Swimming intervention alleviates insulin resistance and chronic inflammation in metabolic syndrome

Associations of Relative Handgrip Strength and Aerobic and Strength Exercises with Metabolic Syndrome Prevalence

BACKGROUND

The purpose of this study was to investigate associations of relative handgrip strength and participation in aerobic and strength exercises with metabolic syndrome prevalence. Moreover, level of handgrip strength, exercise frequency, and types of participation in aerobic and strength exercises associated with reductions in metabolic syndrome prevalence were explored.

METHODS

This study relied on data from the Korean National Health and Nutrition Examination Survey, 2018, specifically data on handgrip strength level, aerobic and strength exercise levels, and metabolic syndrome prevalence. Aerobic exercise level was categorized as either moderate physical activity (>150 min/week) or vigorous physical activity (>75 min/week) or not engaging in those levels of exercise. Frequency of strength exercise was also recorded. Multivariate logistic regression analyses were used for data analysis.

RESULTS

A total 4836 adults were included in this study. Greater relative handgrip strength in both female and male adults was significantly associated with reduced metabolic syndrome prevalence. Levels of aerobic and strength exercise participation were higher in adults with greater relative handgrip strength. Aerobic and strength exercise participation was significantly associated with decreased metabolic syndrome prevalence in males, but the association was not significant in females.

CONCLUSIONS

The relative handgrip strength may instead be a marker of lower metabolic syndrome risk, and an increased participation in aerobic and strength exercise helps to reduce the risk of metabolic syndrome. Suggested exercises for female adults include light aerobic exercise such as walking and strength exercise including weight-bearing exercise and stair climbing.

N6-methyladenosine Demethylase FTO Induces the Dysfunctions of Ovarian Granulosa Cells by Upregulating Flotillin 2

Polycystic ovarian syndrome (PCOS) is often accompanied by overweight/obesity and insulin resistance. The dysfunctions of ovarian granulosa cells (GCs) are closely linked with the pathogenesis of PCOS. Fat mass and obesity-associated gene (FTO), an N6-methyladenosine (m6A) demethylase, has been reported to be implicated in the risks and insulin resistance of PCOS. However, the roles of FTO in the development of GCs along with its m6A-related regulatory mechanisms are poorly defined. Cell proliferative ability was detected by MTT assay. Cell apoptotic rate was measured via flow cytometry. Insulin resistance was assessed by GLUT4 transport potential. The mRNA and protein levels of FTO and flotillin 2 (FLOT2) were determined by RT-qPCR and western blot assays, respectively. FLOT2 was screened out to be a potential FTO target through differential expression analysis for the GSE95728 dataset and target prediction analysis by POSTAR2 and STARBASE databases. The interaction between FTO and FLOT2 was analyzed by RNA immunoprecipitation (RIP) assay. The effect of FTO upregulation on FLOT2 m6A level was measured by methylated RIP (meRIP) assay. FLOT2 mRNA stability was examined by actinomycin D assay. FTO overexpression facilitated cell proliferation, hindered cell apoptosis, and induced insulin resistance in GCs. FTO promoted FLOT2 expression by reducing m6A level on FLOT2 mRNA and increasing FLOT2 mRNA stability. FLOT2 loss weakened the effects of FTO overexpression on cell proliferation/apoptosis and insulin resistance in GCs. FTO induced the dysfunctions of GCs by upregulating FLOT2, suggesting that FTO/FLOT2 might play a role in the pathophysiology of PCOS.

The effect of water-based rhythmic exercise training on glucose homeostasis and thyroid hormones in postmenopausal women with metabolic syndrome

OBJECTIVES

The present study aimed to explore the effect of water-based rhythmic exercise training on fasting blood sugar (FBS), homeostatic model assessment (HOMA), insulin, thyroid stimulating hormone (TSH), and T4 in postmenopausal women with metabolic syndrome.

METHODS

In this clinical trial, 31 postmenopausal woman with metabolic syndrome aged 69.16 ± 2.02 years were randomly assigned to an experimental (n=16) and a control group (n=15). The training program was composed of 12 weeks of water-based rhythmic exercise training performed intermittently for 60 min three times a week. Before and after training, blood was analyzed for glucose homeostasis, T4, and TSH. Data were subjected to analysis by paired t-test and covariance analysis at the p<0.05 level.

RESULTS

The exercise training intervention reduced the FBS and insulin significantly (p=0.000). The growth hormone (GH) index was increased significantly only in the experimental group (p=0.037) whereas no significant variations occurred in the insulin-like growth factor-1 (p=0.712). It was also found that TSH and T4 change in the experimental group as compared to the pre-test.

CONCLUSIONS

Water-based rhythmic exercise training may improve blood glucose homeostasis, TSH, and T4.

Comparing prophylactic effect of exercise and metformin on cognitive brain functions in rats with type 3 diabetes mellitus

Introduction

Type 2 diabetes mellitus (DM) and Alzheimer's disease (AD) are two major medical conditions that constitute a significant financial burden on most healthcare systems. Due to AD sharing "insulin resistance" mechanistic features with DM, some scientists have proposed "type 3 DM" terminology for it. This study aims to compare the prophylactic effect of exercise and metformin on cognitive brain functions in rats with type 3 DM.

Material and methods

Two groups of rats were included in the study: the control group (n = 15) and the streptozotocin-induced type 2 diabetic group (n = 45). The diabetic group was subdivided into three equal subgroups: a sedentary non-treated diabetic group, an exercised group, and a metformin-treated group. We estimated step-down avoidance task latency, serum glucose, insulin, free fatty acids (FFA), cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides (TG), brain Aβ-42 and glucose, histological changes by toluidine blue, and immunohistochemistry for brain Aβ-42 and tau-positive cells.

Results

Serum glucose, FFA, TG, cholesterol, LDL, brain Aβ-42, brain glucose, the number of hippocampal dark and degenerated cells, and brain Aβ-42 and tau-positive cells, were all significantly lower. In contrast, serum insulin and HDL, the number of hippocampal granular cells, and latency of the step-down avoidance task were significantly higher in exercised and metformin-treated groups compared to the diabetic group. There were significantly higher values of serum insulin and brain/plasma glucose ratio and number of brain tau-positive cells in the metformin-treated group than in the exercised group.

Conclusions

We can conclude that exercise can be as effective as metformin regarding prophylaxis against the deleterious effects of type 3 DM on cognitive brain functions.

Mitochondrial Dysfunction, Insulin Resistance, and Potential Genetic Implications

Insulin resistance (IR) is fundamental to the development of type 2 diabetes (T2D) and is present in most prediabetic (preDM) individuals. Insulin resistance has both heritable and environmental determinants centered on energy storage and metabolism. Recent insights from human genetic studies, coupled with comprehensive in vivo and ex vivo metabolic studies in humans and rodents, have highlighted the critical role of reduced mitochondrial function as a predisposing condition for ectopic lipid deposition and IR. These studies support the hypothesis that reduced mitochondrial function, particularly in insulin-responsive tissues such as skeletal muscle, white adipose tissue, and the liver, is inextricably linked to tissue and whole body IR through the effects on cellular energy balance. Here we discuss these findings as well as address potential mechanisms that serve as the nexus between mitochondrial malfunction and IR.