Effects of Exercise Training versus Attention on Plasma B-type Natriuretic Peptide, 6-Minute Walk Test and Quality of Life in Individuals with Heart Failure

Purpose

The purpose of this study was to compare an Exercise Training Group (EX) with an Attention-Control Group (AT-C) to more specifically assess the impact of exercise training on individuals with heart failure (HF).

Methods

Forty-two individuals with HF were randomized to AT-C or EX that met with the same frequency and format of investigator interaction. Baseline, 12- and 24-week measurements of B-type naturetic peptide (BNP), 6-minute walk test (6-MWT), and the Kansas City Cardiomyopathy Questionnaire (KCCQ) were obtained.

Results

BNP tended to increase in the AT-C while remaining stable in the EX over time. A clinically significant increase in 6-MWT was demonstrated by the EX but not the AT-C. The EX achieved a clinically significant change on the KCCQ at 12 weeks, with further improvement by 24 weeks, while the AT-C demonstrated a clinically significant change at 24 weeks.

Conclusions

Attention alone was inadequate to positively impact BNP levels or 6-MWT distances, but did have a positive impact on quality of life after 24 weeks. Although exercise offers enhanced benefits, individuals with HF unable to participate in an exercise program may still gain quality of life benefits from participation in a peer-support group that discusses topics pertinent to HF.Key Words: heart failure, attention, exercise     

IGF1–PI3K-induced physiological cardiac hypertrophy: Implications for new heart failure therapies,biomarkers, and predicting cardiotoxicity

Heart failure represents the end point of a variety of cardiovascular diseases. It is a growing health burden and a leading cause of death worldwide. To date, limited treatment options exist for the treatment of heart failure, but exercise has been well-established as one of the few safe and effective interventions, leading to improved outcomes in patients. However, a lack of patient adherence remains a significant barrier in the implementation of exercise-based therapy for the treatment of heart failure. The insulin-like growth factor 1 (IGF1)–phosphoinositide 3-kinase (PI3K) pathway has been recognized as perhaps the most critical pathway for mediating exercised-induced heart growth and protection. Here, we discuss how modulating activity of the IGF1–PI3K pathway may be a valuable approach for the development of therapies that mimic the protective effects of exercise on the heart. We outline some of the promising approaches being investigated that utilize PI3K-based therapy for the treatment of heart failure. We discuss the implications for cardiac pathology and cardiotoxicity that arise in a setting of reduced PI3K activity. Finally, we discuss the use of animal models of cardiac health and disease, and genetic mice with increased or decreased cardiac PI3K activity for the discovery of novel drug targets and biomarkers of cardiovascular disease.     

IGF1–PI3K-induced physiological cardiac hypertrophy: Implications for new heart failure therapies,biomarkers, and predicting cardiotoxicity

Heart failure represents the end point of a variety of cardiovascular diseases. It is a growing health burden and a leading cause of death worldwide. To date, limited treatment options exist for the treatment of heart failure, but exercise has been well-established as one of the few safe and effective interventions, leading to improved outcomes in patients. However, a lack of patient adherence remains a significant barrier in the implementation of exercise-based therapy for the treatment of heart failure. The insulin-like growth factor 1 (IGF1)–phosphoinositide 3-kinase (PI3K) pathway has been recognized as perhaps the most critical pathway for mediating exercised-induced heart growth and protection. Here, we discuss how modulating activity of the IGF1–PI3K pathway may be a valuable approach for the development of therapies that mimic the protective effects of exercise on the heart. We outline some of the promising approaches being investigated that utilize PI3K-based therapy for the treatment of heart failure. We discuss the implications for cardiac pathology and cardiotoxicity that arise in a setting of reduced PI3K activity. Finally, we discuss the use of animal models of cardiac health and disease, and genetic mice with increased or decreased cardiac PI3K activity for the discovery of novel drug targets and biomarkers of cardiovascular disease.     

Program Description: Physical Therapy in a Heart Failure Clinic

Aerobic exercise and resistance training have been proven to be beneficial for patients with heart failure. Current reimbursement guidelines exclude these patients from our traditional cardiac rehabilitation program, so at Newton Wellesley Hospital a clinic model was developed for the disease management and exercise of heart failure patients.Key Words: heart failure, physical therapy, exercise     

Outcomes of an Education and Exercise Program for Adults with Type 2 Diabetes,and Comorbidities that Limit their Mobility: A Preliminary Project Report

Purpose: Some adults with type 2 diabetes mellitus (T2DM) have comorbidities and mobility impairments that limit their exercise capacity. In consideration of this, we developed and piloted a program called Active Steps for Diabetes for people with T2DM, comorbidities, and mobility impairments. The purpose of this paper was to report outcomes for the pilot program. Methods: Active Steps for Diabetes, an 8-week program, included instruction on diabetes self-care andgroup and home exercise programs. Twenty-two females (62.7 ± 6.1yrs) with T2DM and self-reported mobility impairments completed the program. Six participants used a walking aid. Outcome measures included two risk factors for coronary artery disease [daily physical activity and body mass index (BMI)], cardiovascular fitness (6-minute walk distance), and knowledge of diabetes-specific exercise guidelines. A two-way repeated measures ANOVA was used to compare outcomes before and after the program and between participants who did and did not use a walking aid. Results: Active Steps for Diabetes was effective in increasing daily physical activity in both groups of subjects (walking aid group: 2.6 days/week [95% confidence interval (CI) = 2.1 to 3.3]; no walking aid group: 1.9 days/week [95% CI=1.2 to 2.5]). This was accompanied by increases in 6-minute walk distances (walking aid group: 54.0 m [95% CI = 36.4 to 71.6]; no walking aid group: 62.6 m [95% CI=55.7 to 69.4]). Changes in BMI were not significant (walking aid group: −0.4 [95% CI = −1.2 to 0.4]; no walking aid group: −.24[95% CI = −.91 to .44]). Increases in knowledge of diabetes-specific exercise guidelines were observed in both groups (walking aid group: 18.8% [95% CI = 11.3 to 26.4]; no walking aid group: 19.3% [95% CI = 16.1 to 22.5]). Discussion:: Physical inactivity and low cardiovascular fitness are predictors of CAD morbidity and mortality in adults with T2DM. This pilot program suggests that a model for diabetes education, incorporating exercise programs developed by a physical therapist, may increase physical activity, improve endurance, and thereby potentially reduce CAD risk in people with T2DM and mobility impairments from comorbidities.Key Words: type 2 diabetes, physical activity     

自行车运动员进行功率自行车3种递增负荷运动实验比较有氧耐力研究

目的:通过40名自行车专业运动员在功率自行车上进行3种递增负荷运动实验比较有氧耐力.方法:40名自行车运动员(男21,女19)在功率自行车上进行有氧力竭运动,分别采用3 min递增法、1 min递增法和线性递增法进行运动负荷递增,用Oxyam Pro运动心肺功能仪观察最大耗氧量(VO2max)、心率(HRmax)、呼吸商(RQ)等指标,运动前、后采集血乳酸(Lac).结果:3种递增负荷运动实验的VO2max、HRmax指标无显著性差异(P>0.05),3种实验的RQ、Lac指标差异无显著规律性.结论:自行车运动员进行功率自行车3种递增负荷运动实验比较有氧耐力没有统计学差异,3种递增负荷运动实验均可作为功率自行车进行有氧耐力测试的方法.     

少年运动员恒定负荷条件下血浆降钙素基因相关肽的变化

采用放射免疫法对 2 0名少年运动员 ,在 1 0 0W恒定负荷运动条件下的血浆降钙素基因相关肽 (CGRP)含量进行了测定。结果表明 :血浆CGRP含量在运动 30分钟后即刻较安静时上升 1 9% (P <0 .0 5) ;与对照组相比无显著差异 (P >0 .0 5)。结合有关心功能指标提示 :中等强度的耐力运动可使血浆CGRP含量显著增加     

Examination of the Six Minute Walk Test to Determine Functional Capacity in People with Chronic Heart Failure: A Systematic Review

Purpose: To evaluate the reliability and validity of the six-minute walk test (6MWT) with respect to its ability to predict functional capacity in patients with chronic heart failure. Methods: A systematic review was performed via 8 databases to assess relevant English language full-text articles published from January 1, 1980 to October 31, 2009. Participant characteristics, interventions, reliability, validity, and predictive value for each article with respect to functional capacity as defined by peak VO₂ levels were extracted and compared. Quality Assessment of Diagnostic Accuracy Studies (QUADAS) scores were determined for each study. Results: Fourteen studies met the selection criteria. Comparison of the studies investigating reliability shows that the 6MWT has good reproducibility. The 6MWT demonstrates moderate correlation with peak VO₂ levels, and ability to predict VO₂ (functional capacity) dependent on distance walked. Cut-off distances vary from 300 to 490 meters depending on the study; if total distance walked remains equal or less than these values, the 6MWT retains its strong predictive value. Conclusion: The 6MWT has good reliability, moderate validity, and a significant ability to predict functional capacity in patients with CHF who do not walk greater than 490 meters.Key Words: six-minute walk test, chronic heart failure, functional capacity, peak VO₂     

运动对慢性心力衰竭大鼠心脏交感神经功能的调节——去甲肾上腺素转运蛋白的作用

目的:探讨去甲肾上腺素转运蛋白(NET)在运动改善慢性心力衰竭大鼠心脏交感神经功能、心功能和运动耐力中的作用。方法:结扎大鼠冠状动脉建立心梗后心衰模型。大鼠休息4周后随机分为假手术安静组(Sham)、假手术运动组(Sham+E)、心梗安静组(MI)和心梗运动组(MI+E),Sham+E组和MI+E组进行为期10周的跑台运动,Sham组和MI组保持安静状态。实验结束后,利用递增负荷运动实验测定大鼠力竭时间;超声心动图检测左心室收缩末内径(LVESD)、左心室舒张末内径(LVEDD)、心率(HR)、缩短分数(FS)和左室射血分数(LVEF);Masson染色进行心脏组织病理学观察;测定心肌和血浆去甲肾上腺素(NE)水平;实时荧光定量PCR检测交感神经节和心肌NET mRNA水平;Western blot法检测心肌NET蛋白表达。结果:术后14周,与Sham组比较,Sham+E组HW/BW、LVEF增加,HR降低,力竭时间延长,MI组心脏重量(HW)、心脏重量/体重(HW/BW)、LVESD和LVEDD增加,FS和LVEF降低,血浆和心肌NE水平升高,心脏交感神经节NET mRNA降低,心肌NET蛋白水平降低,力竭时间减少。与MI组比较,MI+E组体重(BW)下降,HW和HW/BW增加,LVESD和LVEDD稍有降低,FS和LVEF无显著性变化,血浆和心肌NE水平降低,心脏交感神经节NET mRNA升高,心肌NET蛋白水平升高,力竭时间延长(其中,NE、NET mRNA和蛋白水平在MI+E组与Sham组无显著性差异)。结论:长期有氧运动通过上调心脏交感神经元NET表达,减少并恢复了交感神经末梢NE释放量,从而改善了心衰后交感神经系统过度兴奋状态并提高运动耐力。     

Physiological Changes in Middle-Aged Men following a Ten-Week Jogging Program

Abstract

Twenty-one middle-aged males who participated in a jogging program performed a 6-minute submaximal exercise bout on a bicycle ergometer to determine if any differences existed between the results of heart rate and blood pressure tests taken before and after 10 weeks of training. Heart rates were obtained from electrocardiograph tracings and blood pressures were measured by a manual sphygmomanometer. The t test for differences between the means of related measures of heart rates and blood pressures was used with the .01 level selected for significance. Differences between the means of pre-and post tests of heart rate, under pre-exercise, submaximal exercise, and postexercise conditions, were all statistically significant. The jogging program did not produce any significant change in either systolic or disastolic blood pressure. It was concluded that 10 weeks of participation in a systematic jogging program will produce reductions in heart rates for middle-aged men at rest, during submaximal exercise, and during the recovery period following exercise.     

Akute und chronische Effekte von Ausdauerbelastungen auf das Herz bei Sportlern, gesunden Normalpersonen und Patienten

Due to endurance exercise-induced increases of the cardiac biomarkers troponin and B-type natriuretic peptide (BNP), which are usually elevated in patients with acute myocardial infarction and heart failure and used in clinical practice as diagnostic tools in these diseases, the clinical and sportsmedical relevance of these exercise-induced increases was unclear. Therefore, the aim was to examine this topic systematically by consecutive studies. Considering the acute effects of endurance exercise, an intensity- and duration-dependent short-term elevation could be demonstrated in the majority of healthy athletes without pathological relevance. Considering the chronic effects of endurance exercise it could be shown that regular and competitive endurance exercise training induces an athlete??s heart with harmonic eccentric hypertrophy of the left and right ventricle, which also is not of pathological relevance. In conclusion it can be assumed from the results of these studies that acute and chronic endurance exercise is not harmful for the healthy heart.     

The Effects of a Twelve-Week Home Walking Program on Cardiovascular Parameters and Fatigue Perception of Individuals with Multiple Sclerosis: A Pilot Study

Purpose: To investigate the effects of a 12-week home walking program on cardiovascular parameters, fatigue perception, and walking distance in persons with multiple sclerosis (MS). Methods: Twelve ambulatory persons with MS, not currently participating in exercise were randomly assigned to control (C) or experimental groups (EX). Pretest data collection included resting HR, BP, fatigue perception (Fatigue Severity Scale), and 6-minute walk test. EX received a home walking program (30 min, 3 × week, × 12 weeks), using a modification of Karvonen''s formula to calculate HR range. A HR monitor was used to adjust walking speed. The C group refrained from any regular exercise. Posttest data were collected at week 12 and analyzed using the Mann-Whitney U Test. Results: No statistically significant differences were noted between groups in any measured parameters; however, walking distance and Physiologic Cost Index did improve in the exercise group. Conclusion: No adverse events or increase in fatigue levels related to the exercise intervention were reported in this study. This home walking program may not be of sufficient intensity to elicit significant cardiovascular changes. Abnormal cardiac responses have been documented in this population, which may have affected the results. Clinicians may need to use alternate measures to assess fitness in this population.Key Words: multiple sclerosis, home walking program, cardiovascular, aerobic     

Circuit Training Time Allotments in a Typical Physical Education Class Period

Abstract

As an attempt in determining the relative effectiveness of three time allotments to circuit training and active games in a typical physical education class period, treatment groups were assigned either a 5- and 25-minute, a 10- and 20-minute, or a 15- and 15-minute distribution of time. Pre- and post-measures were taken on six circuit exercises: leg-exchanges, squat-thrusts, sit-ups, bench-steps, push-ups, and pull-ups. Significant improvement was observed for all three groups on all exercise. The 15-minute allotment to circuit training resulted in significantly better performances on sit-ups and leg-exchanges than the 5-minute allotment, but in lower performance on bench-steps when compared to the 10-minute allotment.     

振荡调整手法对青少年运动员腰椎小关节紊乱的疗效观察

目的：观察振荡调整手法对青少年运动员腰椎小关节紊乱的影响。方法：96例诊断为“腰椎小关节紊乱”的青少年运动员随机分为手法组49例、对照组47例。手法组以松解手法配合振荡调整手法治疗,对照组以超短波电疗治疗,手法组每次10 min,对照组每次30 min,两组均每周治疗5次,测定全部受试者在治疗前、治疗2次、治疗3次、治疗5次,4个时间点的视觉模拟量表（VAS评分）、腰腹部肌张力值变化。结果：手法组治疗3次后VAS评分优于对照组,手法组治疗5次后,双侧竖脊肌及患侧腋中线/髂嵴与肋弓连线中点的肌张力值改善程度优于对照组;对侧腋中线/髂嵴与肋弓连线中点肌张力的改善程度无显著差异。结论：振荡调整手法能有效缓解青少年运动员腰椎小关节紊乱症状。     

β-受体阻断剂对心脏康复跑台运动时机能、生理、临床和感觉反应的影响

目的：测试服用和未服用β-受体阻断剂的心梗后患者（PMIP）在跑台运动中其功能、生理、临床及自我感觉方面的反应。方法：46名服用β-受体阻断剂的男性PMIP和55名未服用β-受体阻断剂的男性PMIP进行递增负荷运动实验，其间记录每级负荷时的摄氧量（VO2）、心率（HR）、血压和自我用力感觉（RPE），并持续监测12导联心电图（ECG）。结果：服用β-受体阻断荆的患者其安静时和运动中的HR、最大心率百分比（％HRmax）及心率血压乘积（RPP）显著低于未服用β-受体阻断剂的患者（P〈0．01）。运动中，服用β-受体阻断剂的患者有59％能够完成改良布鲁斯跑台方案的第Ⅳ级运动，而在未服用β-受体阻断剂的患者中仅有49％能完成这一负荷。两组在运动中各级别VO2、RPE及ST段下移无显著性差异。结论：由β受体阻断剂所致的HR降低并没有直接地影响到氧利用和代谢机能。     

Cross-Validation of a Quarter-Mile Walk Test Using Two VO2 max Regression Models

This study was conducted to evaluate the accuracy of 2 regression models (Dolgener, Hensley, Marsh, & Fjelstul, 1994; Kline et al., 1987) in the prediction of VO_{2 max} College-age men and women (N = 37) performed, in a counter-balanced order, a 1/4-mile walk test, a 1-mile walk test, followed by a maximal graded exercise test. For both walking tests, participants were instructed to self-select a fast (but less than maximal) steady exercise pace. For the 1-mile walk, the applicable data (e.g., age, gender, body weight, elapsed 1-mile exercise time, and ending exercise heart rate) were inserted into the Dolgener et al. (1994) equation and Kline et al. equation, respectively, to predict VO_{2 max} A similar approach was taken to predict VO_{2 max} for the 1/4-mile walk, except that elapsed exercise times were first multiplied by 4 to get 1-mile walk equivalents (because both equations are designed to predict VO_{2 max} based on 1-mile data). The Kline et al. equation provided relatively accurate estimates of observed VO_{2 max} values with mean residuals ranging from -0.36 to + 1.59 ml kg^-1; min-1 and correlations ranging from .81 to .84. The percentage of predicted and observed VO_{2 max} values within 4.5 ml kg^-1; min^-1; ranged from 67.6% to 75.7%. The Dolgener et al. (1994) equation, on the other hand, underpredicted observed VO_{2 max} values with mean residuals ranging from -5.67 to -6.83 ml kg^-11; min^-1; and correlations ranging from .84 to .85. The percentage of predicted and observed VO_{2 max} values within 4.5 ml kg^-1; min^-1; ranged from 18.9% to 43.2%. The results of this study provide evidence that the 1/4-mile walk predicts VO_{2 max} with about the same accuracy as the 1-mile walk.     

Home IV Antibiotic Therapy and Exercise Capacity in Children with CF: A Case Series

Purpose: This case series describes the effect of home intravenous (IV) antibiotic therapy on spirometry and exercise capacity in a group of children with cystic fibrosis (CF). Methods: Outcomes from 10 children with CF who were prescribed a 14-day course of home IV antibiotics for a respiratory exacerbation are reported. All children performed spirometry and a modified shuttle test (MST) before and after 14-days of home IV therapy. Results: After 14 days, FEV₁ increased by mean (± SE) 12 ± 4 % (p < 0.05) but mean MST did not improve compared to baseline. All children improved or maintained spirometry values with treatment, however, only 5 improved MST distance. Conclusion: After 14 days of home IV antibiotic therapy, a significant improvement in spirometry, but not exercise capacity, was seen in this small series of children with CF. The lack of improvement in exercise capacity for all children following home IV antibiotic therapy suggests factors other than spirometry determine exercise capacity. Identifying and investigating the factors that influence exercise capacity during home IV antibiotic therapy requires further investigation.Key Words: cystic fibrosis, home IV therapy, FEV₁, Modified Shuttle Test     

青少年学生单纯性超重与肥胖的综合干预方法研究

运用综合干预实验等方法,研究单纯性超重与肥胖青少年学生减肥前、中、后形态、机能、生理、生化指标、运动功能等变化。结果表明,干预实验后的青少年学生各项指标均有明显改善,与干预前比较有显著性差异(P<0.05)。实验证明,有氧运动+医学营养+心理矫正+医务监督,可有效降低青少年学生单纯性超重和肥胖。