Exercise in obesity, metabolic syndrome, and diabetes

The risk of developing both metabolic syndrome and type 2 diabetes mellitus (T2DM) is inversely associated with regular exercise training (ET). Excess weight is also strongly associated with increased risk of both metabolic syndrome and T2DM. There is strong evidence that even a moderate amount of weight loss achieved through changes in diet and ET can greatly reduce the risk of developing T2DM.For the purpose of general health, exercise programs should have both aerobic and resistance training components. The 2008 federal physical activity (PA) guidelines recommend obtaining at least 150 minutes per week of moderate-intensity PA, 75 minutes per week of vigorous-intensity PA, or a combination of the 2. In addition, all individuals should strive for at least 2 days per week of resistance training activity. For the purpose of weight loss, the combination of ET and reduced energy intake has been found to be more effective than either alone.     

Resistance training,visceral obesity and inflammatory response: a review of the evidence

Intra‐abdominal obesity is an important risk factor for low‐grade inflammation, which is associated with increased risk for diabetes mellitus and cardiovascular disease. For the most part, recommendations to treat or prevent overweight and obesity via physical activity have focused on aerobic endurance training as it is clear that aerobic training is associated with much greater energy expenditure during the exercise session than resistance training. However, due to the metabolic consequences of reduced muscle mass, it is understood that normal ageing and/or decreased physical activity may lead to a higher prevalence of metabolic disorders. Whether resistance training alters visceral fat and the levels of several pro‐inflammatory cytokines produced in adipose tissue has not been addressed in earlier reviews. Because evidence suggests that resistance training may promote a negative energy balance and may change body fat distribution, it is possible that an increase in muscle mass after resistance training may be a key mediator leading to a better metabolic control. Considering the benefits of resistance training on visceral fat and inflammatory response, an important question is: how much resistance training is needed to confer such benefits? Therefore, the purpose of this review was to address the importance of resistance training on abdominal obesity, visceral fat and inflammatory response.     

Obesity,risk of diabetes and role of physical activity,exercise training and cardiorespiratory fitness

The epidemic of obesity contributes to the burden of type 2 diabetes mellitus (T2DM) in the United States and worldwide. Importantly, obesity is not only preventable but can be treated, particularly with lifestyle modifications to forestall T2DM in those with excess adiposity. The mechanisms linking obesity to T2DM are numerous and involve adipose tissue remodeling as a result of unhealthy behaviors, including unhealthy diet, reduced physical activity (PA) and exercise training (ET), and increased sedentary behaviors. Taken together, these factors markedly reduce cardiorespiratory fitness (CRF), one of the strongest predictors for cardiovascular outcomes and all-cause mortality in the general population, but also in those with T2DM.In this review we describe the mechanisms leading to adipose tissue remodeling resulting in obesity, as well as the mechanisms linking excess adiposity to insulin resistance and, in turn, T2DM. We then present the therapeutic strategies that can be implemented in obesity to prevent T2DM, with a brief discussion on weight loss, and greater emphasis on PA and ET. We finally present the evidence to support the beneficial effects of such strategies in patients with established T2DM and discuss the importance of achieving improvements in CRF in this population to potentially improve clinical outcomes.     

Consensus physical activity guidelines for Asian Indians

India is currently undergoing rapid economic, demographic, and lifestyle transformations. A key feature of the latter transformation has been inappropriate and inadequate diets and decreases in physical activity. Data from various parts of India have shown a steady increase in the prevalence of lifestyle-related diseases such as type 2 diabetes mellitus (T2DM), the metabolic syndrome, hypertension, coronary heart disease (CHD), etc., frequently in association with overweight or obesity. Comparative data show that Asian Indians are more sedentary than white Caucasians. In this review, the Consensus Group considered the available physical activity guidelines from international and Indian studies and formulated India-specific guidelines. A total of 60?min of physical activity is recommended every day for healthy Asian Indians in view of the high predisposition to develop T2DM and CHD. This should include at least 30?min of moderate-intensity aerobic activity, 15?min of work-related activity, and 15?min of muscle-strengthening exercises. For children, moderate-intensity physical activity for 60?min daily should be in the form of sport and physical activity. This consensus statement also includes physical activity guidelines for pregnant women, the elderly, and those suffering from obesity, T2DM, CHD, etc. Proper application of guidelines is likely to have a significant impact on the prevalence and management of obesity, the metabolic syndrome, T2DM, and CHD in Asian Indians.     

Morphological assessment of pancreatic islet hormone content following aerobic exercise training in rats with poorly controlled Type 1 diabetes mellitus

Regular exercise has been shown to improve many complications of Type 1 diabetes mellitus (T1DM) including enhanced glucose tolerance and increased cardiac function. While exercise training has been shown to increase insulin content in pancreatic islets of rats with T1DM, experimental models were severely hyperglycemic and not undergoing insulin treatment. Further, research to date has yet to determine how exercise training alters glucagon content in pancreatic islets. The purpose of the present investigation was to determine the impact of a 10-week aerobic training program on pancreatic islet composition in insulin-treated rats with T1DM. Second, it was determined whether the acute, exercise-mediated reduction in blood glucose experienced in rats with T1DM would become larger in magnitude following aerobic exercise training. Diabetes was induced in male Sprague-Dawley rats by multiple low dose injections of streptozotocin (20mg/kg i.p.) and moderate intensity aerobic exercise training was performed on a motorized treadmill for one hour per day for a total of 10 weeks. Rats with T1DM demonstrated significantly less islet insulin, and significantly more islet glucagon hormone content compared with non-T1DM rats, which did not significantly change following aerobic training. The reduction in blood glucose in response to a single exercise bout was similar across 10 weeks of training. Results also support the view that different subpopulations of islets exist, as small islets (<50 μm diameter) had significantly more insulin and glucagon in rats with and without T1DM.     

Morphological assessment of pancreatic islet hormone content following aerobic exercise training in rats with poorly controlled Type 1 diabetes mellitus

Regular exercise has been shown to improve many complications of Type 1 diabetes mellitus (T1DM) including enhanced glucose tolerance and increased cardiac function. While exercise training has been shown to increase insulin content in pancreatic islets of rats with T1DM, experimental models were severely hyperglycemic and not undergoing insulin treatment. Further, research to date has yet to determine how exercise training alters glucagon content in pancreatic islets. The purpose of the present investigation was to determine the impact of a 10-week aerobic training program on pancreatic islet composition in insulin-treated rats with T1DM. Second, it was determined whether the acute, exercise-mediated reduction in blood glucose experienced in rats with T1DM would become larger in magnitude following aerobic exercise training. Diabetes was induced in male Sprague-Dawley rats by multiple low dose injections of streptozotocin (20mg/kg i.p.) and moderate intensity aerobic exercise training was performed on a motorized treadmill for one hour per day for a total of 10 weeks. Rats with T1DM demonstrated significantly less islet insulin, and significantly more islet glucagon hormone content compared with non-T1DM rats, which did not significantly change following aerobic training. The reduction in blood glucose in response to a single exercise bout was similar across 10 weeks of training. Results also support the view that different subpopulations of islets exist, as small islets (<50 μm diameter) had significantly more insulin and glucagon in rats with and without T1DM.     

The effect of aerobic exercise training on β-cell function and circulating levels of adipsin in community of obese women with type 2 diabetes mellitus

It has been suggested that adipsin might affect insulin secretion or glucose homeostasis, and thus, there can be a missing link between β-cell function, obesity, and type 2 diabetes. However, as yet, the function of adipsin has been unknown and needs to be evaluated over a longer term. The objective of this semi-experimental study was to compare the effect of aerobic exercise training on β-cell function and circulating levels of adipsin in obese women with type 2 diabetes mellitus (T2DM). The T2DM women with fasting plasma glucose >126 mg/dl were targeted and chosen for further evaluations. Twenty-four women aged 35–50 years participated in the study. Subjects were divided in two groups of C and E standing for control and experimental groups, respectively (group C/n?=?12, group E/n?=?12). Anthropometric variable measurements, including fasting plasma glucose, insulin, lipid profiles, free fat acid (FFA), HOMA-IR, HOMA-β, and serum adipsin were obtained from the study samples. Following 8 weeks of aerobic training, serum adipsin levels did not alter in group E, whereas, the levels of HOMA-IR, fasting plasma glucose, weight, BMI, and percent body fat levels significantly changed in group E compared to the baseline. Other variables did not alter significantly. The study indicated that aerobic exercise training in T2DM patients had positive health effects especially on glycemic control and pancreatic β-cell function with no significant change in adipsin levels. However, adipsin is a newly identified immune regulator of metabolic diseases and more studies are needed to understand the signaling mechanisms of adipsin T2DM population.     

Substrate oxidation,obesity and exercise training

Regular physical exercise is of the utmost importance in the treatment of obesity because exercise is one of the factors determining long-term weight maintenance in weight reduction programmes and because exercise has been associated with a reduced risk for developing type 2 diabetes mellitus and cardiovascular disease. Obesity is associated with an impaired utilization of fat as a fuel during post-absorptive conditions, during beta-adrenergic stimulation and possibly during exercise, although the latter data are controversial.One of the underlying mechanisms for the positive effect of exercise training in obesity may be related to its effects on fat utilization because exercise training has been shown to increase basal fat oxidation and exercise fat oxidation in lean volunteers. Data on the effect of aerobic exercise training on exercise fat oxidation are controversial, whereas the available data indicate that exercise training may not be able to increase resting fat oxidation or 24-hour fat oxidation in obese subjects. Because disturbed muscle fat oxidation may be a primary event in the aetiology of obesity it is of the utmost importance to obtain more information on how and whether exercise training may be able to compensate for these impairments.     

Exercise as a complementary medicine intervention in type 2 diabetes mellitus: A systematic review with narrative and qualitative synthesis of evidence

Background and aimsType 2 diabetes mellitus (T2DM) is a rapidly growing public health issue. This systematic review aimed to narrate and qualitatively synthesize evidence and recommendations of physical activity/exercise for patients with T2DM.MethodsThe databases Medline through Pubmed, Cochrane, and Scopus were systematically searched from inception to February 08, 2020 using MeSH terms related to “diabetes mellitus” and “physical activity/exercise”. Studies were included if they reported on the roles of physical activity/exercise in managing patients with T2DM or effects of physical activity/exercise on glycemic control. Documents identified through the search were analyzed and evidence and recommendations were synthesized qualitatively.ResultsData were extracted from 16 original articles and 11 systematic reviews with meta-analyses. A qualitative summary of evidence included general items (n = 6) and recommendations for physical activity/exercise (n = 12). Physical activity/exercise can reduce incidence of T2DM, hyperinsulinemia, fasting plasma/blood glucose, HbA1c, body fats, cholesterol, blood pressure, heart rate, cardiovascular risk, and dosage of antidiabetic medications. Physical activity/exercise can improve sensitivity to insulin, muscle strength, oxygen consumption, aerobic capacity, and mental health of patients with T2DM.ConclusionDespite the increasing interest in incorporating physical activity/exercise in the management of T2DM and improving healthcare delivery, there are still limited clear instructions and guidelines for both the patient and the healthcare provider.     

Brief report of the effects of the aerobic,resistance, and high-intensity interval training in type 2 diabetes mellitus individuals

Insulin resistance is the main feature in type 2 diabetes mellitus (T2DM). Insulin resistance occurs when there is a failure or reduced activation of phosphoidilinositol-3-kinase pathway. Physical exercise (PE) can prevent and fight insulin resistance. Resistance training (RT), aerobic training (AT), and high-intensity interval training (HIIT) are different types of PE and have the ability to produce increased phosphorylation of insulin receptors favoring the increasing of the activity of insulin pathways during and after physical activity. The objective of this study was to check through a literature review the benefits of AT, RT, and HIIT over insulin resistance in T2DM. It was made a research in PubMed using the words PE, insulin resistance, diabetes, AT, RT, and HIIT. The most relevant papers with results over glycemia were selected. There was better glycemia management in moderate AT and RT, and during HIIT sessions. HIIT presented increased cardiovascular risks to T2DM individuals. Lower risks with more benefits were seen at moderate AT. All three types of PE can be performed as a tool to prevent and fight insulin resistance in T2DM. When evaluating safety and benefits to diabetics, moderate AT provides best benefits than RT and HIIT to T2DM individuals.     

Gut microbiota and physical exercise in obesity and diabetes – A systematic review

Background and aimThe gut microbiota (GM) plays an essential role in maintaining health, and imbalance in its composition is associated with the physiopathogenesis of metabolic diseases, such as obesity and type 2 diabetes mellitus (T2DM). Diet and antibiotics are known modulators of GM, but the influence of physical exercise in modulating the diversity and abundance of hindgut bacteria is still poorly understood. The aim of this systematic review was to investigate the scientific evidence about the effect of physical exercise on GM modulation in subjects with obesity and T2DM.Methods and resultsA search in PubMed, Web of Science, Scopus, Cochrane and Embase databases using keywords related to gut microbiota, physical exercise and metabolic diseases was performed. Eight clinical studies met the inclusion criteria, six in subjects with obesity and two in individuals with T2DM. In three studies carried out in individuals with obesity, exercise was able to positively modulate the diversity of GM and the abundance of some species of bacteria, mostly by increasing the Bifidobacteriaceae family, and the Bacteroides and Akkermansia genera, and by decreasing the Proteobacteria phylum. The studies in subjects with T2DM found that physical exercise may reduce metabolic endotoxemia markers.ConclusionsPhysical exercise may be a beneficial modulation strategy of GM composition in metabolic diseases, specifically aerobic exercises carried out for at least 6 weeks with moderate or high intensity. Nevertheless, well-designed clinical trials are needed to clarify the role of physical exercise on GM in subjects with obesity and T2DM.     

The role of exercise in the treatment of type 1 diabetes

Although physical activity has been associated with cardiovascular mortality reduction in type-1 diabetes (DM1) patients, many points in the topic 'exercise' deserve a closer look. For example: contradictory data have been reported regarding the benefits of physical activity on metabolic control in these patients. Still contradictory is the type of exercise that brings more benefit in this group. Another issue is the best way of reducing insulin doses for exercise. This article intent to discuss these topics. The effect of exercise on metabolic control in DM1 is still contradictory. Some authors show a beneficial effect on glycated hemoglobin (A1c) and others do not. Another point to be analized is which type of exercise is better for these patients: aerobic or of resistance. There is a lack of information related to the effect of resistance exercises without the aerobic training on metabolic control in type-1 diabetes. The effect of exercise on lipid profile in DM1 is another issue. The intensity and duration of the exercises, the level of physical activity, the duration of the disease and the presence of cronic complications are some points that might be taken into consideration before starting an exercise program. Guidelines for the reduction in insulin dose or the use of carbohydrate are strategies to avoid hypoglycemia related to exercises. Hydration and self-monitored blood glucose levels are also very important topics. This article will also discuss the clinical evaluation before doing any exercise.     

Type 2 diabetes mellitus in children and adolescents

Over the last decade, there has been an alarming increase of Type 2 diabetes mellitus (T2DM) in youths, concomitant with the rise of obesity in this age group. T2DM is a progressive disease with a gradual increase in insulin resistance associated later with a decline in insulin secretion with fasting hyperglycemia. Prevalence of T2DM in children is mostly linked to some risk factors: obesity and sedentary lifestyle, puberty, membership of ethnic minorities, features of insulin resistance, family history of T2DM, female gender and perinatal factors. Prevention is essential and can be considered a public health approach directed to the general population. Treatment of T2DM in youth is complex and based on different strategies: diet, exercise and pharmacotherapy. An appropriated intervention program must be started early, in order to prevent or retard the progression of the disease and associated comorbidities.     

Gastroparesis in type 2 diabetes mellitus: Prevalence,etiology, diagnosis,and treatment

The worldwide epidemic of type 2 diabetes mellitus (T2DM) is a substantial economic and social burden. Although gastroparesis associated with type 1 diabetes mellitus (T1DM) has been recognized for years, only recently have studies shown that patients with T2DM also have high rates of gastroparesis. Individuals with T2DM constitute 90% to 95% of the diabetic population. Unique characteristics that distinguish this population are obesity, insulin resistance, and associated comorbidities. These features highlight the importance of investigating gastric emptying in individuals with T2DM and upper gastrointestinal symptoms. The purpose of this review is to examine the literature pertaining to diabetes and the effect of diabetes on gastric neuromuscular function, with a focus on T2DM. An understanding of gastric motility in T2DM is important to diagnose gastroparesis, to treat upper gastrointestinal symptoms, and to restore normal gastric motility, which may lead, in turn, to improved glucose control.     

Effects of glucocorticoids and exercise on pancreatic β-cell function and diabetes development

Peripheral insulin resistance and pancreatic β‐cell dysfunction are hallmark characteristics of type 2 diabetes mellitus (T2DM). Several contributing factors have been proposed to promote these two defects in individuals with T2DM, including physical inactivity and chronic exposure to various psychosocial factors that increase the body's exposure to glucocorticoids, the main stress hormones in humans. Initially, β‐cells have been shown to adapt to these stimuli, a phenomenon known as β‐cell ‘compensation’. However, long‐term exposure to these physiologic and psychological stressors induces islet failure. Interestingly, glucocorticoids stimulate β‐cell mass growth in parallel with promoting severe insulin resistance, the former being an important adaptive response to the latter. The direct relationship between glucocorticoids and β‐cell dysfunction remains a controversial area of research. Elevations in circulating and/or tissue specific glucocorticoids have been associated with the development of obesity and T2DM in human and rodent models; however, the progression from insulin resistance to overt T2DM is highly disputed with respect to the in vivo and in vitro effects of glucocorticoids. Paradoxically, both intermittent physical stress and regular exercise alleviate insulin resistance and help to preserve β‐cell mass, potentially by lowering glucocorticoid levels. Recent studies have begun to examine the mechanisms of intermittent and chronic glucocorticoid exposure and regular exercise in altering β‐cell function. This review highlights recent discoveries on the physiological regulation of β‐cells and diabetes development in conditions of elevated glucocorticoids, regular exercise and intermittent stress. Copyright © 2012 John Wiley & Sons, Ltd.     

调节糖脂代谢的肌肉因子Irisin

规律的运动锻炼可改善T2DM、肥胖症和心血管疾病等代谢性疾病.Irisin是新发现的肌肉因子,无论在啮齿类动物还是人体内,运动后Irisin浓度均上升.推测Irisin可能具有促进白色脂肪棕色化、增加能量消耗、改善IR、调节糖脂平衡的作用.     

What should the clinician tell patients with mild hypertension about physical activity?

Recent guidelines recommend lifestyle measures, with physical activity as an integral component, for all patients with hypertension or prehypertension to lower blood pressure and control other risk factors. This review discusses both acute and long-term effects of dynamic aerobic endurance exercise and resistance exercise as nonpharmacologic tools to reduce blood pressure, respectively. The optimal exercise characteristics to lower blood pressure need to be more precisely defined, especially with regard to resistance exercise; so far, these effects have been shown to be immediate and elicited by low-intensity short-duration exercise. Based on the current evidence, hypertensive patients should be recommended to exercise on most, preferably all, days of the week, with moderate intensity (40% to 60% of VO₂ reserve) for at least 30 minutes of continuous or accumulated physical activity per day, consisting primarily of endurance training but supplemented by resistance training.     

Efficacy of population‐wide diabetes and obesity prevention programs: An overview of systematic reviews on proximal,intermediate, and distal outcomes and a meta‐analysis of impact on BMI

We conducted an overview of systematic reviews and a meta‐analysis of the impact on body mass index (BMI) of primary studies of population‐wide obesity and diabetes prevention programs, in order to evaluate their efficacy. We searched eight databases for reviews of population‐level programs reporting effect on diet, physical activity, BMI, or prevalence of obesity/overweight or type 2 diabetes mellitus (T2DM). Meta‐analysis of primary studies within reviews reporting effect on BMI. Interventions were categorized using ANGELO framework and quality assessment using AMSTAR. Fifty‐three systematic reviews were included. Primary studies were largely natural experiments or cross‐sectional studies of national data. Increased price of sugar‐sweetened beverages (SSBs) and fast food, decreased price of fruit and vegetables, food labelling, and grocery store interventions were associated with positive effects on diet. Park and playground renovations and point‐of‐choice prompts to increase stair use were associated with positive effects on physical activity. Increased price of SSBs, menu labelling, grocery store interventions, and multicomponent interventions were associated with small reductions in BMI. There was insufficient evidence of impact of any interventions on the prevalence of overweight, obesity, or T2DM. We have identified a promising suite of population‐wide actions to improve diet, increase physical activity, and reduce BMI. Impact on subsequent incidence of T2DM remains speculative.     

Physical activity is the key determinant of skeletal muscle mitochondrial function in type 2 diabetes

Context: Conflicting data exist on mitochondrial function and physical activity in type 2 diabetes mellitus (T2DM) development. Objective: The aim was to assess mitochondrial function at different stages during T2DM development in combination with physical exercise in longstanding T2DM patients. Design and Methods: We performed cross-sectional analysis of skeletal muscle from 12 prediabetic 11 longstanding T2DM male subjects and 12 male controls matched by age and body mass index. Intervention: One-year intrasubject controlled supervised exercise training intervention was done in longstanding T2DM patients. Main Outcome Measurements: Extensive ex vivo analyses of mitochondrial quality, quantity, and function were collected and combined with global gene expression analysis and in vivo ATP production capacity after 1 yr of training. Results: Mitochondrial density, complex I activity, and the expression of Krebs cycle and oxidative phosphorylation system-related genes were lower in longstanding T2DM subjects but not in prediabetic subjects compared with controls. This indicated a reduced capacity to generate ATP in longstanding T2DM patients only. Gene expression analysis in prediabetic subjects suggested a switch from carbohydrate toward lipid as an energy source. One year of exercise training raised in vivo skeletal muscle ATP production capacity by 21 ± 2% with an increased trend in mitochondrial density and complex I activity. In addition, expression levels of β-oxidation, Krebs cycle, and oxidative phosphorylation system-related genes were higher after exercise training. Conclusions: Mitochondrial dysfunction is apparent only in inactive longstanding T2DM patients, which suggests that mitochondrial function and insulin resistance do not depend on each other. Prolonged exercise training can, at least partly, reverse the mitochondrial impairments associated with the longstanding diabetic state.