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Cardiorespiratory fitness in children with overweight/obesity: Insights into the molecular mechanisms.
Plaza-Florido, A, Altmäe, S, Esteban, FJ, Löf, M, Radom-Aizik, S, Ortega, FB
Scandinavian journal of medicine & science in sports. 2021;(11):2083-2091
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OBJECTIVES High cardiorespiratory fitness (CRF) levels reduce the risk of developing cardiovascular disease (CVD) during adulthood. However, little is known about the molecular mechanisms underlying the health benefits of high CRF levels at the early stage of life. This study aimed to analyze the whole-blood transcriptome profile of fit children with overweight/obesity (OW/OB) compared to unfit children with OW/OB. DESIGN 27 children with OW/OB (10.14 ± 1.3 years, 59% boys) from the ActiveBrains project were evaluated. VO2 peak was assessed using a gas analyzer, and participants were categorized into fit or unfit according to the CVD risk-related cut-points. Whole-blood transcriptome profile (RNA sequencing) was analyzed. Differential gene expression analysis was performed using the limma R/Bioconductor software package (analyses adjusted by sex and maturational status), and pathways' enrichment analysis was performed with DAVID. In addition, in silico validation data mining was performed using the PHENOPEDIA database. RESULTS 256 genes were differentially expressed in fit children with OW/OB compared to unfit children with OW/OB after adjusting by sex and maturational status (FDR < 0.05). Enriched pathway analysis identified gene pathways related to inflammation (eg, dopaminergic and GABAergic synapse pathways). Interestingly, in silico validation data mining detected a set of the differentially expressed genes to be related to CVD, metabolic syndrome, hypertension, inflammation, and asthma. CONCLUSION The distinct pattern of whole-blood gene expression in fit children with OW/OB reveals genes and gene pathways that might play a role in reducing CVD risk factors later in life.
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The effects of canagliflozin compared to sitagliptin on cardiorespiratory fitness in type 2 diabetes mellitus and heart failure with reduced ejection fraction: The CANA-HF study.
Carbone, S, Billingsley, HE, Canada, JM, Bressi, E, Rotelli, B, Kadariya, D, Dixon, DL, Markley, R, Trankle, CR, Cooke, R, et al
Diabetes/metabolism research and reviews. 2020;(8):e3335
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BACKGROUND Canagliflozin reduces hospitalizations for heart failure (HF) in type 2 diabetes mellitus (T2DM). Its effect on cardiorespiratory fitness and cardiac function in patients with established HF with reduced ejection fraction (HFrEF) is unknown. METHODS We conducted a double-blind randomized controlled trial of canagliflozin 100 mg or sitagliptin 100 mg daily for 12 weeks in 88 patients, and measured peak oxygen consumption (VO2 ) and minute ventilation/carbon dioxide production (VE/VCO2 ) slope (co-primary endpoints for repeated measure ANOVA time_x_group interaction), lean peak VO2 , ventilatory anaerobic threshold (VAT), cardiac function and quality of life (ie, Minnesota Living with Heart Failure Questionnaire [MLHFQ]), at baseline and 12-week follow-up. RESULTS The study was terminated early due to the new guidelines recommending canagliflozin over sitagliptin in HF: 17 patients were assigned to canagliflozin and 19 to sitagliptin, total of 36 patients. There were no significant changes in peak VO2 and VE/VCO2 slope between the two groups (P = .083 and P = .98, respectively). Canagliflozin improved lean peak VO2 (+2.4 mL kgLM-1 min-1 , P = .036), VAT (+1.5 mL kg-1 min-1 , P = .012) and VO2 matched for respiratory exchange ratio (+2.4 mL Kg-1 min-1 , P = .002) compared to sitagliptin. Canagliflozin also reduced MLHFQ score (-12.1, P = .018). CONCLUSIONS In this small and short-term study of patients with T2DM and HFrEF, interrupted early after only 36 patients, canagliflozin did not improve the primary endpoints of peak VO2 or VE/VCO2 slope compared to sitagliptin, while showing favourable trends observed on several additional surrogate endpoints such as lean peak VO2 , VAT and quality of life.
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Oxygen saturation and heart rate in premature: comparison between cup and finger feeding techniques.
Nunes, JA, Bianchini, EMG, Cunha, MC
CoDAS. 2019;(6):e20180221
Abstract
PURPOSE To evaluate the oxygen saturation, heart rate, length of hospital stay and weight preterm infants or preterm newborns (PTNBs) (in the Neonatal Intensive Care Unit in the diet supply by cup and finger feeding techniques, simultaneously with breastfeeding. METHODS Simultaneous randomized clinical trial. Twenty-five preterm infants admitted to the Neonatal Intensive Care Unit of the Public Hospital from October 2011 to February 2012 were selected. The sample was divided into two groups: Eight preterm infants who received the diet in the cup probe group (CPG) who were born on the same day, and 17 by finger probe group (FPG) who were born on the odd day. In the diet offer, the minimum and maximum values of oxygen saturation (O2 Sat) and heart rate (HR) were recorded: before offering the diet, during and after the offer. RESULTS Regarding the variables O2 Sat and HR, no statistically significant differences were observed between the groups, but in the group vs time factor, the groups showed differences, not continuous in the O2 Sat variable. Regarding weight, a statistically significant gain was observed for both groups, and in CPG the highest weight gain was due to the longer hospitalization time. It was verified that FPG presented shorter hospitalization time. CONCLUSION There were no differences regarding O2 Sat and HR. However, when analyzing the time factor, the groups presented some differences, not continuous, indicating the need for other studies for a better understanding of the effect. The FPG presented shorter hospitalization time and the CPG infants had greater weight gain due to longer hospitalization time.
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Impact of l-citrulline supplementation on oxygen uptake kinetics during walking.
Ashley, J, Kim, Y, Gonzales, JU
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2018;(6):631-637
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Supplementation with l-citrulline (Cit) has been shown to improve muscle oxygenation and oxygen uptake kinetics during moderate- to high-intensity cycling in young men. The aim of this study was to test the hypothesis that Cit would improve oxygen uptake kinetics during walking in older and young adults. In a randomized, double-blind study, 26 (15 women, 11 men) adults between the ages of 20-35 years (n = 15) and 64-86 years (n = 11) completed 7-day periods of taking placebo and Cit (6 g/day) in a crossover manner. Participants walked on a treadmill at 40% heart rate reserve while pulmonary oxygen uptake was measured using indirect calorimetry. Net oxygen cost, mean response time (MRT), and the oxygen deficit were calculated before and after each supplement period. There was no significant change (P > 0.05) in net oxygen cost, MRT, or the oxygen deficit after Cit in older adults, while young adults showed a decrease (P = 0.05) in the oxygen deficit after Cit that tended (P = 0.053) to be different than the change after placebo. Sex-stratified analysis revealed that Cit decreased MRT (P = 0.04, Cohen's d = 0.41) and the oxygen deficit (P < 0.01, Cohen's d = 0.56) in men with the change after Cit being greater than the change after placebo (MRT: -4.5 ± 2.1 vs. 3.4 ± 2.1 s, P = 0.01; deficit: -0.15 ± 0.05 vs. 0.01 ± 0.05 L, P = 0.02). All oxygen uptake parameters were unchanged (P > 0.05) following Cit and placebo in women. Cit does not alter the oxygen cost of moderate-intensity walking in young or older adults, but Cit improved the rate of rise in oxygen uptake at exercise onset in men.
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Effects of the SGLT-2 Inhibitor Empagliflozin on Renal Tissue Oxygenation in Non-Diabetic Subjects: A Randomized, Double-Blind, Placebo-Controlled Study Protocol.
Muller, ME, Pruijm, M, Bonny, O, Burnier, M, Zanchi, A
Advances in therapy. 2018;(6):875-885
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INTRODUCTION Empagliflozin is an SGLT-2 inhibitor (SGLT-2i) which belongs to a new class of hypoglycemic drugs with the unique property of decreasing blood glucose independently from insulin, through an increase in glycosuria. In addition to decreasing cardiovascular morbidity and mortality, empagliflozin has nephroprotective properties in high cardiovascular risk patients with type 2 diabetes. Decreased hyperfiltration and shifting towards more favorable renal fuel energetics with improved renal oxygenation may explain some of these properties. With this study, we propose to explore the effects of empagliflozin on renal tissue oxygenation using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI). METHODS This is a double-blind, randomized, placebo-controlled study examining the acute and chronic renal effects of empagliflozin 10 mg. The primary outcome is the effects of empagliflozin on renal tissue oxygenation as measured by BOLD-MRI. The secondary outcomes include the effects of empagliflozin on tubular function, 24 h blood pressure control, and the influence of body mass index (BMI) on the renal response to empagliflozin. Fifteen normal weight, 15 overweight, and 15 obese non-diabetic subjects (men and women) will be recruited. Each participant will undergo 24 h urine collections and blood pressure measurements on day - 1, followed by an investigation day at the study center with blood and urine sampling and renal BOLD-MRI measurements before and 180 min after the administration of 10 mg empagliflozin or placebo. This sequence of measurements will be repeated after 1 month of a daily empagliflozin or placebo intake. To investigate renal oxygenation, the renal cortical and medullary R2*, as a marker of oxygenation, will be assessed by BOLD-MRI under standardized hydration conditions: the higher R2*, the lower oxygenation. CONCLUSION SGLT-2 inhibitors have a profound effect on renal physiology. This is an important study that will explore for the first time whether inhibiting SGLT-2 with empagliflozin in healthy volunteers affects renal tissue oxygenation as determined by BOLD-MRI. FUNDING Boehringer Ingelheim Pharma GmbH & Co. TRIAL REGISTRATION ClinicalTrials.gov identifier, NCT03093103.
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Assessing the effects of a short-term green tea intervention in skin microvascular function and oxygen tension in older and younger adults.
Wasilewski, R, Ubara, EO, Klonizakis, M
Microvascular research. 2016;:65-71
Abstract
Green tea consumption has been associated with a reduction in cardiovascular disease risk factors. However, there is little evidence examining its potential differing effect between younger and older populations, whilst little is known on its effect on the circulatory system when oxygen demand is higher. Therefore the aim of this study was to evaluate the short-term effects of green tea consumption on microvascular functioning in both an older and younger population. Fifteen young [24 (4.0)] and fifteen older [61 (4.0)] participants, consumed two cups of green tea daily for 14days. We used Laser Doppler Flowmetry (LDF) to assess cutaneous microvascular function and Transcutaneous Oxygen monitoring (TcPO2) to assess skin oxygen tension. Systolic and diastolic blood pressure were also assessed on both visits. We observed significant improvements in axon-mediated microvascular vasodilation for the younger group [1.6 (0.59) vs 2.05 (0.72), p<0.05] and the older group [1.25 (0.58) vs 1.65 (0.5) p<0.05]. Improvements in skin oxygen tension were also noted for both groups in both noted TcPO2 measures (i.e. 1.25 (0.58) vs 1.65 (0.5) (p<0.05), for ΔTcPO2max for the older group, between visits) respectively. Improvements were also observed for systolic blood pressure in both the younger [120 (10) vs 112 (10), p<0.05] and older group [129 (12) v 124 (11), p<0.001]. In conclusion, we observed statistically-significant improvements in microvascular function and skin oxygen tension. Our results suggest that green tea may prove beneficial as a dietary element in lifestyle interventions aiming to lower cardiovascular disease risk, in both older and younger populations.
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Effects of a high-intensity interval training program versus a moderate-intensity continuous training program on maximal oxygen uptake and blood pressure in healthy adults: study protocol for a randomized controlled trial.
Arboleda Serna, VH, Arango Vélez, EF, Gómez Arias, RD, Feito, Y
Trials. 2016;:413
Abstract
BACKGROUND Participation in aerobic exercise generates increased cardiorespiratory fitness, which results in a protective factor for cardiovascular disease and all-cause mortality. High-intensity interval training might cause higher increases in cardiorespiratory fitness in comparison with moderate-intensity continuous training; nevertheless, current evidence is not conclusive. To our knowledge, this is the first study to test the effect of high-intensity interval training with total load duration of 7.5 min per session. METHODS A randomized controlled trial will be performed on two groups of healthy, sedentary male volunteers (n = 44). The study protocol will include 24 exercise sessions, three times a week, including aerobic training on a treadmill and strength training exercises. The intervention group will perform 15 bouts of 30 s, each at an intensity between 90 % and 95 % of maximal heart rate. The control group will complete 40 min of continuous exercise, ranging between 65 % and 75 % of maximal heart rate. The primary outcome measure to be evaluated will be maximal oxygen uptake (VO2max), and systolic and diastolic blood pressure will be evaluated as secondary outcome measures. Waist circumference, body mass index, and body composition will also be evaluated. DISCUSSION Epidemiological evidence shows the link between VO2max and its association with chronic conditions that trigger CVD. Therefore, finding ways to improve VO2max and reduce blood pressure it is of vital importance to public health. TRIAL REGISTRATION NCT02288403 . Registered on 4 November 2014.
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Does the incremental shuttle walk test require maximal effort in young obese women?
Jürgensen, SP, Trimer, R, Di Thommazo-Luporini, L, Dourado, VZ, Bonjorno-Junior, JC, Oliveira, CR, Arena, R, Borghi-Silva, A
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas. 2016;(8)
Abstract
Obesity is a chronic disease with a multifaceted treatment approach that includes nutritional counseling, structured exercise training, and increased daily physical activity. Increased body mass elicits higher cardiovascular, ventilatory and metabolic demands to varying degrees during exercise. With functional capacity assessment, this variability can be evaluated so individualized guidance for exercise training and daily physical activity can be provided. The aim of the present study was to compare cardiovascular, ventilatory and metabolic responses obtained during a symptom-limited cardiopulmonary exercise test (CPX) on a treadmill to responses obtained by the incremental shuttle walk test (ISWT) in obese women and to propose a peak oxygen consumption (VO2) prediction equation through variables obtained during the ISWT. Forty obese women (BMI ≥30 kg/m2) performed one treadmill CPX and two ISWTs. Heart rate (HR), arterial blood pressure (ABP) and perceived exertion by the Borg scale were measured at rest, during each stage of the exercise protocol, and throughout the recovery period. The predicted maximal heart rate (HRmax) was calculated (210 - age in years) (16) and compared to the HR response during the CPX. Peak VO2 obtained during CPX correlated significantly (P<0.05) with ISWT peak VO2 (r=0.79) as well as ISWT distance (r=0.65). The predictive model for CPX peak VO2, using age and ISWT distance explained 67% of the variability. The current study indicates the ISWT may be used to predict aerobic capacity in obese women when CPX is not a viable option.
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l-Citrulline supplementation improves O2 uptake kinetics and high-intensity exercise performance in humans.
Bailey, SJ, Blackwell, JR, Lord, T, Vanhatalo, A, Winyard, PG, Jones, AM
Journal of applied physiology (Bethesda, Md. : 1985). 2015;(4):385-95
Abstract
The purpose of this study was to compare the effects of l-citrulline (Cit) and l-arginine (Arg) supplementation on nitric oxide (NO) biomarkers, pulmonary O2 uptake (V̇o2) kinetics, and exercise performance. In a randomized, placebo (Pla)-controlled, crossover study, 10 healthy adult men completed moderate- and severe-intensity cycling exercise on days 6 and 7 of a 7-day supplementation period with Pla, Arg (6 g/day), and Cit (6 g/day). Compared with Pla, plasma Arg concentration was increased by a similar magnitude with Arg and Cit supplementation, but plasma Cit concentration was only increased (P < 0.001) with Cit supplementation. Plasma nitrite (NO2 (-)) concentration was increased with Arg supplementation (P < 0.05) and tended to increase with Cit supplementation (P = 0.08) compared with Pla (83 ± 25, 106 ± 41, and 100 ± 38 nM with Pla, Arg, and Cit, respectively); however, mean arterial blood pressure was only lower (P < 0.05) after Cit supplementation. The steady-state V̇o2 amplitude during moderate-intensity cycle exercise was not significantly different between supplements, but Cit lowered the V̇o2 mean response time (59 ± 8 and 53 ± 5 s with Pla and Cit, respectively, P < 0.05) during severe-intensity exercise, improved tolerance to severe-intensity exercise (589 ± 101 and 661 ± 107 s with Pla and Cit, respectively), and increased the total amount of work completed in the exercise performance test (123 ± 18 and 125 ± 19 kJ with Pla and Cit, respectively, P < 0.05). These variables were not altered by Arg supplementation (P > 0.05). In conclusion, these results suggest that short-term Cit, but not Arg, supplementation can improve blood pressure, V̇o2 kinetics, and exercise performance in healthy adults.
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Higher-Intensity Exercise Results in More Sustainable Improvements for VO2peak for Breast and Prostate Cancer Survivors.
Martin, EA, Battaglini, CL, Hands, B, Naumann, F
Oncology nursing forum. 2015;(3):241-9
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PURPOSE/OBJECTIVES To examine peak volume of oxygen consumption (VO2peak) changes after a high- or low-intensity exercise intervention. DESIGN Experimental trial comparing two randomized intervention groups with control. SETTING An exercise clinic at a university in Australia. SAMPLE 87 prostate cancer survivors (aged 47-80 years) and 72 breast cancer survivors (aged 34-76 years). METHODS Participants enrolled in an eight-week exercise intervention (n = 84) or control (n = 75) group. Intervention participants were randomized to low-intensity (n = 44, 60%-65% VO2peak, 50%-65% of one repetition maximum [1RM]) or high-intensity (n = 40, 75%-80% VO2peak, 65%-80% 1RM) exercise groups. Participants in the control group continued usual routines. All participants were assessed at weeks 1 and 10. The intervention groups were reassessed four months postintervention for sustainability. MAIN RESEARCH VARIABLES VO2peak and self-reported physical activity. FINDINGS Intervention groups improved VO2peak similarly (p = 0.083), and both more than controls (p < 0.001). The high-intensity group maintained VO2peak at follow-up, whereas the low-intensity group regressed (p = 0.021). The low-intensity group minimally changed from baseline to follow-up by 0.5 ml/kg per minute, whereas the high-intensity group significantly improved by 2.2 ml/kg per minute (p = 0.01). Intervention groups always reported similar physical activity levels. CONCLUSIONS Higher-intensity exercise provided more sustainable cardiorespiratory benefits than lower-intensity exercise. IMPLICATIONS FOR NURSING Survivors need guidance on exercise intensity, because a high volume of low-intensity exercise may not provide sustained health benefits.