Glucose Uptake by Skeletal Muscle within the Contexts of Type 2 Diabetes and Exercise: An Integrated Approach

MASLD/MASH and type 2 diabetes: Two sides of the same coin? From single PPAR to pan-PPAR agonists

Type 2 diabetes (T2D) and metabolic dysfunction-associated steatotic liver disease (MASLD), mainly related to nutrition and lack of physical activity, are both very common conditions, share several disease pathways and clinical manifestations, and increasingly co-occur with disease progression. Insulin resistance is an upstream node in the biology of both conditions and triggers liver parenchymal injury, inflammation and fibrosis. Peroxisome proliferator-activated receptor (PPAR) nuclear transcription factors are master regulators of energy homeostasis - insulin signaling in liver, adipose and skeletal muscle tissue - and affect immune and fibrogenesis pathways. Among distinct yet overlapping effects, PPARα regulates lipid metabolism and energy expenditure, PPARβ/δ has anti-inflammatory effects and increases glucose uptake by skeletal muscle, while PPARγ improves insulin sensitivity and exerts direct antifibrotic effects on hepatic stellate cells. Together PPARs thus represent pharmacological targets across the entire biology of MASH. Single PPAR agonists are approved for hypertriglyceridemia (PPARα) and T2D (PPARγ), but these, as well as dual PPAR agonists, have shown mixed results as anti-MASH treatments in clinical trials. Agonists of all three PPAR isoforms have the potential to improve the full disease spectrum from insulin resistance to fibrosis, and correspondingly to improve cardiometabolic and hepatic health, as has been shown (phase II data) with the pan-PPAR agonist lanifibranor.

Stem cell secretome treatment improves whole-body metabolism, reduces adiposity, and promotes skeletal muscle function in aged mice

Aging coincides with the progressive loss of muscle mass and strength, increased adiposity, and diminished physical function. Accordingly, interventions aimed at improving muscle, metabolic, and/or physical health are of interest to mitigate the adverse effects of aging. In this study, we tested a stem cell secretome product, which contains extracellular vesicles and growth, cytoskeletal remodeling, and immunomodulatory factors. We examined the effects of 4 weeks of 2×/week unilateral intramuscular secretome injections (quadriceps) in ambulatory aged male C57BL/6 mice (22-24 months) compared to saline-injected aged-matched controls. Secretome delivery substantially increased whole-body lean mass and decreased fat mass, corresponding to higher myofiber cross-sectional area and smaller adipocyte size, respectively. Secretome-treated mice also had greater whole-body physical function (grip strength and rotarod performance) and had higher energy expenditure and physical activity levels compared to control mice. Furthermore, secretome-treated mice had greater skeletal muscle Pax7+ cell abundance, capillary density, collagen IV turnover, reduced intramuscular lipids, and greater Akt and hormone sensitive lipase phosphorylation in adipose tissue. Finally, secretome treatment in vitro directly enhanced muscle cell growth and IL-6 production, and in adipocytes, it reduced lipid content and improved insulin sensitivity. Moreover, indirect treatment with secretome-treated myotube culture media also enhanced muscle cell growth and adipocyte size reduction. Together, these data suggest that intramuscular treatment with a stem cell secretome improves whole-body metabolism, physical function, and remodels skeletal muscle and adipose tissue in aged mice.

Biotechnological potential of actinomycetes in the 21st century: a brief review

This brief review aims to draw attention to the biotechnological potential of actinomycetes. Their main uses as sources of antibiotics and in agriculture would be enough not to neglect them; however, as we will see, their biotechnological application is much broader. Far from intending to exhaust this issue, we present a short survey of the research involving actinomycetes and their applications published in the last 23 years. We highlight a perspective for the discovery of new active ingredients or new applications for the known metabolites of these microorganisms that, for approximately 80 years, since the discovery of streptomycin, have been the main source of antibiotics. Based on the collected data, we organize the text to show how the cosmopolitanism of actinomycetes and the evolutionary biotic and abiotic ecological relationships of actinomycetes translate into the expression of metabolites in the environment and the richness of biosynthetic gene clusters, many of which remain silenced in traditional laboratory cultures. We also present the main strategies used in the twenty-first century to promote the expression of these silenced genes and obtain new secondary metabolites from known or new strains. Many of these metabolites have biological activities relevant to medicine, agriculture, and biotechnology industries, including candidates for new drugs or drug models against infectious and non-infectious diseases. Below, we present significant examples of the antimicrobial spectrum of actinomycetes, which is the most commonly investigated and best known, as well as their non-antimicrobial spectrum, which is becoming better known and increasingly explored.

Using propensity score matching analysis to compare between cardiometabolic risk factors and physical activity type in Korean adults: findings from a nationwide population-based survey

PURPOSE

We aimed to assess the effects of different exercise modalities on cardiometabolic risk factors within a comprehensive, representative sample of the Korean population.

METHODS

We categorized 13,971 adult participants into aerobic exercise (AE), resistance exercise (RE), combined aerobic and resistance exercise (TE), insufficient exercise, and inactive groups. Multivariable regressions were conducted to compare the incidence of chronic diseases across the groups before and after propensity score matching (PSM).

RESULTS

The TE and RE groups had significantly lower waist circumference (WC), mean blood pressure (BP), glucose and insulin-related indices, and white blood cell count (WBC) measures, with TE showing the most significant differences. The TE group had significantly lower triglyceride levels and higher high-density lipoprotein-cholesterol levels. Post-PSM, the TE group had the lowest risk for metabolic syndrome, hypertension, and diabetes, closely followed by the RE group when compared with the inactive group. In a subgroup analysis, RE consistently exhibited benefits including lower body mass index, WC, BP, total cholesterol, glucose and insulin-related indices, and WBC count when compared with AE. RE may be associated with reduced incidence of cardiometabolic diseases compared to AE alone.

CONCLUSION

TE appears to be associated with significant reduction in cardiometabolic risk in Korean adults. RE possibly provides a more favorable cardiometabolic effect than AE.

Prevalence and Associated Factors of Sensorineural Hearing Impairment Among Patients with T2DM in Amhara Region, Northwest Ethiopia, 2022: A Multi-Centered Cross-Sectional Study

Background

Generally, people with type 2 diabetes mellitus in various countries experience a significant rate of sensorineural hearing impairment. Nonetheless, there is scant evidence of sensorineural hearing impairment among type 2 diabetes mellitus patients in Northwest Ethiopian. Therefore, the objective of this study was to evaluate the occurrence rate and contributing factors of sensorineural hearing impairment in type 2 diabetics at comprehensive and specialized referral hospitals in Northwest Ethiopia.

Methods

A facility-based cross-sectional study design was carried out from May 3, 2022, to June 14, 2022, on 846 study participants in Ethiopia, with a response rate of 99.65%. The research subjects were chosen by simple random sampling techniques. Data was gathered by using audiometric measurements and structured interview-administered questionnaires and then entered into EPI data version 4.6. Finally, it was exported to STATA 14 for analysis. Binary logistic regression, chi-square test, and odds ratio were done to verify the assumptions and degree of association. Ultimately, factors exhibiting a p-value < 0.05 with a 95% CI were regarded as significant predictors of hearing impairment.

Results

The magnitude of sensorineural hearing impairment in this investigation was 50.49% (95% CI: 45.67%, 55.26%). Factors significantly associated with sensorineural hearing impairment were age (AOR=1.10, 95% CI: 1.07, 1.14), hyperlipidemia (AOR=2.86, 95% CI: 1.05, 7.82), duration of diabetes (AOR=2.26, 95% CI: 1.26, 4.06), hypertension (AOR=1.94, 95% CI: 1.02, 3.69) and regular physical exercise (AOR=0.25, 95% CI: 0.09, 0.68).

Conclusions and Recommendations

In this study, relatively high rates of sensorineural hearing impairment were observed. Stakeholders should establish routine hearing screening, and participants will advise to incorporate regular physical exercise into their routines.

The Lipophilic Extract from Ginkgo biloba L. Leaves Promotes Glucose Uptake and Alleviates Palmitate-Induced Insulin Resistance in C2C12 Myotubes

Ginkgo biloba L. (ginkgo) is a widely used medicinal plant around the world. Its leaves, which have been used as a traditional Chinese medicine, are rich in various bioactive components. However, most of the research and applications of ginkgo leaves have focused on terpene trilactones and flavonol glycosides, thereby overlooking the other active components. In this study, a lipophilic extract (GL) was isolated from ginkgo leaves. This extract is abundant in lipids and lipid-like molecules. Then, its effect and potential mechanism on glucose uptake and insulin resistance in C2C12 myotubes were investigated. The results showed that GL significantly enhanced the translocation of GLUT4 to the plasma membrane, which subsequently promoted glucose uptake. Meanwhile, it increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream targets. Both knockdown of AMPK with siRNA and inhibition with AMPK inhibitor compound C reversed these effects. Additionally, GL ameliorated palmitate-induced insulin resistance by enhancing insulin-stimulated glucose uptake, increasing the phosphorylation of protein kinase B (PKB/AKT), and restoring the translocation of GLUT4 from the cytoplasm to the membrane. However, pretreatment with compound C abolished these beneficial effects of GL. In conclusion, GL enhances basal glucose uptake in C2C12 myotubes and improves insulin sensitivity in palmitate-induced insulin resistant myotubes through the AMPK pathway.

Exploring the Causal Relationship Between Modifiable Exposures and Diabetes Mellitus: A Two-Sample Mendelian Randomization Analysis

Background Observational studies link lifestyle factors to diabetes, but confounding limits causal inference. This study employed Mendelian randomization (MR) to investigate the potential causal effects of major dietary, obesity, smoking, and physical activity exposures on diabetes risk. Methods A two-sample MR framework integrated FinnGen and United Kingdom Biobank (UKB) data. Genetic instruments for diet (fruits, vegetables, cheese), smoking (initiation, intensity, maternal), body mass index (BMI), and physical activity came from various consortia (n=64, 949-632, 802). Associations with diabetes odds were assessed using inverse-variance weighted analysis. Results Fruit and cheese intake and physical activity per standard deviation increase causally reduced diabetes risk in both cohorts. Conversely, smoking initiation, maternal smoking around birth, and BMI per standard deviation increase causally increased diabetes risk in both cohorts. Coffee increased diabetes risk only in FinnGen, whereas smoking intensity increased diabetes risk only in UKB. Conclusion This study provides robust evidence that modifiable lifestyle factors may have causal effects on diabetes risk. Fruit, cheese, and physical activity may protect against diabetes, whereas smoking, maternal smoking, and higher BMI appear to increase risk. Findings support public health interventions targeting diet, physical activity, smoking cessation, and healthy weight to combat the global diabetes epidemic.

The cardiovascular changes underlying a low cardiac output with exercise in patients with type 2 diabetes mellitus

The significant morbidity and premature mortality of type 2 diabetes mellitus (T2DM) is largely associated with its cardiovascular consequences. Focus has long been on the arterial atheromatosis of DM giving rise to early stroke and myocardial infarctions, whereas less attention has been given to its non-ischemic cardiovascular consequences. Irrespective of ischemic changes, T2DM is associated with heart failure (HF) most commonly with preserved ejection fraction (HFpEF). Largely due to increasing population ages, hypertension, obesity and T2DM, HFpEF is becoming the most prevalent form of heart failure. Unfortunately, randomized controlled trials of HFpEF have largely been futile, and it now seems logical to address the important different phenotypes of HFpEF to understand their underlying pathophysiology. In the early phases, HFpEF is associated with a significantly impaired ability to increase cardiac output with exercise. The lowered cardiac output with exercise results from both cardiac and peripheral causes. T2DM is associated with left ventricular (LV) diastolic dysfunction based on LV hypertrophy with myocardial disperse fibrosis and significantly impaired ability for myocardial blood flow increments with exercise. T2DM is also associated with impaired ability for skeletal muscle vasodilation during exercise, and as is the case in the myocardium, such changes may be related to vascular rarefaction. The present review discusses the underlying phenotypical changes of the heart and peripheral vascular system and their importance for an adequate increase in cardiac output. Since many of the described cardiovascular changes with T2DM must be considered difficult to change if fully developed, it is suggested that patients with T2DM are early evaluated with respect to their cardiovascular compromise.

Coconut (Cocos nucifera (L.)) Water Improves Glucose Uptake with Concomitant Modulation of Antioxidant and Purinergic Activities in Isolated Rat Psoas Muscles

The present study investigated the effect of coconut water on glucose uptake and utilization, and metabolic activities linked to hyperglycemia in isolated rat psoas muscles. Coconut water was subjected to in vitro antioxidant and antidiabetic assays, which cover 2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing antioxidant power (FRAP), and inhibition of α-glucosidase and α-amylase activities. Psoas muscles were isolated from male Sprague Dawley rats and incubated with coconut water in the presence of glucose. Control consisted of muscles incubated with glucose only, while normal control consisted of muscles not incubated in coconut water and/or glucose. The standard antidiabetic drug was metformin. Incubation with coconut water led to a significant increase in muscle glucose uptake, with concomitant exacerbation of glutathione level, and SOD and catalase activities, while suppressing malondialdehyde level, and ATPase and E-NTDase activities. Coconut water showed significant scavenging activity against DPPH, and significantly inhibited α-glucosidase and α-amylase activities. LC-MS analysis of coconut water revealed the presence of ellagic acid, butin, quercetin, protocatechuic acid, baicalin, and silibinin. Molecular docking analysis revealed potent molecular interactions between the LC-MS-identified compounds, and AKT-2 serine and PI-3 kinase. These results indicate the potential of coconut water to enhance glucose uptake, while concomitantly improving antioxidative and purinergic activities. They also indicate the potential of coconut water to suppress postprandial hyperglycemia. These activities may be attributed to the synergistic effects of the LC-MS-identified compounds.

Nicotinamide Mononucleotide (NMN) Works in Type 2 Diabetes through Unexpected Effects in Adipose Tissue, Not by Mitochondrial Biogenesis

Nicotinamide mononucleotide (NMN) has emerged as a promising therapeutic intervention for age-related disorders, including type 2 diabetes. In this study, we confirmed the previously observed effects of NMN treatment on glucose uptake and investigated its underlying mechanisms in various tissues and cell lines. Through the most comprehensive proteomic analysis to date, we discovered a series of novel organ-specific effects responsible for glucose uptake as measured by the IPGTT: adipose tissue growing (suggested by increased protein synthesis and degradation and mTOR proliferation signaling upregulation). Notably, we observed the upregulation of thermogenic UCP1, promoting enhanced glucose conversion to heat in intermuscular adipose tissue while showing a surprising repressive effect on mitochondrial biogenesis in muscle and the brain. Additionally, liver and muscle cells displayed a unique response, characterized by spliceosome downregulation and concurrent upregulation of chaperones, proteasomes, and ribosomes, leading to mildly impaired and energy-inefficient protein synthesis machinery. Furthermore, our findings revealed remarkable metabolic rewiring in the brain. This involved increased production of ketone bodies, downregulation of mitochondrial OXPHOS and TCA cycle components, as well as the induction of well-known fasting-associated effects. Collectively, our data elucidate the multifaceted nature of NMN action, highlighting its organ-specific effects and their role in improving glucose uptake. These findings deepen our understanding of NMN's therapeutic potential and pave the way for novel strategies in managing metabolic disorders.

Glucosamine substituted sulfonylureas: IRS-PI3K-PKC-AKT-GLUT4 insulin signalling pathway intriguing agent

Normally, skeletal muscle accounts for 70-80% of insulin-stimulated glucose uptake in the postprandial hyperglycemia state. Consequently, abnormalities in glucose uptake by skeletal muscle or insulin resistance (IR) are deemed as initial metabolic defects in the pathogenesis of type 2 diabetes mellitus (T2DM). Globally, T2DM is growing in exponential proportion. The majority of T2DM patients are treated with sulfonylureas in combination with other drugs to improve insulin sensitivity. Glycosylated sulfonylureas (sulfonylurea-glucosamine analogues) are modified analogues of sulfonylurea that have been previously reported to possess antidiabetic activity. The aim of this study was to evaluate the impact of glycosylated sulfonylureas on the insulin signalling pathway at the molecular level using L6 skeletal muscle cell (in vitro) and extracted soleus muscle (ex vivo) models. To create an in vitro model, insulin resistance was established utilizing a high insulin-glucose approach in differentiated L6 muscle cells from Rattus norvegicus. Additionally, for the ex vivo model, extracted soleus muscles, adult Sprague-Dawley rats were subjected to a solution containing 25 mmol L-1 glucose and 100 mmol L-1 insulin for 24 hours to induce insulin resistance. After insulin resistance, compounds under investigation and standard medicines (metformin and glimepiride) were tested. The differential expression of PI3K, IRS-1, PKC, AKT2, and GLUT4 genes involved in the insulin signaling pathway was evaluated using qPCR. The evaluated glycosylated sulfonylurea analogues exhibited a significant increase in the gene expression of insulin-dependent pathways both in vitro and ex vivo, confirming the rejuvenation of the impaired insulin signaling pathway genes. Altogether, glycosylated sulfonylurea analogues described in this study represent potential therapeutic anti-diabetic drugs.

Application of conventional ultrasound coupled with shear wave elastography in the assessment of muscle strength in patients with type 2 diabetes

Background

In patients with type 2 diabetes mellitus (T2DM), a decrease in muscle function may be related to changes in the biomechanical properties of skeletal muscles. However, the correlations between muscle function and the characteristics of muscle size and stiffness as measured by ultrasound in patients with T2DM are unclear. The aim of this study was to investigate the abilities of conventional ultrasound and shear wave elastography (SWE) to assess muscle properties in patients with T2DM and to correlate the findings with isokinetic muscle testing and functional tests.

Methods

Sixty patients from the Department of Endocrinology in The Third Affiliated Hospital of Southern Medical University diagnosed with T2DM were recruited in this cross-sectional study from September 2021 to September 2022. T2DM was defined based on the American Diabetes Association criteria. The exclusion criteria were a history of injury or operation of the lower limb or clinical signs of neuromuscular disorders, any muscle-induced disease, and the presence of other types of diabetes mellitus. Thirty-five matched healthy volunteers were continuously included in the control group. SWE was used to measure the muscle stiffness of the quadriceps femoris [vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), vastus intermedius (VI)] and the biceps brachii (BB) in a relaxed position, and the shear wave velocity (SWV) values were recorded. Muscle size was measured using conventional ultrasound. The participants underwent isokinetic knee extension/flexion (60°/sec) to assess muscle strength and functional tests of physical performance, including the short physical performance battery, 30-s chair stand test, timed up-and-go test, and 6-meter walk test. All demographics and measured variables were compared using the independent samples t-test. Interclass correlation coefficient analysis was performed on the measurement data obtained by the two operators, and Pearson correlation coefficients were used to determine the relationships between variables.

Results

Patients with T2DM exhibited worse physical performance (P<0.05) and weaker lower limb muscle strength (P<0.05) than did healthy controls, but their handgrip strength was comparable (P=0.102). Patients with T2DM had significantly decreased muscle thickness [RF thickness: 10.69±3.21 vs. 13.09±2.41 mm, mean difference =-2.40, 95% confidence interval (CI): -3.56 to -1.24, P<0.001; anterior quadriceps thickness: 23.45±7.11 vs. 27.25±5.25 mm, mean difference =-3.80, 95% CI: -6.33 to -1.26, P=0.004] and RF cross-sectional area (3.04±1.10 vs. 4.11±0.95 cm2, mean difference =-1.07, 95% CI: -1.49 to -0.64; P<0.001) compared to healthy controls. Smaller muscle size was associated with decreased muscle strength (r=0.44-0.69, all P values <0.001). Except for the BB (3.48±0.38 vs. 3.61±0.61 m/s, mean difference =-0.12, 95% CI: -0.35 to 0.11; P=0.257) and VI (2.59±0.34 vs. 2.52±0.23 m/s, mean difference =0.03, 95% CI: -0.06 to 0.18; P=0.299), the muscle stiffness in patients with T2DM was significantly decreased. For the patients with T2DM and healthy participants, the SWV of the RF was 1.66±0.23 and 1.83±0.18 m/s (mean difference =-0.17, 95% CI: -0.25 to -0.08; P<0.001), respectively; that of the VM was 1.34±0.15 and 1.51±0.16 m/s (mean difference =-0.17, 95% CI: -0.24 to -0.10; P<0.001), respectively; and that of VL was 1.38±0.19 and 1.53±0.19 m/s (mean difference =-0.15, 95% CI: -0.23 to -0.07; P<0.001), respectively. Excellent interobserver reliability of the SWV measurements on the muscle of T2DM patients was observed (all intraclass correlation coefficients >0.75; P<0.001). The SWV showed moderate correlations with muscle strength in the RF, VM, and VL (r=0.30-0.61; all P values <0.05).

Conclusions

Ultrasound technology exhibits good reliability for repeated measurements of muscle size and stiffness. Reduced muscle stiffness as detected by SWE was demonstrated in patients with diabetes and was associated with decreased muscle strength and impaired functional activity.

Sarcopenia and Diabetes: A Detrimental Liaison of Advancing Age

Sarcopenia is an age-related clinical complaint characterized by the progressive deterioration of skeletal muscle mass and strength over time. Type 2 diabetes (T2D) is associated with faster and more relevant skeletal muscle impairment. Both conditions influence each other, leading to negative consequences on glycemic control, cardiovascular risk, general health status, risk of falls, frailty, overall quality of life, and mortality. PubMed/Medline, Scopus, Web of Science, and Google Scholar were searched for research articles, scientific reports, observational studies, clinical trials, narrative and systematic reviews, and meta-analyses to review the evidence on the pathophysiology of di-abetes-induced sarcopenia, its relevance in terms of glucose control and diabetes-related outcomes, and diagnostic and therapeutic challenges. The review comprehensively addresses key elements for the clinical definition and diagnostic criteria of sarcopenia, the pathophysiological correlation be-tween T2D, sarcopenia, and related outcomes, a critical review of the role of antihyperglycemic treatment on skeletal muscle health, and perspectives on the role of specific treatment targeting myokine signaling pathways involved in glucose control and the regulation of skeletal muscle metabolism and trophism. Prompt diagnosis and adequate management, including lifestyle inter-vention, health diet programs, micronutrient supplementation, physical exercise, and pharmaco-logical treatment, are needed to prevent or delay skeletal muscle deterioration in T2D.

Resting phase-administration of lemborexant ameliorates sleep and glucose tolerance in type 2 diabetic mice

Sleep disorders are associated with increased risk of obesity and type 2 diabetes. Lemborexant, a dual orexin receptor antagonist (DORA), is clinically used to treat insomnia. However, the influence of lemborexant on sleep and glucose metabolism in type 2 diabetic state has remained unknown. In the present study, we investigated the effect of lemborexant in type 2 diabetic db/db mice exhibiting both sleep disruption and glucose intolerance. Single administration of lemborexant at the beginning of the light phase (i.e., resting phase) acutely increased total time spent in non-rapid eye movement (NREM) and REM sleep in db/db mice. Durations of NREM sleep-, REM sleep-, and wake-episodes were also increased by this administration. Daily resting-phase administration of lemborexant for 3-6 weeks improved glucose tolerance without changing body weight and glucose-stimulated insulin secretion in db/db mice. Similar improvement of glucose tolerance was caused by daily resting-phase administration of lemborexant in obese C57BL/6J mice fed high fat diet, whereas no such effect was observed in non-diabetic db/m+ mice. Diabetic db/db mice treated daily with lemborexant exhibited increased locomotor activity in the dark phase (i.e., awake phase), although they did not show any behavioral abnormality in the Y-maze, elevated plus maze, and forced swim tests. These results suggest that timely promotion of sleep by lemborexant improved the quality of wakefulness in association with increased physical activity during the awake phase, and these changes may underlie the amelioration of glucose metabolism under type 2 diabetic conditions.

Sarcopenia in a type 2 diabetic state: Reviewing literature on the pathological consequences of oxidative stress and inflammation beyond the neutralizing effect of intracellular antioxidants

Sarcopenia remains one of the major pathological features of type 2 diabetes (T2D), especially in older individuals. This condition describes gradual loss of muscle mass, strength, and function that reduces the overall vitality and fitness, leading to increased hospitalizations and even fatalities to those affected. Preclinical evidence indicates that dysregulated mitochondrial dynamics, together with impaired activity of the NADPH oxidase system, are the major sources of oxidative stress that drive skeletal muscle damage in T2D. While patients with T2D also display relatively higher levels of circulating inflammatory markers in the serum, including high sensitivity-C-reactive protein, interleukin-6, and tumor necrosis factor-α that are independently linked with the deterioration of muscle function and sarcopenia in T2D. In fact, beyond reporting on the pathological consequences of both oxidative stress and inflammation, the current review highlights the importance of strengthening intracellular antioxidant systems to preserve muscle mass, strength, and function in individuals with T2D.

A Korean Nationwide Cross-Sectional Study Investigating Risk Factors, Prevalence, and Characteristics of Sarcopenia in Men in Early Old Age

The present study investigated the risk factors, prevalence, and characteristics of sarcopenia among men aged 50-64 years. A total of 2868 participants were enrolled in this study. Of these, 328 individuals were classified into a sarcopenia group; the remaining 2540 were assigned to a control group. This study examined several variables, including skeletal muscle mass index, age, height, weight, body mass index, waist circumference, systolic and diastolic blood pressure, fasting glucose, triglyceride and total cholesterol levels, alcohol consumption, and tobacco use. It employed a stratified, clustered, and multistage probability sampling design. Complex sampling was used for the data analysis. The prevalence of sarcopenia was 10.25% (95% CI: 8.98-11.69). All anthropometric measures, including height, weight, BMI, and waist circumference, were significantly different between the two groups (p < 0.05). In terms of blood pressure, only systolic blood pressure (SBP) was significant (p < 0.05), and fasting glucose and triglyceride levels were risk factors for sarcopenia (p < 0.05). Tobacco use differed significantly between the two groups (p < 0.05). This study reported the specific prevalence of sarcopenia and identified its risk factors among men in early old age.

Sex Differences in the Skeletal Muscle Response to a High Fat, High Sucrose Diet in Rats

Men are diagnosed with type 2 diabetes at lower body mass indexes than women; the role of skeletal muscle in this sex difference is poorly understood. Type 2 diabetes impacts skeletal muscle, particularly in females who demonstrate a lower oxidative capacity compared to males. To address mechanistic differences underlying this sex disparity, we investigated skeletal muscle mitochondrial respiration in female and male rats in response to chronic high-fat, high-sugar (HFHS) diet consumption. Four-week-old Wistar Rats were fed a standard chow or HFHS diet for 14 weeks to identify sex-specific adaptations in mitochondrial respirometry and characteristics, transcriptional patterns, and protein profiles. Fat mass was greater with the HFHS diet in both sexes when controlled for body mass (p < 0.0001). Blood glucose and insulin resistance were greater in males (p = 0.01) and HFHS-fed rats (p < 0.001). HFHS-fed males had higher mitochondrial respiration compared with females (p < 0.01 sex/diet interaction). No evidence of a difference by sex or diet was found for mitochondrial synthesis, dynamics, or quality to support the mitochondrial respiration sex/diet interaction. However, transcriptomic analyses indicate sex differences in nutrient handling. Sex-specific differences occurred in PI3K/AKT signaling, PPARα/RXRα, and triacylglycerol degradation. These findings may provide insight into the clinical sex differences in body mass index threshold for diabetes development and tissue-specific progression of insulin resistance.

"Does Physical Exercise Promote Health Benefits for Diabetic Patients during the COVID-19 Pandemic?": A Systematic Review

Patients affected by COVID-19 are prone to facing disorders in multiple systems and organs, which can lead to deleterious diseases; in addition, people with pre-existing diseases may be more prone to the worst outcomes, and the most vulnerable are patients with type 1 and type 2 diabetes mellitus. The aim of this systematic review was to evaluate the effects of physical activity and/or physical exercise prescribed to individuals with diabetes on the maintenance of plasma glucose and glycated hemoglobin during the COVID-19 pandemic. Studies were found by searching PubMed, SCOPUS, Embase, Web of Science, SciELO, LILACS, SportDiscus, Bireme/BVS and Google Scholar databases. The inclusion criteria were articles that addressed only patients with type 1 or type 2 diabetes (T1D and T2D) who had evaluated the level of physical activity or physical exercise and described the effects on plasma glucose and/or glycated hemoglobin in cross-sectional, retrospective, and observational studies, meeting the main criteria established by GRADE. The PICO and GRADE strategies were used to select and assess the methodological quality of studies. Two reviewers searched and selected the articles in databases independently and blindly, during which oppositions and disagreements about the inclusion of articles were discussed and resolved by a third reviewer. Evidence corroborates that levels of physical activity were reduced due to the lockdown, leading to increased body weight and worse glycemic control. On the other hand, individuals with diabetes mellitus (DM) (T1D and T2D) who maintained and/or increased levels of physical activity or physical exercise showed reduced plasma glucose and glycated hemoglobin (HbA1c) levels. Adequate levels of physical exercise and physical activity are beneficial for glucose and HbA1c control in diabetic patients (type 1 or type 2). In addition, maintaining adequate levels of physical activity can contribute to reducing health problems when these patients are infected with COVID-19.

Advances in Research on Type 2 Diabetes Mellitus Targets and Therapeutic Agents

Diabetes mellitus is a chronic multifaceted disease with multiple potential complications, the treatment of which can only delay and prolong the terminal stage of the disease, i.e., type 2 diabetes mellitus (T2DM). The World Health Organization predicts that diabetes will be the seventh leading cause of death by 2030. Although many antidiabetic medicines have been successfully developed in recent years, such as GLP-1 receptor agonists and SGLT-2 inhibitors, single-target drugs are gradually failing to meet the therapeutic requirements owing to the individual variability, diversity of pathogenesis, and organismal resistance. Therefore, there remains a need to investigate the pathogenesis of T2DM in more depth, identify multiple therapeutic targets, and provide improved glycemic control solutions. This review presents an overview of the mechanisms of action and the development of the latest therapeutic agents targeting T2DM in recent years. It also discusses emerging target-based therapies and new potential therapeutic targets that have emerged within the last three years. The aim of our review is to provide a theoretical basis for further advancement in targeted therapies for T2DM.

Gender-Specific Prevalence and Risk Factors of Sarcopenic Obesity in the Korean Elderly Population: A Nationwide Cross-Sectional Study

Sarcopenic obesity (SO) is characterized by the combination of sarcopenia and obesity. This study evaluates the gender-specific prevalence of SO and examines the identified gender-specific risk factors in a community-dwelling elderly population aged 75-84 years. A total of 813 subjects participated in the study via the Korea National Health and Nutrition Examination Survey. The SO prevalence in males and females was 15.46% (95%CI: 11.36-20.70) and 13.59% (95%CI: 10.59-17.28), respectively. The clinical sex-specific risk factors for males were low height, high weight, body mass index, waist circumference, skeletal muscle index, fasting glucose, and triglycerides. The clinical risk factors for females were low height, high weight, body mass index, waist circumference, skeletal muscle index, smoking status, fasting glucose, total cholesterol, and systolic blood pressure. These results are essential to assist healthcare professionals and primary care clinicians with early detection, diagnosis, and intervention for potential SO patients by acknowledging the sex-based prevalence and risk factors.

Tinosporaside from Tinospora cordifolia Encourages Skeletal Muscle Glucose Transport through Both PI-3-Kinase- and AMPK-Dependent Mechanisms

The stem of Tinospora cordifolia has been traditionally used in traditional Indian systems of medicine for blood sugar control, without the knowledge of the underlying mechanism and chemical constitution responsible for the observed anti-diabetic effect. In the present study, Tinosporaside, a diterpenoid isolated from the stem of T. cordifolia, was investigated for its effects on glucose utilization in skeletal muscle cells, which was followed by determining the anti-hyperglycemic efficacy in our diabetic db/db mice model. We found that tinosporaside augmented glucose uptake by increasing the translocation of GLUT4 to the plasma membrane in L6 myotubes, upon prolonged exposure for 16 h. Moreover, tinosporaside treatment significantly increased the phosphorylation of protein kinase B/AKT (Ser-473) and 5' AMP-activated protein kinase (AMPK, Thr-172). These effects were abolished in the presence of the wortmannin and compound C. Administration of tinosporaside to db/db mice improved glucose tolerance and peripheral insulin sensitivity associated with increased gene expression and phosphorylation of the markers of phosphoinositide 3-kinases (PI3Ks) and AMPK signaling in skeletal muscle tissue. The findings revealed that tinosporaside exerted its antidiabetic efficacy by enhancing the rate of glucose utilization in skeletal muscle, mediated by PI3K- and AMPK-dependent signaling mechanisms.

Effect of Carica papaya on IRS-1/Akt Signaling Mechanisms in High-Fat-Diet-Streptozotocin-Induced Type 2 Diabetic Experimental Rats: A Mechanistic Approach

Despite rigorous endeavors, existing attempts to handle type 2 diabetes (T2DM) are still a long way off, as a substantial number of patients do not meet therapeutic targets. Insulin resistance in skeletal muscle is discerned as a forerunner in the pathogenesis of T2DM and can be detected years before its progress. Studies have revealed the antidiabetic properties of Carica papaya (C. papaya), but its molecular mechanism on insulin receptor substrate-1 (IRS-1)/Akt signaling mechanisms is not yet known. The present study aimed to evaluate the role of C. papaya on IRS1 and Akt in high-fat-diet-streptozotocin-induced type 2 diabetic rats and also to analyze the bioactive compounds of C. papaya against IRS-1 and Akt via in silico analysis. Ethanolic extract of the leaves of C. papaya (600 mg/kg of body weight) was given daily for 45 days postinduction of T2DM up to the end of the study. Gluconeogenic enzymes, glycolytic enzymes, gene expression, and immunohistochemical analysis of IRS-1 and Akt in skeletal muscle were evaluated. C. papaya treatment regulated the levels of gluconeogenic and glycolytic enzymes and the levels of IRS-1 and Akt in skeletal muscle of type 2 diabetic animals. In silico studies showed that trans-ferulic acid had the greatest hit rate against the protein targets IRS-1 and Akt. C. papaya restored the normoglycemic effect in diabetic skeletal muscle by accelerating the expression of IRS-1 and Akt.

Gender-Specific Risk Factors and Prevalence for Sarcopenia among Community-Dwelling Young-Old Adults

Sarcopenia in the elderly is a serious global public health problem. Numerous sarcopenia studies classified their subjects into a single group, but health conditions and body composition vary according to age. This study examined the prevalence of sarcopenia according to gender and assessed the gender-specific risk factors in young-old adults. In this study, 2697 participants in Korea aged from 65 to 74 years were analyzed from Korea National Health and Nutrition Examination Surveys. The prevalence of sarcopenia in males and females was 19.2% (CI 95%: 16.4–22.3) and 26.4% (23.7–29.4), respectively. The risk factors in men were age, body mass index (BMI), waist circumference (WC), skeletal muscle index (SMI), fasting glucose (FG), triglyceride, and systolic blood pressure (SBP). Their odd ratios were 1.447, 0.102, 1.494, 0.211, 0.877, 1.012, and 1.347. The risk factors in women were age, height, weight, BMI, WC, SMI, and fasting glucose with values of 1.489, 0.096, 0.079, 0.158, 0.042, and 1.071, respectively. The prevalence of sarcopenia was higher in females than in males. Overall, the clinical risk factors in males were age, height, BMI, WC, SMI, FG, triglyceride, and SBP. Age, height, weight, BMI, WC, SMI, and FG were the risk factors for women.