Brain-derived neurotrophic factor, insulin like growth factor-1 and inflammatory cytokine responses to continuous and intermittent exercise in patients with type 1 diabetes

The Brain-Gut-Bone Axis in Neurodegenerative Diseases: Insights, Challenges, and Future Prospects

Neurodegenerative diseases are global health challenges characterized by the progressive degeneration of nerve cells, leading to cognitive and motor impairments. The brain-gut-bone axis, a complex network that modulates multiple physiological systems, has gained increasing attention owing to its profound effects on the occurrence and development of neurodegenerative diseases. No comprehensive review has been conducted to clarify the triangular relationship involving the brain-gut-bone axis and its potential for innovative therapies for neurodegenerative disorders. In light of this, a new perspective is aimed to propose on the interplay between the brain, gut, and bone systems, highlighting the potential of their dynamic communication in neurodegenerative diseases, as they modulate multiple physiological systems, including the nervous, immune, endocrine, and metabolic systems. Therapeutic strategies for maintaining the balance of the axis, including brain health regulation, intestinal microbiota regulation, and improving skeletal health, are also explored. The intricate physiological interactions within the brain-gut-bone axis pose a challenge in the development of effective treatments that can comprehensively target this system. Furthermore, the safety of these treatments requires further evaluation. This review offers a novel insights and strategies for the prevention and treatment of neurodegenerative diseases, which have important implications for clinical practice and patient well-being.

Physical exercise regulates microglia in health and disease

There is a well-established link between physical activity and brain health. As such, the effectiveness of physical exercise as a therapeutic strategy has been explored in a variety of neurological contexts. To determine the extent to which physical exercise could be most beneficial under different circumstances, studies are needed to uncover the underlying mechanisms behind the benefits of physical activity. Interest has grown in understanding how physical activity can regulate microglia, the resident immune cells of the central nervous system. Microglia are key mediators of neuroinflammatory processes and play a role in maintaining brain homeostasis in healthy and pathological settings. Here, we explore the evidence suggesting that physical activity has the potential to regulate microglia activity in various animal models. We emphasize key areas where future research could contribute to uncovering the therapeutic benefits of engaging in physical exercise.

The anti-inflammatory effects of exercise on autoimmune diseases: A 20-year systematic review

BACKGROUND

The anti-inflammatory effect of exercise may be an underlying factor in improving several autoimmune diseases. The aim of this systematic review was to examine the evidence on the role of exercise training in mitigating inflammation in adolescents and adults with autoimmune disease.

METHODS

PubMed, Web of Science, and Embase databases were systematically reviewed for related studies published between January 1, 2003, and August 31, 2023. All randomized and non-randomized controlled trials of exercise interventions with autoimmune disease study participants that evaluated inflammation-related biomarkers were included. The quality of evidence was assessed using the Tool for the assEssment of Study qualiTy and reporting in EXercise scale and Cochrane bias risk tool.

RESULTS

A total of 14,565 records were identified. After screening the titles, abstracts, and full texts, 87 were eligible for the systematic review. These studies were conducted in 25 different countries and included a total of 2779 participants (patients with autoimmune disease, in exercise or control groups). Overall, the evidence suggests that inflammation-related markers such as C-reactive protein, interleukin 6, and tumor necrosis factor α were reduced by regular exercise interventions. Regular exercise interventions combined with multiple exercise modes were associated with greater benefits.

CONCLUSION

Regular exercise training by patients with autoimmune disease exerts an anti-inflammatory influence. This systematic review provides support for the promotion and development of clinical exercise intervention programs for patients with autoimmune disease. Most patients with autoimmune disease can safely adopt moderate exercise training protocols, but changes in inflammation biomarkers will be modest at best. Acute exercise interventions are ineffective or even modestly but transiently pro-inflammatory.

The clinical features and potential mechanisms of cognitive disorders in peripheral autoimmune and inflammatory diseases

According to a study from World Health Organization's Global Burden of Disease, mental and neurological disorders have accounted for 13% of global diseases in recent years and are on the rise. Neuropsychiatric conditions or neuroinflammatory disorders are linked by the presence of an exaggerated immune response both peripherally and in the central nervous system (CNS). Cognitive dysfunction (CD) encompasses a complex group of diseases and has frequently been described in the field of autoimmune diseases, especially in multiple non-CNS-related autoimmune diseases. Recent studies have provided various hypotheses regarding the occurrence of cognitive impairment in autoimmune diseases, including that abnormally activated immune cells can disrupt the integrity of the blood-brain barrier (BBB) to trigger a central neuroinflammatory response. When the BBB is intact, autoantibodies and pro-inflammatory molecules in peripheral circulation can enter the brain to activate microglia, inducing CNS inflammation and CD. However, the mechanisms explaining the association between the immune system and neural function and their contribution to diseases are uncertain. In this review, we used clinical statistics to illustrate the correlation between CD and autoimmune diseases that do not directly affect the CNS, summarized the clinical features and mechanisms by which autoimmune diseases trigger cognitive impairment, and explored existing knowledge regarding the link between CD and autoimmune diseases from the perspective of the field of neuroimmunology.

Clinical effects and biological mechanisms of exercise on lumbar disc herniation

Lumbar Disc Herniation (LDH) is a syndrome in which lumbar disc degeneration, rupture of the annulus fibrosus, and herniation of the nucleus pulposus irritate and compress the nerve roots and cauda equina, resulting in the main manifestations of lumbar pain and/or lower extremity pain. There is evidence in various clinical areas that exercise is effective in treating LDH, and exercise intervention for more than 2 weeks reduces disease activity in LDH. However, the mechanism of exercise's action in reducing disease activity in LDH is unclear. In this article, we first summarize and highlight the effectiveness of exercise in treating LDH and provide guideline recommendations regarding exercise type, intensity, frequency, and duration. Then, we integrate the existing evidence and propose biological mechanisms for the potential effects of exercise on neuromechanical compression, inflammatory chemical stimuli, and autoimmune responses from the perspective of LDH pathogenesis as an entry point. However, a large body of evidence was obtained from non-LDH populations. Future research needs to investigate further the proposed biological mechanisms of exercise in reducing disease activity in LDH populations. This knowledge will contribute to the basic science and strengthen the scientific basis for prescribing exercise therapy for the routine clinical treatment of LDH.

Influence of Anaerobic Exercise in Type 1 Diabetes Mellitus Biomarkers: ASystematic Review

AIM

Physical exercise is part of the type 1 diabetes mellitus (T1DM) treatment. However, this practice is still neglected due to the wide variety of glycemic responses under the influence of anaerobic exercise. Therefore, this study aimed to investigate the influence of anaerobic exercise on biomarkers of T1DM.

METHODS

The systematic review was conducted on PubMed, Lilacs, and Embase, according to PRISMA. For this purpose, three groups of descriptors were used: Adults with T1DM, anaerobic physical exercise, and glycemic control. The search filter was set to human beings older than 18 years of age, longitudinal and cross-sectional studies, with studies published from 2000 to 2023 in English, Spanish, or Portuguese. Titles and abstracts were read independently by two reviewers, and then the articles were selected for this review. The Kappa coefficient was measured to evaluate the selection.

RESULTS

A total of 738 articles were identified, and five were selected to be part of the review after applying the steps of the procedure. Some benefits were observed in fatigue reduction, absence of diabetic ketoacidosis requiring hospitalization, and enhancement of glucose monitoring during exercise. In the anaerobic workouts of the groups with T1DM, glycemic mean values ranged from 124.5-185.0 mg/dl, and glycated hemoglobin records ranged from 6.7-8.1%.

CONCLUSION

Anaerobic exercise improved the biomarkers of T1DM, especially glycemic control, and the reduction of symptomatic hypoglycemic episodes. Anaerobic exercise can be performed by individuals with T1DM, suggesting an individualized training prescription and encouraging its practice associated with aerobic exercise.

Effect of concurrent resistance-aerobic training on inflammatory factors and growth hormones in children with type 1 diabetes: a randomized controlled clinical trial

BACKGROUND

Exercise training is a major factor in controlling type 1 diabetes mellitus (T1DM) in children. The present study aimed to assess the effect of concurrent resistance-aerobic training on selected inflammatory factors and hormones related to blood glucose homeostasis in children with T1DM.

METHODS

In this randomized controlled clinical trial, 40 children (with the mean age of 11.11 ± 2.29 years) were randomly assigned to an experimental (N = 20) or control group (N = 20). They underwent a 16-week training program, composed of concurrent resistance-aerobic training performed intermittently for 60 min three times a week. Before and after training, blood samples were analyzed for glucose homeostasis, selected inflammatory factors, and growth factors. Data were analyzed by paired t-test and analysis of covariance (ANCOVA) in IBM SPSS version 22.

RESULTS

The exercise training intervention reduced fasting blood sugar index (P = 0.002) and glycosylated hemoglobin significantly (P = 0.003). The growth hormone levels were increased significantly only in the experimental group (P = 0.037), whereas no significant difference was noted in the insulin-like growth factor-1 (P = 0.712). It was also found that interleukin-1β and high-sensitivity C-reactive protein did not change in the experimental or control group as compared to the pretest (P > 0.05).

CONCLUSION

As it was shown, it seems that concurrent resistance-aerobic training may improve blood glucose homeostasis and growth hormone. Therefore, these findings may suggest the benefit from exercise training of moderate intensity in children with T1DM. Besides, we recommend undertaking further clinical trials to determine if the exercise training was effective.

TRIAL REGISTRATION

This study was registered in the Iranian Registry of Clinical Trials under the code IRCT20150531022498N30: https://en.irct.ir/trial/41031 . Registered on July 26, 2019. All experiments on the participants were following the Declaration of Helsinki.

Acute effect of moderate and high-intensity interval exercises on asprosin and BDNF levels in inactive normal weight and obese individuals

This study aimed to examine the acute effects of moderate-intensity aerobic and high-intensity interval exercise protocols on Asprosin and Brain-Derived Neurotrophic Factor (BDNF) levels in inactive normal weight and obese individuals. A total of 20 male individuals aged 18-65 years, ten normal weight (NW) (Body Mass Index (BMI): 18.5-24.99 kg/m²) and 10 obese (Ob) (BMI: 24.99-35.00 kg/m²) participated in this study, voluntarily. Moderate aerobic exercise (AE) (main circuit 30 min, between 40 and 59% of Heart Rate Reserve: HRR) and High-Intensity Interval exercise (HIIE) running protocols (main circuit 20 min, between 75 and 90% of the HRR for 1 min*10 times, and 1-min active rest at 30% of the HRR) was applied to the volunteer participants in the morning hours (08.00-10.00 a.m.), following the night fasting (at least 8-10 h) for at least 3 days between each other. Blood samples were collected from the participants before and immediately after each exercise protocol, and serum asprosin and BDNF hormone levels were determined by Enzyme-Linked Immunosorbent Assay" method. Basal serum asprosin was found to be significantly higher in the Ob group compared to the NW group (p < .001), while the basal serum BDNF hormone was found to be lower (p < 0.05). It was observed that the serum asprosin level of both groups decreased significantly after both AE and HIIE protocols (p < 0.05). In addition, there was a significantly higher decrease in serum asprosin level in the Ob group compared to the NW group after HIIE protocol. For the Ob group, serum BDNF level increased considerably after HIIE protocol compared to AE protocol (p < 0.05). Serum asprosin was found to be higher in the Ob group, while the serum BDNF was found to be lower. In addition, the acute exercises of different intensity significantly affected hormones that regulate appetite metabolism. In particular, it was observed that the HIIE protocol had a greater effect on the regulation of appetite (hunger-satiety) in the Ob group. This result can be taken into account when planning training programs for these individuals.

Systematic Review and Meta-analysis of Blood Glucose Response to High-intensity Interval Exercise in Adults With Type 1 Diabetes

OBJECTIVES

Exercise-induced hyperglycemia is recognized in type 1 diabetes (T1D) clinical guidelines, but its association with high-intensity intermittent exercise (HIIE) in acute studies is inconsistent. In this meta-analysis, we examined the available evidence of blood glucose responses to HIIE in adults with T1D. The secondary, aim was to examine predictors of blood glucose responses to HIIE. We hypothesized that there would be no consistent effect on blood glucose from HIIE, unless examined in the context of participant prandial status.

METHODS

We conducted a literature search using key words related to T1D and HIIE. Studies were required to include at least 6 participants with T1D with a mean age >18 years, involve an HIIE intervention, and contain pre- and postexercise measures of blood glucose. Analyses of extracted data were performed using a general inverse variance statistical method with a random effects model and a weighted multiple regression.

RESULTS

Nineteen interventions from 15 reports were included in the analysis. A mean overall blood glucose decrease of -1.3 mmol/L (95% confidence interval [CI], -2.3 to -0.2 mmol/L) was found during exercise, albeit with high heterogeneity (I²=84%). When performed after an overnight fast, exercise increased blood glucose by +1.7 mmol/L (95% CI, 0.4 to 3.0 mmol/L), whereas postprandial exercise decreased blood glucose by -2.1 mmol/L (95% CI, -2.8 to -1.4 mmol/L), with a statistically significant difference between groups (p<0.0001). No associations with fitness (p=0.4), sex (p=0.4), age (p=0.9), exercise duration (p=0.9), or interval duration (p=0.2) were found.

CONCLUSION

The effect of HIIE on blood glucose is inconsistent, but partially explained by prandial status.

Brain-derived neurotrophic factor in diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor expressed in several tissues, including the brain, gut, and pancreas. Activation of the BDNF/TrkB/CREB reduces hepatic gluconeogenesis, induces hepatic insulin signal transduction, and protects against pancreatic beta-cell loss in diabetes mellitus (DM). Several studies have investigated the possible association between BDNF and DM and its complications, but the results have been conflicting.

AIM

In the present study, we aimed at systematically reviewing the literature on the serum and plasma levels of BDNF in DM and its subgroups such as T2DM, DM patients with depression, and patients with retinopathy.

METHODS

A comprehensive search was conducted in PubMed, Scopus, and Web of Science. We identified 28 eligible studies and calculated the standardized mean difference (SMD) of outcomes as an effect measure.

RESULTS

The meta-analysis included 2734 patients with DM and 6004 controls. Serum BDNF levels were significantly lower in patients with DM vs. controls (SMD = -1.00, P<0.001). Plasma BDNF levels were not different in patients with DM compared with controls. When conducting subgroup analysis, serum BDNF levels were lower among patients with T2DM (SMD = -1.26, P<0.001), DM and depression (SMD = -1.69, P<0.001), and patients with diabetic retinopathy (DR) vs. controls (SMD = -1.03, P = 0.01).

CONCLUSIONS

Serum BDNF levels were lower in patients with DM, T2DM, DM with depression, and DM and DR than the controls. Our findings are in line with the hypothesis that decreased BDNF levels might impair glucose metabolism and contribute to the pathogenesis of DM and its complications.

Exercise Training Enhances BDNF/TrkB Signaling Pathway and Inhibits Apoptosis in Diabetic Cerebral Cortex

This study aimed to clarify the therapeutic effects of exercise training on neural BDNF/TrkB signaling and apoptotic pathways in diabetic cerebral cortex. Thirty-six male C57BL/6JNarl mice were randomly divided into three groups: control (CON-G), diabetic group (DM-G, 100 mg/kg streptozotocin, i.p.), and diabetic with exercise training group (DMEX-G, Swim training for 30 min/day, 5 days/week). After 12 weeks, H&E staining, TUNEL staining, and Western blotting were performed to detect the morphological changes, neural apoptosis, and protein levels in the cerebral cortex. The Bcl2, BclxL, and pBad were significant decreased in DM-G compared with CON-G, whereas they (excluded the Ras and pRaf1) were increased in DMEX-G. In addition, interstitial space and TUNEL(+) apoptotic cells found increased in DM-G with increases in Fas/FasL-mediated (FasL, Fas, FADD, cleaved-caspase-8, and cleaved-caspase-3) and mitochondria-initiated (tBid, Bax/Bcl2, Bak/BclxL, Bad, Apaf1, cytochrome c, and cleaved-caspase-9) apoptotic pathways. However, diabetes-induced neural apoptosis was less in DMEX-G than DM-G with observed raises in the BDNF/TrkB signaling pathway as well as decreases in Fas/FasL-mediated and mitochondria-initiated pathways. In conclusion, exercise training provided neuroprotective effects via enhanced neural BDNF/TrkB signaling pathway and prevent Fas/FasL-mediated and mitochondria-initiated apoptotic pathways in diabetic cerebral cortex.

Nutrient-Response Pathways in Healthspan and Lifespan Regulation

Cellular, small invertebrate and vertebrate models are a driving force in biogerontology studies. Using various models, such as yeasts, appropriate tissue culture cells, Drosophila, the nematode Caenorhabditis elegans and the mouse, has tremendously increased our knowledge around the relationship between diet, nutrient-response signaling pathways and lifespan regulation. In recent years, combinatorial drug treatments combined with mutagenesis, high-throughput screens, as well as multi-omics approaches, have provided unprecedented insights in cellular metabolism, development, differentiation, and aging. Scientists are, therefore, moving towards characterizing the fine architecture and cross-talks of growth and stress pathways towards identifying possible interventions that could lead to healthy aging and the amelioration of age-related diseases in humans. In this short review, we briefly examine recently uncovered knowledge around nutrient-response pathways, such as the Insulin Growth Factor (IGF) and the mechanistic Target of Rapamycin signaling pathways, as well as specific GWAS and some EWAS studies on lifespan and age-related disease that have enhanced our current understanding within the aging and biogerontology fields. We discuss what is learned from the rich and diverse generated data, as well as challenges and next frontiers in these scientific disciplines.

A low serum IGF-1 is correlated with sarcopenia in subjects with type 1 diabetes mellitus: Findings from a post-hoc analysis of the iDIAMOND study

AIM

Our previous study revealed that sarcopenia was frequently observed in subjects with type 1 diabetes mellitus (T1DM). However, the factors associated with sarcopenia that are related to T1DM have not yet been clarified. Insulin-like growth factor-1 (IGF-1) has been shown to play a role in skeletal muscle growth, differentiation, and regeneration. The present study, therefore, investigated the association between the serum IGF-1 level and sarcopenia and low skeletal muscle mass in subjects with T1DM.

METHODS

This cross-sectional study enrolled subjects with T1DM (n = 168) and without diabetes (n = 59) who had had their clinical data on serum IGF-1 collected in the iDIAMOND study.

RESULTS

The z-score of serum IGF-1 was significantly lower in the subjects with T1DM than that in those without diabetes (p < 0.001). Among subjects with T1DM, the z-score of serum IGF-1 was significantly lower in sarcopenic subjects than in non-sarcopenic subjects. The multivariable logistic regression analysis showed that the serum IGF-1 z-score was an independent determinant of sarcopenia and a low skeletal muscle mass index, but not low grip strength nor slow gait speed in subjects with T1DM.

CONCLUSIONS

A low serum IGF-1 level is correlated with sarcopenia and low skeletal muscle mass in subjects with T1DM.

A systematic review and meta-analysis of association between brain-derived neurotrophic factor and type 2 diabetes and glycemic profile

Several epidemiologic studies have evaluated the relation between serum/plasma brain-derived neurotrophic factor (BDNF) levels and glycemic parameters, but the findings were conflicting. We performed a systematic review and meta-analysis to compare circulating BDNF levels in individuals with type 2 diabetes (T2D) or other glycemic disorders with healthy controls and to evaluate correlation between BDNF concentrations with glycemic profile. A systematic search up to July 2020 was conducted in reliable electronic databases (MEDLINE (Pubmed), EMBASE, Scopus) and Google scholar. Sixteen observational studies compared serum/plasma BDNF levels in diabetic patients (or individuals with glycemic disorders) vs. healthy controls or reported correlations between serum BDNF levels and glycemic parameters in adults were included in the review. Overall weighted mean difference (WMD) of circulating BDNF levels in 1306 patients with T2D (or other glycemic disorders) was 1.12 ng/mL lower than 1250 healthy subjects (WMD: − 1.12; 95%CI − 1.37, − 0.88, I² = 98.7%, P < 0.001). Subgroup analysis revealed that both diabetic patients and subjects with other glycemic disorders had lower serum/plasma BDNF levels than healthy controls (WMD: − 1.74; 95%CI − 2.15, − 1.33 and WMD: − 0.49; 95%CI − 0.82, − 0.16, respectively). No significant correlation was found between BDNF levels and glycemic parameters [fasting blood glucose (FBG) (Fisher’s Z = 0.05; 95%CI − 0.21, 0.11; n = 1400), homeostatic model assessment for insulin resistance (HOMA-IR) (Fisher’s Z = 0.12; 95%CI − 0.20, 0.44; n = 732) and glycosylated hemoglobin (HbA1c) (Fisher’s Z = 0.04; 95%CI − 0.05, 0.12; n = 2222)]. We found that diabetic patients and subjects with glycemic disorders had lower circulating BDNF levels than healthy controls. However, there was no significant correlation between BDNF concentrations and glycemic parameters including FBG, HOMA-IR and HbA1c. Further prospective investigations are required to confirm these findings.

Quercetin‑conjugated superparamagnetic iron oxide nanoparticles modulate glucose metabolism-related genes and miR-29 family in the hippocampus of diabetic rats

Quercetin (QC) is a dietary bioflavonoid that can be conjugated with nanoparticles to facilitate its brain bioavailability. We previously showed that quercetin-conjugated superparamagnetic iron oxide nanoparticles (QCSPIONs) reduced the level of blood glucose in diabetic rats. Glucose transporters (GLUTs), insulin-like growth factor-1 (IGF-1), and microRNA-29 (miR-29) play a critical role in brain glucose homeostasis. In the current study, we examined the effects of QCSPION on the expression of glucose metabolism-related genes, and the miR-29 family as a candidate regulator of glucose handling in the hippocampus of diabetic rats. Our in silico analyses introduce the miR-29 family as potential regulators of glucose transporters and IGF-1 genes. The expression level of the miR-29 family, IGF-1, GLUT1, GLUT2, GLUT3, and GLUT4 were measured by qPCR. Our results indicate that diabetes significantly results in upregulation of the miR-29 family and downregulation of the GLUT1, 2, 3, 4, and IGF-1 genes. Interestingly, QCSPIONs reduced miR-29 family expression and subsequently enhanced GLUT1, 2, 3, 4, and IGF-1expression. In conclusion, our findings suggest that QCSPION could regulate the expression of the miR-29 family, which in turn increases the expression of glucose transporters and IGF-1, thereby reducing diabetic complications.

Treadmill exercise mitigates neuroinflammation and increases BDNF via activation of SIRT1 signaling in a mouse model of T2DM

Although previous studies showed that exercise can improve cognitive dysfunction in type 2 diabetes (T2DM), the underlying mechanism remains unclear. Sirtuin 1 (SIRT1) has been shown to play a role in regulating inflammatory responses in the brain and increasing BDNF expression. This study investigated the effects of treadmill exercise on the hippocampal inflammatory response and BDNF expression in a T2DM mice model. We also tested whether these effects are SIRT1-dependent. In this study, C57BL/ 6 mice were used to construct T2DM model by a high-fat diet and STZ injection. We found that treadmill exercise for 8 weeks can significantly improve the cognitive dysfunction, alleviate activation of proinflammatory microglia M1 (Iba1 labeling) in the hippocampus of T2DM mice, and reduce the levels of proinflammatory factors IL-1β, IL-6, TNF-α, increase the expression levels of anti-inflammatory factors IL-10, TGF-β1, and promote the release of BDNF. We also found that exercise activate the signaling pathway of SIRT1/ NF-κB and SIRT1/ PGC-1α/ FNDC5/ BDNF. After the application of nicotinamide (NAM, SIRT1 inhibitor), the positive effects of exercise were remarkably suppressed. Our results showed that long-term moderate intensity treadmill exercise can alleviate inflammatory response in the hippocampus and increase BDNF expression in T2DM mice by activating SIRT1.

Treadmill exercise ameliorates chronic REM sleep deprivation-induced anxiety-like behavior and cognitive impairment in C57BL/6J mice

Various sleep disorders have deleterious effects on mental and cognitive performance. Exercise, as an alternative therapeutic strategy, exerts beneficial impacts on human health. In the present study, we aimed to evaluate the effects of 4 weeks treadmill exercise (4W-TE) on anxiety-like behavior and cognitive performance in mice exposed to 2 months REM sleep deprivation (2M-SD) (20 h per day). Behavioral performance of mice in elevated plus maze test (EPM), open field test (OFT), Y maze test (YM) and Morris water maze test (MWM) was recorded and analyzed 28 h after the last day of sleep deprivation. After behavioral tests, various neurotransmitters including norepinephrine (NE), dopamine (DA), serotonin (5-HT) and γ-aminobutyric acid (GABA) in mouse hippocampus were quantified using high performance liquid chromatography. The hippocampal levels of insulin-like growth factor-1 (IGF-1) and brain derived neurotrophic factor (BDNF) were further detected using ELISA. Behavioral data indicated that 2M-SD exposure induced anxiety-like behaviors and cognitive impairment, as evidenced by the decreased open-arm entries in EPM, reduced central area travels in OFT, declined spontaneous alteration in YM and prolonged escaping latency in MWM. In addition, 2M-SD exposure increased NE and DA, decreased 5-HT and GABA, and reduced IGF-1 and BDNF levels in mouse hippocampus. Interestingly, all these behavioral, neurochemical and neurobiological changes can be ameliorated by 4W-TE training. In summary, these findings confirm the beneficial impacts of exercise on health and provide further experimental evidence for future application of exercise as an alternative therapy against the mental and cognitive problems in patients with sleep disorders.

Moderate intensity exercise in hypoxia increases IGF-1 bioavailability and serum irisin in individuals with type 1 diabetes

AIM

This study aimed to determine the effect of moderate intensity continuous exercise (Ex) and hypoxia (Hyp) on serum brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3), irisin and cytokines levels in patients with type 1 diabetes (T1D).

METHODS

A total of 14 individuals with T1D (age: 28.7 ± 7.3 years) and 14 healthy adults (age: 27.1 ± 3.9 years) performed 40-min continuous Ex at moderate intensity (50% lactate threshold) on a cycle ergometer in normoxia (Nor) and Hyp (FiO₂ = 15.1%) Biochemical factors, glucose concentrations and physiological variables were measured at rest, immediately and up to 24 h after both Ex protocols.

RESULTS

Patients with T1D had significantly lower pre-Ex serum concentrations of BDNF (p < 0.05, p < 0.01), and total IGF-1 (p < 0.001, p < 0.05) and significantly higher irisin levels (p < 0.05, p < 0.01) in Nor and Hyp, compared with healthy subjects. Ex significantly increased in T1D group serum BDNF (in Nor only p < 0.05) and total IGF-1 levels in Nor and Hyp (p < 0.001 and p < 0.01, respectively). Immediately after Ex in Hyp, freeIGF-1 (p < 0.05) and irisin levels (p < 0.001) were significantly higher compared with the levels induced by Ex alone. Free IGF-1 and irisin serum levels remained elevated in 24 h post-Ex in Hyp. In T1D, significant blood glucose (BG) decrease was observed immediately after Ex in Hyp (p < 0.001) and in 24 h recovery (p < 0.001) compared with pre-Ex level.

CONCLUSION

The study results suggest that moderate intensity continuous Ex has beneficial effect on BDNF and IGF-1 levels. Ex in hypoxic conditions may be more effective in increasing availability of IGF-1. The alterations in the post-Ex irisin levels and IGF-1 system may be contributing to more effective glycaemia control in patients with T1D.

The beneficial effects of 15 units of high-intensity circuit training in women is modified by age, baseline insulin resistance and physical capacity

AIM

To investigate the effect of a single and 15 units of high-intensity circuit training (HICT) programme on glucose metabolism, myokines' response and selected genes' expression in women.

METHODS

Thirty-three, non-active women (mean age: 38 ± 12) were split into a HICT (n = 20) or a control group (CON, n = 13). The training protocol included three circuits of nine exercises with own body weight as a workload performed 3 times a week for five weeks. The CON group performed HICT twice. Blood samples were taken before, 1 h and 24 h after the first and last unit to determine IGF-1, myostatin, irisin, decorin, HSP27, interleukin-15 concentrations using the ELISA immunoenzymatic method. To evaluate HSPB1, TNF-α and DCN mRNA, real-time PCR was used. Pre- and post-intervention, the oral glucose test and body composition assessment were completed.

RESULTS

The following parameters tended to decrease after the 5-week HICT program: insulin and HOMA-IR Training diminished insulin/IGF-1 ratio (51% CI: -63% to -34%) and induced the drop of myostatin concentration but significantly only among middle-aged women and at baseline insulin resistance.

CONCLUSION

Obtained data revealed that HICT improved an insulin sensitivity and diminished myostatin concentration among older, insulin-resistant women with lower baseline physical capacity.

Differential Effects of Physical Exercise, Cognitive Training, and Mindfulness Practice on Serum BDNF Levels in Healthy Older Adults: A Randomized Controlled Intervention Study

Previous studies have indicated that an active lifestyle is associated with better brain health and a longer life, compared to a more sedentary lifestyle. These studies, both on human and animal subjects, have typically focused on a single activity, usually physical exercise, but other activities have received an increasing interest. One proposed mechanism is that physical exercise increases levels of brain-derived neurotrophic factor (BDNF) in the brain. For the first time, the long-term effects on serum BDNF levels were compared in persons who engaged in either physical exercise training, cognitive training, or mindfulness practice during 5 weeks, and compared with an active control group. Two cohorts of healthy older individuals, one from the Boston area in the US and one from the Växjö area in Sweden, participated. A total of 146 participants were randomly assigned to one of the four groups. All interventions were structurally similar, using interactive, computer-based software that directed participants to carry out specified activities for 35 minutes/day, 5 days per week for 5 weeks. Blood samples were obtained at baseline and soon after the completion of the 5-week long intervention program, and serum BDNF levels were measured using a commercially available ELISA. Only the group that underwent cognitive training increased their serum BDNF levels after 5 weeks of training (F1,74 = 4.22, p = 0.044, partial η2 = 0.054), corresponding to an average 10% increase. These results strongly suggest that cognitive training can exert beneficial effects on brain health in an older adult population.