Strenuous Exercise and Cardiovascular Disease Outcomes

Oxygen uptake efficiency plateau is unaffected by fitness level - the NOODLE study

BACKGROUND

Endurance athletes (EA) are an emerging population of focus for cardiovascular health. The oxygen uptake efficiency plateau (OUEP) is the levelling-off period of ratio between oxygen uptake (VO2) and ventilation (VE). In the cohort of EA, we externally validated prediction models for OUEP and derived with internal validation a new equation.

METHODS

140 EA underwent a medical assessment and maximal cycling cardiopulmonary exercise test. Participants were 55% male (N = 77, age = 21.4 ± 4.8 years, BMI = 22.6 ± 1.7 kg·m- 2, peak VO2 = 4.40 ± 0.64 L·min- 1) and 45% female (N = 63, age = 23.4 ± 4.3 years, BMI = 22.1 ± 1.6 kg·m- 2, peak VO2 = 3.21 ± 0.48 L·min- 1). OUEP was defined as the highest 90-second continuous value of the ratio between VO2 and VE. We used the multivariable stepwise linear regression to develop a new prediction equation for OUEP.

RESULTS

OUEP was 44.2 ± 4.2 mL·L- 1 and 41.0 ± 4.8 mL·L- 1 for males and females, respectively. In external validation, OUEP was comparable to directly measured and did not differ significantly. The prediction error for males was - 0.42 mL·L- 1 (0.94%, p = 0.39), and for females was + 0.33 mL·L- 1 (0.81%, p = 0.59). The developed new prediction equation was: 61.37-0.12·height (in cm) + 5.08 (for males). The developed model outperformed the previous. However, the equation explained up to 12.9% of the variance (R = 0.377, R2 = 0.129, RMSE = 4.39 mL·L- 1).

CONCLUSION

OUEP is a stable and transferable cardiorespiratory index. OUEP is minimally affected by fitness level and demographic factors. The predicted OUEP provided promising but limited accuracy among EA. The derived new model is tailored for EA. OUEP could be used to stratify the cardiorespiratory response to exercise and guide training.

The effects of a multi-day cross-country mountain bike race on myocardial function, stress, inflammation and cardiac biomarkers in amateur master athletes

This study aimed to examine the effects of a multi-day mountain bike race on amateur master athlete cyclists (AMA). AMA (50±5 years) completed 2 stages of a mountain bike race. Six weeks before racing, echocardiography, blood and maximal cardiopulmonary exercise tests (CPET) were performed. One hour after completion of each race stage, echocardiography measurements were taken and blood was sampled for stress, inflammatory and cardiac biomarkers. Main outcomes of the CPET were maximal oxygen consumption (VO2max) 50.7±6.5 ml/kg/min; maximal power 328±45 Watt and ventilatory threshold of 86%VO2max. Participants completed 95.7km with an elevation of 1650m on the first day, and 92.5km with an elevation of 1410m on the second day, with completion times of 357±42 and 390 ±43 minutes, respectively. After racing, increases in Creatine Phosphokinase and C-reactive protein (3-6 fold) (p<0.001), Troponin I (4-fold) (p<0.001) and N-terminal pro-brain natriuretic peptide (NT-Pro BNP) (4-7-fold) (p<0.001) were noted, with a reduction in the myocardial global work index of 17-24% (p<0.001). No correlations were found between Troponin I or NT-Pro BNP and myocardial global work index. Highly aerobically fit AMA participating in demanding endurance events demonstrated elevated stress, inflammatory, muscle damage and cardiac biomarkers. However, these changes did not significantly correlate with altered cardiac function. In addition, consecutive days of demanding prolonged cycling exercise did not have cumulative effects on the measured myocardial parameters.

Is the Ventilatory Efficiency in Endurance Athletes Different?-Findings from the NOODLE Study

Background: Ventilatory efficiency (VE/VCO2) is a strong predictor of cardiovascular diseases and defines individuals' responses to exercise. Its characteristics among endurance athletes (EA) remain understudied. In a cohort of EA, we aimed to (1) investigate the relationship between different methods of calculation of VE/VCO2 and (2) externally validate prediction equations for VE/VCO2. Methods: In total, 140 EA (55% males; age = 22.7 ± 4.6 yrs; BMI = 22.6 ± 1.7 kg·m-2; peak oxygen uptake = 3.86 ± 0.82 L·min-1) underwent an effort-limited cycling cardiopulmonary exercise test. VE/VCO2 was first calculated to ventilatory threshold (VE/VCO2-slope), as the lowest 30-s average (VE/VCO2-Nadir) and from whole exercises (VE/VCO2-Total). Twelve prediction equations for VE/VCO2-slope were externally validated. Results: VE/VCO2-slope was higher in females than males (27.7 ± 2.6 vs. 26.1 ± 2.0, p < 0.001). Measuring methods for VE/VCO2 differed significantly in males and females. VE/VCO2 increased in EA with age independently from its type or sex (β = 0.066-0.127). Eleven equations underestimated VE/VCO2-slope (from -0.5 to -3.6). One equation overestimated VE/VCO2-slope (+0.2). Predicted and observed measurements differed significantly in nine models. Models explained a low amount of variance in the VE/VCO2-slope (R2 = 0.003-0.031). Conclusions: VE/VCO2-slope, VE/VCO2-Nadir, and VE/VCO2-Total were significantly different in EA. Prediction equations for the VE/VCO2-slope were inaccurate in EA. Physicians should be acknowledged to properly assess cardiorespiratory fitness in EA.

Deletion allele of Apo B gene is associated with higher inflammation, oxidative stress and dyslipidemia in obese type 2 diabetic patients: an analytical cross-sectional study

BACKGROUND

We decided to compare some inflammatory, and oxidative stress markers, as well as lipid profiles between the obese and non-obese patients with type 2 diabetes considering ApoB gene polymorphism.

METHODS

one-hundred sixty two patients with type 2 diabetes were included in this study. ApoB genotyping was conducted by the polymerase chain reaction. Serum interleukin-(IL-18), pentraxin-3 (PTX-3), and high sensitive- C reactive protein (hs-CRP) was measured as the inflammatory markers. Moreover, copper-zinc superoxide dismutase (Cu/Zn-SOD), total antioxidant capacity (TAC) and 8-isoprostane F2α were analyzed for oxidative stress assessment. Anthropometric indices and lipid profiles were measured.

RESULTS

Adjusted for confounders, serum hs-CRP (p = 0.04), LDL-C (p = 0.01), LDL-C/HDL-C (p = 0.04), and TG (p = 0.02) were significantly lower at the Homozygous Insertion (Ins)/Ins vs. deletion (Del) allele carriers in the obese patients. Serum TAC was significantly lower at the obese Del allele carriers than Ins/Ins Homozygous (p = 0.03). Serum hs-CRP (p = 0.006), and 8-IsoprostanF2α (P = 0.04) were significantly higher in the obese Del allele carriers than non-obese. Serum Cu/Zn-SOD was significantly higher in the non-obese Del allele carriers than obese (p = 0.04).

CONCLUSION

Inflammation, dyslipidemia, and oxidative stress are higher in the Obese Del allele carriers with type 2 diabetes which prone them to other chronic disorders.

Musculoskeletal modeling and humanoid control of robots based on human gait data

The emergence of exoskeleton rehabilitation training has brought good news to patients with limb dysfunction. Rehabilitation robots are used to assist patients with limb rehabilitation training and play an essential role in promoting the patient's sports function with limb disease restoring to daily life. In order to improve the rehabilitation treatment, various studies based on human dynamics and motion mechanisms are still being conducted to create more effective rehabilitation training. In this paper, considering the human biological musculoskeletal dynamics model, a humanoid control of robots based on human gait data collected from normal human gait movements with OpenSim is investigated. First, the establishment of the musculoskeletal model in OpenSim, inverse kinematics, and inverse dynamics are introduced. Second, accurate human-like motion analysis on the three-dimensional motion data obtained in these processes is discussed. Finally, a classic PD control method combined with the characteristics of the human motion mechanism is proposed. The method takes the angle values calculated by the inverse kinematics of the musculoskeletal model as a benchmark, then uses MATLAB to verify the simulation of the lower extremity exoskeleton robot. The simulation results show that the flexibility and followability of the method improves the safety and effectiveness of the lower limb rehabilitation exoskeleton robot for rehabilitation training. The value of this paper is also to provide theoretical and data support for the anthropomorphic control of the rehabilitation exoskeleton robot in the future.

Spontaneous Atrial Fibrillation in Transgenic Goats With TGF (Transforming Growth Factor)-β1 Induced Atrial Myopathy With Endurance Exercise

BACKGROUND

There is increasing evidence that endurance exercise is associated with increased risk of atrial fibrillation (AF). However, it is unknown if the relationship between endurance exercise and AF is dependent on an atrial myopathy.

METHODS

Six cardiac-specific TGF (transforming growth factor)-β1 transgenic and 6 wild-type (WT) goats were utilized for these studies. Pacemakers were implanted in all animals for continuous arrhythmia monitoring and AF inducibility. AF inducibility was evaluated using 5 separate 10 s bursts of atrial pacing (160-200 ms). Three months of progressive endurance exercise (up to 90 minutes at 4.5 mph) was performed. Quantitative assessment of circulating microRNAs and inflammatory biomarkers was performed.

RESULTS

Sustained AF (≥30 s) was induced with 10 s of atrial pacing in 4 out of 6 transgenic goats compared with 0 out of 6 WT controls at baseline (P<0.05). No spontaneous AF was observed at baseline. Interestingly, between 2 and 3 months of exercise 3 out of 6 transgenic animals developed self-terminating spontaneous AF compared with 0 out of 6 WT animals (P<0.05). There was an increase in AF inducibility in both transgenic and WT animals during the first 2 months of exercise with partial normalization at 3 months (transgenic 67%; 100%; 83% versus WT 0%; 67%; 17%). These changes in AF susceptibility were associated with a decrease in circulating microRNA-21 and microRNA-29 during the first 2 months of exercise with partial normalization at 3 months in both transgenic and WT animals. Finally, MMP9 (matrix metallopeptidase 9) was increased during the second and third months of exercise training.

CONCLUSIONS

This study demonstrates a novel transgenic goat model of cardiac fibrosis (TGF-β1 overexpression) to demonstrate that endurance exercise in the setting of an underlying atrial myopathy increases the incidence of spontaneous AF. Furthermore, endurance exercise seems to increase inducible AF secondary to altered expression of key profibrotic biomarkers that is independent of the presence of an atrial myopathy.

A Systematic Review Comparing Dose Response of Exercise on Cardiovascular and All-Cause Mortality

It is well established that exercise improves cardiovascular and all-cause mortality, although an ideal dose of exercise is not known. The physical activity guidelines currently recommend 150 minutes per week of moderate-intensity exercise or 75 minutes of vigorous-intensity activity. Most individuals do not engage in adequate exercise, although a safe upper limit does not exist and a too much exercise hypothesis has recently emerged. This review of the literature analyzes studies that have evaluated exercise dose response on all-cause and cardiovascular mortality for the purpose of determining safe and effective exercise prescriptions. Searches were performed in PubMed and CINAHL between 2010 and 2018 to identify six studies that met inclusion criteria. Moderate-intensity exercise reduced all-cause mortality in five of six studies, whereas low-dose exercise most effectively improved all-cause mortality in three studies, and cardiovascular mortality in one study. Vigorous-intensity exercise or extreme doses demonstrated variable outcomes and remain controversial; two studies found vigorous-intensity exercise beneficial to improve health, two studies discouraged vigorous exercise, and two studies had less conclusive outcomes. It is not surprising that any amount of exercise improves health compared with none at all, with the greatest benefits observed when sedentary individuals began exercising. Low-dose exercise should be recommended to everyone with a goal of meeting the minimal requirements according to guidelines for decreased all-cause and cardiovascular mortality. Additional research to more thoroughly understand exercise dose response and motivate individuals to improve exercise engagement is currently warranted.

Cardiac Risk of Extreme Exercise

Habitual moderate intensity exercise is a vital component of a healthy lifestyle. For most of the population, increasing exercise duration and intensity beyond current recommendations appears to impart additional cardiovascular benefits; however, recent data has raised the possibility of an inflection point after which additional exercise no longer imparts benefit and may even result in negative cardiovascular outcomes. Exercise at the extremes of human endurance places a large hemodynamic stress on the heart and results in occasionally profound cardiac remodeling in order to accommodate the huge increases in cardiac output demanded by such endeavors. These changes have the potential to become maladaptive and heighten the risk of various arrhythmias, influence the rate of coronary atherosclerosis, and alter the risk of sudden cardiac death. Herein, we will discuss the potential negative impact of extreme exercise on cardiovascular risk.

Mountain Cycling Ultramarathon Effects on Inflammatory and Hemoglobin Responses

PURPOSE

This study aimed to analyze the cumulative physiological burden of repetitive, strenuous exercise held during mountain cycling ultramarathon on regulatory mechanisms of hemoglobin degradation.

METHODS

Fifty-five nonprofessional athletes (mean age, 44.8 ± 7.1 yr) participating in a 9-consecutive-day mountain cycling ultramarathon (TransPortugal) underwent anthropometric, hematological, and biochemical assessments before and immediately after the race. Participants were further stratified as completers (nine courses) or noncompleters and were divided according to the time they took to complete the race. The heme oxygenase-1 (HMOX1) functional genetic polymorphism and haptoglobin (HP) phenotypic variants were also analyzed.

RESULTS

Total leukocytes, neutrophil count, and monocyte count increased, whereas decreases in erythrocyte counts and hemoglobin were found between pre- and postultramarathon. Circulating haptoglobin (Hp) was increased, whereas its soluble receptor (sCD163) decreased. Athletes who completed all nine courses presented with increased leukocyte, neutrophil, and erythrocyte counts, as well as hemoglobin, red cell distribution width, total bilirubin, and total cholesterol levels. High-sensitivity C-reactive protein and Hp decreased in comparison with noncompleters. HMOX1 and HP genetic polymorphisms were associated with biochemical profile, notably with Hp levels. Analysis of covariance showed a significant effect of HP phenotype in Hp circulating levels at the end of race and on the magnitude of variation from pre- to postrace.

CONCLUSIONS

Present findings support a comodulatory influence of genetic- and exercise-associated factors on resulting inflammatory and hemoglobin catabolic marker Hp after highly demanding endurance exercise.

Mortality and health-related habits in 900 Finnish former elite athletes and their brothers

BACKGROUND

There is conflicting evidence on the associations between participation in vigorous sports, health habits, familial factors and subsequent mortality. We investigated all-cause mortality and health-related behaviour among former elite athletes and their brothers.

METHODS

The mortality of Finnish male former elite athletes, who had represented Finland between 1920 and 1965 (n=900) and their age-matched brothers (n=900), was followed from the time when athlete started an elite athlete career until 31 December 2015. The age-adjusted HRs were calculated by a paired Cox proportional hazards model. In 2001, surviving participants (n=199 athletes and n=199 age-matched brothers) reported their self-rated health (SRH), physical activity, alcohol consumption and smoking habits in the questionnaire.

RESULTS

During the total follow-up period, 1296 deaths (72% of the cohort) occurred. The age-adjusted HRs for all-cause mortality in former athletes was 0.75 (95% CI 0.65 to 0.87, P<0.001) compared with their age-matched brothers. Median age at death was 79.9 years for endurance, 75.9 years for mixed sports and 72.2 years for power sports athletes, and 77.5, 73.7 and 72.2 years for their age-matched brothers, respectively. In 2001, compared with their brothers, former athletes smoked less (P<0.001), were more physically active (P<0.05) and rated their health more often as very good (P<0.05).

CONCLUSIONS

Former elite athletes are more physically active, smoke less, have better self-rated health and live longer than their brothers. Genetic differences between athletes and brothers, aerobic training for endurance elite sports and a healthier lifestyle may all contribute to reduced mortality.