Exercise prescription for patients with type 2 diabetes and pre-diabetes: a position statement from Exercise and Sport Science Australia

Diabetic foot and exercise therapy: step by step the role of rigid posture and biomechanics treatment

Lower extremity ulcers represent a serious and costly complication of diabetes mellitus. Many factors contribute to the development of diabetic foot. Peripheral neuropathy and peripheral vascular disease are the main causes of foot ulceration and contribute in turn to the growth of additional risk factors such as limited joint mobility, muscular alterations and foot deformities. Moreover, a deficit of balance, posture and biomechanics can be present, in particular in patients at high risk for ulceration. The result of this process may be the development of a vicious cycle which leads to abnormal distribution of the foot's plantar pressures in static and dynamic postural conditions. This review shows that some of these risk factors significantly improve after a few weeks of exercise therapy (ET) intervention. Accordingly it has been suggested that ET can be an important weapon in the prevention of foot ulcer. The aim of ET can relate to one or more alterations typically found in diabetic patients, although greater attention should be paid to the evaluation and possible correction of body balance, rigid posture and biomechanics. Some of the most important limitations of ET are difficult access to therapy, patient compliance and the transitoriness of the results if the training stops. Many proposals have been made to overcome such limitations. In particular, it is important that specialized centers offer the opportunity to participate in ET and during the treatment the team should work to change the patient's lifestyle by improving the execution of appropriate daily physical activity.

Diabetic cardiomyopathy: mechanisms and new treatment strategies targeting antioxidant signaling pathways

Cardiovascular disease is the primary cause of morbidity and mortality among the diabetic population. Both experimental and clinical evidence suggest that diabetic subjects are predisposed to a distinct cardiomyopathy, independent of concomitant macro- and microvascular disorders. 'Diabetic cardiomyopathy' is characterized by early impairments in diastolic function, accompanied by the development of cardiomyocyte hypertrophy, myocardial fibrosis and cardiomyocyte apoptosis. The pathophysiology underlying diabetes-induced cardiac damage is complex and multifactorial, with elevated oxidative stress as a key contributor. We now review the current evidence of molecular disturbances present in the diabetic heart, and their role in the development of diabetes-induced impairments in myocardial function and structure. Our focus incorporates both the contribution of increased reactive oxygen species production and reduced antioxidant defenses to diabetic cardiomyopathy, together with modulation of protein signaling pathways and the emerging role of protein O-GlcNAcylation and miRNA dysregulation in the progression of diabetic heart disease. Lastly, we discuss both conventional and novel therapeutic approaches for the treatment of left ventricular dysfunction in diabetic patients, from inhibition of the renin-angiotensin-aldosterone-system, through recent evidence favoring supplementation of endogenous antioxidants for the treatment of diabetic cardiomyopathy. Novel therapeutic strategies, such as gene therapy targeting the phosphoinositide 3-kinase PI3K(p110α) signaling pathway, and miRNA dysregulation, are also reviewed. Targeting redox stress and protective protein signaling pathways may represent a future strategy for combating the ever-increasing incidence of heart failure in the diabetic population.

Efficacy of interventions that include diet, aerobic and resistance training components for type 2 diabetes prevention: a systematic review with meta-analysis

Current recommendations for the prevention of type 2 diabetes advise modification of diet and exercise behaviors including both aerobic and resistance training. However, the efficacy of multi-component interventions involving a combination of these three components has not been established. The aims of this review were to systematically review and meta-analyze the evidence on multi-component (diet + aerobic exercise + resistance training) lifestyle interventions for type 2 diabetes prevention. Eight electronic databases (Medline, Embase, SportDiscus, Web of Science, CINAHL, Informit health collection, Cochrane library and Scopus) were searched up to June 2013. Eligible studies 1) recruited prediabetic adults or individuals at risk of type 2 diabetes; 2) conducted diet and exercise [including both physical activity/aerobic and resistance training] programs; and 3) reported weight and plasma glucose outcomes. In total, 23 articles from eight studies were eligible including five randomized controlled trials, one quasi-experimental, one two-group comparison and one single-group pre-post study. Four studies had a low risk of bias (score ≥ 6/10). Median intervention length was 12 months (range 4-48 months) with a follow-up of 18 months (range 6.5-48 months). The diet and exercise interventions varied slightly in terms of their specific prescriptions. Meta-analysis favored interventions over controls for weight loss (-3.79 kg [-6.13, -1.46; 95% CI], Z = 3.19, P = 0.001) and fasting plasma glucose (-0.13 mmol.L⁻¹ [-0.24, -0.02; 95% CI], Z = 2.42, P = 0.02). Diabetes incidence was only reported in two studies, with reductions of 58% and 56% versus control groups. In summary, multi-component lifestyle type 2 diabetes prevention interventions that include diet and both aerobic and resistance exercise training are modestly effective in inducing weight loss and improving impaired fasting glucose, glucose tolerance, dietary and exercise outcomes in at risk and prediabetic adult populations. These results support the current exercise guidelines for the inclusion of resistance training in type 2 diabetes prevention, however there remains a need for more rigorous studies, with long-term follow-up evaluating program efficacy, muscular fitness outcomes, diabetes incidence and risk reduction.

Efficacy of interventions that include diet, aerobic and resistance training components for type 2 diabetes prevention: a systematic review with meta-analysis

Current recommendations for the prevention of type 2 diabetes advise modification of diet and exercise behaviors including both aerobic and resistance training. However, the efficacy of multi-component interventions involving a combination of these three components has not been established. The aims of this review were to systematically review and meta-analyze the evidence on multi-component (diet + aerobic exercise + resistance training) lifestyle interventions for type 2 diabetes prevention. Eight electronic databases (Medline, Embase, SportDiscus, Web of Science, CINAHL, Informit health collection, Cochrane library and Scopus) were searched up to June 2013. Eligible studies 1) recruited prediabetic adults or individuals at risk of type 2 diabetes; 2) conducted diet and exercise [including both physical activity/aerobic and resistance training] programs; and 3) reported weight and plasma glucose outcomes. In total, 23 articles from eight studies were eligible including five randomized controlled trials, one quasi-experimental, one two-group comparison and one single-group pre-post study. Four studies had a low risk of bias (score ≥ 6/10). Median intervention length was 12 months (range 4–48 months) with a follow-up of 18 months (range 6.5 - 48 months). The diet and exercise interventions varied slightly in terms of their specific prescriptions. Meta-analysis favored interventions over controls for weight loss (-3.79 kg [-6.13, -1.46; 95% CI], Z = 3.19, P = 0.001) and fasting plasma glucose (-0.13 mmol.L^-1 [-0.24, -0.02; 95% CI], Z = 2.42, P = 0.02). Diabetes incidence was only reported in two studies, with reductions of 58% and 56% versus control groups. In summary, multi-component lifestyle type 2 diabetes prevention interventions that include diet and both aerobic and resistance exercise training are modestly effective in inducing weight loss and improving impaired fasting glucose, glucose tolerance, dietary and exercise outcomes in at risk and prediabetic adult populations. These results support the current exercise guidelines for the inclusion of resistance training in type 2 diabetes prevention, however there remains a need for more rigorous studies, with long-term follow-up evaluating program efficacy, muscular fitness outcomes, diabetes incidence and risk reduction.

Resistance training for diabetes prevention and therapy: experimental findings and molecular mechanisms

Type 2 diabetes mellitus (T2D) is characterized by insulin resistance, impaired glycogen synthesis, lipid accumulation, and impaired mitochondrial function. Exercise training has received increasing recognition as a cornerstone in the prevention and treatment of T2D. Emerging research suggests that resistance training (RT) has the power to combat metabolic dysfunction in patients with T2D and seems to be an effective measure to improve overall metabolic health and reduce metabolic risk factors in diabetic patients. However, there is limited mechanistic insight into how these adaptations occur. This review provides an overview of the intervention data on the impact of RT on glucose metabolism. In addition, the molecular mechanisms that lead to adaptation in skeletal muscle in response to RT and that are associated with possible beneficial metabolic responses are discussed. Some of the beneficial adaptations exerted by RT include increased GLUT4 translocation in skeletal muscle, increased insulin sensitivity and hence restored metabolic flexibility. Increased energy expenditure and excess postexercise oxygen consumption in response to RT may be other beneficial effects. RT is increasingly establishing itself as an effective measure to improve overall metabolic health and reduce metabolic risk factors in diabetic patients.

Exercise lowers postprandial glucose but not fasting glucose in type 2 diabetes: a meta-analysis of studies using continuous glucose monitoring

Exercise has repeatedly been shown to improve glycemic control as assessed by glycated hemoglobin. However, changes in glycated hemoglobin do not provide information regarding which aspects of glycemic control have been altered. The purpose of this systematic review was to examine the effect of exercise as assessed by continuous glucose monitoring systems (CGMS) in type 2 diabetes. Databases (PubMed, Medline, EMBASE) were searched up to February 2013. Eligible studies had participants with type 2 diabetes complete standardized exercise protocols and used CGMS to measure changes in glycemic control. Randomized controlled trials, crossover trials and studies with pre-post designs were included. Average glucose concentration, daily time spent in hyperglycemia or hypoglycemia, and fasting glucose concentration were compared between exercise and control conditions. Eleven studies met the inclusion criteria and were included in the review. Eight studies had short-term (≤2 weeks) exercise interventions, whereas three studies had a longer-term intervention (all >2 months). The types of exercises utilized included aerobic, resistance and a combination of the two. The eight short-term studies were included in quantitative analysis. Exercise significantly decreased average glucose concentrations (-0.8 mmol/L, p < 0.01) and daily time spent in hyperglycemia (-129 minutes, p < 0.01), but did not significantly affect daily time spent in hypoglycemia (-3 minutes, p = 0.47) or fasting glucose (-0.3 mmol/L, p = 0.13). The four randomized crossover trials had similar findings compared to studies with pre-post designs. Exercise consistently reduced average glucose concentrations and time spent in hyperglycemia despite not significantly affecting outcomes such as fasting glucose and hypoglycemia.

An exercise prescription primer for people with depression

A substantial body of evidence supports the value of exercise in the treatment of people with depression. The guidelines for exercise prescription, however, are limited, and based on those developed for healthy populations. This article explores the evidence for exercise in the treatment of depression and the role mental health nurses may play in the delivery of this information. A model of exercise prescription is put forward based on the available evidence and taking into account the challenges faced by mental health nurses and people with depression.

Is cardiovascular or resistance exercise better to treat patients with depression? A narrative review

OBJECTIVES

There is growing evidence regarding the efficacy of exercise as a treatment strategy for patients with depression. This paper summarises the benefits of both cardiovascular and resistance exercise for patients with depression.

DESIGN

A narrative review design was employed. Supporting literature for the individual and combined benefits of both modalities are presented. Studies comparing both modalities are then discussed.

RESULTS

The outcomes of the review indicate that there is evidence for the efficacy of both cardiovascular exercise and resistance exercise, either independently or combined, in the treatment of depression across the range of severity levels and age groups.

CONCLUSION

Exercise interventions for the treatment of depression appear worthwhile and well tolerated. Exercise preference, access to resources and social support may shape the choice for the patient. The role of primary and allied health professionals in guiding this choice is discussed. Implications for clinical practice and further research are presented.

Exercise prescription in the treatment of type 2 diabetes mellitus : current practices, existing guidelines and future directions

Exercise is an effective treatment for type 2 diabetes mellitus, resulting in stabilization of plasma glucose in the acute phase and improvements in body composition, insulin resistance and glycosylated haemoglobin with chronic exercise training. However, the most appropriate exercise prescription for type 2 diabetes has not yet been established, resulting from insufficient evidence to determine the optimum type, intensity, duration or frequency of exercise training. Furthermore, patient engagement in exercise is suboptimal. There are many likely reasons for low engagement in exercise; one possible contributory factor may be a tendency for expert bodies to prioritize the roles of diet and medication over exercise in their treatment guidelines. Published treatment guidelines vary in their approach to exercise training, but most agencies suggest that people with type 2 diabetes engage in 150 min of moderate to vigorous aerobic exercise per week. This prescription is similar to the established guidelines for cardiovascular health in the general population. Future possibilities in this area include investigation of the physiological effects and practical benefits of exercise training of different intensities in type 2 diabetes, and the use of individualized prescription to maximize the health benefits of training.

Resistance training decreases serum inflammatory markers in diabetic rats

Inflammation plays an important role in the genesis and progression of diabetes. The purpose of this study was to investigate the effect of resistance training on serum levels of some inflammatory markers associated with diabetes mellitus. Twenty-four male Wistar rats (290 ± 19 g) were randomly divided into three groups: non-diabetic control (non-DC), diabetic control (DC), and diabetic trained (DT). Animals in DT group were subjected to a resistance training program with the use of a ladder (3 days/week, for 4 weeks). Body weight, serum high sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, tumor necrosis factor (TNF)-α, fasting glucose, and insulin were measured. Four weeks of resistance training decreased serum levels of TNF-α, hs-CRP, and IL-6 in diabetic rats when compared with DC animals. We conclude that resistance training with appropriate intensity, duration, and recovery between exercise bouts has marked anti-inflammatory effects on diabetic rats. This may be an efficient strategy to protect against some diabetic complications.

Physical activity in obesity and metabolic syndrome

Biological aging is typically associated with a progressive increase in body fat mass and a loss of lean body mass. Owing to the metabolic consequences of reduced muscle mass, it is understood that normal aging and/or decreased physical activity may lead to a higher prevalence of metabolic disorders. Lifestyle modification, specifically changes in diet, physical activity, and exercise, is considered the cornerstone of obesity management. However, for most overweight people it is difficult to lose weight permanently through diet or exercise. Thus, prevention of weight gain is thought to be more effective than weight loss in reducing obesity rates. A key question is whether physical activity can extenuate age-related weight gain and promote metabolic health in adults. Current guidelines suggest that adults should accumulate about 60 minutes of moderate-intensity physical activity daily to prevent unhealthy weight gain. 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 better metabolic control.

The impact of brief high-intensity exercise on blood glucose levels

BACKGROUND

Moderate-intensity exercise improves blood glucose (BG), but most people fail to achieve the required exercise volume. High-intensity exercise (HIE) protocols vary. Maximal cycle ergometer sprint interval training typically requires only 2.5 minutes of HIE and a total training time commitment (including rest and warm up) of 25 minutes per session. The effect of brief high-intensity exercise on blood glucose levels of people with and without diabetes is reviewed.

METHODS

HIE (≥80% maximal oxygen uptake, VO2max) studies with ≤15 minutes HIE per session were reviewed.

RESULTS

Six studies of nondiabetics (51 males, 14 females) requiring 7.5 to 20 minutes/week of HIE are reviewed. Two weeks of sprint interval training increased insulin sensitivity up to 3 days postintervention. Twelve weeks near maximal interval running (total exercise time 40 minutes/week) improved BG to a similar extent as running at 65% VO2max for 150 minutes/week. Eight studies of diabetics (41 type 1 and 22 type 2 subjects) were reviewed. Six were of a single exercise session with 44 seconds to 13 minutes of HIE, and the others were 2 and 7 weeks duration with 20 and 2 minutes/week HIE, respectively. With type 1 and 2 diabetes, BG was generally higher during and up to 2 hours after HIE compared to controls. With type 1 diabetics, BG decreased from midnight to 6 AM following HIE the previous morning. With type 2 diabetes, a single session improved postprandial BG for 24 hours, while a 2-week program reduced the average BG by 13% at 48 to 72 hours after exercise and also increased GLUT4 by 369%.

CONCLUSION

Very brief HIE improves BG 1 to 3 days postexercise in both diabetics and non-diabetics. HIE is unlikely to cause hypoglycemia during and immediately after exercise. Larger and longer randomized studies are needed to determine the safety, acceptability, long-term efficacy, and optimal exercise intensity and duration.

Therapeutic Chinese exercises (Qigong) in the treatment of type 2 diabetes mellitus: a systematic review

STATEMENT OF THE PROBLEM

Complementary and alternative medicines have been increasingly used as a co adjuvant treatment of chronic diseases, including diabetes mellitus. However, very little is known, especially in western countries, about its effects in the treatment of type 2 diabetes mellitus (T2DM). The purpose of this review was to summarize and critically evaluate clinical evidences regarding the effect of Chinese therapeutic exercises (Qigong) in the treatment of T2DM.

METHODS

A systematic literature review, from January 1992 up to July 2011, searched articles indexed in the MEDLINE, LILACS and QIGONG databases, published in English and Portuguese. Terms combined in a Boolean search were "Qigong", "Chikung" "qi-gong" "diabetes" and "glycemic control". Risk of bias was assessed using the Cochrane criteria.

RESULTS

Out of 30 English written articles, 5 studies met the inclusion criteria. Their results suggested favorable effects of Qigong in reducing C-peptide and fasting blood glucose levels in addition of improving insulin resistance and glycosilated hemoglobin.

CONCLUSIONS

The few studies, written in English, available on this subject had a somewhat limited methodological quality preventing definitive conclusions about the efficacy of Qigong Chinese exercises in the treatment of type 2 diabetes mellitus. There is a need of large randomized clinical trials to prove the effectiveness of this modality of therapy, as well as the need for more research papers written in English in order to disseminate and expand the potential benefit of this therapy in the management of T2DM.

Exercise and type 2 diabetes: new prescription for an old problem

During the past 50 years, the prevalence of a cluster of chronic, inactivity-related diseases including obesity, insulin resistance and type 2 diabetes mellitus (T2DM), collectively referred to as 'metabolic syndrome' (MetS) has reached global epidemic proportions. Appropriate exercise training is a clinically proven, cost-effective, primary intervention that delays and in many cases prevents the health burdens associated with MetS. Indeed, there is no single intervention with greater efficacy than physical exercise to reduce the risk of virtually all chronic diseases simultaneously. However compliance to National guidelines for physical activity remains low, with "a lack of time" the most frequently cited barrier to exercise participation by adults, irrespective of age, sex and ethnic background. Part of the growing apathy to modify lifestyle habits is that current public health recommendations may be unrealistic and unattainable for the majority of the populace. Hence, there is an urgent need for innovations in exercise prescription that can be incorporated into daily living and induce clinically beneficial health outcomes. Here we focus attention on a novel form of exercise prescription, high-intensity interval training (HIT), and provide evidence that HIT is a time-efficient and well-tolerated therapeutic intervention to improve cardio-metabolic health in a number of pre-clinical and clinical populations.

Efeito do treinamento combinado e aeróbio no controle glicêmico no diabetes tipo 2

INTRODUÇÃO: O diabetes tipo 2 é um grupo heterogêneo de doença metabólica causada por uma disfunção na secreção da insulina e/ou ação desta. OBJETIVOS: Comparar o efeito de duas modalidades de treinamento, o combinado (aeróbio e resistido) e o aeróbio, no controle glicêmico no diabetes tipo 2. MATERIAIS E MÉTODOS: A pesquisa caracteriza-se por ser um estudo quase-experimental. Após aprovação do CEP, com registro 09.071.4.08. III, deu-se início ao programa de treinamento combinado e aeróbio. Foram selecionados 24 participantes, de ambos os gêneros, sedentários, com média de idade de 60,41 ± 7,87. Os participantes foram divididos aleatoriamente em dois grupos: treinamento combinado (n = 12) e treinamento aeróbio (n = 12); ambos foram avaliados no início e final do estudo. A concentração sérica de glicose foi determinada pelo sistema Vitros e a hemoglobina glicosilada foi determinada pelo método Cromatografia Líquida de Alta Performance. O treinamento foi realizado três vezes por semana, com duração total de 20 semanas. Os dados são expressos em média e desvio-padrão. Foi aplicado o teste t pareado (p < 0,05) para comparar a média basal e após 20 semanas de treinamento. RESULTADOS: A média da glicose em jejum do treinamento combinado reduziu significativamente, de 167,41 ± 38,13 para 119,83 ± 20,91, sendo que o mesmo ocorreu com o treinamento aeróbio de 189,83 ± 63,57 para 139,91 ± 34,04. Os valores da hemoglobina glicosilada no treinamento combinado e treinamento aeróbio reduziram significativamente, de 8,61 ± 1,17 para 7,25 ± 1,24 e de 9,52 ± 2,46 para 8,37 ± 1,50, respectivamente. CONCLUSÃO: O treinamento combinado foi mais eficaz em relação à hemoglobina glicosilada e o treinamento aeróbio, na glicose plasmática.

Major, non-chromosomal, birth defects and maternal physical activity: a systematic review

BACKGROUND

We reviewed the published literature to assess the association between maternal periconceptional physical activity and the risk for major, non-chromosomal, birth defects and whether this varies by pre-pregnancy obesity.

METHODS

We conducted a systematic literature search of MEDLINE, EMBASE, and CINAHL databases. Data were abstracted from all articles that met our inclusion criteria and included information on physical activity intensity (mild, moderate, and vigorous) and modality (i.e., standing, lifting, other). We assessed occupational and recreational physical activity separately. The quality of included articles was assessed using the Newcastle-Ottawa Scale.

RESULTS

Of 3316 screened articles, 11 were included in this review. Of the four studies that assessed prolonged standing, two reported a positive association with risk for some birth defects; null associations were observed in the other two studies. Associations between heavy lifting or other occupational physical activity exposures and risk for birth defects were inconsistent. A protective association between leisure-time physical activity (i.e., active sports, swimming) and some birth defects (e.g., neural tube defects), was suggested by the results of two studies. Only one study reported assessment of possible effect modification by maternal body mass index (BMI).

DISCUSSION

Our review suggests that there may be some associations between occupational and leisure-time physical activities and some, major non-chromosomal, birth defects, but relatively limited published research exists on these associations. Further research in this area should include differentiation of birth defects phenotypes, valid assessments of all domains of physical activity, including household and transportation activity, and account for the potential influence of pre-pregnancy BMI.