Cardiorespiratory fitness as predictor of cancer mortality: a systematic review and meta-analysis

Effects of home-based exercise with telehealth guidance in lymphoma cancer survivors entering cardio-oncology rehabilitation: rationale and design of the tele@home study

BACKGROUND

Participation in cardio-oncological rehabilitation is low, and the effects incline to decrease after the initial rehabilitation term. Home-based exercise has the potential to enhance involvement in cardio-oncology rehabilitation and was demonstrated to be feasible, safe, and helpful in increasing short-term cardiorespiratory fitness. The lasting effects on cardiorespiratory fitness and physical activity are uncertain. Hence, a novel approach via telehealth management based on objectively measured exercise at home was proposed.

OBJECTIVES

To improve self-monitoring, such as self-confidence, behavioral change, and goal setting for individual exercise, and afterward, increase long-term effects concerning cardiorespiratory fitness.

DESIGN

This randomized controlled trial compares a 12-week guided home exercise telehealth intervention with a center-based exercise intervention of the same duration and intensity of exercise in lymphoma cancer survivors entering cardio-oncology rehabilitation after treatment. Participants will be instructed to exercise gradually at 60-85% of their maximum heart rate for 30-50 min 3 times a week. Participants will receive individual remote guidance (feedback about frequency, duration, and exercise intensity) by preferred contact (phone call, text message) once a week based on shared exercise data through the web platform. The primary outcome is a change in cardiorespiratory fitness expressed as maximal oxygen uptake assessed through cardiopulmonary exercise test at baseline, 12 weeks, and 1 year. Secondary objectives are quality of life, muscle strength, body composition, incidence of adverse events, and exercise adherence. This study will determine whether a telehealth model is effective and safe compared to a center-based model in cancer survivors and whether exercise prescriptions are followed by participants. Additionally, an overview of the long-term effectiveness of telehealth cardio-oncology rehabilitation will be provided. This approach aligns with the trend of moving non-complex healthcare services into the patients' home environment.

TRIAL REGISTRATION

ClinicalTrials.Gov Identifier: NCT05779605.

Using cardiorespiratory fitness to operationalize vitality: a path analysis on the hierarchical structure of intrinsic capacity

BACKGROUND

There is a lack of consensus about the operationalization of vitality, which is one of the intrinsic capacity (IC) domains. In particular, no study has investigated whether cardiorespiratory fitness (CRF) can be considered a vitality indicator.

OBJECTIVE

To examine whether vitality is the upstream domain of IC, and establish the validity of CRF as a vitality indicator, using maximal oxygen consumption (VO2 max) as a representative.

METHODS

561 older adults from a longitudinal cohort study were included. Variables under consideration were VO2 max, other IC domains, instrumental activities of daily living (IADL), and handgrip strength, which was considered an already validated indicator of vitality. Using handgrip strength as the reference point, path analyses were performed to examine whether VO2 max followed a similar hierarchical structure in predicting change in IADL difficulty through other IC domains.

RESULTS

The mean age of the participants was 75.5 years. The path model in which vitality was measured by VO2 max demonstrated adequate fit, which was similar to the model in which vitality was measured by handgrip strength. Regarding the path coefficients, the model using VO2 max demonstrated significant total and indirect effects. Notably, the indirect effect was due to the locomotor domain (standardized coefficient = -0.148, p < .001), but not the cognitive or psychological domain.

CONCLUSION

Vitality is the upstream domain of IC. VO2 max can be considered an indicator to operationalize the vitality concept.

Timing of cardio-oncological rehabilitation and cardiorespiratory fitness in patients receiving cardiotoxic chemotherapy: a longitudinal observational study

AIMS

Anthracycline-based chemotherapy has well-known cardiotoxic effects, butmay also cause skeletal muscle myopathy and negatively affect cardiorespiratory fitness and quality of life. The effectiveness of exercise training in improving cardiorespiratory fitness and quality of life during chemotherapy is highly variable. We set out to determine how the effect of exercise training on cardiorespiratory fitness (primary outcome) and quality of life (secondary outcome) in cancer patients is affected by the type of therapy they receive (cardiotoxic therapy with or without anthracyclines; non-cardiotoxic therapy) and the timing of the exercise training (during or after therapy).

METHODS

Consecutive patients with cancer who participated in an exercise-based cardio-oncology rehabilitation programme at a university hospital in Switzerland between January 2014 and February 2022 were eligible. Patients were grouped based on chemotherapy (anthracycline vs non-anthracycline) and timing of exercise training (during vs after chemotherapy). Peak oxygen uptake (VO2) was assessed with cardiopulmonary exercise testing (n = 200), and quality of life with the Functional Assessment of Cancer Therapies questionnaire (n = 77). Robust linear models were performed for change in peak VO2 including type and timing of cardiotoxic therapies, age, training impulse and baseline peak VO2; change in quality of life was analysed with cumulative linked models.

RESULTS

In all patients with valid VO2 (n = 164), median change in peak VO2 from before to after exercise training was 2.3 ml/kg/min (range: -10.1-15.9). The highest median change in peak VO2 was 4.1 ml/kg/min (interquartile range [IQR]: 0.7-7.7) in patients who completed exercise training during non-anthracycline cardiotoxic or non-cardiotoxic therapies, followed by 2.8 ml/kg/min (IQR: 1.2-5.3) and 2.3 ml/kg/min (IQR: 0.1-4.6) in patients who completed exercise training after anthracycline and after non-anthracycline cardiotoxic or non-cardiotoxic therapies, respectively. In patients who completed exercise training during anthracycline therapy, peak VO2 decreased by a median of -2.1 ml/kg/min (IQR: -4.7-2.0). In the robust linear model, there was a significant interaction between type and timing of cancer treatment for anthracycline therapy, with greater increases in peak VO2 when exercise training was performed after anthracycline therapy. For quality of life, higher baseline scores were negatively associated with changes in quality of life.

CONCLUSION

In our cohort, the increase in cardiorespiratory fitness was diminished when exercise training was performed concurrently with anthracyclines. For patients with cardiotoxic treatments other than anthracyclines, cardiorespiratory fitness and quality of life was not associated with timing of exercise training.

Unraveling the link between cardiorespiratory fitness and cancer: a state-of-the-art review

Cardiorespiratory fitness (CRF) not only reflects an individual's capacity to perform physical activities but also encapsulates broader effects on the basic biology of aging. This review aims to summarize the evidence on the influence of CRF on overall and site-specific cancer risks. It delves into the biological mechanisms through which CRF may exert its effects, explores the clinical implications of these findings, identifies gaps in the current evidence base, and suggests directions for future research. The synthesis of findings reveals that higher CRF levels (general threshold of > 7 METs) are consistently associated with a reduced risk of a range of cancers, including head and neck, lung, breast, gastrointestinal, particularly pancreatic and colorectal, bladder, overall cancer incidence and mortality, and potentially stomach and liver, bile duct, and gall bladder cancers. These inverse associations between CRF and cancer risk do not generally differ across age groups, sex, race, or adiposity, suggesting a universal protective effect of CRF. Nonetheless, evidence linking CRF with skin, mouth and pharynx, kidney, and endometrial cancers is limited and inconclusive. Conversely, higher CRF levels may be potentially linked to an increased risk of prostate cancer and hematological malignancies, such as leukemia and myeloma, although the evidence is still not conclusive. CRF appears to play a significant role in reducing the risk of several cancers through various biological mechanisms, including inflammation reduction, immune system enhancement, hormonal regulation, and metabolic improvements. Overall, enhancing CRF through regular physical activity offers a vital, accessible strategy for reducing cancer risk and extending the health span. Future research should aim to fill the existing evidence gaps regarding specific cancers and elucidate the detailed dose-response relationships between CRF levels and cancer risk. Studies are also needed to elucidate the causal relationships and mechanistic pathways linking CRF to cancer outcomes.

The Association between Cardiorespiratory Fitness and the Risk of Breast Cancer in Women

INTRODUCTION

Studies have shown an inverse association between the risk of breast cancer in women and physical activity. However, information on the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized test and the risk of developing breast cancer is limited.

PURPOSE

To examine the CRF-breast cancer risk association in healthy females.

METHODS

This retrospective study was derived from the Exercise Testing and Health Outcomes Study cohort ( n = 750,302). Female participants ( n = 44,463; mean age ± SD; 55.1 ± 8.9 yr) who completed an exercise treadmill test evaluation (Bruce protocol) at the Veterans Affairs Medical Centers nationwide from 1999 to 2020 were studied. The cohort was stratified into four age-specific CRF categories (Least-fit, Low-fit, Moderate-fit, and Fit), based on the peak METs achieved during the exercise treadmill test.

RESULTS

During 438,613 person-years of observation, 994 women developed breast cancer. After controlling for covariates, the risk of breast cancer was inversely related to exercise capacity. For each 1-MET increase in CRF, the risk of cancer was 7% lower (HR, 0.93; 95% CI, 0.90-0.95; P < 0.001). When risk was assessed across CRF categories with the Least-fit group as the referent, the risk was 18% lower for Low-fit women (HR, 0.82; 95% CI, 0.70-0.96; P = 0.013), 31% for Moderate-fit (HR, 0.69; 95% CI, 0.58-0.82; P < 0.001), and 40% for Fit (HR, 0.60; 95% CI, 0.47-0.75; P < 0.001).

CONCLUSIONS

We observed an inverse and graded association between CRF and breast cancer risk in women. Thus, encouraging women to improve CRF may help attenuate the risk of developing breast cancer.

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity

PURPOSE OF REVIEW

Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk.

RECENT FINDINGS

Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

Longitudinal association between fitness and metabolic syndrome: a population-based study over 29 years follow-up

OBJECTIVES

To examine the longitudinal associations between fitness and metabolic syndrome (MetS) in community-dwelling adults over 29 years of follow-up.

DESIGN

Ongoing, population-based cohort study of adults aged ≥ 33 years at baseline residing in the city of Bad Schönborn, Germany.

METHODS

The sample comprised 89 persons (41 females; mean age 40.1 years at baseline) who participated at baseline (in the year 1992) and 29-years follow-up (in the year 2021). Fitness (predictor variable) was assessed using 15 standardized and validated tests that measured strength, gross motor coordination, mobility/ flexibility and cardiorespiratory fitness/ endurance, and a z-transformed fitness score was calculated for analysis. MetS (outcome of interest) was assessed through five criteria related to waist circumference, blood glucose, HDL cholesterol, triglycerides, and blood pressure, and a sum score was created for analysis. We ran partial correlations to examine the association between fitness score at baseline and MetS score at 29-years follow-up, adjusted for age, sex, socio-economic status, smoking status, sleep quality, and physical activity engagement in minutes/ week.

RESULTS

A higher fitness score at baseline was significantly associated with a lower MetS score indicative of better metabolic health at 29-years follow-up (r=-0.29; p = 0.011). These associations were present in participants aged ≤ 40 years (r=-0.33; p = 0.025) as well as those aged > 40 years (r=-0.43; p = 0.045).

CONCLUSIONS

Fitness may be a predictor of longitudinal metabolic health, and potentially also mediates previously reported longitudinal associations between physical activity and metabolic health. More research is needed to confirm these observations, and to also explore underlying mechanisms.

The Effect of Sedentary Behaviour on Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis

BACKGROUND

Cardiorespiratory fitness (CRF) is an important indicator of current and future health. While the impact of habitual physical activity on CRF is well established, the role of sedentary behaviour (SB) remains less understood.

OBJECTIVE

We aimed to determine the effect of SB on CRF.

METHODS

Searches were conducted in MEDLINE, Embase, PsycINFO, CINAHL and SPORTDiscus from inception to August 2022. Randomised controlled trials, quasi-experimental studies and cohort studies that assessed the relationship between SB and CRF were eligible. Narrative syntheses and meta-analyses summarised the evidence, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) certainty was based on evidence from randomised controlled trials.

RESULTS

This review included 18 studies that focused on youth (four randomised controlled trials, three quasi-experimental studies, 11 cohort studies) and 24 on adult populations (15 randomised controlled trials, five quasi-experimental studies, four cohort studies). In youth and adults, evidence from randomised controlled trials suggests mixed effects of SB on CRF, but with the potential for interventions to improve CRF. Quasi-experimental and cohort studies also support similar conclusions. Certainty of evidence was very low for both age groups. A meta-analysis of adult randomised controlled trials found that interventions targeting reducing SB, or increasing physical activity and reducing SB, had a significant effect on post-peak oxygen consumption (mean difference = 3.16 mL.kg-1.min-1, 95% confidence interval: 1.76, 4.57).

CONCLUSIONS

Evidence from randomised controlled trials indicates mixed associations between SB and CRF, with the potential for SB to influence CRF, as supported by meta-analytical findings. Further well-designed trials are warranted to confirm the relationship between SB and CRF, explore the effects of SB independent from higher intensity activity, and investigate the existence of such relationships in paediatric populations.

CLINICAL TRIAL REGISTRATION

PROSPERO CRD42022356218.

Demographic, clinical, and sociocognitive determinants related to physical activity and dietary intake in patients with ovarian cancer: A cross-sectional study

OBJECTIVE

To study physical activity and dietary intake among patients with ovarian cancer and to examine which demographic, clinical, and sociocognitive determinants are associated with these behaviours.

METHODS

This cross-sectional study included 139 patients with ovarian cancer scheduled for (neo)adjuvant chemotherapy. Physical activity was measured with the Physical Activity Scale for the Elderly questionnaire (PASE). Dietary intake was measured with a questionnaire assessing energy and protein intake and a questionnaire assessing adherence to the World Cancer Research Fund (WCRF) lifestyle recommendations. Demographic, clinical, and sociocognitive (e.g., self-efficacy) determinants of physical activity and dietary intake were examined using backward linear regression analyses.

RESULTS

Patients reported a median PASE score of 50 (IQR 24-94), a mean ± SD dietary intake of 1831 ± 604 kcal/day and 76 ± 27 g protein/day. Patients adhered to 3 out of 5 WCRF lifestyle recommendations. The absence of comorbidities, lower physical outcome expectations, and higher cancer specific outcome expectations were independently associated with higher physical activity levels. Higher age, lower cancer specific outcome expectations, and higher diet-related self-efficacy were significantly associated with adhering to more WCRF lifestyle recommendations, whilst no variables associated with total caloric or protein intake were identified.

CONCLUSIONS

Patients with ovarian cancer have low physical activity levels and a suboptimal diet, particularly low fruit and vegetable consumption and dietary fibre intake. Interventions aiming to improve physical activity and dietary intake could focus on increasing self-efficacy and outcome expectations, and should consider age and comorbidity as factors that may impact behaviour.

TRIAL REGISTRATION

Netherlands Trial Registry NTR6300.

Guarding the heart: How SGLT-2 inhibitors protect against chemotherapy-induced cardiotoxicity: SGLT-2 inhibitors and chemotherapy-induced cardiotoxicity

The introduction of chemotherapy agents has significantly transformed cancer treatment, with anthracyclines being one of the most commonly used drugs. While these agents have proven to be highly effective against various types of cancers, they come with complications, including neurotoxicity, nephrotoxicity, and cardiotoxicity. Among these side effects, cardiotoxicity is the leading cause of morbidity and mortality, with anthracyclines being the primary culprit. Chemotherapy medications have various mechanisms that can lead to cardiac injury. Hence, numerous studies have been conducted to decrease the cardiotoxicity of these treatments. Combination therapy with beta-blockers, Angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers have effectively reduced such outcomes. However, a definitive preventive strategy is yet to be established. Meanwhile, sodium-glucose co-transporter-2 (SGLT-2) inhibitors lower blood glucose levels in type 2 diabetes by reducing its re-absorption in the kidneys. They are thus considered potent drugs for glycemic control and reduction of cardiovascular risks. Recent studies have shown that SGLT-2 inhibitors are crucial in preventing chemotherapy-induced cardiotoxicity. They enhance heart cell viability, prevent degenerative changes, stimulate autophagy, and reduce cell death. This drug class also reduces inflammation by inhibiting reactive oxygen species and inflammatory cytokine production. Moreover, it can not only reverse the harmful effects of anticancer agents on the heart structure but also enhance the effectiveness of chemotherapy by minimizing potential consequences on the heart. In conclusion, SGLT-2 inhibitors hold promise as a therapeutic strategy for protecting cancer patients from chemotherapy-induced heart damage and improving cardiovascular outcomes.

Usual-paced 400 m long distance corridor walk estimates cardiorespiratory fitness among older adults: The Study of Muscle, Mobility and Aging

BACKGROUND

Cardiopulmonary exercise testing (CPET), the gold-standard method to quantify cardiorespiratory fitness (CRF), is not always feasible due to cost, access, and burden. The usual-paced 400 m long distance corridor walk (LDCW), a measure of mobility among older adults, may provide an alternate method to assess CRF. The purpose of this study was to develop and validate an estimating equation to estimate VO2 peak from average 400 m walking speed (WS) among participants in the Study of Muscle, Mobility and Aging (SOMMA).

METHODS

At baseline, women (58%) and men age 70 years and older enrolled in SOMMA (N = 820, 76.2 ± 4.9 years, 86% Non-Hispanic White) completed a 400 m LDCW (400 m WS = 400 m/completion time in seconds) and symptom-limited maximal CPET (Modified Balke Protocol). VO2 peak (mL/kg/min) was considered the highest 30-second average oxygen consumption during CPET. Other covariates included: age, sex, race, physical activity (7-day wrist-worn accelerometer), physical function (Short Physical Performance Battery, range 0-12), perceived physical fatigability (Pittsburgh Fatigability Scale, range 0-50), and Borg Rating of Perceived Exertion (RPE, range 6-20) at completion of the 400 m LDCW. Stepwise linear regression was used. Internal validation was completed using data-splitting method (70%; 30%).

RESULTS

Mean VO2 peak was 20.2 ± 4.8 mL/kg/min and mean 400 m WS was 1.06 ± 0.2 m/s. Each 0.05 m/s increment in 400 m WS was associated with a 0.40 mL/kg/min higher VO2 peak after covariate adjustment. An estimating equation including 400 m WS, age, sex, race, and RPE was developed. Internal validation showed low overall bias (-0.26) and strong correlation (r = 0.71) between predicted and measured VO2 peak values. Bland-Altman plot and regression analyses indicated predicted VO2 peak was an acceptable alternative, despite mean underestimation of 4.53 mL/kg/min among the highly fit.

CONCLUSIONS

Usual-paced 400 m LDCW strongly correlates with direct measures of CRF during CPET in older adults with lower fitness and can be used to test both fitness and function.

2023 update: The importance of cardiorespiratory fitness in the United States

The American Heart Association issued a Policy Statement in 2013 that characterized the importance of cardiorespiratory fitness (CRF) as an essential marker of health outcomes and specifically the need for increased assessment of CRF. This statement summarized the evidence demonstrating that CRF is "one of the most important correlates of overall health status and a potent predictor of an individual's future risk of cardiovascular disease." Subsequently, this Policy Statement led to the development of a National Registry for CRF (Fitness Registry and the Importance of Exercise: A National Data Base [FRIEND]) which established normative reference values for CRF for adults in the United States (US). This review provides an overview of the progress made in the past decade to further our understanding of the importance of CRF, specifically related to prevention and for clinical populations. Additionally, this review overviews the evolvement and additional uses of FRIEND and summarizes a hierarchy of assessment methods for CRF. In summary, continued efforts are needed to expand the representation of data from across the US, and to include data from pediatric populations, to further develop the CRF Reference Standards for the US as well as further develop Global CRF Reference Standards.

Deep learned representations of the resting 12-lead electrocardiogram to predict at peak exercise

AIMS

To leverage deep learning on the resting 12-lead electrocardiogram (ECG) to estimate peak oxygen consumption (V˙O2peak) without cardiopulmonary exercise testing (CPET).

METHODS AND RESULTS

V ˙ O 2 peak estimation models were developed in 1891 individuals undergoing CPET at Massachusetts General Hospital (age 45 ± 19 years, 38% female) and validated in a separate test set (MGH Test, n = 448) and external sample (BWH Test, n = 1076). Three penalized linear models were compared: (i) age, sex, and body mass index ('Basic'), (ii) Basic plus standard ECG measurements ('Basic + ECG Parameters'), and (iii) basic plus 320 deep learning-derived ECG variables instead of ECG measurements ('Deep ECG-V˙O2'). Associations between estimated V˙O2peak and incident disease were assessed using proportional hazards models within 84 718 primary care patients without CPET. Inference ECGs preceded CPET by 7 days (median, interquartile range 27-0 days). Among models, Deep ECG-V˙O2 was most accurate in MGH Test [r = 0.845, 95% confidence interval (CI) 0.817-0.870; mean absolute error (MAE) 5.84, 95% CI 5.39-6.29] and BWH Test (r = 0.552, 95% CI 0.509-0.592, MAE 6.49, 95% CI 6.21-6.67). Deep ECG-V˙O2 also outperformed the Wasserman, Jones, and FRIEND reference equations (P < 0.01 for comparisons of correlation). Performance was higher in BWH Test when individuals with heart failure (HF) were excluded (r = 0.628, 95% CI 0.567-0.682; MAE 5.97, 95% CI 5.57-6.37). Deep ECG-V˙O2 estimated V˙O2peak <14 mL/kg/min was associated with increased risks of incident atrial fibrillation [hazard ratio 1.36 (95% CI 1.21-1.54)], myocardial infarction [1.21 (1.02-1.45)], HF [1.67 (1.49-1.88)], and death [1.84 (1.68-2.03)].

CONCLUSION

Deep learning-enabled analysis of the resting 12-lead ECG can estimate exercise capacity (V˙O2peak) at scale to enable efficient cardiovascular risk stratification.

Cancer survivor inspiratory muscle training: systematic review and Bayesian meta-analysis

BACKGROUND

The long-term impact of cancer treatment is associated with respiratory dysfunction and physical fitness impairment. Although inspiratory muscle training (IMT) has been shown as an effective exercise therapy in cancer survivors, there is no evidence on the optimal dose, application moment nor specific population effects of this intervention. The main objective of this meta-analysis is to analyse the effects of IMT on pulmonary function, physical fitness and quality of life (QoL) in cancer survivors.

METHODS

This systematic review and meta-analysis was preregistered in the International Prospective Register of Systematic Reviews (PROSPERO) register and conducted according to the Preferred Reporting for Systematic Reviews and Meta-analysis statement. We used a Bayesian multilevel random-effects meta-analysis model to pool the data. Multilevel metaregression models were used to examine the conditional effects of our covariates. Convergence and model fit were evaluated through specific model parameters. Sensitivity analyses removing influential cases and using a frequentist approach were carried out.

RESULTS

Pooled data showed that IMT intervention is effective to improve pulmonary function (standardised mean difference=0.53, 95% credible interval 0.13 to 0.94, SE=0.19). However, IMT did not present statistically significant results on physical fitness and QoL. Metaregression analyses found that the type of cancer, the moment of application and the evaluation tool used had significant moderation effects on pulmonary function.

CONCLUSION

IMT could be an important part in the management of side effects suffered by cancer survivors. Considering the current evidence, this intervention is highly recommended in patients diagnosed with oesophageal and lung cancers. IMT may provide superior benefits before the biological treatment and after the surgery.

PROSPERO REGISTRATION NUMBER

304909.

Observational and genetic associations between cardiorespiratory fitness and cancer: a UK Biobank and international consortia study

BACKGROUND

The association of fitness with cancer risk is not clear.

METHODS

We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of lung, colorectal, endometrial, breast, and prostate cancer in a subset of UK Biobank participants who completed a submaximal fitness test in 2009-12 (N = 72,572). We also investigated relationships using two-sample Mendelian randomisation (MR), odds ratios (ORs) were estimated using the inverse-variance weighted method.

RESULTS

After a median of 11 years of follow-up, 4290 cancers of interest were diagnosed. A 3.5 ml O2⋅min-1⋅kg-1 total-body mass increase in fitness (equivalent to 1 metabolic equivalent of task (MET), approximately 0.5 standard deviation (SD)) was associated with lower risks of endometrial (HR = 0.81, 95% CI: 0.73-0.89), colorectal (0.94, 0.90-0.99), and breast cancer (0.96, 0.92-0.99). In MR analyses, a 0.5 SD increase in genetically predicted O2⋅min-1⋅kg-1 fat-free mass was associated with a lower risk of breast cancer (OR = 0.92, 95% CI: 0.86-0.98). After adjusting for adiposity, both the observational and genetic associations were attenuated.

DISCUSSION

Higher fitness levels may reduce risks of endometrial, colorectal, and breast cancer, though relationships with adiposity are complex and may mediate these relationships. Increasing fitness, including via changes in body composition, may be an effective strategy for cancer prevention.

The Benefit of Exercise in Patients With Cancer Who Are Receiving Chemotherapy: A Systematic Review and Network Meta-Analysis

OBJECTIVE

This study aimed to determine which therapeutic exercise-based intervention is most effective in improving cardiorespiratory fitness (CRF) in patients with cancer receiving chemotherapy.

METHODS

The authors conducted a systematic review with network meta-analysis in MEDLINE (PubMed), Embase, Cumulative Index to Nursing and Allied Health Literature, Scopus, SPORTDiscus, and Web of Science. The authors employed the Physiotherapy Evidence Database and the Revised Cochrane Risk of Bias Tool for Randomized Trials to assess the methodological quality and risk of bias, respectively.

RESULTS

A total of 27 studies were included. Data were pooled using a random-effects model. Adding aerobic training (moderate to high intensity), with or without resistance training, to usual care versus usual care was statistically significant, with a small beneficial effect (aerobic training: standardized mean difference = 0.46; 95% CI= 0.17 to 0.75; aerobic and resistance training: standardized mean difference = 0.26; 95% CI = 0.00 to 0.52) for peak oxygen consumption at the postintervention assessment.

CONCLUSION

Therapeutic exercise-based interventions to improve short-term CRF in patients with cancer receiving chemotherapy should include moderate- to high-intensity aerobic exercise, with or without resistance training.

IMPACT

It is important to improve CRF in the oncological population due to its relationship with mortality. The results showed the benefit of exercise to improve cardiorespiratory fitness in the oncology population receiving chemotherapy treatment.

Home-based high-intensity interval training improves cardiorespiratory fitness: a systematic review and meta-analysis

BACKGROUND

High-intensity interval training (HIIT) is an effective methods to improve maximal oxygen uptake. However, there is no definitive conclusion about the specific effectiveness of home-based HIIT. This review investigated the effects of home-based HIIT on cardiorespiratory fitness in a systematic review and meta-analysis.

METHODS

Four electronic databases were searched (PubMed, Cochran database, Web of Science, Igaku Chuo Zasshi) for studies through March 25, 2023. Eligibility criteria include randomized controlled trials of home-based HIIT in adult people regardless disease or handicaped. Comparisons were made between non-exercise controls, laboratory-based HIIT, and moderate-intensity continuous training (MICT). The primary outcome was defined as cardiorespiratory fitness and the secondary outcome was defined as patient-reported outcomes. The standardized mean difference (SMD) with 95% confidence intervals (CIs) was calculated for quantitative indices. The random-effect model was used as the pooling method.

RESULTS

Two hundred seven studies were identified, and 15 satisfied the inclusion criteria. The meta-analysis for cardiorespiratory fitness showed superiority of home-based HIIT to non-exercise controls (SMD 0.61, 95% CI: 0.21, 1.02). However, no significant difference in cardiorespiratory fitness was observed between home-based HIIT and lab-based HIIT (SMD: -0.35, 95%CI: -0.73, 0.03). Also, no significant difference was observed between the home-based HIIT and MICT (SMD 0.34, 95% CI: -0.05, 0.73).

CONCLUSION

These results indicated that home-based HIIT was an effective intervention for improving cardiorespiratory fitness in healthy adults and patients. Importantly, this review found no significant differences in cardiorespiratory fitness between home-based HIIT and the group of laboratory HIIT and MICT, highlighting its comparable effectiveness and potential as a practical and valuable exercise intervention.

Surveillance cardiopulmonary exercise testing can risk-stratify childhood cancer survivors: underlying pathophysiology of poor exercise performance and possible room for improvement

BACKGROUND

Asymptomatic childhood cancer survivors (CCS) frequently show decreased exercise performance. Poor exercise performance may indicate impaired future cardiovascular health.

METHODS

Cardiopulmonary exercise testing (CPET) was performed in asymptomatic off-treatment CCS (age ≥ 10 years). Patients were divided into Normal and Poor performance groups by %predicted maximum VO2 at 80%. Both peak and submaximal CPET values were analyzed.

RESULTS

Thirty-eight males (19 Normal, 19 Poor) and 40 females (18 Normal, 22 Poor) were studied. Total anthracycline dosage was comparable among 4 groups. The body mass index (BMI), although normal, and weight were significantly higher in Poor groups. Peak heart rate (HR) and peak respiratory exchange ratio (RER) were comparable in all four groups. Peak work rate (pWR)/kg, peak oxygen consumption (pVO2)/kg, peak oxygen pulse (pOP)/kg, and ventilatory anaerobic threshold (VAT)/kg were significantly lower, whereas heart rate (HR) increase by WR/kg (ΔHR/Δ[WR/kg] was significantly higher in Poor groups. Simultaneously plotting of weight & pVO2 and ΔHR/ΔWR & ΔVO2/ΔHR revealed a distinct difference between the Normal and Poor groups in both sexes, suggesting decreased skeletal muscle mass and decreased stroke volume reserve, respectively, in Poor CCS. The relationship between VAT and pVO2 was almost identical between the two groups in both sexes. Ventilatory efficiency was mildly diminished in the Poor groups.

CONCLUSIONS

Decreased skeletal muscle mass, decreased stroke volume reserve, and slightly decreased ventilatory efficiency characterize Poor CCS in both sexes. This unique combined CPET analysis provides useful clinical biomarkers to screen subclinical cardiovascular abnormality in CCS and identifies an area for improvement.

Usual-Paced 400m Long Distance Corridor Walk Estimates Cardiorespiratory Fitness among Older Adults: The Study of Muscle, Mobility and Aging (SOMMA)

Background

Cardiopulmonary exercise testing (CPET), the gold-standard method to quantify cardiorespiratory fitness (CRF), is not always feasible due to cost, access, and burden. The usual-paced 400m long-distance corridor walk (LDCW), a measure of mobility among older adults, may provide an alternate method to assess CRF among populations unable to complete maximal intensity testing. The purpose of this study was to develop and validate an estimating equation to estimate VO 2 peak from average 400m walking speed (WS) among participants in the Study of Muscle, Mobility and Aging (SOMMA).

Methods

At baseline, participants (N=820, 76.2±4.9 years, 58% Women, 86% Non-Hispanic White) completed a 400m LDCW (400m WS=400m/completion time in seconds) and symptom-limited maximal CPET (Modified Balke Protocol). VO 2 peak (mL/kg/min) was considered the highest 30-second average oxygen consumption during CPET. Other covariates included: age, sex, race, physical activity (7-day wrist-worn accelerometer), physical function (Short Physical Performance Battery, range 0-12), perceived physical fatigability (Pittsburgh Fatigability Scale, range 0-50), and Borg Rating of Perceived Exertion (RPE, range 6-20) at completion of the 400m LDCW. Stepwise linear regression was used. Internal validation was completed using data-splitting method (70%; 30%).

Results

Mean VO 2 peak was 20.2±4.8 mL/kg/min and mean 400m WS was 1.06±0.2 m/s. Each 0.05 m/s increment in 400m WS was associated with a 0.40 mL/kg/min higher VO 2 peak after adjustment for covariates. An estimating equation including 400m WS, age, sex, race, and RPE was developed. Internal validation showed low overall bias (-0.26) and strong correlation (r = 0.71) between predicted and measured VO 2 peak values. Bland-Altman plot and regression analyses indicated predicted VO 2 peak was an acceptable alternative, despite mean underestimation of 4.53 mL/kg/min among those with CPET VO 2 peak ≥25 mL/kg/min.

Conclusions

Usual-paced 400m LDCW strongly correlates with direct measures of cardiorespiratory fitness during CPET in older adults with lower fitness and can be used to test both fitness and function.

Home-based prehabilitation improves physical conditions measured by ergospirometry and 6MWT in colorectal cancer patients: a randomized controlled pilot study

PURPOSE/BACKGROUND

Prehabilitation aims to improve physical condition in the preoperative period and, therefore, decrease the loss of cardiopulmonary capacity postoperatively, with the aim of reducing complications and promoting an early recovery. This study aims to evaluate the impact of home-based prehabilitation on the physical condition of patients treated surgically for colorectal cancer.

METHODS

A prospective and randomized clinical study was conducted on 60 patients during two periods from October 2018 to February 2019 and from September 2019 to September 2020, in a single university hospital. Patients were randomized into two study groups (30 per group): prehabilitation vs. standard care. Changes in physical condition, measured at diagnosis, the day before surgery, and at 6-8 weeks after surgery using the cardiopulmonary exercise testing (CPET) and the 6-minute walk test (6MWT) were evaluated.

RESULTS

Prehabilitation reduced postoperative complications (17.4% vs. 33.3%, p = 0.22) and hospital stay (5.74 vs. 6.67 days, p = 0.30). 6MWT showed a significant improvement in the prehabilitation group (+78.9 m). Six weeks after surgery, prehabilitation showed a significant improvement in the 6MWT (+68.9 m vs. -27.2 m, p = 0.01). Significant differences were also observed in the ergospirometry between the diagnosis and postoperative study (+0.79 METs vs. -0.84 METs, p = 0.001). A strong correlation was observed between CPET and 6MWT (0.767 (p < 0.001)).

CONCLUSION

Home prehabilitation achieved lower overall postoperative complications than standard care and reached significant improvements in 6MWT and CET. A strong correlation was observed between CET and 6MWT, which allows validation of 6MWT as a valid and reliable measure of functional exercise capacity in colorectal patients when other, more specific and expensive tests are not available.

TRIAL REGISTRATION

Registered in ClinicalTrials.gov in August 2018 with registration number https://clinicaltrials.gov/study/NCT03618329?cond=Prehabilitation%20cancer&term=arroyo&distance=50&rank=1  (NCT03618329). Initial results published in Supportive Care in Cancer: Effect of home-based prehabilitation in an enhanced recovery after surgery program for patients undergoing colorectal cancer surgery during the COVID-19 pandemic. DOI: https://doi.org/10.1007/s00520-021-06343-1 .

The evolving role of cardiopulmonary exercise testing in ischemic heart disease - state of the art review

PURPOSE OF REVIEW

Cardiopulmonary exercise testing (CPET) is the gold standard for directly assessing cardiorespiratory fitness (CRF) and has a relatively new and evolving role in evaluating atherosclerotic heart disease, particularly in detecting cardiac dysfunction caused by ischemic heart disease. The purpose of this review is to assess the current literature on the link between cardiovascular (CV) risk factors, cardiac dysfunction and CRF assessed by CPET.

RECENT FINDINGS

We summarize the basics of exercise physiology and the key determinants of CRF. Prognostically, several studies have been published relating directly measured CRF by CPET and outcomes allowing for more precise risk assessment. Diagnostically, this review describes in detail what is considered healthy and abnormal cardiac function assessed by CPET. New studies demonstrate that cardiac dysfunction on CPET is a common finding in asymptomatic individuals and is associated with CV risk factors and lower CRF. This review covers how key CPET parameters change as individuals transition from the asymptomatic to the symptomatic stage with progressively decreasing CRF. Finally, a supplement with case studies with long-term longitudinal data demonstrating how CPET can be used in daily clinical decision making is presented.

SUMMARY

In summary, CPET is a powerful tool to provide individualized CV risk assessment, monitor the effectiveness of therapeutic interventions, and provide meaningful feedback to help patients guide their path to improve CRF when routinely used in the outpatient setting.

Self-reported walking pace and 10-year cause-specific mortality: A UK biobank investigation

OBJECTIVE

To investigate associations of self-reported walking pace (SRWP) with relative and absolute risks of cause-specific mortality.

PATIENTS AND METHODS

In 391,652 UK Biobank participants recruited in 2006-2010, we estimated sex- and cause-specific (cardiovascular disease [CVD], cancer, other causes) mortality hazard ratios (HRs) and 10-year mortality risks across categories of SRWP (slow, average, brisk), accounting for confounders and competing risk. Censoring occurred in September 30, 2021 (England, Wales) and October 31, 2021 (Scotland).

RESULTS

Over a median follow-up of 12.6 years, 22,413 deaths occurred. In women, the HRs comparing brisk to slow SRWP were 0.74 (95% CI: 0.67, 0.82), 0.40 (0.33, 0.49), and 0.29 (0.26, 0.32) for cancer, CVD, and other causes of death, respectively, and 0.71 (0.64, 0.78), 0.38 (0.33, 0.44), and 0.29 (0.26, 0.32) in men. Compared to CVD, HRs were greater for other causes (women: 39.6% [6.2, 72.9]; men: 31.6% [9.8, 53.5]) and smaller for cancer (-45.8% [-58.3, -33.2] and - 45.9% [-54.8, -36.9], respectively). For all causes in both sexes, the 10-year mortality risk was higher in slow walkers, but varied across sex, age, and cause, resulting in different risk reductions comparing brisk to slow: the largest were for other causes of death at age 75 years [women: -6.8% (-7.7, -5.8); men: -9.5% (-10.6, -8.4)].

CONCLUSION

Compared to slow walkers, brisk SRWP was associated with reduced cancer (smallest reduction), CVD, and other (largest) causes of death and may therefore be a useful clinical predictive marker. As absolute risk reductions varied across age, cause, and SRWP, certain groups may particularly benefit from interventions to increase SRWP.

Effects of high-intensity interval training on functional performance and maximal oxygen uptake in comparison with moderate intensity continuous training in cancer patients: a systematic review and meta-analysis

INTRODUCTION

High-intensity interval training (HIIT) is an appropriate training modality to improve endurance and therefore contributes to physical performance. This review investigates the effect of HIIT on functional performance in cancer patients. We reviewed the relative peak oxygen uptake (relV̇O2PEAK) and meta-analytical compared HIIT with moderate intensity continuous training (MICT). Furthermore, we took various training parameters under consideration.

METHODS

A systematic literature search was conducted in Scopus, PubMed, and Cochrane Library databases. For the review, we included randomized controlled trials containing HIIT with cancer patients. From this, we filtered interventions with additional MICT for the meta-analysis. Outcomes of interest were various functional performance assessments and V̇O2MAX.

RESULTS

The research yielded 584 records which fit the inclusion criteria, of which 31 studies with n=1555 patients (57.4±8.6 years) could be included in the overall review and 8 studies in the meta-analysis (n=268, 59.11±5.11 years) regarding relV̇O2PEAK. Different functional outcomes were found, of which walking distance (+8.63±6.91% meters in 6-min walk test) and mobility (+2.7cm in sit and reach test) improved significantly due to HIIT. In terms of relV̇O2PEAK, the performance of cancer patients was improved by HIIT (10.68±6.48%) and MICT (7.4±4.29%). HIIT can be favored to increase relV̇O2PEAK (SMD 0.37; 95% CI 0.09-0.65; I2=0%; p=0.009). Effect sizes for relV̇O2PEAK improvements correlate moderately with total training volume (Spearman's ρ=0.49; p=0.03), whereas percentage increases do not (Spearman's ρ=0.24; p=0.14).

CONCLUSION

Functional and physical outcomes were positively altered by different HIIT protocols and forms of implementation, whereas a tendency toward more effectiveness of HIIT vs. MICT was found for relV̇O2PEAK. Future studies should include functional parameters more often, to finally allow a comparison between both training protocols in this regard.

Running with whole-body electromyostimulation improves physiological determinants of endurance performance - a randomized control trial

BACKGROUND

This study aimed to evaluate the physiological and metabolic adaptations to an eight-week running intervention with whole-body electromyostimulation (wbEMS) compared to running without wbEMS.

METHODS

In a randomized controlled trial (RCT), 59 healthy participants (32 female/ 27 male, 41 ± 7 years, rel.V̇O2max 40.2 ± 7.4 ml/min/kg) ran twice weekly à 20 min for eight weeks either with a wbEMS suit (EG) or without wbEMS (control group, CG). Before and after the intervention, (i) rel.V̇O2max, heart rate and time to exhaustion were recorded with an incremental step test with an incremental rate of 1.20 km/h every 3 min. They were interpreted at aerobic and (indirect) anaerobic lactate thresholds as well as at maximum performance. (ii) Resting metabolic rate (RQ) as well as (iii) body composition (%fat) were assessed.

RESULTS

Following the intervention, V̇O2max was significantly enhanced for both groups (EG ∆13 ± 3%, CG ∆9 ± 3%). Velocity was elevated at lactate thresholds and maximum running speed (EG ∆3 ± 1%, CG ∆2 ± 1%); HRmax was slightly reduced by -1 beat/min. No significant changes were observed for time until exhaustion and lactate. RQ was significantly enhanced following both trainings by + 7%. %fat was reduced for both groups (EG ∆-11 ± 3%, CG ∆-16 ± 5%), without any changes in body mass. Results did not differ significantly between groups.

CONCLUSIONS

Both interventions had a positive impact on aerobic power. The rightward shift of the time-velocity graph points towards improved endurance performance. The effects of wbEMS are comparable to those after high-intensity training and might offer a time-efficient alternative to affect physiological and metabolic effects.

TRIAL REGISTRATION

German Clinical Trials Register, ID DRKS00026827, date 10/26/21.

Exploring shared genetics between maximal oxygen uptake and disease: the HUNT study

Low cardiorespiratory fitness, measured as maximal oxygen uptake (V̇o2max), is associated with all-cause mortality and disease-specific morbidity and mortality and is estimated to have a large genetic component (∼60%). However, the underlying mechanisms explaining the associations are not known, and no association study has assessed shared genetics between directly measured V̇o2max and disease. We believe that identifying the mechanisms explaining how low V̇o2max is related to increased disease risk can contribute to prevention and therapy. We used a phenome-wide association study approach to test for shared genetics. A total of 64,479 participants from the Trøndelag Health Study (HUNT) were included. Genetic variants previously linked to V̇o2max were tested for association with diseases related to the cardiovascular system, diabetes, dementia, mental disorders, and cancer as well as clinical measurements and biomarkers from HUNT. In the total population, three single-nucleotide polymorphisms (SNPs) in and near the follicle-stimulating hormone receptor gene (FSHR) were found to be associated (false discovery rate < 0.05) with serum creatinine levels and one intronic SNP in the Rap-associating DIL domain gene (RADIL) with diabetes type 1 with neurological manifestations. In males, four intronic SNPs in the PBX/knotted homeobox 2 gene (PKNOX2) were found to be associated with endocarditis. None of the association tests in the female population reached overall statistical significance; the associations with the lowest P values included other cardiac conduction disorders, subdural hemorrhage, and myocarditis. The results might suggest shared genetics between V̇o2max and disease. However, further effort should be put into investigating the potential shared genetics between inborn V̇o2max and disease in larger cohorts to increase statistical power.NEW & NOTEWORTHY To our knowledge, this is the first genetic association study exploring how genes linked to cardiorespiratory fitness (CRF) relate to disease risk. By investigating shared genetics, we found indications that genetic variants linked to directly measured CRF also affect the level of blood creatinine, risk of diabetes, and endocarditis. Less certain findings showed that genetic variants of high CRF might cause lower body mass index, healthier HDL cholesterol, and lower resting heart rate.

Incorporating Exercise Training into Cardio-Oncology Care: Current Evidence and Opportunities: JACC: CardioOncology State-of-the-Art Review

Cancer treatment-induced cardiotoxicities are an ongoing concern throughout the cancer care continuum from treatment initiation to survivorship. Several "standard-of-care" primary, secondary, and tertiary prevention strategies are available to prevent the development or further progression of cancer treatment-induced cardiotoxicities and their risk factors. Despite exercise's established benefits on the cardiovascular system, it has not been widely adopted as a nonpharmacologic cardioprotective strategy within cardio-oncology care. In this state-of-the-art review, the authors discuss cancer treatment-induced cardiotoxicities, review the existing evidence supporting the role of exercise in preventing and managing these sequelae in at-risk and affected individuals living after cancer diagnoses, and propose considerations for implementing exercise-based services in cardio-oncology practice.

High-intensity interval training in breast cancer patients: A systematic review and meta-analysis

BACKGROUND

Women with breast cancer and improved survival often experience treatment-related impairments. High-intensity interval training (HIIT) has emerged as a promising exercise therapy modality for adult cancer patients. However, the overall effects of HIIT in breast cancer patients remain scarce and controversial. Therefore, we conducted a systematic review and meta-analysis to comprehensively evaluate the impact of HIIT on health-related outcomes in breast cancer patients.

METHODS

We searched the PubMed, Embase, and Web of Science from inception to November 7, 2022. Eligible studies included randomized controlled trials that compared HIIT interventions with usual care (UC) or MICT in breast cancer patients. The primary outcome assessed was physical fitness, and exploratory outcomes included body composition, blood-borne biomarkers, and patient-reported outcomes. Summary data were extracted, and standardized mean differences (SMD) were calculated for meta-analysis. For outcomes that could not be pooled, a systematic review was conducted.

RESULTS

Our analysis included 19 articles from 10 studies, encompassing 532 participants who met the inclusion criteria. Pooled results demonstrated that HIIT was superior to UC in improving peak oxygen uptake (VO2peak ). The SMD for VO2peak (L/min) and VO2peak (mL/kg/min) was 0.79 (95% CI 0.13, 1.45) and 0.59 (95% CI 0.01, 1.16), respectively. No significant differences in VO2peak were found between the HIIT and MICT groups. Meta-analyses on body composition and blood-borne biomarkers showed no significant differences between HIIT and UC. Systematic review indicated favorable effects of HIIT on muscle strength, fatigue, and emotional well-being.

CONCLUSIONS

HIIT is a time-efficient alternative to MICT for improving VO2peak and may also enhance muscle strength and alleviate fatigue and emotional symptoms in breast cancer patients. HIIT should be considered as an important component of exercise prescription in breast cancer care. Further studies with larger cohorts are needed to determine the clinical significance of HIIT-induced changes in terms of other outcomes in women with breast cancer.

Effect of home-based online training and activity feedback on oxygen uptake in patients after surgical cancer therapy: a randomized controlled trial

BACKGROUND

Exercise training is beneficial in enhancing physical function and quality of life in cancer patients. Its comprehensive implementation remains challenging, and underlying cardiopulmonary adaptations are poorly investigated. This randomized controlled trial examines the implementation and effects of home-based online training on cardiopulmonary variables and physical activity.

METHODS

Of screened post-surgical patients with breast, prostate, or colorectal cancer, 148 were randomly assigned (1:1) to an intervention (2 × 30 min/week of strength-endurance training using video presentations) and a control group. All patients received activity feedback during the 6-month intervention period. Primary endpoint was change in oxygen uptake after 6 months. Secondary endpoints included changes in cardiac output, rate pressure product, quality of life (EORTC QoL-C30), C-reactive protein, and activity behavior.

RESULTS

One hundred twenty-two patients (62 intervention and 60 control group) completed the study period. Change in oxygen uptake between intervention and control patients was 1.8 vs. 0.66 ml/kg/min (estimated difference after 6 months: 1.24; 95% CI 0.23 to 2.55; p = 0.017). Rate pressure product was reduced in IG (estimated difference after 6 months: - 1079; 95% CI - 2157 to - 1; p = 0.05). Physical activity per week was not different in IG and CG. There were no significant interaction effects in body composition, cardiac output, C-reactive protein, or quality of life.

CONCLUSIONS

Home-based online training among post-surgery cancer patients revealed an increase of oxygen uptake and a decrease of myocardial workload during exercise. The implementation of area-wide home-based training and activity feedback as an integral component in cancer care and studies investigating long-term effects are needed.

TRIAL REGISTRATION

DRKS-ID: DRKS00020499 ; Registered 17 March 2020.

Association Between Cardiorespiratory Fitness and Cancer Incidence and Cancer-Specific Mortality of Colon, Lung, and Prostate Cancer Among Swedish Men

Importance

Cardiorespiratory fitness (CRF) levels appear to be an important risk factor for cancer incidence and death.

Objectives

To examine CRF and prostate, colon, and lung cancer incidence and mortality in Swedish men, and to assess whether age moderated any associations between CRF and cancer.

Design, Setting, and Participants

A prospective cohort study was conducted in a population of men who completed an occupational health profile assessment between October 1982 and December 2019 in Sweden. Data analysis was performed from June 22, 2022, to May 11, 2023.

Exposure

Cardiorespiratory fitness was assessed as maximal oxygen consumption, estimated using a submaximal cycle ergometer test.

Main Outcomes and Measures

Data on prostate, colon, and lung cancer incidence and mortality were derived from national registers. Hazard ratios (HRs) and 95% CIs were calculated using Cox proportional hazards regression.

Results

Data on 177 709 men (age range, 18-75 years; mean [SD] age, 42 [11] years; mean [SD] body mass index, 26 [3.8]) were analyzed. During a mean (SD) follow-up time of 9.6 (5.5) years, a total of 499 incident cases of colon, 283 of lung, and 1918 of prostate cancer occurred, as well as 152 deaths due to colon cancer, 207 due to lung cancer, and 141 deaths due to prostate cancer. Higher levels of CRF (maximal oxygen consumption as milliliters per minute per kilogram) were associated with a significantly lower risk of colon (HR, 0.98, 95% CI, 0.96-0.98) and lung cancer (HR, 0.98; 95% CI, 0.96-0.99) incidence, and a higher risk of prostate cancer incidence (HR, 1.01; 95% CI, 1.00-1.01). Higher CRF was associated with a lower risk of death due to colon (HR, 0.98; 95% CI, 0.96-1.00), lung (HR, 0.97; 95% CI, 0.95-0.99), and prostate (HR, 0.95; 95% CI, 0.93-0.97) cancer. After stratification into 4 groups and in fully adjusted models, the associations remained for moderate (>35-45 mL/min/kg), 0.72 (0.53-0.96) and high (>45 mL/min/kg), 0.63 (0.41-0.98) levels of CRF, compared with very low (<25 mL/min/kg) CRF for colon cancer incidence. For prostate cancer mortality, associations remained for low (HR, 0.67; 95% CI, 0.45-1.00), moderate (HR, 0.57; 95% CI, 0.34-0.97), and high (HR, 0.29; 95% CI, 0.10-0.86) CRF. For lung cancer mortality, only high CRF (HR, 0.41; 95% CI, 0.17-0.99) was significant. Age modified the associations for lung (HR, 0.99; 95% CI, 0.99-0.99) and prostate (HR, 1.00; 95% CI, 1.00-1.00; P < .001) cancer incidence, and for death due to lung cancer (HR, 0.99; 95% CI, 0.99-0.99; P = .04).

Conclusions and Relevance

In this cohort of Swedish men, moderate and high CRF were associated with a lower risk of colon cancer. Low, moderate, and high CRF were associated with lower risk of death due to prostate cancer, while only high CRF was associated with lower risk of death due to lung cancer. If evidence for causality is established, interventions to improve CRF in individuals with low CRF should be prioritized.

Effect of Polarized Training on Cardiorespiratory Fitness of Untrained Healthy Young Adults: A Randomized Control Trial with Equal Training Impulse

To explore the effects of 8-week polarized training (POL), high-intensity interval training (HIIT), and threshold training (THR) interventions on the cardiorespiratory fitness (CRF) of untrained healthy young adults. This study recruited 36 young adults and randomly assigned them to POL, HIIT, THR, or control (CG) groups to undergo an 8-week training intervention. The training impulse applied to all three intervention groups was identical. The training intensity was divided into Zone 1, 2, and 3 (Z1, Z2 and Z3) on the basis of the ventilatory thresholds (VT). The weekly training intensity distribution for POL was 75% of Z1 and 25% of Z3; HIIT was 100% of Z3 and THR was 50% of Z1 and 50% of Z2. Each group underwent Bruce protocol testing and supramaximal testing before, during, and after the intervention; relevant CRF parameters were assessed. 8 weeks of POL and HIIT significantly increased VT2 (p < 0.05); 8 weeks of POL, HIIT, THR and significantly increased VO2max and TTE (p < 0.05). The effect size of POL in relation to VO2max and TTE improvements was greater than that of HIIT and THR (g = 2.67 vs. 1.26 and 1.49; g = 2.75 vs. 2.05 and 1.60). Aerobic training models with different intensity distributions have different time effects on improving CRF. Relative to HIIT and THR, POL improved more variables of CRF. Therefore, POL is a feasible aerobic training method for improving CRF.

Resting heart rate is a population-level biomarker of cardiorespiratory fitness: The Fenland Study

INTRODUCTION

Few large studies have evaluated the relationship between resting heart rate (RHR) and cardiorespiratory fitness. Here we examine cross-sectional and longitudinal relationships between RHR and fitness, explore factors that influence these relationships, and demonstrate the utility of RHR for remote population monitoring.

METHODS

In cross-sectional analyses (The UK Fenland Study: 5,722 women, 5,143 men, aged 29-65y), we measured RHR (beats per min, bpm) while seated, supine, and during sleep. Fitness was estimated as maximal oxygen consumption (ml⋅min-1⋅kg-1) from an exercise test. Associations between RHR and fitness were evaluated while adjusting for age, sex, adiposity, and physical activity. In longitudinal analyses (6,589 participant subsample), we re-assessed RHR and fitness after a median of 6 years and evaluated the association between within-person change in RHR and fitness. During the coronavirus disease-2019 pandemic, we used a smartphone application to remotely and serially measure RHR (1,914 participant subsample, August 2020 to April 2021) and examined differences in RHR dynamics by pre-pandemic fitness level.

RESULTS

Mean RHR while seated, supine, and during sleep was 67, 64, and 57 bpm. Age-adjusted associations (beta coefficients) between RHR and fitness were -0.26, -0.29, and -0.21 ml⋅kg-1⋅beat-1 in women and -0.27, -0.31, and -0.19 ml⋅kg-1⋅beat-1 in men. Adjustment for adiposity and physical activity attenuated the RHR-to-fitness relationship by 10% and 50%, respectively. Longitudinally, a 1-bpm increase in supine RHR was associated with a 0.23 ml⋅min-1⋅kg-1 decrease in fitness. During the pandemic, RHR increased in those with low pre-pandemic fitness but was stable in others.

CONCLUSIONS

RHR is a valid population-level biomarker of cardiorespiratory fitness. Physical activity and adiposity attenuate the relationship between RHR and fitness.

Feasibility of Aerobic Exercise Training to Mitigate Cardiotoxicity of Breast Cancer Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

Current anticancer treatments for breast cancer (BC) may cause cardiotoxicity. This study aimed to investigate the effectiveness of aerobic exercise in mitigating cardiotoxicity caused by BC therapy.

MATERIALS AND METHODS

PubMed, Embase, Cochrane Library, Web of Science, and the Physiotherapy Evidence Database were searched until February 7, 2023. Clinical trials investigating the effectiveness of exercise training, including aerobic exercise, in BC patients receiving treatments that could cause cardiotoxicity were eligible. Outcome measures included cardiorespiratory fitness (CRF) (peak oxygen consumption, VO₂peak), left ventricular ejection fraction, and peak oxygen pulse. Intergroup differences were determined by standard mean differences (SMD) and 95% confidence intervals (CIs). Trial sequential analysis (TSA) was utilized to ensure whether the current evidence was conclusive.

RESULTS

Sixteen trials involving 876 participants were included. Aerobic exercise significantly improved CRF measured by VO₂peak in mL/kg/min (SMD 1.79, 95% CI 0.99-2.59) when compared to usual care. This result was confirmed through TSA. Subgroup analyses revealed that aerobic exercise given during BC therapy significantly improved VO₂peak (SMD 1.84, 95% CI 0.74-2.94). Exercise prescriptions at a frequency of up to 3 times per week, an intensity of moderate to vigorous, and a >30-minute session length also improved VO₂peak.

CONCLUSION

Aerobic exercise is effective in improving CRF when compared to usual care. Exercise performed up to 3 times per week, at a moderate-to-vigorous intensity, and having a session length >30 minutes is considered effective. Future high-quality research is needed to determine the effectiveness of exercise intervention in preventing cardiotoxicity caused by BC therapy.

Comparing Lifestyle Modifications and the Magnitude of Their Associated Benefit on Cancer Mortality

Many cancers are associated with poor diet, lack of physical activity, and excess weight. Improving any of these three lifestyle factors would likely reduce cancer deaths. However, modifications to each of these-better nutrition, enhanced activity and fitness, and loss of extra body fat-have different effect sizes on cancer mortality. This review will highlight the relative benefit that each lifestyle change, enacted prior to a diagnosis of cancer, might impart on cancer-related deaths, as well as attempt to quantify the changes required to derive such a benefit. The review relies primarily on epidemiological data, with meta-analyses serving as the backbone for comparisons across interventions and individual studies within the larger meta-analyses providing the data necessary to form more quantitative conclusions. The reader can then use this information to better understand, recommend, and implement behaviors that might ultimately reduce cancer mortality. Of all the interventions, it seems clear that exercise, specifically improving cardiorespiratory fitness, is the best way to decrease the risk of dying from cancer.

Factors Associated with Cardiorespiratory Fitness in Breast Cancer Survivors from the State of Santa Catarina, Brazil: Cross-Sectional Study

Introduction: Oxygen consumption (VO2) is indicative of cardiorespiratory fitness (CRF) and lower levels are related to a higher risk of total mortality among individuals with cancer whose therapy can have adverse consequences on the cardiovascular system. Objective: To examine the associations of patient-reported sociodemographic, clinical, anthropometric outcomes and functional variables with CRF in 69 women (55±10 years) and to identify whether walking is a predictor of peak VO2 variation in this population with breast cancer (BC). Method: Female BC survivors receiving hormone therapy after two types of surgery (breast-conserving and mastectomy) underwent a CRF test on a cycle ergometer to measure peak VO2. A questionnaire containing sociodemographic, clinical data, patient reported outcomes (PROs) (depressive symptoms, sleep quality, fatigue, body image) and self-reported walking and tests to measure body fat percentage, waist circumference, flexibility and shoulder range of motion (RoM) were performed. Results: Unemployment and retirement were associated with low CRF, as was the use of aromatase inhibitors instead of tamoxifen. Depressive symptoms, worse body image, greater waist circumference, less flexibility and shoulder RoM were also associated with low CRF. Walking duration, controlled for age and body mass index (BMI), is a 13% predictor of peak VO2 variance in this sample. Conclusion: These factors must be considered in understanding the CRF profile of BC survivors. As walking was a predictor of peak VO2 variance, it should be recommended as a type of physical activity for patients with BC using hormone therapy.

Physical Activity and Cardiorespiratory Fitness as Modulators of Health Outcomes: A Compelling Research-Based Case Presented to the Medical Community

The beneficial health effects and prognostic significance of regular moderate-to-vigorous physical activity (PA), increased cardiorespiratory fitness (CRF), or both are often underappreciated by the medical community and the patients they serve. Individuals with low CRF have higher annual health care costs, higher rates of surgical complications, and are two to three times more likely to die prematurely than their fitter counterparts when matched for risk factor profile or coronary calcium score. Increased levels of habitual PA before hospitalization for acute coronary syndromes are also associated with better short-term cardiovascular outcomes. Accordingly, this review examines these relations and the potential underlying mechanisms of benefit (eg, exercise preconditioning), with specific reference to the incidence of cardiovascular, cancer, and coronavirus diseases, and the prescriptive implications and exercise thresholds for optimizing health outcomes. To assess the evidence supporting or refuting the benefits of PA and CRF, we performed a literature search (PubMed) and critically reviewed the evidence to date. In aggregate, these data are presented in the context of clarifying the impact that regular PA and/or increased CRF have on preventing and treating chronic and infectious diseases, with reference to evidence-based exercise thresholds that the medical community can embrace and promote.

Impaired aerobic capacity in adolescents and young adults after treatment for cancer or non-malignant haematological disease

PURPOSE

Childhood cancer survivors are at increased risk for cardiovascular disease. Maximal oxygen uptake (VO_2max) is a major determinant of cardiovascular morbidity. The aim of this study was to compare aerobic capacity, measured by cardiopulmonary exercise test (CPET), of adolescents and young adults in remission with that of healthy controls and to identify the predictors of aerobic capacity in this population.

METHOD

This is a controlled cross-sectional study.

RESULTS

A total of 477 subjects (77 in remission and 400 controls), aged from 6 to 25 years, were included, with a mean delay between end of treatment and CPET of 2.9 ± 2.3 years in the remission group. In this group, the mean VO_2max was significantly lower than in controls (37.3 ± 7.6 vs. 43.3 ± 13.1 mL/kg/min, P < 0.01, respectively), without any clinical or echocardiographic evidence of heart failure. The VAT was significantly lower in the remission group (26.9 ± 6.0 mL/kg/min vs. 31.0 ± 9.9 mL/kg/min, P < 0.01, respectively). A lower VO_2max was associated with female sex, older age, higher BMI, radiotherapy, and hematopoietic stem cell transplantation.

CONCLUSION

Impaired aerobic capacity had a higher prevalence in adolescents and young adults in cancer remission. This impairment was primarily related to physical deconditioning and not to heart failure.

TRIAL REGISTRY

NCT04815447.

IMPACT

In childhood cancer survivors, aerobic capacity is five times more impaired than in healthy subjects. This impairment mostly reflects early onset of physical deconditioning. No evidence of heart failure was observed in this population.

Metabolic Health, Mitochondrial Fitness, Physical Activity, and Cancer

Cancer continues to be a significant global health issue. Traditional genetic-based approaches to understanding and treating cancer have had limited success. Researchers are increasingly exploring the impact of the environment, specifically inflammation and metabolism, on cancer development. Examining the role of mitochondria in this context is crucial for understanding the connections between metabolic health, physical activity, and cancer. This study aimed to review the literature on this topic through a comprehensive narrative review of various databases including MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. The review highlighted the importance of mitochondrial function in overall health and in regulating key events in cancer development, such as apoptosis. The concept of "mitochondrial fitness" emphasizes the crucial role of mitochondria in cell metabolism, particularly their oxidative functions, and how proper function can prevent replication errors and regulate apoptosis. Engaging in high-energy-demanding movement, such as exercise, is a powerful intervention for improving mitochondrial function and increasing resistance to environmental stressors. These findings support the significance of considering the role of the environment, specifically inflammation and metabolism, in cancer development and treatment. Further research is required to fully understand the mechanisms by which physical activity improves mitochondrial function and potentially reduces the risk of cancer.

Epidemiological, mechanistic, and practical bases for assessment of cardiorespiratory fitness and muscle status in adults in healthcare settings

Given their importance in predicting clinical outcomes, cardiorespiratory fitness (CRF) and muscle status can be considered new vital signs. However, they are not routinely evaluated in healthcare settings. Here, we present a comprehensive review of the epidemiological, mechanistic, and practical bases of the evaluation of CRF and muscle status in adults in primary healthcare settings. We highlight the importance of CRF and muscle status as predictors of morbidity and mortality, focusing on their association with cardiovascular and metabolic outcomes. Notably, adults in the best quartile of CRF and muscle status have as low as one-fourth the risk of developing some of the most common chronic metabolic and cardiovascular diseases than those in the poorest quartile. The physiological mechanisms that underlie these epidemiological associations are addressed. These mechanisms include the fact that both CRF and muscle status reflect an integrative response to the body function. Indeed, muscle plays an active role in the development of many diseases by regulating the body's metabolic rate and releasing myokines, which modulate metabolic and cardiovascular functions. We also go over the most relevant techniques for assessing peak oxygen uptake as a surrogate of CRF and muscle strength, mass, and quality as surrogates of muscle status in adults. Finally, a clinical case of a middle-aged adult is discussed to integrate and summarize the practical aspects of the information presented throughout. Their clinical importance, the ease with which we can assess CRF and muscle status using affordable techniques, and the availability of reference values, justify their routine evaluation in adults across primary healthcare settings.

Subjective Gait Speed and Risk of Developing Cardiovascular Events in 56,589 Cancer Survivors

Despite having a higher risk of cardiovascular disease (CVD), there are currently limited data for stratifying CVD risk among cancer survivors. The purpose of this study was to uncover the relationship of subjective gait speed with incident CVD among cancer survivors.This retrospective observational cohort study analyzed data from the JMDC Claims Database between 2005 and 2021 including 56,589 patients with a prior history of breast, colorectal, or stomach cancer but no history of CVD. Gait speed was evaluated using information from self-reported questionnaires collected during health checkups. The primary endpoint was composite CVD outcome, which included heart failure, myocardial infarction, angina pectoris, and stroke.The median (interquartile range) age was 54 (48-61) years, and 20,981 (37.1%) were male. Among them, 25,933 patients (45.8%) reported fast gait speed. During a mean follow-up period of 1002 ± 803 days, 3,221 composite CVD outcomes were recorded. In multivariate Cox regression analysis, slow gait speed was associated with a higher risk of developing CVD compared with fast gait speed (hazard ratio, 1.14, 95% confidence interval, 1.06-1.22). This association was consistent across a variety of sensitivity analyses.We demonstrated that subjective slow gait speed was associated with a greater risk of CVD development among cancer survivors. This suggests the potential value of gait speed assessment for the CVD risk stratification of cancer patients as well as the clinical importance of maintaining exercise capacity among patients living with cancer.

Effects of a Clinical Exercise Program on Health-Related Fitness and Quality of Life in Spanish Cancer Patients Receiving Adjuvant Therapy

OBJECTIVE

To report the feasibility and effectiveness of a newly developed clinical exercise program for improving maximal cardiorespiratory fitness in Spanish cancer patients receiving adjuvant chemotherapy or radiation. We also examined the effectiveness of the exercise program for improving maximal muscular strength, body composition, fatigue, and quality of life, and explored if the effectiveness varied based on selected patient characteristics.

DESIGN

The study was a single group implementation feasibility study using a pre-posttest design.

METHODS

Participants performed a 12-week, twice-weekly, supervised, multi-component exercise program during adjuvant therapy. Paired t-tests were used to assess pre-post changes, and analyses of covariance were used to compare effectiveness based on selected patient characteristics.

RESULTS

We had 100 cancer patients referred to the clinical exercise program of which 85 (85%) initiated the exercise program and 76 (89%) completed the post-intervention fitness assessment. Exercise significantly improved VO_2max by 4.8 mL/kg/minutes (P < .001, d = 0.74). Exercise also significantly improved chest strength (P < .001, d = 0.82), leg strength (P < .001, d = 1.27), lean body mass (P < .001, d = 0.11), skeletal muscle mass (P < .001; d = 0.09), fat mass (P < .001; d = 0.10), % body fat (P < .001; d = 0.17), quality of life (P = .0017; d = 0.41), and fatigue (P = .007; d = 0.46). Treatment modality, cancer type, and age affected some exercise responses, especially related to body composition changes.

CONCLUSIONS

A 12-week, supervised, multi-component exercise program was effective for improving health-related fitness and quality of life in Spanish cancer patients receiving adjuvant therapy. Our results show the benefits of incorporating clinical exercise programming into the supportive care of cancer patients receiving treatments.

REGISTRATION

The study protocol is registered at ClinicalTrials.gov (NCT05078216).

C-Reactive Protein Is Associated with Physical Fitness in Breast Cancer Survivors

Background: Physical fitness (PF) is an expression of the physiological functioning of multiple body components. PF is an important prognostic factor in terms of cardiovascular mortality, cancer mortality, and all-cause mortality. PF has been related to some biomarkers in the general population but not in breast cancer survivors (BCS). Purpose: To evaluate the effects of PF on biomarkers potentially related to physical activity (PA) in a sample of BCS. Methods: Cross-sectional study. A total of 84 BCS (mean age 54) who had finished their treatment were recruited. Different components of PF were evaluated, namely body composition (anthropometry), cardiorespiratory fitness (one-mile walk test), muscular (handgrip and sit-to-stand timed test), and motor (gait speed) components. Sexual hormones, inflammation, and insulin resistance biomarkers were measured. Results: C-Reactive Protein (CRP) was associated with every component of physical fitness: cardiorespiratory fitness (p-value = 0.002), muscular (sit-to-stand timed test, p-value = 0.002) and motor (gait speed, p-value = 0.004) components, and body composition (body mass index, p-value = 0.003; waist, p-value < 0.000; and waist-to-hip index, p-value = 0.012). CRP also was associated with “poor physical condition,” a constructed variable that encompasses all components of physical fitness (p-value < 0.001). Insulin was associated with cardiorespiratory fitness and gait speed (p-values = 0.002 and 0.024, respectively). Insulin-like Growth Factor-1 was negatively associated with waist perimeter and waist-to-hip ratio. Conclusions: CRP can also be considered an indicator of poor PF in BCS. Implications for cancer survivors: in case of elevation of CRP indicating cardiovascular risk, health professionals should recommend lifestyle changes to improve BCS physical condition.

Longitudinal cardio-respiratory fitness prediction through wearables in free-living environments

Cardiorespiratory fitness is an established predictor of metabolic disease and mortality. Fitness is directly measured as maximal oxygen consumption (VO2max), or indirectly assessed using heart rate responses to standard exercise tests. However, such testing is costly and burdensome because it requires specialized equipment such as treadmills and oxygen masks, limiting its utility. Modern wearables capture dynamic real-world data which could improve fitness prediction. In this work, we design algorithms and models that convert raw wearable sensor data into cardiorespiratory fitness estimates. We validate these estimates' ability to capture fitness profiles in free-living conditions using the Fenland Study (N=11,059), along with its longitudinal cohort (N = 2675), and a third external cohort using the UK Biobank Validation Study (N = 181) who underwent maximal VO2max testing, the gold standard measurement of fitness. Our results show that the combination of wearables and other biomarkers as inputs to neural networks yields a strong correlation to ground truth in a holdout sample (r = 0.82, 95CI 0.80-0.83), outperforming other approaches and models and detects fitness change over time (e.g., after 7 years). We also show how the model's latent space can be used for fitness-aware patient subtyping paving the way to scalable interventions and personalized trial recruitment. These results demonstrate the value of wearables for fitness estimation that today can be measured only with laboratory tests.

Effectiveness of HIIT in patients with cancer or cancer survivors: An umbrella and mapping review with meta-meta-analysis

OBJECTIVE

To assess the available evidence on the effectiveness of high-intensity interval training (HIIT) in addition to first-choice cancer treatment on cardiorespiratory fitness (CRF), quality of life (QoL), adherence, and adverse effects of HIIT in patients with cancer or cancer survivors.

METHODS

An umbrella review and meta-meta-analysis (MMA) was performed. A systematic search was conducted in MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science until August 2021. Article selection, quality assessment, and risk of bias assessment were performed by two independent reviewers. The MMA were performed with a random-effects model and the summary statistics were presented in the form of forest plot with a weighted compilation of all standardized mean differences (SMD) and corresponding 95% confidence interval (CI).

RESULTS

Seven systematic reviews were included. Regarding CRF, the addition of HIIT to cancer treatment showed statistically significant differences with a small clinical effect, compared with adding other treatments (SMD = 0.45; 95% CI 0.24 to 0.65). There was no significant difference when compared with adding moderate-intensity continuous training (MICT) (SMD = 0.23; 95% CI -0.04 to 0.50). QoL showed positive results although with some controversy. Adherence to HIIT intervention was high, ranging from 54% to 100%. Regarding adverse effects, most of the systematic reviews reported none, and in the cases in which they occurred, they were mild.

CONCLUSION

In conjunction with first-choice cancer treatment, HIIT has been shown to be an effective intervention in terms of CRF and QoL, as well as having optimal adherence rate. In addition, the implementation of HIIT in patients with cancer or cancer survivors is safe as it showed no or few adverse effects.

Cardiopulmonary and muscular effects of different doses of high-intensity physical training in substance use disorder patients: study protocol for a block allocated controlled endurance and strength training trial in an inpatient setting

INTRODUCTION

Patients with substance use disorder (SUD) have high prevalence of lifestyle-related comorbidities. Physical exercise is known to yield substantial prophylactic impact on disease and premature mortality, and there seems to be an inverse association between physical fitness and adverse health outcomes. High-intensity training is regarded as most effective for improving physical fitness, but less is known concerning the ideal training dose necessary to achieve clinically relevant effects in these patients. The aim of this study is to compare the effect of low-dose and high-dose, high-intensity training, on physical fitness in patients diagnosed with SUD.

METHODS AND ANALYSIS

This study will recruit 40 in-patients of mixed genders, aged 18-70 years. Participants will be block allocated to low-dose or high-dose training, encompassing 24 high-intensity interval and maximal strength training sessions (3/week × 8 weeks). After a 10 min warm-up, the low-dose group will perform 1×4 min intervals at ⁓90% of maximal heart rate and 2×4 repetitions strength training at ⁓90% of 1 repetition maximum. The high-dose group will perform 4×4 min intervals at ⁓90% of maximal heart rate and 4×4 repetitions strength training at ⁓90% of 1 repetition maximum. Clinical measurements and physical tests will be conducted at baseline, midway and on completion and a questionnaire on physical activity will be administered at baseline.

ETHICS AND DISSEMINATION

This protocol is in accordance with the Standard Protocol Items: Recommendations for Interventional Trials statement. All participants will sign a written informed consent. The Regional Committee of Medical Research Ethics, Norway has approved the study. A study of this kind is warranted, and the results will be published in an open access journal to ensure public access, and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT04065334.

Cardiorespiratory fitness, white blood cell count, and mortality in men and women

BACKGROUND

We examined the associations of cardiorespiratory fitness (CRF) and white blood cell count (WBC) with mortality outcomes.

METHODS

A total of 52,056 apparently healthy adults completed a comprehensive health examination, including a maximal treadmill test and blood chemistry analyses. CRF was categorized as high, moderate, or low by age and sex; WBC was categorized as sex-specific quartiles.

RESULTS

During 17.8 ± 9.5 years (mean ± SD) of follow-up, a total of 4088 deaths occurred. When regressed jointly, significantly decreased all-cause mortality across CRF categories was observed within each quartile of WBC in men. Within WBC Quartile 1, all-cause mortality hazard ratios (HRs) with a 95% confidence interval (95%CI) were 1.0 (referent), 1.29 (95%CI: 1.06‒1.57), and 2.03 (95%CI: 1.42‒2.92) for high, moderate, and low CRF categories, respectively (p for trend < 0.001). Similar trends were observed in the remaining 3 quartiles. With the exception of cardiovascular disease (CVD) mortality within Quartile 1 (p for trend = 0.743), there were also similar trends across CRF categories within WBC quartiles in men for both CVD and cancer mortality (p for trend < 0.01 for all). For women, there were no significant trends across CRF categories for mortality outcomes within Quartiles 1-3. However, we observed significantly decreased all-cause mortality across CRF categories within WBC Quartile 4 (HR = 1.05 (95%CI: 0.76‒1.44), HR = 1.63 (95%CI:1.20‒2.21), and HR = 1.87 (95%CI:1.29‒2.69) for high, moderate, and low CRF, respectively (p for trend = 0.002)). Similar trends in women were observed for CVD and cancer mortality within WBC Quartile 4 only.

CONCLUSION

There are strong joint associations between CRF, WBC, and all-cause, CVD, and cancer mortality in men; these associations are less consistent in women.