Independent and combined effect of diet and exercise in adults with prediabetes

Metabolic disorders in prediabetes: From mechanisms to therapeutic management

Diabetes, one of the world's top ten diseases, is known for its high mortality and complication rates and low cure rate. Prediabetes precedes the onset of diabetes, during which effective treatment can reduce diabetes risk. Prediabetes risk factors include high-calorie and high-fat diets, sedentary lifestyles, and stress. Consequences may include considerable damage to vital organs, including the retina, liver, and kidneys. Interventions for treating prediabetes include a healthy lifestyle diet and pharmacological treatments. However, while these options are effective in the short term, they may fail due to the difficulty of long-term implementation. Medications may also be used to treat prediabetes. This review examines prediabetic treatments, particularly metformin, glucagon-like peptide-1 receptor agonists, sodium glucose cotransporter 2 inhibitors, vitamin D, and herbal medicines. Given the remarkable impact of prediabetes on the progression of diabetes mellitus, it is crucial to intervene promptly and effectively to regulate prediabetes. However, the current body of research on prediabetes is limited, and there is considerable confusion surrounding clinically relevant medications. This paper aims to provide a comprehensive summary of the pathogenesis of pre-diabetes mellitus and its associated therapeutic drugs. The ultimate goal is to facilitate the clinical utilization of medications and achieve efficient and timely control of diabetes mellitus.

Health behavior of Austrian tertiary students focusing on diet type linked to sports and exercise-first glimpse of results from the "sustainably healthy-from science 2 high school and university" study

Background

There is a strong association between lifestyle behavior and health status. While young adulthood is a critical period for adopting and stabilizing lifelong healthy behavior, university life is independently associated with psychological stressors that may further affect health and well-being.

Objective

The present multidisciplinary study aimed to examine the health behavior of Austrian college and university students, differentiated based on diet types (vegan, vegetarian, and omnivorous) and physical activity (PA) habits.

Methods

Following a cross-sectional study design, a total number of 6,148 students (65.3% females; 66.1% bachelor students, 67.0% from urban areas; mean age: 24.8 years) from 52 Austrian college/universities participated in an online survey and provided data on sociodemographic characteristics, dietary patterns, PA habits, and other lifestyle behavior characteristics, including alcohol intake and smoking.

Results

Across the total sample, 74.0% had a normal weight (BMI = 18.5-25.0 kg/m2), while the prevalence of overweight/obesity (BMI ≥ 30.0 kg/m2) was lower in females than males and more in rural than urban students (p < 0.01). The general prevalence of vegetarian and vegan diets was 22.8 and 6.0%, respectively, with a predominance of females, graduates, and urban students compared to their peers (p < 0.01). The majority of students (79.3%) had a regular engagement in sport/exercise, with a predominance of vegetarian or vegan students compared to omnivores (p < 0.01). Vegans and vegetarians had a lower alcohol intake (p < 0.01) but no differences in smoking habits (p > 0.05) compared to omnivores. Students engaging in sport/exercise had a lower smoking rate and higher intake of fruits, vegetables, and fluids compared to inactive students (p < 0.01).

Conclusion

The present findings suggest that diet type and PA habits of college/university students have an impact on other health behaviors, highlighting the interconnected nature of lifestyle habits and health behavior.

Study Protocol of "Sustainably Healthy-From Science 2 Highschool & University"-Prevalence of Mixed, Vegetarian, and Vegan Diets Linked to Sports & Exercise among Austrian Tertiary Students and Lecturers/Academic Staff

Healthy lifestyle is the major indicator of individual and public health especially in target populations (e.g., during emerging adulthood). Evidence indicates that unhealthy lifestyle behaviors are strongly associated with the increasing prevalence of chronic diseases. The dual approach of sustainable health (i.e., physical exercise tied to a healthy diet) is an effective lifestyle strategy to control and manage health-related disorders, including overweight/obesity. Based on the evidence on plant-based diets regarding health and considering the growing prevalence of vegans and vegetarians worldwide, limited data exist on the health-related behaviors of those who follow plant-based vs. mixed diets in young adulthood. This multidisciplinary study is the first to examine the association between diet type (mixed, vegetarian, and vegan diets) and various health-related behaviors (primarily physical activity, sport, & exercise) among college/university students and lecturers/academic staff in Austria nationwide. Following a cross-sectional study design and using online questionnaires, 4510 tertiary students and 1043 lecturers/academic staff provided data on sociodemographic characteristics, dietary patterns, physical exercise habits, and other lifestyle behaviors (sleep, alcohol intake, smoking, etc.) along with information on health status and quality of life. While the data will be analyzed based on differentiated sociodemographic and health-related categories, the influence of the COVID-19 pandemic on lifestyle behaviors will also be evaluated. As a study protocol, this article represents comprehensive details of the design, purposes, and associated analytical measures of the present study within the tertiary educational context.

Appraisal of Triglyceride-Related Markers as Early Predictors of Metabolic Outcomes in the PREVIEW Lifestyle Intervention: A Controlled Post-hoc Trial

Background: Individuals with pre-diabetes are commonly overweight and benefit from dietary and physical activity strategies aimed at decreasing body weight and hyperglycemia. Early insulin resistance can be estimated via the triglyceride glucose index {TyG = Ln [TG (mg/dl) × fasting plasma glucose (FPG) (mg/dl)/2]} and the hypertriglyceridemic-high waist phenotype (TyG-waist), based on TyG x waist circumference (WC) measurements. Both indices may be useful for implementing personalized metabolic management. In this secondary analysis of a randomized controlled trial (RCT), we aimed to determine whether the differences in baseline TyG values and TyG-waist phenotype predicted individual responses to type-2 diabetes (T2D) prevention programs. Methods: The present post-hoc analyses were conducted within the Prevention of Diabetes through Lifestyle intervention and population studies in Europe and around the world (PREVIEW) study completers (n = 899), a multi-center RCT conducted in eight countries (NCT01777893). The study aimed to reduce the incidence of T2D in a population with pre-diabetes during a 3-year randomized intervention with two sequential phases. The first phase was a 2-month weight loss intervention to achieve ≥8% weight loss. The second phase was a 34-month weight loss maintenance intervention with two diets providing different amounts of protein and different glycemic indices, and two physical activity programs with different exercise intensities in a 2 x 2 factorial design. On investigation days, we assessed anthropometrics, glucose/lipid metabolism markers, and diet and exercise questionnaires under standardized procedures. Results: Diabetes-related markers improved during all four lifestyle interventions. Higher baseline TyG index (p < 0.001) was associated with greater reductions in body weight, fasting glucose, and triglyceride (TG), while a high TyG-waist phenotype predicted better TG responses, particularly in those randomized to physical activity (PA) of moderate intensity. Conclusions: Two novel indices of insulin resistance (TyG and TyG-waist) may allow for a more personalized approach to avoiding progression to T2D. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT01777893 reference, identifier: NCT01777893.

Repurposing anti-inflammasome NRTIs for improving insulin sensitivity and reducing type 2 diabetes development

Innate immune signaling through the NLRP3 inflammasome is activated by multiple diabetes-related stressors, but whether targeting the inflammasome is beneficial for diabetes is still unclear. Nucleoside reverse-transcriptase inhibitors (NRTI), drugs approved to treat HIV-1 and hepatitis B infections, also block inflammasome activation. Here, we show, by analyzing five health insurance databases, that the adjusted risk of incident diabetes is 33% lower in patients with NRTI exposure among 128,861 patients with HIV-1 or hepatitis B (adjusted hazard ratio for NRTI exposure, 0.673; 95% confidence interval, 0.638 to 0.710; P < 0.0001; 95% prediction interval, 0.618 to 0.734). Meanwhile, an NRTI, lamivudine, improves insulin sensitivity and reduces inflammasome activation in diabetic and insulin resistance-induced human cells, as well as in mice fed with high-fat chow; mechanistically, inflammasome-activating short interspersed nuclear element (SINE) transcripts are elevated, whereas SINE-catabolizing DICER1 is reduced, in diabetic cells and mice. These data suggest the possibility of repurposing an approved class of drugs for prevention of diabetes.

Effects of Different Dosages of Interval Training on Glycemic Control in People With Prediabetes: A Randomized Controlled Trial

High-intensity interval training (HIIT) has been used as an alternative to moderate-intensity exercise training. Research has shown that HIIT produces better effects on glycemic control and hence the cardiometabolic risk in prediabetes. This randomized controlled trial was conducted to compare the effect of low-volume HIIT (LV-HIIT) with high-volume HIIT (HV-HIIT) on A1C and fasting blood glucose (FBG) in overweight adults with prediabetes. The trial included 60 young adults with prediabetes (32 male, 28 female). Subjects were randomly assigned to one of three equal-sized groups (n = 20): an LV-HIIT group (10 × 1-minute intervals at an interval intensity of ∼90% HR_max on a treadmill separated by 1 minute of easy recovery, with total exercise of 25 minutes/session), an HV-HIIT group (4 × 4-minute intervals at 90% of HR_max with 3 minutes of active recovery at 70% of HR_max between intervals, with total exercise of 40 minutes/session), and a control group (no exercise intervention). Exercise programs consisted of 3 sessions/week for 12 successive weeks. All participants followed a low-calorie diet for the 12-week intervention period. A1C and FBG were measured before and at the end of the 12-week trial. There were statistically significant effects on A1C and FBG from both exercise interventions (P <0.05). LV-HIIT and HV-HIIT significantly reduced A1C and FBG; however, HV-HIIT yielded a greater reduction in A1C than LV-HIIT (26.07 vs. 14.50%) and in FBG (17.80 vs. 13.22%) after exercise training, respectively. HIIT was found to be effective for glycemic control in prediabetes, with HV-HIIT being more effective than LV-HIIT in reducing A1C, FBG, and progression to type 2 diabetes in young adults with prediabetes.

Effect of aerobic exercise on insulin resistance and central adiposity disappeared after the discontinuation of intervention in overweight women

PURPOSE

This study aimed to assess whether the benefits of exercise on central adiposity and insulin resistance (HOMA-IR) are maintained after discontinuation of intervention in the overweight/obese (OWOB) women.

METHODS

The study subjects were from 2 independent studies with similar aerobic exercise (AE) intervention programs. In study I, 15 OWOB postmenopausal women with pre-diabetes (body mass index, BMI = 24-33 kg/m², aged 52-65 years) completed an 8-month exercise intervention and were followed for 2 years after the intervention. In study II, 12 OWOB (BMI = 25-35 kg/m², aged 30-50 years) premenopausal women participated in a 6-week AE and were followed for 4 years after the intervention. The exercise program consisted of progressive AE with intensity of 60%-75% of initial fitness level, 30-60 min/time and 3-5 times/week. Fat mass (FM) was assessed by Dual Energy X-ray Absorptiometry (DXA Prodigy; study I) or bioelectrical impedance device (Inbody 720; study II). Plasma glucose and insulin were assessed by chemiluminescent immunoassay and HOMA-IR was calculated.

RESULTS

Both 8-month and 6-week moderate AE were effective in reducing HOMA-IR (-18.9%, p = 0.012 and -26.7%, p = 0.046, respectively), and 8-month AE reduced FM at upper abdominal region (-6.2%, p = 0.021). However, these improvements were not maintained in either study at the follow-up.

CONCLUSION

The AE program used in these studies was effective to reduce insulin resistance and/or FM in central body region among overweight and obese women. However, when exercise intervention was discontinued, the beneficial effects following both short- and long-term intervention disappeared. Thus maintaining exercise seems to be required if one wants to reap the benefits of exercise in the long-term.

Hepatic insulin resistance both in prediabetic and diabetic patients determines postprandial lipoprotein metabolism: from the CORDIOPREV study

Background/aims

Previous evidences have shown the presence of a prolonged and exaggerated postprandial response in type 2 diabetes mellitus (T2DM) and its relation with an increase of cardiovascular risk. However, the response in prediabetes population has not been established. The objective was to analyze the degree of postprandial lipemia response in the CORDIOPREV clinical trial (NCT00924937) according to the diabetic status.

Methods

1002 patients were submitted to an oral fat load test meal (OFTT) with 0.7 g fat/kg body weight [12 % saturated fatty acids (SFA), 10 % polyunsaturated fatty acids (PUFA), 43 % monounsaturated fatty acids (MUFA), 10 % protein and 25 % carbohydrates]. Serial blood test analyzing lipid fractions were drawn at 0, 1, 2, 3 and 4 h during postprandial state. Postprandial triglycerides (TG) concentration at any point >2.5 mmol/L (220 mg/dL) has been established as undesirable response. We explored the dynamic response in 57 non-diabetic, 364 prediabetic and 581 type 2 diabetic patients. Additionally, the postprandial response was evaluated according to basal insulin resistance subgroups in patients non-diabetic and diabetic without pharmacological treatment (N = 642).

Results

Prevalence of undesirable postprandial TG was 35 % in non-diabetic, 48 % in prediabetic and 59 % in diabetic subgroup, respectively (p < 0.001). Interestingly, prediabetic patients displayed higher plasma TG and large triacylglycerol-rich lipoproteins (TRLs-TG) postprandial response compared with those non-diabetic patients (p < 0.001 and p = 0.003 respectively). Moreover, the area under the curve (AUC) of TG and AUC of TRLs-TG was greater in the prediabetic group compared with non-diabetic patients (p < 0.001 and p < 0.005 respectively). Patients with liver insulin resistance (liver-IR) showed higher postprandial response of TG compared with those patients with muscle-IR or without any insulin-resistance respectively (p < 0.001).

Conclusions

Our findings demonstrate that prediabetic patients show a lower phenotypic flexibility after external aggression, such as OFTT compared with nondiabetic patients. The postprandial response increases progressively according to non-diabetic, prediabetic and type 2 diabetic state and it is higher in patients with liver insulin-resistance. To identify this subgroup of patients is important to treat more intensively in order to avoid future cardiometabolic complications.

Targeting skeletal muscle mitochondria to prevent type 2 diabetes in youth

The prevalence of type 2 diabetes (T2D) has increased dramatically over the past two decades, not only among adults but also among adolescents. T2D is a systemic disorder affecting every organ system and is especially damaging to the cardiovascular system, predisposing individuals to severe cardiac and vascular complications. The precise mechanisms that cause T2D are an area of active research. Most current theories suggest that the process begins with peripheral insulin resistance that precedes failure of the pancreatic β-cells to secrete sufficient insulin to maintain normoglycemia. A growing body of literature has highlighted multiple aspects of mitochondrial function, including oxidative phosphorylation, lipid homeostasis, and mitochondrial quality control in the regulation of peripheral insulin sensitivity. Whether the cellular mechanisms of insulin resistance in adults are comparable to that in adolescents remains unclear. This review will summarize both clinical and basic studies that shed light on how alterations in skeletal muscle mitochondrial function contribute to whole body insulin resistance and will discuss the evidence supporting high-intensity exercise training as a therapy to circumvent skeletal muscle mitochondrial dysfunction to restore insulin sensitivity in both adults and adolescents.