Short-term aerobic exercise training improves gut peptide regulation in nonalcoholic fatty liver disease

Liraglutide combined with HIIT preserves contractile apparatus and blunts the progression of heart failure in diabetic cardiomyopathy rats

Liraglutide has been shown to alleviate heart failure in patients with type 2 diabetes. High-intensity interval training (HIIT) has also been proven to improve cardiac function in diabetes. The present study explored the effects and underlying mechanisms of liraglutide and HIIT combination therapy in alleviating diabetic cardiomyopathy (DCM). A high-fat diet and low-dose streptozotocin (STZ) were utilized to induce the DCM model. Eight weeks of liraglutide injection and HIIT were used to treat DCM. Subsequently, cardiac function, serum metabolic biomarkers, serum glucagon-like peptide-1 (GLP-1), histology examination, cardiac alpha-myosin heavy chain (α-MHC), and β-MHC messenger RNA (mRNA) expression, forkhead box protein O1 (FOXO1) and muscle-specific RING finger protein 1 (MURF1) mRNA expression and colocalization, and expression of GLP-1 and GLP-1 receptor (GLP-1R) proteins were detected after the intervention. Results showed that DCM rats developed hyperglycemia with eccentric hypertrophy, fibrosis, and reduced systolic and diastolic function. All interventions significantly reversed the development of heart failure by alleviating the disruption of contractile apparatus, reversed the adult α-MHC transformed to fetal β-MHC, and reduced FOXO1 and MURF1 mRNA expression. Combination therapy had a better effect in alleviating cardiac fibrosis, reducing cardiovascular risk biomarkers, controlling eccentric hypertrophy, and improving systolic function. Combination therapy significantly reduced FOXO1 and MURF1 colocalization and improved the GLP-1R sensitivity in diabetic hearts. Overall, these findings demonstrate that combination therapy can reverse cardiac failure in diabetic rats by controlling the degradation of contractile apparatus by downregulating the cardiac atrophy gene expression and interrupting their colocalization, as well as upregulating GLP-1 signaling.

The Role of Exercise in Steatotic Liver Diseases: An Updated Perspective

BACKGROUND

The increasing prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), parallels the rise in sedentary lifestyles. MASLD is the most common form of steatotic liver disease (SLD), which represents the umbrella beneath which the vast majority of chronic liver diseases fall, including alcohol-related liver disease and their overlap. These conditions are the leading contributors to chronic liver disease, significantly impacting global morbidity and mortality. Despite the emergence of new pharmacotherapies, exercise represents the foundation of MASLD treatment.

OBJECTIVE

This review aims to provide an updated perspective on the role of exercise in the management of SLD, highlight its molecular and clinical benefits, and explore its benefits and safety in the stage of cirrhosis.

METHODS

Evidence from pre-clinical and clinical studies was reviewed to evaluate the impact of exercise on SLD (mainly MASLD), advanced chronic liver disease stages, and its relevance in the context of evolving therapies such as Resmetirom and incretin-based anti-obesity medications.

CONCLUSION

Exercise remains a cornerstone intervention in the management of MASLD, with suggested benefits even for patients who have progressed to cirrhosis. Personalized exercise regimens should be prioritized for all patients, including those receiving pharmacotherapy. Further research is needed to refine exercise protocols and investigate their impact on histologic and clinical outcomes, as well as their potential synergistic effects with emerging treatments.

A new perspective in intestinal microecology: lifting the veil of exercise regulation of cardiometabolic diseases

Cardiometabolic diseases (CMDs), encompassing cardiovascular and metabolic dysfunctions, characterized by insulin resistance, dyslipidemia, hepatic steatosis, and inflammation, have been identified with boosting morbidity and mortality due to the dearth of efficacious therapeutic interventions. In recent years, studies have shown that variations in gut microbiota and its own metabolites can influence the occurrence of CMDs. Intriguingly, the composition and function of the gut microbiota are susceptible to exercise patterns, thus affecting inflammatory, immune, and metabolic responses within the host. In this review, we introduce the key mechanisms of intestinal microecology involved in the onset and development of CMDs, discuss the relationship between exercise and intestinal microecology, and then analyze the role of intestinal microecology in the beneficial effects of exercise on CMDs, aiming at elucidating the gut-heart axis mechanisms of exercise mediated protective effect on CMDs, building avenues for the application of exercise in the management of CMDs.

The Effects of a Short-Term Combined Exercise Program on Liver Steatosis Indices and the Lipidemic and Glycemic Profile in NAFLD Individuals: A Pilot Study

Non-alcoholic fatty liver disease (NAFLD) is a very common liver disease associated with obesity, unhealthy diet, and lack of physical exercise. Short-term aerobic or resistance exercise has been shown to result in reduced liver fat in patients with NAFLD; however, the impact of the combination of these types of exercise has received less attention. This study investigated the effect of a short-term (7 days) concurrent exercise training program performed daily on liver steatosis indices, as well as the glycemic and lipidemic profile of overweight/obese sedentary volunteers. Twenty adult patients (age: 47.3 ± 12.3 yrs, body mass index: 32.4 ± 3.4 kg/m2) with NAFLD, detected by ultrasound and hematological indices, participated in the study. Pre- and post-exercise intervention assessment included body weight (BW), waist circumference (WC), hip/waist ratio (H/W), Homeostasis Model Assessment Insulin Resistance (HOMA-IR), blood lipids, and steatosis indices. Fatty Liver Index, Lipid Accumulation Index, WC, H/W, triglycerides, and total cholesterol were improved (p < 0.05) post-exercise, while no differences (p > 0.05) were observed in BW, HOMA-IR, HDL, LDL, Hepatic Steatosis Index, and Framingham Steatosis Index compared to pre-exercise values. It is concluded that a 7-day combined exercise program can have beneficial effects on hepatic steatosis and central adiposity indices, independently of weight loss, in patients with NAFLD.

Exercise Is Medicine for Nonalcoholic Fatty Liver Disease: Exploration of Putative Mechanisms

Exercise remains a key component of nonalcoholic fatty liver disease (NAFLD) treatment. The mechanisms that underpin improvements in NAFLD remain the focus of much exploration in our attempt to better understand how exercise benefits patients with NAFLD. In this review, we summarize the available scientific literature in terms of mechanistic studies which explore the role of exercise training in modulating fatty acid metabolism, reducing hepatic inflammation, and improving liver fibrosis. This review highlights that beyond simple energy expenditure, the activation of key receptors and pathways may influence the degree of NAFLD-related improvements with some pathways being sensitive to exercise type, intensity, and volume. Importantly, each therapeutic target of exercise training in this review is also the focus of previous or ongoing drug development studies in patients with nonalcoholic steatohepatitis (NASH), and even when a regulatory-agency-approved drug comes to market, exercise will likely remain an integral component in the clinical management of patients with NAFLD and NASH.

Exercise in the Prevention and Treatment of Type 2 Diabetes

Type 2 diabetes is a systemic, multifactorial disease that is a leading cause of morbidity and mortality globally. Despite a rise in the number of available medications and treatments available for management, exercise remains a first-line prevention and intervention strategy due to established safety, efficacy, and tolerability in the general population. Herein we review the predisposing risk factors for, prevention, pathophysiology, and treatment of type 2 diabetes. We emphasize key cellular and molecular adaptive processes that provide insight into our evolving understanding of how, when, and what types of exercise may improve glycemic control. © 2023 American Physiological Society. Compr Physiol 13:1-27, 2023.

The role of exercise and hypoxia on glucose transport and regulation

Muscle glucose transport activity increases with an acute bout of exercise, a process that is accomplished by the translocation of glucose transporters to the plasma membrane. This process remains intact in the skeletal muscle of individuals with insulin resistance and type 2 diabetes mellitus (T2DM). Exercise training is, therefore, an important cornerstone in the management of individuals with T2DM. However, the acute systemic glucose responses to carbohydrate ingestion are often augmented during the early recovery period from exercise, despite increased glucose uptake into skeletal muscle. Accordingly, the first aim of this review is to summarize the knowledge associated with insulin action and glucose uptake in skeletal muscle and apply these to explain the disparate responses between systemic and localized glucose responses post-exercise. Herein, the importance of muscle glycogen depletion and the key glucoregulatory hormones will be discussed. Glucose uptake can also be stimulated independently by hypoxia; therefore, hypoxic training presents as an emerging method for enhancing the effects of exercise on glucose regulation. Thus, the second aim of this review is to discuss the potential for systemic hypoxia to enhance the effects of exercise on glucose regulation.

Physical exercise promotes memory function in diabetes mellitus rats: a look at glucagon like peptide-1 and glucagon like peptide-1 receptor

Diabetes mellitus (DM) is a metabolic disorder associated with declining of memory function. Glucagon like peptide-1 (GLP-1) has a role on memory function; binding of GLP-1 and GLP-1 receptor (GLP-1R) can enhance synaptic plasticity. Physical exercise has effect in increasing GLP-1 levels mediated by interleukin (IL)-6 in plasma. However, the effect of physical exercise on GLP-1 and GLP-1R in hippocampus is still unclear. Therefore, we investigated the effect of continuous and interval training on memory function through GLP-1/GLP-1R and its relation to hippocampal IL-6 of DM rats. This was an experimental study using 8-week-old Wistar rats, divided into four groups: normal control (Con); DM control (ConDM); DM with continuous training (DM-CT); and DM with interval training (DM-IT). DM-CT and DM-IT rats were trained six times a week for six weeks. All rats performed the forced alteration Y-maze test to verify spatial memory function. We analysed GLP-1 and IL-6 level by ELISA and GLP-1R by RT-PCR. We found decreased spatial memory function in DM rats accompanied by decreased hippocampal GLP-1 and GLP-1R. Physical exercise promote memory function in DM rats associated with restoration of hippocampal GLP-1 or GLP-1R level. The GLP-1 level is associated with hippocampal IL-6 level. Continuous training slightly increases GLP-1 level while interval training can maintain expression of hippocampal GLP-1R in DM rats. Our findings suggest that physical exercise may promote memory function by slightly increase the level of hippocampal GLP-1 and maintaining expression hippocampal GLP-1R.

Effect of Bariatric Surgery on Metabolic Diseases and Underlying Mechanisms

Obesity is a highly prevalent public health concern, attributed to multifactorial causes and limited in treatment options. Several comorbidities are closely associated with obesity such as the development of type 2 diabetes mellitus (T2DM), cardiovascular and cerebrovascular diseases, and nonalcoholic fatty liver disease (NAFLD). Bariatric surgery, which can be delivered in multiple forms, has been remarked as an effective treatment to decrease the prevalence of obesity and its associated comorbidities. The different types of bariatric surgery create a variety of new pathways for food to metabolize in the body and truncate the stomach's caliber. As a result, only a small quantity of food is tolerated, and the body mass index noticeably decreases. This review describes the improvements of obesity and its comorbidities following bariatric surgery and their mechanism of improvement. Additionally, endocrine function improvements after bariatric surgery, which contributes to the patients' health improvement, are described, including the role of glucagon-like peptide-1 (GLP-1), fibroblast growth factors 19 and 21 (FGF-19, FGF-21), and pancreatic peptide YY (PYY). Lastly, some of the complications of bariatric surgery, including osteoporosis, iron deficiency/anemia, and diarrhea, as well as their potential mechanisms, are described.

Physiopathology of Lifestyle Interventions in Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a major health problem, and its prevalence has increased in recent years. Diet and exercise interventions are the first-line treatment options, with weight loss via a hypocaloric diet being the most important therapeutic target in NAFLD. However, most NAFLD patients are not able to achieve such weight loss. Therefore, the requisite is the investigation of other effective therapeutic approaches. This review summarizes research on understanding complex pathophysiology underlying dietary approaches and exercise interventions with the potential to prevent and treat NAFLD.

Short-term interval exercise suppresses acylated ghrelin and hunger during caloric restriction in women with obesity

Caloric restriction is suggested to increase hunger, in part, through complex interactions of hormones and behavior that contribute to challenges in long-term weight loss. Although intense exercise may attenuate appetite, no data exist testing the effects of interval exercise (INT) during a low-calorie diet (LCD) on appetite regulation. We hypothesized that LCD+INT would favorably influence satiety when compared with an energy-deficit matched LCD in women with obesity. Twenty-six women with obesity (47.3±2.4 yrs; 37.3 ± 1.2 kg/m2) were randomized to either LCD (n = 13; mixed meals of ~1200 kcal/d) or LCD+INT (n = 13; 60 min/d of supervised interval exercise at 90% HRpeak for 3 min and 50% HRpeak for 3 min) for 2 weeks. An additional 350kcal (shake) was provided to LCD+INT individuals post-exercise to equate energy availability between groups. Total PYY, acylated ghrelin and des-ghrelin were measured at 0, 30 and 60 min of a 75g OGTT before and after the intervention. Visual analog scales were also administered at 0 and 120 min of the OGTT to assess appetite perception. Food logs were recorded prior to and during the intervention to ensure caloric intake compliance. Compared with pre-intervention conditions, both interventions decreased food intake (P = 0.001) and body fat (P < 0.01). There was no effect on fasting PYY, but both LCD and LCD+INT increased post-prandial PYY iAUC (P < 0.001) relative to pre-intervention. LCD+INT maintained fasting acylated ghrelin (P = 0.06) and suppressed post-prandial acylated ghrelin iAUC (P = 0.04) compared to LCD. Neither intervention impacted circulating des- ghrelin before or following the OGTT. Interestingly, LCD+INT attenuated fasting hunger and maintained fullness compared with LCD (P = 0.05 and P = 0.06, respectively). Taken together, interval exercise favors acylated ghrelin suppression and perception of hunger during a LCD in women with obesity.

Exercise Training Rapidly Increases Hepatic Insulin Extraction in NAFLD

PURPOSE

We aimed to determine the immediacy of exercise intervention on liver-specific metabolic processes in nonalcoholic fatty liver disease.

METHODS

We undertook a short-term (7-d) exercise training study (60 min·d treadmill walking at 80%-85% of maximal heart rate) in obese adults (N = 13, 58 ± 3 yr, 34.3 ± 1.1 kg·m, >5% hepatic lipid by H-magnetic resonance spectroscopy). Insulin sensitivity index was estimated by oral glucose tolerance test using the Soonthorpun model. Hepatic insulin extraction (HIE) was calculated as the molar difference in area under the curve (AUC) for insulin and C-peptide (HIE = 1 - (AUCInsulin/AUCC-Pep)).

RESULTS

The increases in HIE, V˙O2max, and insulin sensitivity index after the intervention were 9.8%, 9.8%, and 34%, respectively (all, P < 0.05). Basal fat oxidation increased (pre: 47 ± 6 mg·min vs post: 65 ± 6 mg·min, P < 0.05) and carbohydrate oxidation decreased (pre: 160 ± 20 mg·min vs post: 112 ± 15 mg·min, P < 0.05) with exercise training. After the intervention, HIE correlated positively with adiponectin (r = 0.56, P < 0.05) and negatively with TNF-α (r = -0.78, P < 0.001).

CONCLUSIONS

By increasing HIE along with peripheral insulin sensitivity, aerobic exercise training rapidly reverses some of the underlying physiological mechanisms associated with nonalcoholic fatty liver disease, in a weight loss-independent manner. This reversal could potentially act through adipokine-related pathways.

Non-invasive assessment of hepatic lipid subspecies matched with non-alcoholic fatty liver disease phenotype

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive hepatic fat accumulation. Increased hepatic saturated fats and decreased hepatic polyunsaturated fats may be particularly lipotoxic, contributing to metabolic dysfunction. We compared hepatic lipid subspecies in adults with and without NAFLD, and examined links with hallmark metabolic and clinical characteristics of NAFLD.

METHODS AND RESULTS

Nineteen adults with NAFLD (total hepatic fat:18.8 ± 0.1%) were compared to sixteen adults without NAFLD (total hepatic fat: 2.1 ± 0.01%). ¹H-MRS was used to assess hepatic lipid subspecies. Methyl, allylic, methylene, and diallylic proton peaks were measured. Saturation, unsaturation, and polyunsaturation indices were calculated. Whole-body phenotyping in a subset of participants included insulin sensitivity (40 mU/m² hyperinsulinemic-euglycemic clamps), CT-measured abdominal adipose tissue depots, exercise capacity, and serum lipid profiles. Participants with NAFLD exhibited more saturated and less unsaturated hepatic fat, accompanied by increased insulin resistance, total and visceral adiposity, triglycerides, and reduced exercise capacity compared to controls (all P < 0.05). All proton lipid peaks were related to insulin resistance and hypertriglyceridemia (P < 0.05).

CONCLUSION

Participants with NAFLD preferentially stored excess hepatic lipids as saturated fat, at the expense of unsaturated fat, compared to controls. This hepatic lipid profile was accompanied by an unhealthy metabolic phenotype.

Combined treatment of dipeptidyl peptidase-4 inhibitor and exercise training improves lipid profile in KK/Ta mice

NEW FINDINGS

What is the central question of this study? Exercise for type 2 diabetes patients treated with insulin therapy involves the risk of hypoglycaemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors can be effective in combination with exercise because they reduce the incidence of hypoglycaemia. We evaluated the effect of this combination of treatments on hepatic lipid metabolism in diabetic KK/Ta mice. What is the main finding and its importance? The combination of a DPP-4 inhibitor and exercise, which lowers the risk of hypoglycaemia, is useful for improving insulin resistance by inhibiting excess insulin secretion and decreasing hepatic lipid accumulation, validated by downregulated CD36.

ABSTRACT

The role of exercise training in prevention of diabetes and/or dyslipidaemia has been firmly established. Dipeptidyl peptidase-4 (DPP-4) inhibitors improve insulin sensitivity and have attracted attention as therapeutics for hepatic lipid accumulation. The effect of a combination of DPP-4 inhibitor and exercise training on the prevention and treatment of hepatic lipid accumulation is unclear. Here, we investigated whether alogliptin, a DPP-4 inhibitor, enhances the preventive effect of exercise-induced hepatic lipid accumulation in diabetic mice. Balb/c and KK/Ta mice were fed a high-fat diet. Mice were divided into the following five groups: B, Balb/c mice; K, KK/Ta mice; K-A, KK/Ta mice with alogliptin (0.01%); K-Ex, KK/Ta mice with exercise training (3 days week^-1 , 15-20 m min^-1 for 30 min); and K-Ex+A, KK/Ta mice with alogliptin and exercise training (n = 8 or 9 mice per group). After 8 weeks, glucose, insulin and triglyceride concentrations in the blood and triglyceride levels in the liver were significantly lower in the K-Ex+A group than in the K group. The liver expression level of PPAR-γ in the K group was significantly higher than that in the other groups. Additionally, the liver CD36 expression level was significantly lower in the K-Ex+A and B groups than in the K group. Thus, combined therapy of a DPP-4 inhibitor with exercise training was effective against high-fat diet-induced hepatic lipid accumulation in KK/Ta mice. The results of this study provide useful support for the practice of safe exercise therapy even in diabetic patients who require treatment with a DPP-4 inhibitor.

Two weeks of exercise training intensity on appetite regulation in obese adults with prediabetes

No short-term exercise data exist testing whether training intensity modifies hormonal and perceived appetite in obese adults with prediabetes. Therefore, we compared the effects of short-term moderate-continuous (CONT) vs. high-intensity interval (INT) training on appetite regulation. Twenty-eight obese adults [age: 61.3 ± 1.5 yr; body mass index (BMI): 33.2 ± 1.1 kg/m2] with prediabetes were randomized to work-matched CONT ( n = 14) or INT ( n = 14) training for 2 wk. Plasma acylated ghrelin (AG), des-acylated ghrelin (dAG), active glucagon-like peptide-1 (GLP-1), and insulin were measured at 0, 30, and 60 min of a 75-g oral glucose tolerance test (OGTT) before and after training. Visual analog scales were administered at 0 and 120 min during the OGTT to examine perceived appetite. Three-day food logs were collected before and after testing to assess ad libitum diet. CONT and INT increased peak oxygen consumption ( P < 0.01) and decreased BMI ( P < 0.01). Although neither intervention altered fasting levels of AG ( P = 0.94), dAG ( P = 0.36), or insulin ( P = 0.67), CONT raised GLP-1 compared with INT ( P = 0.05). Exercise training did not affect postprandial suppression of AG ( P = 0.81) and dAG ( P = 0.67) or stimulation of GLP-1 ( P = 0.67) and insulin ( P = 0.32). Both interventions tended to decrease total energy and protein intake ( P = 0.09 and P = 0.05, respectively), despite no change in fasting hunger ( P = 0.88) and reduced perceived fullness at 120 min during the OGTT ( P = 0.05). We conclude that 2 wk of exercise training intensity does not modulate appetite-regulatory hormones in obese adults with prediabetes. Although perceived fullness to the OGTT was reduced after exercise, CONT and INT decreased energy intake, suggesting that exercise does not elicit compensatory appetite behavior to gain weight. NEW & NOTEWORTHY Adults with prediabetes are at risk for appetite dysregulation. Although exercise promotes weight management, it is unclear whether moderate-continuous or high-intensity interval training is more beneficial for appetite regulation. We show that 2 wk of exercise, independent of intensity, does not alter postprandial appetite hormones or hunger, despite slight reductions in food intake and weight. These data support exercise as an effective method to induce negative energy balance without compensatory weight gain.

Impact of short-term exercise training intensity on β-cell function in older obese adults with prediabetes

The effect of work-matched exercise intensity on β-cell function is unknown in people with prediabetes before clinical weight loss. We determined if short-term moderate continuous (CONT) vs. high-intensity interval (INT) exercise increased β-cell function. Thirty-one subjects (age: 61.4 ± 2.5 yr; body mass index: 32.1 ± 1.0 kg/m2) with prediabetes [American Diabetes Association criteria, 75-g oral glucose tolerance test (OGTT)] were randomized to work-matched CONT (70% HRpeak) or INT (3 min 90% HRpeak and 3 min 50% HRpeak) exercise for 60 min/day over 2 wk. A 75-g 2-h OGTT was conducted after an overnight fast, and plasma glucose, insulin, C-peptide, and free fatty acids were determined for calculations of skeletal muscle [oral minimal model (OMM)], hepatic (homeostatic model of insulin resistance), and adipose (Adipose-IR) insulin sensitivity. β-Cell function was defined from glucose-stimulated insulin secretion (GSIS, deconvolution modeling) and the disposition index (DI). Glucagon-like polypeptide-1 [GLP-1(active)] and glucose-dependent insulinotropic polypeptide (GIP) were also measured during the OGTT, along with peak oxygen consumption and body composition. CONT and INT increased skeletal muscle- but not hepatic- or adipose-derived DI ( P < 0.05). Although both treatments tended to reduce fasting GLP-1(active) ( P = 0.08), early phase GLP-1(active) increased post-CONT and INT training ( P < 0.001). Interestingly, CONT exercise increased fasting GIP compared with decreases in INT ( P = 0.02). Early and total-phase skeletal muscle DI correlated with decreased total glucose area under the curve ( r = -0.52, P = 0.002 and r = -0.50, P = 0.003, respectively). Independent of intensity, short-term training increased pancreatic function adjusted to skeletal muscle in relation to improved glucose tolerance in adults with prediabetes. Exercise also uniquely affected GIP and GLP-1(active). Further work is needed to elucidate the dose-dependent mechanism(s) by which exercise impacts glycemia. NEW & NOTEWORTHY Exercise is cornerstone for reducing blood glucose, but whether high-intensity interval training is better than moderate continuous exercise is unclear in people with prediabetes before weight loss. We show that 2 wk of exercise training, independent of intensity, increased pancreatic function in relation to elevated glucagon-like polypeptide-1 secretion. Furthermore, β-cell function, but not insulin sensitivity, was also correlated with improved glucose tolerance. These data suggest that β-cell function is a strong predictor of glycemia regardless of exercise intensity.

Exercise and glucagon-like peptide-1: Does exercise potentiate the effect of treatment?

Recently, glucagon-like peptide-1 (GLP-1) receptor agonists have become a cornerstone for the treatment of obese patients with type 2 diabetes (T2D), exhibiting favorable effects on the cardiovascular outcome. In T2D, impaired GLP-1 secretion/function is observed, and gut microbiota dysbiosis is related to the GLP-1 resistance. Prior research has revealed that exercise increases GLP-1 levels in healthy and obese individuals; however, the efficacy of exercise on GLP-1 levels in patients with T2D remains unclear. Exercise may improve GLP-1 resistance rather than GLP-1 secretion in patients with T2D. Exercise increases the gut microbiota diversity, which could contribute to improving the GLP-1 resistance of T2D. Furthermore, the gut microbiota may play a role in the correlation between exercise and GLP-1. The combination of exercise and GLP-1-based therapy may have a synergistic effect on the treatment of T2D. Although the underlying mechanism remains unknown, exercise potentiates the efficacy of GLP-1 receptor agonist treatment in patients with T2D.

Combining Short-Term Interval Training with Caloric Restriction Improves ß-Cell Function in Obese Adults

Although low-calorie diets (LCD) improve glucose regulation, it is unclear if interval exercise (INT) is additive. We examined the impact of an LCD versus LCD + INT training on ß-cell function in relation to glucose tolerance in obese adults. Twenty-six adults (Age: 46 ± 12 year; BMI 38 ± 6 kg/m²) were randomized to 2-week of LCD (~1200 kcal/day) or energy-matched LCD + INT (60 min/day alternating 3 min at 90 and 50% HRpeak). A 2 h 75 g oral glucose tolerance test (OGTT) was performed. Insulin secretion rates (ISR) were determined by deconvolution modeling to assess glucose-stimulated insulin secretion ([GSIS: ISR/glucose total area under the curve (tAUC)]) and ß-cell function (Disposition Index [DI: GSIS/IR]) relative to skeletal muscle (Matsuda Index), hepatic (HOMA-IR) and adipose (Adipose-IR_fasting) insulin resistance (IR). LCD + INT, but not LCD alone, reduced glucose and total-phase ISR tAUC (Interactions: p = 0.04 and p = 0.05, respectively). Both interventions improved skeletal muscle IR by 16% (p = 0.04) and skeletal muscle and hepatic DI (Time: p < 0.05). Improved skeletal muscle DI was associated with lower glucose tAUC (r = -0.57, p < 0.01). Thus, LCD + INT improved glucose tolerance more than LCD in obese adults, and these findings relate to ß-cell function. These data support LCD + INT for preserving pancreatic function for type 2 diabetes prevention.