Exercise therapy for idiopathic inflammatory myopathies
Encyclopedia
Although they vary in particulars, polymyositis
, dermatomyositis
and inclusion body myositis
are idiopathic inflammatory myopathies (IIM)http://www.ninds.nih.gov/disorders/inflammatory_myopathies/detail_inflammatory_myopathies.htm primarily characterized by chronic inflammation
of human skeletal muscle
tissue that ultimately causes the necrosis
of muscle cells. This degeneration leads to muscle tissue wasting, weakness and fatigue among other serious effects. Until recently, exercise has been avoided as a type of therapy, and even forbidden due to the risk of triggering or amplifying inflammation. However, several studies have been conducted to test this assumption and have shown that aerobic exercise
as well as resistance training
can maintain and even improve quality of life for IIM-affected individuals without increased inflammatory response.
training was applied for four weeks resulting in isometric peak power at 60% of maximal voluntary contraction. The increase in isometric power was later shown to have no significant effect on serum creatine kinase
(CK) after two weeks of strength training
.
three times per week set at 60% maximum heart rate (predicted by age) resulted in increased VO2 max (ie maximal oxygen consumption or aerobic capacity), diminished pain, reduced muscle impairment, and improved quality of life.
and aldolase
, and no increase in muscle inflammation. In 2001, 22 patients were placed on a three week physical therapy and exercise program, and found that creatine kinase levels actually dropped in 20 of the patients.
The longest study to date was a six-month exercise program demonstrating a significant improvement in exercise capacity, VO2, isokinetic strength, and the ability to perform daily tasks compared to controls.
through the effects of IIM, and patients with inclusion body myositis may also be able to prevent contracture and extend functional daily activities through stretching and range of motion exercises
However, the results of these exercise studies, at minimum, show that exercise can attenuate muscle damage due to disease, inactivity and steroid use. They reflect the benefit of exercise through the strengthening of complement (non-diseased) muscles, and should encourage further studies to confirm whether diseased muscle may experience regeneration. The definition of improvement must be established, and reproducible longitudinal studies must be conducted to determine the efficacy of exercise as therapy for IIM.
Polymyositis
Polymyositis is a type of chronic inflammation of the muscles related to dermatomyositis and inclusion body myositis.-Signs and symptoms:...
, dermatomyositis
Dermatomyositis
Dermatomyositis is a connective-tissue disease related to polymyositis and Bramaticosis that is characterized by inflammation of the muscles and the skin.- Causes :...
and inclusion body myositis
Inclusion body myositis
Inclusion body myositis is an inflammatory muscle disease, characterized by slowly progressive weakness and wasting of both distal and proximal muscles, most apparent in the muscles of the arms and legs...
are idiopathic inflammatory myopathies (IIM)http://www.ninds.nih.gov/disorders/inflammatory_myopathies/detail_inflammatory_myopathies.htm primarily characterized by chronic inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
of human skeletal muscle
Skeletal muscle
Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...
tissue that ultimately causes the necrosis
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
of muscle cells. This degeneration leads to muscle tissue wasting, weakness and fatigue among other serious effects. Until recently, exercise has been avoided as a type of therapy, and even forbidden due to the risk of triggering or amplifying inflammation. However, several studies have been conducted to test this assumption and have shown that aerobic exercise
Aerobics
Aerobics is a form of physical exercise that combines rhythmic aerobic exercise with stretching and strength training routines with the goal of improving all elements of fitness...
as well as resistance training
Resistance training
Resistance training has two different meanings. A broader meaning that refers to any training that uses a resistance to the force of muscular contraction , and elastic or hydraulic resistance, which refers to a specific type of strength training that uses elastic or hydraulic tension to provide...
can maintain and even improve quality of life for IIM-affected individuals without increased inflammatory response.
Isometric Activity
In 1993, isometric exerciseIsometric exercise
Isometric exercise or isometrics are a type of strength training in which the joint angle and muscle length do not change during contraction...
training was applied for four weeks resulting in isometric peak power at 60% of maximal voluntary contraction. The increase in isometric power was later shown to have no significant effect on serum creatine kinase
Creatine kinase
Creatine kinase , also known as creatine phosphokinase or phospho-creatine kinase , is an enzyme expressed by various tissues and cell types. CK catalyses the conversion of creatine and consumes adenosine triphosphate to create phosphocreatine and adenosine diphosphate...
(CK) after two weeks of strength training
Strength training
Strength training is the use of resistance to muscular contraction to build the strength, anaerobic endurance, and size of skeletal muscles. There are many different methods of strength training, the most common being the use of gravity or elastic/hydraulic forces to oppose muscle contraction...
.
Aerobic Activity
A six-week training program in 1998 that included 30 minutes of aerobic activityAerobic exercise
Aerobic exercise is physical exercise of relatively low intensity that depends primarily on the aerobic energy-generating process. Aerobic literally means "living in air", and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism...
three times per week set at 60% maximum heart rate (predicted by age) resulted in increased VO2 max (ie maximal oxygen consumption or aerobic capacity), diminished pain, reduced muscle impairment, and improved quality of life.
Weight Bearing Activity
The results produced by aerobic activity were repeated in 1999 where for 12 weeks, weight-bearing exercise was added for patients not exhibiting marked physical incapacity as measured by the Functional Index in Myositis. http://rheumatology.oxfordjournals.org/cgi/content/full/39/1/7 (see Functional Assessment section). Confirmed by MRI and muscle biopsy, both the 1998 and 1999 studies showed that there were no significant changes in levels of creatine kinaseCreatine kinase
Creatine kinase , also known as creatine phosphokinase or phospho-creatine kinase , is an enzyme expressed by various tissues and cell types. CK catalyses the conversion of creatine and consumes adenosine triphosphate to create phosphocreatine and adenosine diphosphate...
and aldolase
Aldolase
Aldolase A is an enzyme that catalyses a reverse aldol reaction: The substrate, fructose 1,6-bisphosphate is broken down into glyceraldehyde 3-phosphate and dihydroxyacetone phosphate . This reaction is a part of glycolysis. Three aldolase isozymes , encoded by three different genes, are...
, and no increase in muscle inflammation. In 2001, 22 patients were placed on a three week physical therapy and exercise program, and found that creatine kinase levels actually dropped in 20 of the patients.
The longest study to date was a six-month exercise program demonstrating a significant improvement in exercise capacity, VO2, isokinetic strength, and the ability to perform daily tasks compared to controls.
Stretching and Range of Motion Activity
Chest expansion and thoracic extension exercises may offer preventive support to those at risk of restrictive lung diseaseRestrictive lung disease
Restrictive lung diseases are a category of extrapulmonary, pleural, or parenchymal respiratory diseases that restrict lung expansion, resulting in a decreased lung volume, an increased work of breathing, and inadequate ventilation and/or oxygenation...
through the effects of IIM, and patients with inclusion body myositis may also be able to prevent contracture and extend functional daily activities through stretching and range of motion exercises
Monitoring
It is important to recognize that all described exercise programs were conducted by physicians or physiotherapists during the stable phase of the disease (except Painelli). Patients were monitored closely for indicators of deleterious effects, such as increases in serum creatine kinase, inflammation or weakness. Monitoring of this kind can only be done in conjunction with a medical team who is aware of the risks posed by increased inflammatory response in patients with IIM.Further Study is Needed
The pathophysiology of IIMs is not well understood. Muscle weakness can be caused by a single or combined effect on muscle tissue by inflammation, inflammatory infiltrates, muscle atrophy, metabolic abnormalities that indicate disordered energy metabolism, and possibly neuropathy, among others. Therefore physical exercise has the potential to cause harm.However, the results of these exercise studies, at minimum, show that exercise can attenuate muscle damage due to disease, inactivity and steroid use. They reflect the benefit of exercise through the strengthening of complement (non-diseased) muscles, and should encourage further studies to confirm whether diseased muscle may experience regeneration. The definition of improvement must be established, and reproducible longitudinal studies must be conducted to determine the efficacy of exercise as therapy for IIM.