Strength training and aerobic exercise training for muscle disease.

BACKGROUND: Strength training or aerobic exercise programmes, or both, might optimise muscle and cardiorespiratory function and prevent additional disuse atrophy and deconditioning in people with a muscle disease. This is an update of a review first published in 2004 and last updated in 2013. We undertook an update to incorporate new evidence in this active area of research. OBJECTIVES: To assess the effects (benefits and harms) of strength training and aerobic exercise training in people with a muscle disease. SEARCH METHODS: We searched Cochrane Neuromuscular's Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL in November 2018 and clinical trials registries in December 2018. SELECTION CRITERIA: Randomised controlled trials (RCTs), quasi-RCTs or cross-over RCTs comparing strength or aerobic exercise training, or both lasting at least six weeks, to no training in people with a well-described muscle disease diagnosis. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included 14 trials of aerobic exercise, strength training, or both, with an exercise duration of eight to 52 weeks, which included 428 participants with facioscapulohumeral muscular dystrophy (FSHD), dermatomyositis, polymyositis, mitochondrial myopathy, Duchenne muscular dystrophy (DMD), or myotonic dystrophy. Risk of bias was variable, as blinding of participants was not possible, some trials did not blind outcome assessors, and some did not use an intention-to-treat analysis. Strength training compared to no training (3 trials) For participants with FSHD (35 participants), there was low-certainty evidence of little or no effect on dynamic strength of elbow flexors (MD 1.2 kgF, 95% CI -0.2 to 2.6), on isometric strength of elbow flexors (MD 0.5 kgF, 95% CI -0.7 to 1.8), and ankle dorsiflexors (MD 0.4 kgF, 95% CI -2.4 to 3.2), and on dynamic strength of ankle dorsiflexors (MD -0.4 kgF, 95% CI -2.3 to 1.4). For participants with myotonic dystrophy type 1 (35 participants), there was very low-certainty evidence of a slight improvement in isometric wrist extensor strength (MD 8.0 N, 95% CI 0.7 to 15.3) and of little or no effect on hand grip force (MD 6.0 N, 95% CI -6.7 to 18.7), pinch grip force (MD 1.0 N, 95% CI -3.3 to 5.3) and isometric wrist flexor force (MD 7.0 N, 95% CI -3.4 to 17.4). Aerobic exercise training compared to no training (5 trials) For participants with DMD there was very low-certainty evidence regarding the number of leg revolutions (MD 14.0, 95% CI -89.0 to 117.0; 23 participants) or arm revolutions (MD 34.8, 95% CI -68.2 to 137.8; 23 participants), during an assisted six-minute cycle test, and very low-certainty evidence regarding muscle strength (MD 1.7, 95% CI -1.9 to 5.3; 15 participants). For participants with FSHD, there was low-certainty evidence of improvement in aerobic capacity (MD 1.1 L/min, 95% CI 0.4 to 1.8, 38 participants) and of little or no effect on knee extension strength (MD 0.1 kg, 95% CI -0.7 to 0.9, 52 participants). For participants with dermatomyositis and polymyositis (14 participants), there was very low-certainty evidence regarding aerobic capacity (MD 14.6, 95% CI -1.0 to 30.2). Combined aerobic exercise and strength training compared to no training (6 trials) For participants with juvenile dermatomyositis (26 participants) there was low-certainty evidence of an improvement in knee extensor strength on the right (MD 36.0 N, 95% CI 25.0 to 47.1) and left (MD 17 N 95% CI 0.5 to 33.5), but low-certainty evidence of little or no effect on maximum force of hip flexors on the right (MD -9.0 N, 95% CI -22.4 to 4.4) or left (MD 6.0 N, 95% CI -6.6 to 18.6). This trial also provided low-certainty evidence of a slight decrease of aerobic capacity (MD -1.2 min, 95% CI -1.6 to 0.9). For participants with dermatomyositis and polymyositis (21 participants), we found very low-certainty evidence for slight increases in muscle strength as measured by dynamic strength of knee extensors on the right (MD 2.5 kg, 95% CI 1.8 to 3.3) and on the left (MD 2.7 kg, 95% CI 2.0 to 3.4) and no clear effect in isometric muscle strength of eight different muscles (MD 1.0, 95% CI -1.1 to 3.1). There was very low-certainty evidence that there may be an increase in aerobic capacity, as measured with time to exhaustion in an incremental cycle test (17.5 min, 95% CI 8.0 to 27.0) and power performed at VO2 max (maximal oxygen uptake) (18 W, 95% CI 15.0 to 21.0). For participants with mitochondrial myopathy (18 participants), we found very low-certainty evidence regarding shoulder muscle (MD -5.0 kg, 95% CI -14.7 to 4.7), pectoralis major muscle (MD 6.4 kg, 95% CI -2.9 to 15.7), and anterior arm muscle strength (MD 7.3 kg, 95% CI -2.9 to 17.5). We found very low-certainty evidence regarding aerobic capacity, as measured with mean time cycled (MD 23.7 min, 95% CI 2.6 to 44.8) and mean distance cycled until exhaustion (MD 9.7 km, 95% CI 1.5 to 17.9). One trial in myotonic dystrophy type 1 (35 participants) did not provide data on muscle strength or aerobic capacity following combined training. In this trial, muscle strength deteriorated in one person and one person had worse daytime sleepiness (very low-certainty evidence). For participants with FSHD (16 participants), we found very low-certainty evidence regarding muscle strength, aerobic capacity and VO2 peak; the results were very imprecise. Most trials reported no adverse events other than muscle soreness or joint complaints (low- to very low-certainty evidence). AUTHORS' CONCLUSIONS: The evidence regarding strength training and aerobic exercise interventions remains uncertain. Evidence suggests that strength training alone may have little or no effect, and that aerobic exercise training alone may lead to a possible improvement in aerobic capacity, but only for participants with FSHD. For combined aerobic exercise and strength training, there may be slight increases in muscle strength and aerobic capacity for people with dermatomyositis and polymyositis, and a slight decrease in aerobic capacity and increase in muscle strength for people with juvenile dermatomyositis. More research with robust methodology and greater numbers of participants is still required.

Strength training and aerobic exercise training for muscle disease.

BACKGROUND: Strength training or aerobic exercise programmes might optimise muscle and cardiorespiratory function and prevent additional disuse atrophy and deconditioning in people with a muscle disease. This is an update of a review first published in 2004. OBJECTIVES: To examine the safety and efficacy of strength training and aerobic exercise training in people with a muscle disease. SEARCH METHODS: We searched the Cochrane Neuromuscular Disease Group Specialized Register (July 2012), CENTRAL (2012 Issue 3 of 4), MEDLINE (January 1946 to July 2012), EMBASE (January 1974 to July 2012), EMBASE Classic (1947 to 1973) and CINAHL (January 1982 to July 2012). SELECTION CRITERIA: Randomised or quasi-randomised controlled trials comparing strength training or aerobic exercise programmes, or both, to no training, and lasting at least six weeks, in people with a well-described diagnosis of a muscle disease.We did not use the reporting of specific outcomes as a study selection criterion. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted the data obtained from the full text-articles and from the original investigators. We collected adverse event data from included studies. MAIN RESULTS: We included five trials (170 participants). The first trial compared the effect of strength training versus no training in 36 people with myotonic dystrophy. The second trial compared aerobic exercise training versus no training in 14 people with polymyositis and dermatomyositis. The third trial compared strength training versus no training in a factorial trial that also compared albuterol with placebo, in 65 people with facioscapulohumeral muscular dystrophy (FSHD). The fourth trial compared combined strength training and aerobic exercise versus no training in 18 people with mitochondrial myopathy. The fifth trial compared combined strength training and aerobic exercise versus no training in 35 people with myotonic dystrophy type 1.In both myotonic dystrophy trials and the dermatomyositis and polymyositis trial there were no significant differences between training and non-training groups for primary and secondary outcome measures. The risk of bias of the strength training trial in myotonic dystrophy and the aerobic exercise trial in polymyositis and dermatomyositis was judged as uncertain, and for the combined strength training and aerobic exercise trial, the risk of bias was judged as adequate. In the FSHD trial, for which the risk of bias was judged as adequate, a +1.17 kg difference (95% confidence interval (CI) 0.18 to 2.16) in dynamic strength of elbow flexors in favour of the training group reached statistical significance. In the mitochondrial myopathy trial, there were no significant differences in dynamic strength measures between training and non-training groups. Exercise duration and distance cycled in a submaximal endurance test increased significantly in the training group compared to the control group. The differences in mean time and mean distance cycled till exhaustion between groups were 23.70 min (95% CI 2.63 to 44.77) and 9.70 km (95% CI 1.51 to 17.89), respectively. The risk of bias was judged as uncertain. In all trials, no adverse events were reported. AUTHORS' CONCLUSIONS: Moderate-intensity strength training in myotonic dystrophy and FSHD and aerobic exercise training in dermatomyositis and polymyositis and myotonic dystrophy type I appear to do no harm, but there is insufficient evidence to conclude that they offer benefit. In mitochondrial myopathy, aerobic exercise combined with strength training appears to be safe and may be effective in increasing submaximal endurance capacity. Limitations in the design of studies in other muscle diseases prevent more general conclusions in these disorders.

Exercise in inflammatory myopathies, including inclusion body myositis.

Exercise is an important part of treatment in patients with idiopathic inflammatory myopathies. Improved functioning, ability to perform activities of daily living, and health-related quality of life have been reported in adult polymyositis, dermatomyositis, and also recently inclusion body myositis following different exercise regimens, with no signs of increased muscle inflammation. Intensive resistance training could reduce clinical disease activity and reduce expression of genes regulating inflammation and fibrosis in chronic polymyositis and dermatomyositis. Today, exercise research in adult myositis is focused on understanding mechanisms for muscle impairment and improved muscle function in relation to exercise and verifying results from small, open studies in larger settings. There are no studies evaluating the effects of exercise over weeks or months in juvenile dermatomyositis, other than a case report; however, there is to our knowledge an ongoing effort to evaluate the safety and effects of exercise in patients with juvenile dermatomyositis.

[Special training therapy to reduce inflammation in Anti-Jo-1 syndrome]. / Spezielle Trainingstherapie zur Reduktion der Inflammation bei Anti-Jo-1-Syndrom.

A 46-year-old patient was frequently seen with a medically treated Anti-Jo-1 syndrome. The patient had already been treated with azathioprine and oral corticosteroids on account of decreasing lung function, dyspnoea, fatigue, and beginning signs of myositis. Although high doses of steroids and azathioprine were administered, the muscleskeletal syndromes increased steadily. The patient used to be an active long-distance runner (20 km), but now was unable to perform that kind of physical exercise. It was decided to start a treatment with the GalileoTM training device for active muscle training of the lower extremities. Before and after three months of training the following assessment was performed: measurement of health-related quality of life (St. Georges respiratory questionnaire, SGRQ), ultrasound measurement of the cross-sectional area of the quadriceps muscle, 6 minute walk test (6 MWT), lung function testing, and assessment of serum markers of inflammation (TNF-alpha, interleukin-8, CRP, CK, myoglobin). After only two months, training with the GalileoTM five times a week has improved the patient's conditions dramatically. The training will be continued.

Exercise effects in patients with adult idiopathic inflammatory myopathies.

PURPOSE OF REVIEW: To give an update on recent findings on effects of exercise in patients with adult inflammatory myopathies. RECENT FINDINGS: Although responding to treatment, a majority of patients with polymyositis and dermatomyositis develop sustained disability. The reason for this is not clear. However, a recent study further supports the hypothesis of hypoxia in muscle tissue as a contributor to muscle weakness. The percentage of type I oxygen-dependent muscle fibers increased after a 12-week submaximal home exercise program along with improved muscle endurance in patients with chronic polymyositis or dermatomyositis. Creatine supplements in addition to the same home exercise program are more beneficial than exercise alone in patients with chronic polymyositis or dermatomyositis. Patients with chronic disease tolerate intensive resistance training resulting in improved muscle strength and muscle endurance. This 7-week exercise study also reported reduced disease activity and possibly even reduced muscle inflammation. SUMMARY: These recent studies are in line with earlier ones further supporting safety and efficacy of exercise in patients with polymyositis or dermatomyositis. There is an urgent need for larger randomized controlled trials also including patients with inclusion body myositis to further increase knowledge of disease mechanisms causing disability, exercise effects, and what exercise program is most efficient in patients with different entities of idiopathic inflammatory myopathies.

[Churg-Strauss syndrome presenting as polymyositis: report of a case]. / La sindrome di Churg-Strauss ad esordio polimiositico: descrizione di un caso clinico.

We reported the case of a male patient with Churg-Strauss syndrome (CSS) heralding as symptoms typical of polymiositis. During high-dose cortisone therapy (1.5 mg/kg/day), he developed a severe multiplex mononeuritis, poorly responsive to immunoglobulins and methotrexate administration. After 6 months he developed a partial deficiency of the right sciatic popliteus and the radial nerves. Sural nerve biopsy showed a characteristic necrotizing vasculitis of the epineural vessels with granulocyte and eosinophil infiltrates. In the course of CSS, peripheral nervous system involvement is frequent and can lead to disability. For this reason, it must be promptly recognized and properly treated.

Physical exercise among patients with systemic autoimmune myopathies.

Systemic autoimmune myopathies (SAMs) are a heterogeneous group of rare systemic autoimmune diseases that primarily affect skeletal muscles. Patients with SAMs show progressive skeletal muscle weakness and consequent functional disabilities, low health quality, and sedentary lifestyles. In this context, exercise training emerges as a non-pharmacological therapy to improve muscle strength and function as well as the clinical aspects of these diseases. Because many have feared that physical exercise exacerbates inflammation and consequently worsens the clinical manifestations of SAMs, it is necessary to evaluate the possible benefits and safety of exercise training among these patients. The present study systematically reviews the evidence associated with physical training among patients with SAMs.

Classification and treatment of the juvenile idiopathic inflammatory myopathies.

This article reviews the current status of the classification and treatment of the juvenile idiopathic inflammatory myopathies. The intent of classification is to define homogeneous groups that share similar clinical features, disease courses, and responses to therapy. The classification scheme proposed includes clinicopathologic subsets, serologic subjects based on the presence of myositis-specific and myositis-associated autoantibodies, and environmental triggers of myositis. Juvenile dermatomyositis is the most common and widely recognized of these disorders. The second part reviews the history of treatment of juvenile dermatomyositis and discusses agents to consider for patients with refractory disease, unacceptable steroid toxicity, or poor prognostic factors.

Occupational therapy management of a patient with severe polymyositis.

The purpose of this article is to illustrate with a case study the process through which a patient with polymyositis taking part in an occupational therapy program achieved functional improvement in spite of persistent muscle weakness. Although the focus is on the occupational therapy program, close monitoring of patient improvement or regression by the total rehabilitation team was essential in order to adjust the patient's weekly activity level for maximum benefit.

Functional outcome of myositis patients: can a low-dose glucocorticoid regimen achieve good functional results?

OBJECTIVE: During the last few years, in an attempt to reduce the side effects of glucocorticoid (GC) therapy, we have been treating polymyositis-dermatomyositis (PM-DM) patients with a lower starting dose of GC than is classically recommended. In order to validate this approach, we performed a functional re-evaluation of these PM-DM patients. METHODS: A comprehensive protocol evaluating muscle strength, muscle function, CK levels, persistence of spontaneous activity on electromyography, disability in daily life activities and degree of dependence was applied in 25 non-cancer-associated biopsy-proven PM-DM patients, 15 of whom had been treated with a high-dose regimen (i.e. > 0.5 mg prednisolone/kg/day) and 10 with a low-dose regimen (i.e. < or = 0.5 mg prednisolone/kg/day). RESULTS: Our results indicate that the functional outcome of PM-DM patients given a low-dose starting regimen of GC does not differ from that observed in patients given higher doses. Interestingly, vertebral fractures were less common in patients treated with lower GC doses. CONCLUSIONS: Although our analysis has certain shortcomings, including the small number of patients investigated and their uncontrolled assignment to a low-dose or a high-dose GC regimen, the results of this retrospective study suggest that a low-dose starting regimen of GC can achieve a good functional outcome in PM-DM patients, with a reduction of treatment-related disability. This approach would be welcome as a step forward should it be validated by a longitudinal study.

Abnormal lactate levels in patients with polymyositis and dermatomyositis: the benefits of a specific rehabilitative program.

BACKGROUND: Polymyositis (PM) and Dermatomyositis (DM) are chronic, inflammatory and autoimmune skeletal muscle disorders characterized by reduced muscle strength, fatigue and myalgia. While inflammation causes muscle damage in the early phase, metabolic alterations such as an impairment of oxidative metabolism seem to be responsible for the disability in the chronic phase of the disease. AIM: To assess muscle oxidative efficiency and to test the effect of aerobic training in a group of PM/DM patients. DESIGN: A case-control study and a within-group comparison. SETTING. Outpatients of the Unit of Neurorehabilitation of the University Hospital of Pisa. POPULATION: 20 patients with myositis (15 PM and 5 DM) and 15 healthy subjects as a control group. METHODS: The test consisted of an incremental, sub-maximal aerobic exercise on a treadmill; haematic lactate was assessed at rest and after 1', 5', 10' and 30' minutes from the end of the exercise. A within-group comparison was conducted on four of the PM patients (P group). They were subjected to six weeks aerobic training. Lactate curve and functional tests were assessed before and after the treatment. RESULTS: A precocious fatigability and significantly higher values of lactate at rest and after the exercise were observed in patients. In the P group mean lactate levels were significantly decreased after the treatment and an improvement of muscle performance was observed. CONCLUSION: Abnormal blood lactate levels suggested an impaired muscle oxidative efficiency in PM/DM patients. A specific aerobic training program reduced lactate levels and relieved fatigue symptoms in a within-group of four of the PM patients. CLINICAL REHABILITATION IMPACT: Such a specific aerobic training program could be introduced in everyday practice for the rehabilitative treatment of PM/DM patients.

Improved exercise performance and increased aerobic capacity after endurance training of patients with stable polymyositis and dermatomyositis.

INTRODUCTION: This randomized, controlled study on patients with polymyositis or dermatomyositis was based on three hypotheses: patients display impaired endurance due to reduced aerobic capacity and muscle weakness, endurance training improves their exercise performance by increasing the aerobic capacity, and endurance training has general beneficial effects on their health status. METHODS: In the first part of this study, we compared 23 patients with polymyositis or dermatomyositis with 12 age- and gender-matched healthy controls. A subgroup of patients were randomized to perform a 12-week endurance training program (exercise group, n = 9) or to a non-exercising control group (n = 6). We measured maximal oxygen uptake (VO2 max) and the associated power output during a progressive cycling test. Endurance was assessed as the cycling time to exhaustion at 65% of VO2 max. Lactate levels in the vastus lateralis muscle were measured with microdialysis. Mitochondrial function was assessed by measuring citrate synthase (CS) and ß-hydroxyacyl-CoA dehydrogenase (ß-HAD) activities in muscle biopsies. Clinical improvement was assessed according to the International Myositis Assessment and Clinical Studies Group (IMACS) improvement criteria. All assessors were blinded to the type of intervention (that is, training or control). RESULTS: Exercise performance and aerobic capacity were lower in patients than in healthy controls, whereas lactate levels at exhaustion were similar. Patients in the exercise group increased their cycling time, aerobic capacity and CS and ß-HAD activities, whereas lactate levels at exhaustion decreased. Six of nine patients in the exercise group met the IMACS improvement criteria. Patients in the control group did not show any consistent changes during the 12-week study. CONCLUSIONS: Polymyositis and dermatomyositis patients have impaired endurance, which could be improved by 12 weeks of endurance training. The clinical improvement corresponds to increases in aerobic capacity and muscle mitochondrial enzyme activities. The results emphasize the importance of endurance exercise in addition to immunosuppressive treatment of patients with polymyositis or dermatomyositis. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01184625.

Intensive aerobic training improves motor performances and oxidative metabolism efficiency in chronic polymyositis: a case report.

We describe the case of a 64-year-old woman affected by chronic polymyositis with gait disturbance, fatty replacement and swelling of thigh muscles. She achieved significant clinical improvement after 5 weeks intensive aerobic training. In particular the patient improved in motor performance tests, showed an improvement in the efficiency of oxidative metabolism and quality of life. Furthermore, analysis of creatinephosphokinase levels showed a reduction of muscle damage susceptibility. In conclusion, a specific intensive exercise program can be safely used with beneficial effects on muscle function in patients with chronic polymyositis.

Intensive exercise and a patient in acute phase of polymyositis.

BACKGROUND AND OBJECTIVE: Polymyositis (PM) is an idiopathic inflammatory myopathy manifested by proximal limb muscles weakness, elevated creatinin kinase, electromyography changes, and muscle inflammation in biopsy. We report an instance of intensive rehabilitation therapy in a patient with clinically active polymyositis. CASE REPORT: A 19-year-old female patient, diagnosed with 'electromyography and biopsy proven' polymyositis for 5 years, suffered from worsening limbs weakness and dysphagia. In her history, she had upper and lower limbs weakness accompanied by dysphagia which was further complicated by right bronchial aspiration 9 months ago. A four-week trial of intensive training and exercise rehabilitation, concurrently accompanied by medications was prescribed for this patient. At the end of therapy she achieved significant improvement in muscle strength, activities of daily living, and ambulation without any disease exacerbation. CONCLUSION: We concluded that short-term intensive training and exercise may lead to improvements in patients with PM, without causing a progress in the disease. Due to the rarity of PM and difficulty of conducting well-controlled studies to examine the risks and benefits of exercise in these patients, further research is necessary to investigate benefits of exercise training in active phase of disease.

Benefits of intensive resistance training in patients with chronic polymyositis or dermatomyositis.

OBJECTIVE: To investigate the benefits and safety of an intensive muscular training program in patients with chronic polymyositis (PM) and dermatomyositis (DM). METHODS: Nine patients with chronic PM or DM (median age 53 years, range 44-61) were included. Assessments of impairment (10-15 voluntary repetition maximum [VRM], the Functional Index 2 [FI-2], the Grippit, and pain rated on the Borg CR-10 scale), activity limitation (Myositis Activities Profile), and participation restriction (patients' disease impact on well-being) were performed 4 weeks prior to baseline, at baseline, and after 7 weeks of exercise. A 6-item core set of disease activity measures was administered and muscle biopsy samples of vastus lateralis were obtained at baseline and after 7 weeks of exercise. Response criteria at an individual level were set for disability and disease activity. The patients exercised 3 days per week for 7 weeks on loads allowing 10 VRM. RESULTS: On a group level there were no significant differences between assessments at 4 weeks before baseline compared with baseline. The group improved significantly regarding 10-15 VRM and FI-2 at 7 weeks compared with baseline (P < 0.05). All patients were responders with respect to impairment and 2 were activity limitation responders whereas participation restriction remained unchanged in all. Two patients were responders with reduced disease activity and no patient had signs of increased muscle inflammation in the muscle biopsy sample after 7 weeks of exercise. CONCLUSION: Patients with chronic, stable PM and DM can perform this intensive resistive exercise program with beneficial effects on impairment and activity limitation without increased muscle inflammation.

Effect of physical training on the proportion of slow-twitch type I muscle fibers, a novel nonimmune-mediated mechanism for muscle impairment in polymyositis or dermatomyositis.

OBJECTIVE: To compare muscle fiber type composition and muscle fiber area in patients with chronic polymyositis or dermatomyositis and healthy controls, and to determine whether physical training for 12 weeks could alter these muscle characteristics. METHODS: Muscle fiber type composition and muscle fiber area were investigated by biochemical and immunohistochemistry techniques in repeated muscle biopsy samples obtained from 9 patients with chronic myositis before and after a 12-week exercise program and in healthy controls. Muscle performance was evaluated by the Functional Index (FI) in myositis and by the Short Form 36 (SF-36) quality of life instrument. RESULTS: Before exercise, the proportion of type I fibers was lower (mean +/- SD 32% +/- 10%) and the proportion of type IIC fibers was higher (3% +/- 3%) in patients compared with healthy controls. After exercise, percentage of type I fiber increased to 42% +/- 13% (P < 0.05), and type IIC decreased to 1% +/- 1%. An exercise-induced 20% increase of the mean fiber area was also observed. The functional capacity measured by the FI in myositis and the physical functioning subscale of the SF-36 increased significantly. Improved physical functioning was positively correlated with the proportion of type I fibers (r = 0.88, P < 0.01) and type II muscle fiber area (r = 0.70, P < 0.05). CONCLUSION: Low muscle endurance in chronic polymyositis or dermatomyositis may be related to a low proportion of oxidative, slow-twitch type I fibers. Change in fiber type composition and increased muscle fiber area may contribute to improved muscle endurance and decreased muscle fatigue after a moderate physical training program.

Functional outcome and quality of life in adult patients with idiopathic inflammatory myositis.

OBJECTIVES: To present the outcome of patients with idiopathic inflammatory myositis, focusing on functional ability and quality of life. METHODS: Analysis was performed using data from 105 adult patients with definitive polymyositis, dermatomyositis or overlap myositis, who were followed up at a single centre. The diagnosis was made between 1979 and 2000 based on Bohan and Peter's criteria. Functional ability was assessed after a minimum follow-up of 3 yr with the Health Assessment Questionnaire Disability Index (HAQDI) and quality of life was measured with the Short Form 36-item questionnaire (SF-36). RESULTS: Fifteen patients in our cohort died and 87 participated in the evaluation of functional outcome. Functional ability after a median follow-up of 107.1 months (range 36.4-273.3) was heterogeneous. The median HAQDI score was 0.875 (range 0-2.875). Polyphasic or chronic-progressive disease course, osteoporosis and long-term follow-up were predictive of higher HAQDI scores. In terms of quality of life, significant differences from population norms were shown in all domains of the SF-36. There were no significant differences in the SF-36 scores among the patients according to clinicopathological subset or disease course. CONCLUSIONS: Although the mortality of our cohort was favourable, myositis continues to have a great impact on life in the medium and long term. The present work indicates that myositis patients have a significantly poorer quality of life than the normal population, but there was no difference among the patients according to clinicopathological subsets.

Benefit of 6 months long-term physical training in polymyositis/dermatomyositis patients.

OBJECTIVE: The benefit of long-term physical training in patients with chronic polymyositis or dermatomyositis (PM/DM) was studied prospectively. METHODS: Eight patients with chronic PM/DM participated in a training programme for 6 months. A group of five PM/DM patients without any physical training was observed for control purposes. RESULTS: While there was no significant change in serum creatine phosphokinase (CPK) levels, the 'activities of daily living (ADL)' score improved significantly (P < 0.03), peak isometric torque (PIT) generated by muscle groups in the lower extremities rose significantly (P < 0.03) and there was a statistically highly significant increase in peak oxygen uptake (VO2max) relative to body weight (P < 0.02) due to the long-term training. The patients improved their aerobic capacity by 28%, which is clinically significant. In the untrained patients, no improvement in these target parameters was observed. CONCLUSION: In clinically stable DM/PM patients, long-term physical training can safely be performed and is recommended as part of a comprehensive rehabilitation management, particularly in view of the cardiopulmonary risk in these patients.

Resistive exercise in the rehabilitation of polymyositis/dermatomyositis.

OBJECTIVE: To determine the effect of a resistive exercise program in the rehabilitation of patients with polymyositis/dermatomyositis (PM/DM). METHODS: Five patients participated in a rehabilitation program that included resistive exercises. In 4 of the patients, these exercises were randomly alternated with nonresistive exercise. Each type of exercise was assigned for periods of 2 weeks, and at the end of each one, muscle strength was measured by means of manual muscle testing (MMT), an activities of daily living (ADL) score, and peak isometric torque (PIT) generated by muscle groups in the lower extremities. Creatine phosphokinase (CPK) levels were used to measure disease activity. The acute response to resistive exercise was studied in 4 of the patients by measuring serial levels of CPK following a session on an exercise bicycle. RESULTS: Of the 4 patients who participated in both types of exercises, 3 experienced increases in strength during both resistive and nonresistive exercise periods. The patient who participated only in resistive exercises had considerable improvements in muscle strength. One patient made no improvements in strength with either type of exercise. None of the patients experienced clinically significant elevations in CPK attributable to either type of exercise. Following a session of resistive exercise, the mean CPK elevation in 4 patients was 7.7%, returning to pre-exercise levels by 8 h in all cases. CONCLUSIONS: Patients with PM/DM may participate in a rehabilitation program which includes resistive exercises. Such programs may be accompanied by increased strength without clinically significant rises in serum levels of muscle enzymes.