Lower Visceral Fat Area in Patients with Type 2 Diabetic Peripheral Neuropathy.

Objective: There is preliminary evidence that visceral fat area (VFA) was associated with the presence of type 2 diabetic peripheral neuropathy (DPN) in the Korean population; however, no studies have reported the association in Chinese population. The purpose of this study was to explore the possible correlation of VFA with DPN in such a population. Methods: A total of 2498 hospitalized patients with type 2 diabetes mellitus (T2DM) undergone VFA measurement, and were divided into DPN group (n=900) and non-DPN group (n=1594). The association of VFA with the presence of DPN was evaluated by correlation and multiple logistic regression analyses, generalized additive model with a smooth curve fitting, and receiver operating characteristic (ROC) curve analysis. Results: The VFA was significantly lower in the DPN group than in the non-DPN group (P < 0.001). VFA was significantly and positively associated with sural nerve conduction velocity (SNCV) and amplitude potential (SNAP) and negatively associated with the presence of DPN (all P< 0.001); there was no significant difference in the curve fitting (P = 0.344). Multivariate logistic regression analysis showed that the risk of presence of DPN decreased progressively across the VFA quartiles (P for trend < 0.001) and was significantly lower in patients in the highest VFA quartile than in those in the lowest quartile (OR: 0.382, 95% CI 0.151-0.968, P< 0.001) after multivariate adjustment. The ROC analysis revealed that the best cut-off value of VFA for predicting the presence of DPN was 50.5cm2 (sensitivity 84.40%; specificity 34.00%). Conclusion: These results suggest that lower VFA level may be associated with increased risk of the presence of DPN in T2DM patients.

Feasibility of assessing progression of transthyretin amyloid polyneuropathy using nerve conduction studies: Findings from the Transthyretin Amyloidosis Outcomes Survey (THAOS).

Patients with transthyretin amyloid polyneuropathy (ATTR-PN) show decreased motor and sensory nerve amplitudes and conduction. Electrophysiological changes over time may be sensitive indicators of progression. This analysis from the Transthyretin Amyloidosis Outcomes Survey (THAOS) assessed longitudinal changes in nerve conduction as signals of neurologic disease progression in patients with hereditary ATTR (ATTRv) amyloidosis. Patients with ATTRv in THAOS with recorded nerve conduction values were included (data cut-off: January 6, 2020); changes in nerve amplitude and velocity over time were assessed. Patients (n = 1389) were 45.0% male; 80.4% were the Val30Met (p.Val50Met) genotype. Mean (SD) age at enrollment was 43.6 (14.5) years; duration of symptoms was 9.3 (6.4) years. Median (10th, 90th percentile) sural nerve amplitude and velocity was 18.0 (4.9, 35.0) µV and 50.7 (41.0, 57.9) m/s; peroneal conduction was 13.0 (4.4, 27.0) µV and 51.0 (41.7, 59.7) m/s, respectively. Median (10th, 90th percentile) percentage change from baseline in sural nerve amplitude was variable, but generally decreased over time from -7.4 (-43.2, 52.4) at year 1 to -14.4 (-76.9, 46.7) at year 8. Percent change from baseline in sural nerve velocity declined similarly: -0.1 (-14.5, 15.3) at year 1 and - 6.4 (-21.3, 10.5) at year 8. The decline was more pronounced in patients with greater disability at baseline. Similar patterns were observed for the peroneal nerve. These data show an association between nerve amplitudes and velocities and disease severity, suggesting progressive deterioration in nerve conduction may be an indicator of ATTRv amyloidosis disease progression.

Prevalence of Diabetic Neuropathy in Young Adults with Type 1 Diabetes and the Association with Insulin Pump Therapy.

AIMS: The aim was to investigate the prevalence of diabetic sensorimotor polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN) in a Danish population of young adults with type 1 diabetes (T1D) using both established and novel measuring modalities. Furthermore, to investigate the association between continuous subcutaneous insulin infusion (CSII) treatment and these complications. MATERIALS AND METHODS: CAN was assessed by cardiovascular autonomic reflex tests. DSPN was assessed not only by perception of light touch and pain, vibration perception threshold (VPT), Brief Pain Inventory (BPI), and Michigan Neuropathy Screening Instrument questionnaires but also by novel modalities: electrochemical skin conductance (ESC), sural nerve conduction velocity (SNCV), and sural nerve amplitude potential (SNAP). RESULTS: The study comprised 156 young adults with a mean age of 22 years (standard deviation 1.6). The prevalence of CAN and early CAN was 9% and 28.1%, respectively. Subclinical DSPN was 55.1% and confirmed DSPN was 2.6%. Prevalence of abnormal SNAP was 23.8%, SNCV was 37.1%, ESC on the hands and feet was 4% and 8%, respectively, VPT was 1.3%, and BPI questionnaire was 1.9%. No association was found between CSII treatment and the measures of DSPN and CAN. CONCLUSION: DSPN and CAN are prevalent in young adults with T1D with no association found with CSII treatment. The use of novel measuring modalities identified a higher number of subjects with DSPN compared with established measures. Screening for diabetic neuropathy in young adults may be beneficial to detect and prevent nerve damages at early stages.

Medial plantar-to-radial amplitude ratio: does it have electrodiagnostic utility in distal sensory polyneuropathy?

PURPOSE OF THE STUDY: We proposed a new electrophysiological parameter medial plantar (MP)-to-radial amplitude ratio (MPRAR), similar to sural-to-radial amplitude ratio (SRAR), in the diagnosis of distal sensory polyneuropathy (DSP), based on the concept that distal nerves are affected more and earlier than proximal nerves in axonal neuropathies. We aimed to investigate the diagnostic sensitivity of this parameter in diabetic DSP, together with sensitivities of SRAR and MP nerve action potential (NAP) amplitude. MATERIALS AND METHODS: In 124 healthy controls and 87 diabetic patients with clinically defined DSP and normal sural responses, we prospectively performed sensory nerve conduction studies (NCS), and evaluated the MP NAP amplitude, MPRAR and SRAR values. We determined the lower limits of normal (LLN) of these parameters in the healthy controls and calculated their sensitivities and specificities in detecting DSP in diabetic patients. RESULTS: MP nerve amplitude and MPRAR values were significantly lower in the patient group, compared to controls. However, SRAR values did not differ significantly between the two groups. The LLN of MP NAP amplitude was found to be 4.1 µV. The cutoff values for SRAR and MPRAR were determined as 0.24 and 0.16, respectively. MPRAR was abnormal in 21.8% of patients. However, the most sensitive parameter in detection of DSP was MP NAP amplitude, which showed a sensitivity of 31% and a specificity of 100%. CONCLUSIONS: Although MPRAR is more sensitive than SRAR in detecting DSP, it does not provide additional diagnostic yield to the assessment of MP NCS alone in diabetic DSP patients with normal sural responses.

Clinical Significance of Amplitude in Pudendal Nerve Conduction Study in Patients with Defecation Disorders

Many different kinds of anorectal physiologic studies were performed for the evaluation of defecation disorders. Some of these studies are anorectal manometry and pudendal nerve conduction study. In pudendal nerve conduction study, pudendal nerve terminal motor latency (PNTML) was considered to be very useful for the evaluation and management of these patients. However, evaluation of amplitude in pudendal nerve conduction study has been clinically seldom used. Therefore, the aim of this study was to evaluate the clinical significane of amplitude in pudendal nerve conduction study in patients with defecation disorders by comparing to manometric profiles. MATERIAL AND METHODS: Between February, 1997 and February, 1998 all patients who underwent pudendal nerve conduction study and anorectal manometry for the evaluation of defecation disorders (constipation and fecalincontinence) were analyzed. Latency as well as amplitude in pudendal nerve conduction study were compared in both groups to the pressure profiles in manometric study according to the subgroups of these patients. Statistical analysis were performed by a Chi-square or Student's t-test and significance was assumed when p<0.05. RESULTS: A total of 80 patients, forty constipation with a mean age of 55.3+/-14.5 (GI: range; 24~86) years and forty fecal incontinence with a mean age of 61.1+/-10.3 (GII: range; 37~74) years and a male to female ratio of 25:15 (GI), 28:12 (GII), were studied. PNTML in both sides in GI were significantly decreased in comparision to those of GII (GI: Rt, 2.17+/-0.7 ms Lt, 2.03+/-0.5 ms, GII: Rt, 2.50+/-0.7 ms, Lt 2.64+/-0.8 ms, p<0.05), However, there were no differences between the two groups in terms of amplitudes (GI: Rt 399.0+/-348 uV, Lt 426.8+/-403 uV, GII: Rt, 406.9+/-273 uV Lt, 392.9+/-291 uV, NS) in pudendal nerve conduction study. In manometric findings, even though maximal resting, mean, minimum and maximal pushing pressures were no differences in both groups, mean resting and maximal squeezing pressure were significantly increased in GI than those of GII (GI: 82.4+/-31 cmH20, GII: 60.5+/-25 cmH20 in mean resting pressure, GI: 213.1+/-108 cmH20, GII: 178.7+/-66 cmH20 in maximal squeezing pressure, p<0.05) When we analyzed the overall values of amplitudes according to the diagnosis, age, gender, and the value of PNTML, there were no statistically significant differences between the two groups. But, when the one side of PNTML shorter than the other side, it tended to have a high amplitude in that side than that of the other side in the same patient (the probability for trend was 74%). CONCLUSION: Constipation patient has a shorter PNTML, higher mean resting, and maximal squeezing pressure than fecal incontinene patient. The amplitude in pudendal nerve conduction study had a trend of inverse correlation to the latency in the same patient. Therefore, amplitude in pudendal nerve conduction study might be useful to monitor or predict the outcome after treatment in patients with defecation disorders.