Graded Resistance Exercise And Type 2 Diabetes in Older adults (The GREAT2DO study): methods and baseline cohort characteristics of a randomized controlled trial

Phosphorylation of AMPKα at Ser485/491 Is Dependent on Muscle Contraction and Not Muscle-Specific IGF-I Overexpression

Glucose is an important fuel for highly active skeletal muscles. Increased adenosine monophosphate (AMP)/adenosine triphosphate (ATP) ratios during repetitive contractions trigger AMP-activated protein kinase (AMPK), indicated by phosphorylation of AMPKαThr172, which promotes glucose uptake to support heightened energy needs, but it also suppresses anabolic processes. Inhibition of AMPK can occur by protein kinase B (AKT)-mediated phosphorylation of AMPKαSer485/491, releasing its brake on growth. The influence of insulin-like growth factor I (IGF-I) on glucose uptake and its interplay with AMPK activation is not well understood. Thus, the goal of this study was to determine if increased muscle IGF-I altered AMPKα phosphorylation and activity during muscle contraction. Adult male mice harboring the rat Igf1a cDNA regulated by the fast myosin light chain promoter (mIgf1+/+) and wildtype littermates (WT) were used in the study. mIgf1+/+ mice had enhanced glucose tolerance and insulin-stimulated glucose uptake, but similar exercise capacity. Fatiguing stimulations of extensor digitorum longus (EDL) muscles resulted in upregulated AMPKα phosphorylation at both Thr172 and Ser485/491 in WT and mIgf1+/+ muscles. No differences in the phosphorylation response of the downstream AMPK target TBC1D1 were observed, but phosphorylation of raptor was significantly higher only in WT muscles. Further, total raptor content was elevated in mIgf1+/+ muscles. The results show that high muscle IGF-I can enhance glucose uptake under resting conditions; however, in contracting muscle, it is not sufficient to inhibit AMPK activity.

Effect of resistance vs. aerobic exercise in pre-diabetes: an RCT

BACKGROUND

This study aimed to assess the different impacts of aerobic and resistance exercise intervention on pre-diabetes and its possible influencing factor (obesity) to identify which exercise intervention mode was better for pre-diabetes to control their blood glucose levels.

METHODS

Single-blind randomized controlled trial. Participants were recruited from Southwest Hospital between February 2016 and May 2017 and randomly divided into three groups using stratified randomization: aerobic exercise (A), resistance exercise (R), and control (C). The effects of each group were analyzed, and the relationship with obesity was investigated following a 12-week intervention.

RESULTS

Eighty participants were enrolled (9 were lost, and 1 was excluded). Finally, 26 participants were included in group A, 23 in group R, and 21 in group C. In groups A and R, FPG, OGTT 2-h PG, and HOMA2-IR decreased by 6.17% (P = 0.001) and 4.81% (P = 0.019), 20.39% (P < 0.001) and 16.50% (P < 0.001), and 8.34% (P = 0.026) and 18.31% (P = 0.001, superior to that in group A), respectively (all P < 0.001 compared with group C, with no significant differences between groups A and R). The ratio of reversal to euglycemia was 69.2% (P = 0.003 compared with group C) in group A and 43.5% (P = 0.213 compared with group C) in group R. The decreased ratio of GSP in group R was greater (65.2%, P = 0.008 compared with group C) compared with group A (38.5%, P = 0.355 compared with group C). Decreases in the parameters BMI (3.1 ± 3.2% P < 0.001, moderately positive correlation with the decreased FPG level, r = 0.498, P = 0.010, two-tailed) and waist circumference (3.1 ± 2.7% P < 0.001) were noted in group A, but no significant correlations were noted between other indicators in group R.

CONCLUSIONS

Both resistance and aerobic exercise can control and reverse IGR. Compared with aerobic exercise, resistance exercise may be superior in terms of GSP and IR improvement. Aerobic exercise decreases blood glucose levels through weight loss. However, the effect of resistance exercise might not be mediated via weight loss and obesity control.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2000038304. Registered on September 17, 2020.

Effects of Polygonatum sibiricum saponin on hyperglycemia, gut microbiota composition and metabolic profiles in type 2 diabetes mice

Diabetes is a global disease that endangers human health. As reported, saponins are effective bioactive compounds for treating type 2 diabetes mellitus (T2DM) and have nontoxic side effects. This study aimed to examine the hypoglycemic effects of Polygonatum sibiricum saponin (PSS) on T2DM mice. We found that PSS could significantly decrease the levels of insulin secretion and fasting blood glucose (FBG) in T2DM mice. And the level of triacylglycerol (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the blood was decreased. In contrast, the content of high-density lipoprotein cholesterol (HDL-C) was increased. 16S rDNA sequencing was used to evaluate the changes in the gut microbiota of T2DM mice, and metabolites were analyzed by metabolomic profiling. The results showed that PSS could decrease the abundance of Firmicutes in T2DM mice, increase the abundance of Bacteroidetes. It also increased the abundance of some bacterial genera (Lactobacillus, Lachnospiraceae_NK4A136_group and Intestinimonas). The phenotypes of the gut microbiome also changed accordingly. Metabolomics analysis showed that carbohydrate metabolism and amino acid metabolisms, such as L-alanine and L-glutamic acid, were greatly affected by PSS. In addition, the levels of inositol and chlorogenic acid in metabolites also increased significantly under PSS intervention. In general, PSS could exert its hypoglycemic effect, regulate the gut microbiota and affect the metabolism of T2DM mice.

The Effect of High-Intensity Power Training on Habitual, Intervention and Total Physical Activity Levels in Older Adults with Type 2 Diabetes: Secondary Outcomes of the GREAT2DO Randomized Controlled Trial

BACKGROUND

We examined the effect of power training on habitual, intervention and total physical activity (PA) levels in older adults with type 2 diabetes and their relationship to metabolic control.

MATERIALS AND METHODS

103 adults with type 2 diabetes were randomized to receive supervised power training or sham exercise three times/week for 12 months. Habitual, intervention, and total PA, as well as insulin resistance (HOMA2-IR) and glycosylated hemoglobin (HbA1c), were measured.

RESULTS

Participants were aged 67.9 ± 5.5 yrs, with well-controlled diabetes (HbA1c = 7.1%) and higher than average habitual PA levels compared to healthy peers. Habitual PA did not change significantly over 12 months (p = 0.74), and there was no effect of group assignment on change over time in habitual PA over 0-6 (p = 0.16) or 0-6-12 months (p = 0.51). By contrast, intervention PA, leg press tonnage and total PA increased over both 6- and 12-month timepoints (p = 0.0001), and these changes were significantly greater in the power training compared to the sham exercise group across timepoints (p = 0.0001). However, there were no associations between changes in any PA measures over time and changes in metabolic profile.

CONCLUSION

Structured high-intensity power training may be an effective strategy to enhance overall PA in this high-risk cohort.

Potential Utility of Self-Report Measures of Affect to Optimise Exercise Adherence in People with Type 2 Diabetes

Exercise is essential for managing type 2 diabetes, however approximately only 40% of people with the condition meet guidelines. The aim of this review is to examine the evidence regarding the use self-report measures of affect to understand and predict exercise adherence. Self-reported affect has been successfully used to regulate exercise intensity, monitor training load, prevent injury, and predict future physical activity participation in otherwise healthy and some clinical populations. Specific recommendations are provided for research to explore the utility of self-report measures of affect to promote exercise adherence in people with type 2 diabetes.

Prevention of Diabetic Kidney Disease in the Light of Current Literature

Diabetes is a rapidly growing problem of the community health. The resulting morbidity and mortality are responsible for the complications of diabetes. Nephropathy caused by diabetes often causes serious morbidity and mortality. In this review, we discuss the current approaches to prevent diabetic nephropathy based on the available literature evidence.

Systematic review and meta-analysis of the efficacy of different exercise programs in pilocarpine induced status epilepticus models

PURPOSE

To conduct a systematic review and meta-analysis of studies testing exercise in animal models of pilocarpine induced status epilepticus (SE) and to compare the efficacy of different training strategies used in those studies.

METHODS

We searched 2 online databases (Pubmed and Web of Science) for studies analyzing the efficacy of different trainings in pilocarpine-induced SE models. Training was categorized into forced physical training (PT), voluntary PT and resistance PT. Two reviewers independently extracted data on study quality, behavioral seizures, and histological, chemical and cognitive outcomes. Data were pooled by means of a meta-analysis.

RESULTS

Among 17 selected studies; 174 animals from 8 studies with 10 comparison groups showed that exercise intervention after induction of SE significantly decreased spontaneous recurrent seizures with [mean difference (MD)=-1.80, 95% confidence interval (CI): -3.22, -0.37, p=0.02] and 60 animals showed statistically significant decrease in latency in Morris water maze (standardized mean difference (SMD)=-2.57, 95% CI: -4.06, -1.08, p=0.0007). Although not statistically significant, still a remarkable increase in number of CA1 neurons and hippocampal BDNF level (MD=2.27, [95% CI: -1.20, 5.73], p=0.19, SMD=1.07, [95% CI: -0.36, 2.51], p=0.14 respectively) and a decrease in mossy fibers sprouting (SMD=-1.03, [95% CI: -3.06, 1.00], p=0.32) were observed. PT interventions in 72 animals before induction of SE showed favorable increase in latency to develop SE (MD=8.34, [95% CI: -3.10, 19.78], p=0.15) but no remarkable improvements in latency for the first motor sign and motor signs intensity.

CONCLUSIONS

PT after SE reduces the recurrent seizures and improves the morphological, biochemical and cognitive profiles of pilocarpine epileptic models. Resistance PT was identified as particularly effective in reducing behavioral seizures. The efficacy of training was also dependent upon duration.

Resistance Training for Glycemic Control, Muscular Strength, and Lean Body Mass in Old Type 2 Diabetic Patients: A Meta-Analysis

INTRODUCTION

Type 2 diabetes (T2D) in elderly patients is associated with accelerated loss of skeletal muscle mass and strength. However, there are few meta-analysis reviews which investigate the effects of resistance training (RT) on glycemic control and skeletal muscle in the patients.

METHODS

Three electronic databases were searched (from the earliest date available to November 2016). Studies were included according to the inclusion criteria: T2D patients at least 60 years old, fasting plasma glucose of at least 7.0, and at least 8 weeks of RT.

RESULTS

Fifteen cohorts of eight studies (360 patients, average age 66 years) met the inclusion criteria. RT groups lowered glycosylated hemoglobin (HbA1c) (mean ES = -0.37, 95% CI = -0.55 to -0.20, P < 0.01) but did not result in a significant effect on lean body mass (LBM) (mean ES = 0.08, 95% CI = -0.15 to 0.30, P = 0.50). Homogeneity was shown between studies regarding HbA1c and LBM (Q = 15.70, df = 9, P = 0.07 and Q = 0.12, df = 4, P = 0.998, respectively). High-intensity subgroups showed a slight tendency to improve (rather than duration, frequency, and weekly volume) and to decrease HbA1c levels more than low-intensity subgroups (P = 0.37). RT increased muscular strength (mean ES = 1.05, 95% CI = 0.26-1.84, P = 0.01). No training components explained the heterogeneity between studies with changes in muscle strength.

CONCLUSION

RT improves glycemic control and muscle strength in elderly patients with T2D. RT with high intensity can be a strategy to treat patients with T2D and sarcopenia associated with aging.

Management of Atherosclerotic Cardiovascular Disease Risk Factors in the Older Adult Patient With Diabetes

: Older adults with diabetes are at higher risk for atherosclerotic cardiovascular disease (ASCVD) than younger adults with diabetes and older adults without diabetes. The rationale to implement ASCVD risk-lowering therapies in older adults with diabetes is compelling. Recommendations for lifestyle modification, lipid-lowering therapy, blood pressure management, blood glucose control, and aspirin therapy are often based on studies that show their efficacy in younger populations. However, the risks associated with each of these interventions increase with age, and favorable risk-to-benefit ratios demonstrated in younger adults with diabetes are less certain in older populations. The variability in health status among older adults is pertinent. Those with robust health are more likely to tolerate and derive benefit from many therapies when compared with those who have more complex health including frailty. Age- and/or frailty-stratified data to help clarify these relationships are sparse. In this Perspective, current recommendations for modifying ASCVD risk are described with a review of the pertinent literature that guides their application in older adults. A pragmatic approach to the treatment of ASCVD risk factors in older adults with diabetes is presented.