Vertical displacement of the centre of mass during walking in people with diabetes and diabetic neuropathy does not explain their higher metabolic cost of walking.

People with diabetes display biomechanical gait alterations compared to controls and have a higher metabolic cost of walking (CoW), but it remains unknown whether differences in the vertical displacement of the body centre of mass (CoM) may play a role in this higher CoW. The aim of this study was to investigate vertical CoM displacement (and step length as a potential underpinning factor) as an explanatory factor in the previously observed increased CoW with diabetes. Thirty-one non-diabetic controls (Ctrl); 22 diabetic patients without peripheral neuropathy (DM) and 14 patients with moderate/severe Diabetic Peripheral Neuropathy (DPN), underwent gait analysis using a motion analysis system and force plates while walking at a range of matched speeds between 0.6 and 1.6 m/s. Vertical displacement of the CoM was measured over the gait cycle, and was not different in either diabetes patients with or without diabetic peripheral neuropathy compared to controls across the range of matched walking speeds examined (at 1 m/s: Ctrl: 5.59 (SD: 1.6), DM: 5.41 (1.63), DPN: 4.91 (1.66) cm; p > 0.05). The DPN group displayed significantly shorter steps (at 1 m/s: Ctrl: 69, DM: 67, DPN: 64 cm; p > 0.05) and higher cadence (at 1 m/s: Ctrl: 117 (SD1.12), DM: 119 (1.08), DPN: 122 (1.25) steps per minute; p > 0.05) across all walking speeds compared to controls. The vertical CoM displacement is therefore unlikely to be a factor in itself that contributes towards the higher CoW observed recently in people with diabetic neuropathy. The higher CoW in patients with diabetes may not be explained by the CoM displacement, but rather may be more related to shorter step lengths, increased cadence and the associated increased internal work and higher muscle forces developed by walking with more flexed joints.

Screening of cardiovascular autonomic neuropathy in patients with diabetes using non-invasive quick and simple assessment of sudomotor function.

AIM: Cardiovascular autonomic neuropathy (CAN) is a common but often overlooked complication of diabetes. Sympathetic C-fibers innervating sweat glands can be impaired early on in patients with diabetes. In this study, SUDOSCAN, a new non-invasive device that assesses sudomotor function was compared to methods generally used for the investigation of CAN. PATIENTS: A total of 232 patients with diabetes were measured for heart rate variability (HRV) at rest and during moderate activity. Time and frequency domain analysis techniques, including measurement of the low-frequency (LF) domain component, were assessed during HRV testing. Ewing tests, as recommended by the French Health Authority, were also done. Electrochemical sweat conductance (ESC) was measured on the hands and feet, and a risk-score was calculated. RESULTS: Using two abnormal Ewing tests as a reference for the area under the curve (AUC) of the receiver operating characteristics (ROC) curve for SUDOSCAN, the risk-score was 0.74, with a sensitivity of 92% and specificity of 49% for a risk-score cut-off value of 35%. For the ROC curve analysis using the LF power component during moderate activity at a threshold of 90 ms(2) (first quartile) as reference, the AUC was higher for the SUDOSCAN risk-score (0.77) compared with the standard Ewing tests [E:I ratio (0.62), 30:15 ratio (0.76) and blood pressure change on standing (0.55)]. Using a cut-off value of 35%, risk-score sensitivity and specificity were 88 and 54%, respectively. CONCLUSION: SUDOSCAN, which allows quick quantitative assessment of sudomotor function, may be used for early screening of CAN in everyday clinical practice before resorting to the more sophisticated and specific, but ultimately more time-consuming, Ewing tests.

Diabetes-induced erectile dysfunction: epidemiology, pathophysiology and management.

Erectile dysfunction (ED) is defined as the inability of the male to attain and maintain erection of penis sufficient to permit satisfactory sexual intercourse. Prevalence of impotence in diabetic men is ≥50%. The pathophysiology of diabetes-induced erectile dysfunction (DIED) is multifactorial and no single etiology is at the forefront. The proposed mechanisms of erectile dysfunction in diabetic patients includes elevated advanced glycation end-products, increased levels of oxygen free radicals, impaired nitric oxide synthesis, increased endothelin B receptor binding sites and up-regulated RhoA/Rho-kinase pathway, neuropathic damage and impaired cyclic guanosine monophosphate (cGMP)-dependent protein kinase-1. The treatment of DIED is multimodal. Treatment of the underlying hyperglycemia and comorbidities is of utmost importance to prevent or halt the progression of disease. Oral medications are considered as the first line therapy for management of DIED. If oral agents cannot be used or have insufficient efficacy despite appropriate dosing and education, second-line treatments should be addressed. When there is lack of efficacy or when there is dissatisfaction with other modalities, penile prostheses are often the best alternative for ED and are considered as the third line therapy for DIED. Future strategies in the evolution of the treatment of DIED are aimed at correcting or treating the underlying mechanisms of DIED.

Cost-effectiveness of duloxetine versus routine treatment for U.S. patients with diabetic peripheral neuropathic pain.

UNLABELLED: The purpose of this study was to compare the cost-effectiveness of duloxetine versus routine treatment in management of diabetic peripheral neuropathic pain (DPNP). Two hundred thirty-three patients with DPNP who completed a 12-week, double-blind, placebo-controlled, randomized, multicenter duloxetine trial were re-randomized into a 52-week, open-label trial of duloxetine 60 mg twice daily versus routine treatment. Routine treatment included pain management therapies. Effectiveness was measured by using the bodily pain domain (BP) of the Medical Outcomes Study Short Form 36 (SF-36). Costs were analyzed from 3 perspectives: third party payer (direct medical costs), employer (direct and indirect medical costs), and societal (patient's out-of-pocket costs and total medical costs). Costs of study medications were not included because of limited data. Bootstrap method was applied to calculate statistical inference of the incremental cost-effectiveness ratio (ICER). Routine treatment most frequently used included gabapentin (56%), venlafaxine (36%), and amitripytline (15%). From employer and societal perspectives, duloxetine was cost-effective (ICER= -342 dollars and -429 dollars, respectively, per unit of SF-36 BP; both P

A quantitative method for the assessment of intraepidermal nerve fibers in small-fiber neuropathy.

OBJECTIVES: The purpose of this paper is to present an easy-to-use and reproducible morphometrical method of determining the density of intraepidermal nerve fibers (IENF) per epidermal area with the corresponding reference range of the IENF-counts. METHODS: Thirty patients and 22 controls were included in this study. The patients were divided into three groups: small-fiber (SFN), diabetic and demyelinating neuropathy. All subjects underwent punch skin biopsy. Specimens were fixed routinely in formalin and thereafter embedded in paraffin. Nerve fibers were revealed using immunoperoxidase staining with panaxonal antibody PGP 9.5. Using light microscopy, immunopositive nerves were counted morphometrically per epidermal area (NPEA) and, for comparison, per epidermal length (NPEL). RESULTS: Both the NPEA and NPEL estimates of SFN and diabetic neuropathy group differed significantly from those of control specimen (p < 0.001 and p < 0.001, Mann-Whitney test). Our method of counting, NPEA, shows a good correlation to NPEL (r = 0.945). CONCLUSIONS: IENF-counting by a new morphometric modification is reproducible and diagnostically sensitive and can easily be adopted in any laboratory familiar with the basic immunohistochemical methodology. The method is less dependent on costly technical support systems and seems to be less time consuming when compared with conventional methods for IENF-counting.

Early increase precedes a depletion of VIP and PGP-9.5 in the skin of insulin-dependent diabetics--correlation between quantitative immunohistochemistry and clinical assessment of peripheral neuropathy.

Diabetic neuropathy affects both sensory and autonomic peripheral nerve fibres. Vasoactive intestinal polypeptide (VIP) is present in autonomic fibres which modulate sweat secretion, while calcitonin gene-related peptide (CGRP) is localized to cutaneous sensory fibres. In this study, immunohistochemistry and image analysis were used to assess changes of VIP and CGRP, and of the pan-neuronal marker protein gene-product (PGP)-9.5, in skin biopsies of 18 patients affected by type 1 diabetes (age range 18-46 years) and from seven aged-matched controls. Patients were divided into three groups: group 1 (n = 6), with diabetes for 6 months to 3 years; group 2 (n = 5), with the disease for 5-10 years; and group 3 (n = 7), with diabetes for more than 10 years. VIP immunoreactivity (IR) and PGP-9.5-IR were significantly reduced around sweat glands (P < 0.005) in groups 2 and 3. Epidermal CGRP-IR and PGP-9.5-IR were significantly reduced in group 3 (P < 0.05). Twenty-eight per cent (5/18) of all patients showed high VIP-IR around sweat glands (> 95 per cent confidence limits of controls) and all of these patients had diabetes for less than 3 years. Conversely, 55 per cent (10/18) of patients had low VIP-IR (< 5 per cent confidence limit of controls). The latter, compared with the former, showed a significantly longer duration of diabetes (Fisher exact test P = 0.002), presence of clinical autonomic neuropathy (Fisher exact test P = 0.04), and a reduced sural nerve conduction velocity (Fisher exact test P = 0.04). These results suggest that quantitative immunohistochemical analysis of peptide-containing cutaneous nerves allows an objective evaluation of nerve fibre alterations at early stages of diabetes than is currently possible with neurophysiological functional tests.

Clinical application of hair protein glycation in the assessment of blood glucose control and diabetic neuropathy.

Glycation of hair protein was assessed in diabetic patients by the measurement of furosine, which is derived from fructose-lysine, a glycated lysine residue in protein. The level of furosine in 12-cm-long hair which grew over the course of one year was significantly better correlated with the mean values of four determinations of fasting plasma glucose (FPG) and four determinations of hemoglobin A1c, respectively, at the time of hair sampling. The level of glycation in hair, which corresponds to the time taken for hair growth, may represent the mean level of blood glucose during the time corresponding to the growth period. The values of motor nerve conduction velocity and sensory nerve conduction velocity were better correlated with the level of furosine in hair corresponding in the length to 1 year's growth than the levels of FPG and hemoglobin A1c at the time of the determination of nerve conduction velocity. These results suggest that hair glycation may serve as a valuable indicator both of long-term blood glucose trends and of the relationship between diabetic complications and blood glucose.