One-year unsupervised individualized exercise training intervention enhances cardiorespiratory fitness but not muscle deoxygenation or glycemic control in adults with type 1 diabetes.
Appl Physiol Nutr Metab. 2017 Nov 20;:
Authors: Rissanen AE, Tikkanen HO, Koponen AS, Aho JM, Peltonen JE
Adaptations to long-term exercise training in type 1 diabetes are sparsely studied. We examined the effects of a 1-year individualized training intervention on cardiorespiratory fitness, exercise-induced active muscle deoxygenation, and glycemic control in adults with and without type 1 diabetes. Eight men with type 1 diabetes (T1D) and eight healthy men (CON) matched for age, anthropometry, and peak pulmonary O2 uptake (V̇O2peak), completed a 1-year individualized training intervention in an unsupervised real-world setting. Before and after the intervention, the subjects performed a maximal incremental cycling test, during which alveolar gas exchange (volume turbine and mass spectrometry) and relative concentration changes in active leg muscle deoxygenated (∆[HHb]) and total (∆[tHb]) hemoglobin (near-infrared spectroscopy) were monitored. Peak O2 pulse, reflecting peak stroke volume, was calculated (V̇O2peak/peak heart rate). Glycemic control (glycosylated hemoglobin A1c [HbA1c]) was evaluated. Both T1D and CON averagely performed one resistance- and 3-4 endurance training sessions per week (~1 h/session at ~moderate intensity). Training increased V̇O2peak in T1D (p=0.004) and CON (p=0.045) (Group×Time p=0.677). Peak O2 pulse also rose in T1D (p=0.032) and CON (p=0.018) (Group×Time p=0.880). Training increased leg ∆[HHb] at peak exercise in CON (p=0.039) but not in T1D (Group×Time p=0.052), while no changes in leg ∆[tHb] at any work rate were observed in either group (p>0.05). HbA1c retained unchanged in T1D (from 58±10 to 59±11 mmol/mol, p=0.609). In conclusion, one-year adherence to exercise training enhanced cardiorespiratory fitness similarly in T1D and CON but had no effect on active muscle deoxygenation or glycemic control in T1D.
PMID: 29156141 [PubMed - as supplied by publisher]
Muscle wasting and sarcopenia in heart failure and beyond: update 2017.
ESC Heart Fail. 2017 Nov;4(4):492-498
Authors: Springer J, Springer JI, Anker SD
Sarcopenia (loss of muscle mass and muscle function) is a strong predictor of frailty, disability and mortality in older persons and may also occur in obese subjects. The prevalence of sarcopenia is increased in patients suffering from chronic heart failure. However, there are currently few therapy options. The main intervention is resistance exercise, either alone or in combination with nutritional support, which seems to enhance the beneficial effects of training. Also, testosterone has been shown to increased muscle power and function; however, a possible limitation is the side effects of testosterone. Other investigational drugs include selective androgen receptor modulators, growth hormone, IGF-1, compounds targeting myostatin signaling, which have their own set of side effects. There are abundant prospective targets for improving muscle function in the elderly with or without chronic heart failure, and the continuing development of new treatment strategies and compounds for sarcopenia and cardiac cachexia makes this field an exciting one.
PMID: 29154428 [PubMed - in process]
Exercise dynamic stability under unstable conditions increases muscle strength and balance ability in the elderly.
Scand J Med Sci Sports. 2017 Nov 20;:
Authors: Hamed A, Bohm S, Mersmann F, Arampatzis A
The purpose of the current study was to assess the effectiveness of a specific exercise intervention of mechanisms to control dynamic postural stability under unstable conditions in old adults. Forty-seven old adults (65-80 years) were assigned to two experimental groups (muscle strength group, n=15, perturbation-based group, n=16) and a control group (n=16). The strength group performed resistance exercises for legs and trunk muscles, while the perturbation-based group exercised mechanisms of dynamic stability under unstable conditions. The training duration was 14 weeks, with training sessions twice a week for 1.5 h. Muscle strength, balance ability and balance recovery performance were investigated before and after the interventions using maximal isometric plantar flexion and knee extension contractions, the approach of the center of pressure to the anterior limits of stability and simulated forward falls. Both interventions increased balance recovery performance in simulated forward falls (81%, d=1.50 and 80% d=1.08 in the muscle strength and perturbation-based group, respectively), while the control group did not show any changes. Plantar flexor strength increased 20% (d= 0.72) in the muscle strength and 23% (d=1.03) in the perturbation-based group, while muscle strength of the knee extensors increased only in the muscle strength group (8%, d=0.76). On the other hand, only the perturbation-based group showed a significant improvement (38%, d=1.61) of standing balance ability. We conclude that a perturbation-based training program focusing on exercising mechanisms of dynamic stability on unstable conditions has the potential to enhance muscle strength as well as sensory information processing within the motor system during sudden and static balance tasks and, as a consequence, reduce the risk of falls in old adults. This article is protected by copyright. All rights reserved.
PMID: 29154407 [PubMed - as supplied by publisher]
Trimetazidine restores the positive adaptation to exercise training by mitigating statin-induced skeletal muscle injury.
J Cachexia Sarcopenia Muscle. 2017 Nov 19;:
Authors: Song M, Chen FF, Li YH, Zhang L, Wang F, Qin RR, Wang ZH, Zhong M, Tang MX, Zhang W, Han L
BACKGROUND: Exercise rehabilitation is demonstrated to improve the prognosis of patients with coronary heart disease (CHD). Statins, as the key medicine to lower cholesterol in CHD, result in skeletal muscle injury and impair exercise training adaptation. Energy metabolism dysfunction is identified as the potential mechanism underlying statin-induced skeletal muscle injury. In this study, we investigated the effects of the metabolic modulator trimetazidine on skeletal muscle energy metabolism and statin-associated exercise intolerance.
METHODS: High-fat fed apolipoprotein E knockout (ApoE(-/-) ) mice were given aerobic exercise and administrated simvastatin, trimetazidine, or simvastatin plus trimetazidine by gavage. Exercise capacity was evaluated at the end of the treatment by hanging grid test, forelimb grip strength, and running tolerance test. Plasma glucose, lipid, and creatine kinase concentrations were measured at the end of the treatment. After sacrifice, gastrocnemii were stored for assessment of muscle morphology and fibre type. Energy metabolism was estimated by plasma lactic acid concentration, ragged red fibres, and glycogen stores. Activities of mitochondrial complex III, citrate synthase activity, and membrane potential were measured to assess mitochondrial function. Oxidative stress was also evaluated by superoxide in mitochondria, superoxide dismutase activity, and glutathione redox state.
RESULTS: In high-fat fed ApoE(-/-) mice, exercise training had no effect on lipid concentrations. Lower lipid concentrations with increased creatine kinase were observed with additional simvastatin treatment. Exercise capacity increased significantly in response to exercise training alone but was blunted by the addition of simvastatin. Similarly, cross-sectional area of muscle fibres and the proportion of slow-twitch fibres increased in the exercise group but decreased in the simvastatin plus exercise group. Additionally, simvastatin increased centronucleated fibres and induced energy metabolism dysfunction by inhibiting complex III activity and thus promoted oxidative stress in gastrocnemius. We demonstrated that trimetazidine could reverse simvastatin-induced exercise intolerance and muscle damages. We also found the ability of trimetazidine in restoration of muscle fibre hypertrophy and facilitating fast-to-slow type shift. The energy metabolism dysfunction and oxidative stress in gastrocnemii were rescued by trimetazidine.
CONCLUSIONS: Trimetazidine alleviated statin-related skeletal muscle injury by restoration of oxidative phenotype and increasing fibre cross-sectional areas in response to exercise training. Correspondingly, the exercise training adaptation were improved in high-fat fed ApoE(-/-) mice. Moreover, trimetazidine is able to exert its positive effects without affecting the beneficial lipid-lowering properties of the statins. Thus, trimetazidine could be prescribed to remedy the undesirable statins-induced exercise intolerance during cardiac rehabilitation in patients with CHD.
PMID: 29152896 [PubMed - as supplied by publisher]
Preoperative optimization for major hepatic resection.
Langenbecks Arch Surg. 2017 Nov 18;:
Authors: Walcott-Sapp S, Billingsley KG
PURPOSE: Major hepatic resections are performed for primary hepatobiliary malignancies, metastatic disease, and benign lesions. Patients with chronic liver disease, including cirrhosis and steatosis, are at an elevated risk of malnutrition and impaired strength and exercise capacity, deficits which cause increased risk of postoperative complications and mortality. The aims of this report are to discuss the pathophysiology of changes in nutrition, exercise capacity, and muscle strength in patient populations likely to require major hepatectomy, and review recommendations for preoperative evaluation and optimization.
METHODS: Nutritional and functional impairment in preoperative hepatectomy patients, especially those with underlying liver disease, have a complex and multifactorial physiologic basis that is not completely understood.
RESULTS: Recognition of malnutrition and compromised strength and exercise tolerance preoperatively can be difficult, but is critical in providing the opportunity to intervene prior to major hepatic resection and potentially improve postoperative outcomes. There is promising data on a variety of nutritional strategies to ensure adequate intake of calories, proteins, vitamins, and minerals in patients with cirrhosis and reduce liver size and degree of fatty infiltration in patients with hepatic steatosis. Emerging evidence supports structured exercise programs to improve exercise tolerance and counteract muscle wasting.
CONCLUSIONS: The importance of nutrition and functional status in patients indicated for major liver resection is apparent, and emerging evidence supports structured preoperative preparation programs involving nutritional intervention and exercise training. Further research is needed in this field to develop optimal protocols to evaluate and treat this heterogeneous cohort of patients.
PMID: 29150719 [PubMed - as supplied by publisher]
Setting the pace: insights and advancements gained while preparing for an FES bike race.
J Neuroeng Rehabil. 2017 Nov 17;14(1):118
Authors: McDaniel J, Lombardo LM, Foglyano KM, Marasco PD, Triolo RJ
The reduction in physical activity following a spinal cord injury often leads to a decline in mental and physical health. Developing an exercise program that is effective and enjoyable is paramount for this population. Although functional electrical stimulation (FES) stationary cycling has been utilized in rehabilitation settings, implementing an overground cycling program for those with spinal cord injuries has greater technical challenges. Recently our laboratory team focused on training five individuals with compete spinal cord injuries utilizing an implanted pulse generator for an overground FES bike race in CYBATHLON 2016 held in Zurich, Switzerland. The advancements in muscle strength and endurance and ultimately cycling power our pilots made during this training period not only helped propel our competing pilot to win gold at the CYBATHLON 2016, but allowed our pilots to ride their bikes outside within their communities. Such a positive outcome has encouraged us to put effort into developing more widespread use of FES overground cycling as a rehabilitative tool for those with spinal cord injuries. This commentary will describe our approach to the CYBATHLON 2016 including technological advancements, bike design and the training program.
PMID: 29149885 [PubMed - in process]