We determined the physiological effects of exercise training on exercise capacity and quadriceps muscle function in patients with idiopathic pulmonary arterial hypertension (iPAH).In total, 19 clinically stable iPAH patients (New York Heart Association II-III) underwent a supervised exercise training programme for the duration of 12 weeks. Maximal capacity, endurance capacity and quadriceps function were assessed at baseline and after 12 weeks. In 12 patients, serial quadriceps muscle biopsies were obtained.6-min walk distance and peak exercise capacity did not change after training. However, endurance capacity improved significantly after training, demonstrated by a shift of the anaerobic threshold to a higher workload (from 32¡5 to 46¡6 W; p50.003) together with an increase in exercise endurance time (p,0.001). Moreover, exercise training increased quadriceps strength by 13% (p50.005) and quadriceps endurance by 34% (p50.001).Training enhanced aerobic capacity of the quadriceps, by increasing capillarisation (1.36¡0.10 to 1.78¡0.13 capillaries per muscle fibre; p,0.001) and oxidative enzyme activity, especially of the type-I (slow) muscle fibres. No changes were found in cross-sectional area and fibre type distribution.Exercise training in iPAH improves exercise endurance and quadriceps muscle function, which is also reflected by structural changes of the quadriceps.
In general, adherence in rehabilitation is high. However, paying attention to patients' nutritional status and creating a positive expectation of treatment during referral and intake appear to be important if one aims to optimise patients' attendance during rehabilitation.
Uptake and drop-out may be related to patients' perceived disabilities, expected benefits and concerns with regard to rehabilitation, practical barriers and confidence in their own capabilities.
BackgroundThe importance of regular physical activity for patients with chronic obstructive pulmonary disease (COPD) is well-established. However, many patients do not meet the recommended daily amount. Accelerometers might provide patients with the information needed to increase physical activity in daily life.ObjectiveOur objective was to assess the validity and usability of low-cost Internet-connected accelerometers. Furthermore we explored patients’ preferences with regards to the presentation of and feedback on monitored physical activity.MethodsTo assess concurrent validity we conducted a field validation study with patients who wore two low-cost accelerometers, Fitbit and Physical Activity Monitor (PAM), at the same time along with a sophisticated multisensor accelerometer (SenseWear Armband) for 48 hours. Data on energy expenditure assessed from registrations from the two low-cost accelerometers were compared to the well validated SenseWear Armband which served as a reference criterion. Usability was examined in a cross-over study with patients who, in succession, wore the Fitbit and the PAM for 7 consecutive days and filled out a 16 item questionnaire with regards to the use of the corresponding deviceResultsThe agreement between energy expenditure (METs) from the SenseWear Armband with METs estimated by the Fitbit and PAM was good (r=.77) and moderate (r=.41), respectively. The regression model that was developed for the Fitbit explained 92% whereas the PAM-model could explain 89% of total variance in METs measured by the SenseWear. With regards to the usability, both the Fitbit and PAM were well rated on all items. There were no significant differences between the two devices.ConclusionsThe low-cost Fitbit and PAM are valid and usable devices to measure physical activity in patients with COPD. These devices may be useful in long-term interventions aiming at increasing physical activity levels in these patients.
Activation of both the complement system and the contact system of intrinsic coagulation is implicated in the pathophysiology of sepsis. Because C1 inhibitor (Cl-Inh) (M, 110,000). Elevated iCl-Inh levels (_ 0.13 ,uM) were found in 81% of all patients, sometimes up to 1.6 MM. Levels of iCl-Inh on admission appeared to be of prognostic value: iCl-Inh was higher in 27 patients who died than in 21 patients who survived (P = 0.003). The mortality in 15 patients with iCl-Inh levels up to 0.2,uM was 27%, but in 12 patients with plasma iCl-Inh exceeding 0.44 gM, the mortality was 83%. The overall mortality in the patients with sepsis was 56%. We propose that the cleavage of Ci-Inh in patients with sepsis reflects processes that play a major role in the development of fatal complications during sepsis.
In line with expectations, results showed that, at baseline, longer time since diagnosis was associated to perceptions corresponding with a chronic illness model (longer illness duration, more experienced consequences, less perceived personal controllability), after correction for clinical variables. After completion of the rehabilitation programme, patients who were more convinced that their participation had led to the achievement of desired outcomes were less concerned about the negative consequences of COPD, had stronger perceptions about the variability in symptoms (cyclical timeline) and had stronger perceptions of personal controllability Conclusions: We conclude that, in accordance with Leventhal et al.'s CSM, coping with an illness is a continuous process and the achievement of desired outcomes during treatment is likely to enable patients to adopt a more positive representation of their illness.
Alpha-2-macroglobulin (ca2M) may function as a proteinase inhibitor in vivo. Levels of this protein are decreased in sepsis, but the reason these levels are low is unknown. Therefore, we analyzed the behavior of ac2M in a baboon model for sepsis. Upon challenge with a lethal (4 baboons) or a sublethal (10 baboons) dose of Escherichia coli, levels of inactivated ac2M (ica2M) steadily increased, the changes being more pronounced in the animals that received the lethal dose. The rise in ica2M significantly correlated with the increase of thrombin-antithrombin IH, plasmin-ar2-antiplasmin, and, to a lesser extent, with that of elastase-adantitrypsin complexes, raising the question of involvement of fibrinolytic, clotting, and neutrophilic proteinases in the inactivation of a2M. Experiments with chromogenic substrates confirmed that thrombin, plasmin, elastase, and cathepsin G indeed had formed complexes with ar2M. Changes in ca2M similar to those observed in the animals that received E. coli occurred in baboons challenged with Staphylococcus aureus, indicating that ar2M formed complexes with the proteinases just mentioned in gram-positive sepsis as well. We conclude that a2M in this baboon model for sepsis is inactivated by formation of complexes with proteinases, derived from activated neutrophils and from fibrinolytic and coagulation cascades. We suggest that similar mechanisms may account for the decreased av2M levels in clinical sepsis.
BackgroundAlthough international guidelines on pulmonary rehabilitation acknowledge that psychological factors contribute to exercise intolerance in patients with chronic obstructive pulmonary disease (COPD), the few empirical studies investigating this association have found inconsistent results.PurposeThe purpose of this study is to investigate whether negative affect and beliefs about exercise of patients with COPD would be related to baseline 6-min walk (6-MW) test results in a pulmonary rehabilitation setting, after correction for physical variables (sex, age, height, weight, and lung function). A second aim was to examine whether patients' beliefs are associated with treatment outcomes, as measured by an improvement in 6-MW distance.MethodA 12-week pulmonary rehabilitation program was completed by 166 patients. Beliefs (perceived necessity and concerns) about exercise and negative affect were assessed by a questionnaire. Clinical data were obtained from medical records.ResultsBaseline 6-MW distance was positively related to younger age, male gender, better pulmonary function, and having fewer concerns about exercise. After rehabilitation, patients had increased their walk distance by 12% (32 m), on average. Baseline physiological and psychological variables were unrelated to patients' response to treatment (increase in walk distance). However, subgroup analysis showed that for patients with mild to moderate airflow obstruction, concerns about exercise were negatively related to response to treatment.ConclusionWe conclude that patients' beliefs about the negative consequences of exercise are associated with baseline 6-MW test performance and response to treatment for patients with mild to moderate COPD. We recommend that patients' concerns about exercise are discussed and, if necessary, corrected during the intake phase.
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