In the present investigation, the benefit of physical training in patients with inflammatory myopathy was studied. In this prospective .... Monday after a weekend recovery phase without .... non-normality of the data of this prospective, random-.
British Journal of Rheumatology 1998;37:196–200
IMPROVEMENT OF PHYSICAL FITNESS AND MUSCLE STRENGTH IN POLYMYOSITIS/DERMATOMYOSITIS PATIENTS BY A TRAINING PROGRAMME G. F. WIESINGER, M. QUITTAN, M. ARINGER,* A. SEEBER,‡ B. VOLC-PLATZER,† J. SMOLEN* and W. GRANINGER* Department of Physical Medicine and Rehabilitation, *Department of Internal Medicine, Division of Rheumatology, †Department of Dermatology, Division of Immunology, Allergy and Infectious Disease and ‡Division of General Dermatology, University of Vienna, Austria SUMMARY In the present investigation, the benefit of physical training in patients with inflammatory myopathy was studied. In this prospective, randomized, controlled study, 14 patients with polymyositis (PM ) or dermatomyositis (DM ) were investigated. The training, consisting of bicycle exercise and step aerobics, took place over a 6 week period. Baseline and endpoint measurements included an ‘activities of daily living’ (ADL) score, peak isometric torque (PIT ) generated by muscle groups in the lower extremities, peak oxygen consumption ( VO max), and creatine phosphokinase (CPK ) levels. There was no significant 2 rise in disease activity in the training group in comparison to the controls. The ADL score for the treatment group, in comparison to the control group, improved (P < 0.02), PIT rose (P < 0.05) and there was a statistically significant increase in oxygen uptake relative to body weight (P < 0.05). No rise in inflammatory activity, but significant improvement in muscle strength, oxygen uptake and well-being, were found in patients with inflammatory myopathy as a result of physical training. Besides medication, a physical training programme consisting mainly of concentric muscle contractions should therefore be an integral part of therapy, particularly in view of the cardiopulmonary risk of these patients. K : Polymyositis, Dermatomyositis, Physical training, Rehabilitation, Rheumatology, Dermatology.
P and dermatomyositis (PM/DM ) are inflammatory myopathies of unknown aetiology. Muscle weakness, myalgias and sometimes generalized fatigue lead to malaise and to decreased use of striated muscles [1]. In addition, cardiac abnormalities and pulmonary involvement may restrain cardiovascular fitness [2–7]. Decreased muscle activity leads to further atrophy of muscle fibres and a decrease in cardiorespiratory training status. Despite these facts, many physicians recommend a reduction in physical activity since it is feared that the use of inflamed tissue would further worsen the inflammatory process [1, 8–10]. In many chronic diseases, a controlled muscle training and exercise programme has been shown to result in an improvement in the clinical symptoms [11–15]. Therefore, we hypothesized that also in myositis, at least during stable phases of chronic muscle inflammation, controlled muscle training might be of benefit to the well-being and cardiorespiratory fitness of the patients. In this prospective, controlled study of a physical exercise programme in chronic myositis patients, we evaluated its effects on (a) disease activity, (b) wellbeing, (c) muscle strength and (d ) cardiorespiratory fitness. We show that the training programme does not have negative effects on disease activity, but led to significant improvement of the variables investigated and thus to overall benefit to the patients.
MATERIALS AND METHODS Study design Patients. Patients were entered into this prospective, randomized and controlled study if they met the following criteria. (1) Established DM or PM with a disease duration of >6 months. (2) Clinical activity defined as the presence of proximal muscle weakness, characterized clinically by a reduced ability to climb stairs, to cross one leg over the other, to rise from a squatting position, to rise from a seated position, to comb the hair; and/or by the elevation of serum muscle enzyme values [creatine phosphokinase (CPK ) levels above the upper limit of normal (70 IU/l ) on three or more consecutive observations during the preceding 3 month period ]. (3) The drug therapy had to be stable for at least 3 months before the start of the training programme. Exclusion criteria were clinically manifest pulmonary or cardiac disorders, inclusion body myositis, fever, neoplasms, physical inability of patients to exercise, or increase in muscle destruction during the past 3 months before the start of the training programme, as indicated by at least a 50% increase in CPK levels over the baseline value. Fourteen consecutive patients (nine women and five men) between 24 and 70 yr of age (median 51), who met these criteria, were entered into the study. All patients had a diagnosis of primary inflammatory muscle disease as defined by the established criteria of Bohan and Peter [16 ]. In all patients, muscle biopsies, electromyograms and laboratory studies had been performed to establish the diagnosis. Nine out of the
Submitted 24 February 1997; revised version accepted 25 June 1997. Correspondence to: W. Graninger, Division of Rheumatology, Department of Internal Medicine III, University of Vienna, Vienna General Hospital, Waehringer Guertel 18–20, A-1090, Vienna, Austria.
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14 suffered from DM and five had PM. In all patients, medication was kept constant for the study period. Nine patients were treated with prednisolone (up to 25 mg/day); four patients received high-dose i.v. immunoglobulins; two patients had azathioprine, 100 mg/day, and two other patients received cyclosporin A; one patient was treated with a non-steroidal anti-inflammatory drug only. The characteristics of patients with DM and PM were similar ( Table I ). None of the patients had participated in regular physical exercise for 2 yr before inclusion in our study. Randomization. The study was conducted at the University Hospital of Vienna following approval by the local ethical committee. Informed consent was obtained from all patients before they were randomly assigned either to the training group ( TG) or to the control group (CG). Distinct randomization lists were used. According to the decision of the ethical committee, the patients in the control group were also to be guaranteed participation in the training programme at the end of the study, if it should prove beneficial. Description of exercise regime Patients in the training group took part in a 6 week training programme which included a mixed programme of stationary cycling and step aerobics. Each exercise session lasted for 1 h. Cycling was slowly increased on an individual basis. Following a 3–5 min warm-up phase, resistance was increased until a heart rate of 60% of the previously established maximum heart rate was reached. If the patient reported increased muscle tenderness from the preceding exercise, the resistance was decreased to a previously tolerated amount. Every training session also included one halfhour of step aerobics. The last 5 min were used for cool-down and stretching exercises. Because of the different rate levels, the training load of this exercise could be adjusted and changed. During the first 2 weeks, training was carried out twice weekly and three times weekly during the remaining 4 weeks. The training was guided by a physiotherapist and supervised by the authors regularly. The patients were allowed to carry out an additional training programme, such as stationary cycling at home, if they so wished. Patients in the control group did not undergo any training and continued their previous way of life.
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Assessment of efficacy and unwanted effects Laboratory assessment. Elevated serum levels of enzymes, such as CPK and aldolase, which leak from injured skeletal muscle are valuable aids in detecting active muscle inflammation [17]. In order to determine the effects of training on the degree of muscle destruction, these two enzymes were measured weekly on Monday after a weekend recovery phase without exercise. Functional assessment. For describing individual abilities and limitations, we used a modified Functional Assessment Screening Questionnaire. This questionnaire has been well described [18] and used for evaluating disability [19]. The questionnaire was used in a German translation. Questionnaires for functional assessment have been validated in many languages, including German [20, 21], and have proved useful across many language and cultural barriers [22–24]. The patients had to fill in the questionnaires at the beginning and at the end of the 6 weeks observation period. Since the use of visual analogue scale ( VAS) anchors that clearly indicate extremes appears to have the greatest sensitivity and is the least susceptible to bias or distortions in rating [25, 26 ], a 10-cm-long VAS was used for each question. Measurement of muscle strength. Muscle strength was determined in the TG and the CG before and at the end of the 6 weeks observation period. The muscle strength of the hip flexors and the knee extensors on the right and on the left side was analysed by a computerized isokinetic system (CYBEX 6000 Isokinetic dynamometer, Lumex Inc., New York), which measures the peak isometric torque (PIT ). CYBEX assessment was carried out by the same person who was unaware of the group to which individual patients belonged. Bilaterally, the extensors of the knee in the seated position, and the flexors of the hip in the supine position, were tested. The patients had to perform maximal isometric contractions and, during these measurements, the best of three attempts by the individual patient was recorded. The results of the PIT are expressed as the sum of values obtained for the four muscle groups (hip flexors and knee extensors on both legs) [27]. The CYBEX system has been used extensively to assess muscle strength in normal and in some diseased
TABLE I Clinical characteristics of study patients Characteristics Age (yr) (median, range) Sex (f/m) PM/DM CPK level elevated above upper limit of normal (y/n) ADL score (mean ± ...) PIT (Nm) (mean ± ...) VO max (ml/min/kg) (mean ± ...) 2
Training group (n = 7)
Control group (n = 7)
56 (44–68) 4/3 2/5 7/0
40 (24–70)* 5/2 2/5 4/3
156.6 (±9.7) 633.1 (±100) 17.4 (±1)
142.6 (±19.8)* 435 (±82)* 16.9 (±1.8)*
*No statistically significant differences between the training and control group.
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populations, and has been reported to give valid and reliable results [28]. The detailed method has been outlined previously and its utility in the assessment of strength in patients with inflammatory muscle disease has been described [29]. Exercise testing. Exercise studies were performed using a symptom-limited, incremental cycle ergometer protocol. Pedalling at 50–60 r.p.m., the work rate was increased every 2 min by 25 W from an initial load of 25 W. Ventilatory parameters were collected breath by breath using a computer-based device (Sensor Medics 2900 System, Sensormedics, Yorba Linda, LA, CA, USA) and 20 s averages for each parameter were registered. Patients breathed through a mouthpiece connected to a mass flowmeter (Sensor Medics, CA, USA), measuring minute ventilation by the thermal conductivity technique. Oxygen uptake ( VO ) was 2 measured with a fast-response zirconium oxide analyser (Servomex-Taylor, Fussex). The anaerobic threshold was determined by using the V slope technique [30]. Samples of whole blood were taken from the hyperaemized earlobe at rest, within the last 20 s of each work rate, and at maximal exercise with a 20 ml capillary to assess lactate concentration ( ESAT 6661, Eppendorf, Hamburg, Germany). The heart rate and rhythm were recorded continuously at rest and throughout exercise with a 12-lead electrocardiogram (Siemens, Germany). Maximal oxygen uptake ( VO max) was defined as the highest O consumption 2 2 obtained during the symptom-limited exercise test [31]. In order to examine the effects of the training, values for VO max (ml/min/kg) at initiation and at the end 2 of the study were compared.
Statistical analysis Descriptive statistics (means, ..., median, range) were performed for all dependent variables. In order to determine changes in each patient, the differences in the variable values between baseline and endpoint were determined. Owing to the small sample sizes and non-normality of the data of this prospective, randomized, controlled trial, exact non-parametric tests were used. The exact Wilcoxon signed rank test was used to test for significant changes in the variable values before and after the training programme within the groups. The exact Mann–Whitney U-test was used to compare these changes between the two groups. Both were performed using the software system StatXactTurbo (CYTEL Software Corporation, 1992, Cambridge, MA, USA). A P value of
