Steroid myopathy in connective tissue disease

Laboratory testing in the diagnosis and management of idiopathic inflammatory myopathies

Laboratory testing commonly used to assess the idiopathic inflammatory myopathies (IIMs) can be divided into three categories: (1) measurement of serum activities or concentrations of muscle-derived factors--such as enzymes, myoglobin, and other molecules--in order to assess muscle injury; (2) immunologic tests that detect markers of the disease process, including serum autoantibodies that have been associated with myositis; and (3) general laboratory tests that are used to assess the patient's general status and medical condition. The laboratory assessment of muscle-derived factors that reflect muscle injury, and the determination of serum autoantibodies, play valuable roles in the diagnosis and management of the IIM. Enzyme elevations do not correlate with disease activity in all patients, however, and they must be interpreted within the clinical context. Autoantibodies can identify disease subsets with distinctive patterns of clinical manifestations, genetics, responses to therapy and prognosis, but disease-specific autoantibodies are present in only half of patients with IIM. Recent studies have defined additional myositis autoantibodies that may improve our capacity to diagnose and manage the IIM.

Steroid myopathy: pathogenesis and effects of growth hormone and insulin-like growth factor-I administration

Glucocorticoids have been widely used in the treatment of autoimmune and other diseases. Chronic steroid use, however, could cause proximal muscle weakness and atrophy, termed steroid myopathy. The onset of steroid myopathy is usually insidious and there are no specific laboratory findings except for elevated urinary creatine excretion. Muscle biopsy reveals non-specific type II fiber atrophy. There are many reports showing preventive effects of either growth hormone (GH) or insulin-like growth factor (IGF)-I on steroid myopathy. The pathogenesis of steroid myopathy is not fully understood. Recently, glutamine synthetase has been reported to play a key role in steroid myopathy. GH as well as IGF-I decreased the steroid-induced glutamine synthetase activity in skeletal muscle.

Corticosteroids in Crohn's disease

Crohn's disease is a lifelong illness characterized by chronic recurrent flares. The precise etiology of Crohn's disease is unknown. However, it appears to involve an enhanced systemic immune response and intensified local intestinal mucosal inflammatory activity, mediated through various inflammatory cells and an array of proinflammatory cytokines. Corticosteroids have been the mainstay of treatment of Crohn's disease. The controlled trials of the National Cooperative Crohn's Disease Study and the European Cooperative Crohn's Disease Study established that corticosteroids were effective for the induction of remission in Crohn's disease for the duration of the studies (6-17 wk). However, corticosteroids have not been shown to have an impact on the maintenance of long term remission in patients with Crohn's disease. In addition, they are associated with a high potential for dependence and serious toxic side effects. Alternative classes of medical therapy for Crohn's disease, including modified corticosteroids and a group of new biological therapies, have proven to be efficacious in the management of active and/or quiescent Crohn's disease.

Neuromuscular manifestations of endocrine disorders

This article reviews the neuromuscular disorders associated with many endocrine disturbances. The severity of neuromuscular disorders varies. Some of these disturbances are mild, and others are severe and life threatening.

Osteoporosis in murine systemic lupus erythematosus--a laboratory model

The aim of this study was to assess the skeletal metabolism in a murine model of systemic lupus erythematosus (SLE). MRL/n and MRL/l mice (respectively representing a benign and a malignant form of the disease) were observed from 1.5 to 6.5 months of life. The monthly follow-up included: biochemical and histomorphometrical studies of the femoral bone, serum biochemistry, immunoglobulins and osteocalcin, and histological evaluation of the kidney tissue. The results showed a higher femoral weight (+11.5%), calcium (+4.4%) and protein bone content (+11.4%) and a significantly higher (+77%) phosphorus bone content in the MRL/n group; significantly lower (-48.9%) bone alkaline phosphatase enzymatic activity, lower bone alkaline/acid phosphatase enzymatic activities ratio (-40.8%) and lower (-38.4%) serum osteocalcin values in the MRL/l group (which might suggest reduced bone formation in these animals); markedly smaller trabecular bone volume (BV/TV) in the femoral head (-36.2%) and femoral neck (-39.8%), and smaller cortical and femoral areas in the mid-femoral shaft (-38.8% and -38.1% respectively) in the MRL/l group; higher serum immunoglobulins, increased serum blood urea nitrogen (BUN) and creatinine and a higher index of activity in the kidney histology in the MRL/l group, indicating increased activity of the disease in this substrain. The MRL mice, through their two substrains, may serve as a valuable laboratory animal model for study of the skeletal changes in SLE and of the influence of the disease activity on the skeletal metabolism.

The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats

The ability of the growth hormone secretagogue (GHS) Ipamorelin to counteract the catabolic effects of glucocorticoid (GC) on skeletal muscles and bone was investigated in vivo in an adult rat model. Groups of 8-month-old female rats were injected subcutaneously for 3 months with GC (methylprednisolone) 9 mg/kg/day or GHS (Ipamorelin) 100 microg/kg three times daily, or both GC and GHS in combination. The maximum tetanic tension of the calf muscles was determined in vivo in a materials testing machine. The maximum tetanic tension was increased significantly, and the periosteal bone formation rate increased four-fold in animals injected with GC and GHS in combination, compared with the group injected with GC alone. In conclusion, the decrease in muscle strength and bone formation found in GC-injected rats was counteracted by simultaneous administration of the growth hormone secretagogue.

Treatment of lupus with corticosteroids

Through direct signals to the nucleus mediated by the glucocorticoid receptor, exogenous glucocorticoids impact a broad array of cellular functions. DNA binding of the glucocorticoid receptor, depending upon the specific promoter to which the receptor binds, affects gene expression by recruiting transcription factors to the promoter or by interfering with the function of co-factors required for gene transcription. Steroid effects on the adhesion functions and release of products by phagocytic cells are prompt, occurring within hours of administration. Administration of corticosteroids results in rapid depletion of circulating T-cells due to a combination of effects including enhanced circulatory emigration, induction of apoptosis, inhibition of T-cell growth factors, and impaired release of cells from lymphoid tissues. Corticosteroid effects on B-cell function and immunoglobulin production are more delayed. The broad, generally suppressive effects of corticosteroids on the immune response render them useful for the management of most organ system manifestations of lupus. Corticosteroid toxicity in lupus is notable for greater susceptibility to infections, osteoporosis, osteonecrosis and accelerated atherogenesis. Although use of corticosteroids for patients with severe disease manifestations is associated with higher numbers of deaths from infections, overall survival appears to be improved.

Corticosteroid osteoporosis

Corticosteroids are widely used and effective agents for the control of many inflammatory diseases, but corticosteroid osteoporosis is a common problem associated with their long term high dose use. Prevention of corticosteroid osteoporosis is preferable to treatment of established corticosteroid bone loss. Several large double-blind controlled clinical trials in patients with corticosteroid osteoporosis have recently been published that provide new insights into its treatment. Based upon available evidence, the rank order of choice for prophylaxis would be a bisphosphonate followed by a vitamin D metabolite or an oestrogen type medication. Calcium alone appears to be unable to prevent rapid bone loss in patients starting corticosteroids, especially with prednisolone doses at 10 mg a day or greater. If an active vitamin D metabolite is used, calcium supplementation should be avoided unless dietary calcium intake is low. Hormone replacement therapy should be considered if hypogonadism is present. Since vertebral fracture is a common and important complication of high dose corticosteroid therapy, these findings suggest that rapid bone loss and hence fractures, can be prevented by prophylactic treatment. Although the follow-up data is limited, it is likely that such therapy needs to be continued beyond 12 months whilst patients continue significant doses of corticosteroid therapy.

Creatine kinase revisited

Creatine kinase (CK) is the single most important biochemical test in the evaluation of patients with myopathies. In health, serum CK concentration is higher in men, blacks, muscular individuals, and athletes. Idiopathic hyperCKemia is an entity restricted to asymptomatic patients with a negative family history for a neuromuscular disease acid normal neurological, electrodiagnostic. and histologic examinations. Serum CK concentration in myopathy correlates with seventy of illness, course of disease, available muscle mass, and myofiber necrosis. CK may be elevated in neurogenic disorders, particularly in Kennedy's disease and type III spinal muscular atrophy.

An update on glucocorticoid-induced osteoporosis

In general, bone loss from glucocorticoid treatment occurs rapidly within the first 6 months of therapy. Glucocorticoids alter bone metabolism by multiple pathways; however, the bone loss is greatest in areas rich in trabecular bone. Preventive measures should be initiated early. It is the author's opinion that all subjects initiating treatment with prednisone at 7.5 mg or greater require calcium supplementation (diet plus supplement) at a dose of 1500 mg and vitamin D at a dose of 400 to 800 IU/d. If the patient is going to remain on this dose of glucocorticoid for more than 4 weeks, an antiresorptive agent should be started (e.g., estrogen, bisphosphonate, raloxifene). If a patient has established osteoporosis and is either initiating glucocorticoid therapy or is chronically treated with prednisone at 5 mg d or greater in addition to calcium and vitamin D supplementation, a potent antiresorptive agent (bisphosphonate) should be started. A bone mineral density measurement of either the lumbar spine or the hip may be helpful is assessing an individual's risk of osteoporosis, may improve compliance with treatment, and can be used to monitor the efficacy of the prescribed therapy. There is no reason to withhold treatment for glucocorticoid-induced bone loss until a bone mass measurement is taken, however. In motivated patients, a weight-bearing and resistance exercise program should be prescribed to help retain muscle strength and prevent depression. If hypercalciuria develops with glucocorticoid use, either thiazide diuretics or sodium restriction may be helpful. In patients who continue to lose bone or experience fracture's despite antiresorptive therapy while on glucocorticoids, bone-building anabolic agents (e.g., hPTH 1-34 or PTH 1-84) may be available someday soon.

Corticosteroids in chronic obstructive pulmonary disease. Clinical benefits and risks

The use of systemic and inhaled corticosteroids for COPD has increased appreciably over the past 20 years. Clearer indications for corticosteroid therapy in COPD are beginning to emerge as the results from large clinical trials become available. Systemic corticosteroids are only modestly effective for acute COPD exacerbations, increase the risk for hyperglycemia, and should be given for no more than 2 weeks. The efficacy of long-term systemic corticosteroid therapy has not been adequately evaluated in this patient population. If longer term use of systemic steroids in COPD should be found to be useful, this conclusion would have to be weighed against the risk for serious adverse effects. High doses of inhaled corticosteroids cause a small sustained increase of the FEV1 in patients with mild and moderately severe COPD, but they do not slow the rate of FEV1 decline. Based on analyses of secondary outcome, inhaled corticosteroids may improve the respiratory symptoms and decrease the number and severity of COPD exacerbations in patients with more advanced disease. Low doses of inhaled corticosteroids appear to be safe, but there is growing awareness that higher doses may not be so benign.

Myopathies in the elderly

Muscle disease symptoms and myopathies are not uncommon in the elderly. Inflammatory and noninflammatory myopathies lead to proximal extremity or axial weakness and are superimposed on the intrinsic changes that occur in muscle with aging (sarcopenia). This article surveys the more common myopathies in the elderly based on a review of the process of sarcopenia, and how these age-related changes in muscle structure and function affect the results of the standard assessments of muscle disease in the elderly.

Juvenile idiopathic inflammatory myopathies: the value of magnetic resonance imaging in the detection of muscle involvement

CONTEXT

One of the major current challenges related to juvenile idiopathic inflammatory myopathy is the search for highly sensitive and specific non-invasive methods for diagnosis as well as for follow-up.

OBJECTIVES

The aim of our study was to describe typical magnetic resonance imaging findings and to investigate the usefulness of this method in detecting active muscle disease in juvenile dermatomyositis and juvenile systemic lupus erythematosus patients.

DESIGN

Transverse study, blinded assessment.

SETTING

University referral unit (Pediatric Rheumatology section, Department of Pediatrics, Universidade Federal de São Paulo / Escola Paulista de Medicina).

SAMPLE

Thirteen patients (9 girls) with dermatomyositis, as well as 13 patients (12 girls) with juvenile systemic lupus erythematosus and 10 normal children (5 girls), were enrolled in the study.

MAIN MEASUREMENTS

Qualitative and quantitative analyses of gluteus maximus, quadriceps, adductors and flexors were performed and evaluated by two radiologists, blinded to all clinical information. Spin-echo in T1, DP, T2 and IR was used in all MRI images.

RESULTS

The different muscle groups presented non-uniform involvement in the patients. The patients with dermatomyositis presented acute and chronic muscular alterations, while those with lupus presented only chronic myopathy, especially atrophy. In the dermatomyositis group, the major alterations were found in the gluteus and flexor regions (signal intensity and fat replacement). The signal intensity was increased in all acute myopathies.

CONCLUSION

The qualitative and quantitative resonance analyses are useful in detecting clinically active disease in patients with dermatomyositis.

Endocrine myopathies

This article provides a review of some of the muscular disorders that can arise from some of the commonly seen endocrinologic disturbances. Thyroid, parathyroid, and adrenal dysfunctions as they relate to neuromuscular symptoms are discussed. Common clinical presentations of the endocrine myopathies are highlighted, along with diagnostic evaluation and treatments.

Glucocorticoid-Induced Muscle Atrophy: Mechanisms And Therapeutic Strategies

OBJECTIVE

To analyze the mechanisms of action of glucocorticoids in causing muscle atrophy and to examine the therapeutic effect of testosterone as well as other treatment modalities in counteracting this adverse effect.

METHODS

We reviewed selected publications to analyze the mechanisms of glucocorticoid-induced muscle atrophy in animal models and in humans. The pathophysiologic features of glucocorticoid-induced hypogonadism and the possible relationship to the muscle atrophy in patients receiving glucocorticoids were assessed. The beneficial effects of testosterone on the muscles of hypogonadal and eugonadal men were also reviewed. Other measures such as exercise and glutamine and their possible therapeutic and preventive effects were examined in the context of hypercortisolemia.

RESULTS

Glucocorticoids induce rapid muscle breakdown and proximal muscle atrophy. The mechanism of glucocorticoid-induced muscle atrophy relies on the degradation of the myosin heavy chain (catabolic effect), the most important contractile protein in muscle, associated with a decrease of its synthesis (antianabolic effect). One of the contributing factors in the development of muscle atrophy is hypogonadism that is induced by long-term glucocorticoid use. Androgen possesses anabolic and anticatabolic effects in vitro and in animal models. Androgens can be used safely to counteract the catabolic effects of cortisol. Other measures such as exercise, glutamine, and alanyl-glutamine are promising in animal models of glucocorticoid-induced muscle atrophy.

CONCLUSION

This study suggests the possible efficacy of testosterone and glutamine on glucocorticoid-induced muscle atrophy. Testosterone and glutamine are natural biologic products with safe pharmacologic profiles, and their bioefficacy merits active research in humans.

Early deaths with thrombolytic therapy for acute myocardial infarction in corticosteroid-dependent rheumatoid arthritis

Intravenous thrombolytic therapy has become standard treatment for acute myocardial infarction (AMI). We describe three patients with long-standing seropositive rheumatoid arthritis (RA) on chronic corticosteroid therapy who experienced very early (1-6 h) mortality after the use of intravenous thrombolytic therapy for the treatment of AMI. All three patients likely experienced electromechanical dissociation (EMD). Their charts were evaluated in depth, and the literature was reviewed in regard to possible etiopathologic mechanisms. Within 1-6 h of apparently successful thrombolytic therapy for AMI, these three patients experienced sudden and profound bradycardia and hypotension and could not be resuscitated. The potential occurrence of EMD in all three patients raises the possibility of accelerated myocardial rupture, as EMD is one of the clinical hallmarks of this condition. As suggested by the three clustered cases, this heretofore undescribed association between sudden unexpected cardiac death and thrombolytic therapy for AMI in patients with seropositive, corticosteroid-dependent RA suggests that further study and observation are needed. This deleterious association, if verified, has important implications for the treatment of AMI in patients who have RA and are corticosteroid dependent.

Prevention and treatment of adverse effects of corticosteroids in systemic lupus erythematosus

Corticosteroid therapy has had a major impact on improvement in disease activity and long-term survival in patients with systemic lupus erythematosus (SLE). Unfortunately, the therapeutic advantages are accompanied by many manifestations of toxicity, some of which are short term and potentially reversible, while others cause chronic irreversible damage. Many of these features of toxicity have similar presentations to manifestations of SLE disease activity, and must be distinguished in the individual patient. The features of corticosteroid toxicity are reviewed in this chapter, and means of prevention and/or treatment are discussed.

The science and therapy of glucocorticoid-induced bone loss

Glucocorticoids are critical in the management of chronic, noninfectious, inflammatory diseases. Bone loss is a most devastating side effect of these powerful medications. Glucocorticoids produce bone loss by altering calcium metabolism, suppressing gonadal hormone production, and inhibiting bone formation. Now that the mechanism of glucocorticoid-induced bone loss is understood and effective medications are available, this disease can be prevented and reversed.

Management of complications of glucocorticoid therapy

Corticosteroids are commonly employed in the treatment of a wide variety of pulmonary disorders, including asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, sarcoidosis, and pulmonary vasculitides; as well as in the lung transplant population. Frequently, steroid-induced complications contribute significantly to morbidity and diminished quality of life, often overshadowing the impact of the underlying lung disease. This article will discuss the more commonly encountered complications of corticosteroids in the context of the method of delivery, events occurring with chronic use, and events related to withdrawal.

Endocrine neuromyopathies

The myopathies associated with endocrine disorders range in clinical presentation from the relatively nonspecific pattern of proximal muscle weakness of glucocorticoid excess states to specific presentations of contractions produced in tetany. All endocrine neuromyopathies emphasize the role of skeletal muscle in protein, carbohydrate, and electrolyte metabolism. Hormonal abnormalities tend to compromise muscle force generation by indirect effects on muscle function. The recognition and effective treatment of all these disorders require the identification of the underlying hormonal imbalances and awareness of general medical problems produced by the endocrine disorders.

Toxic myopathies

Toxic myopathies may occur with a variety of prescribed medications, illicit drug abuse, or other toxins. The article discusses an overview of some of the compounds that may cause myopathy, the clinical and laboratory features, histology, mechanisms of action, and potential risk factors of myopathy. The ability to recognize these syndromes is essential to avoid unnecessary tests and to avoid delay in treatment, especially in critically ill patients or patients with other neuromuscular diseases.

Adverse effects of corticosteroid therapy for COPD. A critical review

Inhaled and systemic corticosteroids are commonly prescribed for the treatment of COPD. Despite their frequent use, there is insufficient evidence regarding efficacy of steroid therapy in COPD. While awaiting the results of more definitive prospective trials, the clinician must evaluate whether the benefits of such therapy outweigh the potential for adverse events. This is particularly pertinent in the population of patients with COPD who generally are older, less active, and have significant tobacco use histories, all of which may place them at greater risk for adverse effects. In this review, we examine the current scientific evidence supporting the many purported adverse systemic effects associated with the use of corticosteroids in the treatment of COPD.

Safety of corticosteroids and immunosuppressive agents in ulcerative colitis

For many years, corticosteroids have been the mainstay for treating acute ulcerative colitis. In patients with refractory disease, immunosuppressive therapy may be indicated, including azathioprine or its metabolite 6-mercaptopurine, cyclosporin and possibly methotrexate. Their benefits in ulcerative colitis must be weighed up against their possible adverse effects, the availability of surgical cure for this condition, and the long-term risk of carcinoma complicating colitis that applies in patients with chronic extensive disease. Information about the safety of corticosteroids and immunosuppressive agents has accumulated as a result of their extensive use in inflammatory bowel disease, organ transplantation and various other disorders.

Glucocorticoid-induced muscle atrophy. The role of exercise in treatment and prevention

Glucocorticoids have catabolic effects on skeletal muscle. These effects demonstrate fiber type specificity: Type IIB fibers are most susceptible and type I fibers least susceptible to the atrophy effects of glucocorticoids. Exercise training has been used frequently to counteract glucocorticoid-induced muscle atrophy. Studies have demonstrated that both resistance exercise and endurance exercise are effective in attenuating this atrophy. The cellular mechanisms mediating the attenuating effect of exercise on glucocorticoid-induced atrophy are not completely understood. More research is needed to further elucidate the details of these mechanisms and to determine the most efficacious exercise protocols for deterring glucocorticoid-induced muscle atrophy. Exercise evaluation of patients with glucocorticoid-induced myopathy and subsequent exercise prescription must be individualized and based on the patient's initial muscle function and medical status.

Muscle involvement in rheumatoid arthritis: clinicopathological study of 21 symptomatic cases

The aim of the current study was to analyze the frequency and characteristics of symptomatic myopathies occurring in rheumatoid arthritis (RA) patients, to correlate these findings with clinical data, and to evaluate their therapeutic implications. All RA patients from a cohort of 350 RA patients from a single institution who developed muscular symptomatology during an 8-year period were included in the study (n = 21). Clinical and laboratory data and electromyographic results were recorded in all cases, and an open muscle biopsy was performed. Weakness and muscle atrophy were the most common symptoms. Serum creatine kinase was increased in 8 cases (38%). Histopathologic study showed type 2 atrophy in 12 cases. In 13 cases, a treatable disease was diagnosed: dermatomyositis (n = 2), d-penicillamine-related dermatomyositis (n = 2), polymyositis (n = 1), muscular mononuclear cell infiltration (n = 3), polyarteritis nodosa (n = 1), glucocorticoid myopathy (n = 3), and toxic chloroquine myopathy (n = 1). In all but 1 patient, muscular clinical response to new therapy and/or drug withdrawal was satisfactory. Although symptomatic muscular involvement in RA is low (6% in the current series), we have found that nearly two thirds of cases were caused by potentially treatable conditions, mainly myositis or toxic myopathies.

[Present status of cortisone myopathy]

Steroid myopathy is one of the various side effects of prolonged treatments, particularly with the 9 alpha fluorinated steroids. The receptor protein probably plays a major role with a decrease in protein synthesis. There is no mean to detect this myopathy before clinical signs appear. Neither muscular testing nor enzymes nor electromyography give arguments and muscular biopsy is aggressive. Low density scanner and MNR could help diagnosis. Frequency of disease is not known. A total cumulative maintenance steroid dosage of 400 mg can be sufficient. Proximal muscles are usually involved, quadriceps and other pelvic girdle muscles being more severely affected. Fast twitch glycolytic type IIB fibers are particularly susceptible. Physical exercise is effective in preventing myopathy. Nevertheless, no special rehabilitation program has been tested for the moment in human beings.

Neuromuscular disease: rehabilitation and electrodiagnosis. 3. Muscle disease

The purpose of this section of the Self-Directed Physiatric Education Program Study Guide on rehabilitation in diseases affecting nerve and muscle is to assist practitioners and trainees in physical medicine and rehabilitation by providing practical information about inherited and acquired muscle diseases. It emphasizes clinical management issues and new developments in commonly encountered muscle disorders.

Laboratory evaluation of the inflammatory myopathies

The laboratory plays an important role in the diagnosis, evaluation, and classification of the heterogeneous group of diseases known as the IIM, which are characterized by chronic muscle inflammation. Serial measurements of the levels of muscle-derived enzymes in serum are the traditional laboratory studies used to follow the clinical course of patients with IIM, although other laboratory tests can also be useful in assessing myositis disease activity. Several markers of immune system activation, including cytokines and lymphocyte markers, show promise as possibly more sensitive measures of myositis disease activity. Discovery of a unique group of MSAs over the past decade has provided an immunologic basis for defining relatively homogeneous subsets of patients who share similar clinical features, disease courses, and responses to therapy. Future investigations of novel immunologic activation markers, as well as the cloning and expression of target autoantigens of the MSAs, should allow better diagnostic assays, enhanced prognosis, and a better understanding of the pathogenesis of these disorders.

The risks and benefits of corticosteroids in advanced cancer

Corticosteroids are extensively prescribed in advanced cancer for various specific indications (e.g. spinal cord compression), for pain relief, as hormone therapy and to stimulate appetite and wellbeing. Choice of corticosteroid is dictated largely by local fashion, and times of administration are more traditional than pharmacological. Corticosteroids have many potential disadvantages, some life-threatening (e.g. masked septicaemia). Others are seriously debilitating (e.g. myopathy, avascular bone necrosis). Oropharyngeal candidiasis is a common complication. Corticosteroids are withdrawn in about 5% of patients because of unacceptable adverse effects, including moon-face and diabetes mellitus. Corticosteroid hypersensitivity occurs, and the succinate salts have been associated with bronchospasm. Steroid pseudorheumatism may occur with high dose therapy or when tailing off after a prolonged course. Important drug interactions with corticosteroids relate to salt and water retention, and decreased glucose tolerance. Some anticonvulsants cause an increased clearance of corticosteroids and, with dexamethasone, up to a 50% reduction in the anticipated effect. The benefit of corticosteroids in terms of increased appetite, mood and activity has been demonstrated in several controlled trials. The effect may well be time-limited in most patients. In several studies, corticosteroids have resulted in an analgesic-sparing effect. Some centres use very high doses of dexamethasone in cases of spinal cord compression, although the justification for these is not obvious. Corticosteroids are used to help relieve nerve compression pain and in symptomatic raised intracranial pressure. Corticosteroids are also injected locally into or around bone metastases, particularly ribs and the sacro-iliac joints. Epidural injections are used for patients with troublesome intractable low back pain. Corticosteroids are now used less often in hypercalcaemia because of poor response rates. More benefit is obtained, however, if high dosages are used, e.g. prednisolone 60 to 80 mg/day. Dexamethasone is widely used as an antiemetic in association with chemotherapy. Some centres use dexamethasone by continuous subcutaneous infusion in selected patients when the oral route is not feasible. The choice of starting dose of a corticosteroid is largely arbitrary. It is important, however, not to miss a possible treatment benefit by prescribing too low a dose. For most patients, an initial dosage of prednisolone of 30 to 60 mg/day (dexamethasone 4 to 8 mg/day) is appropriate. In patients with anorexia, there are several alternative options that should be considered. There is evidence to suggest that patients with advanced cancer receiving a corticosteroid are not as closely monitored as other patients. There is a need to state clearly in writing the reason(s) for prescription and to review after 1 or 2 weeks.(ABSTRACT TRUNCATED AT 400 WORDS)

Neuromuscular disorder in intensive care unit patients treated with pancuronium bromide. Occurrence in a cluster group of seven patients and two sporadic cases, with electrophysiologic and histologic examination

During six consecutive months, seven patients admitted to our ICU (15 beds, general ICU, approximately 300 intubated patients per year) for acute respiratory failure requiring intubation and mechanical ventilation presented with a peculiar neuromuscular disorder. After the occurrence of this cluster group of patients, we detected two more similar but isolated cases in the following 18 months, ie, altogether 9 patients in 2 years of observation, or 1.55 percent of all intubated patients in our ICU. Sedation was achieved using midazolam, curarization was effected with the neuromuscular non-depolarizing agent pancuronium bromide (PB), and corticosteroids were administered to eight patients. Shortly after discontinuation of sedation and curarization, we observed a persistent tetraparetic syndrome and/or peroneal palsy with a concomitant increase of serum creatine kinase (CK). None of the patients was septic or had the multisystem organ failure. A strong association between CK increase and PB administration was found, whereas no patient suffered severe liver or kidney failure. The duration of the neurologic deficit ranged from 4 to 52 weeks, with only partial recovery for some patients; the duration of dysfunction was apparently related to the total dose of corticosteroids received. Two patients had difficulty being weaned from the respirator and required tracheostomy. Electrophysiologic studies showed signs of axonal neuropathy and myopathic changes, ie, motor units of brief duration, small amplitude, overly abundant for the voluntary effort being exerted. Muscle biopsies showed significant myopathic alterations, with foci of muscle necrosis in most patients and minimal lymphocytic inflammation in one patient. The neurologic complication described differs from the polyneuropathy in critically ill patients. Furthermore, PB or corticosteroids or both appear to be the causal agents. The duration of the neuromuscular dysfunction may be related to concomitant steroid therapy. The CK enzyme seems to be a marker of the disorder. This disorder is associated with myopathic alterations and axonal degeneration in some patients. Pancuronium bromide should be used with caution, particularly when associated with steroids therapy, and it may cause difficulty in weaning patients from the respirator.

Proximal muscle weakness in a patient with hepatocellular carcinoma

Asthenia and generalized weakness are common in cancer patients. There are multiple causes for these symptoms. We describe a case of rapid onset of proximal muscle weakness in a patient with hepatocellular carcinoma. The differential diagnosis of muscle weakness in the palliative care patient is reviewed. The discussion centers on steroid myopathy and its treatment.

Turnover of skeletal muscle contractile proteins in glucocorticoid myopathy

Muscle weakness in glucocorticoid myopathy results mainly from muscle atrophy, the reason for which is the accelerated catabolism of muscle proteins. As the content of lysosomes in skeletal muscle, particularly in fast-twitch glycolytic fibers, is relatively low the non-lysosomal pathway makes a particularly significant contribution and has special importance in the initial rate-limiting steps in the catabolism of contractile proteins and in the regulation of their turnover rate. The turnover rate of actin and the myosin heavy chain is decreased in all types of muscle fibers, and more rapid turnover of the myosin light chain is registered in the fast-twitch glycolytic and oxidative-glycolytic fibers. Exercise and simultaneous glucocorticoid treatment is an effective measure in retarding skeletal muscle atrophy and provides protection against muscle wasting.

Lupus nephritis in childhood and adolescence

Lupus nephritis in childhood usually presents after the age of 10 years, and presentation under 5 years is very rare. More males (F:M ratio 4.5:1) are affected than in adult-onset cases, but the ratio is the same in prepubertal and pubertal children. The incidence of clinically evident renal disease is greater at onset than in adults (82%), the usual presentation being with proteinuria, 50% having a nephrotic syndrome. Half the children show World Health Organisation class IV nephritis in renal biopsies. Neuropsychiatric lupus is present at onset in 30%, may complicate 50% at some point and remains a major problem. Prognosis has improved greatly over the past 30 years, at least in part the result of immunosuppressive treatment. Treatment of the initial phase may be guided by the severity of the renal biopsy appearances, more aggressive treatment including cytotoxic agents, i.v. methylprednisolone and perhaps plasma exchange, although the value of exchange is not established. Controversy persists as to the most effective cytotoxic treatment in the acute phase, both oral and i.v. cyclophosphamide and azathioprine being used in different units. In the chronic maintenance phase it seems established both clinically and histologically that addition of a cytotoxic agent improves outcome, but again the drug and route of administration are contentious. Azathioprine has the advantage of being safe for pregnancy and not gonadotoxic, whilst i.v. cyclophosphamide has been demonstrated to improve results over prednisolone alone in controlled trials and has advantages in non-compliant patients. No trial comparing the two regimes has been carried out, and one is needed. Today children much less commonly go into renal failure, and the main causes of actual death (15% of patients over 10 years) are now infections and extra-renal manifestations of lupus, principally neurological. Morbidity of the disease and the treatment remain a major problem, especially when treatment exacerbates complications of the disease itself, such as infections, osteonecrosis, thrombosis, vascular disease and possibly neoplasia.

Leucine metabolism in patients with Cushing's syndrome before and after successful treatment

OBJECTIVE

Results from studies on the effect of glucocorticosteroids on protein turnover in both rat and man have been conflicting. The aim of this study was to investigate the primary cause of muscle wasting in patients with Cushing's syndrome.

DESIGN

Studies of whole body 1(-14)C-leucine turnover in patients with Cushing's syndrome before and after successful treatment, and in control subjects.

PATIENTS

Eleven patients with Cushing's syndrome before and after (n = 5) treatment and 11 control subjects.

MEASUREMENTS

Whole body 1(-14)C-leucine turnover to determine leucine metabolic clearance rate, leucine production rate, leucine oxidation rate and leucine incorporation into protein.

RESULTS

Plasma leucine concentration (mean +/- SEM 100 +/- 6 mumol/l), leucine metabolic clearance rate (9.97 +/- 0.11 mumol/min/kg), leucine turnover (0.98 +/- 0.11 mumol/min/kg) and leucine incorporation into protein (0.71 +/- 0.09 mumol/min/kg) were all significantly reduced in patients with Cushing's syndrome compared with control subjects (122 +/- 6 mumol/l, P < 0.05; 13.61 +/- 1.27 mumol/min/kg, P < 0.05; 1.65 +/- 0.12 mumol/min/kg, P < 0.05; 1.46 +/- 0.10 mumol/min/kg, P < 0.001, respectively). Leucine oxidation rate was similar in the patients with Cushing's syndrome and control subjects. When leucine metabolism was expressed in terms of lean body mass (LBM) in five patients with Cushing's syndrome and 11 control subjects, leucine MCR, leucine turnover and leucine oxidation were not significantly different in the two groups. However, leucine incorporation into protein was significantly reduced (P < 0.001) in the patients with Cushing's syndrome (1.07 +/- 0.20 mumol/min/kg LBM) compared with control subjects (1.95 +/- 0.11 mumol/min/kg LBM).

CONCLUSION

We conclude from these studies that the muscle wasting associated with Cushing's syndrome is primarily due to a reduction in protein synthesis.

Bed rest during pregnancy: implications for nursing

Research on nonpregnant individuals reveals that bed rest produces numerous adverse physical and psychosocial effects. Evidence shows that bed rest affects pregnant women in the same manner. This article provides an overview of the history of bed rest, research on the side effects of bed rest, and a discussion of the research that has been conducted on these side effects during pregnancy. Also discussed are implications for providing antepartum, intrapartum, and postpartum nursing care.

Triamcinolone and prednisolone affect contractile properties and histopathology of rat diaphragm differently

Diaphragm atrophy and weakness occur after administration of massive doses of corticosteroids for short periods. In the present study the effects of prolonged administration of moderate doses of fluorinated and nonfluorinated steroids were investigated on contractile properties and histopathology of rat diaphragm. 60 rats received saline, 1.0 mg/kg triamcinolone, or 1.25 or 5 mg/kg i.m. prednisolone daily for 4 wk. Respiratory and peripheral muscle mass increased similarly in control and both prednisolone groups, whereas triamcinolone caused severe muscle wasting. Maximal tetanic tension averaged 2.23 +/- 0.54 kg/cm2 (SD) in the control group. An increased number of diaphragmatic bundles in the 5-mg/kg prednisolone group generated maximal tetanic tensions < 2.0 kg/cm2 (P < 0.05). In addition, fatigability during the force-frequency protocol was most pronounced in this group (P < 0.05). In contrast, triamcinolone caused a prolonged half-relaxation time and a leftward shift of the force-frequency curve (P < 0.05). Histological examination of the diaphragm showed a normal pattern in the control and 1.25-mg/kg prednisolone group. Myogenic changes, however, were found in the 5-mg/kg prednisolone group and, more pronounced, in the triamcinolone group. Selective type IIb fiber atrophy was found in the latter group, but not in the prednisolone groups. In conclusion, triamcinolone induced type IIb fiber atrophy, resulting in reduced respiratory muscle strength and a leftward shift of the force-frequency curve. In contrast, 5 mg/kg prednisolone caused alterations in diaphragmatic contractile properties and histological changes without fiber atrophy.

Exercise capacity and hemodynamics in systemic lupus erythematosus: a Doppler echocardiographic exercise study

Although pulmonary hypertension is a well-described manifestation of systemic lupus erythematosus, there are few data regarding the pulmonary artery pressure response to exercise. We hypothesized that exercise capacity was reduced and that the pulmonary artery pressure response to exercise was abnormal in patients with systemic lupus erythematosus. To test these hypotheses, we performed Doppler exercise echocardiography in 18 patients with lupus and 10 normal control subjects. Exercise duration was significantly reduced in the patients with lupus (8.1 vs 14.4 minutes for control subjects, p < or = 0.001). Pulmonary artery pressure was significantly higher in the patients with lupus at rest and during the first two stages of exercise (p < 0.05). Cardiac indexes at rest were similar in the two groups, suggesting that increased pulmonary vascular resistance was the mechanism for the higher pulmonary pressure we observed. We conclude that abnormal exercise hemodynamics may contribute to reduced exercise capacity in patients with lupus.

Prevention and treatment of glucocorticoid-induced osteoporosis. A pathogenetic perspective

Since the discovery of cortisol and the synthesis of related compounds, these potent pharmacologic agents have been progressively more widely utilized in allergic, pulmonary, and rheumatologic conditions. Organ transplantation represents a new group of patients added to the already large pool of subjects receiving glucocorticoids. However, glucocorticoids cause major side effects involving several organ systems, including the cardiovascular, endocrine, gastrointestinal, ophthalmologic, and musculoskeletal systems. Among the most dramatic side effects is the development of glucocorticoid-induced osteoporosis. Glucocorticoid use in the treatment of chronic obstructive pulmonary disease accounts for the majority of male patients with osteoporosis seen in our mineral metabolism clinic. This article focuses on glucocorticoid-induced osteoporosis in the adult with an emphasis on the clinical aspects of this condition. It is intended not as an extensive review on the subject but as a practical guide to help clinicians prevent and treat this condition in adult patients.

Serial magnetic resonance imaging in juvenile dermatomyositis

Magnetic resonance imaging (MRI) was used to follow the course of juvenile dermatomyositis from the onset of disease through resolution of a primary relapse. The signal intensity of the T2-weighted image of involved muscles was elevated during periods of disease activity, and returned to approximately normal levels with effective suppression of disease activity. T1-weighted images of involved muscles remained approximately normal despite disease activity.

[Cortisone-induced osteoporosis: from physiopathology to treatment]

Corticosteroid-induced osteoporosis, the principal cause of "secondary" osteoporosis, is usually observed in patients under prolonged systemic corticosteroid therapy and results from the multiple effects exerted by these drugs on bone cell metabolism. Corticosteroids reduce the intestinal absorption of calcium and its tubular reabsorption, thereby negativating the calcium balance and inducing a parathyroid reaction. This reaction is responsible for an increase in bone cell remodelling, but the main manifestation of the direct effect of corticosteroids on bone is osteoblast depression, so that there is disparity between bone resorption and formation, which in turn is responsible for bone tissue deficit. Sex hormone deficiency (due to menopause or treatment) and lack of physical activities (due to the causal disease or to iatrogenic myopathy) amplify bone rarefaction. By quantifying the bone loss, modern densitometry methods provide an early risk evaluation. Osteoporosis of varying intensity exposes some 20% of patients to fractures, vertebral collapse and rib fractures. Preventive measures are always recommended, including minimal effective dose corticosteroid therapy, sodium-free diet, calcium and vitamin D supplement, sex hormone replacement and pursuance of physical activities. Once the stage of fractures by osteoporosis has been reached, the "curative" treatment aims at reducing the incidence of new fractures, either by slowing down osteoclast resorption, or by restoring the bone tissue reserve through stimulation of the osteoblasts. The usefulness of these therapeutic measures in the preventive treatment of corticosteroid-induced osteoporosis remains controverted.