy (IVW: OR = 2.291, 95%CI = 1.025-5.122, p = 0.043; MR-Egger: OR = 16.445, 95%CI = 1.377-196.414, p = 0.029). Increased level of LDL cholesterol might upexpectedly decrease the risk of the disease (IVW: OR = 0.805, 95%CI = 0.649-0.998, p = 0.048; MR-Egger: OR = 0.784, 95%CI = 0.573-1.074, p = 0.132). In addition, type 2 diabetes, body mass index and other lipid metabolites were not related to the risk of Bell's palsy. No heterogeneity and horizontal pleiotropy had been found. Conclusion: Hypertension might be a risk factor for Bell's palsy at the genetic level, and LDL cholesterol might reduce the risk of the disease. These findings (especially for LDL cholesterol) need to be validated by further studies.

Prevalence of carpal tunnel syndrome in patients with long-term type 2 diabetes mellitus

Generally, Carpal tunnel syndrome (CTS) is more common in diabetes mellitus (DM), especially in subjects with coexisting diabetic polyneuropathy (DPN) and/or long-term DM. Based on the analysis of nerve conduction velocity (NCV), the prevalence of CTS and the features of nerve injury were retrospectively explored in type 2 diabetes mellitus (T2DM) patients. In this cohort, there were 353 T2DM patients who were hospitalized in Taiyuan Central Hospitalbetween January 2018 and January 2019. The pathological rates of NCVs between the left and right median nerves were compared, including the gender effect. The examinations were mainly directed to analyze the median nerve injury features. Among 353 patients, 139 patients (39.3%) presented with CTS. These 139 T2DM patients with CTS were then divided into groups based on the nerve injury location and injured nerve type. The prevalence of sensory nerve injury (SNI) was higher than that of motor nerve injury (MNI). The CTS patients had a significantly higher occurrence rate of SNI than MNI (P < 0.05). The abnormal rate of sensory nerve conduction velocity (SCV, P = 0.01) and motor nerve conduction velocity (MCV, P < 0.05) were higher in the right median nerve. No significant differences were detected for other nerves on either side. Significant differences in abnormal rates of SCV of the left (P = 0.04) and the right (P = 0.03) median nerves between the two genders were found. There were no significant abnormalities for other nerves on either side and either gender. Early screening of NCV is needed for T2DM patients to detect CTS with a high prevalence rate. This study suggests that early detection of NCV can identify CTS in the absence of clinical conditions and SNI may occur earlier in long-term T2DM patients with CTS.