Rehabilitation of decreased motor performance in patients with chronic fatigue syndrome: should we treat low effort capacity or reduced effort tolerance?

Aim: The aetiology, pathophysiology, diagnostic delineation and treatment of chronic fatigue syndrome (CFS) remain a matter of debate. Here some aspects of the debate are elucidated, with a particular focus on the patients' decreased motor performance.

Hypothesis: The pathophysiological basis of decreased motor performance in CFS may, theoretically, involve three components: (1) a peripheral energetic deficit (impaired oxidative metabolism and/or physical deconditioning); (2) a central perceptual disturbance (higher effort sense or increased 'interoception'); and (3) a fundamental failure of the neurobiological stress system, leading to an abnormal 'sickness response'.

Effects of post-absorptive and postprandial exercise on glucoregulation in metabolic syndrome.

Objective: The aim of this study was to investigate the effects of an acute exercise bout in the morning in the post-absorptive or postprandial state on the glycemic and insulinemic response to three standardized meals throughout the day. It is hypothesized that post-absorptive exercise enhances fat oxidation rate during exercise and thereafter attenuates the glucose and insulin response to subsequent meals.

Research Methods And Procedures: Seven sedentary males with metabolic syndrome (age, 45 +/- 11 years; BMI, 34 +/- 3 kg/m2) were studied in a crossover design comparing three conditions: no exercise, postprandial and post-absorptive exercise (at approximately 60% of the individual VO2max for 45 minutes).

How relevant are exercise capacity measures for evaluating treatment effects in chronic fatigue syndrome? Results from a prospective, multidisciplinary outcome study.

Objective: To evaluate the outcome of a multidisciplinary treatment programme for patients with chronic fatigue syndrome, including health-related quality of life (HRQoL) and psychosocial variables, and exercise capacity measures.

Design: A six-month prospective outcome study.

Setting: University outpatient rehabilitation clinic; group setting.

Exercise programs for older men: mode and intensity to induce the highest possible health-related benefits.

Background: Although health-related benefits of fitness training in older men are well established, it is not clear yet which mode and intensity of a exercise program is most effective. This study addresses whether the combination of endurance (ED) and resistance training in older men have supplementary health-related benefits in addition to profits attained through endurance training alone. Additionally, effects of moderate- and low-intensity resistance training are compared.

The pulse pressure-to-stroke index ratio predicts cardiovascular events and death in uncomplicated hypertension.

Objectives: The goal of this study was to assess the prognostic power of the pulse pressure-to-stroke index (PP-to-SVi) ratio for cardiovascular events and mortality in patients with uncomplicated hypertension.

Background: The prognostic significance of pulse pressure (PP) has been studied repeatedly, but few data are available on the PP-to-SVi ratio.

Methods: Invasive hemodynamic measurements, including brachial intra-arterial pressure and stroke index by the direct oxygen Fick method, were performed in the period 1972 to 1982 in 192 patients with uncomplicated hypertension; their outcome was ascertained in 1994.

Left ventricular diastolic function predicts outcome in uncomplicated hypertension.

Whereas left ventricular systolic function has been shown to predict outcome in hypertensive patients without clinical evidence of heart failure, the prognostic power of diastolic function has not been examined. We assessed the relation of mean pulmonary capillary wedge pressure as an index of left ventricular diastolic function to mortality and the incidence of cardiovascular events in patients with uncomplicated hypertension at baseline. Invasive hemodynamic measurements were performed in the period 1972 to 1982 in 172 hypertensive patients without evidence of cardiovascular disease, cardiomegaly or heart failure, and their outcome was ascertained in 1994.

A randomised, placebo-controlled, double-blind, crossover study of losartan and enalapril in patients with essential hypertension.

The primary objective of this randomised, placebo- controlled, double-blind, crossover study, was to evaluate and compare the longer term effects of the angiotensin II type 1 receptor antagonist losartan and the converting enzyme inhibitor enalapril on 24-h ambulatory blood pressure (BP). After a 4-week placebo run-in period, nine patients with essential hypertension entered the double-blind phase of the study, which consisted of three 6-week periods during which patients were treated with placebo, enalapril 20 mg o.d.

Relationships of heart rate and heart rate variability with conventional and ambulatory blood pressure in the population.

Background: Most studies on relationships between blood pressure and autonomic nervous function, assessed by power spectral analysis of heart rate variability, have used conventional or clinic blood pressure measurements in selected subjects, which may have influenced the results.

Objective: We aimed to investigate, in a population-based approach, associations of heart rate and heart rate variability, assessed in basal resting conditions and in response to standing, with conventional blood pressure measured by an investigator, and with ambulatory blood pressure monitored outside the laboratory.

Methods: RR interval and respiration were registered in 614 men and women, ages 25-89 years.

Peak oxygen uptake better predicts outcome than submaximal respiratory data in heart transplant candidates.

Background: Many studies have focused on the prognostic power of peak oxygen uptake VO(2) in patients with chronic heart failure, but maximal exercise testing is not without risk. The purpose of the present study was, therefore, to assess the prognostic significance of the steepness of changes in ventilation and carbon dioxide output VO(2) during submaximal exercise in comparison with VO(2).

Methods And Results: The study population consisted of 284 adult heart transplant candidates who performed a graded maximal bicycle ergometer test with respiratory gas analysis.

Prognostic significance of exercise versus resting blood pressure in patients with chronic heart failure.

Background: Results on the prognostic value of exercise blood pressure differ among studies; this may be related to the characteristics of the studied population.

Objective: To assess the prognostic significance of blood pressure measured during exercise in patients with chronic heart failure being considered for heart transplantation.

Design And Methods: Symptom-limited bicycle exercise testing with measurement of blood pressure and respiratory gas analysis was performed in 274 potential candidates for heart transplantation.

Prediction of peak exercise oxygen uptake by cardiopulmonary measurements at rest in heart transplant candidates.

Objective: Peak oxygen uptake (VO2) is a powerful prognostic index, but maximal exercise testing in heart transplant candidates has a number of disadvantages. It is unknown whether it is possible to predict peak VO2 from a comprehensive dataset with parameters of heart and lung function at rest.

Methods: One hundred adult patients in sinus rhythm and with either idiopathic or ischaemic heart failure performed a graded cycle ergometer test until volitional fatigue and underwent radionuclide ventriculography, heart catheterization, and lung function measurements at rest.

Influence of demographic, anthropometric and lifestyle characteristics on heart rate and its variability in the population.

Objective: The purpose of this investigation was to assess the effects of age, gender, posture and their interactions, and of body mass index and lifestyle factors, on heart rate, its total variance and its variability in the frequency domain in a population-based sample of healthy subjects.

Methods: RR interval and respiration were registered in the supine and in the standing position in 302 men and 312 women, aged 25-89 years; 424 subjects were healthy and had recordings suitable for analysis. Power spectral analysis was performed by use of autoregressive modelling and by fast Fourier transform, and the low-frequency (LF) and high-frequency (HF) components were expressed in both absolute (ms2) and normalized units

Results: In the supine position, heart rate was higher in women than in men (P<0.

Power spectral analysis of heart rate variability by autoregressive modelling and fast Fourier transform: a comparative study.

Objective: To compare the results from autoregressive modelling (ARM) and from fast Fourier transform (FFT), the most commonly used methods for the analysis of short-term heart rate variability in the frequency domain.

Methods & Results: RR interval and respiratory activity were recorded in the supine and standing positions under standardized laboratory conditions in a population-based sample of 614 subjects. The low-(LF) and high-frequency (HF) components of heart rate variability were identified by power spectral analysis, by use of FFT, with application of two sets of frequency ranges, and by ARM; LF and HF power were expressed in both normalized (%) and absolute units (ms2).

Atrial fibrillation is associated with a lower exercise capacity in male chronic heart failure patients.

Objective: To study the influence of atrial fibrillation on peak oxygen uptake (peak VO2) in chronic heart failure. An unfavourable effect of atrial fibrillation has been shown in several patient populations, but the results have not been consistent in chronic heart failure.

Methods: Data were analysed from male heart transplant candidates who were able to perform graded bicycle ergometry until exhaustion with respiratory gas analysis and measurement of heart rate.

Impact of age and gender on peak oxygen uptake in chronic heart failure.

Anthropometric and demographic characteristics are important determinants of exercise performance in healthy subjects, but their influence has not yet been studied in severe chronic heart failure, although peak oxygen uptake is frequently assessed in such patients for prognostic purposes. The aim of the present analysis was to examine the association between peak oxygen uptake and age, gender, and measures of body size in patients with severe chronic heart failure. We selected 122 (99 male) adult heart transplant candidates who were able to perform a bicycle ergometer test with respiratory gas analysis until voluntary fatigue.

Life style as a blood pressure determinant.

In Belgium, an affluent Western European country, participation in sports, alcohol intake, and living in a working class area were identified as the life style factors with the closest associations with the blood pressure level. Obesity was another important blood pressure correlate. Sodium intake, determined from the 24 h urinary output, and smoking were not associated with blood pressure.

Prognostic significance of peak oxygen uptake in hypertension.

The aim of this study was to investigate the prognostic value of cardiopulmonary fitness in hypertension. From 1972 to 1982 oxygen uptake and heart rate were recorded during an exercise test to exhaustion in 216 patients (143 men). Their outcome was ascertained in 1994.

Prognostic value of invasive hemodynamic measurements at rest and during exercise in hypertensive men.

In 1994, we ascertained the outcome of 143 hypertensive men in whom invasive hemodynamic measurements were performed at rest and during graded bicycle exercise during the period 1972-1982 to assess (1) which of the hemodynamic components of blood pressure is associated with the incidence of cardiovascular events and total mortality, and (2) whether the hemodynamic response to dynamic exercise adds prognostic precision to the data at rest. During 2186 patient years of follow-up, 38 patients suffered at least one fatal or nonfatal cardiovascular event and 17 patients died. Cox regression analysis showed that systolic pressure and systemic vascular resistance measured at rest, during submaximal exercise (50 W), and at peak effort were significant (P < .