Continuous low- to moderate-intensity exercise training is as effective as moderate- to high-intensity exercise training at lowering blood HbA1c in obese type 2 diabetes patients

Aims/hypothesis: Exercise represents an effective interventional strategy to improve glycaemic control in type 2 diabetes patients. However, the impact of exercise intensity on the benefits of exercise training remains to be established. In the present study, we compared the clinical benefits of 6 months of continuous low- to moderate-intensity exercise training with those of continuous moderate- to high-intensity exercise training, matched for energy expenditure, in obese type 2 diabetes patients. Methods: Fifty male obese type 2 diabetes patients (age 59∈±∈8 years, BMI 32∈± ∈4 kg/m2) participated in a 6 month continuous endurance-type exercise training programme. All participants performed three supervised exercise sessions per week, either 55 min at 50% of whole body peak oxygen uptake left(VO2peak) (low to moderate intensity) or 40 min at 75% of VO2peak (moderate to high intensity). Oral glucose tolerance, blood glycated haemoglobin, lipid profile, body composition, maximal workload capacity, whole body and skeletal muscle oxidative capacity and skeletal muscle fibre type composition were assessed before and after 2 and 6 months of intervention. Results: The entire 6 month intervention programme was completed by 37 participants. Continuous endurance-type exercise training reduced blood glycated haemoglobin levels, LDL-cholesterol concentrations, body weight and leg fat mass, and increased VO2peak, lean muscle mass and skeletal muscle cytochrome c oxidase and citrate synthase activity (p∈<∈0. 05). No differences were observed between the groups training at low to moderate or moderate to high intensity. Conclusions/interpretation: When matched for energy cost, prolonged continuous low- to moderate-intensity endurance-type exercise training is equally effective as continuous moderate- to high-intensity training in lowering blood glycated haemoglobin and increasing whole body and skeletal muscle oxidative capacity in obese type 2 diabetes patients. © 2009 Springer-Verlag

Exercise in type 2 diabetes: to resist or to endure?

There is now evidence that a single bout of endurance (aerobic) or resistance exercise reduces 24 h post-exercise subcutaneous glucose profiles to the same extent in insulin-resistant humans with or without type 2 diabetes. However, it remains to be determined which group would benefit most from specific exercise protocols, particularly with regard to long-term glycaemic control. Acute aerobic exercise first accelerates translocation of myocellular glucose transporters via AMP-activated protein kinase, calcium release and mitogen-activated protein kinase, but also improves insulin-dependent glucose transport/phosphorylation via distal components of insulin signalling (phosphoinositide-dependent kinase 1, TBC1 domain family, members 1 and 4, Rac1, protein kinase C). Post-exercise effects involve peroxisome-proliferator activated receptor-γ coactivator 1α and lead to ATP synthesis, which may be modulated by variants in genes such as NDUFB6. While mechanisms of acute resistance-type exercise are less clear, chronic resistance training activates the mammalian target of rapamycin/serine kinase 6 pathway, ultimately increasing protein synthesis and muscle mass. Over the long term, adherence to rather than differences in metabolic variables between specific modes of regular exercise might ultimately determine their efficacy. Taken together, studies are now needed to address the variability of individual responses to long-term resistance and endurance training in real life

Effectiveness and cost-effectiveness of 'BeweegKuur', a combined lifestyle intervention in the Netherlands: Rationale, design and methods of a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Improving the lifestyle of overweight and obese adults is of increasing interest in view of its role in several chronic diseases. Interventions aiming at overweight or weight-related chronic diseases suffer from high drop-out rates. It has been suggested that Motivational Interviewing and more frequent and more patient-specific coaching could decrease the drop-out rate. 'BeweegKuur' is a multidisciplinary lifestyle intervention which offers three programmes for overweight persons. The effectiveness and the cost-effectiveness of intensively guided programmes, such as the 'supervised exercise programme' of 'BeweegKuur', for patients with high weight-related health risk, remain to be assessed. Our randomized controlled trial compares the expenses and effects of the 'supervised exercise programme' with those of the less intensively supervised 'start-up exercise programme'.</p> <p>Methods/Design</p> <p>The one-year intervention period involves coaching by a lifestyle advisor, a physiotherapist and a dietician, coordinated by general practitioners (GPs). The participating GP practices have been allocated to the interventions, which differ only in terms of the amount of coaching offered by the physiotherapist. Whereas the 'start-up exercise programme' includes several consultations with physiotherapists to identify barriers hampering independent exercising, the 'supervised exercise programme' includes more sessions with a physiotherapist, involving exercise under supervision. The main goal is transfer to local exercise facilities. The main outcome of the study will be the participants' physical activity at the end of the one-year intervention period and after one year of follow-up. Secondary outcomes are dietary habits, health risk, physical fitness and functional capacity. The economic evaluation will consist of a cost-effectiveness analysis and a cost-utility analysis. The primary outcome measures for the economic evaluation will be the physical activity and the number of quality-adjusted life years. Costs will be assessed from a societal perspective with a time horizon of two years. Additionally, a process evaluation will be used to evaluate the performance of the intervention and the participants' evaluation of the intervention.</p> <p>Discussion</p> <p>This study is expected to provide information regarding the additional costs and effects of the 'supervised exercise programme' in adults with very high weight-related health risk.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN46574304">ISRCTN46574304</a></p

Evaluation of the efficacy and tolerability of miglitol in Chinese patients with type 2 diabetes mellitus inadequately controlled by diet and sulfonylureas

The objective of this study is to examine the efficacy and tolerability of miglitol with respect to improving glycemic control in Chinese patients with type 2 diabetes mellitus inadequately controlled by diet and sulfonylurea treatment. This was a randomized, double-blinded, placebo-controlled, multicenter study. A total of 105 patients were randomized to receive 24 weeks of treatment with miglitol (n = 52; titrated from 50 mg to 100 mg 3 times daily) or placebo (n = 53). Concomitant sulfonylurea treatment and diet remained unchanged. The primary endpoint was change in glycated hemoglobin (HbA1c) from baseline at 24 weeks. Secondary endpoints were changes in fasting plasma glucose (FPG), postprandial plasma glucose (PPG), and postprandial serum insulin (PSI). The miglitol treatment group showed significantly greater reductions in HbA1c and PPG levels compared with the placebo group. With respect to adverse events, abdominal discomfort, diarrhea, and hypoglycemia occurred with similar frequency in both groups. Results of this study indicate that miglitol significantly improves metabolic control in Chinese patients with type 2 diabetes mellitus. Miglitol is safe and well tolerated, with the exception of abdominal discomfort. Therefore, miglitol may be a useful adjuvant therapy for Chinese patients with type 2 diabetes mellitus inadequately controlled by diet and sulfonylurea treatment

Fitness consultations in routine care of patients with type 2 diabetes in general practice: an 18-month non-randomised intervention study

<p>Abstract</p> <p>Background</p> <p>Increasing physical activity is a cornerstone in the treatment of type 2 diabetes and in general practice it is a challenge to achieve long-term adherence to this life style change. The aim of this study was to investigate in a non-randomised design whether the introduction of motivational interviewing combined with fitness tests in the type 2 diabetes care programme was followed by a change in cardio-respiratory fitness expressed by VO_2max, muscle strength of upper and lower extremities, haemoglobin A_1c(HbA_1c) and HDL-cholesterol.</p> <p>Methods</p> <p>Uncontrolled 18-month intervention study with follow-up and effect assessment every 3 months in a primary care unit in Denmark with six general practitioners (GPs). Of 354 eligible patients with type 2 diabetes, 127 (35.9%) were included. Maximum work capacity was tested on a cycle ergometer and converted to VO_2max. Muscle strength was measured with an arm curl test and a chair stand test. The results were used in a subsequent motivational interview conducted by one of the GPs. Patients were encouraged to engage in lifestyle exercise and simple home-based self-managed exercise programmes. Data were analysed with mixed models.</p> <p>Results</p> <p>At end of study, 102 (80.3%) participants remained in the intervention. Over 18 months, VO_2maxincreased 2.5% (p = 0.032) while increases of 33.2% (p < 0.001) and 34.1% (p < 0.001) were registered for the arm curl test and chair stand test, respectively. HDL-cholesterol increased 8.6% (p < 0.001), but HbA_1cremained unchanged (p = 0.57) on a low level (6.8%). Patients without cardiovascular disease or pain from function limitation increased their VO_2maxby 5.2% (p < 0.0001) and 7.9% (p = 0.0008), respectively.</p> <p>Conclusions</p> <p>In this 18-month study, participants who had repeated fitness consultations, including physical testing and motivational interviewing to improve physical activity, improved VO_2max, muscle strength, and lipid profile. Our results indicate that physical testing combined with motivational interviewing is feasible in a primary health care setting. Here, a fitness consultation tailored to the individual patient, his/her comorbidities and conditions in the local area can be incorporated into the diabetes programme to improve patients' muscle strength and cardio-respiratory fitness.</p

Exercise therapy in Type 2 diabetes

Structured exercise is considered an important cornerstone to achieve good glycemic control and improve cardiovascular risk profile in Type 2 diabetes. Current clinical guidelines acknowledge the therapeutic strength of exercise intervention. This paper reviews the wide pathophysiological problems associated with Type 2 diabetes and discusses the benefits of exercise therapy on phenotype characteristics, glycemic control and cardiovascular risk profile in Type 2 diabetes patients. Based on the currently available literature, it is concluded that Type 2 diabetes patients should be stimulated to participate in specifically designed exercise intervention programs. More attention should be paid to cardiovascular and musculoskeletal deconditioning as well as motivational factors to improve long-term treatment adherence and clinical efficacy. More clinical research is warranted to establish the efficacy of exercise intervention in a more differentiated approach for Type 2 diabetes subpopulations within different stages of the disease and various levels of co-morbidity

Prediction of Muscle Energy States at Low Metabolic Rates Requires Feedback Control of Mitochondrial Respiratory Chain Activity by Inorganic Phosphate

The regulation of the 100-fold dynamic range of mitochondrial ATP synthesis flux in skeletal muscle was investigated. Hypotheses of key control mechanisms were included in a biophysical model of oxidative phosphorylation and tested against metabolite dynamics recorded by 31P nuclear magnetic resonance spectroscopy (31P MRS). Simulations of the initial model featuring only ADP and Pi feedback control of flux failed in reproducing the experimentally sampled relation between myoplasmic free energy of ATP hydrolysis (ΔGp = ΔGpo′+RT ln ([ADP][Pi]/[ATP]) and the rate of mitochondrial ATP synthesis at low fluxes (<0.2 mM/s). Model analyses including Monte Carlo simulation approaches and metabolic control analysis (MCA) showed that this problem could not be amended by model re-parameterization, but instead required reformulation of ADP and Pi feedback control or introduction of additional control mechanisms (feed forward activation), specifically at respiratory Complex III. Both hypotheses were implemented and tested against time course data of phosphocreatine (PCr), Pi and ATP dynamics during post-exercise recovery and validation data obtained by 31P MRS of sedentary subjects and track athletes. The results rejected the hypothesis of regulation by feed forward activation. Instead, it was concluded that feedback control of respiratory chain complexes by inorganic phosphate is essential to explain the regulation of mitochondrial ATP synthesis flux in skeletal muscle throughout its full dynamic range

Testing the effectiveness of a self-efficacy based exercise intervention for inactive people with type 2 diabetes mellitus: design of a controlled clinical trial

<p>Abstract</p> <p>Background</p> <p>Sufficient exercise is important for people with Type 2 Diabetes Mellitus (T2DM), as it can prevent future health problems. Despite, it is estimated that only 30-40% of people with T2DM are sufficiently active. One of the psychosocial constructs that is believed to influence physical activity behaviour, is exercise self-efficacy. The goal of this study is to evaluate a patient-tailored exercise intervention for people with T2DM that takes exercise self-efficacy into account.</p> <p>Methods/Design</p> <p>This study is conducted as a non-randomized controlled clinical trial. Patients are eligible when they are diagnosed with T2DM, exercise less than advised in the ADA guideline of 150 min/week of moderate-intensity aerobic physical activity, have an BMI >25 and are between 18 and 80 years old. Recruitment takes place at a Primary care organization of general practitioners and practice nurses in the south of the Netherlands.</p> <p>Participants are allocated to three groups: An <it>advice intervention</it> -for participants with a high exercise self-efficacy score- in which participants receive a patient-tailored exercise intervention, an <it>intensive intervention</it> -for participants with a low exercise self-efficacy score- in which participants receive a patient-tailored exercise intervention accomplished by a group based intervention, and a <it>control group</it> in which participants receive regular Dutch diabetes care. The primary outcome measure of this study is physical activity. Secondary outcome measures are health status, (symptoms of) depression, exercise self-efficacy, Body Mass Index (BMI), blood pressure and glycemic control.</p> <p>Discussion</p> <p>We aimed to design an intervention that can be implemented in Primary care, but also to design an easy accessible program. This study is innovative as it is -to our best knowledge- the first study that takes level of exercise self-efficacy of people with T2DM into account by means of giving extra support to those with the lowest exercise self-efficacy. If the program succeeds in increasing the amount of physical activity it can be implemented in regular primary care.</p> <p>Trial registration</p> <p>Dutch Trial Register NTR2734</p