Cardiorespiratory Fitness Groups Research Articles

Physical fitness is an independent predictor of chronic kidney disease development in apparently healthy individuals.

The cardiovascular and metabolic benefits of physical activity have been studied at length, however, data on the association between physical fitness and progression to kidney disease is lacking. We aimed to identify the association between cardiorespiratory fitness and development of chronic kidney disease (CKD) among the healthy population. We retrospectively investigated 11,579 healthy self-referred subjects who underwent annual medical screening. All subjects had an estimated glomerular filtration rate (eGFR) above 60 ml/min/1.73 m2, no known kidney disease, hematuria or proteinuria, and were free of diabetes or cardiovascular disease at baseline. All participants completed a maximal exercise test, and were categorized into low and high cardiorespiratory fitness groups based on age- and gender-specific quintiles. The primary end point was the development of significant CKD defined as eGFR below 45 ml/min/1.73 m2 during follow-up. Median follow-up was 7.6 years, and the participants' median age was 50 ± 8 years. Baseline creatinine and eGFR were 1.02 mg/dl and 81 ml/min/1.73 m2, respectively. During follow-up, 81 (0.6%) participants developed CKD, and the cumulative probability was significantly higher among the low fitness group (HR = 2.41, p = 0.001). The effect of physical fitness on the risk to develop CKD remained significant after adjusting for age, gender, baseline creatinine and other cardiovascular risk factors. Cardiorespiratory fitness is an independent risk factor inversely associated with development of CKD.

Polygenic Risk Score, Cardiorespiratory Fitness, and Cardiometabolic Risk Factors: WASEDA'S Health Study.

This study estimated an individual's genetic liability to cardiometabolic risk factors by polygenic risk score (PRS) construction and examined whether high cardiorespiratory fitness (CRF) modifies the association between PRS and cardiometabolic risk factors. This cross-sectional study enrolled 1296 Japanese adults aged ≥40 yr. The PRS for each cardiometabolic trait (blood lipids, glucose, hypertension, and obesity) was calculated using the LDpred2 and clumping and thresholding methods. Participants were divided into low-, intermediate-, and high-PRS groups according to PRS tertiles for each trait. CRF was quantified as peak oxygen uptake (V̇O 2peak ) per kilogram body weight. Participants were divided into low-, intermediate-, and high-CRF groups according to the tertile V̇O 2peak value. Linear regression analysis revealed a significant interaction between PRS for triglyceride (PRS TG ) and CRF groups on serum TG levels regardless of the PRS calculation method, and the association between PRS TG and TG levels was attenuated in the high-CRF group. Logistic regression analysis revealed a significant sub-additive interaction between LDpred2 PRS TG and CRF on the prevalence of high TG, indicating that high CRF attenuated the genetic predisposition to high TG. Furthermore, a significant sub-additive interaction between PRS for body mass index and CRF on obesity was detected regardless of the PRS calculation method. These significant interaction effects on high TG and obesity were diminished in the sensitivity analysis using V̇O 2peak per kilogram fat-free mass as the CRF index. Effects of PRSs for other cardiometabolic traits were not significantly attenuated in the high-CRF group regardless of PRS calculation methods. The findings of the present study suggest that individuals with high CRF overcome the genetic predisposition to high TG levels and obesity.

Measurement of Sedentary Behavior-The Outcomes of the Angle for Posture Estimation (APE) Method.

Hip-worn accelerometers are commonly used to assess habitual physical activity, but their accuracy in precisely measuring sedentary behavior (SB) is generally considered low. The angle for postural estimation (APE) method has shown promising accuracy in SB measurement. This method relies on the constant nature of Earth's gravity and the assumption that walking posture is typically upright. This study investigated how cardiorespiratory fitness (CRF) and body mass index (BMI) are related to APE output. A total of 3475 participants with adequate accelerometer wear time were categorized into three groups according to CRF or BMI. Participants in low CRF and high BMI groups spent more time in reclining and lying postures (APE ≥ 30°) and less time in sitting and standing postures (APE < 30°) than the other groups. Furthermore, the strongest partial Spearman correlation with CRF (r = 0.284) and BMI (r = -0.320) was observed for APE values typical for standing. The findings underscore the utility of the APE method in studying associations between SB and health outcomes. Importantly, this study emphasizes the necessity of reserving the term "sedentary behavior" for studies wherein the classification of SB is based on both intensity and posture.

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

Poor cardiorespiratory fitness may mediate vascular impairments at rest and following an acute bout of exercise in young healthy individuals. This study aimed to compare flow mediated dilation (FMD) and vascular augmentation index (AIx75) between young adults with low, moderate, and high levels of cardiorespiratory fitness before and after an acute bout of aerobic exercise. Forty-three participants (22 men; 21 women) between 18 and 29 years of age completed the study. Participants were classified into low, moderate, and high health-related cardiorespiratory fitness groups according to age- and sex-based relative maximal oxygen consumption (V˙O2 max) percentile rankings. FMD was performed using Doppler ultrasound and AIx75 was performed using pulse wave analysis at baseline and 60-min after a 30-min bout of treadmill running at 70% V˙O2 max. A significant interaction (p ​= ​0.047; ηp2 ​= ​0.142) was observed, with the moderate fitness group exhibiting a higher FMD post-exercise compared with baseline ([6.7% ​± ​3.1%] vs. [8.5% ​± ​2.8%], p ​= ​0.028; d ​= ​0.598). We found a significant main effect of group for AIx75 (p ​= ​0.023; ηp2 ​= ​0.168), with the high fitness group exhibiting lower AIx75 compared to low fitness group ([−10% ​± ​10%] vs. [2% ​± ​10%], respectively, p ​= ​0.019; g ​= ​1.07). This was eliminated after covarying for body fat percentage (p ​= ​0.489). Our findings suggest that resting FMD and AIx75 responses are not significantly influenced by cardiorespiratory fitness, but FMD recovery responses to exercise may be enhanced in individuals with moderate cardiorespiratory fitness levels.

Influence of Cardiorespiratory Fitness on Cardiac Autonomic Recovery Among Active-Duty Firefighters.

Abstract Cornell, DJ, Flees, RJ, Shemelya, CM, and Ebersole, KT. Influence of cardiorespiratory fitness on cardiac autonomic recovery among active-duty firefighters. J Strength Cond Res 38(1): 66–73, 2024—It has been suggested that an inability of the autonomic nervous system (ANS) to recover after strenuous events is a potential cause of sudden cardiac death among firefighters. The purpose of this study was to examine the influence of cardiorespiratory fitness (CRF) on the heart rate recovery (HRR) kinetics of firefighters. Thirty-seven male career active-duty firefighters completed both a submaximal step test and a maximal treadmill graded exercise test. A monoexponential curve was fit to postexercise submaximal and maximal HRR data of each subject. Subjects were placed into Low CRF (n = 13) and High CRF (n = 24) groups based on the standard peak aerobic capacity (V̇O2peak) criterion of &lt;42 ml·kg−1·minute−1 and ≥42 ml·kg−1·minute−1, respectively. After controlling for age and body mass index, CRF was significantly (p &lt; 0.05) correlated with the decay rate ( ) and asymptote ( ) after submaximal exercise (r sp = −0.556; r sp = −0.637, respectively), as well as the , , and amplitude ( ) after maximal exercise (r sp = −0.353; r sp = −0.416; r sp = 0.603, respectively). High CRF firefighters demonstrated a significantly faster after both submaximal (p = 0.003) and maximal exercise (p = 0.043), a lower after submaximal exercise (p = 0.002), and a higher after maximal exercise (p = 0.001), than Low CRF firefighters. Greater CRF was associated with enhanced HRR kinetics after submaximal and maximal exertion, suggesting that CRF may positively influence the ANS recovery of firefighters.

CORRELATION BETWEEN THE CARDIORESPIRATORY FITNESS LEVEL AND HABITUAL PHYSICAL ACTIVITY IN BRAZILIAN AIR FORCE RECRUITS

Cardiorespiratory fitness is the ability to maintain moderate or high-intensity efforts for long periods of time and is highly related to physical activity habits and fitness levels. Analyzing habitual physical activity in military personnel and its relationship with cardiorespiratory fitness is consequently fundamental. Thus, the objective of this study was to verify the correlation between the cardiorespiratory fitness level and habitual physical activity in Brazilian Air Force recruits. The sample consisted of 86 recruits in the final phase of the soldier training course. Data was collected using the 12-minute cardiorespiratory fitness test and the Baecke questionnaire validated for the Portuguese language to assess the practice of habitual physical activity. Descriptive statistics were used for sample characterization and exploratory analysis. The distribution of data normality was analyzed using the Shapiro-Wilk test, followed by Pearson’s correlation test and the Mann-Whitney U test to compare the groups with lower and higher cardiorespiratory fitness. The significance level of p ≤ 0.05 was adopted. According to the results, 63.9% of the sample had satisfactory cardiorespiratory fitness levels (good and excellent). No significant correlations were observed between cardiorespiratory fitness and habitual physical activity indices, except for the physical exercise/sports index (p= 0.05). It was found that only the Body Mass Index showed a difference (p= 0.017, Effect Size= 0.637) between the cardiorespiratory fitness groups. It is concluded that most military recruits have adequate cardiorespiratory fitness levels, but these are not influenced by the habitual practice of physical activity.&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/soc/0036/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

A bout of endurance and resistance exercise transiently decreases plasma levels of bile acids in young, sedentary adults.

Circulating bile acids (BA) are signaling molecules that control glucose and lipid metabolism. However, the effects of acute exercise on plasma levels of BA in humans remain poorly understood. Here, we evaluate the effects of a bout of maximal endurance exercise (EE) and resistance exercise (RE) on plasma levels of BA in young, sedentary adults. Concentration of eight plasma BA was measured by liquid chromatography-tandem mass spectrometry before and 3, 30, 60, and 120 min after each exercise bout. Cardiorespiratory fitness (CRF) was assessed in 14 young adults (21.8 ± 2.5 yo, 12 women); muscle strength was assessed in 17 young adults (22.4 ± 2.5 yo, 11 women). EE transiently decreased plasma levels of total, primary, and secondary BA at 3 and 30 min after exercise. RE exerted a prolonged reduction in plasma levels of secondary BA (p < 0.001) that lasted until 120 min. Primary BA levels of cholic acid (CA) and chenodeoxycholic acid (CDCA) were different across individuals with low/high CRF levels after EE (p ≤ 0.044); CA levels were different across individuals with low/high handgrip strength levels. High CRF individuals presented higher levels of CA and CDCA 120 min after exercise vs baseline (+77% and +65%) vs the low CRF group (-5% and -39%). High handgrip strength levels individuals presented higher levels of CA 120 min after exercise versus baseline (+63%) versus the low handgrip strength group (+6%). The study findings indicate that an individual's level of physical fitness can influence how circulating BA respond to both endurance and resistance exercise. Additionally, the study suggests that changes in plasma BA levels after exercising could be related to the control of glucose homeostasis in humans.

Relationship between Cardiorespiratory Fitness and Executive Function in Young Adults: Mediating Effects of Gray Matter Volume

We evaluated the association between cardiorespiratory fitness (CRF) and executive function (EF) in young adults and the mediating effects of GMV on this relationship. This study involved 217 college students. An incremental load exercise program was used to evaluate VO2max. EF was estimated by the Flanker task, the 2-back task, and the more-odd shifting task, while structural magnetic resonance and region-based morphometry (RBM) were used to analyze GMV. The high CRF group had a shorter updating reaction time (RT) (p ≤ 0.05). CRF was positively correlated with the right orbital part of the middle frontal gyrus (ORBmid.R) GMV (p ≤ 0.05). ORBmid.R GMV was negatively correlated with updating RT (p ≤ 0.05). Model 4 in SPSS was used to assess the mediating effects of ORBmid.R GMV between CRF and updating RT. ORBmid.R GMV was established to have a partially mediating role between CRF and updating RT, which accounted for 19.6% of the total effect value. These findings indicate that the negative correlation between CRF and EF was significant, and ORBmid.R GMV played a mediating role in the relationship between CRF and EF, providing new evidence toward comprehensively revealing that CRF promotes EF performance.

Cardiorespiratory Fitness Level Alters Blood Pressure Responses Induced By Histamine H1- And H2-receptor Blockade During Dynamic Exercise

INTRODUCTION: Epidemiological studies have reported that greater cardiorespiratory fitness (CRF) is associated with lower blood pressure (BP). Histamine receptor-mediated peripheral vasodilation contributes to post-exercise hypotension and lowing exercising BP responses. Previously, our laboratory found that overactive BP responses to exercise were induced by the inability of histamine receptors in individuals with prehypertension. However, it is still unknown that CRF can impact BP responses elicited by the inability of the receptors. PURPOSE: This study was to assess whether aerobic fitness is effective in lowering excessive BP responses induced by the blockade of histamine receptors METHODS: In twelve male and female subjects (6 high CRF and 6 low CRF), we examined the effects of histamine H1- and H2- receptor blockades on heart rate (HR), stroke volume (SV), cardiac output (CO), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and total peripheral resistance (TPR) at workloads corresponding to 40% and 60% workloads of VO2peak during cycling exercise. RESULTS: Our study indicated that compared to the high CRF group, changes in MAP from the baselines were higher in the low CRF group before the blockade at each workload (40%: D14±2 vs. 8±1 mmHg; 60%: D21±3 vs. 15±2 mmHg). The changes in MAP in response to the blockade during exercise were substantially lower in the high CRF group (40%: D18±2 vs. 11±1 mmHg; 60%: D29±3 vs. 19±2 mmHg). CONCLUSIONS: Our study suggests that an improvement in CRF likely reduces exaggerated BP responses elicited due to the inability of histamine receptors in pathological conditions such as prehypertension and hypertension.

How adherence to the updated physical activity guidelines should be assessed with accelerometer?

BackgroundThe aerobic part of the recently updated physical activity (PA) guidelines for adults recommends at least 150 min of moderate or at least 75 of vigorous-intensity PA or an equivalent combination of both. PA can be accumulated of any bout duration. On an absolute scale, moderate-intensity threshold is 3 metabolic equivalents (METs) and vigorous 6 METs. On a scale relative to individual’s personal capacity, moderate-intensity threshold is 40% and vigorous 60% of the oxygen uptake reserve. In this study, the adherence to the new guidelines was evaluated using both absolute and relative thresholds.MethodsTotally, 1645 adults aged 20–64 years, participated in this population-based study and their cardiorespiratory fitness (CRF) was estimated with 6-min walking test. The participants with estimated maximal oxygen uptake <7.9 MET were categorized as low CRF group and the others as adequate CRF group. The participants were instructed to wear a triaxial hip-worn accelerometer for 1 week and their adherence to PA guidelines was assessed from the accelerometer data.ResultsThe adequate CRF group had higher adherence to PA guidelines with the absolute thresholds, but the use of relative thresholds inverted the results. The adherence varied from 20% to 99% in the total sample depending on the analysis parameters of accelerometer data.ConclusionsThe absolute thresholds provide a more appropriate basis to assess the adherence to PA guidelines in population-based samples and interventions. The use of individually determined relative thresholds may be more useful for individual exercise prescriptions in PA counseling.

P-103 Physical fitness is positively associated with sperm quality in healthy young men

Abstract Study question Do sperm quality parameters differ between “high” and “low” cardiorespiratory fitness (CRF) and muscular strength levels in healthy young men? Summary answer Self-reported CRF was positively associated with sperm count and concentration, while muscular strength (objectively measured and self-reported) did not correlate with seminal parameters. What is known already Physical activity (i.e., any body movement that results in energy expenditure) levels are positively associated with sperm quality parameters in healthy men. In this context, physical fitness, which is modifiable by physical activity, is a powerful marker of health that integrates several body functions such as hematocirculatory, skeletomuscular, phsychoneurological and endocrine-metabolic. In particular, the main components of physical fitness (i.e., CRF and muscular strength) have been negatively related to the risk of all-cause mortality in any age population. However, the association of CRF and muscular strength with sperm quality parameters in healthy young men is unknown. Study design, size, duration This cross-sectional study included 253 healthy men (age= 22.63 ± 5.04 years, BMI= 22.84 ± 1.33). Semen samples and physical fitness assessment were performed between March 2019 and July 2021 at the sperm biobank (Ceifer Biobank – NextClinics). The study was approved by the Ethics Committee of Investigación Biomédica de Andalucía. Participants/materials, setting, methods CRF was self-reported using the The International FItness Scale (IFIS). Muscular strength was objectively assessed using a handgrip dynamometer and self-reported with IFIS. Semen samples were analysed by clinical technicians to determine sperm count, sperm concentration and progressive motility. Analysis of covariance (ANCOVA) was performed to obtain adjusted mean differences on sperm quality parameters between high and low CRF and muscular strength groups after including age and body mass index as confounders. Main results and the role of chance Men with higher CRF presented increased sperm count and concentration compared to men with lower CRF values (adjusted mean differences 43.581 x 106 [2.630, 84.532; 95% confidence interval] and 10.131 x 106/ml [0.799, 19.463; 95% confidence interval]; both p &amp;lt; 0.05). Muscular strength (objectively measured and self-reported) was not associated with any semen quality parameter (all p &amp;gt; 0.05) when including age and body mass index as covariates. Limitations, reasons for caution This study reported a positive association between self-reported CRF using IFIS questionnaire and sperm count and concentration in healthy young men. Although the validity of the self-reported CRF using IFIS has been widely proved in healthy young adults, objectively measured CRF is needed to further confirm our findings. Wider implications of the findings Infertility has increased in the last decades. Therefore, more research is needed to identify health indicators that affect sperm quality. Our results suggest that self-reported CRF could contribute to the identification of young men with poor seminal quality and a higher risk of infertility later in life. Trial registration number NA

A Nonexercise Estimate of Cardiorespiratory Fitness Using a Symptom Questionnaire and Clinical Variables.

Cardiorespiratory fitness (CRF) has recently been recognized as a risk factor for mortality, but it is not routinely measured in clinical settings. The purpose of this study was to assess a nonexercise method to estimate CRF (eCRF) and its association with mortality in a clinically referred population. A symptom tool, termed the Veterans Specific Activity Questionnaire (VSAQ), and nonexercise clinical variables were obtained from 1545 clinically referred subjects (60 ± 13 yr), and followed for a mean of 5.6 ± 4.2 yr. The VSAQ along with nonexercise clinical and historical variables was used to develop a multivariate model to predict achieved CRF from maximal exercise testing. Proportional hazards analysis was used to assess the association between measured and eCRF and all-cause mortality. The eCRF model was significantly associated with achieved CRF (multiple R = 0.67, P < .001). Mean achieved CRF from maximal treadmill testing and eCRF were similar (8.6 ± 5.0 metabolic equivalents [METs] vs 8.7 ± 4.7 METs respectively, P = .27). Achieved CRF and eCRF performed similarly for predicting mortality. After full adjustment, each 1 MET higher increment in achieved CRF and eCRF was associated with 19% and 26% reductions in mortality risk, respectively. Compared with the lowest fit group (<5 METs), the highest CRF groups (>11 METs) had 88% and 87% lower risks for mortality for achieved CRF and eCRF, respectively. A multivariable nonexercise model featuring a symptom questionnaire combined with clinical variables that are readily available during a typical clinical encounter had a reasonably strong association with achieved CRF and exhibited prognostic characteristics that were similar to achieved CRF.

The combination of cardiorespiratory fitness and muscular fitness, and prevalence of diabetes mellitus in middle-aged and older men: WASEDA\u2019S Health Study

BackgroundAlthough the negative relationship between cardiorespiratory fitness (CRF) or muscular fitness and diabetes mellitus were respectively observed in many previous studies, there is still a lack of studies that include CRF and muscular fitness simultaneously. Therefore, this study aimed to investigate the relationship between the combination of CRF and muscular fitness and diabetes through a cross-sectional study. MethodsThis study was part of WASEDA'S Health Study, a cohort study launched in 2014. We used a part of the baseline data collected for this study. Maximal exercise test using a cycle ergometer and leg extension power (LEP) test were respectively used to evaluate CRF and muscular fitness. Since LEP is affected by body weight, relative LEP (rLEP) which is LEP per body weight, was used as an index of muscular fitness. 796 men (56.5 ± 10.4 years old) who completed a medical examination and fitness tests, were divided into two groups based on CRF and rLEP, respectively. The prevalence of diabetes was collected based on a self-reported questionnaire or blood test. Odds ratios and 95% confidence intervals (CIs) for the prevalence of diabetes were obtained using logistic regression models while adjusting for age, body mass index, exercise habits, family history of diabetes, smoking habits, and drinking habits.Results55 (7%) participants had diabetes. Compared to participants with lower CRF or rLEP, the odds ratio (95% CIs) of diabetes in those with higher CRF or rLEP was 0.46 (0.21–0.98) or 0.34 (0.16–0.74), respectively. Furthermore, using the lower CRF and lower rLEP group as the reference, the odds ratio (95% CIs) for the lower CRF and higher rLEP group was 0.32 (0.12–0.88), and higher CRF and higher rLEP group was 0.21 (0.07–0.63), after adjusting for potential confounding factors.ConclusionsCRF and rLEP have independent and joint inverse associations with diabetes prevalence. In addition, participants with high CRF and high rLEP had a lower prevalence of diabetes compared to those with only high CRF or only high rLEP.

Changes in Hippocampus and Amygdala Volume with Hypoxic Stress Related to Cardiorespiratory Fitness under a High-Altitude Environment.

The morphology of the hippocampus and amygdala can be significantly affected by a long-term hypoxia-induced inflammatory response. Cardiorespiratory fitness (CRF) has a significant effect on the neuroplasticity of the hippocampus and amygdala by countering inflammation. However, the role of CRF is still largely unclear at high altitudes. Here, we investigated brain limbic volumes in participants who had experienced long-term hypoxia exposure in Tibet (3680 m), utilizing high-resolution structural images to allow the segmentation of the hippocampus and amygdala into their constituent substructures. We recruited a total of 48 participants (48 males; aged = 20.92 ± 1.03 years) to undergo a structural 3T MRI, and the levels of maximal oxygen uptake (VO2max) were measured using a cardiorespiratory function test. Inflammatory biomarkers were also collected. The participants were divided into two groups according to the levels of median VO2max, and the analysis showed that the morphological indexes of subfields of the hippocampus and amygdala of the lower CRF group were decreased when compared with the higher CRF group. Furthermore, the multiple linear regression analysis showed that there was a higher association with inflammatory factors in the lower CRF group than that in the higher CRF group. This study suggested a significant association of CRF with hippocampus and amygdala volume, which may be related to hypoxic stress in high-altitude environments. A better CRF reduced physiological stress and a decrease in the inflammatory response was observed, which may be related to the increased oxygen transport capacity of the body.

High fitness levels attenuate the increased risk of heart failure due to low socioeconomic status: A cohort study

High fitness levels attenuate the increased risk of heart failure due to low socioeconomic status: A cohort study

Association between Cardiorespiratory Fitness, Muscle Strength, and Non-Alcoholic Fatty Liver Disease in Middle-Aged Men

Background: Nonalcoholic fatty liver disease (NAFLD) occurs when more than 5% of fat accumulates in the liver parenchyma without excess alcohol consumption. The objective of this study is to investigated the association between cardiorespiratory fitness (CRF), muscle strength (MS), and NAFLD. Methods: The subjects of this study were 1325 males aged 40–50 who had visited the National Fitness Center located in the Republic of Korea from 2017 to 2019. Abdominal ultrasonography testing was used for NAFLD diagnosis. For CRF, an MS test was used to measure maximal oxygen intake and grip strength. CRF and MS were classified into 3 quartiles (high, middle, low-level). In addition, both the CRF level and MS level were classified into 9 quadrants. Results: With confounding factors (age, body mass index, exercise, smoking) controlled, there was no relative risk of NAFLD between middle and high levels of CRF (95% CI, 0.92–2.17). However, the relative risk of NAFLD in the case of low-level CRF was 1.63-fold (95% CI, 1.03–2.60, p &lt; 0.05) higher than that in the case of high-level CRF. Meanwhile, there was no significant difference between middle-level MS (95% CI, 0.68–1.65) and high-level MS (95% CI, 0.84–1.99) in terms of NAFLD relative risk. The NAFLD relative risk in the case of low-level CRF/MS was 2.27-fold (95% CI, 0.94–1.99, p &lt; 0.05) higher than that of high-level CRF/MS. Conclusions: The low CRF and MS group had a higher risk of NAFLD compared with the high CRF and MS group. Maintenance of high CRF and MS may be beneficial in preventing NAFLD.

Sex Differences in the Prevalence of Metabolic Syndrome Based on Leg Strength, Cardiorespiratory Fitness, and Skeletal Muscle Mass in Elderly

Background: Metabolic syndrome (MetS) is characterized by abdominal obesity, high blood glucose, and dyslipidemia. Low fitness, muscle mass, and strength increase the risk of MetS. The characteristics of these variables are highly interrelated. This cross-sectional study aimed to analyze the prevalence of MetS by combining leg strength (LSTR), cardiorespiratory fitness (CRF), and appendicular skeletal muscle mass (ASM) in elderly men and women. Methods: Participants included 1420 persons aged 65–79 years (men: 753, women: 667). An isokinetic dynamometer was used to measure LSTR; CRF was evaluated by measuring maximum oxygen uptake; and ASM was assessed using bio-impedance analysis. The measured CRF, LSTR, and ASM were converted to relative values by dividing by body weight and grouped into ‘high’ and ‘low’ based on the median value. The diagnosis of MetS was based on five criteria: waist circumference, blood pressure, high-density lipoprotein cholesterol, triglycerides, and fasting glucose. MetS was diagnosed when the participant fulfilled 3 or more of the criteria, and odds ratios (ORs) were analyzed using logistic regression. Results: MetS was diagnosed in 32.1% and 30.3% of men and women, respectively. The relative LSTR and ASM values were significantly higher in the non-MetS group compared to those of the MetS group in both sexes. The OR for MetS in men was 3.6-fold higher in the low LSTR group, 3.5-fold higher in the low CRF group, and 2.3-fold higher in the low ASM group than in the high groups. In women, the OR for MetS increased 1.3-fold in the group with low LSTR and 3.7-fold in the group with low CRF. The OR for MetS exhibited a 3.5-fold increase in men and a 2.4-fold increase in women for combined low LSTR and low ASM compared to those of the combined high LSTR and high ASM group. Despite high ASM, the OR for MetS was a 3.5-fold higher in men and a 3.9-fold in women for low LSTR and low CRF group. Conclusions: The prevalence of MetS increased in elderly with relatively decreased LSTR, ASM and decreased CRF. Furthermore, the prevalence of MetS is increased when both LSTR and ASM are low despite high CRF. In addition, even if ASM was low, the risk of metabolic syndrome did not increase when both CRF and LSTR were high. In conclusion, when two or more of the three variables CRF, LSTR, and ASM were low, the prevalence of MetS increased.

Cardiorespiratory fitness and lifestyle on severe COVID-19 risk in 279,455 adults: a case control study

BackgroundThe impact of cardiorespiratory fitness (CRF) and other lifestyle-related factors on severe COVID-19 risk is understudied. The present study aims to investigate lifestyle-related and socioeconomic factors as possible predictors of COVID-19, with special focus on CRF, and to further study whether these factors may attenuate obesity- and hypertension-related risks, as well as mediate associations between socioeconomic factors and severe COVID-19 risk.MethodsOut of initially 407,131 participants who participated in nationwide occupational health service screening between 1992 and 2020, n = 857 cases (70% men, mean age 49.9 years) of severe COVID-19 were identified. CRF was estimated using a sub-maximum cycle test, and other lifestyle variables were self-reported. Analyses were performed including both unmatched, n = 278,598, and sex-and age-matched, n = 3426, controls. Severe COVID-19 included hospitalization, intensive care or death due to COVID-19.ResultsPatients with more severe COVID-19 had significantly lower CRF, higher BMI, a greater presence of comorbidities and were more often daily smokers. In matched analyses, there was a graded decrease in odds for severe COVID-19 with each ml in CRF (OR = 0.98, 95% CI 0.970 to 0.998), and a two-fold increase in odds between the lowest and highest (< 32 vs. ≥ 46 ml·min−1·kg−1) CRF group. Higher BMI (per unit increase, OR = 1.09, 1.06 to 1.12), larger waist circumference (per cm, OR = 1.04, 1.02 to 1.06), daily smoking (OR = 0.60, 0.41 to 0.89) and high overall stress (OR = 1.36, 1.001 to 1.84) also remained significantly associated with severe COVID-19 risk. Obesity- and blood pressure-related risks were attenuated by adjustment for CRF and lifestyle variables. Mediation through CRF, BMI and smoking accounted for 9% to 54% of the associations between low education, low income and blue collar/low skilled occupations and severe COVID-19 risk. The results were consistent using either matched or unmatched controls.ConclusionsBoth lifestyle-related and socioeconomic factors were associated with risk of severe COVID-19. However, higher CRF attenuated the risk associated with obesity and high blood pressure, and mediated the risk associated with various socioeconomic factors. This emphasises the importance of interventions to maintain or increase CRF in the general population to strengthen the resilience to severe COVID-19, especially in high-risk individuals.

Cardiorespiratory fitness and electroanatomical remodelling in patients with atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Atrial fibrillation (AF) is the most common clinically-relevant arrhythmia. Its initiation and maintenance is linked to the presence cardiovascular risk factors such as hypertension and obesity. Higher cardiorespiratory fitness (CRF) has been associated with a better prognosis. However, specific electroanatomical features associated with baseline CRF have not been described. Purpose Compare electroanatomical substrate across exercise capacity levels in patients with AF Methods Patients referred for de novo AF radiofrequency ablation at the Centre for Heart Rhythm Disorders from August 2017 until June 2020 were screened for inclusion and CRF was evaluated in metabolic equivalents (METs) by a symptom-limited maximal treadmill exercise test using the standard Bruce protocol prior to ablation. Predicted CRF was calculated based on established equations and patients were categorized according to the percentage of predicted CRF achieved; low (&amp;lt;85%), adequate (85-100%) and high (&amp;gt;100%). Total mean and regional peak-to-peak bipolar voltages, percent of low voltage areas (% LVA), conduction velocity (CV) and percent of complex fractionated electrograms (% CFE) in sinus rhythm were compared across groups. Results There were no between-group differences in baseline characteristics, medication use or echocardiographic features. Total mean voltage was significantly lower in the low CRF group compared to both adequate and high CRF. Compared to the high CRF group, roof (3.25 ± 1.2 mV vs 1.9 ± 1.3 mV, p &amp;lt; 0.05), posterior (3.8 ± 1.8 mV vs 1.7 ± 0.9 mV, p &amp;lt; 0.001) and inferior mean voltages (3.4 ± 2 mV vs 1.6 ± 0.7 mV, p &amp;lt; 0.05) were significantly lower in the low CRF group (figure 1A). Furthermore, compared with the adequate CRF group, mean voltages were significantly lower in the posterior (3.7 ± 1.5 mV vs 1.7 ± 0.9 mV, p &amp;lt; 0.001), inferior (3.4 ± 1 mV vs 1.6 ± 0.7 mV, p &amp;lt; 0.001) and lateral (4.2 ± 2.2 mV vs 2.1 ± 1.4 mV, p &amp;lt; 0.05) walls of the low CRF group. Anterior and septal mean voltages were not significantly different across CRF groups (P for trend = 0.07, 0.3 and 0.15, respectively). Conduction velocities were not significantly different across groups. The inferior %LVA was significantly higher in the low CRF (5.6 ± 6%) compared to adequate CRF group (23 ± 18%) (p &amp;lt; 0.05) (figure 1B). Total and regional % CFE was higher in the low CRF compared to adequate and high CRF. Conclusion Participants in the lower baseline CRF category showed significant reductions in regional voltages along with higher fractionation with preserved conduction velocities. Research on the effect of physical activity and CRF on left atrial arrhythmogenic substrate is required. Abstract Figure. Global and regional mV and % LVA by CRF

Greater cardiorespiratory fitness reduces incidence of atrial fibrillation: a meta-analysis

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Atrial Fibrillation (AF) is the most common sustained cardiac arrhythmia affecting 1-2% of the global population, with the prevalence of AF increasing dramatically over the past two decades. Although low levels of cardiorespiratory fitness (CRF) and physical activity are predictive of cardiovascular disease onset and mortality, only recently has this emerged as a potential risk factor for AF. Purpose The aim of this meta-analysis was therefore to quantify the relationship between CRF, measured by a symptom limited exercise stress test, and incident AF. We hypothesised that there would be an inverse relationship between CRF and the incidence of AF. Methods The systematic literature review was conducted using PUBMED, MEDLINE and EMBASE databases, with seven studies meeting the inclusion criteria. A random-effects meta-analysis was then used to compare the multivariate risk estimates of the lowest CRF group from each cohort with the group of the highest CRF. Results Data from 206,925 individuals (55.8% males) was used for analysis with a mean age of 55 ± 2.5 years and a mean follow-up period of 10.3 ± 5 years. The total number of AF events across the studies was 19,913. The overall pooled risk of AF in the high-CRF group versus the low-CRF group showed a significant lower risk of incident AF in those with high-CRF (OR: 0.52, 95% CI, 0.44-0.605, p &amp;lt; 0.001). There was evidence of statistical heterogeneity between the studies (I2 = 81%, p &amp;lt; 0.001). AF incidence rates demonstrated an overall decline in rates across the CRF quartiles from low to high. The mean incidence rate for low-CRF was 21 ± 13.4 compared to 6.9 ± 0.7 per 1000 person-years for the high CRF group (p = 0.03). Conclusion There is an inverse association between a lower CRF and an increased risk of AF, with a higher level of CRF protective against AF. This study highlights that low-CRF may be an additional risk factor for AF along with already other established lifestyle-based risk factors such as obesity and hypertension. Exercise interventions should be promoted as a primary prevention strategy in those at risk of developing AF with known risk factors. Future studies are warranted to identify the mechanism(s) through which improved CRF confers a reduction in AF incidence. Abstract Figure. AF risk between high and low-CRF