Role of physical activity and cardiorespiratory fitness in metabolically healthy obesity: a narrative review

Obesity has been associated with a multitude of metabolic disorders, often clustering with risk factors of cardiovascular disease and type 2 diabetes mellitus, hypertension, dyslipidaemia. Overall, obesity is a worldwide, growing health concern. However, a subgroup of obese individuals with a low burden of metabolic abnormalities have been identified and described as metabolically healthy obese (MHO). Whether the MHO phenotype is protective against obesity-related metabolic disorders in the long-term is presently unclear, and current research examining the potential transition has yielded inconsistent results. In this current narrative review, we aim to provide insights on the role of physical activity (PA) and cardiorespiratory fitness (CRF) in MHO. Lifestyle factors such as PA and CRF may influence the MHO phenotype. Limited studies have characterised energy expenditure and CRF in MHO and metabolically unhealthy obese. However, higher levels of PA, less sedentary behaviour and higher CRF have been observed in MHO individuals. Considering the multiple benefits of PA, it is high time to advocate this lifestyle change beyond its influence on energy balance in a weight loss programme to improve cardiovascular and metabolic risk factors irrespective of body weight and fat mass changes. Improved CRF via increased PA, especially exercise participation, while avoiding weight gain is not only a realistic goal, but should be the primary intervention for MHO populations to prevent the transition to an abnormal metabolic state

Tobacco Use and Its Health Effects among Professional Athletes in Qatar

The objective of the study was to determine the effects of tobacco use on selected markers of health and lung function in professional athletes. A total of 108 male professional athletes participated in the study from ten ball game teams in the same sport league in Qatar (age = 26.4 ± 5.1 yrs, height = 190.6 ± 11.9 cm, and weight = 91.5 ± 16.4 kg). The athletes have been playing professionally for about 6.3 years on average. In addition to demographic and tobacco use status, the following clinical variables were measured: resting blood pressure, heart rate, FVC, FEV1 sec, and PEF. The prevalence of tobacco use among the athletes was 27.7%. The FVC, FVC%, and FEV1% were significantly lower among the smokers compared to the nonsmokers ( = 0.003, 0.044, and 0.001, resp.). There were no significant differences between cigarettes smokers and nonsmokers in BP, HR, FEV1, FEV1/FVC, PEF, and PEF%. Similarly, those who smoked shisha had lower FEV1% values as compared to those who did not smoke shisha ( = 0.001). The decrease of FEV1 and FVC among smokers compared to nonsmokers is similar to what has been reported in the literature about other populations.Scopu

SIRT1 may play a crucial role in overload-induced hypertrophy of skeletal muscle

Silent mating type information regulation 2 homologue 1 (SIRT1) activity and content increased significantly in overload-induced hypertrophy. SIRT1-mediated signalling through Akt, the endothelial nitric oxide synthase mediated pathway, regulates anabolic process in the hypertrophy of skeletal muscle. The regulation of catabolic signalling via forkhead box O 1 and protein ubiquitination is SIRT1 dependent. Overload-induced changes in microRNA levels regulate SIRT1 and insulin-like growth factor 1 signalling. Significant skeletal muscle mass guarantees functional wellbeing and is important for high level performance in many sports. Although the molecular mechanism for skeletal muscle hypertrophy has been well studied, it still is not completely understood. In the present study, we used a functional overload model to induce plantaris muscle hypertrophy by surgically removing the soleus and gastrocnemius muscles in rats. Two weeks of muscle ablation resulted in a 40% increase in muscle mass, which was associated with a significant increase in silent mating type information regulation 2 homologue 1 (SIRT1) content and activity (P < 0.001). SIRT1-regulated Akt, endothelial nitric oxide synthase and GLUT4 levels were also induced in hypertrophied muscles, and SIRT1 levels correlated with muscle mass, paired box protein 7 (Pax7), proliferating cell nuclear antigen (PCNA) and nicotinamide phosphoribosyltransferase (Nampt) levels. Alternatively, decreased forkhead box O 1 (FOXO1) and increased K48 polyubiquitination also suggest that SIRT1 could be involved in the catabolic process of hypertrophy. Furthermore, increased levels of K63 and muscle RING finger 2 (MuRF2) protein could also be important enhancers of muscle mass. We report here that the levels of miR1 and miR133a decrease in hypertrophy and negatively correlate with muscle mass, SIRT1 and Nampt levels. Our results reveal a strong correlation between SIRT1 levels and activity, SIRT1-regulated pathways and overload-induced hypertrophy. These findings, along with the well-known regulatory roles that SIRT1 plays in modulating both anabolic and catabolic pathways, allow us to propose the hypothesis that SIRT1 may actually play a crucial causal role in overload-induced hypertrophy of skeletal muscle. This hypothesis will now require rigorous direct and functional testing.National Strength and Conditioning Association OTKA. Grant Number: 112810 Hungarian Academy of Science National Institute of Environmental Health Sciences. Grant Number: ES00359

Paclitaxel Protects against Isoproterenol-Induced Damage in Rat Myocardium: Its Heme-Oxygenase Mediated Role in Cardiovascular Research

(1) Background: In cardiovascular applications, paclitaxel inhibits smooth muscle cell proliferation and migration and significantly reduces the occurrence of restenosis and target lesion revascularization. However, the cellular effects of paclitaxel in the myocardium are not well understood; (2) Methods: Wistar rats were divided into four groups: control (CTRL), isoproterenol (ISO) treated (1 mg/kg) and two groups treated with paclitaxel (PAC), which was administrated (10 mg/kg/day) for 5 days by gavage/per os alone or in combination (ISO + PAC) 3 weeks after ISO treatment. Ventricular tissue was harvested 24 h later for measurements of heme oxygenase (HO-1), reduced glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), NF-κB, TNF-α and myeloperoxidase (MPO); (3) Results: HO-1 protein concentration, HO-1 activity, SOD protein concentration and total glutathione significantly decreased in response to ISO treatment. When PAC was administered in conjunction with ISO, HO-1, SOD concentration and total glutathione were not different from control levels. MPO activity, NF-κB concentration and TNF-α protein concentration were significantly increased in the ISO-only group, while the levels of these molecules were restored when PAC was co-administered; (4) Conclusions: Oral administration of PAC can maintain the expression of important antioxidants, anti-inflammatory molecules, HO-1, SOD and GSH, and suppress the production of TNF-α, MPO and NF-κB, which are involved in myocardial damage. The principal component of this cellular defense seems to be the expression of HO-1

Nitrát tolerancia a szívizomban = Nitrate tolerance in the myocardium

Nagy dózisú nitroglicerin ismételt alkalmazásával vaszkuláris nitrát toleranciát váltottunk ki kísérleti állatokban. Kimutattuk hogy vaszkuláris nitrát toleranciában a szív és az aorta génexpressziós profilja eltérően változik. A szívizom génexpressziós változását egyéb szisztémás metabolikus állapotokban (metabolikus szindróma) is leírtuk. Kimutattuk, hogy az iszkémiás posztkondícionálás infarktus méretet csökkentő hatása jelentősen mérséklődik vaszkuláris nitrát tolerancia fennállása esetén. Továbbá azt tapasztaltuk, hogy ez a jelenség független a túlélő kinázok aktiválódásától. Kísérletes urémiában viszont a prekondícionálás kardioprotektív hatása megtartott marad. Izolált perfundált szívekben kimutattuk, hogy mind a koronária lekötés előtt, mind pedig a reperfúzió előtt megkezdett nitroglicerin perfúzió csökkenti a kialakuló infarktus méretét. Azonban a nitroglicerinnek ez a kardioprotektív hatása vaszkuláris nitrát tolerancia fennállása esetén nem volt megfigyelhető. Igazoltuk, hogy a NO-donor SNAP védi a szimulált iszkémia/reoxigenizációnak kitett primer szívizomsejt tenyészeteket a sejtelhalástól, valószínűleg részben a cGMP-PKG jelátviteli útvonal aktiválása révén. Továbbá kimutattuk, hogy a reperfúzió kezdetén alkalmazott szakaszos nagyfrekvenciás ingerléssel is kiváltható posztkondícionáló hatás a szívben. | We have induced vascular nitrate tolerance in rats by repeated administration of high dose nitroglycerin. We have found that the gene expression profile of the heart and the aorta was differentially altered in response to the development of vascular nitrate tolerance. Alterations in cardiac gene expression were shown in other systemic metabolic conditions (i.e. metabolic syndrome) as well. We have shown that the infarct size limiting effect of ischemic postconditioning is attenuated in the state of vascular nitrate tolerance. Moreover, we have found that this phenomenon is independent of survival kinase activation. Experimental uremia. however, did not lead to the loss of ischemic preconditioning. We have demonstrated in ex vivo hearts that nitroglycerin perfusion decreased infarct size when started before coronary occlusion and also when only started before reperfusion. This cardioprotective effect of nitroglycerin was diminished in the state of vascular nitrate tolerance. We have shown that the NO-donor molecule SNAP is able to protect primary cardiomyocyte cultures against simulated ischemia/reperfusion at least in part via activation of cGMP-PKG signaling. We have found that a postconditioning effect can be induced by applying short periods of ventricular overdrive pacing at the onset of reperfusion

Anti-Inflammatory Effect of Recreational Exercise in TNBS-Induced Colitis in Rats: Role of NOS/HO/MPO System

There are opposite views in the available literature: Whether physical exercise has a protective effect or not on the onset of inflammatory bowel disease (IBD). Therefore, we investigated the effects of recreational physical exercise before the induction of colitis. After 6 weeks of voluntary physical activity (running wheel), male Wistar rats were treated with TNBS (10 mg). 72 hrs after trinitrobenzene sulphonic acid (TNBS) challenge we measured colonic gene (TNF-, IL-1 , CXCL1 and IL-10) and protein (TNF-) expressions of various inflammatory mediators and enzyme activities of heme oxygenase (HO), nitric oxide synthase (NOS), and myeloperoxidase (MPO) enzymes. Wheel running significantly increased the activities of HO, constitutive NOS (cNOS) isoform. Furthermore, 6 weeks of running significantly decreased TNBS-induced inflammatory markers, including extent of lesions, severity of mucosal damage, and gene expression of IL-1 , CXCL1, and MPO activity, while IL-10 gene expression and cNOS activity were increased. iNOS activity decreased and the activity of HO enzyme increased, but not significantly, compared to the sedentary TNBS-treated group. In conclusion, recreational physical exercise can play an anti-inflammatory role by downregulating the gene expression of proinflammatory mediators, inducing anti-inflammatory mediators, and modulating the activities of HO and NOS enzymes in a rat model of colitis

The role of heat shock proteins in skeletal muscle adaptation to resistance training in young and old rats.

Heat shock proteins (HSP\u27s) are expressed in response to various stressors, such as physical exercise, therefore this study investigated the role of these proteins in skeletal muscle remodeling in response to resistance training. First, we determined the time course of HSP response as a result of a single bout of damaging contractions characterized by non-recoverable force deficit. The next study investigated HSP expression in 3 month old and 30 month old rats in response to a 4.5-week, chronic resistance training program that was designed to elicit muscle hypertrophy. Moreover, we analyzed the gene expression of four hsp70 genes to determine whether resistance training differentially affects the transcription of these genes. The results of the first study showed that HSP25 and HSP72 proteins increased significantly (p \u3c 0.01) in the injured TA muscles compared to control muscles by 48 h and remained elevated at 240h post-injury. Isometric force was significantly lower than control levels 48h post injury but it returned to control measures by 120h and continued to recover by 240h post-injury. This study demonstrated that skeletal muscle injury induced the expression of HSP25 and HSP72, which remained elevated even after the full recovery of isometric force to pre-injury levels. These data are consistent with the hypothesis that HSP\u27s have a role in skeletal muscle remodeling following eccentric contraction-induced damage. The second investigation indicated that muscle wet weight of the left TA increased by 15.6% in young animals compared to the untrained side, while the aged rats demonstrated no significant hypertrophy based on muscle wet weight. A significant training effect was found for both stress proteins. On the other hand, there was no training by age interaction for HSP72, while a significant training by age effects were found in muscles for HSP25. We demonstrated in this investigation that both young and old animals are capable of increasing HSP72 expression in response to high intensity stress. However, it is possible that the underlying cellular mechanisms of stress protein induction might differ between these age groups