Successful 10-second one-legged stance performance predicts survival in middle-aged and older individuals.

OBJECTIVES: Balance quickly diminishes after the mid-50s increasing the risk for falls and other adverse health outcomes. Our aim was to assess whether the ability to complete a 10- s one-legged stance (10-second OLS) is associated with all-cause mortality and whether it adds relevant prognostic information beyond ordinary demographic, anthropometric and clinical data. METHODS: Anthropometric, clinical and vital status and 10-s OLS data were assessed in 1702 individuals (68% men) aged 51-75 years between 2008 and 2020. Log-rank and Cox modelling were used to compare survival curves and risk of death according to ability (YES) or inability (NO) to complete the 10-s OLS test. RESULTS: Overall, 20.4% of the individuals were classified as NO. During a median follow-up of 7 years, 7.2% died, with 4.6% (YES) and 17.5% (NO) on the 10-s OLS. Survival curves were worse for NO 10-s OLS (log-rank test=85.6; p<0.001). In an adjusted model incorporating age, sex, body mass index and comorbidities, the HR of all-cause mortality was higher (1.84 (95% CI: 1.23 to 2.78) (p<0.001)) for NO individuals. Adding 10-s OLS to a model containing established risk factors was associated with significantly improved mortality risk prediction as measured by differences in -2 log likelihood and integrated discrimination improvement. CONCLUSIONS: Within the limitations of uncontrolled variables such as recent history of falls and physical activity, the ability to successfully complete the 10-s OLS is independently associated with all-cause mortality and adds relevant prognostic information beyond age, sex and several other anthropometric and clinical variables. There is potential benefit to including the 10-s OLS as part of routine physical examination in middle-aged and older adults.

Physical activity and risk of venous thromboembolism: systematic review and meta-analysis of prospective cohort studies.

The inverse association between physical activity and arterial thrombotic disease is well established. Evidence on the association between physical activity and venous thromboembolism (VTE) is divergent. We conducted a systematic review and meta-analysis of published observational prospective cohort studies evaluating the associations of physical activity with VTE risk. MEDLINE, Embase, Web of Science, and manual search of relevant bibliographies were systematically searched until 26 February 2019. Extracted relative risks (RRs) with 95% confidence intervals (CIs) for the maximum versus minimal amount of physical activity groups were pooled using random effects meta-analysis. Twelve articles based on 14 unique prospective cohort studies comprising of 1,286,295 participants and 23,753 VTE events were eligible. The pooled fully-adjusted RR (95% CI) of VTE comparing the most physically active versus the least physically active groups was 0.87 (0.79-0.95). In pooled analysis of 10 studies (288,043 participants and 7069 VTE events) that reported risk estimates not adjusted for body mass index (BMI), the RR (95% CI) of VTE was 0.81 (0.70-0.93). The associations did not vary by geographical location, age, sex, BMI, and methodological quality of studies. There was no evidence of publication bias among contributing studies. Pooled observational prospective cohort studies support an association between regular physical activity and low incidence of VTE. The relationship does not appear to be mediated or confounded by BMI.

Association between cardiorespiratory fitness, obesity, and health care costs: The Veterans Exercise Testing Study.

BACKGROUND/OBJECTIVE: Obesity is a chronic disease, a risk factor for other chronic conditions and for early mortality, and is associated with higher health care utilization. Annual spending among obese individuals is at least 30% higher vs. that for normal-weight peers. In contrast, higher cardiorespiratory fitness (CRF) is related to many health benefits. We sought to examine the association between CRF and health care costs across the spectrum of body mass index (BMI). METHODS: Data from 3,924 men (58.1 ± 11.1 years, 29.2 ± 5.3 kg.m-2) who completed a maximal exercise test for clinical reasons and to estimate CRF were recorded prospectively at the time of testing. Cost data (USD) from each subject during a 6-year period after the exercise test were merged with the exercise database and compared according to BMI and estimated CRF (CRFe). Subjects were categorized as normal-weight (BMI < 25.0 kg.m-2), overweight (BMI 25.0-29.9 kg.m-2), and obese (BMI ≥ 30.0 kg.m-2). We also formed four CRFe categories based on age-stratified quartiles of metabolic equivalents (METs) achieved: least-fit (5.1 ± 1.5 METs; n = 1,044), moderately-fit (7.6 ± 1.5 METs; n = 938), fit (9.4 ± 1.5 METs; n = 988), and highly-fit (12.4 ± 2.2 METs; n = 954). RESULTS: Average annual costs per person adjusted for age and presence of cardiovascular disease were $37,018, $40,572, and $45,683 for normal-weight, overweight, and obese subjects, respectively (p < 0.01). For each 1-MET incremental increase in CRFe, annual cost savings per person were $3,272, $4,252, and $6,103 for normal-weight, overweight, and obese subjects, respectively. Stratified by CRFe categories, annual costs for normal-weight, overweight, and obese subjects in the highest CRFe quartile were $28,028, $31,669, and $32,807 lower, respectively, compared to subjects in the lowest CRFe quartile (p < 0.01). CONCLUSION: Higher CRFe is associated with lower health care costs. Cost savings were particularly evident in obese subjects, suggesting that the economic burden of obesity may be reduced through interventions that target improvements in CRF.

Women Have Lower Mortality Than Men After Attending a Long-Term Medically Supervised Exercise Program.

PURPOSE: Medically supervised exercise programs (MSEPs) are equally recommended for men and women with cardiovascular disease (CVD). Aware of the lower CVD mortality in women, we hypothesized that among patients attending a MSEP, women would also have better survival. METHODS: Data from men and women, who were enrolled in a MSEP between 1994 and 2018, were retrospectively analyzed. Sessions included aerobic, resistance, flexibility and balance exercises, and cardiopulmonary exercise test was performed. Date and underlying cause of death were obtained. Kaplan-Meier methods and Cox proportional hazards regression were used for survival analysis. RESULTS: A total of 2236 participants (66% men, age range 33-85 yr) attended a median of 52 (18, 172) exercise sessions, and 23% died during 11 (6, 16) yr of follow-up. In both sexes, CVD was the leading cause of death (39%). Overall, women had a more favorable clinical profile and a longer survival compared to men (HR = 0.71: 95% CI, 0.58-0.85; P < .01). When considering those with coronary artery disease and similar clinical profile, although women had a lower percentage of sex- and age-predicted maximal oxygen uptake at baseline than men (58 vs 78%; P < .01), after adjusting for age, women still had a better long-term survival (HR = 0.68: 95% CI, 0.49-0.93; P = .02). CONCLUSION: Survival after attendance to a long-term MSEP was better among women, despite lower baseline cardiorespiratory fitness. Future studies should address whether men and women would similarly benefit when participating in an MSEP.

Variability of cardio-respiratory, electromyographic, and perceived exertion responses at the walk-run transition in a sample of young men controlled for anthropometric and fitness characteristics.

The cardio-respiratory (heart rate, HR; oxygen uptake, VO(2;) expired carbon dioxide, VCO(2); ventilation, VE), electromyographic (EMG; medial gastrocnemius, vastus lateralis, rectus femoralis, and anterior tibialis), and perceived exertion (PE) responses during a protocol for the determination of the walk-run transition speed (WRTS) were investigated. From an initial sample of 453 volunteers, 12 subjects matched for age, anthropometric characteristics [height, weight, lower limb length (LLL)], cardio-respiratory fitness (peak oxygen consumption, VO(2peak); ventilatory threshold, VT; maximal HR), and habitual physical activity levels were selected (age = 18.6 ± 0.5 years; height = 174.5 ± 1.4 cm; weight = 66.4 ± 1.1 kg; LLL = 83.3 ± 1.2 cm, VO(2peak) = 52.2 ± 2.2 ml kg(-1) min(-1); VT = 39.8 ± 2.6 ml kg(-1) min(-1)). The highly reproducible WRTS determination protocol (ICC = 0.92; p < 0.0001) consisted in 2-min warm-up at 5.5 km h(-1) followed by increments of 0.1 km h(-1) every 15 s. Between-subjects variability of the measured variables during 24 walking and 12 running velocities (from 80 to 120% of WRTS) was compared to WRTS variation. The coefficient of variation for WRTS was 7.8%, which was within the range of variability for age, anthropometric variables, VO(2peak), and maximal HR (from 5 to 12%). Cardio-respiratory responses at WRTS had a greater variation (VO(2) about 50%; VE/VCO(2) about 35%; VE/VO(2) about 45%; HR about 30%). The highest variation was found for PE (from 70 to 90%) whereas EMG variables showed the lowest variation (from 25 to 30%). Linear regression between EMG series and VO(2) data showed that VO(2) reflected the increase in muscle activity only before the WRTS. These results support the hypothesis that the walk-run transition phenomenon is determined by mechanical variables such as limb length and its relationship to biomechanical model rather than by metabolic factors.

Cardiorespiratory optimal point during exercise testing and sudden cardiac death: A prospective cohort study.

BACKGROUND: Cardiorespiratory optimal point (COP) during exercise, a potentially useful submaximal cardiopulmonary exercise testing (CPET) variable, may be an independent risk factor for cardiovascular disease outcomes. However, the relationship of COP with risk of sudden cardiac death (SCD) has not been previously investigated. We sought to evaluate the association between COP during exercise and SCD risk and determine whether COP improves SCD risk prediction. METHODS: COP, the minimum value of the ventilatory equivalent for oxygen (VE/VO2) in a given minute of a CPET, was ascertained in 2190 men who underwent clinical exercise testing. Hazard ratios (HRs) (95% confidence intervals [CIs]) and measures of risk discrimination for SCD were calculated. RESULTS: A total of 240 SCDs death occurred during a median follow-up of 28.8 years. COP was linearly associated with SCD in a dose-response manner. In a multivariable model comprising several established and emerging CVD risk factors, the HR (95% CI) for SCD was 2.51 (1.36-4.62) per standard deviation increase in COP. This was minimally attenuated to 2.36 (1.27-4.37) on further adjustment for high sensitivity C-reactive protein. The association did not vary importantly in several relevant clinical subgroups. Addition of COP to a SCD risk score was associated with a C-index change of 0.0086 (0.0005 to 0.0167; p = .038) and difference in -2 log likelihood (p = .017). CONCLUSIONS: COP during exercise is strongly, inversely and independently associated with SCD in a graded fashion. COP during exercise may potentially be used for the prediction of the long-term risk for SCD beyond established CVD risk factors.

Cardiac arrhythmias triggered by sudden and dynamic efforts.

BACKGROUND: Some arrhythmias are triggered only during exercise. The aim of this study is to describe the frequency and type of arrhythmia induced by a standardized protocol of sudden and dynamic exercise, which tends to reflect routine situations of efforts (e.g., climbing stairs), and compare with those found on maximal cardiopulmonary exercise test (CPET). METHODS: A total of 2329 subjects (1594 men) aged 9-91 years (mean 52 years, SD +/- 16) were submitted to a standardized protocol of sudden and dynamic exercise (4-second exercise test [4sET]) prior to a CPET. A continuous digital electrocardiogram (ECG) was recorded during 4sET and CPET, and later reviewed and interpreted by the same physician (who supervised all the procedures). RESULTS: A total of 1125 subjects (43%) had cardiac arrhythmias during one or both procedures. About 57% of the arrhythmias were supraventricular, but 47 subjects (2% of all subjects) presented more complex arrhythmias including 43 cases of nonsustained supraventricular tachycardia and four nonsustained ventricular tachycardia. While arrhythmias were more often exposed by the CPET (P < 0.01), in 221 cases (10% of the total sample) of arrhythmias they were only induced by 4sET; these included four cases of nonsustained supraventricular tachycardia. CONCLUSION: 4sET-induced arrhythmias tend to be simple and were always short-lasting. In some cases, ECG recording during 4sET showed arrhythmias that would not be induced by a progressive maximal exercise test. Different situations of exercise, sudden and short versus maximal and progressive, tend to generate different arrhythmic responses and possibly complementary clinical implications.

Cardiac vagal withdrawal and reactivation during repeated rest-exercise transitions.

It is not known whether subjects that have higher cardiac vagal reactivation (CVR) during repeated exercise transitions also have higher cardiac vagal withdrawal (CVW) at the onset of exercise, which would lead to better heart rate (HR) regulation during exercise transitions. Therefore, our aims were to investigate: (a) the influence of CVR on CVW during repeated rest-exercise transitions; and (b) the influence of the sympathetic activity on CVR and CVW. Fifty-eight healthy men (22 ± 4 years) performed 20 rest-exercise transitions interspaced by 30 s. In addition, nine healthy men (24 ± 3 years) ingested either 25 mg of atenolol or placebo, on a crossover, double-blind, randomized design, then performed 20 rest-exercise transitions interspaced by 30 s. Cardiac vagal reactivation was assessed by a HR variability index (RMSSD) and CVW by the HR increase at the onset of a valid and reliable cycling protocol. The CVR and CVW responses were associated (partial r ranged from 0.60 to 0.66; p < 0.05). Participants with higher CVR over transitions maintained their CVW over repeated transitions [first transition (mean ± SEM) = 1.59 ± 0.04 vs. 20th = 1.50 ± 0.03 (a.u.), p = 0.24], while participants with lower CVR had a CVW decrease over repeated transitions [first transition (mean ± SEM) = 1.38 ± 0.04 vs. 20th = 1.19 ± 0.03 (a.u.), p < 0.01). In addition, the CVR and CVW over the rest-exercise transitions were similar during atenolol and placebo (ANCOVA interaction p = 0.12 and p = 0.48, respectively). In conclusion, the CVR among repeated rest-exercise transitions influenced the CVW at the onset of exercise, which was not affected by a partial ß(1) cardioselective adrenoceptor blockade.

Effect of muscle mass on muscle mechanoreflex-mediated heart rate increase at the onset of dynamic exercise.

This study was conducted to determine whether the heart rate increase at the onset of passive dynamic exercise is related to the amount of skeletal muscle mass engaged in movement. Fifteen healthy male subjects, 18-30 years old, performed, from the 4th to the 8th second of a 12-s apnea, four different 4-s bouts of passive cycling assigned in a counterbalanced order, each one different from the others by the number of limbs engaged in the movement (i.e., 1 arm, 2 arms, 2 arms + 1 leg and 2 arms + 2 legs), while respiratory movements and limb muscle electromyography were recorded. A repeated-measures ANOVA showed that the RR interval at the end of 4-s passive cycling was reduced in all the four different bouts (P < 0.05); the variations (delta values from pre-exercise to the end of 4 s of passive cycling) were directly related, in a non-linear trend, to the amount of muscle mass engaged in movement. These variations were more expressive when extremes were compared (110 +/- 16 vs. 184 +/- 24 ms, respectively, 1 limb vs. 4 limbs, P < 0.05), with differences observed from the first cardiac cycle after the onset of exercise. It was concluded that in healthy subjects, heart rate increase at the onset of passive cycling is directly related to the number of limbs and consequently the amount of muscle mass engaged, which is possibly related to a greater afferent input from stretch-sensitive muscle mechanoreceptors.

Handgrip strength is inversely associated with fatal cardiovascular and all-cause mortality events.

Purpose: We aimed to assess the associations of handgrip strength (HS) with cardiovascular and all-cause mortality and whether adding data on HS to cardiovascular disease (CVD) risk factors is associated with improvement in CVD mortality prediction.Design: Handgrip strength was assessed in a population-based sample of 861 participants aged 61-74 years at baseline. Relative HS was obtained by dividing the absolute value by body weight.Results: During a median (interquartile range) follow-up of 17.3 (12.6-18.4) years, 116 fatal coronary heart diseases (CHDs), 195 fatal CVDs and 412 all-cause mortality events occurred. On adjustment for several risk factors, the hazard ratios (95% confidence intervals (CIs)) for fatal CHD, fatal CVD and all-cause mortality were 0.59 (0.37-0.95), 0.59 (0.41-0.86) and 0.66 (0.51-0.84), respectively, comparing extreme tertiles of relative HS. Adding relative HS to a CVD mortality risk prediction model containing established risk factors did not improve discrimination or reclassification using Harrell's C-index (C-index change: 0.0034; p = .65), integrated-discrimination-improvement (0.0059; p = .20) and net-reclassification-improvement (-1.31%; p = .74); however, there was a significant difference in -2 log likelihood (p < .001).Conclusions: Relative HS is inversely associated with CHD, CVD and all-cause mortality events. Adding relative HS to conventional risk factors improves CVD risk assessment using sensitive measures of discrimination.KEY MESSAGESHandgrip strength (HS) assessment is simple, inexpensive and it takes only a few minutes to measure in clinical practice; however, its prognostic role for fatal cardiovascular outcomes on top of traditional risk factors in apparently healthy populations is uncertain.In a population-based prospective cohort study, good HS adjusted for body weight was associated with lower risk of fatal cardiovascular outcomes and the associations remained consistent across several clinically relevant subgroups.Handgrip strength may be a useful prognostic tool for fatal CHD and CVD events, in the general population.

Effect of Beta-Blocker Use on Exercise Heart Rate Gradient and Reclassification of Mortality Risk in Patients Referred for Exercise Testing.

Impairments in heart rate (HR) reserve and HR recovery are associated with mortality, and the combination of these two, termed exercise HR gradient (EHRG), is a better predictor than either alone. However, the confounding effect of beta-blockade on chronotropic impairment to exercise has not been fully explored; the aim of the present study was to evaluate the effect of beta blockade on EHRG. Participants were 2769 Veterans (58.7 ± 11.6 years) who underwent a maximal exercise test for clinical reasons. HR reserve and HR recovery were acquired and divided into quintiles and summed to provide an EHRG score. Net reclassification improvement (NRI) was performed to evaluate the impact of HR reserve, HR recovery and EHRG on all-cause mortality for patients with and without beta-blocker use. During a mean follow up of 10.9 ± 4.1 years, 657 patients died. Among patients without beta-blocker therapy, adding EHRG score to an established model including multiple baseline risk factors and exercise capacity resulted in an NRI of 14.3% (p <0.001). Adding HR recovery instead of EHRG score yielded an NRI of 11.5% (p <0.001), whereas HR reserve had no significant NRI among patients without beta-blocker therapy. In contrast, among participants on beta-blocker therapy, the addition of HR reserve, HR recovery, or EHRG score did not result in any significant reclassification. In conclusion, EHRG was superior to both HR reserve and HR recovery in predicting mortality and provides significant reclassification of risk but only among patients not taking beta-blockers.

Maximal exercise oxygen pulse as a predictor of mortality among male veterans referred for exercise testing.

BACKGROUND: Maximal oxygen pulse (O(2) pulse) mirrors the stroke volume response to exercise, and should therefore be a strong predictor of mortality. Limited and conflicting data are, however, available on this issue. METHODS: Nine hundred forty-eight participants, classified as those with cardiopulmonary disease (CPD) and those without (non-CPD), underwent cardiopulmonary exercise testing (CPX) for clinical reasons between 1993 and 2003. The ability of maximal O(2) pulse and maximal oxygen uptake (peak VO(2)) to predict mortality was investigated using proportional hazards and Akaike information criterion analyses. All-cause mortality was the endpoint. RESULTS: Over a mean follow-up of 6.3+/-3.2 years, there were 126 deaths. Maximal O(2) pulse, expressed in either absolute or relative to age-predicted terms, and peak VO(2) were significant and independent predictors of mortality in those with and without CPD (P<0.04). Akaike information criterion analysis revealed that the model including both maximal O(2) pulse and peak VO(2) had the highest accuracy for predicting mortality. The optimal cut-points for O(2) pulse and peak VO(2) (<12; > or =12 ml/beat and <16; > or =16 ml/(kg.min) respectively) were established by the area under the receiver-operating-characteristic curve. The relative risks of mortality were 3.4 and 2.2 (CPD and non-CPD, respectively) among participants with both maximal O(2) pulse and peak VO(2) responses below these cut-points compared with participants with both responses above these cut-points. CONCLUSION: These results indicate that maximal O(2) pulse is a significant predictor of mortality in patients with and without CPD. The addition of absolute and relative O(2) pulse data provides complementary information for risk-stratifying heterogeneous participants referred for CPX and should be routinely included in the CPX report.

How often does spirometry testing induce cardiac arrhythmias?

AIMS: To describe the frequency and type of arrhythmia induced by forced expiratory and inspiratory flow-volume loop manoeuvres. METHODS: 735 subjects (548 men) aged from 10 to 98 years old (mean 54 years, SD +/- 15) were submitted to a conventional medical examination and spirometry testing prior to a maximal cardiopulmonary exercise test (CPET). A continuous digital electrocardiogram (ECG) was recorded during spirometry and CPET, and later reviewed and interpreted by the same physician (who supervised all the procedures). RESULTS: 470 subjects (64%) had cardiac arrhythmias during one or both procedures. About 60% of the arrhythmias were supraventricular, but 35 subjects (5%) presented more complex arrhythmias including frequent premature ventricular beats (n=31) or non-sustained ventricular tachycardia (n=4). While arrhythmias were more often exposed by the CPET (p<0.01), in 68 cases (10% of the total sample) arrhythmias were only induced by spirometry; these included four cases of non-sustained supraventricular tachycardia (n=4). CONCLUSIONS: Spirometry is a safe procedure with regard to induction of cardiac arrhythmias. Spirometry-induced arrhythmias tend to be simple and were always short-lasting. In some cases, ECG recording during spirometry showed arrhythmias that would not be induced by a progressive maximal exercise test.

Recovery from sauna bathing favorably modulates cardiac autonomic nervous system.

OBJECTIVE: Sauna bathing is becoming a common activity in many countries and it has been linked to favorable health outcomes. However, there is limited data on the heart rate (HR) and heart rate variability (HRV) responses to an acute sauna exposure. DESIGN: We conducted a single-group, longitudinal study utilizing a pre-post design to examine acute effects of sauna bathing on the autonomic nervous system as reflected by HRV. A total of 93 participants (mean [SD] age: 52.0 [8.8] years, 53.8% males) with cardiovascular risk factors were exposed to a single sauna session (duration: 30 min; temperature: 73 °C; humidity: 10-20%) and data on HRV variables were collected before, during and after sauna. RESULTS: Time and frequency-domain HRV variables were significantly modified (p < 0.001) by the single sauna session, with most of HRV variables tending to return near to baseline values after 30 min recovery. Resting HR was lower at the end of recovery (68/min) compared to pre-sauna (77/min). A sauna session transiently diminished the vagal component, whereas the cooling down period after sauna decreased low frequency power (p < 0.001) and increased high frequency power in HRV (p < 0.001), favorably modulating the autonomic nervous system balance. CONCLUSIONS: This study demonstrates that a session of sauna bathing induces an increase in HR. During the cooling down period from sauna bathing, HRV increased which indicates the dominant role of parasympathetic activity and decreased sympathetic activity of cardiac autonomic nervous system. Future randomized controlled studies are needed to show if HR and HRV changes underpins the long-term cardiovascular effects induced by regular sauna bathing.

Relative peak exercise oxygen pulse is related to sudden cardiac death, cardiovascular and all-cause mortality in middle-aged men.

Background Preliminary evidence suggests that peak exercise oxygen pulse - peak oxygen uptake/heart rate-, a variable obtained during maximal cardiopulmonary exercise testing and a surrogate of stroke volume, is a predictor of mortality. We aimed to assess the associations of peak exercise oxygen pulse with sudden cardiac death, fatal coronary heart disease and cardiovascular disease and all-cause mortality. Design A prospective study. Methods Peak exercise oxygen pulse was assessed in a maximal cycling test at baseline in 2227 middle-aged men of the Kuopio Ischaemic Heart Disease cohort study using expired gas variables and electrocardiograms. Relative peak exercise oxygen pulse was obtained by dividing the absolute value by body weight. Results During a median follow-up of 26.1 years 1097 subjects died; there were 220 sudden cardiac deaths, 336 fatal coronary heart diseases and 505 fatal cardiovascular diseases. Relative peak exercise oxygen pulse (mean 19.5 (4.1) mL per beat/kg/102) was approximately linearly associated with each outcome. Comparing extreme quartiles of relative peak exercise oxygen pulse, hazard ratios (95% confidence intervals) for sudden cardiac death, fatal coronary heart disease and cardiovascular disease, and all-cause mortality on adjustment for cardiovascular risk factors were 0.55 (0.36-0.83), 0.58 (0.42-0.81), 0.60 (0.46-0.79) and 0.59 (0.49-0.70), respectively ( P < 0.001 for all). The hazard ratios were unchanged on further adjustment for C-reactive protein and the use of beta-blockers. The addition of relative peak exercise oxygen pulse to a cardiovascular disease mortality risk prediction model significantly improved risk discrimination (C-index change 0.0112; P = 0.030). Conclusion Relative peak exercise oxygen pulse measured during maximal exercise was linearly and inversely associated with fatal cardiovascular and all-cause mortality events in middle-aged men. In addition, relative peak exercise oxygen pulse provided significant improvement in cardiovascular disease mortality risk assessment beyond conventional risk factors.

A reference equation for maximal aerobic power for treadmill and cycle ergometer exercise testing: Analysis from the FRIEND registry.

Background Maximal oxygen uptake (VO2max) is a powerful predictor of health outcomes. Valid and portable reference values are integral to interpreting measured VO2max; however, available reference standards lack validation and are specific to exercise mode. This study was undertaken to develop and validate a single equation for normal standards for VO2max for the treadmill or cycle ergometer in men and women. Methods Healthy individuals ( N = 10,881; 67.8% men, 20-85 years) who performed a maximal cardiopulmonary exercise test on either a treadmill or a cycle ergometer were studied. Of these, 7617 and 3264 individuals were randomly selected for development and validation of the equation, respectively. A Brazilian sample (1619 individuals) constituted a second validation cohort. The prediction equation was determined using multiple regression analysis, and comparisons were made with the widely-used Wasserman and European equations. Results Age, sex, weight, height and exercise mode were significant predictors of VO2max. The regression equation was: VO2max (ml kg-1 min-1) = 45.2 - 0.35*Age - 10.9*Sex (male = 1; female = 2) - 0.15*Weight (pounds) + 0.68*Height (inches) - 0.46*Exercise Mode (treadmill = 1; bike = 2) ( R = 0.79, R2 = 0.62, standard error of the estimate = 6.6 ml kg-1 min-1). Percentage predicted VO2max for the US and Brazilian validation cohorts were 102.8% and 95.8%, respectively. The new equation performed better than traditional equations, particularly among women and individuals ≥60 years old. Conclusion A combined equation was developed for normal standards for VO2max for different exercise modes derived from a US national registry. The equation provided a lower average error between measured and predicted VO2max than traditional equations even when applied to an independent cohort. Additional studies are needed to determine its portability.

High Cardiorespiratory Optimal Point Values Are Related to Cardiovascular Mortality in Men Aged 46 to 70 Years: a Prospective Cohort Study

Abstract Background: Several hemodynamic and respiratory variables measured during cardiopulmonary exercise testing (CPX) have been shown to predict survival. One such measure is the cardiorespiratory optimal point (COP) that reflects the best possible circulation-respiration interaction, but there are still limited data on its relationship with adverse outcomes. Objective: To assess the association between COP and cardiovascular mortality in men aged 46 to 70 years. Methods: A sample of 2201 men who had anthropometric, clinical, and COP data obtained during cycling CPX between 1995 and 2022 was extracted from the CLINIMEX Exercise cohort. COP was identified as the minimal minute-to-minute VE/VO2 during CPX. Vital data were censored on October 31, 2022 for ICD-10-identified cardiovascular deaths. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs). Results: The mean ± standard deviation age was 57 ± 6 years and the median COP value was 24 (interquartile range = 21.2 to 27.4). During a mean follow-up of 4688 ± 2416 days, 129 (5.6%) patients died from cardiovascular causes. The death rates for low (< 28), high (28 to 30), and very high (> 30) categories of COP were 3.2%, 9.6%, and 18.7%, respectively. Following adjustment for age, history of myocardial infarction, diagnosis of coronary artery disease, and diabetes mellitus, the HR (95% CI) for cardiovascular mortality comparing very high versus low COP was 2.76 (1.87 to 4.07; p < 0.001). Conclusions: Our data indicate that, for a general population-based sample of men, COP > 30 represents a considerably higher risk for cardiovascular death. Information on COP could assist cardiovascular risk assessment in men.

Age-related decline in handgrip strength differs according to gender.

It is well-established that at old age there is a significant decline in muscle strength. Reference values for muscle strength might be useful for assessment of muscle impairment and of physiological adaptations. However, it is still unclear whether gender affects the rate of decline. Therefore, the aim of this study is to investigate the effect of gender and age on handgrip strength and to establish reference values for this variable. Reviewing medical charts collected from 1994 to 2005, a convenience sample of 2,648 subjects (1,787 men and 861 women), aged between 18 and 90 years, was obtained. Our results show higher handgrip strength for men compared with women (36.8 +/- 0.20 vs. 21.0 +/- 0.18 kg; p < 0.001). The regression analysis with a quadratic model shows that aging accounts for 30% of the variance in handgrip strength (r(2) = 0.30; p < 0.001) in men and 28% (r(2) = 0.28; p < 0.001) in women. In addition, the bent linear regression with multiple regressors show that a faster decline in handgrip strength occurs at the age of 30 years for men and 50 years for women. We conclude that handgrip strength decline with age differs between genders, making useful the existence of distinct male and female normative age group data.

Cardiorespiratory optimal point during exercise testing as a predictor of all-cause mortality.

INTRODUCTION AND AIM: The cardiorespiratory optimal point (COP) is a novel index, calculated as the minimum oxygen ventilatory equivalent (VE/VO2) obtained during cardiopulmonary exercise testing (CPET). In this study we demonstrate the prognostic value of COP both independently and in combination with maximum oxygen consumption (VO2max) in community-dwelling adults. METHODS: Maximal cycle ergometer CPET was performed in 3331 adults (66% men) aged 40-85 years, healthy (18%) or with chronic disease (81%). COP cut-off values of <22, 22-30, and >30 were selected based on the log-rank test. Risk discrimination was assessed using COP as an independent predictor and combined with VO2max. RESULTS: Median follow-up was 6.4 years (7.1% mortality). Subjects with COP >30 demonstrated increased mortality compared to those with COP <22 (hazard ratio [HR] 6.86, 95% confidence interval [CI] 3.69-12.75, p<0.001). Multivariate analysis including gender, age, body mass index, and the forced expiratory volume in 1 s/vital capacity ratio showed adjusted HR for COP >30 of 3.72 (95% CI 1.98-6.98; p<0.001) and for COP 22-30 of 2.15 (95% CI 1.15-4.03, p<0.001). Combining COP and VO2max data further enhanced risk discrimination. CONCLUSIONS: COP >30, either independently or in combination with low VO2max, is a good predictor of all-cause mortality in community-dwelling adults (healthy or with chronic disease). COP is a submaximal prognostic index that is simple to obtain and adds to CPET assessment, especially for adults unable or unwilling to achieve maximal exercise.

Pre-Participation Physical Fitness does not Influence Adherence to a Supervised Exercise Program.

BACKGROUND: Exercise-based cardiac rehabilitation tends to reduce mortality. However, it requires medium/long-term adherence to regular physical exercise. It is relevant to identify the variables that affect adherence to an supervised exercise program (SEP). OBJECTIVE: To evaluate the influence of pre-participation levels of aerobic and non-aerobic physical fitness components in medium-term adherence to SEP. METHODS: A total of 567 SEP participants (65 ± 12 years) (68% men) were studied. Participants adherent to the program for less than 6 months (48%) (non-adherent - NAD) were compared with 52% of participants who were adherent for 6 months or more (adherents - AD). In the non-aerobic fitness, flexibility (FLX) (Flexitest) and muscle power (MPW)/body weight in standing rowing (watts/kg) were evaluated while aerobic fitness was obtained by direct measure of VO2max/body weight (VO2). These measurements were normatized for sex and age based on percentiles (P) (P-FLX/P-MPW) of reference data or percentages of predicted (P-VO2). Additionally, AD and NAD with extreme results (tertiles) were simultaneously compared for the three variables. RESULTS: There was no difference between AD and NAD for non-aerobic results, in median [P25-P75], P-FLX: 30 [13-56] and 31 [9-52], respectively, (p = 0.69) and P-MPW: 34 [17-58] and 36 [16-62], respectively (p = 0.96), and for aerobic results (mean ± standard error) P-VO2 (75.9 ± 1.3% and 75.0 ± 1.3%, respectively) (p = 0.83). When comparing extreme tertiles, a difference was found for P-MPW in the lower tertile only, with a slight advantage of AD over NAD- 9 [5-16] versus 4 [1-11] (p = 0.04). CONCLUSION: Although awareness of the pre-participation levels of aerobic and non-aerobic physical fitness components is useful for individualized exercise prescription, these variables do not seem to influence medium-term adherence to SEP.