Glycemic control with physical training in insulin-dependent diabetes mellitus

Cardiovascular Health Benefits of Exercise Training in Persons Living with Type 1 Diabetes: A Systematic Review and Meta-Analysis

Exercise is advocated in the management of type 1 diabetes (T1D), but the effects of different forms of exercise training on cardiovascular risk factors in T1D still remain unclear. The aim of this study was to conduct a systematic review and meta-analysis on exercise training for cardiovascular risk factors in T1D. Six electronic databases were systematically searched for randomized or non-randomized controlled studies reporting associations between exercise training and cardiovascular risk factors in T1D. Weighted mean differences (WMD) of each cardiovascular risk factor between exercise groups and control groups were calculated using a random effects model. A total of 24 studies reported the effects of exercise training on cardiovascular risk factors. Exercise training increased maximal aerobic power (3.01 mL·kg⁻¹·min⁻¹, 95% confidence interval, CI, 0.94 to 6.38) and reduced glycated hemoglobin (HbA1c; −0.45%, 95% CI −0.73 to −0.17), daily insulin dosage (−0.88 U·kg⁻¹, 95% CI −1.27 to −0.48), and total cholesterol (−0.38 mmol·L⁻¹, 95% CI −0.71 to −0.04). Exercise training did not lead to consistent changes in body mass index (BMI), blood pressure, triglycerides, high-density lipoprotein cholesterol (HDL-C), or low-density lipoprotein cholesterol (LDL-C). In persons living with T1D, exercise training is associated with a beneficial cardiovascular profile, including improvements in lipid profile, glycemic control (decreased daily insulin dosage and HbA1c), and aerobic fitness.

Physical Activity in Youth With Type 1 Diabetes: a Review

Youth with type 1 diabetes are at risk for developing cardiovascular disease, and regular physical activity is strongly recommended as one strategy for prevention, as well as for good glycemic control. Despite recommendations, families in this pediatric population face unique barriers to physical activity, including fear of hypoglycemia. Moreover, families are not routinely counseled in the specific health and psychosocial benefits of following physical activity recommendations for youth with type 1 diabetes. To bridge this gap, the recent literature regarding physical activity in children with type 1 diabetes is reviewed with particular focus on young children. A discussion of the limitations of the current body of research, and recommendations for objectively measured physical activity are provided. Specific recommendations for clinical practice are given, including provider endorsements for regular physical activity for longer than 60 minutes, at least three times a week.

Physical activity interventions in children and young people with Type 1 diabetes mellitus: a systematic review with meta-analysis

AIMS

To synthesize evidence from randomized and non-randomized studies of physical activity interventions in children and young people with Type 1 diabetes so as to explore clinically relevant health outcomes and inform the promotion of physical activity.

METHOD

We conducted a search of CINAHL Plus, the Cochrane Library, EMBASE, MEDLINE, PsycINFO, SCOPUS, SportDiscus and Web of Science between October and December 2012. Eligible articles included subjects aged ≤18 years with Type 1 diabetes and a physical activity intervention that was more than a one-off activity session. Physiological, psychological, behavioural or social outcomes were those of interest.

RESULTS

A total of 26 articles (10 randomized and 16 non-randomized studies), published in the period 1964-2012, were reviewed. Although there was heterogeneity in study design, methods and reporting, 23 articles reported at least one significant beneficial health outcome at follow-up. Meta-analyses of these studies showed potential benefits of physical activity on HbA1c (11 studies, 345 participants, standardized mean difference -0.52, 95% CI -0.97 to -0.07; P = 0.02), BMI (four studies, 195 participants, standardized mean difference -0.41, 95% CI -0.70 to -0.12; P = 0.006) and triglycerides (five studies, 206 participants, standardized mean difference -0.70, 95% CI -1.25 to -0.14; P = 0.01).The largest effect size was for total cholesterol (five studies, 206 participants, standardized mean difference -0.91, 95% CI -1.66 to -0.17; P = 0.02).

CONCLUSIONS

Physical activity is important for diabetes management and has the potential to delay cardiovascular disease, but there is a lack of studies that are underpinned by psychological behaviour change theory, promoting sustained physical activity and exploring psychological outcomes. There remains a lack of knowledge of how to promote physical activity in people with Type 1 diabetes.

Effects of different types of acute and chronic (training) exercise on glycaemic control in type 1 diabetes mellitus: a meta-analysis

OBJECTIVE

Exercise has been accepted and generally recommended for the management of type 1 diabetes mellitus (T1D) and for improving the overall quality of life in affected individuals. This meta-analysis was conducted to determine the overall effects of exercise (acute bouts of exercise and chronic exercise [or training]) on acute and chronic glycaemic control in patients with T1D, the effects of different types of exercise on glycaemic control and which conditions are required to obtain these positive effects.

METHODS

PubMed, ISI Web of Knowledge and SPORTDiscus™ were consulted to identify studies on T1D and exercise. Cohen's d statistics were used for calculating mean effect sizes (ES) as follows: small d = 0.3, medium d = 0.5 and large d = 0.8. Ninety-five percent confidence intervals (95% CIs) were used to establish the significance of our findings.

RESULTS

From a total of 937 studies, 33 that met the inclusion criteria were selected. Nine studies were used to calculate the ES of a single bout of aerobic exercise; 13 studies to calculate the ES of aerobic training; 2 studies to calculate the ES of strength training; 4 studies to calculate the ES of combined (aerobic and strength) training and 6 studies to calculate the ES of high-intensity exercise (HIE) and training. ES for exercise on acute glycaemic control were large, while they were small for chronic glycaemic control. Aerobic exercise, resistance exercise, mixed exercise (aerobic combined with resistance training) and HIE acutely decreased blood glucose levels. To prevent late-onset hypoglycaemic episodes, the use of single bouts of sprints into an aerobic exercise can be recommended. This meta-analysis also showed that a regular exercise training programme has a significant effect on acute and chronic glycaemic control, although not all exercise forms showed significant results. Specifically, aerobic training is a favourable tool for decreasing chronic glycaemic control, while resistance training, mixed and HIE did not significantly improve chronic glycaemic control. Although, this meta-analysis showed there was a tendency for improvement in glycaemic control due to resistance training or resistance training combined with endurance training, there were not enough studies and/or subjects to confirm this statistically.

CONCLUSIONS

Based on this meta-analysis, we can conclude that the addition of brief bouts of high-intensity, sprint-type exercise to aerobic exercise can minimize the risk of sustaining a hypoglycaemic episode. We can also conclude that only regular aerobic training will improve the glycated haemoglobin level of a patient with T1D.

Effects of different types of acute and chronic (training) exercise on glycaemic control in type 1 diabetes mellitus: a meta-analysis

OBJECTIVE

Exercise has been accepted and generally recommended for the management of type 1 diabetes mellitus (T1D) and for improving the overall quality of life in affected individuals. This meta-analysis was conducted to determine the overall effects of exercise (acute bouts of exercise and chronic exercise [or training]) on acute and chronic glycaemic control in patients with T1D, the effects of different types of exercise on glycaemic control and which conditions are required to obtain these positive effects.

METHODS

PubMed, ISI Web of Knowledge and SPORTDiscus™ were consulted to identify studies on T1D and exercise. Cohen's d statistics were used for calculating mean effect sizes (ES) as follows: small d = 0.3, medium d = 0.5 and large d = 0.8. Ninety-five percent confidence intervals (95% CIs) were used to establish the significance of our findings.

RESULTS

From a total of 937 studies, 33 that met the inclusion criteria were selected. Nine studies were used to calculate the ES of a single bout of aerobic exercise; 13 studies to calculate the ES of aerobic training; 2 studies to calculate the ES of strength training; 4 studies to calculate the ES of combined (aerobic and strength) training and 6 studies to calculate the ES of high-intensity exercise (HIE) and training. ES for exercise on acute glycaemic control were large, while they were small for chronic glycaemic control. Aerobic exercise, resistance exercise, mixed exercise (aerobic combined with resistance training) and HIE acutely decreased blood glucose levels. To prevent late-onset hypoglycaemic episodes, the use of single bouts of sprints into an aerobic exercise can be recommended. This meta-analysis also showed that a regular exercise training programme has a significant effect on acute and chronic glycaemic control, although not all exercise forms showed significant results. Specifically, aerobic training is a favourable tool for decreasing chronic glycaemic control, while resistance training, mixed and HIE did not significantly improve chronic glycaemic control. Although, this meta-analysis showed there was a tendency for improvement in glycaemic control due to resistance training or resistance training combined with endurance training, there were not enough studies and/or subjects to confirm this statistically.

CONCLUSIONS

Based on this meta-analysis, we can conclude that the addition of brief bouts of high-intensity, sprint-type exercise to aerobic exercise can minimize the risk of sustaining a hypoglycaemic episode. We can also conclude that only regular aerobic training will improve the glycated haemoglobin level of a patient with T1D.

Atherosclerosis in childhood and adolescent type 1 diabetes: early disease, early treatment?

Autopsy studies have shown that atherosclerosis begins in adolescence in otherwise healthy individuals, and imaging techniques have shown that atherosclerosis develops earlier and is more prevalent in children with diabetes than in age-matched healthy controls. Cardiovascular disease has now overtaken diabetic nephropathy as the leading cause of premature mortality in young adults with diabetes, and the emphasis on disease prevention has accordingly shifted to a younger age group. The majority of children and adolescents with diabetes have suboptimal blood glucose control, and this contributes to accelerated arterial disease in this age group. Other conventional risk factors for coronary heart disease also need to be considered and treated aggressively. Effective early prevention of cardiovascular disease will involve lifestyle modification and full implementation of existing treatment guidelines, and large-scale prospective studies will be needed to establish the risks and benefits of early pharmacological intervention in children and adolescents.

Leisure time physical activity is associated with poor glycemic control in type 1 diabetic women: the FinnDiane study

OBJECTIVE

We studied the association between leisure time physical activity (LTPA) and glycemic control, insulin dose, and estimated glucose disposal rate (eGDR) in type 1 diabetes.

RESEARCH DESIGN AND METHODS

This is a cross-sectional study of 1,030 type 1 diabetic patients participating in the Finnish Diabetic Nephropathy Study, a nationwide multicenter study. LTPA was assessed by a validated 12-month questionnaire and expressed in metabolic equivalent (MET) units. Patients were grouped as sedentary (LTPA <10 MET h/week, n = 247), moderately active (LTPA 10-40 MET h/week, n = 568), and active (LTPA >40 MET h/week, n = 215). Outcome measures were HbA(1c), insulin dose, and eGDR (estimate of insulin sensitivity based on waist-to-hip ratio, hypertension, and HbA(1c)).

RESULTS

LTPA correlated with HbA(1c) in women (r = -0.12, P = 0.007) but not in men (r = -0.03, P = 0.592). Sedentary women had higher HbA(1c) than moderately active and active women: 8.8 +/- 1.4% vs. 8.3 +/- 1.4% vs. 8.3 +/- 1.4% (P = 0.004), whereas HbA(1c) in men was 8.4 +/- 1.3% vs. 8.2 +/- 1.4% vs. 8.2 +/- 1.3% (P = 0.774), respectively. In men, insulin doses were 0.74 +/- 0.21 vs. 0.71 +/- 0.20 vs. 0.68 +/- 0.23 IU . kg(-1) . 24 h(-1) (P = 0.003). In both sexes, sedentary patients had lower eGDRs than active patients [median (interquartile range) 5.5 (4.0-8.2) vs. 6.8 (4.7-8.8) vs. 6.7 (4.6-8.6) mg . kg(-1) . min(-1); P < 0.01 for sedentary vs. others]. Age, obesity, smoking, insulin dose, social class, diabetic nephropathy, or cardiovascular disease did not explain the results.

CONCLUSIONS

Low levels of LTPA were associated with poor glycemic control in type 1 diabetic women. Men seem to use less insulin when physically active. Increased LTPA levels were associated with increased estimated insulin sensitivity. Longitudinal studies are needed to further clarify the effects of LTPA on type 1 diabetes.