Subpopulations of regulatory T cells are associated with subclinical atherosclerotic plaques,levels of LDL,and cardiorespiratory fitness in the elderly

Background:Atherosclerosis forms the pathological basis for the development of cardiovascular disease.Since pathological processes initially develop without clinically relevant symptoms,the identification of early markers in the subclinical stage plays an important role for initiating early interventions.There is evidence that regulatory T cells(Tregs)are involved in the development of atherosclerosis.Therefore,the present study aimed to identify and investigate associations with Tregs and their subsets in a cohort of healthy elderly individuals with and without subclinical atherosclerotic plaques(SAP).In addition,various lifestyle and risk factors,such as cardiorespiratory fitness,were investigated as associated signatures.Methods:A cross-sectional study was performed in 79 participants(male:n=50;age=63.6±3.7 years;body mass index=24.9±3.1 kg/m2;mean±SD)who had no previous diagnosis of chronic disease and were not taking medication.Ultrasound of the carotids to identify SAP,cardiovascular function measurement for vascular assessment and a cardiorespiratory fitness test to determine peak oxygen uptake were performed.Additionally,tests were conducted to assess blood lipids and determine glucose levels.Immunophenotyping of Tregs and their subtypes(resting(rTregs)and effector/memory(mTregs))was performed by 8-chanel flow cytometry.Participants were categorized according to atherosclerotic plaque status.Linear and logistic regression models were used to analyze associations between parameters.Results:SAP was detected in a total of 29 participants.The participants with plaque were older(64.8±3.6 years vs.62.9±3.5 years)and had higher peripheral systolic blood pressure(133.8±14.7 mmHg vs.125.8±10.9 mmHg).The participants with SAP were characterized by a lower percentage of rTregs(28.8%±10.7%vs.34.6%±10.7%)and a higher percentage of mTregs(40.3%±14.7%vs.30.0%±11.9%).Multiple logistic regression identified age(odds ratio(OR)=1.20(95%confidence interval(95%CI):1.011.42))and mTregs(OR=1.05(95%CI:1.021.10))as independent risk factors for SAP.Stepwise linear regression could reveal an association of peak oxygen uptake(β=0.441),low-density lipoprotein(LDL)(β=0.096),and SAP(β=6.733)with mTregs and LDL(β=0.104)with rTregs.Conclusion:While at an early stage of SAP,the total proportion of Tregs gives no indication of vascular changes,this is indicated by a shift in the Treg subgroups.Factors such as serum LDL or cardiopulmonary fitness may be associated with this shift and may also be additional diagnostic indicators.This could be used to initiate lifestyle-based preventive measures at an early stage,which may have a protective effect against disease progression.

Association between cardiorespiratory fitness level and insulin resistance in adolescents with various obesity categories

BACKGROUND An association between cardiorespiratory fitness(CRF)and insulin resistance in obese adolescents,especially in those with various obesity categories,has not been systematically studied.There is a lack of knowledge about the effects of CRF on insulin resistance in severely obese adolescents,despite their continuous rise.AIM To investigate the association between CRF and insulin resistance in obese adolescents,with special emphasis on severely obese adolescents.METHODS We performed a prospective,cross-sectional study that included 200 pubertal adolescents,10 years to 18 years of age,who were referred to a tertiary care center due to obesity.According to body mass index(BMI),adolescents were classified as mildly obese(BMI 100% to 120% of the 95^(th)percentile for age and sex)or severely obese(BMI≥120% of the 95^(th)percentile for age and sex or≥35 kg/m^(2),whichever was lower).Participant body composition was assessed by bioelectrical impedance analysis.A homeostatic model assessment of insulin resistance(HOMA-IR)was calculated.Maximal oxygen uptake(VO_(2)max)was determined from submaximal treadmill exercise test.CRF was expressed as VO_(2)max scaled by total body weight(TBW)(mL/min/kg TBW)or by fat free mass(FFM)(mL/min/kg FFM),and then categorized as poor,intermediate,or good,according to VO_(2)max terciles.Data were analyzed by statistical software package SPSS(IBM SPSS Statistics for Windows,Version 24.0).P<0.05 was considered statistically significant.RESULTS A weak negative correlation between CRF and HOMA-IR was found[Spearman’s rank correlation coefficient(rs)=-0.28,P<0.01 for CRF_(TBW);(r_(s))=-0.21,P<0.01 for CRF_(FFM)].One-way analysis of variance(ANOVA)revealed a significant main effect of CRF on HOMA-IR[F(2200)=6.840,P=0.001 for CRF_(TBW);F_((2200))=3.883,P=0.022 for CRF_(FFM)].Subsequent analyses showed that obese adolescents with poor CRF had higher HOMA-IR than obese adolescents with good CRF(P=0.001 for CRF_(TBW);P=0.018 for CRF_(FFM)).Two-way ANOVA with Bonferroni correction confirmed significant effect of interaction of CRF level and obesity category on HOMA-IR[F_((2200))=3.292,P=0.039 for CRF_(TBW)].Severely obese adolescents had higher HOMA-IR than those who were mildly obese,with either good or poor CRF.However,HOMA-IR did not differ between severely obese adolescents with good and mildly obese adolescents with poor CRF.CONCLUSION CRF is an important determinant of insulin resistance in obese adolescents,regardless of obesity category.Therefore,CRF assessment should be a part of diagnostic procedure,and its improvement should be a therapeutic goal.

Comparison of the effects of high-intensity interval and moderate-intensity continuous training on inflammatory markers,cardiorespiratory fitness,and quality of life in breast cancer patients

Background:As the effectiveness of breast cancer treatment has improved,a growing number of long-term breast cancer survivors are seeking help for unique health problems.These patients may be at increased risk of cardiovascular disease due to the side effects of treatment.The positive impact of most types of exercise has been repeatedly reported in people with cancer,but the most effective exercise approaches for maximum beneficial adaptations remain controversial.Thus,this study aimed to compare the effects of high-intensity interval training(HIIT)and moderate-intensity continuous training(MICT) on inflammatory indices,adipokines,metabolic markers,body composition,cardiorespiratory fitness,and quality of life in breast cancer patients during adjuvant endocrine therapy.Methods:Thirty non-metastatic breast cancer patients during adjuvant endocrine therapy who had been treated with chemotherapy and/or radiotherapy were recruited from Iran and randomized to HIIT,MICT,or control groups for a supervised exercise intervention that took place 3 times a week for 12 weeks.The training intensity was determed based on the peak oxygen uptake(VO2peak),and the volume of training was matched in HIIT and MICT based on the VO2peak.Body composition,functional capacity,cardiorespiratory fitness,metabolic indices,sex hormones,adipokines,and inflammatory markers were assessed before and after the intervention.Results:The VO2peakincreased by 16.8% in the HIIT group in comparison to baseline values(mean difference=3.61 mL/kg/min).HIIT significantly improved the VO2peakcompared to control(mean difference=3.609 mL/kg/min) and MICT(mean differences=2.974 mL/kg/min)groups.Both HIIT(mean difference=9.172 mg/dL) and MICT(mean difference=7.879 mg/dL) interventions significantly increased highdensity lipoprotein cholesterol levels compared to the control group.The analysis of covariance showed that physical well-being significantly improved in MICT compared to control group(mean difference=3.268).HIIT significantly improved the social well-being compared to the control group(mean difference=4.412).Emotional well-being subscale was significantly improved in both MICT(mean difference=4.248)and HIIT(mean difference=4.412) compared to the control group.Functional well-being scores significantly increased in HIIT group compared with control group(mean difference=3.35).Significant increase were also observed in total functional assessment of cancer therapy-General scores in both HIIT(mean difference=14.204) and MICT groups(mean difference=10.036) compared with control group.The serum level of suppressor of cytokine signaling 3 increased significantly(mean difference=0.09 pg/mL) in the HIIT group compared to the baseline.There were no significant differences between groups for body weight,body mass index,fasting blood glucose,insulin resistance,sex hormone binding globulin,total cholesterol,low-density lipoprotein cholesterol,adipokines,interleukin-6,tumor necrosis factor-a,or interleukin-10.Conclusion:HIIT can be used as a safe,feasible,and time-efficient intervention to improve cardiovascular fitness in breast cancer patients.Both HIIT and MICT modalities enhance quality of life.Further large-scale studies will help determine whether these promising results translate into improved clinical and oncological outcomes.

Effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in type 2 diabetes:A systematic review

BACKGROUND Type 2 diabetes mellitus(T2DM)is a chronic metabolic syndrome characterized by insulin resistance and hyperglycemia that may lead to endothelial dysfunction,reduced functional capacity and exercise intolerance.Regular aerobic exercise has been promoted as the most beneficial non-pharmacological treatment of cardiovascular diseases.High intensity interval training(HIIT)seems to be superior than moderate-intensity continuous training(MICT)in cardiovascular diseases by improving brachial artery flow-mediated dilation(FMD)and cardiorespiratory fitness to a greater extent.However,the beneficial effects of HIIT in patients with T2DM still remain under investigation and number of studies is limited.AIM To evaluate the effectiveness of high intensity interval training on cardiorespiratory fitness and endothelial function in patients with T2DM.METHODS We performed a search on PubMed,PEDro and CINAHL databases,selecting papers published between December 2012 and December 2022 and identified published randomized controlled trials(RCTs)in the English language that included community or outpatient exercise training programs in patients with T2DM.RCTs were assessed for methodological rigor and risk of bias via the Physiotherapy Evidence Database(PEDro).The primary outcome was peak VO_(2 ) and the secondary outcome was endothelial function assessed either by FMD or other indices of microcirculation.RESULTS Twelve studies were included in our systematic review.The 12 RCTs resulted in 661 participants in total.HIIT was performed in 310 patients(46.8%),MICT to 271 and the rest 80 belonged to the control group.Peak VO_(2 ) increased in 10 out of 12 studies after HIIT.Ten studies compared HIIT with other exercise regimens(MICT or strength endurance)and 4 of them demonstrated additional beneficial effects of HIIT over MICT or other exercise regimens.Moreover,4 studies explored the effects of HIIT on endothelial function and FMD in T2DM patients.In 2 of them,HIIT further improved endothelial function compared to MICT and/or the control group while in the rest 2 studies no differences between HIIT and MICT were observed.CONCLUSION Regular aerobic exercise training has beneficial effects on cardiorespiratory fitness and endothelial function in T2DM patients.HIIT may be superior by improving these parameters to a greater extent than MICT.

Fatigability during volitional walking in incomplete spinal cord injury: cardiorespiratory and motor performance considerations

Fatigability describes the decline in force production（i.e., performance fatigability） and/or changes in sensations regulating performance（i.e., perceived fatigability） during whole-body activity and poses a major challenge to those living with spinal cord injuries（SCI）. After SCI, the inability to overcome disruptions to metabolic homeostasis due to cardiorespiratory limitations and physical deconditioning may contribute to increased fatigability severity. The increased susceptibility to fatigability may have implications for motor control strategies and motor learning. Locomotor training approaches designed to reduce fatigability and enhance aerobic capacity in combination with motor learning may be advantageous for promoting functional recovery after SCI. Future research is required to advance the understanding of the relationship between fatigability, cardiorespiratory function and motor performance following SCI.

Rationale and design of the cardiorespiratory fitness and hospitalization events in armed forces study in Eastern Taiwan

AIM To investigate the association between cardiorespiratory fitness and hospitalization events in a cohort of large voluntary arm forces in Taiwan. METHODS The cardiorespiratory fitness and hospitalization events in armed forces(CHIEF) is a retrospective cohort consisting of more than 4000 professional military members aged 18-50 years in Eastern Taiwan. All participants received history taking, physical examination, chest radiography, 12-lead electrocardiography, blood tests for cell counts and fasting glucose, lipid profiles, uric acid, renal function and liver function in the Hualien Armed Forces General Hospital during 2014. In addition, participants were required to undergo two indoor resistant exercise tests including 2-min push-up and 2-min sit-up, both scored by infrared sensing, and one outdoor endurance 3000-m none weight-bearing running test, the main indicator of cardiorespiratory fitness in the Military Physical Training and Testing Center in Eastern Taiwan in 2014. RESULTS Hospitalization events for cardiovascular disease, acute kidney injury, rhabdomyolysis, severe infectious disease, acute psychiatric illness, diabetes, orthopedic surgery and mortality will be identified in the National Insurance Research Database for 10 years. CONCLUSION CHIEF will be among the largest Eastern Asian armed forces cohort, in which physical status was strictly evaluated to follow up the hospitalization events for severe illness.

Effects of glucose-lowering agents on cardiorespiratory fitness

Exercise therapy is essential for the management of type 2 diabetes(T2 D). However, patients with T2 D show lower physical activity and reduced cardiorespiratory fitness than healthy individuals. It would be ideal for clinicians to co-prescribe glucose-lowering agents that improve cardiorespiratory fitness or exercise capacity in conjunction with exercise therapy. Metformin does not improve cardiorespiratory fitness and may attenuate any beneficial effect of exercise in patients with T2 D. In contrast, thiazolidinediones appear to improve cardiorespiratory fitness in patients with T2 D. Although evidence is limited, sodium–glucose cotransporter 2(SGLT2) inhibitors may improve cardiorespiratory fitness in patients with heart failure, and the effect of glucagon-like peptide-1(GLP-1) receptor agonists on cardiorespiratory fitness is controversial. Recent clinical trials have shown that both SGLT2 inhibitors and GLP-1 receptor agonists exert a favorable effect on cardiovascular disease. It becomes more important to choose drugs that have beneficial effects on the cardiovascular system beyond glucose-lowering effects. Further studies are warranted to determine an ideal glucose-lowering agent combined with exercise therapy for the treatment of T2 D.

Effect of Exercise-Based Cardiac Rehabilitation on Cardiorespiratory Fitness in Adults with Congenital Heart Disease

Background:The purpose of this study was to investigate whether patients with adult congenital heart disease(ACHD)benefit from exercise-based cardiac rehabilitation(CR)short-and long-term with regard to improvement of cardiorespiratory fitness.Methods:Cardiopulmonary exercise tests(CPET)completed by ACHD patients between January 2000 and October 2019 were analysed retrospectively.Linear mixed models were performed for peak oxygen consumption(VO_(2))with patients as random effect and age,sex,disease classification,preceding surgery(≤3 months)and preceding CR(≤4 weeks for short term and>4 weeks for long term)as fixed effects.Results:1056 CPETs of 311 ACHD patients with simple(7),moderate(188)or great(116)complexity heart defects were analysed.The 59 patients who completed a CR(median age 27 yrs,38%females)increased peak VO_(2)from before to after CR by a median of 2.7(IQR–0.6 to 5.5)ml/kg/min.However,in the multivariate mixed model,peak VO_(2)was non-significantly increased short-term after CR(β0.8,95%CI–0.7 to 2.4),not maintained long-term after CR(β0.0,95%CI–1.7 to 1.6)but significantly reduced after surgery(β–5.1,95%CI–7.1 to–3.1).The 20 CR patients after surgery increased their peak VO_(2)by 6.2(IQR 3.6–9.5)ml/kg/min,while the 39 CR patients without preceding surgery increased it by 0.9(IQR–1.5 to 3.1)ml/kg/min.Conclusions:The increase in peak VO_(2)with CR was mainly due to recovery from surgical intervention.The small independent benefit from CR was not maintained long-term,highlighting the potential to improve current CR concepts in ACHD populations.

Can a cardiorespiratory field parameter assess both cardiovascular and respiratory fitness in schoolchildren?

Background: Cardiorespiratory fitness involves both cardiovascular and respiratory capacities. However, existing methods have been criticised for reflecting cardiovascular fitness, but not pulmonary fitness. The objective of this study was to investigate the relationship between these two testing parameters. Methods: A cross-sectional population-based physical fitness assessment was conducted in 23 schools. The body height and weight, lung capacity, and step test results of students aged 10-18 were recorded. Criterion-referenced standards from the China Sports Bureau were adopted, as they include separate measurements for cardiovascular and pulmonary fitness. Results: The Pearson coefficients of lung capacity and the step test index from 13,028 schoolchildren ranged from 0.007 to 0.086 and from 0.026 to 0.105 for boys and girls, respectively, showing that poor correlations exist between the two parameters. Cluster analysis resulted in three clusters of children with similar characteristics. A good degree of similarity was found between the two parameters in children obtaining an “excellent” grade, but only a moderate degree of similarity between the two parameters in those obtaining a “good”, “pass” or “fail” grade. Conclusion: When cardiovascular fitness and pulmonary fitness are considered separately, there is a poor correlation between them, thus indicating further studies of cardiopulmonary fitness measurements is necessary.

Analyzing Spatial Patterns of Cardiorespiratory Diseases in the Federal District, Brazil

Cardiorespiratory diseases are a serious public health problem worldwide. Identification of spatial patterns in health events is an efficient tool to guide public policies in environmental health. However, only few studies have considered spatial pattern analysis which is considered the evaluation of spatial autocorrelation, degree of autocorrelation and dependence behavior in terms of distances. Therefore, the objective of this study is to propose a set of procedures to evaluate the spatial patterns of cardiorespiratory diseases in the Federal District, Brazil. Specifically, our proposal will be based on four questions: a) is the spatial distribution of all patients clustered, random or dispersed? b) what is the degree of clustering for either high values or low values of patients? c) what is the spatial dependence behavior? d) considering the spatial variation, at what distance does the type of distribution (cluster, random or disperse) begin to change? We chose four methods to answer these questions Global Moran’s I (question “a”);Getis-Ord General G (question “b”);semivariogram analysis (question “c”);and multi-distance spatial cluster-K-function (question “d”). Our results suggest that there is a different behavior for people up to 5 years old (cluster, p < 0.01), especially in distances below 2.5 km. For people above 59 years old, cluster is significant just in short distances (<200 m). For other age groups, the spatial distribution is basically random. Our study showed that it was possible to capture evidences of health disparities in the Federal District.

Effects of Judo Strength-Velocity Training during Precompetition on Cardiorespiratory Responses in Congolese Judoists Aged 15 - 17 Years Old

Objective: To evaluate the effects of “strength-velocity” training on the evolution of some cardiorespiratory parameters in postpubertal judoists of the Congolese national elite. Methods: The survey, exploratory, experimental and longitudinal, was about 14 boys, belonging to seven categories of weight of the International Federation of Judo. These judoists, at the level belonged to stages 3, 4 and 5 of the classification to Tanner, of pubertal maturation. Their median age was 16 years (range: 15 - 17 years). All topics have been submitted to “strength-velocity” training, focused around exercises bound to the development of the power and automatisms, from plyometric and isometric training. Three assessments have been realized in the beginning, to mid-training (3 months) and at the end of the program (6 months). The measured values were cardiorespiratory parameters. Results: The heart rate to the doorstep was decreased significantly (p = 0.048), so VO2 max (p = 0.046), FVC (p = 0.0244) and ratio VEMS/FVC (p = 0.046) as function of pubertal stage. In contrast, increase was not significant for VEMS (p = 0.205) and absolute VO2 to doorstep (p = 0.097). No significant effect of pubertal state on respiratory frequency was found. On the other hand, strength-velocity training improved cardiorespiratory data. To the recovery of the “strength-velocity test”, the decrease of the VO2 took place more quickly that the one of the VE, the VCO2 and the HR, variations linked to the category of topic weight. Conclusion: Among high level Congolese postpubertal judoists, the cardiorespiratory modifications induce faculty to the realization of a good performance and pursue objectives of health. However, it is necessary to be heedful as for situations to put in place in sittings at the time of such of “strength-velocity” training.

Influence of cardiorespiratory fitness and body composition on resting and post-exercise indices of vascular health in young adults

Poor cardiorespiratory fitness may mediate vascular impairments at rest and following an acute bout of exercise in young healthy individuals.This study aimed to compare flow mediated dilation(FMD)and vascular augmentation index(AIx75)between young adults with low,moderate,and high levels of cardiorespiratory fitness before and after an acute bout of aerobic exercise.Forty-three participants(22 men;21 women)between 18 and 29 years of age completed the study.Participants were classified into low,moderate,and high health-related cardiorespiratory fitness groups according to age-and sex-based relative maximal oxygen consumption(V_O2 max)percentile rankings.FMD was performed using Doppler ultrasound and AIx75 was performed using pulse wave analysis at baseline and 60-min after a 30-min bout of treadmill running at 70%V_O2 max.A significant interaction(p=0.047;ηp 2=0.142)was observed,with the moderate fitness group exhibiting a higher FMD post-exercise compared with baseline([6.7%3.1%]vs.[8.5%2.8%],p=0.028;d=0.598).We found a significant main effect of group for AIx75(p=0.023;ηp 2=0.168),with the high fitness group exhibiting lower AIx75 compared to low fitness group([10%10%]vs.[2%10%],respectively,p=0.019;g=1.07).This was eliminated after covarying for body fat percentage(p=0.489).Our findings suggest that resting FMD and AIx75 responses are not significantly influenced by cardiorespiratory fitness,but FMD recovery responses to exercise may be enhanced in individuals with moderate cardiorespiratory fitness levels.

Associations between health-related fitness and patient-reported symptoms in newly diagnosed breast cancer patients

Background:Newly diagnosed breast cancer patients experience symptoms that may affect their quality of life,treatment outcomes,and survival.Preventing and managing breast cancer-related symptoms soon after diagnosis is essential.The purpose of this study was to investigate the associations between health-related fitness(HRF)and patient-reported symptoms in newly diagnosed breast cancer patients.Methods:This study utilized baseline data from the Alberta Moving Beyond Breast Cancer Cohort Study that were collected within 90 days of diagnosis.HRF measures included peak cardiopulmonary fitness(peak volume of oxygen consumption(VO_(2peak))),maximal muscular strength and endurance,flexibility,and body composition.Symptom measures included depression,sleep quality,and fatigue.Adjusted multivariable logistic regression was performed for analyses.Results:Of 1458 participants,51.5%reported poor sleep quality,26.5%reported significant fatigue,and 10.4%reported moderate depression.In multivariable-adjusted models,lower relative VO_(2peak)was independently associated with a greater likelihood of all symptom measures,including moderate depression(p<0.001),poor sleep quality(p=0.009),significant fatigue(p=0.008),any symptom(p<0.001),and multiple symptoms(p<0.001).VO_(2peak)demonstrated threshold associations with all symptom measures such that all 3 lower quartiles exhibited similar elevated risk compared to the highest quartile.The strength of the threshold associations varied by the symptom measure with odds ratios ranging from-1.5 for poor sleep quality to-3.0 for moderate depression and multiple symptoms.Moreover,lower relative upper body muscular endurance was also independently associated with fatigue in a dose-response manner(p=0.001),and higher body weight was independently associated with poor sleep quality in an inverted U pattern(p=0.021).Conclusion:Relative VO_(2peak)appears to be a critical HRF component associated with multiple patient-reported symptoms in newly diagnosed breast cancer patients.Other HRF parameters may also be important for specific symptoms.Exercise interventions targeting different HRF components may help newly diagnosed breast cancer patients manage specific symptoms and improve outcomes.

Effects of a school-based karate intervention on academic achievement,psychosocial functioning,and physical fitness:A multi-country cluster randomized controlled trial

Purpose:To examine the effects of a school-based karate intervention on academic achievement,psychosocial functioning,and physical fitness in children aged 7-8 years.Methods:Twenty schools in 5 different European countries(2 second-grade classrooms per school)participated in a cluster randomized controlled trial(Sport at School trial).Participants were assigned to either a control group,which continued with their habitual physical education lessons,or to an intervention group,which replaced these lessons with a 1-year karate intervention(Karate Mind and Movement program).A total of 721 children(344 girls and 377 boys,7.4±0.5 years old,mean±SD)completed the study,of which 333 and 388 were assigned to the control group and intervention group,respectively.Outcomes included academic performance(average grade),psychosocial functioning(Strengths and Difficulties Questionnaire for parents),and different markers of physical fitness(cardiorespiratory fitness,balance,and flexibility).Results:The intervention provided small but significant benefits compared to the control group for academic achievement(d=0.16;p=0.003),conduct problems(d=-0.28;p=0.003),cardiorespiratory fitness(d=0.36;p<0.001),and balance(d=0.24;p=0.015).There was a trend towards significant benefits for flexibility(d=0.24;p=0.056).No significant benefits were observed for other variables,including psychosocial difficulties,emotional symptoms,hyperactivity/inattention,peer problems,or prosocial behaviour(all p>0.05).Conclusion:A 1-year school-based karate intervention was effective in improving academic achievement,conduct problems,and physical fitness in primary school children.The results support the inclusion of karate during physical education lessons.

Association between baseline levels of muscular strength and risk of stroke in later life:The Cooper Center Longitudinal Study

Background:Muscular strength is an important component of physical fitness.We evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged≥65 years during follow-up.Methods:We included 7627 healthy adults(mean age=43.9 years,86.0%male)underwent a baseline physical examination between 1980 and 1989.Muscular strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age-and sex-specific tertiles for each measure.Cardiorespiratory fitness(CRF)was assessed via a maximal treadmill exercise test.Those enrolled in fee-for-service Medicare from 1999 to 2019 were included in the analyses.Associations between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards model.In a secondary analysis,we examined stroke risk by categories of CRF where Quintile 1=low,Quintiles 2-3=moderate,and Quintiles 4-5=high CRF based on age and sex.Results:After 70,072 person-years of Medicare follow-up,there were 1211 earliest indications of incident stroke.In multivariable analyses,the hazard ratio(95%confidence interval(95%CI))for stroke across bench press categories were 1.0(referent),0.96(0.83-1.11),and 0.89(0.77-1.04),respectively(p trend=0.14).The trend across categories of leg press was also non-significant(p trend=0.79).Adjusted hazard ratio(95%CI)for stroke across ordered CRF categories were 1.0(referent),0.90(0.71-1.13),and 0.72(0.57-0.92)(p trend<0.01).Conclusion:While meeting public health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults,performing such activities may not be helpful in preventing stroke.Conversely,meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

Development,validation,and transportability of several machine-learned,non-exercise-based VO_(2max)prediction models for older adults

Background:There exist few maximal oxygen uptake(VO_(2max))non-exercise-based prediction equations,fewer using machine learning(ML),and none specifically for older adults.Since direct measurement of VO_(2max)is infeasible in large epidemiologic cohort studies,we sought to develop,validate,compare,and assess the transportability of several ML VO_(2max)prediction algorithms.Methods:The Baltimore Longitudinal Study of Aging(BLSA)participants with valid VO2_(max)tests were included(n=1080).Least absolute shrinkage and selection operator,linear-and tree-boosted extreme gradient boosting,random forest,and support vector machine(SVM)algorithms were trained to predict VO_(2max)values.We developed these algorithms for:(a)the overall BLSA,(b)by sex,(c)using all BLSA variables,and(d)variables common in aging cohorts.Finally,we quantified the associations between measured and predicted VO_(2max)and mortality.Results:The age was 69.0±10.4 years(mean±SD)and the measured VO_(2max)was 21.6±5.9 mL/kg/min.Least absolute shrinkage and selection operator,linear-and tree-boosted extreme gradient boosting,random forest,and support vector machine yielded root mean squared errors of 3.4 mL/kg/min,3.6 mL/kg/min,3.4 mL/kg/min,3.6 mL/kg/min,and 3.5 mL/kg/min,respectively.Incremental quartiles of measured VO_(2max)showed an inverse gradient in mortality risk.Predicted VO_(2max)variables yielded similar effect estimates but were not robust to adjustment.Conclusion:Measured VO_(2max)is a strong predictor of mortality.Using ML can improve the accuracy of prediction as compared to simpler approaches but estimates of association with mortality remain sensitive to adjustment.Future studies should seek to reproduce these results so that VO_(2max),an important vital sign,can be more broadly studied as a modifiable target for promoting functional resiliency and healthy aging.

Cardiorespiratory Effects of Indoor Ozone Exposure Associated with Changes in Metabolic Profiles among Children:A Repeated-Measure Panel Study

Ozone is one of the major gaseous pollutants associated with short-term adverse cardiopulmonary effects,even at concentrations below the current indoor air quality limits.However,the underlying biological mechanisms of cardiorespiratory changes with exposure to ozone remain unclear.To further explore molecular linkages between indoor ozone exposure and relevant cardiorespiratory effects,a repeated-measure panel study including 46 schoolchildren was conducted and real-time exposure measurements including ozone were performed inside classrooms every weekday during the study period.Repeated health measurements and urine sample collection were conducted in each participant.Ultra-high-performance liquid chromatography/tandem mass spectrometry and meet-in-metabolite approach were used in metabolomics analysis.Methods including mixed-effect models were adopted to identify metabolites associated with ozone exposure or health indices.Nine metabolites were found to be associated with ozone after mixed-effect model analysis,which are mainly involved in amino acid and bile acid metabolism.Boys may have a greater decrease in bile acid and RNA related metabolites.Four of the nine ozone-related metabolites were also associated with cardiorespiratory function indices.Furthermore,26.67%of the positive association between ozone and heart rate was mediated by cholestane-3,7,12,25-tetrol-3-glucuronide.Exposure to ozone below the current indoor standards was associated with the deteriorated cardiovascular function by disturbing bile acid and endogenous nitric oxide-related oxidation and inflammation,and associated with the exacerbated airway inflammation by reducing GPx-related anti-oxidation.The results provide metabolic evidence of the cardiorespiratory effects of indoor ozone exposure.Indoor ozone pollution should be controlled further,and more attention should be paid to preventing its adverse health effects,especially in children.

Is BMI Associated with Cardiorespiratory Fitness?A Cross-Sectional Analysis Among 8470 Apparently Healthy Subjects Aged 18-94 Years from the Low-Lands Fitness Registry

Objective The purpose of the present study was to investigate the association between cardiorespiratory fitness(CRF)measured as peak oxygen uptake(VO_(2peak),expressed in mL/min)and body mass index(BMI)in a large cohort of apparently healthy subjects.Methods BMI and VO_(2peak)were measured in a cross-sectional study of 8470 apparently healthy adults.VO_(2peak)(mL/min)was determined by an incremental cycle ergometer test to exhaustion.Linear regression analyses were performed to identify predictors of CRF.Results There was no difference in CRF between adults with a normal weight(BMI between 18.5-24.9 kg/m^(2))and those who were overweight(BMI 25.0-29.9 kg/m^(2)).Subjects who were underweight(BMI<18.5 kg/m^(2))as well as females who were obese(BMI≥30.0 kg/m^(2))showed a reduced CRF compared to the normal and overweight groups.Age,height,and gender were significant predictors of CRF(R^(2)=0.467,P<0.0001);BMI did not add significantly to this relationship.Conclusion Our findings indicate that BMI was not associated with CRF in addition to age,height,and gender.In subjects with a BMI<18.5 kg/m^(2),CRF was lower compared to subjects with a BMI between 18.5 and 29.9 kg/m^(2).In obese subjects,CRF was only lower in females compared to females with a BMI between 18.5 and 29.9 kg/m^(2).Correcting CRF for BMI may be beneficial for subjects with a low BMI,and females with a BMI≥30.0 kg/m^(2).The outcome of this study might help to improve the interpretation of exercise testing results in individuals with a low or high BMI.

Effects of whole body vibration training on cardiorespiratory fitness and quality of life in patients with subacute stroke:A randomized controlled trial

Background Cardiorespiratory fitness reduction is potentially related to function/structure,and activity of the stroke patients may be associated with increased risk of cardiovascular disease. Whole body vibration（WBV）training is an efficient alternative therapy for neurological conditions. However,no study has investigated the effects of WBV training on cardiorespiratory fitness in patients with subacute stroke. This single-blinded randomized controlled trial was conducted to assess the effects WBV training on cardiorespiratory fitness and quality of life in individuals with subacute stroke. Methods Thirty-three people with subacute stroke（66.56±5.25 years）were enrolled from 87 patients initially screened（25 patients were excluded by inclusion/exclusion criteria,13 patients for other reasons,16 patients declined participation）. Participants were randomly assigned to the low-intensity WBV group（LWBV）,high-intensity WBV group（HWBV）and a control group（No WBV）.All participants of low-and high-intensity WBV group were exercised on a vibration platform,and the control group performed the same exercise without WBV. Outcome measurements included oxygen uptake（VO2）rate and walking distance during the 6-Minute Walk Test（6 MWT）,and quality of life（Short-Form 12 Health Survey,SF-12）. The measurements were performed by a researcher at baseline and immediately after the 8-week WBV intervention period. Results Statistical analysis revealed a significant time effect for VO2 rate and walking distance achieved during 6 MWT,and the SF-12 physical composite score domain in all three groups after the 8-week treatment period（P<0.05）. However,the effects of time by group interactions were not significant for any of the VO2 and walking distance during 6 MWT,and quality of life（P>0.05）. Conclusions The addition of the 8-week WBV program to the leg exercise protocol is not more effective in enhancing cardiorespiratory fitness and quality of life than leg exercises alone in subacute stroke patients with mild to moderate motor impairments.[S Chin J Cardiol 2019;20（3）:131-140]

Prevalence of physical fitness in Chinese school-aged children： Findings from the 2016 Physical Activity and Fitness in China -The Youth Study

Purpose： This study was to present the 2016 prevalence estimates of Chinese school-aged children meeting physical fitness standards and to examine differences by sex and residence locales in children who did not meet fitness standards. Methods： We conducted cross-sectional analyses of 171,991 children and adolescents （boy： 50.0%, Grades 1-12） who participated in the 2016 Physical Activity and Fitness in China--The Youth Study. The main outcomes were fitness measures, assessed by the 2014 revised Chinese National Student Physical Fitness Standard （CNSPFS）, covering areas of aerobic capacity, upper body strength, flexibility, body mass index, abdominal strength, and trunk strength. Children＇s overall physical fitness performance was categorized, per CNSPFS standards, as excellent, good, pass, or no pass. Data on the prevalence of physical fitness categories and not meeting fitness standards （i.e., among children who received a ＂no pass＂ mark） were analyzed, through logistic regression, by sex （boy, girl） and residence locales （urban, rural） across 3 school grades （primary, junior middle, and junior high）. Results： In 2016, 5.95% of Chinese children and adolescents achieved an ＂excellent＂ mark, 25.80% received a ＂good＂ rating, 59.90% received a ＂pass＂, and 8.35% received a ＂no pass＂. Overall, boys were more likely to not pass the fitness standards compared with girls （adjusted odds ratio （aOR） = 1.710; 95% confidence interval （CI）： 1.708-1.712） and children living in urban areas were more likely to not pass the standards than those living in rural areas （aOR = 1.298; 95%CI： 1.296-1.299）. Consistent patterns of not meeting fitness standards were also found by sex and residence locales across all 3 school grades. Conclusion： In the Chinese school-aged population, about 3 in 10 children achieved an ＂excellent＂ or ＂good＂ fitness standard in 2016, and about 8% of this population did not meet CNSPFS standards. Children living in urban areas were more likely to not meet minimum fitness performance levels, and boys in school were more likely to not meet minimum fitness performance levels than girls. 2017 Production and hosting by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.