The Regulation of Fat Metabolism During Aerobic Exercise

Adipose Kiss1 controls aerobic exercise-related adaptive responses in adipose tissue energy homeostasis

Kisspeptin signaling regulates energy homeostasis. Adiposity is the principal source and receiver of peripheral Kisspeptin, and adipose Kiss1 metastasis suppressor (Kiss1) gene expression is stimulated by exercise. However, whether the adipose Kiss1 gene regulates energy homeostasis and plays a role in adaptive alterations during prolonged exercise remains unknown. Here, we investigated the role of Kiss1 role in mice and adipose tissues and the adaptive changes it induces after exercise, using adipose-specific Kiss1 knockout (Kiss1adipoq-/-) and adeno-associated virus-induced adipose tissue Kiss1-overexpressing (Kiss1adipoq over) mice. We found that adipose-derived kisspeptin signal regulates lipid and glucose homeostasis to maintain systemic energy homeostasis, but in a sex-dependent manner, with more pronounced metabolic changes in female mice. Kiss1 regulated adaptive alterations of genes and proteins in tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OxPhos) pathways in female gWAT following prolonged aerobic exercise. We could further show that adipose Kiss1 deficiency leads to reduced peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α) protein content of soleus muscle and maximum oxygen uptake (VO2 max) of female mice after prolonged exercise. Therefore, adipose Kisspeptin may be a novel adipokine that increases organ sensitivity to glucose, lipids, and oxygen following exercise.

iMPAQT reveals that adequate mitohormesis from TFAM overexpression leads to life extension in mice

Mitochondrial transcription factor A, TFAM, is essential for mitochondrial function. We examined the effects of overexpressing the TFAM gene in mice. Two types of transgenic mice were created: TFAM heterozygous (TFAM Tg) and homozygous (TFAM Tg/Tg) mice. TFAM Tg/Tg mice were smaller and leaner notably with longer lifespans. In skeletal muscle, TFAM overexpression changed gene and protein expression in mitochondrial respiratory chain complexes, with down-regulation in complexes 1, 3, and 4 and up-regulation in complexes 2 and 5. The iMPAQT analysis combined with metabolomics was able to clearly separate the metabolomic features of the three types of mice, with increased degradation of fatty acids and branched-chain amino acids and decreased glycolysis in homozygotes. Consistent with these observations, comprehensive gene expression analysis revealed signs of mitochondrial stress, with elevation of genes associated with the integrated and mitochondrial stress responses, including Atf4, Fgf21, and Gdf15. These found that mitohormesis develops and metabolic shifts in skeletal muscle occur as an adaptive strategy.

The role of lipid metabolism in osteoporosis: Clinical implication and cellular mechanism

In recent years, researchers have become focused on the relationship between lipids and bone metabolism balance. Moreover, many diseases related to lipid metabolism disorders, such as nonalcoholic fatty liver disease, atherosclerosis, obesity, and menopause, are associated with osteoporotic phenotypes. It has been clinically observed in humans that these lipid metabolism disorders promote changes in osteoporosis-related indicators bone mineral density and bone mass. Furthermore, similar osteoporotic phenotype changes were observed in high-fat and high-cholesterol-induced animal models. Abnormal lipid metabolism (such as increased oxidized lipids and elevated plasma cholesterol) affects bone microenvironment homeostasis via cross-organ communication, promoting differentiation of mesenchymal stem cells to adipocytes, and inhibiting commitment towards osteoblasts. Moreover, disturbances in lipid metabolism affect the bone metabolism balance by promoting the secretion of cytokines such as receptor activator of nuclear factor-kappa B ligand by osteoblasts and stimulating the differentiation of osteoclasts. Conclusively, this review addresses the possible link between lipid metabolism disorders and osteoporosis and elucidates the potential modulatory mechanisms and signaling pathways by which lipid metabolism affects bone metabolism balance. We also summarize the possible approaches and prospects of intervening lipid metabolism for osteoporosis treatment.

Effects of different training models and subsequent exercise cessation on adipose tissue and associated variables

BACKGROUND

The General Adaptation Syndrome and the supercompensation Model are concepts widely applied in exercise science. Considering that fat is essential for tissue and the main energy source during continuous moderate-intensity exercise (MICE), the hypothesis arises that this type of effort may pay off after a detraining period.

OBJECTIVE

This study aimed to investigate how different exercise models, followed by a period of detraining, affected adipose tissue cellularity in adult rats. Two specific models were examined: moderate-intensity continuous exercise (MICE) and high-intensity intermittent exercise (HIIT).

MATERIALS AND METHODS

This is an experimental study in which rats were allocated into three groups: i) Continuous moderate-intensity exercise (MICE); ii) High-intensity intermittent exercise (HIIT); and iii) Control group (GC). Data were collected in three moments, namely: baseline values (T1), after which the animals exercised on a treadmill for eight weeks (T2) and then were followed up for four weeks after interruption of physical exercise (T3). For statistical analysis, a two-way analysis of variance (ANOVA) was performed, with Tukey's post-hoc for the group (GC, MICE, or HIIT) and Bonferroni's for the moment (T1, T2 and T3).

RESULTS

Regarding the periepididymal mass, GC showed an increase of 45% in T3 compared to T2. The HIIT and MICE groups had lower T3 values when compared to the CG. Comparing groups relative to the delta variation between T2 and T3 showed a difference in periepididymal mass (p = 0.012), with HIIT showing lower values than CG (p = 0.009). Analysis of the number of periepididymal adipocytes showed that HIIT (p < 0.001) and GC (p = 0.003) captured smaller numbers of cells than MICE.

CONCLUSION

In conclusion, our findings demonstrated positive effects of both interventions (HIIT and MICE) in the control of periepididymal adipose tissue mass of adult rats after 4 weeks of exercise interruption, with less mass gain in HIIT. More adipocytes were observed in MICE compared to HIIT and GC. These results suggest that both exercise models helped control fat accumulation, even after detraining.

Vigorous physical activity and weight status in school-aged children: a cross-sectional study

Aim

To explore the association between VPA and weight status in adolescents.

Methods

The 2017/2018 Health Behavior in School-aged Children survey (HBSC) targeted children and adolescents aged 11, 13 and 15. A systematic multistage stratified cluster randomized sampling method was used in each participating country. The 2017/2018 survey enrolled over 240,951 adolescents across 45 countries and regions. Frequency of VPA, weight status and confounding factors were collected using a self-reported questionnaire.

Results

Compared to daily VPA, less frequent VPA was linked to higher odds of obesity. For example, those who participating in VPA for 4-6 times a week (OR = 1.10, 95% CI = 1.06-1.13), 2-3 times a week (OR = 1.21, 95% CI = 1.17-1.25), or once a week (OR = 1.21, 95% CI = 1.16-1.25) all have higher odds of abnormal weight status. For boys, the frequency of 4-6 times a week (OR = 1.09, 95% CI = 1.04-1.13), 2-3 times a week (OR = 1.22, 95% CI = 1.17-1.27), or once a week (OR = 1.25, 95% CI = 1.19-1.32) were associated with higher odds of abnormal weight status. For girls, those who participating in VPA 4-6 times a week (OR = 1.11, 95% CI = 1.06-1.16), 2-3 times a week (OR = 1.20, 95% CI = 1.14-1.25), or once a week (OR = 1.17, 95% CI = 1.11-1.23) all have higher odds of abnormal weight status (i.e., overweight or obesity).

Conclusion

This population-based study suggests that infrequent VPA participation is associated with unhealthy weight status in adolescents compared to their physically active counterparts. Additionally, this association remains consistent in both boys and girls.

An epigenome-wide association study of waist circumference in Chinese monozygotic twins

OBJECTIVES

Central obesity poses significant health risks because it increases susceptibility to multiple chronic diseases. Epigenetic features such as DNA methylation may be associated with specific obesity traits, which could help us understand how genetic and environmental factors interact to influence the development of obesity. This study aims to identify DNA methylation sites associated with the waist circumference (WC) in Northern Han Chinese population, and to elucidate potential causal relationships.

METHODS

A total of 59 pairs of WC discordant monozygotic twins (ΔWC >0) were selected from the Qingdao Twin Registry in China. Generalized estimated equation model was employed to estimate the methylation levels of CpG sites on WC. Causal relationships between methylation and WC were assessed through the examination of family confounding factors using FAmiliaL CONfounding (ICE FALCON). Additionally, the findings of the epigenome-wide analysis were corroborated in the validation stage.

RESULTS

We identified 26 CpG sites with differential methylation reached false discovery rate (FDR) < 0.05 and 22 differentially methylated regions (slk-corrected p < 0.05) strongly linked to WC. These findings provided annotations for 26 genes, with notable emphasis on MMP17, ITGA11, COL23A1, TFPI, A2ML1-AS1, MRGPRE, C2orf82, and NINJ2. ICE FALCON analysis indicated the DNA methylation of ITGA11 and TFPI had a causal effect on WC and vice versa (p < 0.05). Subsequent validation analysis successfully replicated 10 (p < 0.05) out of the 26 identified sites.

CONCLUSIONS

Our research has ascertained an association between specific epigenetic variations and WC in the Northern Han Chinese population. These DNA methylation features can offer fresh insights into the epigenetic regulation of obesity and WC as well as hints to plausible biological mechanisms.

PGC-1α activation boosts exercise-dependent cellular response in the skeletal muscle

The role of Peroxisome proliferator-activated receptor-gamma coactivator alpha (PGC-1α) in fat metabolism is not well known. In this study, we compared the mechanisms of muscle-specific PGC-1α overexpression and exercise-related adaptation-dependent fat metabolism. PGC-1α trained (PGC-1α Ex) and wild-trained (wt-ex) mice were trained for 10 weeks, five times a week at 30 min per day with 60 percent of their maximal running capacity. The PGC-1α overexpressed animals exhibited higher levels of Fibronectin type III domain-containing protein 5 (FNDC5), 5' adenosine monophosphate-activated protein kinase alpha (AMPK-α), the mammalian target of rapamycin (mTOR), Sirtuin 1 (SIRT1), Lon protease homolog 1 (LONP1), citrate synthase (CS), succinate dehydrogenase complex flavoprotein subunit A (SDHA), Mitofusin-1 (Mfn1), endothelial nitric oxide synthase (eNOS), Hormone-sensitive lipase (HSL), adipose triglyceride lipase (ATGL), G protein-coupled receptor 41 (GPR41), and Phosphatidylcholine Cytidylyltransferase 2 (PCYT2), and lower levels of Sirtuin 3 (SIRT3) compared to wild-type animals. Exercise training increased the protein content levels of SIRT1, HSL, and ATGL in both the wt-ex and PGC-1α trained groups. PGC-1α has a complex role in cellular signaling, including the upregulation of lipid metabolism-associated proteins. Our data reveals that although exercise training mimics the effects of PGC-1α overexpression, it incorporates some PGC-1α-independent adaptive mechanisms in fat uptake and cell signaling.

Combined Aerobic Exercise with Intermittent Fasting Is Effective for Reducing mTOR and Bcl-2 Levels in Obese Females

The integration of combined aerobic exercise and intermittent fasting (IF) has emerged as a strategy for the prevention and management of obesity, including its associated health issues such as age-related metabolic diseases. This study aimed to examine the potential of combined aerobic exercise and IF as a preventative strategy against cellular senescence by targeting mTOR and Bcl-2 levels in obese females. A total of 30 obese women, aged 23.56 ± 1.83 years, body fat percentage (FAT) 45.21 ± 3.73% (very high category), BMI 30.09 ± 3.74 kg/m2 were recruited and participated in three different types of interventions: intermittent fasting (IF), exercise (EXG), and a combination of intermittent fasting and exercise (IFEXG). The intervention program was carried out 5x/week for 2 weeks. We examined mTOR and Bcl-2 levels using ELISA kits. Statistical analysis used the one-way ANOVA test and continued with Tukey's HSD post hoc test, with a significance level of 5%. The study results showed that a combination of aerobic exercise and IF significantly decreased mTOR levels (-1.26 ± 0.79 ng/mL) compared to the control group (-0.08 ± 1.33 ng/mL; p ≤ 0.05). However, combined aerobic exercise and IF did not affect Bcl-2 levels significantly (-0.07 ± 0.09 ng/mL) compared to the control group (0.01 ± 0.17 ng/mL, p ≥ 0.05). The IF-only group, exercise-only group, and combined group all showed a significant decrease in body weight and fat mass compared to the control group (p ≤ 0.05). However, the combined aerobic exercise and IF program had a significant effect in reducing the total percentage of body fat and fat mass compared to the IF-only group (p ≤ 0.05). Therefore, it was concluded that the combined intermittent fasting and exercise group (IFEXG) undertook the most effective intervention of the three in terms of preventing cellular senescence, as demonstrated by decreases in the mTOR level, body weight, and fat mass. However, the IFEXG did not present reduced Bcl-2 levels.

Effects of CurraNZ, a New Zealand Blackcurrant Extract during 1 Hour of Treadmill Running in Female and Male Marathon des Sables Athletes in Hot Conditions: Two Case Studies

Four weeks before competition in the 2023 Marathon des Sables, a 6-stage, ~250 km running event in the Sahara Desert, we examined the effects of a 7-day intake of New Zealand blackcurrant extract (210 mg anthocyanins per day) on 1 h treadmill running-induced physiological and metabolic responses in the heat (~34 °C, relative humidity: ~30%) in non-acclimatized amateur female and male athletes (age: 23, 38 yrs, BMI: 24.2, 28.4 kg·m-2, body fat%: 29.2, 18.8%, V˙O2max: 50.1, 52.1 mL·kg-1·min-1). During the 1 h run at 50%V˙O2max (speed female: 7.3, male: 7.5 km·h-1), indirect calorimetry was used, and heart rate was recorded at 15 min intervals with core temperature monitoring (0.05 Hz). The 1 h runs took place 3 h after a light breakfast and 2 h after intake of the final dose of New Zealand blackcurrant extract with water allowed ad libitum during the run. The New Zealand blackcurrant extract had no effects on the female athlete. The respiratory exchange ratio (RER) of the female athlete in the non-supplement control condition was 0.77 ± 0.01, indicating an existing ~77% contribution of fat oxidation to the energy requirements. In the male athlete, during 1 h of running, fat oxidation was higher by 21% (p < 0.01), carbohydrate oxidation was 31% lower (p = 0.05), RER was 0.03 units lower (p = 0.04), and core temperature was 0.4 °C lower (p < 0.01) with no differences for heart rate, minute ventilation, oxygen uptake, and carbon dioxide production for the New Zealand blackcurrant condition compared to the non-supplement control condition. Seven-day intake of New Zealand blackcurrant extract (210 mg anthocyanins per day) provided beneficial physiological and metabolic responses during exertional heat stress by 1 h of indoor (~34 °C) treadmill running in a male Marathon des Sables athlete 4 weeks before competition. Future work is required to address whether New Zealand blackcurrant provides a nutritional ergogenic effect for Marathon des Sables athletes during long-duration running in the heat combined with personalized nutrition.

Genotypic and Allelic Distribution of the CD36 rs1761667 Polymorphism in High-Level Moroccan Athletes: A Pilot Study

Previous studies have shown that variations in the CD36 gene may affect phenotypes associated with fat metabolism as the CD36 protein facilitates the transport of fatty acids to the mitochondria for oxidation. However, no previous study has tested whether variations in the CD36 gene are associated with sports performance. We investigated the genotypic and allelic distribution of the single-nucleotide polymorphism (SNP) rs1761667 in the CD36 gene in elite Moroccan athletes (cyclists and hockey players) in comparison with healthy non-athletes of the same ethnic origin. Forty-three Moroccan elite male athletes (nineteen cyclists and twenty-four field hockey players) belonging to the national teams of their respective sports (athlete group) were compared to twenty-eight healthy, active, male university students (control group). Genotyping of the CD36 rs1761667 (G>A) SNP was performed via polymerase chain reaction (PCR) and Sanger sequencing. A chi-square (χ2) test was used to assess the Hardy-Weinberg equilibrium (HWE) and to compare allele and genotype frequencies in the "athlete" and "control" groups. The genotypic distribution of the CD36 rs1761667 polymorphism was similar in elite athletes (AA: 23.81, AG: 59.52, and GG: 16.67%) and controls (AA: 19.23, AG: 69.23, and GG: 11.54%; χ2 = 0.67, p = 0.71). However, the genotypic distribution of the CD36 rs1761667 polymorphism was different between cyclists (AA: 0.00, AG: 72.22, and GG: 27.78%) and hockey players (AA: 41.67, AG: 50.00, and GG: 8.33%; χ2 = 10.69, p = 0.004). Specifically, the frequency of the AA genotype was significantly lower in cyclists than in hockey players (p = 0.02). In terms of allele frequency, a significant difference was found between cyclists versus field hockey players (χ2 = 7.72, p = 0.005). Additionally, there was a predominance of the recessive model in cyclists over field hockey players (OR: 0.00, 95% CI: 0.00-0.35, p = 0.002). Our study shows a significant difference between cyclists and field hockey players in terms of the genotypic and allelic frequency of the SNP rs1761667 of the CD36 gene. This divergence suggests a probable association between genetic variations in the CD36 gene and the type of sport in elite Moroccan athletes.

Aerobic training with moderate or high doses of vitamin D improve liver enzymes, LXRα and PGC-1α levels in rats with T2DM

Dysregulation of key transcription factors involved in hepatic energy metabolism, such as peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) and liver X receptor alpha (LXRα), has been observed in T2DM. The present study aims to investigate the effects of aerobic training and vitamin D supplementation on liver enzyme levels and the levels of PGC-1α and LXRα proteins in hepatocytes, in a rat model of T2DM. The study involved 56 male Wistar rats, divided into two groups: one was non-diabetic and acted as a control group (n = 8), and the other had induced diabetes (n = 48). The diabetic rats were then split into six subgroups: two groups received high or moderate doses of vitamin D and aerobic training (D + AT + HD and D + AT + MD); two groups received high or moderate doses of vitamin D alone (D + HD and D + MD); one group underwent aerobic training with vehicle (sesame oil; D + AT + oil), and one group was a diabetic control receiving only sesame oil (oil-receiving). The D + AT + HD and D + HD groups received 10,000 IU of vitamin D, while the D + AT + MD and D + MD groups received 5000 IU of vitamin D once a week by injection. The D + AT + oil group and the sham group received sesame oil. After eight weeks of treatment, body weight, BMI, food intake, serum insulin, glucose, 25-hydroxyvitamin D, ALT, AST, and visceral fat were measured. The levels of PGC-1α and LXRα proteins in the liver was assessed by western blotting. Statistical analysis was performed using the paired t-test, one-way analysis of variance (ANOVA), and the Tukey post hoc test at a significance level of P < 0.05. Body weight, food intake, and BMI decreased significantly in the D + AT + HD, D + AT + MD, D + AT + oil, D + HD, and D + MD groups with the highest reduction being observed in body weight and BMI in the D + AT + HD group. The D + AT + HD group exhibited the lowest levels of insulin, glucose, and HOMA-IR while the D + C group exhibited the highest levels among the diabetic groups. The D + AT + HD and D + AT + MD groups had lower levels of ALT and AST enzymes compared to the other groups with no significant difference between D + AT + HD and D + AT + MD. D + AT + HD (p = 0.001), D + AT + MD (p = 0.001), D + HD (p = 0.023), D + MD (p = 0.029), and D + AT + oil (p = 0.011) upregulated LXRα compared to D + C. Among these groups, D + AT + HD exhibited a more profound upregulation of LXRα than D + AT + MD, D + AT + oil, D + HD, and D + MD (p = 0.005; p = 0.002, p = 0.001, and p = 0.001, respectively). Similarly, D + AT + HD showed a more notable upregulation of PGC-1α compared to D + AT + oil, D + HD, and D + MD (p = 0.002; p = 0.001, and p = 0.001, respectively). Pearson correlation tests showed significant and negative correlations between serum 25-hydroxyvitamin levels and both visceral fat (r = - 0.365; p = 0.005) and HOMA-IR (r = - 0.118; p = 0.009); while positive and significant correlations between the liver-to-bodyweight ratio with both ALT and AST enzymes and also between QUICKI levels with LXRα (r = 0.578; p = 0.001) and PGC-1α (r = 0.628; p = 0.001). Combined administration of aerobic training and vitamin D supplementation potentially improves liver enzymes in type-2 diabetic rats that were simultaneous with upregulating the levels of PGC-1α and LXRα proteins in hepatocytes. These improvements were more significant when combining exercise with high-dose vitamin D supplementation. This study highlights the potential of this combination therapy as a new diabetes treatment strategy.

Genetics of Exercise and Diet-Induced Fat Loss Efficiency: A Systematic Review

Physical exercise and dieting are well-known and effective methods for fat loss and improving cardiovascular health. However, different individuals often react differently to the same exercise regimen or dietary plan. While specific individuals may undergo substantial fat loss, others may observe only limited effects. A wide range of inter-individual variability in weight gain and changes in body composition induced by physical exercises and diets led to an investigation into the genetic factors that may contribute to the individual variations in such responses. This systematic review aimed at identifying the genetic markers associated with fat loss resulting from diet or exercise. A search of the current literature was performed using the PubMed database. Forty-seven articles met the inclusion criteria when assessing genetic markers associated with weight loss efficiency in response to different types of exercises and diets. Overall, we identified 30 genetic markers of fat-loss efficiency in response to different kinds of diets and 24 in response to exercise. Most studies (n = 46) used the candidate gene approach. We should aspire to the customized selection of exercise and dietary plans for each individual to prevent and treat obesity.

Type IIx muscle fibers are related to poor body composition, glycemic and lipidemic blood profiles in young females: the protective role of type I and IIa muscle fibers

PURPOSE

The aim of the present study was to investigate the association between muscle fiber composition, body composition, resting glycemic-lipidemic blood profiles, in apparently healthy, young, active females.

METHODS

Thirty-four young healthy female volunteers were allocated into two groups, depending on their Vastus Lateralis type IIx muscle fibers percent cross-sectional area (%CSA; H: high type IIx %CSA; L: low type IIx %CSA). Body composition was determined via dual-energy X-ray absorptiometry. Venous blood samples were collected for the determination of resting serum glucose, Insulin, Apo-A1, HOMA-IR, triglycerides (TG), total cholesterol (TC), High-density lipoprotein (HDL-C), and Low-density lipoprotein (LDL-C) concentrations. Nutritional intake was also evaluated.

RESULTS

Individuals of the H group have significantly higher body mass, body fat percentage-mass, and resting blood indices of glycemic and lipidemic profiles, compared to those of L group (p < 0.001). Increased type IIx and low type I, IIa muscle fibers %CSAs were linked with poorer body composition, glycemic and lipidemic blood profiles (r: - 0.722 to 0.740, p < 0.001). Linear regression analyses revealed that the impact of muscle fibers %CSA (B coefficients ranged between - 0.700 and 0.835) on the above parameters, was at least, of the same or even of greater magnitude as that of body composition and daily nutritional intake (B: - 0.700 to 0.666).

CONCLUSION

Increased type IIx and low Type I, IIa %CSAs are associated with poorer body composition and glycemic-lipidemic profiles in young healthy females. The contribution of the muscle fiber %CSA on health status seems to be comparable to that of nutrition and body composition.

Follistatin-like 1 is a myokine regulating lipid mobilization during endurance exercise and recovery

OBJECTIVE

The aim of this study was to investigate the role of the follistatin-like 1 (Fstl1) and disco-interacting protein 2 homolog A (DIP2a) axis in relation to lipid metabolism during and after endurance exercise and to elucidate the mechanisms underlying the metabolic effects of Fstl1 on adipocytes, considering its regulation by exercise and muscle mass and its link to obesity.

METHODS

Twenty-nine sedentary males participated in endurance exercise, and blood samples were collected during and after the exercise. Body composition, Fstl1, glycerol, epinephrine, growth hormone, and atrial natriuretic peptide were measured. 3T3-L1 adipocytes, with or without DIP2a knockdown, were treated with Fstl1 to assess glycerol release, cyclic AMP/cyclic GMP production, and hormone sensitive lipase phosphorylation. The association between DIP2a gene expression levels in human adipose tissues and exercise-induced lipolysis was examined.

RESULTS

Fstl1 levels significantly increased during endurance exercise and following recovery, correlating with lean body mass and lipolysis. In 3T3-L1 adipocytes, Fstl1 increased glycerol release, cyclic GMP production, and hormone sensitive lipase activation, but these effects were attenuated by DIP2a knockdown. DIP2a gene expression in human adipose tissues correlated with serum glycerol concentrations during endurance exercise.

CONCLUSIONS

Fstl1 is a myokine facilitating lipid mobilization during and after endurance exercise through DIP2a-mediated lipolytic effects in adipocytes.

Physical exercise in kidney disease: A commonly undervalued treatment modality

BACKGROUND

Physical inactivity has been identified as a risk factor for multiple disorders and a strong association exists between chronic kidney disease (CKD) and a sedentary lifestyle. Even though physical activity is crucial in the development and progression of disease, the general focus of the current medical practice is the pharmacological perspective of diseases with inadequate emphasis on lifestyle intervention.

METHODS

In this narrative review we explain the pathophysiological mechanisms underlying the beneficial effects of physical exercise on CKD in addition to discussing the clinical studies and trials centred on physical exercise in patients with CKD.

RESULTS

Physical activity influences several pathophysiological mechanisms including inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism. While exercise can initially induce stress responses like inflammation and oxidative stress, long-term physical activity leads to protective countermeasures and overall improved health. Trials in pre-dialysis CKD patients show that exercise can lead to reductions in body weight, inflammation markers and fasting plasma glucose. Furthermore, it improves patients' functional capacity, cardiorespiratory fitness and quality of life. The effects of exercise on kidney function have been inconsistent in these trials. In haemodialysis, peritoneal dialysis and kidney transplant patients exercise interventions improve cardiorespiratory fitness, walking capacity and quality of life. Combined training shows the best performance to increase peak oxygen uptake in haemodialysis patients. In kidney transplant recipients, exercise improves walking performance, quality of life and potentially arterial stiffness. However, exercise does not affect glucose metabolism, serum cholesterol and inflammation biomarkers. Long-term, adequately powered trials are needed to determine the long-term feasibility, and effects on quality of life and major clinical outcomes, including mortality and cardiovascular risk, in all CKD stages and particularly in kidney transplant patients, a scarcely investigated population.

CONCLUSION

Physical exercise plays a crucial role in ameliorating inflammation, oxidative stress, vascular function, immune response and macromolecular metabolism, and contributes significantly to the quality of life for patients with CKD, irrespective of the treatment and stage. Its direct impact on kidney function remains uncertain. Further extensive, long-term trials to conclusively determine the effect of exercise on major clinical outcomes such as mortality and cardiovascular risk remain a research priority.

Exerkines, Nutrition, and Systemic Metabolism

The cornerstones of good health are exercise, proper food, and sound nutrition. Physical exercise should be a lifelong routine, supported by proper food selections to satisfy nutrient requirements based on energy needs, energy management, and variety to achieve optimal metabolism and physiology. The human body is sustained by intermediary and systemic metabolism integrating the physiologic processes for cells, tissues, organs, and systems. Recently, interest in specific metabolites, growth factors, cytokines, and hormones called exerkines has emerged to explain cooperation between nutrient supply organs and the brain during exercise. Exerkines consist of different compounds described as signaling moiety released during and after exercise. Examples of exerkines include oxylipin 12, 13 diHOME, lipid hormone adiponectin, growth factor BDNF, metabolite lactate, reactive oxygen species (ROS), including products of fatty acid oxidation, and cytokines such as interleukin-6. At this point, it is believed that exerkines are immediate, fast, and long-lasting factors resulting from exercise to support body energy needs with an emphasis on the brain. Although exerkines that are directly a product of macronutrient metabolism such as lactate, and result from catabolism is not surprising. Furthermore, other metabolites of macronutrient metabolism seem to be candidate exerkines. The exerkines originate from muscle, adipose, and liver and support brain metabolism, energy, and physiology. The purpose of this review is to integrate the actions of exerkines with respect to metabolism that occurs during exercise and propose other participating factors of exercise and brain physiology. The role of diet and macronutrients that influence metabolism and, consequently, the impact of exercise will be discussed. This review will also describe the evidence for PUFA, their metabolic and physiologic derivatives endocannabinoids, and oxylipins that validate them being exerkines. The intent is to present additional insights to better understand exerkines with respect to systemic metabolism.

Is Physical Activity an Efficient Strategy to Control the Adverse Effects of Persistent Organic Pollutants in the Context of Obesity? A Narrative Review

Obesity affects nearly 660 million adults worldwide and is known for its many comorbidities. Although the phenomenon of obesity is not fully understood, science regularly reveals new determinants of this pathology. Among them, persistent organic pollutants (POPs) have been recently highlighted. Mainly lipophilic, POPs are normally stored in adipose tissue and can lead to adverse metabolic effects when released into the bloodstream. The main objective of this narrative review is to discuss the different pathways by which physical activity may counteract POPs' adverse effects. The research that we carried out seems to indicate that physical activity could positively influence several pathways negatively influenced by POPs, such as insulin resistance, inflammation, lipid accumulation, adipogenesis, and gut microbiota dysbiosis, that are associated with the development of obesity. This review also indicates how, through the controlled mobilization of POPs, physical activity could be a valuable approach to reduce the concentration of POPs in the bloodstream. These findings suggest that physical activity should be used to counteract the adverse effects of POPs. However, future studies should accurately assess its impact in specific situations such as bariatric surgery, where weight loss promotes POPs' blood release.

Effect of Acute Caffeine Intake on Fat Oxidation Rate during Fed-State Exercise: A Systematic Review and Meta-Analysis

Pre-exercise intake of caffeine (from ~3 to 9 mg/kg) has been demonstrated as an effective supplementation strategy to increase fat oxidation during fasted exercise. However, a pre-exercise meal can alter the potential effect of caffeine on fat oxidation during exercise as caffeine modifies postprandial glycaemic and insulinemic responses. Hypothetically, the effect of caffeine on fat oxidation may be reduced or even withdrawn during fed-state exercise. The present systematic review aimed to meta-analyse investigations on the effect of acute caffeine intake on the rate of fat oxidation during submaximal aerobic exercise performed in the fed state (last meal < 5 h before exercise). A total of 18 crossover trials with randomised and placebo-controlled protocols and published between 1982 and 2021 were included, with a total of 228 participants (185 males and 43 females). Data were extracted to compare rates of fat oxidation during exercise with placebo and caffeine at the same exercise intensity, which reported 20 placebo-caffeine pairwise comparisons. A meta-analysis of the studies was performed, using the standardised mean difference (SMD) estimated from Hedges' g, with 95% confidence intervals (CI). In comparison with the placebo, caffeine increased the rate of fat oxidation during fed-state exercise (number of comparisons (n) = 20; p = 0.020, SMD = 0.65, 95% CI = 0.20 to 1.20). Only studies with a dose < 6 mg/kg of caffeine (n = 13) increased the rate of fat oxidation during fed-state exercise (p = 0.004, SMD = 0.86, 95% CI = 0.27 to 1.45), while no such effect was observed in studies with doses ≥6 mg/kg (n = 7; p = 0.97, SMD = -0.03, 95% CI = -1.40 to 1.35). The effect of caffeine on fat oxidation during fed-state exercise was observed in active untrained individuals (n = 13; p < 0.001, SMD = 0.84, 95% CI = 0.39 to 1.30) but not in aerobically trained participants (n = 7; p = 0.27, SMD = 0.50, 95% CI = -0.39 to 1.39). Likewise, the effect of caffeine on fat oxidation was observed in caffeine-naïve participants (n = 9; p < 0.001, SMD = 0.82, 95% CI = 0.45 to 1.19) but not in caffeine consumers (n = 3; p = 0.54, SMD = 0.57, 95% CI = -1.23 to 2.37). In conclusion, acute caffeine intake in combination with a meal ingested within 5 h before the onset of exercise increased the rate of fat oxidation during submaximal aerobic exercise. The magnitude of the effect of caffeine on fat oxidation during fed-state exercise may be modulated by the dose of caffeine administered (higher with <6 mg/kg than with ≥6 mg/kg), participants' aerobic fitness level (higher in active than in aerobically trained individuals), and habituation to caffeine (higher in caffeine-naïve than in caffeine consumers).

Supplementation with food-derived oligopeptides promotes lipid metabolism in young male cyclists: a randomized controlled crossover trial

BACKGROUND

Accumulation of body fat and dyslipidemia are associated with the development of obesity and cardiometabolic diseases. Moreover, the degree to which lipids can be metabolized has been cited as a determinant of cardiometabolic health and prolonged endurance capacity. In the backdrop of increasing obesity and cardiometabolic diseases, lipid metabolism and its modulation by physical activity, dietary adjustments, and supplementation play a significant role in maintaining health and endurance. Food-derived oligopeptides, such as rice and soybean peptides, have been shown to directly regulate abnormal lipid metabolism or promote hypolipidemia and fat oxidation in cell culture models, animal models, and human studies. However, whether supplementation with oligopeptides derived from multiple food sources can promote lipid degradation and fat oxidation in athletes remains unclear. Therefore, in a randomized controlled crossover trial, we investigated the impact of food-derived oligopeptide supplementation before and during exercise on lipid metabolism in young male cyclists.

METHODS

Sixteen young male cyclists (age: 17.0 ± 1.0 years; height: 178.4 ± 6.9 cm; body mass: 68.7 ± 12.7 kg, body mass index: 21.5 ± 3.4 kg/m2; maximum oxygen uptake: 56.3 ± 5.8 mL/min/kg) participated in this randomized controlled crossover trial. Each participant drank two beverages, one containing a blend of three food-derived oligopeptides (treatment, 0.5 g/kg body weight in total) and the other without (control), with a 2-week washout period between two experiments. The cyclists completed a one-day pattern protocol that consisted of intraday fasting, 30 min of sitting still, 85 min of prolonged exercise plus a 5-min sprint (PE), a short recovery period of 60 min, a 20-min time trial (TT), and recovery till next morning. Blood samples were collected for biochemical analyses of serum lipids and other biomarkers. We analyzed plasma triglyceride species (TGs), free amino acids (FAAs), and tricarboxylic acid (TCA) cycle intermediates using omics methods. In addition, exhaled gas was collected to assess the fat oxidation rate.

RESULTS

Five of 20 plasma FAAs were elevated pre-exercise (pre-Ex) only 20 min after oligopeptide ingestion, and most FAAs were markedly increased post PE and TT. Serum levels of TG and non-esterified fatty acids were lower in the experimental condition than in the control condition at the post PE and TT assessments, respectively. Further, the omics analysis of plasma TGs for the experimental condition demonstrated that most TGs were lower post PE and at the next fasting when compared with control levels. Simultaneously, the fat oxidation rate began to increase only 20 min after ingestion and during the preceding 85 min of PE. Levels of TCA cycle intermediates did not differ between the conditions.

CONCLUSIONS

The study noted that continuous ingestion of food-derived oligopeptides accelerated total body triglyceride breakdown, non-esterified fatty acid uptake, and fat oxidation during both sedentary and exercise states. Elevated circulating and intracellular FAA flux may modulate the selection of substrates for metabolic pathways in conjunction with the release of neuroendocrinological factors that slow down carbohydrate metabolism via acetyl coenzyme A feedback inhibition. This may increase the availability of fatty acids for energy production, with FAAs supplying more substrates for the TCA cycle. The findings of this study provide novel insight into strategies for promoting lipid metabolism in populations with dyslipidemia-related metabolic disorders such as obesity and for improving physiological functioning during endurance training. However, the absence of a non-exercising control group and verification of long-term supplementation effects was a limitation. Future studies will emphasize the impacts of whole protein supplementation as a control and of combined food-derived peptides or oligopeptides with probiotics and healthy food components on lipid metabolism in individuals who exercise.

Effects Of Exercise Training And Chlorogenic Acid Supplementation On Hepatic Lipid Metabolism In Prediabetes Mice

BACKGRUOUND

Since prediabetes is a risk factor for metabolic syndromes, it is important to promote a healthy lifestyle to prevent prediabetes. This study aimed to determine the effects of green coffee (GC), chlorogenic acid (CGA) intake, and exercise training (EX) on hepatic lipid metabolism in prediabetes male C57BL/6 mice.

METHODS

Forty-nine mice were randomly divided into two groups feeding with a normal diet (n=7) or a high-fat diet (HFD, n=42) for 12 weeks. Then, HFD mice were further divided into six groups (n=7/group): control (pre-D), GC, CGA, EX, GC+EX, and CGA+EX. After additional 10 weeks under the same diet, plasma, and liver samples were obtained.

RESULTS

HFD-induced prediabetes conditions with increases in body weight, glucose, insulin, insulin resistance, and lipid profiles were alleviated in all treatment groups. Acsl3, a candidate gene identified through an in silico approach, was lowered in the pre-D group, while treatments partly restored it. HFD induced adverse alterations of de novo lipogenesis- and β oxidation-associated molecules in the liver. However, GC and CGA supplementation and EX reversed or ameliorated these changes. In most cases, GC or CGA supplementation combined with EX has no synergistic effect and the GC group had similar results to the CGA group.

CONCLUSION

These findings suggest that regular exercise is an effective non-therapeutic approach for prediabetes, and CGA supplementation could be an alternative to partially mimic the beneficial effects of exercise on prediabetes.

Metabolomic analysis indicated changes in triacylglycerols' levels as a result of training in Whippet dogs

Regular physical effort produces metabolic changes manifested as adaptation to exercise and increasing performance. In humans these changes have been characterized at metabolome level as depending on the discipline. However, all sports involve some level of changes in protein, carbohydrate and lipid metabolism. Recently, also performance horses have been subjected to metabolic analyses, but similar studies were lacking in sports dogs. In this study we performed the metabolomic analysis in plasma of Whippet dogs regularly trained and competing in coursing events, and untrained dogs of the same breed, fed with the same diet. We have also compared the hematological and blood biochemical results in these two groups of dogs. Basic blood tests indicated that enzymes related to lipid metabolism (lipase and gamma-glutamyltransferase) differed considerably between the groups. Metabolomic analysis of plasma confirmed the metabolic shift expressed as the differences in triacylglycerols levels between training and non-training dogs, aimed at improving the use of fatty acids as a source of energy during exertion. Surprisingly, other classes of metabolites were only hardly changed when comparing training and non-training Whippets.

Energy metabolic mechanisms for high altitude sickness: Downregulation of glycolysis and upregulation of the lactic acid/amino acid-pyruvate-TCA pathways and fatty acid oxidation

Hypobaric hypoxia is often associated with the plateau environment and can lead to altitude sickness or death. The underlying cause is a lack of oxygen, which limits energy metabolism and leads to a compensatory stress response. Although glycolysis is commonly accepted as the primary energy source during clinical hypoxia, our preliminary experiments suggest that hypobaric hypoxia may depress glycolysis. To provide a more comprehensive understanding of energy metabolism under short-term hypobaric hypoxia, we exposed mice to a simulated altitude of 5000 m for 6 or 12 h. After the exposure, we collected blood and liver tissues to quantify the substrates, enzymes, and metabolites involved in glycolysis, lactic acid metabolism, the tricarboxylic acid cycle (TCA), and fatty acid β-oxidation. We also performed transcriptome and enzymatic activity analyses of the liver. Our results show that 6 h of hypoxic exposure significantly increased blood glucose, decreased lactic acid and triglyceride concentrations, and altered liver enzyme activities of mice exposed to hypoxia. The key enzymes in the glycolytic, TCA, and fatty acid β-oxidation pathways were primarily affected. Specifically, the activities of key glycolytic enzymes, such as glucokinase, decreased significantly, while the activities of enzymes in the TCA cycle, such as isocitrate dehydrogenase, increased significantly. Lactate dehydrogenase, pyruvate carboxylase, and alanine aminotransferase were upregulated. These changes were partially restored when the exposure time was extended to 12 h, except for further downregulation of phosphofructokinase and glucokinase. This study demonstrates that acute high altitude hypoxia upregulated the lactic acid/amino acid-pyruvate-TCA pathways and fatty acid oxidation, but downregulated glycolysis in the liver of mice. The results obtained in this study provide a theoretical framework for understanding the mechanisms underlying the pathogenesis of high-altitude sickness in humans. Additionally, these findings have potential implications for the development of prevention and treatment strategies for altitude sickness.

Effects of heat-killed Lactiplantibacillus plantarum TWK10 on exercise performance, fatigue, and muscle growth in healthy male adults

Consumption of Lactiplantibacillus plantarum TWK10 (TWK10) has beneficial probiotic effects, improves exercise endurance performance, regulates body composition, and mitigates aging-related problems in mice and humans. Here, we investigated the effects of heat-killed TWK10 on exercise endurance performance, muscle weight and strength, fatigue, and body composition in a double-blind, placebo-controlled clinical trial. Thirty healthy males aged 20-40 years were assigned to the Control group or heat-killed TWK10 group (TWK10-HK) in a balanced order according to each individual's initial maximal oxygen uptake. After 6-week administration, the exercise endurance time in the TWK10-HK was significantly increased (p = 0.0028) compared with that in the Control group. The grip strength on the right and left hands of the subjects was significantly increased (p = 0.0002 and p = 0.0140, respectively) in the TWK10-HK compared with that in the Control group. Administration of heat-killed TWK10 resulted in a significant increase (p = 0.0275) in muscle weight. After 6-week administration, serum lactate, and ammonia levels were significantly lower in the TWK10-HK group than in the Control group during the exercise and recovery periods. These findings demonstrate that heat-killed TWK10 has significant potential to be used as a postbiotic for humans.

Vitamin D improves the antidiabetic effectiveness of aerobic training via modulation of Akt, PEPCK, and G6Pase expression

BACKGROUND

Although the effect of Vitamin D Supplementation (Vit D) on several chronic diseases has been well conceded, its role in diabetes remains ambiguous. The present study investigated the interactive effects of Aerobic Training (AT) and different Vit D doses on Protein Kinase B (Akt), Phosphoenolpyruvate Carboxylase (PEPCK), and Glucose-6-Phosphatase (G6Pase) protein expressions in hepatocytes of type-2 diabetic rats.

METHODS

Fifty-six male Wistar rats were divided into 2 groups SHAM (non-diabetic control; n = 8), and diabetic (n = 48). Then, diabetic rats were divided into six groups: AT with high doses of Vit D (D + AT + HD), AT with moderate doses of Vit D (D + AT + MD), high doses of Vit D (D + HD), moderate doses of Vit D (D + MD), AT receiving vehicle (sesame oil; D + AT + oil), and control (oil-receiving). D + AT + HD and D + HD groups received 10,000 IU of Vit D; while D + AT + MD and D + MD groups receive 5000 IU of Vit D once a week by injection; D + AT + oil and SHAM groups received sesame oil. Diabetes was induced via intraperitoneal (IP) injection of streptozotocin (50 mg/kg body weight). After 2 months of intervention, serum insulin, glucose, and visceral fat were measured; protein expressions of Akt, PEPCK, and G6Pase were assessed by western blotting. The paired t-test, one-way analysis of variance (One-Way ANOVA), and the Tukey post hoc test were used at the signification level of P < 0.05.

RESULTS

Our data indicate that the diabeticization of rats increased the level of insulin, glucose, and PEPCK and G6Pase protein expressions and decreased the expression of the Akt (P < 0.05 for all variables). Combined AT and moderate or high Vit D significantly reduced body weight (P = 0.001; P = 0.001), body mass index (P = 0.001; P = 0.002), food intake (P = 0.001; P = 0.001) comparing the pre-test with the post-test, respectively. Also, AT and either high or moderate Vit D alone therapies lead to the improvement of the metabolic state, however, their combination had a more significant effect on the treatment of type 2 diabetes.

CONCLUSIONS

Findings from the present study suggested that combined Vit D supplementation and AT successfully improve liver function and attenuate insulin resistance via upregulating Akt and downregulating PEPCK and G6Pase expressions, compared with monotherapy.

Exercise modifies fatty acid perception and metabolism

AIM

Obesity is a major public health issue, which is associated with several chronic diseases. In rodents, voluntary wheel running (VWR) is a type of exercise that influences ingestive behavior. This study aims to investigate the possible function of VWR activity in the perception of fat taste and if it mitigates the immediate effects of fatty acid (FA) ingestion.

METHODS

Male C57BL/6 mice were arbitrarily assigned to either a sedentary (SED) lifestyle or free access to a running wheel after 5 weeks of dietary regimen. Later these mice groups were used in the investigations on fat preference, metabolic tolerance, and electrophysiology. Diet-induced alterations in CD36 and GPR120 expression that are related to fat perception and the capacitative calcium signaling caused by FA in taste bud cells (TBCs) were also examined.

RESULTS

In obese groups, VWR temporarily reduced body weight, demonstrated improvement in preference scores for FA, and recovered from a deterioration in glucose homeostasis. In CD36-positive TBCs, electrophysiological investigations showed alterations in [Ca2+ ]i caused by FA. Further, in the TBCs of circumvallate papillae, there are differences in the expression of the genes CD36 and GPR120 between the active and SED controls. Obese mice also show lower incentive salience for long-chain fatty acids (LCFA) and adapted to the reward system of VWR which may lead to improved incentive salience accredited to wheel running.

CONCLUSION

In conclusion, this study provides the first evidence that VWR causes orosensory adaptations to fat and appears to alter taste preference for LCFAs.

Thyroid Hormone Regulates the Lipid Content of Muscle Fibers, Thus Affecting Physical Exercise Performance

Skeletal muscle (SkM) lipid composition plays an essential role in physiological muscle maintenance and exercise performance. Thyroid hormones (THs) regulate muscle formation and fuel energy utilization by modulating carbohydrates and lipid and protein metabolism. The best-known effects of THs in SkM include the promotion of mitochondrial biogenesis, the fiber-type switch from oxidative to glycolytic fibers, and enhanced angiogenesis. To assess the role of THs on the lipidic composition of SkM fibers, we performed lipidomic analyses of SkM cells and tissues, glucose tolerance experiments, and exercise performance tests. Our data demonstrated that TH treatment induces remodeling of the lipid profile and changes the proportion of fatty acids in SkM. In brief, THs significantly reduced the ratio of stearic/oleic acid in the muscle similar to what is induced by physical activity. The increased proportion of unsaturated fatty acids was linked to an improvement in insulin sensitivity and endurance exercise. These findings point to THs as critical endocrine factors affecting exercise performance and indicate that homeostatic maintenance of TH signals, by improving cell permeability and receptor stability at the cell membrane, is crucial for muscle physiology.

The Positive Effect of Four-Week Combined Aerobic-Resistance Training on Body Composition and Adipokine Levels in Obese Females

Obesity is a metabolic disease that is caused by a lack of physical activity and is associated with an increased risk of chronic inflammation. A total of 40 obese adolescent females with an average age of 21.93 ± 1.35 years and average body mass index (BMI) of 30.81 ± 3.54 kg/m² were enrolled in this study, randomized, and divided into four groups, i.e., control (CTL; n = 10), moderate intensity aerobic training (MAT; n = 10), moderate intensity resistance training (MRT; n = 10), and moderate intensity combined aerobic-resistance training (MCT; n = 10). The enzyme-linked immunosorbent assay (ELISA) kits method was used to analyze the adiponectin and leptin levels between pre-intervention and post-intervention. Statistical analysis was conducted using a paired sample t-test, while correlation analysis between variables used the Pearson product-moment correlation test. Research data showed that MAT, MRT, and MCT significantly increased adiponectin levels and decreased leptin levels compared to the CTL (p ≤ 0.05). The results of the correlation analysis of delta (∆) data showed that an increase in adiponectin levels was significantly negatively correlated with a decrease in body weight (BW) (r = -0.671, p ≤ 0.001), BMI (r = -0.665, p ≤ 0.001), and fat mass (FM) (r = -0.694, p ≤ 0.001) and positively correlated with an increase in skeletal muscle mass (SMM) (r = 0.693, p ≤ 0.001). Whereas, a decrease in leptin levels was significantly positively correlated with a decrease in BW (r = 0.744, p ≤ 0.001), BMI (r = 0.744, p ≤ 0.001), and FM (r = 0.718, p ≤ 0.001) and negatively correlated with an increase in SMM (r = -0.743, p ≤ 0.001). In summary, it can be concluded that our data show that adiponectin levels increased and leptin levels decreased after the intervention of aerobic, resistance, and combined aerobic-resistance training.

Exercise training impacts skeletal muscle remodelling induced by metabolic syndrome in ZSF1 rats through metabolism regulation

Metabolic syndrome (MetS), characterized by a set of conditions that include obesity, hypertension, and dyslipidemia, is associated with increased cardiovascular risk. Exercise training (EX) has been reported to improve MetS management, although the underlying metabolic adaptations that drive its benefits remain poorly understood. This work aims to characterize the molecular changes induced by EX in skeletal muscle in MetS, focusing on gastrocnemius metabolic remodelling. ¹H NMR metabolomics and molecular assays were employed to assess the metabolic profile of skeletal muscle tissue from lean male ZSF1 rats (CTL), obese sedentary male ZSF1 rats (MetS-SED), and obese male ZF1 rats submitted to 4 weeks of treadmill EX (5 days/week, 60 min/day, 15 m/min) (MetS-EX). EX did not counteract the significant increase of body weight and circulating lipid profile, but had an anti-inflammatory effect and improved exercise capacity. The decreased gastrocnemius mass observed in MetS was paralleled with glycogen degradation into small glucose oligosaccharides, with the release of glucose-1-phosphate, and an increase in glucose-6-phosphate and glucose levels. Moreover, sedentary MetS animals' muscle exhibited lower AMPK expression levels and higher amino acids' metabolism such as glutamine and glutamate, compared to lean animals. In contrast, the EX group showed changes suggesting an increase in fatty acid oxidation and oxidative phosphorylation. Additionally, EX mitigated MetS-induced fiber atrophy and fibrosis in the gastrocnemius muscle. EX had a positive effect on gastrocnemius metabolism by enhancing oxidative metabolism and, consequently, reducing susceptibility to fatigue. These findings reinforce the importance of prescribing EX programs to patients with MetS.

The Impact of Aerobic Exercise on HDL Quantity and Quality: A Narrative Review

High-density lipoproteins comprise roughly 25-30% of the circulating proteins involved in the transport of lipids in circulation. These particles differ in size and lipid composition. Recent evidence suggests that the quality of HDL particles (which depends on shape, size and the composition of proteins and lipids determining HDL functionality) may be more important than their quantity. The functionality of HDL is mirrored by its cholesterol efflux activity, as well as its antioxidant (including the protection of LDL against oxidation), anti-inflammatory and antithrombotic properties. The results of many studies and meta-analyses imply the beneficial impact of aerobic exercise on HDL-C levels. Physical activity was found to be usually associated with an increase in HDL cholesterol and a decrease in LDL cholesterol and triglycerides. Exercise, apart from inducing quantitative alterations in serum lipids, exerts a beneficial impact on HDL particle maturation, composition and functionality. The Physical Activity Guidelines Advisory Committee Report underlined the importance of establishing a program recommending exercises that enable attainment of maximal advantage at the lowest level of risk. The aim of this manuscript is to review the impact of different types of aerobic exercise (various intensities and durations) on the level and quality of HDL.

Targeted Lipidomics and Inflammation Response to Six Weeks of Sprint Interval Training in Male Adolescents

Lipids play an important role in coordinating and regulating metabolic and inflammatory processes. Sprint interval training (SIT) is widely used to improve sports performance and health outcomes, but the current understanding of SIT-induced lipid metabolism and the corresponding systemic inflammatory status modification remains controversial and limited, especially in male adolescents. To answer these questions, twelve untrained male adolescents were recruited and underwent 6 weeks of SIT. The pre- and post-training testing included analyses of peak oxygen consumption (VO2peak), biometric data (weight and body composition), serum biochemical parameters (fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triacylglycerol, testosterone, and cortisol), inflammatory markers, and targeted lipidomics. After the 6-week SIT, the serum C-reactive protein (CRP), interleukin (IL)-1β, IL-2, IL-4, IL-10, tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β significantly decreased (p < 0.05), whereas IL-6 and IL-10/TNF-α significantly increased (p < 0.05). In addition, the targeted lipidomics revealed changes in 296 lipids, of which 33 changed significantly (p < 0.05, fold change > 1.2 or <1/1.2). The correlation analysis revealed that the changes in the inflammatory markers were closely correlated with the changes in some of the lipids, such as LPC, HexCer, and FFA. In conclusion, the 6-week SIT induced significant changes in the inflammatory markers and circulating lipid composition, offering health benefits to the population.

Metabolic responses to acute sprint interval exercise training performed after an oral 75-gram glucose load in individuals with overweight/obesity

There is evidence supporting that acute sprint interval training (SIT) might improve metabolic responses to postprandial glucose, but results are inconclusive. The aim of the present study was to explore the effects of acute SIT on metabolic response and substrate utilization in individuals with overweight/obesity after an oral 75-gram glucose challenge. Thirty-three participants with overweight/ obesity (32.7 ± 8.3 years, 24 male, 9 female) participated in the study and a crossover design was followed. After the 75-gram glucose load, participants were randomly allocated to two groups: no exercise (resting) or SIT protocol. Metabolic data including respiratory quotient (RQ) and substrate utilization rates (fats and carbohydrates) were collected using the COSMED Q-NRG + ® calorimeter. The RQ was significantly lower in the acute SIT group (0.76 [0.01]; p < 0.0001) than in the resting group (0.80 [0.01]; p = 0.036) at the 120-min postprandial time point, and the RQ area under the curve (AUC) was also lower in the SIT group (mean difference of -6.62, 95% CI -12.00 to -1.24; p = 0.0161). The contribution of fat to energy expenditure increased after SIT during the postprandial period whereas the contribution of carbohydrates decreased. The AUC for fat contribution was significantly higher (mean difference 2311.9, 95% confidence interval [CI] 578.8 to 4043.3; p = 0.0098) and the AUC for carbohydrate contribution was significantly lower (mean difference -2283.1, 95% CI -4040.2 to -527.1; p = 0.0117) in the SIT group than in the resting group. In conclusions, acute SIT might have a positive effect on metabolic responses to postprandial glucose and, accordingly, should be recommended for improving metabolism in people with overweight/obesity.

FAT/CD36 Participation in Human Skeletal Muscle Lipid Metabolism: A Systematic Review

Fatty acid translocase/cluster of differentiation 36 (FAT/CD36) is a multifunctional membrane protein activated by a high-fat diet, physical exercise, fatty acids (FAs), leptin, and insulin. The principal function of FAT/CD36 is to facilitate the transport of long-chain fatty acids through cell membranes such as myocytes, adipocytes, heart, and liver. Under high-energy expenditure, the different isoforms of FAT/CD36 in the plasma membrane and mitochondria bind to the mobilization and oxidation of FAs. Furthermore, FAT/CD36 is released in its soluble form and becomes a marker of metabolic dysfunction. Studies with healthy animals and humans show that physical exercise and a high-lipid diet increase FAT/CD36 expression and caloric expenditure. However, several aspects such as obesity, diabetes, Single Nucleotide polymorphisms (SNPs), and oxidative stress affect the normal FAs metabolism and function of FAT/CD36, inducing metabolic disease. Through a comprehensive systematic review of primary studies, this work aimed to document molecular mechanisms related to FAT/CD36 in FAs oxidation and trafficking in skeletal muscle under basal conditions, physical exercise, and diet in healthy individuals.

Effects of high-fat diet and treadmill running on the hypothalamic Kiss-1-GPR54 signaling pathway in male growing rats

BACKGROUND

Kiss-1 neuron, one of the metabolic sensors in the hypothalamus, is necessary for puberty initiation. It acts through G protein-coupled receptor, known as GPR54. In this study, the mechanism of the hypothalamic Kiss-1-GPR54 signaling pathway in a high-fat diet and exercise was investigated in growing male rats.

METHODS

A total of 135 3-week-old male weaned rats were kept on a high-fat diet (HFD) and exercise (60-70% [Formula: see text], 1 h/day, 5 days/week). They were randomly divided, as follows: control group (C); normal diet + exercise group (CE); HFD group (H); and HFD + exercise group (HE). Hypothalamus, testis, and serum samples of each group were collected on postnatal day (PND) 21 (early childhood), 43 (puberty), and 56 (maturity). Immunofluorescence, quantitative real-time PCR, hematoxylin and eosin staining, and chemiluminescent immunoassays were used in the study. ANOVA was used to analyze the effects of age (PNDs 21, 43, and 56), exercise (exercise and sedentariness), and diet (high-fat and normal) on the biological indices of rats.

RESULTS

mRNA and protein expression of Kiss-1 and GPR54 in the hypothalamus gradually increased along with growth and peaked at PND 43, while those in serum testosterone increased and peaked at PND 56. The high-fat diet increased the expression of the Kiss-1-GPR54 system in the hypothalamus, whereas the serum testosterone decreased during different stages of growth. Exercise decreased the expression of Kiss-1 at PND 56 and increased it at PND 43. Meanwhile, it decreased testosterone and the deposition of lipid droplets in the testis at all ages of development.

CONCLUSIONS

The expression of Kiss-1-GPR54 in male rats showed fluctuating changes during growth and development. The high-fat diet was able to upregulate the expression of the Kiss-1-GPR54 system in the hypothalamus. The exercise was able to correct the adverse effect of the high-fat diet on the Kiss-1-GPR54 signaling pathway in the hypothalamus and the function of the hypothalamic-pituitary-gonadal (HPG) axis, but had age-specific effects on the male rats' development.

Intensity matters: impact of physical activity energy expenditure at moderate and vigorous intensity on total and abdominal obesity in children

BACKGROUND/OBJECTIVES

Physical activity (PA) guidelines advocate that children should accumulate at least 60 min of moderate-to-vigorous PA daily. Still, it is not clear how body fat may differ if the same dose of PA is accumulated at different intensities. We aimed to determine the independent associations of energy expenditure (EE) at moderate (MPA) and vigorous (VPA) PA intensity on total and abdominal fat in children and if these associations were moderated by cardiorespiratory fitness (CRF).

SUBJECTS/METHODS

A total of 326 children (girls = 171, boys = 151) aged 10-12 years had PA assessed with accelerometers. Total fat mass index (FMI) and abdominal FMI were assessed with DXA. CRF was assessed by a cycle ergometer test. Linear regression models were used to model the outcomes with the inclusion of an interaction term to test for moderation effects.

RESULTS

An inverse association was found between VPA EE and FMI (β = -0.013, p < 0.001) and abdominal FMI (β = -0.0014, p < 0.001) independent of MPA EE. In contrast, MPA EE was not related to adiposity independent of VPA EE (p > 0.05). The relationships between the PA intensities and FMI and abdominal FMI were moderated by CRF. MPA EE was positively associated with adiposity in children with high levels of CRF, whereas VPA EE remained inversely associated with adiposity regardless of CRF level, although the strength of the association was lower in those with higher CRF levels.

CONCLUSION

PA programs should provide opportunities for children to perform VPA in order to achieve healthier body fat profiles and avoid excess adiposity.

CD36-Fatty Acid-Mediated Metastasis via the Bidirectional Interactions of Cancer Cells and Macrophages

Tumour heterogeneity refers to the complexity of cell subpopulations coexisting within the tumour microenvironment (TME), such as proliferating tumour cells, tumour stromal cells and infiltrating immune cells. The bidirectional interactions between cancer and the surrounding microenvironment mark the tumour survival and promotion functions, which allow the cancer cells to become invasive and initiate the metastatic cascade. Importantly, these interactions have been closely associated with metabolic reprogramming, which can modulate the differentiation and functions of immune cells and thus initiate the antitumour response. The purpose of this report is to review the CD36 receptor, a prominent cell receptor in metabolic activity specifically in fatty acid (FA) uptake, for the metabolic symbiosis of cancer-macrophage. In this review, we provide an update on metabolic communication between tumour cells and macrophages, as well as how the immunometabolism indirectly orchestrates the tumour metastasis.

Eight weeks of core stability training improves landing kinetics for freestyle skiing aerials athletes

Freestyle skiing aerials are characterized by technical elements including strength, flexibility and balance. Core stability in aerials can improve sporting performance.

OBJECTIVE

This study aimed to analyze the effect of 8 weeks of core stability training on core stability performance in aerials.

METHODS

Participants were randomly assigned to a control group (CG; n = 4male + 5female; age 15.89 ± 1.54 years; height 163.11 ± 6.19 cm; weight 55.33 ± 5.07 Kg) and a training group (TG; n = 4male+5female; age 16.11 ± 2.47 years; height 161.56 ± 5.25 cm; weight 57.56 ± 8.11 Kg). Body shape, the performance of core stability, and landing kinetics were measured after 8 weeks of core stability training. Independent sample t-tests were used to compare baseline values between groups. A two-way repeated-measures analysis of variance (ANOVA) (time × group) was used.

RESULTS

The TG improved body shape, and waist circumference (t = -2.333, p = 0.020). Performance of core stability, squat (t = -4.082, p = 0.004), trunk flexion isometric test (t = -4.150, p = 0.003), trunk lateral bending isometric test (t = -2.668, p = 0.008), trunk rotation isometric test (t = -2.666, p = 0.008), side bridge (t = -2.666, p = 0.008), back hyperextension (t = -4.116, p = 0.003), single foot triple jump (t = -4.184, p = 0.003), and single-leg balance with eyes closed (t = 4.167, p = 0.003). Performance in landing kinetics, End/Phase (t = -4.015, p = 0.004), sagittal axes (t = -4.598, p = 0.002), frontal axis (t = 3.116, p = 0.014), peak power hip changing range (t = 2.666, p = 0.017), peak power knee changing range (t = 2.256, p = 0.049).

CONCLUSION

Core stability training leads to improvements in body shape, the performance of core stability, and landing kinetics. Therefore, these improvements can improve the sporting performance in aerials competitions.

A longitudinal study on associations of moderate-to-vigorous physical activity with plasma monounsaturated fatty acids in pregnancy

BACKGROUND

Physical activity (PA) during pregnancy influences women and offspring's health via fatty acids metabolism. However, studies on associations of PA with plasma monounsaturated fatty acids (MUFAs) across pregnancy are sparse. Thus, our study aimed to examine associations of PA with individual plasma phospholipid MUFAs throughout pregnancy in a prospective and longitudinal study in the United States (US).

MATERIALS AND METHODS

The study included 318 pregnant women from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singletons cohort. PA was measured four times: PA reported at 10-14 gestational weeks (GWs) representing PA in the past year, and at 15-26 GWs, 23-31 GWs, and 33-39 GWs representing PA since the last visit. Plasma phospholipid MUFAs were measured at the same four visits as the measurement of PA. Associations between moderate-to-vigorous PA (MVPA) and the total MUFAs and seven individual plasma phospholipid MUFAs (i.e., palmitoleic acid, 18:1n6-9 trans, 18:1n6c, cis-vaccenic acid, oleic acid, eicosenoic acid, and nervonic acid) were assessed at each visit using multivariable linear regression models adjusting for confounders.

RESULTS

MVPA (hours/week) reported at 15-26 GWs representing MVPA since the last visit was positively associated with total MUFAs (% of total fatty acids) [adjusted β*102 (standard error (SE)*102) = 10.41 (3.19), P = 0.001] at 15-26 GWs. For individual MUFAs, MVPA reported at 15-26 GWs representing MVPA since the last visit was positively associated with oleic acid [adjusted β*102 (SE*102) = 8.56 (2.65), P = 0.001] and eicosenoic acid [adjusted β*102 (SE*102) = 0.55 (0.20), P = 0.01] at 15-26 GWs. MVPA reported at 23-31 GWs representing MVPA since the last visit was positively associated with palmitoleic acid [adjusted β*102 (SE*102) = 2.24 (0.64), P = 0.001] at 23-31 GWs. MVPA reported at 10-14 GWs and 33-39 GWs was not associated with total or individual MUFAs.

CONCLUSION

We found novel positive associations of MVPA with individual MUFAs, such as oleic acid, eicosenoic acid, and palmitoleic acid, during middle-to-late pregnancy. These findings suggest that MVPA represents a potentially modifiable factor for plasma individual MUFA levels during pregnancy.

The emerging role of skeletal muscle as a modulator of lipid profile the role of exercise and nutrition

The present article aims to discuss the hypothesis that skeletal muscle per se but mostly its muscle fiber composition could be significant determinants of lipid metabolism and that certain exercise modalities may improve metabolic dyslipidemia by favorably affecting skeletal muscle mass, fiber composition and functionality. It discusses the mediating role of nutrition, highlights the lack of knowledge on mechanistic aspects of this relationship and proposes possible experimental directions in this field.

Physical fitness and maternal body composition indices during pregnancy and postpartum: the GESTAFIT project

We explored the association of physical fitness (PF) during pregnancy with maternal body composition indices along pregnancy and postpartum period. The study comprised 159 pregnant women (32.9 ± 4.7 years old). Assessments were carried out at the 16th and 34th gestational weeks (g.w.) and six weeks postpartum. Cardiorespiratory fitness (CRF), muscular strength (absolute and relative values) and flexibility were measured. Body composition indices were obtained by using dual-energy X-ray absorptiometry at postpartum. The results, after adjusting for potential covariates at the 16th g.w., indicated that greater CRF was associated with lower postpartum indices total fat mass, android and gynoid fat mass (all, p < 0.05). Greater absolute upper-body muscular strength was associated with greater pre-pregnancy body mass index (BMI), gestational weight gain (GWG); and postpartum indices body weight, BMI, lean mass, fat free mass, fat mass, gynoid fat mass, T-score and Z-score bone mineral density (BMD) (all, p < 0.05). Greater upper-body flexibility was associated with lower pre-pregnancy BMI; and postpartum indices body weight, BMI, lean mass, fat free mass, fat mass, android fat mass and gynoid fat mass, and with greater GWG (all, p < 0.05). At the 34th g.w., greater CRF was additionally associated with greater postpartum T-score and Z-score BMD (both, p < 0.05). In conclusion, this study reveals that greater PF levels, especially during early pregnancy, may promote a better body composition in the postpartum period. Therefore, clinicians and health promoters should encourage women to maintain or improve PF levels from early pregnancy.

Acculturation, Physical Activity, and Metabolic Syndrome in Asian American Adults

INTRODUCTION

Asian Americans (AsAms) have a high prevalence of metabolic syndrome (MetS) and are one of the least physically active racial groups in America. The purpose of this study was to examine the relationship between MetS and moderate-to-vigorous physical activity (MVPA) among AsAm adults and whether acculturation modifies this relationship.

METHOD

Data were from 2,259 AsAms participating in the 2011-2016 National Health and Nutrition Examination Survey. Physical activity (PA) was self-reported as minutes of weekly MVPA. Acculturation included nativity, length of residency in America, and language preference. The International Diabetes Federation criteria was used to determine the presence of MetS.

RESULTS

About 64.4% of AsAms did not meet the PA recommendation (MVPA ≥150 min/week). The prevalence of MetS was 39.2%. The odds of having MetS were greater among AsAms who did not meet MVPA recommendations compared with those who did meet MVPA recommendations (odds ratio [OR] = 1.5, 95% confidence interval [CI] = [1.11, 2.07]). When stratified by acculturation, this association remained statistically significant in the groups who immigrated to America more than 15 years ago and who spoke English only.

CONCLUSION

MVPA reduces MetS risk in AsAm adults, especially among more acculturated AsAms. Culturally adapted programs are warranted to promote PA and adequate knowledge of disease prevention in this population.

Associations of clinical and circulating metabolic biomarkers with low physical fitness and function in adults with chronic lymphocytic leukemia

Many patients with chronic lymphocytic leukemia (CLL) experience physical dysfunction and low overall fitness. It remains unknown what factors drive CLL physical dysfunction. We assessed physical function and metabolic lipoprotein panels in 106 patients with CLL. In univariate analyses of clinical factors, a longer time since diagnosis was associated with a higher likelihood of dysfunctional aerobic fitness (OR = 3.56, 95% CI: 1.37–9.22; p = 0.002) and physical performance (SPPB: OR = 2.03, 95% CI: 1.20–3.44; p = 0.004). Having received treatment was associated with a higher likelihood of dysfunctional aerobic fitness (OR = 1.57, 95% CI: 1.02–2.40; p = 0.036), SPPB (OR = 1.85, 95% CI: 1.13–3.03; p = 0.011) and grip strength (OR = 1.67, 95% CI: 1.10–2.55; p = 0.015). We found that several small HDL particle parameters, higher levels of citrate (OR = 2.01, 95% CI: 1.22–3.31; p = 0.030), and lower levels of hemoglobin (OR = 0.50, 95% CI: 0.31–0.82; p = 0.030) were associated with a higher likelihood of dysfunctional aerobic fitness. Multivariable least absolute shrinkage and selection operator (LASSO)-penalized regression analyses using variable importance measures (VIM) showed that 7.8-nm HDL particles (VIM = 1.000) and total HDL particle levels (VIM = 1.000) were more informative than clinical measures for the odds of dysfunctional aerobic fitness and 6-min walk functional fitness, respectively, while 10.3-nm HDL particles (VIM = 0.383) were more informative for grip strength. Time since diagnosis (VIM = 0.680) and having received treatment (VIM = 0.490) were more informative than lipoprotein measures for the odds of having dysfunctional SPPB. Taken together, we establish significant relationships between clinical and metabolic factors and physical characteristics that might prompt early use of ancillary support services.

Effect of Sports Energy Drink on Fat Metabolism and Weight Loss of College Students

In order to solve the problem of fat metabolism and weight loss of college students, this paper puts forward a problem of the influence of sports energy drinks. Energy drink is a combination of sports drinks, energy drinks, and other special functional drinks (such as nutrient drinks with added vitamins and minerals; herbal drinks with Chinese herbal ingredients), a general term for a large category of drinks that provide specific health and nutritional functions for special groups of people. With the continuous improvement of people's consumption level and their constant attention to their own health, the consumption of energy drinks is also increasing. Energy drinks have become a new generation of drinks after carbonated drinks, drinking water, fruit and vegetable juice, and tea. At present, the total annual output of beverages in the world exceeds 300 billion liters, and functional beverages have become the fastest growing beverage varieties. Fat is the main energy supply material for endurance sports. The catabolism of fat during sports is the key link for the body to obtain energy. For the general population, abnormal fat metabolism is the main cause of obesity. In this paper, 10 healthy male and female college students without training experience were used to determine the maximum fat metabolism intensity FATmax. Based on this, the exercise prescription of maximum fat oxidation intensity for 8 weeks was formulated. The functional ability, maximum oxygen uptake, body fat percentage, quiet heart rate, blood pressure, and vital capacity before and after the experiment were measured to observe the exercise effect. The fitness effect of maximum fat metabolism intensity was studied to provide theoretical support for college students’ fitness exercise. The study found that there was no significant difference between boys and girls in the maximum fat oxidation rate and FATmax, and girls’ E. C. and running speed corresponding to FATmax were significantly lower than those of boys. After 8 weeks of exercise prescription exercise of maximum fat metabolism intensity, the E. C. and maximum oxygen uptake of boys and girls increased significantly; quiet heart rate, vital capacity index, and body fat percentage were significantly improved; and the changes in girls were more significant than boys. The results show that there is no gender difference in FATmax. The corresponding exercise intensity (7.22 METs for boys and 5.25 METs for girls) and running speed (9.73 km/h for boys and 8.65 km/h for girls) can be used as a reference for formulating college students’ fitness exercise prescriptions. The fitness exercise prescription based on FATmax can improve cardiopulmonary function and body composition, especially for girls. FATmax can be used as a reference standard for formulating fitness exercise prescriptions.

Comparison of visceral fat lipolysis adaptation to high-intensity interval training in obesity-prone and obesity-resistant rats

BACKGROUND/OBJECTIVES

Visceral obesity is one of the key features of metabolic syndrome. High-intensity interval training (HIIT) could effectively reduce visceral fat, but its effects show strong heterogeneity in populations with different degrees of obesity. The mechanism may be related to the differential adaptation to training between obesity phenotypes, namely obesity prone (OP) and obesity resistant (OR). The aim of the present study was to compare adaptive changes of visceral adipose lipolysis adaptation to HIIT between OP and OR animals and further explore the upstream pathway.

METHODS

OP and OR Sprague Dawley rats were established after feeding a high-fat diet for 6 weeks; they were then divided into HIIT (H-OP and H-OR) and control (C-OP and C-OR) groups. After 12 weeks of HIIT or a sedentary lifestyle, animals were fasted for 12 h and then sacrificed for histology as well as gene and protein analysis. Visceral adipocytes were isolated without fasting for catecholamine stimulation and β3-adrenergic receptor (β3-AR) blockade in vitro to evaluate the role of upstream pathways.

RESULTS

After training, there were no differences in weight loss or food intake between OP and OR rats (P > 0.05). However, the visceral fat mass, adipocyte volume, serum triglycerides and liver lipids of OP rats decreased by more than those of OR rats (P < 0.05). Meanwhile, the cell lipolytic capacity and the increase in the expression of β3-AR were higher in the OP compared with OR groups (P < 0.05). Although training did not increase sympathetic nervous system activity (P > 0.05), the cell sensitivity to catecholamine increased significantly in the OP compared with OR groups (P < 0.05). Following blocking β3-AR, the increased sensitivity disappeared.

CONCLUSION

With HIIT, OP rats lost more visceral fat than OR rats, which was related to stronger adaptive changes in lipolysis. Increased β3-AR expression mediated this adaptation.

Biomarkers and genetic polymorphisms associated with maximal fat oxidation during physical exercise: implications for metabolic health and sports performance

The maximal fat oxidation rate (MFO) assessed during a graded exercise test is a remarkable physiological indicator associated with metabolic flexibility, body weight loss and endurance performance. The present review considers existing biomarkers related to MFO, highlighting the validity of maximal oxygen uptake and free fatty acid availability for predicting MFO in athletes and healthy individuals. Moreover, we emphasize the role of different key enzymes and structural proteins that regulate adipose tissue lipolysis (i.e., triacylglycerol lipase, hormone sensitive lipase, perilipin 1), fatty acid trafficking (i.e., fatty acid translocase cluster of differentiation 36) and skeletal muscle oxidative capacity (i.e., citrate synthase and mitochondrial respiratory chain complexes II-V) on MFO variation. Likewise, we discuss the association of MFO with different polymorphism on the ACE, ADRB3, AR and CD36 genes, identifying prospective studies that will help to elucidate the mechanisms behind such associations. In addition, we highlight existing evidence that contradict the paradigm of a higher MFO in women due to ovarian hormones activity and highlight current gaps regarding endocrine function and MFO relationship.

Novel Insights into the Differences in Nutrition Value, Gene Regulation and Network Organization between Muscles from Pasture-Fed and Barn-Fed Goats

The physiological and biochemical characters of muscles derived from pasture-fed or barn-fed black goats were detected, and RNA-seq was performed to reveal the underlying molecular mechanisms to identify how the pasture feeding affected the nutrition and flavor of the meat. We found that the branched chain amino acids, unsaturated fatty acids, and zinc in the muscle of pasture-fed goats were significantly higher than those in the barn-fed group, while the heavy metal elements, cholesterol, and low-density lipoprotein cholesterol were significantly lower. RNA-seq results showed that 1761 genes and 147 lncRNA transcripts were significantly differentially expressed between the pasture-fed and barn-fed group. Further analysis found that the differentially expressed genes were mainly enriched in the myogenesis and Glycerophospholipid metabolism pathway. A functional analysis of the lncRNA transcripts further highlighted the difference in fatty acid metabolism between the two feeding models. Our study provides novel insights into the gene regulation and network organization of muscles and could be potentially used for improving the quality of mutton.

The Effect of Long-Lasting Swimming on Rats Skeletal Muscles Energy Metabolism after Nine Days of Dexamethasone Treatment

This study investigates the effect of Dexamethasone (Dex) treatment on blood and skeletal muscle metabolites level and skeletal muscle activity of enzymes related to energy metabolism after long-duration swimming. To evaluate whether Dex treatment, swimming, and combining these factors act on analyzed data, rats were randomly divided into four groups: saline treatment non-exercise and exercise and Dex treatment non-exercised and exercised. Animals in both exercised groups underwent long-lasting swimming. The concentration of lipids metabolites, glucose, and lactate were measured in skeletal muscles and blood according to standard colorimetric and fluorimetric methods. Also, activities of enzymes related to aerobic and anaerobic metabolism were measured in skeletal muscles. The results indicated that Dex treatment induced body mass loss and increased lipid metabolites in the rats’ blood but did not alter these changes in skeletal muscles. Interestingly, prolonged swimming applied after 9 days of Dex treatment significantly intensified changes induced by Dex; however, there was no difference in skeletal muscle enzymatic activities. This study shows for the first time the cumulative effect of exercise and Dex on selected elements of lipid metabolism, which seems to be essential for the patient’s health due to the common use of glucocorticoids like Dex.

Sex differences in white adipose tissue expansion: emerging molecular mechanisms

The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.

Anthropometric, biochemical and clinical parameters in climacteric yoga practitioners

OBJECTIVE

This study aimed to evaluate anthropometric, biochemical and clinical parameters in climacteric yoga practitioners.

METHODS

This study investigated 108 climacteric women. We recruited 28 women between 40 and 65 years old who started yoga practices in premenopause and had already practiced for at least 5 years. As controls, we selected 30 physical activity (PA) practitioners who had practiced for at least 5 years and 50 sedentary women in the same age range. We conduced anthropometric, biochemical and blood pressure measurements.

RESULTS

The yoga group had significantly lower fasting blood glucose than the PA practitioners and sedentary women. Yoga practitioners also had lower weight, body mass index, waist circumference, body fat percentage and waist-to-height ratio; higher levels of high-density lipoprotein cholesterol; lower levels of triglycerides, insulin, Homeostasis Model Assessment of Insulin Resistance, uric acid, apolipoprotein B and high-sensitivity C-reactive protein; and lower frequency of metabolic syndrome, lipid accumulation product, visceral adiposity index and systolic blood pressure than the sedentary women.

CONCLUSION

Yoga practitioners had lower glucose serum concentrations than the PA practitioners and sedentary women. Overall, the yoga group also had better anthropometric, biochemical and clinical variables than the other groups. Although further investigation is required, yoga practice in premenopause seems to be beneficial for women when they reach menopause.

Treadmill Running Changes Endothelial Lipase Expression: Insights from Gene and Protein Analysis in Various Striated Muscle Tissues and Serum

Endothelial lipase (EL) is an enzyme capable of HDL phospholipids hydrolysis. Its action leads to a reduction in the serum high-density lipoprotein concentration, and thus, it exerts a pro-atherogenic effect. This study examines the impact of a single bout exercise on the gene and protein expression of the EL in skeletal muscles composed of different fiber types (the soleus—mainly type I, the red gastrocnemius—mostly IIA, and the white gastrocnemius—predominantly IIX fibers), as well as the diaphragm, and the heart. Wistar rats were subjected to a treadmill run: (1) t = 30 [min], V = 18 [m/min]; (2) t = 30 [min], V = 28 [m/min]; (3) t = 120 [min], V = 18 [m/min] (designated: M30, F30, and M120, respectively). We established EL expression in the total muscle homogenates in sedentary animals. Resting values could be ordered with the decreasing EL protein expression as follows: endothelium of left ventricle > diaphragm > red gastrocnemius > right ventricle > soleus > white gastrocnemius. Furthermore, we observed that even a single bout of exercise was capable of inducing changes in the mRNA and protein level of EL, with a clearer pattern observed for the former. After 30 min of running at either exercise intensity, the expression of EL transcript in all the cardiovascular components of muscles tested, except the soleus, was reduced in comparison to the respective sedentary control. The protein content of EL varied with the intensity and/or duration of the run in the studied whole tissue homogenates. The observed differences between EL expression in vascular beds of muscles may indicate the muscle-specific role of the lipase.