Vibration Perception Threshold and Related Factors for Balance Assessment in Patients with Type 2 Diabetes Mellitus

Diabetic peripheral neuropathy (DPN) is a common complication of type 2 diabetes mellitus (DM). DPN causes a decrease in proprioception, which could reduce balance ability. We investigated the association of impaired vibration sense, based on vibration perception threshold (VPT), with assessments of balance and other factors affecting balance impairment and fear of falling in patients with type 2 DM. Sixty-three patients with DM aged >50 years were categorized as having normal vibration sense (NVS; n = 34) or impaired vibration sense (IVS; n = 29) according to a VPT value of 8.9 μm. The following parameters were evaluated for all patients: postural steadiness through the fall index using posturography, functional balance through the Berg Balance Scale (BBS), the Timed Up and Go test (TUG), and fear of falling through the Falls Efficacy Scale-International (FES-I). The IVS group showed a significantly greater balance impairment in fall index, BBS, and TUG, as well as greater fear of falling on the FES-I than the NVS group. The linear regression analysis showed that the fall index was associated only with the VPT, whereas BBS, TUG, and FES-I were associated with the VPT, age, and/or lower extremity muscle strength. VPT, age, and/or muscle strength were identified as predictors of balance and fear of falling in patients with type 2 DM. Therefore, along with age and lower extremity strength, the VPT can be useful for balance assessment in patients with type 2 DM.

A Pilot Study of External Counterpulsation on Reactive Hyperemia, Levels of Glycemia and Metabolic Parameters in Type 2 Diabetes Mellitus

Introduction: External counter-pulsation (ECP) involves cuff inflation over the lower extremities to generate sheer stress, thereby improving endothelial function and anginal symptoms in coronary artery disease. Endothelial dysfunction is also involved in the pathogenesis of T2DM. We hypothesized that 1) ECP will be associated with an improvement in endothelial function in T2DM as measured by peripheral artery tonometry, and 2) explored whether this would vary with different dose and frequency regimens. A shorter or less intensive regimen could potentially reduce cost and improve patient compliance if a similar therapeutic response is achieved. Methods: This single-center prospective study in a tertiary institute in Singapore involving 46 adults with T2DM of HbA1c between 7 to 10%, who were randomly assigned to receive 35 sessions of ECP at different regimens and duration. Subjects in arm 1 received 1-hour daily sessions 5x per week for 7 consecutive weeks, subjects in arm 2 received 0.5-hour sessions 5x per week for 7 consecutive weeks, and subjects in arm 3 received 1-hour sessions 3x per week for 12 consecutive weeks. Endothelial function was evaluated by reactive hyperemia index (RHI) via peripheral arterial tonometry measured at the start, midpoint and end of study. Other secondary outcomes included fasting glucose, homeostatic model assessment of insulin resistance (HOMA-IR), HbA1c, blood pressure, lipid profile, weight and vibration sense. Results: 42 subjects completed the 35-session course of ECP. Mean age was 56.1±9.3 years, duration of diabetes 8.8±4.7 years, baseline RHI 2.0 (1.3–3.7) and baseline HOMA-IR was 3.1 (0.5–18.7). All regimes of ECP were well-tolerated. There was no change in RHI across all 3 regimens of ECP individually or collectively at the end of the study (ΔRHI +0.01%, p=0.458). Glycaemic markers of fasting glucose, HbA1c and HOMA-IR, as well as blood pressure, lipid profile, weight and vibration sense also remained unchanged at endpoint. Subgroup analysis showed a significant improvement in RHI (ΔRHI +20.6%, p=0.0178) in 7 subjects with more severe endothelial dysfunction (defined by RHI<1.67) at baseline who had a trend to having a longer duration of diabetes, however there was no improvement in fasting glucose, HbA1c, HOMA-IR or metabolic parameters in this group. Conclusion: ECP did not show a beneficial effect on endothelial function, glycemic control or metabolic parameters in this South-East Asian population with T2DM at any of the three regimens. This may partly be explained by less severe endothelial dysfunction and less insulin resistance in our population at baseline. Future studies of ECP may investigate its potential benefits in a larger population of T2DM with more severe endothelial dysfunction, higher insulin resistance and/or longer duration of diabetes at baseline.

Proprioception and Clinical Correlation

Proprioception is the sense of position or the motion of the limbs and body in the absence of vision. It is a complex system having both conscious and unconscious components involving peripheral and central pathways. The complexity of sensorimotor systems requires deep knowledge of anatomy and physiology to analyze and localize the symptoms and the signs of the patients. Joint sense and vibration sense examination is an important component of physical examination. This chapter consists anatomy, motor control, postural control related to proprioception with neurologic clinical correlation and also the information about the changes of proprioception after orthopedic surgeries and discuss with the available literature.

Assessment of vibratory QST abnormality in diabetic patients with special correlation to duration of diabetes

Background: Peripheral Neuropathy is one of the common microvascular complications in diabetes mellitus affecting both large and small nerve fibres. In present study we have assessed the impairment of vibration perception threshold (VPT) QST that enables evaluation of affection of large myelinated (Aα and Aβ) fibres. Methods: Authors used Biothesiometer in our study that served a satisfactory tool for quantitating vibratory sense. In our study 120 diabetic patients between 30 to 60 yrs age group with duration of illness ≤10 yrs, 10-20 years and more than 20 years were subjected to Vibratory QST by instrument (Vibrotherm Dx) at several specific points of feet.Results: The result observed is, 73.2% (n=22) diabetics with clinical neuropathy show impairment of vibration sense, while 60% of diabetic patients without clinical neuropathy also show impairment of vibration sense. Result suggests involvement of nerve fibres in a subclinical stage in diabetic patients. Relation between vibratory QST and duration of diabetes is also established, Chi-square trend test is done and it shows there is positive trend with duration of diabetes and it is statistically significant p≤0.001.Conclusions: This study suggests that Vibratory QST should be carried out in every diabetic patient irrespective of clinical neuropathy and duration of diabetes, for early detection, progression & institution of therapy.