Effects of age on ventilatory threshold and peak oxygen uptake normalised for regional skeletal muscle mass in Japanese men and women aged 20–80 years

Reference values for estimated VO2max by two submaximal cycle tests: the Åstrand-test and the Ekblom-Bak test

AIMS

Submaximal tests estimating VO2max have inherent biases; hence, using VO2max estimations from the same test is essential for reducing this bias. This study aimed to establish sex- and age-specific reference values for estimated VO2max using the Åstrand-test (Å-test) and the Ekblom-Bak test (EB-test). We also assessed the effects of age, exercise level, and BMI on VO2max estimations.

METHODS

We included men and women (20-69 years) from the Swedish working population participating in Health Profile Assessments between 2010 and 2020. Excluding those on heart rate-affecting medicines and smokers, n = 263,374 for the Å-test and n = 95,043 for the EB-test were included. VO2max reference values were based on percentiles 10, 25, 40, 60, 75, and 90 for both sexes across 5-year age groups.

RESULTS

Estimated absolute and relative VO2max were for men 3.11 L/min and 36.9 mL/min/kg using the Å-test, and 3.58 L/min and 42.4 mL/min/kg using the EB-test. For women, estimated absolute and relative VO2max were 2.48 L/min and 36.6 mL/min/kg using the Å-test, and 2.41 L/min and 35.5 mL/min/kg using the EB-test. Higher age (negative), higher exercise level (positive), and higher BMI (negative) were associated with estimated VO2max using both tests. However, explained variance by exercise on estimated VO2max was low, 10% for the Å-test and 8% for the EB-test, and moderate for BMI, 23% and 29%.

CONCLUSION

We present reference values for estimated VO2max from two submaximal cycle tests. Age, exercise, and BMI influenced estimated VO2max. These references can be valuable in clinical evaluations using the same submaximal tests.

Age-related decline in peak oxygen uptake: Cross-sectional vs. longitudinal findings. A review

Cardiorespiratory fitness is established as an important prognostic factor for cardiovascular and general health. In clinical settings cardiorespiratory fitness is often measured by cardiopulmonary exercise testing determining the gold-standard peak oxygen uptake (VO_2peak). Due to the considerable impact of age and sex on VO_2peak, results from cardiopulmonary exercise testing are typically assessed in the context of age- and sex-specific reference values, and multiple studies have been conducted establishing reference materials by age and sex using cross-sectional designs. However, crossectional and longitudinal studies have shown somewhat conflicting results regarding age-related declines of VO_2peak, with larger declines reported in longitudinal studies. In this brief review, we compare findings from crossectional and longitudinal studies on age-related trajectories in VO_2peak to highlight differences in these estimates which should be acknowledged when clinicians interpret VO_2peak measurements repeated over time.

Effects of different exercise intensities on prefrontal activity during a dual task

The effects of physical exercise on cognitive tasks have been investigated. However, it is unclear how different exercise intensities affect the neural activity. In this study, we investigated the neural activity in the prefrontal cortex (PFC) by varying the exercise intensity while participants performed a dual task (DT). Twenty healthy young adults performed serial subtraction while driving a cycle ergometer. Exercise intensity was set to one of three levels: low, moderate, or high intensity. We did not find any significant change in PFC activity during DT under either the control (no exercise) or low-intensity conditions. In contrast, we observed a significant increase in PFC activity during DT under moderate- and high-intensity conditions. In addition, we observed complex hemodynamics after DT. PFC activity decreased from baseline after DT under the control condition, while it increased under the low-intensity condition. PFC activity remained higher than the baseline level after DT under the moderate-intensity condition but returned to baseline under the high-intensity condition. The results suggest that moderate-intensity exercise with a cognitive load effectively increases PFC activity, and low-intensity exercise may increase PFC activity when combined with a cognitive load.

Differences between Elite Male and Female Badminton Athletes Regarding Heart Rate Variability, Arterial Stiffness, and Aerobic Capacity

Cardiovascular health and aerobic capacity play crucial roles in determining the performance of athletes in the highly competitive sport of badminton. Few studies have directly compared heart rate variability (HRV), arterial stiffness, and aerobic capacity between male and female athletes, especially among badminton athletes. This study investigated sex differences in HRV, arterial stiffness, and aerobic capacity in badminton athletes. Elite badminton athletes were recruited and divided into male (n = 20, 21.0 ± 1.8 years old) and female (n = 16, 21.2 ± 2.3 years old) groups. Both groups performed an incremental treadmill running test for the evaluation of maximal oxygen consumption (V.O2max), anaerobic threshold, and time to exhaustion. They started exercising at a treadmill speed of 2.7 km/h and an inclination of 10% gradient for 3 min, and the speed and inclination were gradually increased every 3 min until they were exhausted or fatigued volitionally. HRV was examined using the Polar heart rate monitor over a period of 5 min at rest in the supine position. Subsequently, the index of arterial stiffness was examined under the same condition. Our results revealed significant differences between the male and female athletes in V.O2max (men: 60.38 ± 8.98 mL/kg/min, women: 48.13 ± 7.72 mL/kg/min, p < 0.05), anaerobic threshold (men: 41.50 ± 7.26 mL/kg/min, women: 32.51 ± 6.19 mL/kg/min, p < 0.05), time to exhaustion (men: 902.15 ± 120.15 s, women: 780.56 ± 67.63 s, p < 0.05), systolic blood pressure (men: 125.27 ± 7.76 mmHg, women: 107.16 ± 11.09 mmHg, p < 0.05), and arterial stiffness index (men: 63.56 ± 12.55, women: 53.83 ± 8.03, p < 0.05). However, no significant differences in HRV measures were observed between the two groups. These findings suggested that the male badminton athletes demonstrated significantly higher aerobic capacity than did the female athletes, but there were no significant differences in HRV measures. The female athletes exhibited superior arterial function, compared with their male counterparts.

The association between preoperative body composition and aerobic fitness in patients scheduled for colorectal surgery

AIM

Although cardiopulmonary exercise testing (CPET) is considered the gold standard, a preoperative abdominal CT scan might also provide information concerning preoperative aerobic fitness for risk assessment. This study aimed to investigate the association between preoperative CT-scan-derived body composition variables and preoperative CPET variables of aerobic fitness in colorectal surgery.

METHOD

In this retrospective cohort study, CT images at level L3 were analysed for skeletal muscle mass, skeletal muscle radiation attenuation, visceral adipose tissue (VAT) mass and subcutaneous adipose tissue mass. Regression analyses were performed to investigate the relation between CT-scan-derived body composition variables, CPET-derived aerobic fitness and other preoperative patient-related variables. Logistic regression analysis was performed to predict a preoperative anaerobic threshold (AT) ≤ 11.1 ml/kg/min as cut-off for having a high risk for postoperative complications.

RESULTS

Data from 78 patients (45 men; mean [SD] age 74.5 [6.4 years]) were analysed. A correlation coefficient of 0.55 was observed between absolute AT and skeletal muscle mass index. Absolute AT (R² of 51.1%) was lower in patients with a lower skeletal muscle mass index, together with higher age, lower body mass and higher American Society of Anesthesiologists (ASA) score. Higher ASA score (odds ratio 5.64; P = 0.033) and higher VAT mass (odds ratio 1.02; P = 0.036) were associated with an increased risk of an AT ≤ 11.1 ml/kg/min.

CONCLUSION

Body composition variables from the preoperative CT scan were moderately associated with preoperative CPET-derived aerobic fitness. Higher ASA score and higher VAT mass were associated with an increased risk of an AT ≤ 11.1 ml/kg/min.

Comparison Between the Effects of Continuous and Intermittent Light-Intensity Aerobic Dance Exercise on Mood and Executive Functions in Older Adults

There is a growing body of evidence suggesting that one bout of moderate-intensity exercise enhances executive functions in older adults. However, in terms of safety, feasibility, and continuity, older individuals prefer light, easy, and fun exercises to moderate and stressful exercises for improving executive functions. Therefore, light-intensity aerobic dance exercise (LADE) could be suitable if it produces potential benefits related to executive functions. As for continuous vs. intermittent exercise, intermittent exercise has received a lot of attention, as it results in greater effects on mood and executive functions than continuous exercise; however, its effects in older adults remain uncertain. Thus, in this study, we aimed to examine the acute effects of intermittent LADE (I-LADE) in comparison with those of continuous LADE (C-LADE) on mood and executive functions. Fifteen healthy older adults participated in 10-min I-LADE and C-LADE conditions on separate days. Perceived enjoyment following exercise was assessed using the Physical Activity Enjoyment Scale (PACES). The pleasantness of the mood during exercise and pleasure and arousal levels after exercise were assessed using the Feeling Scale and Two-Dimensional Mood Scale, respectively. Executive function was assessed using the Stroop task before and after exercise. As a result, pleasantness of the mood during exercise and exercise enjoyment levels were greater in I-LADE than in C-LADE. Arousal and pleasure levels and Stroop task performance increased after both LADEs and did not differ between the two exercise conditions. These findings suggest that although enhancement of mood and executive functions after exercise did not differ between C-LADE and I-LADE, I-LADE could be more enjoyable and fun than C-LADE. This study will help in the development of exercise conditions that can enable the elderly to enhance their executive functions in a fun way.

Association between pulmonary oxygen uptake on-kinetics and acute cardiovascular responses to resistance exercise in patients with coronary artery disease: a preliminary study

[Purpose] This study aimed to examine whether pulmonary oxygen uptake on-kinetics at the onset of moderate-intensity exercise can predict acute cardiovascular responses to resistance exercise. [Participants and Methods] The association between pulmonary oxygen uptake on-kinetics and acute cardiovascular responses to a single resistance exercise session was investigated in seven patients with low-risk coronary artery disease who underwent revascularization through percutaneous coronary intervention. The participants performed a cardiopulmonary exercise test on a cycle ergometer and a single resistance exercise session at 30% of maximum voluntary contraction on a bilateral leg-extension machine 1 week after surgery. We measured the ventilatory anaerobic threshold and pulmonary oxygen uptake on-kinetics during the cardiopulmonary exercise test; left ventricular ejection fraction at rest; and heart rate, systolic blood pressure, and rate pressure product during the single resistance exercise session. [Results] Pulmonary oxygen uptake on-kinetics showed a positive association with the amount of increase in systolic blood pressure and rate pressure product during the single resistance exercise session, but had no association with the amount of increase in heart rate. Ventilatory anaerobic threshold and left ventricular ejection fraction were not associated with these parameters. [Conclusion] These data suggested that pulmonary oxygen uptake on-kinetics can be a useful evaluation index for predicting acute systolic blood pressure and rate pressure product responses to low-intensity resistance exercise 1 week after percutaneous coronary intervention in patients with low-risk coronary artery disease.

Ultrasound assessment of muscle mass in the diagnosis of sarcopenia in cardiovascular patients

Aim. To study the advantages of ultrasound versus anthropometric assessment of muscle mass for early diagnosis of sarcopenia in patients >45 years of age.

Material and methods. The study included 79 patients aged 4589 years with coronary artery disease (CAD), hypertension, type 2 diabetes, heart failure, class 1-3 obesity. Diagnosis of hypertension was carried out according to the European (2018) and Russian (2019) guidelines; CAD — according to Russian Society of Cardiology (2020) guidelines. Sarcopenia was diagnosed according to 2010 European Working Group on Sarcopenia in Older People (EWGSOP) criteria and 2018 EWGSOP2 guidelines. Muscle mass (MM) was determined by two methods: 1 — by measuring the rectus abdominis muscle (RAM) thickness using the ultrasound; 2 — by measuring the arm and lower leg circumference. Muscle strength was determined by wrist dynamometer. Muscle function was assessed using the 4-m gait speed test.

Results. The study showed that in patients aged >45 years admitted to the emergency cardiology department, the body mass index exceeded 25 kg/m2 in 88,6% of cases. The incidence of sarcopenia of varying severity was 55,7% (n=44). The differences in RAM thickness, arm and lower leg circumference between the groups of patients with/without sarcopenia were significant (p<0,001), but were less than the threshold only for RAM thickness. RAM thickness levels progressively decreased with increasing severity of sarcopenia and significantly differed at all stages compared to patients without sarcopenia (p<0,001), regardless of body mass index. A decrease in lower leg circumference below the threshold values determining a MM decrease was observed only in severe sarcopenia, and arm circumference — in both men and women only in severe sarcopenia. There were no significant differences for arm and lower leg circumference depending on sarcopenia stages in overweight and obese patients.

Conclusion. MM assessment by measuring RAM thickness with ultrasound in comparison with the anthropometric method makes it possible to diagnose sarcopenia in patients >45 years of age with cardiovascular diseases and obesity at earlier stages and to promptly recommend preventive measures.

Better Executive Function Is Associated With Faster On-Transition Aerobic Metabolism Among Older Adults

The present study aimed to examine relationships between executive function (EF) and variables of aerobic fitness. Participants were 32 healthy older adults (M age = 65.1, SD = 6.6 years). We measured the first ventilatory threshold (VeT₁) and the kinetics of oxygen uptake (V˙O₂), heart rate (HR), and muscle deoxygenation [HHb] during treadmill walking of either constant, moderate intensity, or increasing intensity. We assessed EF with a computerized Stroop test and Stroop measures of correct answers, reaction time, and percent interference. We found the Stroop interference score to be negatively associated with the VeT₁ (r = -0.387, p = 0.031) and positively associated with the on-transition aerobic metabolism time constant (τ) of HR (r = 0.519, p = 0.003), V˙O₂ (r = 0.454; p = 0.010), and [HHb] (r = 0.644, p = 0.001). Correct responses were negatively related with τHR (r = -0.372, p = 0.039) and τV˙O₂ (r = -0.500, p = 0.004). The Stroop average reaction time, congruent reaction time and incongruent reaction time were positively related to τ[HHb] (r = 0.507, p = 0.010; r = 0.437, p = 0.029; r = 0.558, p = 0.004, respectively). Better EF was associated with faster on-transition aerobic metabolism and higher aerobic fitness among older adults.

The relationships among the skeletal muscle mass index, cardiorespiratory fitness and the prevalence of coronary artery disease in the elderly population

OBJECTIVE

Few studies have investigated the association between cardiorespiratory fitness (CRF) impairment and coronary artery disease (CAD) and the mediating mechanism. Therefore, we investigated the impact of skeletal muscle mass (SMM) on the relationship between CRF and coronary artery disease (CAD) in elderly people.

METHODS

In this cross-sectional study, 109 elderly patients with coronary artery stenosis ≥50% were included in the CAD group, and 148 patients with coronary artery stenosis <50% were included as controls. Mediation analyses were performed to determine the role of the skeletal muscle index (SMI) in the relationship between CRF and the prevalence of CAD. A receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive value of CRF markers and the SMI.

RESULTS

The oxygen pulse, VO₂ max, and MET max were significantly associated with the SMI. In the multiple logistic regression analyses, the oxygen pulse and SMI were both independently correlated with the prevalence of CAD. The mediation analyses showed that the SMI affects the relationship between CRF markers (oxygen pulse, VO₂ max, and MET max) and the prevalence of CAD. The receiver operating characteristic (ROC) curve analysis showed that when CRF and the SMI are considered together, the predictive power for CAD is stronger than that of the CRF alone.

CONCLUSION

Enhancing CRF can facilitate improvement in SMM and decrease the prevalence of CAD in the elderly population. The addition of the SMI to CRF markers may increase the predictive value of CAD.

The effect of age and training status on oxygen uptake kinetics in women

We examined the effect of age and training status on the oxygen uptake (V˙ O₂) kinetics of untrained and recreationally trained women. Young (20-35yr), middle-age (40-55yr) and older (58-71yr) recreationally trained (YTR, n = 10; MTR, n = 12; OTR, n = 9) and untrained (YUT, n = 12; MUT, n = 10; OUT, n = 9) women participated in this crossectional study. Breath-by-breath V˙ O₂ and near-infrared-spectroscopy-derived (NIRS) muscle deoxygenation [HHb] were monitored continuously during increasing and constant walking exercises. On-transition V˙ O₂ and [HHb] responses to moderate intensity walking were modeled as mono-exponential. The data were normalized for each subject (0%-100 %), and [HHb]/ V˙ O₂ ratio was calculated as the average [HHb]/ V˙ O₂ during the 20- to 120-s period after the onset of moderate intensity walking exercise. The time constant of V˙ O₂ (τ V˙ O₂) was longer in OUT(23.8 ± 2.4), MUT(25.4 ± 5.1), YUT(23.1 ± 3.4) than in YTR(16.2 ± 2.0), MTR(16.7 ± 3.9), OTR(16.3 ± 2.8) women (p < 0.05). The [HHb]/ V˙ O₂ ratio in OUT (1.31 ± 0.18) was higher than in YTR(1.08 ± 0.05), MTR(1.13 ± 0.09), YUT(1.12 ± 0.09) (p < 0.05). It is concluded that recreationally trained women had faster V˙ O₂ kinetics along with better matching of O₂ delivery and utilization at the site of gas exchange in the exercising muscles.

Correlates and Determinants of Cardiorespiratory Fitness in Adults: a Systematic Review

Background

Enhanced cardiorespiratory fitness (CRF) is now a well-established predictor of numerous adverse health outcomes. Knowledge about the pathways leading to enhanced CRF is essential for developing appropriate interventions. Hence, the aim of this review was to provide a detailed overview of the current state of research regarding individual factors associated with or influencing CRF among the general adult population.

Methods

We searched the PubMed, EMBASE, and Cochrane Library databases and also conducted a search for grey literature (Google Scholar). Eligible indicators of CRF were objectively assessed measures of CRF by submaximal or maximal exercise testing measured using treadmill or cycle ergometer tests. We included quantitative observational studies of the general adult population. Using a semi-quantitative approach, we compiled summary tables aggregating the study results for each potential correlate or determinant of CRF.

Results

We identified 3005 studies, 78 of which met the inclusion criteria. Almost all of these studies were conducted in high-income countries. Study quality scores assessing the risk of bias in the individual studies ranged from 40 to 100%. Male sex, age (inverse), education, socioeconomic status, ethnicity, body mass index (inverse), body weight (inverse), waist circumference, body fat (inverse), resting heart rate (inverse), C-reactive protein (inverse), smoking (inverse), alcohol consumption, and multiple measures of leisure-time physical activity were independently and consistently associated with CRF.

Conclusions

In synthesizing the current research on the correlates and determinants of CRF among adults, this systematic review identified gaps in the current understanding of factors influencing CRF. Beyond the scope of this review, environmental and interpersonal determinants should be further investigated.

Systematic Review Registration

PROSPERO, CRD42017055456.

Electronic supplementary material

The online version of this article (10.1186/s40798-019-0211-2) contains supplementary material, which is available to authorized users.

Pulmonary oxygen uptake on-kinetics can predict acute physiological responses to resistance exercise training in healthy young men

PURPOSE

To clarify whether pulmonary oxygen uptake kinetics ( τ V ˙ O 2 p ) at the onset of moderate-intensity exercise can predict acute physiological responses to resistance exercise training (RET).

METHODS

We investigated the relationship between τ V ˙ O 2 p and acute metabolic and hemodynamic responses to a single RET session in 27 healthy young adult men. Cardiopulmonary exercise was on a cycle ergometer, and a single RET at 30% or 60% of one-repetition maximum was on a bilateral leg-extension machine. We measured the anaerobic threshold, peak V ˙ O 2 and τ V ˙ O 2 p while cardiopulmonary exercising, and the rates of increase in blood lactate (Bla), heart rate (HR), systolic blood pressure (SBP) and rate pressure product (RPP) for a single RET.

RESULTS

There were significant positive associations between τ V ˙ O 2 p and the rates of increase in Bla, HR, SBP and RPP during a single RET session (P<0·05). However, the anaerobic threshold and peak V ˙ O 2 did not significantly affect these parameters.

CONCLUSION

The τ V ˙ O 2 p is a useful evaluation index for predicting acute physiological responses to RET.

Association between skeletal muscle mass and cardiorespiratory fitness in community-dwelling elderly men

BACKGROUND

Sarcopenia reduces physical ability and cardiorespiratory fitness (CRF), leading to poor quality of life.

AIM

The aim of this study was to investigate the relationship between skeletal muscle mass and CRF in elderly men.

METHODS

We assessed 102 community-dwelling men over 60 years old. Appendicular skeletal muscle mass (ASM) was determined using bioelectrical impedance analysis, and the skeletal muscle mass index (SMI) was calculated as ASM divided by the square of height. Subjects with an SMI less than 7.0 kg/m² were included in the sarcopenic group, as recommended by the Asian Working Group for Sarcopenia. To investigate CRF parameters, a cardiopulmonary exercise test was performed using the Bruce protocol. CRF parameters were subdivided into aerobic capacity, cardiovascular response, and ventilatory response.

RESULTS

Of the 102 subjects, 15 (14.7%) were included in the sarcopenic group. There were significant correlations between SMI and peak oxygen consumption (VO_2peak) (r = 0.597, p < 0.001), and between SMI and VO_2peak/weight (r = 0.268, p = 0.024). Moreover, there were positive correlations between SMI and first ventilatory threshold (VT1) (r = 0.352, p = 0.008) and between SMI and VT1/weight (r = 0.189, p = 0.039). Additionally, peak oxygen pulse (O₂pulse_peak) was significantly correlated with SMI (r = 0.558, p < 0.001). VO_2peak, VO_2peak/weight and O₂pulse_peak showed significant differences between the sarcopenic and non-sarcopenic groups (p < 0.05, all). In multiple linear regression analyses, the factor related to VO_2peak was SMI (β = 0.473, p < 0.001) and that related to O₂pulse_peak was also SMI (β = 0.442, p < 0.001).

DISCUSSION AND CONCLUSIONS

This study demonstrated that skeletal muscle mass might be closely associated with CRF. Therefore, sarcopenia should be appropriately managed to improve an individual's CRF.

Association between activity energy expenditure and peak oxygen consumption with sarcopenia

Background

Sedentariness may be an important risk factor for sarcopenia. The aim of this work was to assess the association between muscle mass and strength and markers of usual physical activity such as activity energy expenditure and peak oxygen uptake.

Methods

Young and old participants were assessed measuring body composition by DEXA (double beam X ray absorptiometry), handgrip strength, peak oxygen consumption and workload during an exercise calorimetry in a braked cycle ergometer and a 72 h activity energy expenditure using Actiheart actigraphs. A heart rate/energy expenditure curve derived from the exercise calorimetry was used to calibrate each actigraph. Sarcopenia was defined as having an appendicular fat free mass index below 7.5 kg/m² and 5.6 kg/m² in men and women respectively, or a handgrip strength z score below 1, using local normal data or having both parameters below the cutoff points.

Results

We analyzed data from 192 assessments performed in participants aged 22 to 88 years (106 women). Sarcopenic participants (as determined by muscle mass, strength or both) had a significantly lower peak oxygen uptake and work load and a significantly lower activity energy expenditure. When analyzing lean mass and strength as continuous variables, peak oxygen consumption was a significant predictor of fat free mass in men. Among women, the association was observed only when percentage of muscle mass was expressed as a z score.

Conclusions

Activity energy expenditure and peak oxygen consumption are associated with a lower muscle mass and the presence of sarcopenia and should be considered as risk factors for this condition.

Applicability of ultrasonography for evaluating trunk muscle size: a pilot study

[Purpose] Ultrasonography (US) is widely applied to measure the muscle size in the limbs, as it has relatively high portability and is associated with low costs compared with large clinical devices such as magnetic resonance imaging (MRI). However, the applicability of US for evaluating trunk muscle size is poorly understood. This study aimed to examine whether US-measured muscle thickness (MT) in the trunk abdominal and back muscles correlated with MT and muscle cross-sectional area (MCSA) measured by MRI. [Subjects and Methods] Twenty-four healthy young males participated in this study. The MT and MCSA in the subjects were measured by US and MRI in a total of 10 sites, including the bilateral sides of the rectus abdominis (upper, central, and lower parts), abdominal wall, and multifidus lumborum. [Results] The interclass correlation coefficients of US-measured MT on the total 10 sites showed excellent values (n=12, 0.919 to 0.970). The US-measured MT significantly correlated with the MRI-measured MT (r=0.753 to 0.963) and MCSA (r=0.634 to 0.821). [Conclusion] US-measured MT could represent a surrogate for muscle size measured by MRI. The application of US for evaluating trunk muscle size may be a useful tool in the clinical setting.

Physical Exercise for Late-Life Depression: Customizing an Intervention for Primary Care

OBJECTIVES

To identify which individual- and context-related factors influence the translation into clinical practice of interventions based on physical exercise (PE) as an adjunct to antidepressants (AD) for the treatment of late-life major depression (LLMD).

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Primary care with psychiatric consultation-liaison programs (PCLPs)-organizational protocols that regulate the clinical management of individuals with psychiatric disorders.

PARTICIPANTS

Individuals aged 65 and older with major depression according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (N = 121).

INTERVENTION

Participants with LLMD were randomized to AD (sertraline) or AD plus PE (AD + PE).

MEASUREMENTS

Participant characteristics that were associated with greater effectiveness of AD + PE (moderators) were identified, and effect sizes were calculated from success rate differences. Whether the characteristics of the study setting influenced participant flow and attendance at exercise sessions was then explored, and primary care physicians (PCPs) were surveyed regarding their opinions on PE as a treatment for LLMD.

RESULTS

The following participant characteristics were associated with greater likelihood of achieving remission from depression with AD + PE than with AD alone: aged 75 and older (effect size 0.32), polypharmacy (0.35), greater aerobic capacity (0.48), displaying psychomotor slowing (0.49), and less-severe anxiety (0.30). The longer the PCLP had been established at a particular center, the more individuals were recruited at that center. After participating in the study, PCPs expressed positive views on AD + PE as a treatment for LLMD and were more likely to use this as a therapeutic strategy.

CONCLUSIONS

The combination of PE and sertraline could improve the management of LLMD, especially when customized for individuals with specific clinical features. Liaison programs might influence the implementation of similar interventions in primary care, and PCPs viewed them positively.

Intensity-specific effect of physical activity on urinary levels of 8-hydroxydeoxyguanosine in middle-aged Japanese

Physical activity (PA) is recommended to both promote and maintain health and prevent cancer by improving the body's DNA repair system, which is considered a mechanism of cancer prevention. However, associations between PA and urinary levels of 8-hydroxydeoxyguanosine (8-OH-dG), which reflects DNA damage, are unclear. This cross-sectional study included 2370 men and 4052 women aged 45-74 years enrolled between 2010 and 2012. Habitual PA was assessed by single-axis accelerometer and urinary 8-OH-dG levels by automated HPLC. Multiple linear regression analysis was used to examine the relationship between log-transformed urinary 8-OH-dG and total PA (TPA) and PA of moderate/vigorous intensity (MVPA; ≥3 metabolic equivalents), with adjustment for age, body mass index, energy intake, alcohol consumption, smoking status, daily coffee drinking, menopause status (in women), and TPA (for MVPA). On multivariate adjustment, urinary 8-OH-dG levels were inversely correlated with TPA (β = -0.020, P < 0.01) in women, and this correlation was not changed by PA intensity. Conversely, urinary 8-OH-dG levels were inversely correlated with MVPA (β = -0.022, P < 0.05) in men, although the correlation with TPA was non-significant. This inverse correlation was clearer in current smokers than in never or former smokers, although the interaction between smoking status and MVPA on urinary 8-OH-dG levels was non-significant. In conclusion, greater TPA in women and greater MVPA in men were correlated with reduction in urinary 8-OH-dG, suggesting sex-specific effects of MVPA and TPA on protection from oxidative DNA damage. Increasing PA may mediate reduction in oxidative stress.

Ultrasound-Derived Abdominal Muscle Thickness Better Detects Metabolic Syndrome Risk in Obese Patients than Skeletal Muscle Index Measured by Dual-Energy X-Ray Absorptiometry

Sarcopenia has never been diagnosed based on site-specific muscle loss, and little is known about the relationship between site-specific muscle loss and metabolic syndrome (MetS) risk factors. To this end, this cross-sectional study aimed to investigate the relationship between site-specific muscle size and MetS risk factors. Subjects were 38 obese men and women aged 40-82 years. Total body fat and lean body mass were assessed by whole-body dual-energy X-ray absorptiometry (DXA) scan. Muscle thickness (MTH) was measured using B-mode ultrasound scanning in six body regions. Subjects were classified into general obesity (GO) and sarcopenic obesity (SO) groups using the threshold values of one standard deviation below the sex-specific means of either MTH or skeletal muscle index (SMI) measured by DXA. MetS risk score was acquired by standardizing and summing the following continuously distributed variables: visceral fat area, mean blood pressure, HbA1c, and serum triglyceride / high density lipoprotein cholesterol, to obtain the Z-score. Multiple regression analysis revealed that the MetS risk score was independently associated with abdominal MTH in all subjects, but not with MTH in other muscle regions, including the thigh. Although HbA1c and the number of MetS risk factors in the SO group were significantly higher than those in the GO group, there were no significant differences between GO and SO groups as defined by SMI. Ultrasound-derived abdominal MTH would allow a better assessment of sarcopenia in obese patients and can be used as an alternative to the conventionally-used SMI measured by DXA.

Prospective study of physical activity and sleep in middle-aged and older adults

INTRODUCTION

Few prospective cohort studies have examined the association between physical activity (PA) and insomnia prevention, and the effective PA intensity remains unclear. This prospective study explores how PA intensity prevents incident short sleep duration and subjective insufficient sleep in middle-aged and older adults.

METHODS

A self-reported questionnaire gathered data on sleep and PA variables, including moderate low-intensity PA (MLPA); moderate high-intensity PA (MHPA); and vigorous-intensity PA (VPA), during health checkups conducted in Meiji Yasuda Shinjuku Medical Center in Tokyo. This study followed two cohorts from a 2008 baseline survey: (1) participants free of short sleep duration (n=7,061) and (2) participants free of insufficient sleep (n=7,385). They were divided into middle-aged (<60 years; 45.7 [8.8] years for sleep duration and 45.5 [8.8] years for sleep sufficiency) and older adults (both groups aged 65.3 [4.7] years) and followed for a mean 3.4 years until 2013. Data were analyzed in 2014.

RESULTS

Engaging in MHPA (hazard ratio [HR]=0.81, 95% CI=0.67, 0.98) and VPA (HR=0.83, 95% CI=0.71, 0.97) had a significant preventive effect on incident subjective insufficient sleep among middle-aged adults. For older adults, only MLPA (HR=0.58, 95% CI=0.42, 0.81) had a significant preventive effect on incident insufficient sleep, and PA did not significantly affect incident short sleep duration.

CONCLUSIONS

Middle-aged adults engaging in MHPA and VPA and older adults engaging in MLPA can effectively maintain sleep sufficiency. When providing an effective PA program to prevent insomnia, the intensity of PA should correspond to the participant's age.

Cardio-respiratory reference data in 4631 healthy men and women 20-90 years: the HUNT 3 fitness study

PURPOSE

To provide a large reference material on key cardio-respiratory variables in a healthy population of Norwegian men and women aged 20-90 years.

METHODS

Sub maximal and peak levels of cardio-respiratory variables were measured using cardiopulmonary exercise testing during treadmill running.

RESULTS

The highest peak ventilation among men (141.9±24.5 L·min-1) and women (92.0±16.5 L·min-1) was observed in the youngest age group (20-29 years, sex differences p<0.001) with an average 7% reduction per decade. The highest tidal volumes were observed in the 30-39 and 40-49 year age groups among men (2.94±0.46 L) and women (2.06±0.32 L) (sex differences p<0.001), with a subsequent average 6% reduction per decade. Ventilatory threshold and respiratory compensation point were observed at approximately 77% and 87% of peak oxygen uptake (VO2peak) among men and women, respectively. The best ventilatory efficiency (EqVCO2Than) was observed in the youngest age group (20-29 years) in both men (26.2±2.8) and woman (27.5±2.7) (sex differences p<0.001) with an average 3% deterioration in ventilatory efficiency per decade.

CONCLUSION

This is the largest European reference material of cardio-respiratory variables in healthy men and women aged 20-90 years, establishing normal values for, and associations between key cardio-respiratory parameters. This will be useful in clinical decision making when evaluating cardiopulmonary health in similar populations.

Maximal oxygen consumption in healthy humans: theories and facts

This article reviews the concept of maximal oxygen consumption ([Formula: see text]) from the perspective of multifactorial models of [Formula: see text] limitation. First, I discuss procedural aspects of [Formula: see text] measurement: the implications of ramp protocols are analysed within the theoretical work of Morton. Then I analyse the descriptive physiology of [Formula: see text], evidencing the path that led to the view of monofactorial cardiovascular or muscular [Formula: see text] limitation. Multifactorial models, generated by the theoretical work of di Prampero and Wagner around the oxygen conductance equation, represented a radical change of perspective. These models are presented in detail and criticized with respect to the ensuing experimental work. A synthesis between them is proposed, demonstrating how much these models coincide and converge on the same conclusions. Finally, I discuss the cases of hypoxia and bed rest, the former as an example of the pervasive effects of the shape of the oxygen equilibrium curve, the latter as a neat example of adaptive changes concerning the entire respiratory system. The conclusion is that the concept of cardiovascular [Formula: see text] limitation is reinforced by multifactorial models, since cardiovascular oxygen transport provides most of the [Formula: see text] limitation, at least in normoxia. However, the same models show that the role of peripheral resistances is significant and cannot be neglected. The role of peripheral factors is greater the smaller is the active muscle mass. In hypoxia, the intervention of lung resistances as limiting factors restricts the role played by cardiovascular and peripheral factors.

Effects of individualized exercise training in patients with catecholaminergic polymorphic ventricular tachycardia type 1

Ventricular arrhythmias (VAs) in patients with catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) are triggered at an individual and reproducible heart rate (HR) during exercise. Long-term effects of exercise on arrhythmia threshold in CPVT1 are not known. To investigate whether exercise training (ET) is feasible in patients with CPVT1, 13 patients with CPVT1 and confirmed genetic mutations performed bicycle exercise testing with maximal oxygen uptake (VO2max) measurements at baseline and after 13 weeks. The threshold HR for VA was defined as the HR when bigeminal ventricular extrasystoles or more severe VAs occurred. Six patients were enrolled in a 12-week high-intensity ergometer bicycle ET program (ET patients) with 60 min exercise sessions 3 times per week. The remaining 7 patients with CPVT1 were included as "sedentary" control (SED) patients complying with current recommendations to restrain from high-intensity physical activity. ET patients completed 28 ± 3 exercise sessions (78 ± 8% program completion) with 13 ± 3% increase in VO2max versus baseline (20.2 ± 1.6 vs 17.9 ± 1.3 ml/kg/min, p <0.05). No adverse events occurred. Baseline threshold for VA was 100 ± 6 beats/min in ET patients and 135 ± 4 beats/min in SED patients. After the training period, threshold HR for VA was 111 ± 10 beats/min in ET patients and 123 ± 6 beats/min in SED patients. The threshold for VA increased in ET compared with SED patients (+11 vs -12 beats/min, p <0.05). In conclusion, patients with CPVT1 benefitted from individualized ET with improved aerobic capacity and increased threshold HR for VA compared with SED patients.

Patterns of senescence in human cardiovascular fitness: VO2 max in subsistence and industrialized populations

OBJECTIVES

This study explores whether cardiovascular fitness levels and senescent decline are similar in the Tsimane of Bolivia and Canadians, as well as other subsistence and industrialized populations. Among Tsimane, we examine whether morbidity predicts lower levels and faster decline of cardiovascular fitness, or whether their lifestyle (e.g., high physical activity) promotes high levels and slow decline. Alternatively, high activity levels and morbidity might counterbalance such that Tsimane fitness levels and decline are similar to those in industrialized populations.

METHODS

Maximal oxygen uptake (VO2 max) was estimated using a step test heart rate method for 701 participants. We compared these estimates to the Canadian Health Measures Survey and previous studies in industrialized and subsistence populations. We evaluated whether health indicators and proxies for market integration were associated with VO2 max levels and rate of decline for the Tsimane.

RESULTS

The Tsimane have significantly higher levels of VO2 max and slower rates of decline than Canadians; initial evidence suggests differences in VO2 max levels between other subsistence and industrialized populations. Low hemoglobin predicts low VO2 max for Tsimane women while helminth infection predicts high VO2 max for Tsimane men, though results might be specific to the VO2 max scaling parameter used. No variables tested interact with age to moderate decline.

CONCLUSIONS

The Tsimane demonstrate higher levels of cardiovascular fitness than industrialized populations, but levels similar to other subsistence populations. The high VO2 max of Tsimane is consistent with their high physical activity and few indicators of cardiovascular disease, measured in previous studies.

Aerobic capacity reference data in 3816 healthy men and women 20-90 years

Purpose

To provide a large reference material on aerobic fitness and exercise physiology data in a healthy population of Norwegian men and women aged 20–90 years.

Methods

Maximal and sub maximal levels of VO₂, heart rate, oxygen pulse, and rating of perceived exertion (Borg scale: 6–20) were measured in 1929 men and 1881 women during treadmill running.

Results

The highest VO_2max and maximal heart rate among men and women were observed in the youngest age group (20–29 years) and was 54.4±8.4 mL·kg⁻¹·min⁻¹ and 43.0±7.7 mL·kg⁻¹·min⁻¹ (sex differences, p<0.001) and 196±10 beats·min⁻¹ and 194±9 beats·min⁻¹ (sex differences, p<0.05), respectively, with a subsequent reduction of approximately 3.5 mL·kg⁻¹·min⁻¹ and 6 beats·min⁻¹ per decade. The highest oxygen pulses were observed in the 3 youngest age groups (20–29 years, 30–39 years, 40–49 years) among men and women; 22.3 mL·beat⁻¹±3.6 and 14.7 mL·beat⁻¹±2.7 (sex differences, p<0.001), respectively, with no significant difference between these age groups. After the age of 50 we observed an 8% reduction per decade among both sexes. Borg scores appear to give a good estimate of the relative exercise intensity, although observing a slightly different relationship than reported in previous reference material from small populations.

Conclusion

This is the largest European reference material of objectively measured parameters of aerobic fitness and exercise-physiology in healthy men and women aged 20–90 years, forming the basis for an easily accessible, valid and understandable tool for improved training prescription in healthy men and women.

Sex differences in response to maximal exercise stress test in trained adolescents

Background

Sex comparisons between girls and boys in response to exercise in trained adolescents are missing and we investigated similarities and differences as a basis for clinical interpretation and guidance.

Methods

A total of 24 adolescent females and 27 adolescent males aged 13–19 years underwent a maximal bicycle exercise stress test with measurement of cardiovascular variables, cardiac output, lung volumes, metabolic factors/lactate concentrations and breath-by-breath monitoring of ventilation, and determination of peak VO₂.

Results

Maximum heart rate was similar in females (191 ± 9 bpm) and males (194 ± 7 bpm), cardiac index at maximum exercise was lower in females (7.0 ± 1.0 l/min/m²) than in males (8.3 ± 1.4 l/min/m², P < 0.05). Metabolic responses and RQ at maximum exercise were similar (females: 1.04 ± 0.06 vs. males: 1.05 ± 0.05). Peak VO₂ was lower in females (2.37 ± 0.34 l/min) than in males (3.38 ± 0.49 l/min, P < 0.05). When peak VO₂ was normalized to leg muscle mass sex differences disappeared (females: 161 ± 21 ml/min/kg vs. males: 170 ± 23 ml/min/kg). The increase in cardiac index during exercise is the key factor responsible for the greater peak VO₂ in adolescent boys compared to girls.

Conclusions

Differences in peak VO₂ in adolescent boys and girls disappear when peak VO₂ is normalized to estimated leg muscle mass and therefore provide a tool to conduct individual and intersex comparisons of fitness when evaluating adolescent athletes in aerobic sports.

The impact of different GFR estimating equations on the prevalence of CKD and risk groups in a Southeast Asian cohort using the new KDIGO guidelines

Background

Recently, the Kidney Disease: Improving Global Outcomes (KDIGO) group recommended that patients with CKD should be assigned to stages and composite relative risk groups according to GFR (G) and proteinuria (A) criteria. Asians have among the highest rates of ESRD in the world, but establishing the prevalence and prognosis CKD is a problem for Asian populations since there is no consensus on the best GFR estimating (eGFR) equation. We studied the effects of the choice of new Asian and Caucasian eGFR equations on CKD prevalence, stage distribution, and risk categorization using the new KDIGO classification.

Methods

The prevalence of CKD and composite relative risk groups defined by eGFR from with Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI); standard (S) or Chinese(C) MDRD; Japanese CKD-EPI (J-EPI), Thai GFR (T-GFR) equations were compared in a Thai cohort (n = 5526)

Results

There was a 7 fold difference in CKD_3-5 prevalence between J-EPI and the other Asian eGFR formulae. CKD_3-5 prevalence with S-MDRD and CKD-EPI were 2 - 3 folds higher than T-GFR or C-MDRD. The concordance with CKD-EPI to diagnose CKD_3-5 was over 90% for T-GFR or C-MDRD, but they only assigned the same CKD stage in 50% of the time. The choice of equation also caused large variations in each composite risk groups especially those with mildly increased risks. Different equations can lead to a reversal of male: female ratios. The variability of different equations is most apparent in older subjects. Stage G3aA1 increased with age and accounted for a large proportion of the differences in CKD_3-5 between CKD-EPI, S-MDRD and C-MDRD.

Conclusions

CKD prevalence, sex ratios, and KDIGO composite risk groupings varied widely depending on the equation used. More studies are needed to define the best equation for Asian populations.

Evaluation of anthropometric parameters and physical fitness in elderly Japanese

OBJECTIVES

We evaluated anthropometric parameters and physical fitness in elderly Japanese.

METHODS

A total of 2,106 elderly Japanese (749 men and 1,357 women), aged 60-79 years, were enrolled in a cross-sectional investigation study. Anthropometric parameters and physical fitness, i.e., muscle strength and flexibility, were measured. Of the 2,106 subjects, 569 subjects (302 men and 267 women) were further evaluated for aerobic exercise level, using the ventilatory threshold (VT).

RESULTS

Muscle strength in subjects in their 70s was significantly lower than that in subjects in their 60s in both sexes. Two hundred and twenty-nine men (30.6%) and 540 women (39.8%) were taking no medications. In men, anthropometric parameters were significantly lower and muscle strength, flexibility, and work rate at VT were significantly higher in subjects without medications than these values in subjects with medications. In women, body weight, body mass index (BMI), and abdominal circumference were significantly lower, and muscle strength was significantly higher in subjects without medications than these values in subjects with medications.

CONCLUSION

This mean value may provide a useful database for evaluating anthropometric parameters and physical fitness in elderly Japanese subjects.

Evaluation of ventilatory threshold and its relation to exercise habits among Japanese

OBJECTIVE

The aim of this study was to evaluate aerobic exercise levels, expressed in terms of ventilatory threshold (VT), in a Japanese population and explore the relationship between VT and exercise habits in this population.

METHODS

This was a cross-sectional study in which data collected from 547 men and 524 women aged 20-69 years and not on medications, were used to assess exercise habits and parameters at VT, namely, oxygen uptake, work rate, and heart rate.

RESULTS

Age-related changes in parameters at VT were noted. Of the participants, 205 men (37.5%) and 142 women (27.1%) had exercise habits. Oxygen uptake and work rate at VT in subjects with exercise habits were significantly higher than those without exercise habits after age had been adjusted for in both sexes. Anthropometric parameters were significantly correlated with oxygen uptake at VT, and the highest correlation coefficient rate was found between oxygen uptake at VT and body fat percentage (men r = -0.589, women r = -0.631).

CONCLUSION

The mean values determined here may provide a useful database for evaluating VT in Japanese adult subjects.

Revised equations for estimated GFR from serum creatinine in Japan

BACKGROUND

Estimation of glomerular filtration rate (GFR) is limited by differences in creatinine generation among ethnicities. Our previously reported GFR-estimating equations for Japanese had limitations because all participants had a GFR less than 90 mL/min/1.73 m2 and serum creatinine was assayed in different laboratories.

STUDY DESIGN

Diagnostic test study using a prospective cross-sectional design. New equations were developed in 413 participants and validated in 350 participants. All samples were assayed in a central laboratory.

SETTING & PARTICIPANTS

Hospitalized Japanese patients in 80 medical centers. Patients had not participated in the previous study.

REFERENCE TEST

Measured GFR (mGFR) computed from inulin clearance.

INDEX TEST

Estimated GFR (eGFR) by using the modified isotope dilution mass spectrometry (IDMS)-traceable 4-variable Modification of Diet in Renal Disease (MDRD) Study equation using the previous Japanese Society of Nephrology Chronic Kidney Disease Initiative (JSN-CKDI) coefficient of 0.741 (equation 1), the previous JSN-CKDI equation (equation 2), and new equations derived in the development data set: modified MDRD Study using a new Japanese coefficient (equation 3), and a 3-variable Japanese equation (equation 4).

MEASUREMENTS

Performance of equations was assessed by means of bias (eGFR - mGFR), accuracy (percentage of estimates within 15% or 30% of mGFR), root mean squared error, and correlation coefficient.

RESULTS

In the development data set, the new Japanese coefficient was 0.808 (95% confidence interval, 0.728 to 0.829) for the IDMS-MDRD Study equation (equation 3), and the 3-variable Japanese equation (equation 4) was eGFR (mL/min/1.73 m2) = 194 x Serum creatinine(-1.094) x Age(-0.287) x 0.739 (if female). In the validation data set, bias was -1.3 +/- 19.4 versus -5.9 +/- 19.0 mL/min/1.73 m2 (P = 0.002), and accuracy within 30% of mGFR was 73% versus 72% (P = 0.6) for equation 3 versus equation 1 and -2.1 +/- 19.0 versus -7.9 +/- 18.7 mL/min/1.73 m(2) (P < 0.001) and 75% versus 73% (P = 0.06) for equation 4 versus equation 2 (P = 0.06), respectively.

LIMITATION

Most study participants had chronic kidney disease, and some may have had changing GFRs.

CONCLUSION

The new Japanese coefficient for the modified IDMS-MDRD Study equation and the new Japanese equation are more accurate for the Japanese population than the previously reported equations.