Glycemic and Metabolic Effects of Two Long Bouts of Moderate-Intensity Exercise in Men with Normal Glucose Tolerance or Type 2 Diabetes

The Influence of Acute and Chronic Exercise on Appetite and Appetite Regulation in Patients with Prediabetes or Type 2 Diabetes Mellitus-A Systematic Review

This systematic review aims to analyze the effects of acute and chronic exercise on appetite and appetite regulation in patients with abnormal glycemic control. PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials were searched for eligible studies. The included studies had to report assessments of appetite (primary outcome). Levels of appetite-regulating hormones were analyzed as secondary outcomes (considered, if additionally reported). Seven studies with a total number of 211 patients with prediabetes or type 2 diabetes mellitus (T2DM) met the inclusion criteria. Ratings of hunger, satiety, fullness, prospective food consumption, nausea, and desire to eat, as well as levels of (des-)acylated ghrelin, glucagon-like peptide 1, glucose-dependent insulinotropic peptide, pancreatic polypeptide, peptide tyrosine tyrosine, leptin, and spexin were considered. Following acute exercise, the effects on appetite (measured up to one day post-exercise) varied, while there were either no changes or a decrease in appetite ratings following chronic exercise, both compared to control conditions (without exercise). These results were accompanied by inconsistent changes in appetite-regulating hormone levels. The overall risk of bias was low. The present results provide more evidence for an appetite-reducing rather than an appetite-increasing effect of (chronic) exercise on patients with prediabetes or T2DM. PROSPERO ID: CRD42023459322.

Neuromuscular electrical stimulation changes glucose, but not its variability in type 2 diabetes: a randomized clinical trial

Neuromuscular electrical stimulation (NMES) can be an alternative to conventional exercising. This randomized clinical trial evaluated the effect of NMES in type 2 diabetes patients. Twenty-eight individuals with type 2 diabetes were assigned to NMES (n=14) or NMES-placebo (n=14) applied to knee extensor muscles for 60 minutes. Glucose variability, microvascular function and endothelial function were evaluated through continuous glucose monitoring system, near infrared spectroscopy and flow-mediated dilatation, respectively. Glucose levels (mg/dl) decreased 2h (184 ± 11 vs 223 ±15), 3h (179 ± 12 vs 219 ±14) and 4h (177 ± 12 vs 212 ±12) after NMES, in comparison to NMES-placebo. No differences in glucose variability were found: coefficient of variation (%) at 0-6h (11.4±1.3 vs 11.4±1.2), 6-12h (9.8±1.0 vs 11.6±1.6), 12-18h (15.5±2.0 vs 11.4±2.1), 18-24h (12.8±2.3 vs 10.0±1.6); standard deviation (mg/dl) at 0-6h (21.6±2 vs 24.6±3.5), 6-12h (19.5±1.8 vs 20.3±2.8), 12-18h (29.9±3.5 vs 21.3±2.8),18-24h (22.8±4.1 vs 16.6±2.0) and mean amplitude of glycemic excursions (mg/dl) 54.9±25.0 vs 70.3±35.7. Endothelial and microvascular functions did not change. In conclusion, one acute NMES session was strong enough to trigger glucose reduction in individuals with type 2 DM, but it failed to induce any significant change in glucose variability, endothelial and microvascular functions.

Maintenance of plasma glucose variability after an acute session of aerobic exercise despite changes in insulin and glucagon-like peptide-1 levels in type 2 diabetes

Objective

The present study aimed to evaluate glucose variability and hormonal responses during and after an aerobic exercise session performed after breakfast in type 2 diabetes patients treated with metformin.

Methods

In this quasi-experimental study individuals underwent clinical and laboratory evaluations and maximal exercise test. After two weeks an aerobic exercise session (30 minutes at 60%-70% of the peak heart rate) was performed. At rest, during and after the exercise session, glucose variability (mean amplitude glucose excursions, glucose coefficient of variation, and glucose standard deviation) and levels of plasma glucose, insulin, glucagon, and glucagon-like-peptide-1 were evaluated.

Results

Thirteen patients were enrolled in the study. Plasma glucose increased at 15 minutes during the exercise session (244.6 ± 61.9 mg/dL), and decreased at 60 min after exercise (195.6 ± 50.0 mg/dL). Glucose variability did not show any difference before and after exercise. Insulin levels at 15 min [27.1 μU/mL (14.2-42.1)] and 30 min [26.3 μU/mL (14.6-37.4)] during the exercise were higher than those at fasting [11.2 μU/mL (6.7-14.9)] but decreased 60 minutes after exercise (90 minutes) [16.6 μU/mL (8.7-31.7)]. Glucagon levels did not show any difference. GLP-1 levels increased at 30 min [7.9 pmol/L (7.1-9.2)] during exercise and decreased 60 min after exercise (90 minutes) [7.7 pmol/L (6.8-8.5)].

Conclusion

Subjects with type 2 diabetes presented expected changes in insulin, glucagon and GLP-1 levels after breakfast and a single aerobic exercise session, not accompanied by glycemic variability changes.

Effect of 6 weeks of very low-volume high-intensity interval training on oral glucose-stimulated incretin hormone response

Introduction: Decreased fasting and oral glucose-stimulated incretin hormone concentrations following moderate-intensity continuous endurance training interventions have been reported in glucose-tolerant people, however results are conflicting. The effect of more time-efficient, very low-volume, high-intensity interval training (HIT) on circulating incretin hormone levels has never been studied.Materials and methods: Ten sedentary and overweight-to-obese participants (4 women and 6 men; age 43 ± 6 years (mean ± SD); BMI 30.2 ± 3.2 kg∙m^-2; HbA1c 35 ± 5.1 mmol∙mol^-1 (5.3 ± 0.3%); VO₂max 30 ± 5 ml∙min^-1∙kg^-1) from the Copenhagen cohort of the METAPREDICT trial underwent 6 weeks of supervised low-volume HIT (3 sessions per week: 7 × 1 min at ∼100% VO₂max separated by 1 min of active recovery). We measured glucose, insulin, C-peptide, glucagon, GLP-1 and GIP concentrations during a frequently sampled 75 g oral glucose tolerance test as well as VO₂max and body composition before and after the intervention.Results: Training compliance was 100%. Relative VO₂max improved after the intervention (median 2.69 ml∙min^-1∙kg^-1, IQR [0.43; 3.14], p = 0.037) while there were no significant effects on body weight and composition. No significant effects on oral glucose-stimulated glucose and hormone responses or estimates of insulin sensitivity and β-cell function were observed.Conclusion: Low-volume HIT improved aerobic fitness, but neither affected glucose tolerance nor oral glucose-stimulated incretin hormone responses in sedentary and overweight-to-obese people.Highlights Ten sedentary, overweight-to-obese, glucose-tolerant participants underwent 6 weeks of supervised, very low-volume HIT.Aerobic fitness improved.Fasting and oral glucose-stimulated incretin hormone concentrations were not affected.

Relationship between diet/exercise and pharmacotherapy to enhance the GLP-1 levels in type 2 diabetes

The rapid rise in the prevalence of type 2 diabetes mellitus (T2DM) poses a huge healthcare burden across the world. Although there are several antihyperglycaemic agents (AHAs) available including addition of new drug classes to the treatment algorithm, more than 50% of patients with T2DM do not achieve glycaemic targets, suggesting an urgent need for treatment strategies focusing on prevention and progression of T2DM and its long-term complications. Lifestyle changes including implementation of healthy diet and physical activity are cornerstones for the management of T2DM. The positive effects of diet and exercise on incretin hormones such as glucagon-like peptide-1 (GLP-1) have been reported. We hypothesize an IDEP concept (Interaction between Diet/Exercise and Pharmacotherapy) aimed at modifying the diet and lifestyle, along with pharmacotherapy to enhance the GLP-1 levels, would result in good glycaemic control in patients with T2DM. Consuming protein-rich food, avoiding saturated fatty acids and making small changes in eating habits such as eating slowly with longer mastication time can have a positive impact on the GLP-1 secretion and insulin levels. Further the type of physical activity (aerobic/resistance training), intensity of exercise, duration, time and frequency of exercise have shown to improve GLP-1 levels. Apart from AHAs, a few antihypertensive drugs and lipid-lowering drugs have also shown to increase endogenous GLP-1 levels, however, due to quick degradation of GLP-1 by dipeptidyl peptidase-4 (DPP-4) enzyme, treatment with DPP-4 inhibitors would protect GLP-1 from degradation and prolong its activity. Thus, IDEP concept can be a promising treatment strategy, which positively influences the GLP-1 levels and provide additive benefits in terms of improving metabolic parameters in patients with T2DM and slowing the progression of T2DM and its associated complications.