Validation of a specific activity questionnaire to estimate exercise tolerance in patients referred for exercise testing

Effects of a Remote Multimodal Intervention Involving Diet, Walking Program, and Breathing Exercise on Quality of Life Among Newly Diagnosed People with Multiple Sclerosis: A Quasi-Experimental Non-Inferiority Pilot Study

Background

Interventions involving diet, physical activity, and breathing exercises are shown to be beneficial in managing both fatigue and quality of life (QoL) related to MS; however, the impact of such interventions among people newly diagnosed with clinically isolated syndrome (CIS) or relapsing-remitting multiple sclerosis (RRMS) who decline disease-modifying therapies (DMTs) is unknown.

Methods

A 12-month prospective quasi-experimental non-inferiority trial recruited people newly diagnosed with CIS or RRMS who voluntarily declined DMTs (health behavior group; HB, n = 29) or followed standard of care (SOC, n = 15). Participants in the HB group were remotely coached on the study diet, moderate-intensity walking, and breathing exercises. All participants completed questionnaires validated to assess MS symptoms, including perceived mental and physical QoL (MSQOL54); fatigue (Fatigue Severity Scale, FSS; and Modified Fatigue Impact Scale, MFIS); mood (Hospital Anxiety and Depression Scale, HADS); and cognitive function (Perceived Deficits Questionnaire, PDQ).

Results

During the 12 months, the HB group experienced improvement in scores for mental QoL (MSQOL54 - Mental, 0.24, 95% CI 0.01, 0.47; p = 0.04), fatigue (Total MFIS, -7.26, 95% CI -13.3,-1.18; p = 0.02), and perceived cognitive function (Total PDQ, PDQ-Attention, PDQ-Promemory, and PDQ-Planning, p ≤ 0.03 for all). A between-group difference was observed only for PDQ-Planning (p = 0.048). Non-inferiority analysis revealed that the 12-month changes in means for the HB group were not worse than those for the SOC group with respect to fatigue (FSS, p = 0.02), mood (HDS-Anxiety, p = 0.02; HADS-Depression, p < 0.0001), physical QoL (MSQOL54 - Physical, p = 0.02), or cognitive dysfunction (Total PDQ, p = 0.01).

Conclusion

The multimodal lifestyle intervention for individuals newly diagnosed with CIS or RRMS, who voluntarily decline DMTs, did not yield patient-reported outcomes worse than those observed in the SOC group regarding perceived mental quality of life, mood, fatigue, and cognitive function.

Trial Registration

clinicaltrials.gov identifier: NCT04009005.

Monitoring aerobic capacity in cancer survivors using self-reported questionnaires: criterion validity and responsiveness

BACKGROUND

Evaluating the criterion validity and responsiveness of the self-reported FitMáx©-questionnaire, Duke Activity Status Index (DASI) and Veterans Specific Activity Questionnaire (VSAQ) to monitor aerobic capacity in cancer survivors.

METHODS

Cancer survivors participating in a 10-week supervised exercise program were included. The FitMáx©-questionnaire, DASI, VSAQ and a cardiopulmonary exercise test (CPET) were completed before (T₀) and after (T₁) the program. Intraclass correlation coefficients (ICC) were calculated between VO_2peak estimated by the questionnaires (questionnaire-VO_2peak) and VO_2peak measured during CPET (CPET-VO_2peak), at T₀ to examine criterion validity, and between changes in questionnaire-VO_2peak and CPET-VO_2peak (ΔT₀-T₁) to determine responsiveness. Receiver operating characteristic (ROC) analyses were performed to examine the ability of the questionnaires to detect true improvements (≥ 6%) in CPET-VO_2peak.

RESULTS

Seventy participants were included. Outcomes at T₁ were available for 58 participants (83%). Mean CPET-VO_2peak significantly improved at T₁ (Δ1.6 mL·kg^- 1·min^- 1 or 8%). Agreement between questionnaire-VO_2peak and CPET-VO_2peak at T₀ was moderate for the FitMáx©-questionnaire (ICC = 0.69) and VSAQ (ICC = 0.53), and poor for DASI (ICC = 0.36). Poor agreement was found between ΔCPET-VO_2peak and Δquestionnaire-VO_2peak for all questionnaires (ICC 0.43, 0.19 and 0.18 for the FitMáx©-questionnaire, VSAQ and DASI, respectively). ROC analysis showed that the FitMáx©-questionnaire was able to detect improvements in CPET-VO_2peak (area under the curve, AUC = 0.77), when using a cut-off value of 1.0 mL·kg^- 1·min^- 1, while VSAQ (AUC = 0.66) and DASI (AUC = 0.64) could not.

CONCLUSION

The self-reported FitMáx©-questionnaire has sufficient validity to estimate aerobic capacity in cancer survivors at group level. The responsiveness of the FitMáx©-questionnaire for absolute change is limited, but the questionnaire is able to detect whether aerobic capacity improved. The FitMáx©-questionnaire showed substantial better values of validity and responsiveness compared to DASI and VSAQ.

Three-Month Variability of Commonly Evaluated Biomarkers in Clinically Stable COPD

Introduction

Clinical decisions in chronic obstructive pulmonary disease (COPD) treatment often utilize serially assessed physiologic parameters and biomarkers. To better understand the reliability of these tests, we evaluated changes in commonly assessed biomarkers over 3 months in patients with clinically stable COPD.

Methods

We performed an observational prospective cohort study of 89 individuals with clinically stable COPD, defined as no exacerbation history within 3 months of enrollment. Biomarkers included lung function and functional performance status, patient-reported outcomes of symptoms and health status, and blood markers of inflammation. The correlation between testing at baseline and at 3-month follow-up was reported as the intraclass correlation coefficient (ICC). "Outliers" had significant variability between tests, defined as >1.645 standard deviations between the two measurements. Differences in clinical features between outliers and others were compared.

Results

Participants with COPD (n = 89) were 70.5 ± 6.7 years old, 54 (61%) male, had a 40 pack-year smoking history with 24.7% being current smokers, and postbronchodilator forced expiratory volume in one second (FEV1) 62.3 ± 22.7% predicted. The biomarkers with excellent agreement between the initial and the follow-up measurements were FEV1 (ICC = 0.96), Saint George's Respiratory Questionnaire (SGRQ) (ICC = 0.98), COPD Assessment Test (CAT) (ICC = 0.93) and C-reactive protein (CRP) (ICC = 0.90). By contrast, parameters showing less robust agreement were 6-minute walking distance (ICC = 0.75), eosinophil count (ICC = 0.77), erythrocyte sedimentation rate (ICC = 0.75) and white blood cell count (ICC = 0.48). Individuals with greater variability in biomarkers reported chronic bronchitis more often and had higher baseline SGRQ and CAT scores.

Conclusion

Our study evaluated the stability of commonly assessed biomarkers in clinically stable COPD and showed excellent agreement between baseline and three-month follow-up values for FEV1, SGRQ, CAT and CRP. Individuals with chronic bronchitis and more symptomatic disease at baseline demonstrated greater variability in 3-month interval biomarkers.

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Use of a Wearable Biosensor to Study Heart Rate Variability in Chronic Obstructive Pulmonary Disease and Its Relationship to Disease Severity

The purpose of this study was to explore the relationships between heart rate variability (HRV) and various phenotypic measures that relate to health and functional status in chronic obstructive pulmonary disease (COPD), and secondly, to demonstrate the feasibility of ascertaining HRV via a chest-worn wearable biosensor in COPD patients. HRV analysis was performed using SDNN (standard deviation of the mean of all normal R-R intervals), low frequency (LF), high frequency (HF), and LF/HF ratio. We evaluated the associations between HRV and COPD severity, class of bronchodilator therapy prescribed, and patient reported outcomes. Seventy-nine participants with COPD were enrolled. There were no differences in SDNN, HF, and LF/HF ratio according to COPD severity. The SDNN in participants treated with concurrent beta-agonists and muscarinic antagonists was lower than that in other participants after adjusting heart rate (beta coefficient −3.980, p = 0.019). The SDNN was positively correlated with Veterans Specific Activity Questionnaire (VSAQ) score (r = 0.308, p = 0.006) and handgrip strength (r = 0.285, p = 0.011), and negatively correlated with dyspnea by modified Medical Research Council (mMRC) questionnaire (r = −0.234, p = 0.039), health status by Saint George’s Respiratory Questionnaire (SGRQ) (r = −0.298, p = 0.008), symptoms by COPD Assessment Test (CAT) (r = −0.280, p = 0.012), and BODE index (r = −0.269, p = 0.020). When measured by a chest-worn wearable device, reduced HRV was observed in COPD participants receiving inhaled beta-sympathomimetic agonist and muscarinic antagonists. HRV was also correlated with various health status and performance measures.

Association of physical function and performance with peak VO2 in elderly patients with end stage kidney disease

BACKGROUND

Physical function is impaired in end stage renal disease (ESRD). Various instruments have been used to assess the functional capabilities and health status of patients with ESRD, but it is not known which has the best association with peak VO₂.

AIMS

To assess the association between functional measures in ESRD.

METHODS

Thirty nine elderly ESRD patients were evaluated with commonly used functional, health status, and quality of life measures, including maximal cardiopulmonary exercise testing (CPET), 6-min walk (6MWT), sit-to-stand test (STS), Veterans Specific Activity Questionnaire (VSAQ), upper and lower body strength, pulmonary function tests, and body composition determined by dual X-ray absorptiometry. The association between performance on these functional tools, clinical variables, and exercise test responses was assessed, and a non-exercise test multivariate model was developed to predict peak VO₂.

RESULTS

Peak VO₂ was modestly related to VSAQ score (r = 0.59, p < 0.01), indices of upper and lower body strength (r = 0.45, p < 0.01 for both), and FEV₁ (r = 0.51, p < 0.01). Functional and quality of life questionnaires were generally poorly related to one another and to peak VO₂. In a multivariate model, 6MWT performance, forced expiratory volume in 1 s (FEV₁), and VSAQ score were the best predictors of peak VO₂, yielding a multiple R = 0.82, accounting for 67% of the variance in peak VO₂.

CONCLUSION

Exercise capacity can be reasonably estimated using non-exercise test variables in patients with ESRD, including a symptom questionnaire (VSAQ), 6MWT and FEV₁.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov identifier: NCT01990495. Registered Nov 21, 2013.

Differential Evaluating Effect on Exercise Capacity of Cardiopulmonary Exercise Testing and Treadmill Exercise Testing in Post-percutaneous Coronary Intervention Patients

Background: Treadmill exercise testing (TET) is commonly used to measure exercise capacity. Studies have shown that cardiopulmonary exercise testing (CPET) is more accurate than TET and is, therefore, regarded as the "gold standard" for testing maximum exercise capacity and prescribing exercise plans. To date, no studies have reported the differences in exercise capacity after percutaneous coronary intervention (PCI) using the two methods or how to more accurately measure exercise capacity based on the results of TET. Aims: This study aims to measure maximum exercise capacity in post-PCI patients and to recommend exercise intensities that ensure safe levels of exercise. Methods: We enrolled 41 post-PCI patients who were admitted to the Cardiac Rehabilitation Clinic at the First Medical Center, the Chinese PLA General Hospital, from July 2015 to June 2016. They completed CPET and TET. The paired sample t-test was used to compare differences in measured exercise capacity, and multiple linear regression was applied to analyze the factors that affected the difference. Results: The mean maximum exercise capacity measured by TET was 8.89 ± 1.53 metabolic equivalents (METs), and that measured by CPET was 5.19 ± 1.23 METs. The difference between them was statistically significant (p = 0.000) according to the paired sample t-test. The difference averaged 40.15% ± 2.61% of the exercise capacity measured by TET multiple linear regression analysis showed that the difference negatively correlated with waist-hip ratio (WHR). Conclusion: For the purpose of formulating more accurate exercise prescription, the results of TET should be appropriately adjusted when applied to exercise capacity assessment. Clinical Trial Registration:http://www.chictr.org.cn/ number, ChiCTR2000031543.

Age-Dependent Associations Between 25-Hydroxy Vitamin D Levels and COPD Symptoms: Analysis of SPIROMICS

INTRODUCTION

Age and vitamin D levels may affect symptom burden in chronic obstructive pulmonary disease (COPD). We used the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) to determine independent associations between vitamin D levels and COPD symptoms in different age strata.

METHODS

Serum 25-hydroxy (OH)-vitamin D levels were modeled continuously and categorically (<20 ng/ml versus ≥20 ng/ml). Stratifying by age group (middle-age: 40-64 years old and older: >65 years old), multivariable modeling was performed to identify relationships between 25-OH-vitamin D levels and the COPD Assessment Test (CAT), the modified Medical Research Council score (mMRC), the St George's Respiratory Questionnaire (SGRQ) total and subdomain scores, the Veterans' Specific Activity Questionnaire, and the 6-minute walk test distance.

RESULTS

InIn the middle-aged group, each 5 ng/ml higher 25-OH-vitamin D level was independently associated with more favorable CAT score (-0.35 [-0.67 to -0.03], P=0.03), total SGRQ (-0.91 [-1.65 to -0.17]; P=0.02), and the SGRQ subdomains (Symptoms:-1.07 [-1.96 to -0.18], P=0.02; Impact: -0.77 [-1.53 to -0.003], P=0.049; Activity: -1.07 [-1.96 to -0.18], P=0.02). These associations persisted after the addition of comorbidity score, reported vitamin D supplementation, outdoor time, or season of blood draw to models. No associations were observed between 25-OH-vitamin D levels and symptom scores in the older age group.

DISCUSSION

When controlled for clinically relevant covariates, higher 25-OH-vitamin D levels are associated with more favorable respiratory-specific symptoms and quality-of-life assessments in middle-age but not older COPD individuals. Study of the role of vitamin D supplementation in the symptom burden of younger COPD patients is needed.

Influence of Different Treadmill Inclinations on V̇o2max and Ventilatory Thresholds During Maximal Ramp Protocols

ABSTRACT

Silva, SC, Monteiro, WD, Cunha, FA, and Farinatti, P. Influence of different treadmill inclinations on V̇o2max and ventilatory thresholds during maximal ramp protocols. J Strength Cond Res 35(1): 233-239, 2021-Ramp protocols for cardiopulmonary exercise testing (CPET) lack precise recommendations, including optimal treadmill inclination. This study investigated the impact of treadmill grades applied in ramp CPETs on maximal oxygen uptake (V̇o2max), ventilatory thresholds (VT1/VT2), and V̇o2 vs. workload relationship. Twenty-one healthy men (age 33 ± 8 years; height 176.6 ± 5.8 cm; body mass 80.4 ± 8.7 kg; and V̇o2max 44.9 ± 5.7 ml·kg-1·min-1) and 12 women (age 29 ± 7 years; height 163.3 ± 6.7 cm; body mass 56.6 ± 6.3 kg; and V̇o2max 39.4 ± 4.9 ml·kg-1·min-1) underwent ramp CPETs with similar speed increments and different treadmill grades: CPET0%, CPET2%, CPET3.5%, and CPET5.5%. The V̇o2max was similar across protocols (42.8-43.2 ml·kg-1·min-1, p = 0.76), albeit duration of CPETs shortened when treadmill inclination increased (CPET0% 12.7 minutes; CPET2% 9.1 minutes; CPET3.5% 8.0 minutes; and CPET5.5% 6.6 minutes; p < 0.01). The %V̇o2max corresponding to VT1 was slightly lower in CPET0% (63.6%) and higher in CPET5.5% (75.8%) vs. CPET2% (67.8%) and CPET3.5% (69.5%; p < 0.05), whereas VT2 was not affected by treadmill inclination (95.1-95.8% V̇o2max; p > 0.05). V̇o2max and ventilatory thresholds were similar in CPETs performed with different treadmill inclinations and similar initial/final speeds. However, linear regressions between workload and V̇o2 were closer to the identity line in CPETs performed with smaller (CPET0% and CPET2%) than with greater (CPET3.5% and CPET5.5%) inclinations. These data suggest that in healthy young adults, ramp CPETs performed with inclinations of 0-2% degree should be preferred over protocols with greater inclinations.

Novel Respiratory Disability Score Predicts COPD Exacerbations and Mortality in the SPIROMICS Cohort

Rationale

Some COPD patients develop extreme breathlessness, decreased exercise capacity and poor health status yet respiratory disability is poorly characterized as a distinct phenotype.

Objective

To define respiratory disability in COPD based on available functional measures and to determine associations with risk for exacerbations and death.

Methods

We analyzed baseline data from a multi-center observational study (SPIROMICS). This analysis includes 2332 participants (472 with severe COPD, 991 with mild/moderate COPD, 726 smokers without airflow obstruction and 143 non-smoking controls).

Measurements

We defined respiratory disability by ≥4 of 7 criteria: mMRC dyspnea scale ≥3; Veterans Specific Activity Questionnaire <5; 6-minute walking distance <250 m; St George’s Respiratory Questionnaire activity domain >60; COPD Assessment Test >20; fatigue (FACIT-F Trial Outcome Index) <50; SF-12 <20.

Results

Using these criteria, respiratory disability was identified in 315 (13.5%) participants (52.1% female). Frequencies were severe COPD 34.5%; mild-moderate COPD 11.2%; smokers without obstruction 5.2% and never-smokers 2.1%. Compared with others, participants with disability had more emphysema (13.2 vs. 6.6%) and air-trapping (37.0 vs. 21.6%) on HRCT (P<0.0001). Using principal components analysis to derive a disability score, two factors explained 71% of variance, and a cut point −1.0 reliably identified disability. This disability score independently predicted future exacerbations (ß=0.34; CI 0.12, 0.64; P=0.003) and death (HR 2.97; CI 1.54, 5.75; P=0.001). Thus, participants with disability by this criterion had almost three times greater mortality compared to those without disability.

Conclusion

Our novel SPIROMICS respiratory disability score in COPD was associated with worse airflow obstruction as well as airway wall thickening, lung parenchymal destruction and certain inflammatory biomarkers. The disability score also proved to be an independent predictor of future exacerbations and death. These findings validate disability as an important phenotype in the spectrum of COPD.

[Measuring physical fitness in the German National Cohort-methods, quality assurance, and first descriptive results]

Physical fitness is defined as an individual's ability to be physically active. The main components are cardiorespiratory fitness (CRF), muscle strength, and flexibility. Regardless of physical activity level, physical fitness is an important determinant of morbidity and mortality.The aim of the current study was to describe the physical fitness assessment methodology in the German National Cohort (NAKO) and to present initial descriptive results in a subsample of the cohort.In the NAKO, hand grip strength (GS) and CRF as physical fitness components were assessed at baseline using a hand dynamometer and a submaximal bicycle ergometer test, respectively. Maximum oxygen uptake (VO_2max) was estimated as a result of the bicycle ergometer test. The results of a total of 99,068 GS measurements and 3094 CRF measurements are based on a data set at halftime of the NAKO baseline survey (age 20-73 years, 47% men).Males showed higher values of physical fitness compared to women (males: GS = 47.8 kg, VO_2max = 36.4 ml·min^-1 · kg^-1; females: GS = 29.9 kg, VO_2max = 32.3 ml · min^-1 · kg^-1). GS declined from the age of 50 onwards, whereas VO_2max levels decreased continuously between the age groups of 20-29 and ≥60 years. GS and VO_2max showed a linear positive association after adjustment for body weight (males β = 0.21; females β = 0.35).These results indicate that the physical fitness measured in the NAKO are comparable to other population-based studies. Future analyses in this study will focus on examining the independent relations of GS and CRF with risk of morbidity and mortality.

High-intensity interval training reduces monocyte activation in obese adults

Alterations in the distribution and activation of monocyte subsets are frequently observed in individuals with obesity and their participation in the pathological complications of obesity is proposed. High-intensity interval training (HIIT) can be a time-efficient alternative to counteract the inflammatory outcomes of obesity, but so far, its effects on monocytes in obesity has not been fully explored. In this study, we investigated whether 8 weeks of HIIT can modify the distribution and activation of the three monocyte subsets (classical, intermediate and non-classical monocytes) in individuals with obesity. Our data show that individuals with obesity have a higher percentage of non-classical monocytes compared to control, lean individuals, and consequently an imbalance among the CD16⁺ monocyte subsets. Also, the expression of HLA-DR by intermediate monocytes is higher in insulin-resistant obese individuals, which indicates monocyte activation in obesity. After 8 weeks of HIIT, the percentage of non-classical monocytes was reduced in individuals with obesity, restoring the balance among the CD16⁺ monocytes. Also, the expression of HLA-DR by intermediate monocytes in insulin-resistant obese subjects was lower after HIIT. Both findings indicate that monocyte activation in individuals with obesity was reduced by HIIT. These modifications were observed in the absence of changes in weight and body composition, although they were accompanied by the improvement in the metabolic status (reduced insulin levels). Our findings indicate that HIIT can be considered a time-efficient strategy to manage obesity-related monocyte alterations and strengthen the immunomodulatory potential of HIIT.

Exercise capacity reflects airflow limitation rather than hypoxaemia in patients with pulmonary arteriovenous malformations

BACKGROUND

Pulmonary arteriovenous malformations (PAVMs) generate a right-to-left shunt. Impaired gas exchange results in hypoxaemia and impaired CO2 clearance. Most patients compensate effectively but some are dyspneic, and these are rarely the most hypoxaemic.

AIM

To test degrees of concurrent pathology influencing exercise capacity.

DESIGN

Replicate, sequential single centre, prospective studies.

METHODS

Cardiopulmonary exercise tests (CPETs) were performed in 26 patients with PAVMs, including individuals with and without known airflow obstruction. To replicate, relationships were tested prospectively in an independent cohort where self-reported exercise capacity evaluated by the Veterans Specific Activity Questionnaire (VSAQ) was used to calculate metabolic equivalents (METs) at peak exercise (n = 71). Additional measurements included oxygen saturation (SpO2), forced expiratory volume in 1 s (FEV1), vital capacity (VC), fractional exhaled nitric oxide (FeNO), haemoglobin and iron indices.

RESULTS

By CPET, the peak work rate was only minimally associated with low SpO2 or low arterial oxygen content (calculated as CaO2=1.34 × SpO2 × haemoglobin), but was reduced in patients with low FEV1 or VC. Supranormal work rates were seen in patients with severe right-to-left shunting and SpO2 < 90%, but only if FEV1 was >80% predicted. VSAQ-calculated METS also demonstrated little relationship with SpO2, and in crude and CaO2-adjusted regression, were lower in patients with lower FEV1 or VC. Bronchodilation increased airflow even where spirometry was in the normal range: exhaled nitric oxide measurements were normal in 80% of cases, and unrelated to any PAVM-specific variable.

CONCLUSIONS

Exercise capacity is reduced by relatively mild airflow limitation (obstructive or restrictive) in the setting of PAVMs.

A longitudinal big data approach for precision health

Precision health relies on the ability to assess disease risk at an individual level, detect early preclinical conditions and initiate preventive strategies. Recent technological advances in omics and wearable monitoring enable deep molecular and physiological profiling and may provide important tools for precision health. We explored the ability of deep longitudinal profiling to make health-related discoveries, identify clinically relevant molecular pathways and affect behavior in a prospective longitudinal cohort (n = 109) enriched for risk of type 2 diabetes mellitus. The cohort underwent integrative personalized omics profiling from samples collected quarterly for up to 8 years (median, 2.8 years) using clinical measures and emerging technologies including genome, immunome, transcriptome, proteome, metabolome, microbiome and wearable monitoring. We discovered more than 67 clinically actionable health discoveries and identified multiple molecular pathways associated with metabolic, cardiovascular and oncologic pathophysiology. We developed prediction models for insulin resistance by using omics measurements, illustrating their potential to replace burdensome tests. Finally, study participation led the majority of participants to implement diet and exercise changes. Altogether, we conclude that deep longitudinal profiling can lead to actionable health discoveries and provide relevant information for precision health.

Modern Innovative Solutions to Improve Outcomes in Asthma, Breathlessness, and Chronic Obstructive Pulmonary Disease (MISSION ABC): Protocol for a Mixed-Methods Study

BACKGROUND

A high proportion of the costs for respiratory diseases are generated by a relatively small group of patients with severe disease (recognized or unrecognized) or complex problems that include multimorbidity, at-risk behaviors, and socioeconomic disadvantage. These patients often struggle to engage with the structured, proactive, care approaches for chronic disease management advocated for asthma and chronic obstructive pulmonary disease (COPD), resulting in repeated emergency use of both primary and secondary health care. An integrated approach for the management of complex patients, incorporating both specialist and primary care teams' expertise, may be effective in improving outcomes for such high-risk patients. However, the evidence is mixed, and there is a need for evaluation of models of integrated care in routine "real-world" clinical settings.

OBJECTIVE

This mixed-methods protocol examines the implementation of a novel integrated care model for patients with airways disease and undifferentiated breathlessness by using both quantitative and qualitative evaluation of processes, patient and health care professional experiences, and clinical outcomes throughout the clinic cycles. It aims to establish whether Modern Innovative Solutions to Improve Outcomes in Asthma, Breathlessness, and Chronic Obstructive Pulmonary Disease (MISSION ABC), including innovative diagnostic and self-management tools, can deliver improvements in health service use and clinical outcomes for the different patient groups (asthma, breathlessness, and COPD) and compares the 12-month period prior to the first patient visit and the 6-month period following the last visit.

METHODS

A combination of study designs is required to evaluate all aspects of the service: participatory action research approach, involving real-time evaluation at each clinic to inform subsequent clinics; before-and-after study for patient outcomes before and after clinic attendance; and qualitative methods (interviews and focus groups).

RESULTS

The results will be compiled and published in April 2019.

CONCLUSIONS

Evaluation of the clinic cycles will include consideration of qualitative data from patients, carers, and health care professionals in addition to quantitative outcomes for service implementation and patient factors. The long-term impact of the service will be evaluated using clinical and health service outcomes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/9228.

Metabolic Equivalent Values of Common Daily Activities in Middle-Age and Older Adults in Free-Living Environments: A Pilot Study

BACKGROUND

The purpose was to assess metabolic equivalent (MET) values of common daily activities in middle-age and older adults in free-living environments and compare these with MET values listed in the compendium of physical activities (CPA).

METHODS

Sixty participants (mean age = 71.5, SD = 10.8) completed a semistructured protocol of sitting, lying, self-paced walking, and 4 self-selected activities in their residences. Oxygen consumption was measured using portable indirect calorimetry, to assess METs for each activity relative to VO₂ at rest (VO₂ during activity/VO₂ at rest). Measured MET values for 20 different activities were compared with those in the CPA, for the total sample and for participants aged 55-64, 65-74, and 75-99 years.

RESULTS

Measured METs for sitting, walking, sweeping, trimming, and laundry were significantly different from the CPA values. Measured MET values for sedentary activities were lower in all age groups, and those for walking and household activities were higher in the youngest age group, than the CPA values. For gardening activities, there was a significant decline in measured METs with age.

CONCLUSIONS

Some measured MET values in older people differed from those in the CPA. The values reported here may be useful for future research with younger, middle-age, and older-old people.

Veterans Specific Activity Questionnaire (VSAQ): a new and efficient method of assessing exercise capacity in patients with pulmonary arteriovenous malformations

Introduction

Assessment of performance status is an important component of clinical management of patients with pulmonary arteriovenous malformations (PAVMs). Usual methods are time-consuming and insensitive to variations within normal or supranormal exercise capacity.

Methods

The Veterans Specific Activity Questionnaire (VSAQ) was modified to facilitate completion by patients independently. Patient-reported activity limitations were converted to the Medical Research Council (MRC) Dyspnoea Scale, New York Heart Association (NYHA) classification and metabolic equivalents (METs) in which 1 MET equals the consumption of 3.5 mL O₂ per kilogram of body weight per minute.

Results

The study population consisted of 71 patients with PAVMs aged 20-85 (median 52) years. Oxygen saturation (SaO₂) was 80%-99.5 % (median 96%), and haemoglobin was 73-169 g/L in women and 123-197 g/L in men (p<0.0001). Arterial oxygen content (CaO₂) (1.34 × [haemoglobin × SaO₂]/100) was maintained unless iron deficiency was present. Most patients (49/71, 69%) did not need to stop until activities more energetic than walking briskly at 4 mph were achieved (6.4 km per hour, VSAQ >5, MRC Dyspnoea Scale 1 or 2, NYHA class I). SaO₂ was inversely associated with the MRC Dyspnoea Scale and NYHA class, but not the VSAQ. Raw VSAQ scores captured a marked difference between men and women. METs were also higher in men at 3.97-15.55 (median 8.84) kcal/kg/min, compared with 1.33-14.4 (median 8.25) kcal/kg/min (p=0.0039). There was only a modest association between METs and SaO₂ (p=0.044), but a stronger association between METs and haemoglobin (p =0.001). In crude and sex-adjusted regression, the CaO₂ was more strongly associated with METs than either SaO₂ or haemoglobin in isolation.

Conclusion

The VSAQ, capturing patient-reported outcome measures, is an efficient and quantifiable measure of exercise capacity that can be readily employed in clinical services particularly where patients have normal to high exercise tolerance. In the PAVM population, exercise capacity reflects haemoglobin and CaO₂ more than SaO₂, even where SaO₂ measurements are low.

Dietary approaches to treat MS-related fatigue: comparing the modified Paleolithic (Wahls Elimination) and low saturated fat (Swank) diets on perceived fatigue in persons with relapsing-remitting multiple sclerosis: study protocol for a randomized controlled trial

BACKGROUND

Fatigue is one of the most disabling symptoms of multiple sclerosis (MS) and contributes to diminishing quality of life. Although currently available interventions have had limited success in relieving MS-related fatigue, clinically significant reductions in perceived fatigue severity have been reported in a multimodal intervention pilot study that included a Paleolithic diet in addition to stress reduction, exercise, and electrical muscle stimulation. An optimal dietary approach to reducing MS-related fatigue has not been identified. To establish the specific effects of diet on MS symptoms, this study focuses on diet only instead of the previously tested multimodal intervention by comparing the effectiveness of two dietary patterns for the treatment of MS-related fatigue. The purpose of this study is to determine the impact of a modified Paleolithic and low saturated fat diet on perceived fatigue (primary outcome), cognitive and motor symptoms, and quality of life in persons with relapsing-remitting multiple sclerosis (RRMS).

METHODS/DESIGN

This 36-week randomized clinical trial consists of three 12-week periods during which assessments of perceived fatigue, quality of life, motor and cognitive function, physical activity and sleep, diet quality, and social support for eating will be collected. The three 12-week periods will consist of the following: 1.

OBSERVATION

Participants continue eating their usual diet. 2.

INTERVENTION

Participants will be randomized to a modified Paleolithic or low saturated fat diet for the intervention period. Participants will receive support from a registered dietitian (RD) through in-person coaching, telephone calls, and emails. 3.

FOLLOW-UP

Participants will continue the study diet for an additional 12 weeks with minimal RD support to assess the ability of the participants to sustain the study diet on their own.

DISCUSSION

Because fatigue is one of the most common and disabling symptoms of MS, effective management and reduction of MS-related fatigue has the potential to increase quality of life in this population. The results of this study will add to the evidence base for providing dietary recommendations to treat MS-related fatigue and other symptoms associated with this disease.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02914964 . Registered on 24 August 2016.

A Longitudinal Study Examining the Change in Functional Independence Over Time in Elderly Individuals With a Functioning Kidney Transplant

Background:

Functional disability is defined as the need for assistance with self-care tasks.

Objective:

To document changes in functional status over time among older prevalent renal transplant recipients.

Design:

Single center, prospective, follow-up study.

Setting:

Single center, tertiary care transplant center.

Patients:

Patients, with a functioning kidney transplant, aged 65 years or older who underwent assessment of functional status approximately 12 months previously.

Measurements:

Validated tools used included Barthel Index, the Lawton-Brody Scale of Instrumental Activities of Daily Living, the Timed Up and Go test, the Veterans Specific Activity Questionnaire, the Mini-Cog, and dynamometer handgrip strength.

Methods:

Outpatient assessment by a trained observer.

Results:

Of the 82 patients previously studied, 64 (78%) patients participated in the follow-up study (mean age 70.5 ± 4.4 years, 58% male, 55% diabetic). Among those completing functional status measures, 32 (50%) had functional disability at baseline. Over the 1-year period, 11 (17%) of these patients experienced progressive functional decline, 6 (9%) exhibited no change, and 15 (23%) had functional recovery. Eleven patients (17%) initially independent, developed new-onset disability. One of the strongest predictors of progressive functional decline was having 1 or more falls in the previous year.

Limitations:

Assessments were performed only on 2 occasions separated by approximately 1 year.

Conclusions:

Fluctuations in disability states are common among older adults living with renal transplants. Episodes of functional disability may place individuals at higher risk of persistent and/or progressive disability.

Respiratory Symptoms Items from the COPD Assessment Test Identify Ever-Smokers with Preserved Lung Function at Higher Risk for Poor Respiratory Outcomes. An Analysis of the Subpopulations and Intermediate Outcome Measures in COPD Study Cohort

RATIONALE

Ever-smokers without airflow obstruction scores greater than or equal to 10 on the COPD Assessment Test (CAT) still have frequent acute respiratory disease events (exacerbation-like), impaired exercise capacity, and imaging abnormalities. Identification of these subjects could provide new opportunities for targeted interventions.

OBJECTIVES

We hypothesized that the four respiratory-related items of the CAT might be useful for identifying such individuals, with discriminative ability similar to CAT, which is an eight-item questionnaire used to assess chronic obstructive pulmonary disease impact, including nonrespiratory questions, with scores ranging from 0 to 40.

METHODS

We evaluated ever-smoker participants in the Subpopulations and Intermediate Outcomes in COPD Study without airflow obstruction (FEV₁/FVC ≥0.70; FVC above the lower limit of normal). Using the area under the receiver operating characteristic curve, we compared responses to both CAT and the respiratory symptom-related CAT items (cough, phlegm, chest tightness, and breathlessness) and their associations with longitudinal exacerbations. We tested agreement between the two strategies (κ statistic), and we compared demographics, lung function, and symptoms among subjects identified as having high symptoms by each strategy.

RESULTS

Among 880 ever-smokers with normal lung function (mean age, 61 yr; 52% women) and using a CAT cutpoint greater than or equal to 10, we classified 51.8% of individuals as having high symptoms, 15.3% of whom experienced at least one exacerbation during 1-year follow-up. After testing sensitivity and specificity of different scores for the first four questions to predict any 1-year follow-up exacerbation, we selected cutpoints of 0-6 as representing a low burden of symptoms versus scores of 7 or higher as representing a high burden of symptoms for all subsequent comparisons. The four respiratory-related items with cutpoint greater than or equal to 7 selected 45.8% participants, 15.6% of whom experienced at least one exacerbation during follow-up. The two strategies largely identified the same individuals (agreement, 88.5%; κ = 0.77; P < 0.001), and the proportions of high-symptoms subjects who had severe dyspnea were similar between CAT and the first four CAT questions (25.9% and 26.8%, respectively), as were the proportions reporting impaired quality of life (66.9% and 70.5%, respectively) and short walking distance (22.4% and 23.1%, respectively). There was no difference in area under the receiver operating characteristic curve to predict 1-year follow-up exacerbations (CAT score ≥10, 0.66; vs. four respiratory items from CAT ≥7 score, 0.65; P = 0.69). Subjects identified by either method also had more depression/anxiety symptoms, poor sleep quality, and greater fatigue.

CONCLUSIONS

Four CAT items on respiratory symptoms identified high-risk symptomatic ever-smokers with preserved spirometry as well as the CAT did. These data suggest that simpler strategies can be developed to identify these high-risk individuals in primary care.

Randomized control trial evaluation of a modified Paleolithic dietary intervention in the treatment of relapsing-remitting multiple sclerosis: a pilot study

BACKGROUND/OBJECTIVE

A Paleolithic diet may improve fatigue and quality of life in progressive multiple sclerosis (MS) patients, but past research has evaluated the effects of this dietary intervention in combination with other treatments such as exercise. Thus, the purpose of this pilot study was to evaluate a modified Paleolithic dietary intervention (MPDI) in the treatment of fatigue and other symptoms in relapsing-remitting MS (RRMS).

METHODS

We measured the effects of a MPDI in 17 individuals with RRMS. Of 34 subjects randomly assigned to control (maintain usual diet) and intervention (MPDI) groups, nine subjects (one man) completed the control group and eight subjects (one man) completed the MPDI.

RESULTS

Significant improvements were seen in Fatigue Severity Scale score and also in Multiple Sclerosis Quality of Life-54 and time to complete (dominant hand) 9-Hole Peg Test from baseline in MPDI subjects compared to controls. Increased vitamin K serum levels were also observed in MPDI subjects postprotocol compared to controls.

CONCLUSION

A Paleolithic diet may be useful in the treatment and management of MS, by reducing perceived fatigue, increasing mental and physical quality of life, increasing exercise capacity, and improving hand and leg function. By increasing vitamin K serum levels, the MPDI may also reduce inflammation.

Self-reported physical activity compared with maximal oxygen uptake in adults

BACKGROUND

Physical activity level and cardiorespiratory fitness are both inversely associated with the risk of cardiovascular diseases and with all-cause mortality. Physical activity questionnaires are often validated against objectively measured maximal oxygen uptake (VO2max).

AIM

To validate a self-report physical activity questionnaire against VO2max and furthermore to establish whether a simple question on self-rated physical fitness could predict objectively measured VO2max.

METHODS

A total of 102 men and women aged between 35 and 65 years were recruited from an ongoing population-based intervention study, the Inter99 Study. Participants reported their self-rated fitness and daily physical activity using a new questionnaire based on metabolic equivalents (MET). VO2max (ml/kg per min) was determined using a graded bicycle test with increasing workload until exhaustion and with simultaneous measurement of breath-to-breath oxygen uptake in 15-s periods. Statistical analyses were performed by linear regression analyses using the self-reported physical activity level as an independent variable and VO2max (l/min) as an dependent variable, and with covariates sex, age and bodyweight.

RESULTS

Data from 53 men and 47 women were analysed. The amount of daily vigorous activity (>6 MET) was significantly positively associated with VO2max (P=0.0001, R=0.76), whereas the total amount of physical activity was not significantly associated with VO2max (P=0.098, R=0.69). A significant trend across three groups of self-rated fitness in relation to VO2max (ml/kg per min) was found (P for trend <0.0001).

CONCLUSION

The physical activity questionnaire has acceptable validity when compared with VO2max in adult men and women. Furthermore, a simple question on self-rated fitness seems to reflect measured VO2max objectively.

Assessing cardiorespiratory capacity in older adults with major depression and Alzheimer disease

ABSTRACT Objective To assess cardiorespiratory capacity through subjective and objective tests in older adults diagnosed with major depression (MDD), Alzheimer disease (AD) and healthy older adults. Methods Fifty seven subjects (72 ± 7.9 years) were divided into three groups: MDD (n = 20), AD (n = 17) and Healthy (n = 20). The subjects answered Hamilton Scale (HAM-D), Mini-Mental State Examination (MMSE), Veterans Specific Activity Questionnaire (VSAQ) and 2-minute Step test. Results MDD and AD showed lower scores than healthy group for Nomogram VSAQ (p < 0.001) and 2-minute Step (p = 0.009; p = 0.008, respectively). Adjusted for age and educational level, no differences among groups were observed for Step (MDD, p = 0.097; AD, p = 0.102). AD group did not present differences to healthy group for Step, when adjusting for MMSE (p = 0.261). Conclusions Despite the lower cardiorespiratory fitness of elderly patients with DM and DA have been found in both evaluations, the results should be viewed with caution, since the tests showed low correlation and different risk classifications of functional loss. In addition, age, level educational and cognitive performance are variables that can influence the performance objective evaluation.

The LIPPSMAck POP (Lung Infection Prevention Post Surgery - Major Abdominal - with Pre-Operative Physiotherapy) trial: study protocol for a multi-centre randomised controlled trial

Background

Post-operative pulmonary complications are a significant problem following open upper abdominal surgery. Preliminary evidence suggests that a single pre-operative physiotherapy education and preparatory lung expansion training session alone may prevent respiratory complications more effectively than supervised post-operative breathing and coughing exercises. However, the evidence is inconclusive due to methodological limitations. No well-designed, adequately powered, randomised controlled trial has investigated the effect of pre-operative education and training on post-operative respiratory complications, hospital length of stay, and health-related quality of life following upper abdominal surgery.

Methods/design

The Lung Infection Prevention Post Surgery - Major Abdominal- with Pre-Operative Physiotherapy (LIPPSMAck POP) trial is a pragmatic, investigator-initiated, bi-national, multi-centre, patient- and assessor-blinded, parallel group, randomised controlled trial, powered for superiority. Four hundred and forty-one patients scheduled for elective open upper abdominal surgery at two Australian and one New Zealand hospital will be randomised using concealed allocation to receive either i) an information booklet or ii) an information booklet, plus one additional pre-operative physiotherapy education and training session. The primary outcome is respiratory complication incidence using standardised diagnostic criteria. Secondary outcomes include hospital length of stay and costs, pneumonia diagnosis, intensive care unit readmission and length of stay, days/h to mobilise >1 min and >10 min, and, at 6 weeks post-surgery, patient reported complications, health-related quality of life, and physical capacity.

Discussion

The LIPPSMAck POP trial is a multi-centre randomised controlled trial powered and designed to investigate whether a single pre-operative physiotherapy session prevents post-operative respiratory complications. This trial standardises post-operative assisted ambulation and physiotherapy, measures many known confounders, and includes a post-discharge follow-up of complication rates, functional capacity, and health-related quality of life. This trial is currently recruiting.

Trial registration

Australian New Zealand Clinical Trials Registry number: ACTRN12613000664741, 19 June 2013.

Validation of a brief step-test protocol for estimation of peak oxygen uptake

BACKGROUND

Physical exercise capacity has been shown to predict cardiovascular disease incidence and is increasingly measured in epidemiological studies. However, direct measurement of peak oxygen uptake is too time consuming in large-scale studies. We therefore investigated whether a brief 3-minute step-test protocol can be used to estimate peak oxygen uptake in these settings.

DESIGN AND METHODS

A group of 97 subjects performed the YMCA step test and a maximal treadmill test with continuous measurement of oxygen uptake. Correlation and linear regression analyses were used to identify VO2peak predictors obtained from the step test and to develop models for VO2peak estimation.

RESULTS

The YMCA model, including the 1-minute heart beat count, predicted VO2peak with R = 0.83. A novel simplified model based on the heart rate at 45 s of recovery performed comparable (R = 0.83). However, models based on heart rate measures were only valid in subjects who completed the test according to protocol, but not in subjects who terminated prematurely. For the applicability in subjects with low exercise capacity, a new model including gas exchange analysis enabled prediction of VO2peak (R = 0.89). All models were validated in an independent sample (r = 0.86-0.91). Exercise time of the step test was less than one-hird of standard ergospirometry (treadmill test: 654 ± 151 s, step test: 180 s, p < 0.001).

CONCLUSION

In large-scale epidemiological studies with limited time slots for exercise testing and significant proportions of subjects with low exercise capacity a modified version of the YMCA step test may be used to predict VO2peak.

The impact of supported telemetric monitoring in people with type 2 diabetes: study protocol for a randomised controlled trial

Background

Diabetes prevalence is increasing and current methods of management are unsustainable. Effective approaches to supporting self-management are required. The aim of this randomized controlled trial is to establish whether supported telemetric monitoring of glycemic control and blood pressure results in reductions in glycosylated hemoglobin (HbA1c; the primary outcome of a measure of long-term glycemic control) and secondary outcomes of blood pressure and weight among people with poorly controlled diabetes compared to a control group receiving usual care.

Methods/Design

Design: multi-center, randomized controlled trial with embedded qualitative study.

Setting: primary care in Lothian, Kent, Glasgow and Borders regions in the UK.

Participants: people with type 2 diabetes and confirmed HbA1c >7.5% (58 mmol/mol).

Intervention/comparison: randomization to intervention or control groups will be performed by the Edinburgh Clinical Trials Unit. Participants in the intervention group will be shown how to use blood glucose and blood pressure monitors and weighing scales which use Bluetooth wireless technology to transmit readings via modem to a remote server. These participants will be asked to provide at least twice weekly measurements of morning and evening blood glucose and weekly measurements of weight and blood pressure. Measurements will be checked at least weekly by practice nurses who will contact the patients to adjust therapy according to guidelines and reinforce lifestyle advice. Participants in the control group will receive usual care. All participants will receive an individual education session.

Follow-up: measurements will be performed at practices 9 months after randomization by research nurses blinded to allocation. The primary outcome measure is HbA1c and secondary outcomes measure are daytime systolic and diastolic blood pressure, weight and cost per quality-adjusted life year.

Analysis: intention-to-treat analyses will be performed. The sample size of 320 participants allows for 20% drop-out and has 80% power at 5% significance to detect a 0.5% absolute (6 mmol/mol) fall in HbA1c in the intervention group. The qualitative study will explore the experiences of patients and professionals using the intervention.

Trial registration

Trial registration number ISRCTN71674628

Telemonitoring based service redesign for the management of uncontrolled hypertension: multicentre randomised controlled trial

OBJECTIVE

To determine if an intervention consisting of telemonitoring and supervision by usual primary care clinicians of home self measured blood pressure and optional patient decision support leads to clinically important reductions in daytime systolic and diastolic ambulatory blood pressure in patients with uncontrolled blood pressure.

DESIGN

Multicentre randomised controlled trial.

SETTING

20 primary care practices in south east Scotland.

PARTICIPANTS

401 people aged 29-95 years with uncontrolled blood pressure (mean daytime ambulatory measurement ≥ 135/85 mm Hg but ≤ 210/135 mm Hg).

INTERVENTION

Self measurement and transmission of blood pressure readings to a secure website for review by the attending nurse or doctor and participant, with optional automated patient decision support by text or email for six months.

MAIN OUTCOME MEASURES

Blinded assessment of mean daytime systolic ambulatory blood pressure six months after randomisation.

RESULTS

200 participants were randomised to the intervention and 201 to usual care; primary outcome data were available for 90% of participants (182 and 177, respectively). The mean difference in daytime systolic ambulatory blood pressure adjusted for baseline and minimisation factors between intervention and usual care was 4.3 mm Hg (95% confidence interval 2.0 to 6.5; P=0.0002) and for daytime diastolic ambulatory blood pressure was 2.3 mm Hg (0.9 to 3.6; P=0.001), with higher values in the usual care group. The intervention was associated with a mean increase of one general practitioner (95% confidence interval 0.5 to 1.6; P=0.0002) and 0.6 (0.1 to 1.0; P=0.01) practice nurse consultations during the course of the study.

CONCLUSIONS

Supported self monitoring by telemonitoring is an effective method for achieving clinically important reductions in blood pressure in patients with uncontrolled hypertension in primary care settings. However, it was associated with increase in use of National Health Service resources. Further research is required to determine if the reduction in blood pressure is maintained in the longer term and if the intervention is cost effective.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN72614272.

Exercise and COPD: therapeutic responses, disease-related outcomes, and activity-promotion strategies

Chronic obstructive pulmonary disease (COPD) reduces patients' exercise capacities and their abilities to perform daily physical activities, thereby increasing morbidity and mortality rates. The cycle of dyspnea, deconditioning, and declining physical activity not only accelerates the progression of COPD but also increases the risk for developing or aggravating metabolic and cardiovascular diseases. Cardiovascular and metabolic comorbidities also limit physical function, and their disabling effects in combination with COPD may be greater than the effects of each disease alone. The impact of COPD and its treatment on the ability to exercise, and the degree of physical activity in daily life, can be measured by field-based tests (eg, the 6-minute walk test or incremental and endurance shuttle-walk test), laboratory-based tests (eg, incremental or constant work-rate treadmill and cycle-ergometer tests), and physical activity assessments (eg, questionnaires and accelerometers). Walking tests increase oxygen consumption and desaturation in patients with COPD more than cycling tests with similar work-rate profiles and may more closely resemble patients' normal activities. Despite the questionable relevance of exercise testing to patients' daily functionality, exercise parameters remain important predictors of survival in patients with COPD. Treatment of COPD (pharmacotherapy, pulmonary rehabilitation, or both) can increase exercise capacity and physical activity in daily life, which potentially slows the decline of lung function, reduces the frequencies of exacerbations and hospitalizations, decreases mortality, slows the progression of comorbidities, improves health-related quality of life, and increases the activity reserve for routine function. This article examines the interactions of reduced physical activity and decreased exercise capacity with the progression of COPD, comorbidities, and mortality. The article also describes the available exercise tests for patients with COPD and reviews the evidence indicating that treating COPD improves exercise capacity. Notably, it appears that even mild COPD reduces exercise capacity and daily physical activity, indicating the need for early intervention.

Effect of oral anabolic steroid on muscle strength and muscle growth in hemodialysis patients

BACKGROUND AND OBJECTIVES

Sarcopenia is common in hemodialysis patients. This study examined whether the anabolic steroid oxymetholone improves muscle mass and handgrip strength in hemodialysis patients and possible mechanisms that might engender such changes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Forty-three eligible hemodialysis patients were randomly assigned to ingest oxymetholone or placebo for 24 weeks. Body composition, handgrip strength, and quality of life were measured during the study. Muscle biopsies were performed and analyzed for mRNA levels for myostatin, IGF-I, IGF binding proteins, and myosin heavy chains and protein expression. Muscle fiber types and diameter were assessed by reduced nicotinamide-adenine dinucleotide staining.

RESULTS

There was a significantly greater increase in fat-free mass and handgrip strength and decrease in fat mass in the oxymetholone compared with the placebo group. Moreover, compared with baseline values, patients given oxymetholone exhibited an increase in fat-free mass, handgrip strength, physical functioning scores, and type I muscle fiber cross-sectional area and a decrease in fat mass, whereas patients receiving placebo did not undergo changes. There was a significantly greater increase in muscle mRNA levels for myosin heavy chain 2×, IGF-I, and IGF-II receptor with oxymetholone treatment than placebo. Liver enzyme rose significantly in the oxymetholone group, but the number of values greater than three times the upper limit of normal were not different between these groups.

CONCLUSIONS

In hemodialysis patients, ingesting oxymetholone was associated with an increase in fat-free mass, handgrip strength, and muscle mRNA levels for several growth factors and a decrease in fat mass, but it also induced liver injury.

Determination of Best Criteria to Determine Final and Initial Speeds within Ramp Exercise Testing Protocols

This study compared strategies to define final and initial speeds for designing ramp protocols. V_O2max was directly assessed in 117 subjects (29 ± 8 yrs) and estimated by three nonexercise models: (1) Veterans Specific Activity Questionnaire (VSAQ); (2) Rating of Perceived Capacity (RPC); (3) Questionnaire of Cardiorespiratory Fitness (CRF). Thirty seven subjects (30 ± 9 yrs) performed three additional tests with initial speeds corresponding to 50% of estimated V_O2max and 50% and 60% of measured V_O2max. Significant differences (P < 0.001) were found between V_O2max measured (41.5 ± 6.6 mL·kg⁻¹·min⁻¹) and estimated by VSAQ (36.6 ± 6.6 mL·kg⁻¹·min⁻¹) and CRF (45.0 ± 5.3 mL·kg⁻¹·min⁻¹), but not RPC (41.3 ± 6.2 mL·kg⁻¹·min⁻¹). The CRF had the highest ICC, the lowest SEE, and better limits of agreement with V_O2max compared to the other instruments. Initial speeds from 50%–60% V_O2max estimated by CRF or measured produced similar V_O2max (40.7 ± 5.9; 40.0 ± 5.6; 40.3 ± 5.5 mL·kg⁻¹·min⁻¹ resp., P = 0.14). The closest relationship to identity line was found in tests beginning at 50% V_O2max estimated by CRF. In conclusion, CRF was the best option to estimate V_O2max and therefore to define the final speed for ramp protocols. The measured V_O2max was independent of initial speeds, but speeds higher than 50% V_O2max produced poorer submaximal relationships between workload and V_O2.

Validity of an exercise test based on habitual gait speed in mobility-limited older adults

OBJECTIVE

To evaluate whether a customized exercise tolerance testing (ETT) protocol based on an individual's habitual gait speed (HGS) on level ground would be a valid mode of exercise testing older adults. Although ETT provides a useful means to risk-stratify adults, age-related declines in gait speed paradoxically limit the utility of standard ETT protocols for evaluating older adults. A customized ETT protocol may be a useful alternative to these standard methods, and this study hypothesized that this alternative approach would be valid.

DESIGN

We performed a cross-sectional analysis of baseline data from a randomized controlled trial of older adults with observed mobility problems. Screening was performed using a treadmill-based ETT protocol customized for each individual's HGS. We determined the content validity by assessing the results of the ETTs, and we evaluated the construct validity of treadmill time in relation to the Physical Activity Scale for the Elderly (PASE) and the Late Life Function and Disability Instrument (LLFDI).

SETTING

Outpatient rehabilitation center.

PARTICIPANTS

Community-dwelling, mobility-limited older adults (N=141).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Cardiac instability, ETT duration, peak heart rate, peak systolic blood pressure, PASE, and LLFDI.

RESULTS

Acute cardiac instability was identified in 4 of the participants who underwent ETT. The remaining participants (n=137, 68% female; mean age, 75.3 y) were included in the subsequent analyses. Mean exercise duration was 9.39 minutes, with no significant differences in durations being observed after evaluating among tertiles by HGS status. Mean peak heart rate and mean peak systolic blood pressure were 126.6 beats/min and 175.0 mmHg, respectively. Within separate multivariate models, ETT duration in each of the 3 gait speed groups was significantly associated (P<.05) with PASE and LLFDI.

CONCLUSIONS

Mobility-limited older adults can complete this customized ETT protocol, allowing for the identification of acute cardiac instability and the achievement of optimal exercise parameters.

Avaliação da capacidade máxima de exercício: uma revisão sobre os protocolos tradicionais e a evolução para modelos individualizados

Os ajustes fisiológicos ao exercício têm sido extensivamente estudados. Apesar do consenso sobre a importância de testes de exercício para a avaliação do consumo máximo de oxigênio (<img border=0 width=32 height=32 id="_x0000_i1065" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2máx), diferenças expressivas entre os protocolos utilizados podem comprometer a comparação de dados e sua utilização clínica ou funcional. A presente revisão analisou os principais protocolos correntemente utilizados na avaliação do <img border=0 width=32 height=32 id="_x0000_i1064" src="../../../../img/revistas/rbme/v17n5/img01.jpg">O2máx, destacando suas vantagens e limitações. Além disso, compararam-se as características de protocolos escalonados em estágios com aquelas de modelos individualizados, conhecidos como protocolos em rampa. Foram revisados 102 estudos publicados entre os anos 1955 e 2009. Os resultados indicaram que, apesar de a maior parte dos estudos apontar vantagens dos protocolos em rampa sobre os mais tradicionais, há uma evidente carência de recomendações sobre diversos aspectos de sua elaboração. São raros os estudos que analisaram a influência de variáveis dos protocolos em rampa sobre os desfechos pretendidos, como o consumo máximo de oxigênio e limiares de transição metabólica. Há dúvidas acerca da melhor maneira de se determinar a capacidade máxima de exercício, velocidade inicial do teste, razão de incremento, interação velocidade/inclinação e tempo de teste. Em suma, os testes em rampa vêm sendo aplicados com base na experiência dos avaliadores, sem que haja realmente um 'protocolo' que norteie a sua montagem. Estudos que possam contribuir para o desenvolvimento de critérios mais formais e precisos para a elaboração de protocolos em rampa, portanto, fazem-se necessários.

The role of NT-proBNP in explaining the variance in anaerobic threshold and VE/VCO(2) slope

PURPOSE

We investigated whether anaerobic threshold (AT) and ventilatory efficiency (minute ventilation/carbon dioxide production slope, VE/VCO2 slope), both significantly associated with mortality, can be predicted by questionnaire scores and/or other laboratory measurements.

METHODS

Anaerobic threshold and VE/VCO(2) slope, plasma N-terminal pro-brain natriuretic peptide (NT-proBNP), and the echocardiographic markers left ventricular ejection fraction (LVEF) and left atrial (LA) diameter were measured in 62 patients with heart failure (HF), who also completed the Minnesota Living with Heart Failure Questionnaire (MLHF), and the Specific Activity Questionnaire (SAQ). Linear regression models, adjusting for age and gender, were fitted.

RESULTS

While the etiology of HF, SAQ score, MLHF score, LVEF, LA diameter, and logNT-proBNP were each significantly predictive of both AT and VE/VCO2 slope on stepwise multiple linear regression, only SAQ score (P < .001) and logNT-proBNP (P = .001) were significantly predictive of AT, explaining 56% of the variability (adjusted R(2) = 0.525), while logNT-proBNP (P < .001) and etiology of HF (P = .003) were significantly predictive of VE/VCO(2) slope, explaining 49% of the variability (adjusted R(2) = 0.45). The area under the ROC curve for NT-proBNP to identify patients with a VE/VCO(2) slope greater than 34 and AT less than 11 mL · kg(-1) · min(-1) was 0.797; P < .001 and 0.712; P = .044, respectively. A plasma concentration greater than 429.5 pg/mL (sensitivity: 78%; specificity: 70%) and greater than 674.5 pg/mL (sensitivity: 77.8%; specificity: 65%) identified a VE/VCO(2) slope greater than 34 and AT lower than 11 mL · kg(-1) · min(-1), respectively.

CONCLUSIONS

NT-proBNP is independently related to both AT and VE/VCO(2) slope. Specific Activity Questionnaire score is independently related only to AT and the etiology of HF only to VE/VCO(2) slope.

Calculated metabolic equivalents: a tool for exercise prescription among African American women

BACKGROUND

Average daily steps (ADS) are a low-technology measurement of activity that is useful for exercise prescription. However, research demonstrates poor validity for ADS as a measure of exercise capability. We present a superior low-technology measure of exercise capability, which is easily applied by practitioners in clinical or nonclinical settings.

METHODS

Based on analysis of baseline data from an intervention study to test a sustainable approach to long-term physical activity improvement for employed African American women, between 2005 and 2008, we examined exercise tolerance metabolic equivalents (METs) and ADS of 158 participants and generated an alternative measure of exercise capacity. We conducted regression analysis to determine the impact of key health indicators on exercise capacity and examined associations between our predictive model and true (MET) exercise performance.

RESULTS

Using our predictive equation, 79.33% of participants were correctly categorized (very high, high, medium) based on our tool, with 10 women (6.67%) mischaracterized by one level higher than actual MET achievement and 21(14.00%) mischaracterized as one category lower than actual MET achievement. In contrast, using ADS alone resulted in 22.15% correctly categorized participants.

CONCLUSIONS

The proposed tool is superior to existing low-technology measures of exercise capacity while retaining strong utility in nonclinical and low-resource settings.

Comparative value of NYHA functional class and quality-of-life questionnaire scores in assessing heart failure

PURPOSE

To assess the relationships between New York Heart Association (NYHA) functional class, quality of life, aerobic capacity (peak oxygen uptake, (.)VO2), ventilatory efficiency (minute ventilation/carbon dioxide production slope, VE/(.)VCO2 slope), and brain natriuretic peptide (BNP) in creating a model for predicting peak (.)VO2).

METHODS

Cardiopulmonary exercise testing was performed in 62 patients. A baseline blood sample was taken to measure the N-terminal prohormone BNP (NT-proBNP). Patients also completed the Minnesota Living with Heart Failure Questionnaire (MLHF) and the Specific Activity Questionnaire (SAQ), and NYHA functional class was determined.

RESULTS

NYHA functional class correlated more strongly with SAQ score than with MLHF score. Peak (.)VO2 and VE/(.)VCO2 slope had stronger associations with NYHA functional class and SAQ score than with MLHF score. NT-proBNP plasma levels correlated more significantly with NYHA functional class and SAQ score (both P < .001) than with MLHF score. Using multiple linear regression analysis adjusted for age and sex, SAQ score, NT-proBNP, and etiology of heart failure had significant independent relationships with peak (.)VO2, explaining 63% of its variability (adjusted R(2) = 0.596).

CONCLUSIONS

Cardiopulmonary exercise variables and plasma NT-proBNP are associated more with NYHA functional class and SAQ score than with MLHF score. When combined, SAQ score, NT-proBNP, and etiology of heart failure can satisfactorily predict peak oxygen uptake.

Cultural adaptation of an instrument to assess physical fitness in cardiac patients

OBJECTIVE

To validate the content and to evaluate the reliability of the Veterans Specific Activity Questionnaire instrument, culturally adapted for use in the Brazilian population of cardiac patients.

METHODS

The instrument was translated and back-translated and subsequently analyzed by a committee of judges to evaluate its semantic-idiomatic and cultural equivalences. Physical activities were replaced when indicated in the instrument, but uncommon in the daily life of the target population. Another committee of specialists analyzed the metabolic equivalence of replaced activities. The proportion of agreement of evaluation of the judges was quantified by the Content Validity Index. The pre-test was performed in two stages (n1 and n2=15). Reliability was assessed using the test-retest (interval of 7-15 days, n = 50).

RESULTS

In the evaluation of semantic-idiomatic and cultural equivalences, items with a Content Validity Index < 1 were reviewed until consensus among the judges was obtained. The second committee found 100% of agreement in the analysis of metabolic equivalence between original and replaced activities. Test-retest analysis indicated a Kappa coefficient of agreement (k = 0.86; (p<0.001), suggesting temporal stability of the instrument.

CONCLUSIONS

The Brazilian version of the Veterans Specific Activity Questionnaire showed evidence of reliability, according to the temporal stability criterion and adequate cultural content.