Force Generation and Muscle Activation of Knee Extensor and Flexor Muscles in Type 2 Diabetes Mellitus Patients.

Background: Type 2 diabetes mellitus (T2DM) is associated with decreased muscle force generation. The disturbed force generation process in T2DM could be attributed to either or both agonist and antagonist muscles activation. The present study aims to assess the effects of T2DM on the interaction of antagonist and agonist muscles in the knee joint. Methods: The peak torque, root mean square (RMS) of the SEMG signals, the ratio of torque/RMS, and the interaction of antagonists and agonist muscles were compared between healthy and T2DM patients. Surface ElectroMyoGraphy (SEMG) of knee flexor and extensor muscles were recorded during concentric contraction with an isokinetic dynamometer at 60°/s in 13 T2DM and 12 healthy subjects. The independent sample t-tests were used to compare diabetic and healthy subjects. The significance level was set at 0.05. Results: The antagonist/agonist interaction during maximal extension (P = 0.010) and flexion (P = 0.022) torques of the knee joint showed significantly lower activation of antagonist muscles in T2DM patients than in healthy subjects. Lower knee flexion (41.3%) and extension torques (49.1%) and RMS of agonist and antagonist muscles were observed in T2DM. The torque/RMS ratio (P > 0.05) showed no significant differences in T2DM and healthy subjects. Conclusion: The reduced maximal knee flexor and extensor torques in T2DM are accompanied with the decreased myoelectric activity of corresponding muscles. The related mechanism could be attributed to lower values of antagonist/agonist interaction, which may point out some neural compensatory processes to preserve the functional capacity of the neuromuscular system in T2DM.

The effect of aerobic and resistance exercise training on the health related quality of life, physical function, and muscle strength among hemodialysis patients with Type 2 diabetes.

INTRODUCTION: Diabetic patients who undergo hemodialysis commonly suffer from reduction of both exercise capacity and muscle strength. These factors may have a negative effect on health related quality of life (HRQoL) and physical function. We investigated the effect of aerobic and resistance exercise training on the HRQoL, physical function, and muscle strength among hemodialysis patients with Type 2 diabetes. METHODS: Twenty-eight diabetic patients who were on hemodialysis in the Milad Hospital (Tehran, Iran) were recruited for the study. Subjects were randomized into control (n = 13) and exercise training groups (n = 15). The exercise training group performed combined aerobic and resistance exercise training at moderate intensity (11-15/20 on the Borg scale) during hemodialysis treatment, 3 times a week for 8 weeks. The primary outcomes consisted of physical function measured by a 6-min walk test (6MWT), HR-QoL measured by the Short Form Health Survey (SF-36), and lower limb muscle strength measured using a hand-held Digital Dynamometer. RESULTS: The 6MWT distance increased significantly in the exercise training group (36%). Bilateral hip flexor strength (right, 24.5%; left, 30.4%) and abductor strength (right, 27.6%; left, 25.2%) decreased significantly in the non-exercising control group but no significant change was found in the exercise group (P > 0.05). There were no significant changes in any of the 8 generic subscales of HR-QoL neither in the exercise training group nor controls following an 8- week study. CONCLUSIONS: 8 weeks of combined aerobic-resistance exercise training among diabetic hemodialysis patients seem to be effective in improvement of physical function and lower limb muscle strength.

The effects of phase III cardiac rehabilitation in serum and salivary Hs-CRP and anthropometric measurements in patients with coronary artery disease.

AIM: Cardiac rehabilitation is a key part in the treatment of coronary artery disease (CAD) by its anti-infammatory effects. However, the effect of exercise training programs on salivary concentrations of high-sensitivity C-reactive protein (hs-CRP) in patients with coronary artery disease has not been well studied. The objective of this study was to evaluate the effect of phase III cardiac rehabilitation on serum and salivary levels of hs-CRP, in relation to the anthropometric measurements of obesity and the relationship between salivary and serum levels of hs-CRP in CAD male patients. MATERIALS AND METHODS: Forty male volunteers (45-75 years) with CAD participated in 6 to 8 weeks of moderate intensity aerobic exercise training consisting of 45 minutes sessions of treadmill, stationary bicycle and arm ergometer. Anthropometric measurements of obesity, serum level of hs-CRP, stimulated and nonstimulated salivary level of hs-CRP were measured at the beginning, in the middle and at the end of exercise sessions. RESULTS: All anthropometric measurements increased (p < 0.05) following cardiac rehabilitation except waist-hip ratio. Serum hs-CRP level reduced by 36% independent to the anthropometric measurements changes. Stimulated and nonstimulated salivary hs-CRP level decreased 68 and 54%, respectively, after 24 sessions of cardiac rehabilitation. Nonstimulated salivary hs-CRP levels correlated to serum levels of hs-CRP at baseline and after 24 sessions (p < 0.05). CONCLUSION: Phase III cardiac rehabilitation seems to be effective to improve serum and salivary hs-CRP concentrations independent of anthropometric measurements. CLINICAL SIGNIFICANCE: Nonstimulated salivary hs-CRP measurement could be a surrogate for blood measurement of hs-CRP during cardiac rehabilitation in male patients with CAD.