A specific prediction equation is necessary to estimate peak oxygen uptake in obese patients with metabolic syndrome

Comparison of Cardiorespiratory Fitness Prediction Equations and Generation of New Predictive Model for Patients with Obesity

PURPOSE

Cardiorespiratory fitness (CRF) is a critical marker of overall health and a key predictor of morbidity and mortality, but the existing prediction equations for CRF are primarily derived from general populations and may not be suitable for patients with obesity.

METHODS

Predicted CRF from different non-exercise prediction equations was compared with measured CRF of patients with obesity who underwent maximal cardiopulmonary exercise testing (CPET). Multiple linear regression was used to develop a population-specific nonexercise CRF prediction model for treadmill exercise including age, sex, weight, height, and physical activity level as determinants.

RESULTS

Six hundred sixty patients underwent CPET during the study period. Within the entire cohort, R2 values had a range of 0.24 to 0.46. Predicted CRF was statistically different from measured CRF for 19 of the 21 included equations. Only 50% of patients were correctly classified into the measured CRF categories according to predicted CRF. A multiple model for CRF prediction (mL·min -1 ) was generated ( R2 = 0.78) and validated using two cross-validation methods.

CONCLUSIONS

Most used equations provide inaccurate estimates of CRF in patients with obesity, particularly in cases of severe obesity and low CRF. Therefore, a new prediction equation was developed and validated specifically for patients with obesity, offering a more precise tool for clinical CPET interpretation and risk stratification in this population.

Reference Standards of Cardiorespiratory Fitness Measured With the Cardiopulmonary Exercise Test Using the Treadmill in Chinese Adults Younger Than 60 Years

PURPOSE

Cardiorespiratory fitness (CRF) is a strong predictor of cardiorespiratory diseases and varies by race. The purpose of this study was to provide CRF reference standards and a prediction equation for peak oxygen uptake (V˙O 2peak ) from treadmill-based cardiopulmonary exercise testing (CPX) in Chinese individuals.

METHODS

Healthy participants (n = 4199) who completed a CPX using a treadmill were studied. The percentiles of V˙O 2peak were determined for four age groups (decades). A regression prediction model was developed from the derivation cohort (n = 3361), validated in the independent validation cohort (n = 838), and compared with the widely used Wasserman equation and the Fitness Registry and the Importance of Exercise National Database (FRIEND) equation.

RESULTS

The mean V˙O 2peak values of four age groups (20-29, 30-39, 40-49, and 50-59 yr) were 42.6, 41.2, 38.7, and 35.9 mL/kg/min, respectively, for men, and 37.1, 34.7, 32.0, and 30.3 mL/kg/min, respectively, for women. The 50th percentiles of relative V˙O 2peak decreased with age for both sexes. The prediction equation was: Absolute V˙O 2peak (mL/min) = 236.68 - (504.64 × sex [male = 0; female = 1]) + (21.23× weight [kg]) - (14.31 × age [yr]) + (9.46 × height [cm]) (standard error of the estimate = 379.59 mL/min, R2 = 0.66, P < .001).Percentage predicted V˙O 2peak for the validation sample was 100.2%. The novel equation performed better than the other two equations.

CONCLUSION

This study reports the first CRF reference standards and prediction equation generated from treadmill CPX in China. These reference standards provide a framework for interpreting the CRF of the Chinese population and could be useful information for a global CRF database.

Evaluation of a Supervised Adapted Physical Activity Program Associated or Not with Oral Supplementation with Arginine and Leucine in Subjects with Obesity and Metabolic Syndrome: A Randomized Controlled Trial

Background: In patients with obesity and metabolic syndrome (MetS), lifestyle interventions combining diet, in particular, and physical exercise are recommended as the first line treatment. Previous studies have suggested that leucine or arginine supplementation may have beneficial effects on the body composition or insulin sensitivity and endothelial function, respectively. We thus conducted a randomized controlled study to evaluate the effects of a supervised adapted physical activity program associated or not with oral supplementation with leucine and arginine in MetS-complicated patients with obesity. Methods: Seventy-nine patients with obesity and MetS were randomized in four groups: patients receiving arginine and leucine supplementation (ALs group, n = 20), patients on a supervised adapted physical activity program (APA group, n = 20), patients combining ALs and APA (ALs+APA group, n = 20), and a control group (n = 19). After the baseline evaluation (m0), patients received ALs and/or followed the APA program for 6 months (m6). Body composition, MetS parameters, lipid and glucose metabolism markers, inflammatory markers, and a cardiopulmonary exercise test (CPET) were assessed at m0, m6, and after a 3-month wash-out period (m9). Results: After 6 months of intervention, we did not observe variable changes in body weight, body composition, lipid and glucose metabolism markers, inflammatory parameters, or quality of life scores between the four groups. However, during the CPET, the maximal power (Pmax and Ppeak), power, and O2 consumption at the ventilatory threshold (P(VT) and O2(VT)) were improved in the APA and ALs+APA groups (p < 0.05), as well as the forced vital capacity (FVC). Between m6 and m9, a gain in fat mass was only observed in patients in the APA and ALs+APA groups. Conclusion: In our randomized controlled trial, arginine and leucine supplementation failed to improve MetS in patients with obesity, as did the supervised adapted physical activity program and the combination of both. Only the cardiorespiratory parameters were improved by exercise training.

Validity of Estimated Cardiorespiratory Fitness in Patients With Primary Breast Cancer

Background

Estimated peak oxygen consumption (Vo₂peak) is widely used in oncology; however, estimated Vo₂peak equations were developed in noncancer settings.

Objectives

The aim of this study was to evaluate the validity of estimated Vo₂peak in women with primary breast cancer and to develop oncology-specific estimated Vo₂peak equations.

Methods

Vo₂peak was directly measured (TrueOne 2400, Parvo Medics) during 380 cardiopulmonary exercise tests in women previously treated for breast cancer (mean age: 59 ± 10 years; 3.1 ± 1.2 years post-therapy). The American College of Sports Medicine (ACSM), the Fitness Registry and the Importance of Exercise National Database (FRIEND), and heart failure (HF)-FRIEND equations were used to estimate Vo₂peak. New equations were developed using patient and peak (Onc_peak) or submaximal (Onc_sub) exercise test characteristics.

Results

The median differences between measured and estimated Vo₂peak were 7.0 mL O₂·kg⁻¹·min⁻¹, 3.9 mL O₂·kg⁻¹·min⁻¹, and −0.2 mL O₂·kg⁻¹·min⁻¹ for ACSM, FRIEND, and HF-FRIEND, respectively. The number of estimated Vo₂peak values within ±3.5 mL O₂·kg⁻¹·min⁻¹ of the measured values was 70 (18%), 164 (43%), and 306 (81%) for ACSM, FRIEND, and HF-FRIEND, respectively. The Onc_peak and Onc_Sub models included body mass index, age, a history of chemotherapy or radiation, the peak measured heart rate, and the treadmill grade and/or speed. The median differences between measured and estimated Vo₂peak were 0.02 mL O₂·kg⁻¹·min⁻¹ (Onc_peak) and −0.2 mL O₂·kg⁻¹·min⁻¹ (Onc_sub). Eighty-six percent (n = 325) and 76% (n = 283) estimated Vo₂peak values were within ±3.5 mL O₂·kg⁻¹·min⁻¹ of the measured Vo₂peak values for Onc_peak and Onc_sub, respectively.

Conclusions

HF-FRIEND or oncology-specific equations could be applied to estimate Vo₂peak in patients previously treated for breast cancer in settings where cardiopulmonary exercise tests are not available. (Trial Comparing the Effects of Linear Versus Nonlinear Aerobic Training in Women With Operable Breast Cancer [EXCITE]; NCT01186367

Factors influencing participation in educational workshops as part of a pulmonary rehabilitation program in patients with chronic obstructive pulmonary disease: a retrospective study

BACKGROUND

Pulmonary rehabilitation (PR) (primarily composed of an exercise training program (ET) and educational workshops) is an effective intervention for patients with chronic obstructive pulmonary disease. Although factors which influence participation in the full PR program have been reported, specific data on the educational component of PR have not been published. We aimed to identify factors which predict refusal to participate in the educational component of PR.

RESEARCH DESIGN AND METHODS

201 patient charts were retrospectively included in the analysis. Patients were classified according to their acceptance or refusal to participate in the educational workshops.

RESULTS

The location of ET outside the center was independently related to refusal to participate in the educational workshops (OR = 0.01 [95%CI 0.00 to 0.17]). Patients who refused the workshops were less disabled according to the number of prescriptions of noninvasive ventilation, use of medical transport, oxygen consumption and workload achieved during cardiopulmonary exercise testing.

CONCLUSIONS

The location of exercise sessions during PR influences patients' decisions to refuse or accept center-based educational workshops. When center-based PR programs are limited, and the ET is relocated to the patient's home, the educational workshops should also be relocated.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (NCT04301245).

Cardiopulmonary Exercise Testing to Assess Persistent Symptoms at 6 Months in People With COVID-19 Who Survived Hospitalization: A Pilot Study

OBJECTIVE

The aim of this pilot study was to assess physical fitness and its relationship with functional dyspnea in survivors of COVID-19 6 months after their discharge from the hospital.

METHODS

Data collected routinely from people referred for cardiopulmonary exercise testing (CPET) following hospitalization for COVID-19 were retrospectively analyzed. Persistent dyspnea was assessed using the modified Medical Research Council dyspnea scale.

RESULTS

Twenty-three people with persistent symptoms were referred for CPET. Mean modified Medical Research Council dyspnea score was 1 (SD = 1) and was significantly associated with peak oxygen uptake (VO2peak; %) (rho = -0.49). At 6 months, those hospitalized in the general ward had a relatively preserved VO2peak (87% [SD = 20]), whereas those who had been in the intensive care unit had a moderately reduced VO2peak (77% [SD = 15]). Of note, the results of the CPET revealed that, in all individuals, respiratory equivalents were high, power-to-weight ratios were low, and those who had been in the intensive care unit had a relatively low ventilatory efficiency (mean VE/VCO2 slope = 34 [SD = 5]). Analysis of each individual showed that none had a breathing reserve <15% or 11 L/min, all had a normal exercise electrocardiogram, and 4 had a heart rate >90%.

CONCLUSION

At 6 months, persistent dyspnea was associated with reduced physical fitness. This study offers initial insights into the mid-term physical fitness of people who required hospitalization for COVID-19. It also provides novel pathophysiological clues about the underlaying mechanism of the physical limitations associated with persistent dyspnea. Those with persistent dyspnea should be offered a tailored rehabilitation intervention, which should probably include muscle reconditioning, breathing retraining, and perhaps respiratory muscle training.

IMPACT

This study is the first, to our knowledge, to show that a persistent breathing disorder (in addition to muscle deconditioning) can explain persistent symptoms 6 months after hospitalization for COVID-19 infection and suggests that a specific rehabilitation intervention is warranted.

Similarity between predicted and obtained oxygen consumption during incremental cardiopulmonary exercise test in healthy men and chronic heart failure patients

ABSTRACT Cardiopulmonary exercise testing (CPX) is a noninvasive method for assessing physiological changes during physical exercise. Functional capacity has been evaluated using prediction equations. However, this evaluation method may yield different outcomes when applied to a healthy male population and patients with chronic heart failure (HF). This study aimed to compare the estimated and obtained values of oxygen consumption (VO2) during CPX both at the ventilatory anaerobic threshold (VAT) and at peak exercise for healthy men and HF patients. For that, 56 men were divided into 3 groups: (1) 18 young and healthy (YG) (27±6.01 years); (2) 14 healthy older adults (OG) (61±6.3 years); and (3) 24 chronic HF patients (HFG) (53±13.6 years). CPX in cycle ergometer was administered to all individuals for determining VO2 at the VAT and peak exercise. Then, VO2 was estimated at the two moments using a prediction equation, and estimated values were compared to those obtained. Estimated VO2 was significantly higher than obtained VO2 in OG (16.9±1.8 vs. 13.1±2.1mL/kg/min) and HFG (12±6.9 vs. 8.7±2.5mL/kg/min). We found no difference between estimated and obtained VO2 for the YG (22,6±5,5 vs. 23,1±8,7mL/kg/min). The prediction equation overestimated VO2 values for older adults and HF patients. However, the YG obtained similar values than those estimated.

Asthaxanthin Improves Aerobic Exercise Recovery Without Affecting Heat Tolerance in Humans

Objectives: To examine the supplementation effects of the xanthophyll carotenoid Astaxanthin on physical performance and exertional heat strain in humans.

Design: A randomized double blind placebo controlled trial.

Methods: Twenty two male participants (Age: 23.14 ± 3.5 y, height: 175 ± 6 cm, body mass: 69.6 ± 8.7 kg, % body fat: 16.8 ± 3.8) received placebo (PLA, n = 10) or Astaxanthin (ATX, n = 12) 12 mg/day Per os (P.O), for 30 days, and were tested pre and post-supplementation with a maximal oxygen uptake (VO₂ Max) test and the heat tolerance test (HTT) (2 h walk at 40°C, 40% relative humidity (RH), 5 kph, 2% incline). NIH database registration no. NCT02088242. Gas exchange, Heart rate (HR), Relative perceived exertion (RPE), and blood lactate were measured during the VO₂ Max test. Heart rate (HR), rectal (Trec), and skin (Tskin) temperatures, RPE, and sweat rate (SR) were monitored in the HTT. Serum heat shock protein 72 (HSP72), Creatine phospho-kinase (CPK), C-reactive protein (CRP), and lipid profile were measured before and after the test.

Results: The rise in blood lactate caused by the VO₂ Max test was significantly diminished in the ATX group (9.4 ± 3.1 and 13.0 ± 3.1 mmole^*l⁻¹ in the ATX and PLA groups, respectively P < 0.02), as was the change in oxygen uptake during recovery (−2.02 ± 0.64 and 0.83 ± 0.79% of VO₂ Max in the ATX and PLA group, respectively, p = 0.001). No significant differences were observed in the anaerobic threshold or VO₂ Max. In the HTT, no significant physiological or biochemical differences were observed (HR <120 bpm, Trec rose by ~1°C to <38°C, no difference in SR).

Conclusions: Astaxanthin supplementation improved exercise recovery. No benefit was observed for ATX over PLA in response to heat stress. Further examination of Astaxanthin in higher exertional heat strain is required.

Validity of maximal oxygen consumption prediction equations in young Saudi females

OBJECTIVES

To determine the applicability of Jones, Hansen, and Wasserman predictive equations for maximal oxygen consumption (VO2max) in Saudi females.  Methods: This cross-sectional study was conducted at Imam Abdulrahman Bin Faisal University, Dammam, Kingdom of Saudi Arabia, between March and May 2017. Maximal oxygen consumption was measured directly through the COSMED system for cardiopulmonary exercise testing in 102 girls with normal body mass index (19-25 years old). Maximal oxygen consumption was indirectly predicted by Jones, Hansen, and Wasserman equations. Paired t-test, Pearson correlation, and Bland-Altman plot were used for comparison, correlation, and agreement analysis. Results: The difference between the mean and standard deviation (±SD) VO2max values of the direct measurement (27.39±4.06 ml/kg-1/min-1), and the Jones (35.19±2.12 ml/kg-1/min-1), Hansen (33.64±0.24 ml/kg-1/min-1), and Wasserman (35.20±0.17 ml/kg-1/min-1) equations, was statistically significant (p less than 0.001). Bland-Altman plot analysis suggested a lack of agreement between direct and predicted VO2max. Pearson correlation failed to reveal any correlation between direct VO2max and VO2max calculated with any of the 3 equations. Conclusion: Jones, Hansen, and Wasserman equations for prediction of VO2max cannot be justified in the studied population. For the better prediction of VO2max, either these equations should be modified, or a new equation should be developed for the Saudi population.

Benefits of a regular vs irregular rhythm-based training programme on physical fitness and motor skills in obese girls

PURPOSE

The aim of the current study was to examine the impact of a physical exercise programme including rhythmic elements (regular and irregular tempos) on physiological variables, motor skills (MS), and jump performances in obese girls.

METHODS

Thirty-six obese girls (age: 10.4 ± 0.9 years, body mass: 58.7 ± 4.0 kg, height: 1.37 ± 0.04 m, body mass index: 31.2 ± 2.1) participated in three weekly physical exercise sessions for 6 weeks, with each session consisting of basic fundamental locomotor movements. The participants were divided into two groups: a control group (CG) and an experimental group (EG). CG performed the exercise in a quiet setting (i.e., without rhythmic accompaniment), whereas regular and irregular rhythmic accompaniments were prescribed in EG. The physical exercise programme included three sessions per week for 6 weeks. Each session was composed of three parts: 15 min of warm-up, followed by 40 min of exercises based on basic locomotor movements (i.e., running, hopping, skipping, jumping, leaping, sliding, galloping, throwing, catching, kicking, dribbling, and striking) and then 5 min of stretching. Each exercise was demonstrated by the teacher. Before and after the intervention period, cardiovascular measures (i.e., resting blood pressures, recovery for heart rate and systolic blood pressure, and recovery rate-pressure product) were made and five MS (i.e., running, hopping, leaping, jumping and dribbling) were evaluated in two conditions (i.e., during exercise with regular and irregular tempos). Moreover, performances on vertical jump tests (squat and countermovement jump tests) were measured.

RESULTS

EG exhibited greater improvement in MS with a regular tempo (and sometimes an irregular tempo), cardiovascular components, and jump performances.

CONCLUSION

These findings demonstrate that physical exercise at various tempos is useful for improving physical fitness, developing MS, and thus probably preventing obesity complications.

Sport and male sexuality

The relationships between sport and sexuality in males are of great social and clinical interest, because of sports and motor activities that highly promote social and sexual relationships. Even if few literature exist, two main questions should be taken into account: whether and how physical exercise and sport positively or negatively influence sexual health and behavior and/or whether and how sexual behavior may affect a sub-sequent sport performance. Physical exercise and sport per se can influence, positively or negatively, the hypothalamic-pituitary-testicular axis function and, consequently, the individual's reproductive and/or sexual health. This depends on individual factors such as genetic and epigenetic ones and on different variables involved in the practice of sport activities (type of sport, intensity and duration of training, doping and drug use and abuse, nutrition, supplements, psychological stress, allostatic load, etc.). If well conducted, motor and sport activities could have beneficial effects on sexual health in males. Among different lifestyle changes, influencing sexual health, regular physical activity is fundamental to antagonize the onset of erectile dysfunction (ED). However, competitive sport can lead both reproductive and/or sexual tract damages and dysfunctions, transient (genital pain, hypoesthesia of the genitalia, hypogonadism, DE, altered sexual drive, etc.) or permanent (hypogonadism, DE, etc.), by acting directly (traumas of the external genitalia, saddle-related disorders in cyclists, etc.) or indirectly (exercise-related hypogonadism, drug abuse, doping, stress, etc.). Sexual activities shortly performed before a sport competition could differently influence sport performance. Due to the few existing data, it is advisable to avoid an absolute pre-competition sexual abstinence.