Corticosteroid-induced osteoporosis

Efficacy and safety of medical therapy for low bone mineral density in patients with inflammatory bowel disease: a meta-analysis and systematic review

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) are at risk for osteoporosis and fracture. However, the efficacy of medical treatments for osteoporosis in increasing bone mineral density (BMD) in patients with IBD has not been well characterized.

METHODS

We conducted a meta-analysis and systematic review of controlled trials to evaluate the efficacy and safety of medical therapies used for low BMD in patients with IBD (Crohn's disease, ulcerative colitis, or indeterminate colitis). We searched MEDLINE, EMBASE, Google scholar, the University Hospital Medical Information Network (UMIN) Clinical Trials Registry, and Cochrane Central Register of Controlled Trials for studies that assessed the efficacy of medical treatment for low BMD in patients with IBD. We also manually searched abstracts from scientific meetings and bibliographies of identified articles for additional references. The primary outcome assessed was changes in BMD at the lumbar spine. We also collected data on hip BMD, numbers of new fractures, and adverse effects. Data were pooled by using random-effects models and by mixed-effects analysis for primary aims, when subgroup analysis by individual drug was possible.

RESULTS

We analyzed data from 19 randomized controlled studies; 2 used calcium and vitamin D as therapies, 13 used bisphosphonates, 4 used fluoride, 1 used calcitonin, and 1 used low-impact exercise. The pooled effect of bisphosphonates was greater than that of controls in increasing BMD at the lumbar spine (standard difference in means, 0.51; 95% confidence interval, 0.29-0.72) and hip (standard difference in means, 0.26; 95% confidence interval, 0.04-0.49) with comparable tolerability, and the risk of vertebral fractures was reduced. Fluoride increased lumbar spine BMD, but its ability to reduce risk of fracture was unclear. There was no evidence that the other interventions increased BMD.

CONCLUSIONS

On the basis of a meta-analysis, bisphosphonate is effective and well tolerated for the treatment of low BMD in patients with IBD and reduces the risk of vertebral fractures. There are insufficient data to support the efficacy of calcium and vitamin D, fluoride, calcitonin, or low-impact exercise. However, the small number of randomized controlled trials limited our meta-analysis.

Immunosuppressant-related hip pain after orthotopic liver transplant

OBJECTIVES

Immunosuppressant-related hip pain can greatly affect a patient's mobility and increase the number of total hip arthroplasties. We investigated risk factors and causes of hip pain after orthotopic liver transplant.

MATERIALS AND METHODS

The medical records of 175 adult orthotopic liver transplant patients, who were followed-up for more than 2 years, were retrospectively reviewed. Data collected from the records included primary disease, medications, biochemical results, Child-Turcotte-Pugh score, death, rejection, and complications related to liver transplant.

RESULTS

A total of 11 patients (6.3%) complained of hip pain, which was diagnosed as calcineurin-inhibitor-induced pain syndrome in 4 patients (2.3%), osteonecrosis of the femoral head in 3 patients (1.7%), and osteoporosis in 2 patients (1.1%). The incidence of calcineurin-inhibitor-induced pain syndrome was related to the dosage of tacrolimus (P > .05) but independent of methylprednisolone use. The occurrence of osteonecrosis of the femoral head was independent of the dosage and early withdrawal of methylprednisolone (P > .05). Patients with methylprednisolone withdrawal within 6 months had significantly longer survival than those using methylprednisolone for more than 6 months (50 ± 15 vs 41 ± 18 mo; P = .007).

CONCLUSIONS

Calcineurin-inhibitor-induced pain syndrome and osteonecrosis of the femoral head are main causes of hip pain in adult orthotopic liver transplant patients. Osteonecrosis of the femoral head was not common, but the incidence of hip pain owing to calcineurin-inhibitor-induced pain syndrome was relatively high in orthotopic liver transplant patients. Early withdrawal of methylprednisolone could benefit the patients' survival.

High-throughput screening of a small molecule library for promoters and inhibitors of mesenchymal stem cell osteogenic differentiation

The use of high-throughput screening (HTS) techniques has long been employed by the pharmaceutical industry to increase discovery rates for new drugs that could be useful for disease treatment, yet this technology has only been minimally applied in other applications such as in tissue regeneration. In this work, an assay for the osteogenic differentiation of human mesenchymal stem cells (hMSCs) was developed and used to screen a library of small molecules for their potential as either promoters or inhibitors of osteogenesis, based on levels of alkaline phosphatase activity and cellular viability. From a library of 1,040 molecules, 36 promoters, and 20 inhibitors were identified as hits based on statistical criteria. Osteopromoters from this library were further investigated using standard culture techniques and a wider range of outcomes to verify that these compounds drive cellular differentiation. Several hits led to some improvement in the expression of alkaline phosphatase, osteogenic gene expression, and matrix mineralization by hMSCs when compared to the standard dexamethasone supplemented media and one molecule was investigated in combination with a recently identified biodegradable and osteoconductive polymer. This work illustrates the ability of HTS to more rapidly identify potential molecules to control stem cell differentiation.

Calcitonin and prednisolone display antagonistic actions on bone and have synergistic effects in experimental arthritis

We tested here the hypothesis that calcitonin and glucocorticoids, known to modulate bone metabolism, could have opposite actions on bone cells regulating expression of cytokine receptor activator of nuclear factor-kappaBeta ligand (RANKL) and osteoprotegerin (OPG). In the U2OS osteosarcoma cell line, calcitonin (10(-11) to 10(-9) mol/L) reduced RANKL and augmented OPG both at the mRNA and protein levels. Cell incubation with prednisolone (10(-8) to 10(-6) mol/L), the glucocorticoid chosen for this study, produced opposite results. These molecular studies prompted more functional analyses whereby osteoclast bone resorptive activity was determined. Calcitonin (10(-10) mol/L) abrogated the stimulating effect of 10 ng/ml RANKL or 10(-9) mol/L prednisolone; similar results were obtained with OPG. Assessment of calcitonin and prednisolone effects in an in vivo model of rheumatoid arthritis revealed partially surprising results. In fact, calcitonin not only preserved bone morphology (as assessed on day 18) in rats subjected to arthritis and treated with prednisolone (0.8 to 4 mg/kg daily from day 13) but also synergized with the steroid to elicit its antiarthritic effects. These results suggest that calcitonin could be used as a novel cotreatment to augment efficacy and reduce side effects associated with the prolonged use of steroids.

Balloon kyphoplasty for vertebral compression fractures in solid organ transplant recipients: results of treatment and comparison with primary osteoporotic vertebral compression fractures

BACKGROUND CONTEXT

Balloon kyphoplasty has become established as a useful treatment for vertebral compression fractures (VCF) associated with primary osteoporosis and osteolytic tumors. Organ transplant recipients are also at risk for VCF because of their underlying disease process and because they require long-term treatment with steroids and other immunosuppressive drugs.

PURPOSE

To explore whether balloon kyphoplasty is an effective treatment for VCF that develop in solid organ transplant recipients. A secondary goal was to determine whether there are any differences between VCF in transplant patients and VCF in patients with primary osteoporosis, with respect to disease severity and new fracture development.

STUDY DESIGN

Prospective, longitudinal clinical series.

PATIENT SAMPLE

The transplant group included 10 consecutive transplant patients (9 liver and 1 kidney), with a total of 29 symptomatic VCFs. The comparison group included 10 consecutive patients with primary osteoporosis and no history of organ transplantation, with a total of 15 VCFs.

OUTCOME MEASURES

The primary clinical end point was back pain, measured using the Visual Analog Scale (VAS), which was recorded at baseline, and 1 and 12 months postprocedure. Radiographic evaluation included measurement of Cobb angles for each treated vertebral segment on preprocedure and 1-month postprocedure lateral radiographs. An improvement of >5 degrees was considered significant. The number of fractures seen at the time of diagnosis and the number of new fractures occurring during the follow-up period were recorded.

METHODS

Balloon kyphoplasty was performed at all symptomatic levels. All fractures were treated within 3 months of onset. Patient follow-up was 12 months.

RESULTS

The transplant group had significantly higher levels of pain at baseline, (mean VAS 9.3 and 7.7 for the transplant group and primary osteoporosis group, respectively: p=.013). After treatment, the VAS decreased to 3.2 in the transplant group and 1.5 in the comparison group. Improvement was highly significant in both groups (p<.001), and was maintained at 12-month follow-up. Sagittal alignment was improved by >5 degrees in three patients in each group (30%). There were no procedural complications in either group. Compared with the primary osteoporosis group, the transplant group was more likely to have multiple fractures at the time of diagnosis (2.9 vs. 1.5, p=.03), had a twofold greater incidence of new fractures during the follow-up period (40% vs. 20%), was more than a decade younger (64 vs. 75 years, p<.01), was much more likely to have received chronic immunosuppressive therapy with glucocorticoids and calcineurin phosphate inhibitors (100% vs. 0%, p<.001), and had a higher percentage of males (70% vs. 10%, p=.02),

CONCLUSIONS

These data suggest that balloon kyphoplasty can be performed safely in organ transplant recipients with VCFs. The degree of pain relief is equivalent to that seen in patients with primary osteoporosis. Results are durable at 12-month follow-up. Transplant patients developed earlier and more severe bony disease, with more severe baseline pain, a higher incidence of multiple fractures at the time of diagnosis, and a greater risk of new fracture development posttreatment, as compared with the primary osteoporosis group.

Osteoporosis in Health and Disease: A Dermatologist's Perspective

Osteoporosis affects more than 75 million people in the United States, Asia, and Europe. Osteoporosis results from a combination of genetic and environmental factors that contribute to peak bone mass and the rate of bone loss. These factors include medications, diet, race, sex, lifestyle, and physical activity. The management of osteoporosis can be complicated by simultaneous treatment of other diseases. For dermatologists, the use of long-term oral corticosteroids for the management of immunobullous and blistering diseases is of particular importance. Although these treatment modalities are potentially lifesaving for patients, the side effects can be dangerous. This article examines the pathophysiology, clinical course, and treatments for osteoporosis and the special considerations that arise when managing patients using corticosteroids.

Hyperparathyroidism in dogs with hyperadrenocorticism

OBJECTIVES

To assess the effect of canine hyperadrenocorticism (HAC) on parathyroid hormone (PTH), phosphate and calcium concentrations.

METHODS

PTH concentrations and routine biochemical parameters were measured in 68 dogs with HAC. Ionised calcium was measured in 28 of these dogs. The results obtained were compared with an age- and weight-matched group of 20 hospital patients that did not show signs of HAC.

RESULTS

There were significant differences between the PTH, phosphate, alkaline phosphatase, creatinine and albumin concentrations between the two groups. Total and ionised calcium concentrations were not significantly different. Most of the dogs (92 per cent) with HAC had PTH concentrations that were greater than the reference range (10 to 60 pg/ml), and in 23 dogs they were greater than 180 pg/ml. There were significant positive correlations between the PTH and basal cortisol, post-adrenocorticotropic hormone (ACTH) cortisol and alkaline phosphatase concentrations, and also the phosphate and post-ACTH cortisol concentrations.

CLINICAL SIGNIFICANCE

Adrenal secondary hyperparathyroidism is a cause of increased PTH concentrations and may be associated with abnormalities in calcium and phosphate metabolism in dogs with HAC. The findings of this study could explain why canine HAC may cause clinical signs such as calcinosis cutis that are associated with altered calcium metabolism.

Histomorphometric analysis of glucocorticoid-induced osteoporosis

Bone histomorphometry or quantitative histology consists of counting or measuring tissue components: cells, extracellular constituents and microarchitecture. Bone histomorphometry is the only method that allows the measurement of mineralization rate and the study of bone formation at three levels: cell, remodeling unit and tissue levels. It is a useful tool to explain the pathogenesis and cellular mechanisms of different metabolic bone diseases such as glucocorticoid-induced osteoporosis (GIO). Glucocorticoids (GC) affect calcium and bone metabolism at every level, but the main effect is the osteoblastic dysfunction. Concerning the bone formation, some histomorphometric studies have shown a depressed osteoblastic activity at a cell, bone remodeling unit, and tissue levels. In addition, there is evidence of a shortening of the period in which the osteoblasts work actively forming the bone matrix. This latter effect seems to occur after high cumulative doses of GC. With regard to the resorption, the results are still debated, but histomorphometric parameters seem to be increased in the majority of studies, at least in the first period of the GC treatment. From a structural point of view, GC seem to induce a thinning of the trabeculae without their perforation, which occurs only after high cumulative doses. Anti-resorptive treatments, such as bisphosphonates, are able to counteract the negative effects of GC on bone. In particular, along with their active working period, they prolong the lifespan of osteoblasts and osteocytes. In addition, the anti-resorptive treatments seem to extend the time for secondary mineralization through a reduction of the Activation Frequency. The latter is an intriguing mechanism of bisphosphonates in GIO that needs further ad hoc investigations.

Recommendations for the Registration of Agents to be Used in the Prevention and Treatment of Glucocorticoid-Induced Osteoporosis: Updated Recommendations from the Group for the Respect of Ethics and Excellence in Science

OBJECTIVES

The Group for the Respect and Excellence in Science (GREES) has reviewed and updated their recommendations for clinical trials to evaluate the efficacy and safety of new chemical entities to be used in the treatment and prevention of glucocorticoid-induced osteoporosis (GIOP).

METHODS

Consensus discussion of the committee.

RESULTS

With the exception of steroid use posttransplantation, there is no need to differentiate between underlying diseases. Prevention and treatment for GIOP are dependent on exposure to glucocorticoids rather than T-scores as in postmenopausal osteoporosis (PMO). If fracture data are obtained for PMO, it need not be repeated for GIOP, relying instead on bone mineral density (BMD) trials of at least 1 year. GREES recommends several changes in the previous guidance for GIOP. The committee saw no need to repeat preclinical studies if those have been previously done to assure bone quality in PMO. Similarly, phase I and phase II trials, if careful dose selection has been done for PMO, should not be repeated. The "prevention" and "treatment" claims should remain. Since the most recent evidence suggests significant increase in fracture risk for daily doses of prednisone of 5 mg/day or equivalent, clinical trials should concentrate on patients receiving at least this daily dosage. The emergence of bisphosphonates as the reference treatment, together with the rapid bone loss and high fracture incidence in glucocorticoid users, necessitates recommending a noninferiority trial design with lumbar spine BMD as the primary endpoint after 1 year.

CONCLUSIONS

Registration of new chemical entities to be used in the management of GIOP should be granted, based on a 1-year noninferiority trial, using BMD as primary outcome and alendronate or risedronate as comparator. Demonstration of antifracture efficacy should have been previously demonstrated in PMO.

The role of stress-induced cortisol in the relationship between depression and decreased bone mineral density

BACKGROUND

This study was designed to test the hypothesis that cortisol mediates the relationship between bone density and depression in postmenopausal women.

METHODS

Nineteen women aged 52-79 who had been assessed for bone mineral density by dual-energy x-ray absorptiometer (DEXA) were evaluated for depression and anxiety. Diurnal and stress-induced measures of salivary cortisol were obtained during the following week and at a laboratory session involving a speech task.

RESULTS

Nine volunteers reported depression while 10 were never depressed. Ever depressed women had significantly lower total lumbar and right femur DEXA Z scores than never depressed (t(17) = 2.5, p = .019 and t(17) = 2.06, p = .05, respectively). Ever depressed women demonstrated a significant increase in salivary cortisol (area under the curve (AUC) = 27.83, SD = 37.64) compared to never depressed women (AUC = -13.34, SD = 19.55) (t(17) = -3.041, p = .007) during a psychological challenge. There were significant inverse relationships between salivary cortisol AUC values and bone density Z scores at every measured bone site. Mediation analyses suggest that 51 - 67% of the association between depression and bone density could be attributed to stress-induced changes in cortisol.

CONCLUSIONS

Cortisol hypersecretion in response to stress may, in part, explain the impact of depression on bone density in post-menopausal women.

Preliminary results of balloon kyphoplasty for vertebral compression fractures in organ transplant recipients

Object

Organ transplant recipients are at risk for vertebral compression fractures (VCFs). The goal of this study was to determine whether kyphoplasty is an effective treatment for VCFs that develop in this patient population.

Methods

Six consecutive patients who had undergone an organ transplant (five liver and one kidney transplant) had a total of 13 symptomatic VCFs that were treated with balloon kyphoplasty. Postprocedure follow-up duration ranged from 6 to 12 months. The mean visual analog scale pain score was 9.3 before treatment and declined to 1.8 after treatment. This improvement was highly significant (p < 0.001). Intake of narcotic drugs decreased or was eliminated in all patients, and there were no complications related to the procedure. There was one instance of clinically insignificant extraosseous cement extravasation. Sagittal alignment was improved by 5° in one patient and was unchanged in the remaining five. During the follow-up period, a new fracture developed adjacent to a treated level in one patient. This was successfully treated with an additional kyphoplasty procedure.

Conclusions

Kyphoplasty can be performed safely in organ transplant recipients with VCF, in whom results are just as favorable as those seen in patients with no history of organ transplantation.

Relationship between bone mineral density and urine level of NTx in rheumatoid arthritis

We analyzed the relationship between the level of type-I collagen N-telopeptide (NTx) in urine (U-NTx) and bone mineral density (BMD) in patients with rheumatoid arthritis (RA). The subjects were 62 female patients with RA who had experienced the menopause 5 years or more before the study commenced, and who had not been treated for osteoporosis. The mean age of the subjects was 61.6 years and the mean disease duration was 13.3 years. They were classified for global functional status (classes I to IV), and then grouped based on the presence or absence of corticosteroid administration. Bone mineral density (BMD) and U-NTx levels were measured. In the presence of corticosteroid administration (CS group; n = 40), the mean level of U-NTx/creatinine (Cr) was 88.8 nM and the percent young adult mean (%YAM) for BMD was 71.2%. In the no corticosteroid (nCS group; n = 22), the values were 72.1 nM and 78.2%, respectively. The U-NTx/Cr value and %YAM were not significantly different between the CS group and the nCS group. A negative correlation was observed between the U-NTx/Cr value and %YAM in both groups (P = 0.005 and P = 0.0265). No significant difference was observed for the U-NTx/Cr value or %YAM between the CS and nCS groups, in any class. In the CS group, a positive correlation was observed between the U-NTx/Cr value and the total dose of corticosteroid (P = 0.001), and a negative correlation was observed between the %YAM and the total dose of corticosteroid (P = 0.003). These results suggested that preventive medical treatment for osteoporosis is required for RA patients in class III, irrespective of whether they have had corticosteroid administration.

Intermittent intravenous ibandronate injections reduce vertebral fracture risk in corticosteroid-induced osteoporosis: results from a long-term comparative study

Despite its well-known benefits, chronic corticosteroid therapy causes osteoporotic fractures in approximately 30-50% of patients treated. To prevent the occurrence of these fractures, treatment with oral bisphosphonates is recommended. However, current oral bisphosphonates, which are given either daily or weekly, are associated with stringent, inconvenient dosing guidelines. Less frequent dosing may provide greater acceptability. The objective of this study was to investigate the efficacy and safety of ibandronate, a highly potent nitrogen-containing bisphosphonate, when given by intravenous (i.v.) injection every 3 months in men and women with established corticosteroid-induced osteoporosis (CIO; lumbar spine [L2-L4] bone mineral density [BMD] T-score < or =-2.5). A total of 115 participants were assigned to receive daily calcium supplements (500 mg) plus either ibandronate (2 mg) injections every 3 months or daily oral alfacalcidol (1 microg), for 3 years. Intermittent i.v. ibandronate injections produced significantly greater increases in mean BMD at the lumbar spine (13.3% versus 2.6%, respectively; p<0.001), and femoral neck (5.2% versus 1.9%, respectively; p<0.001) versus daily oral alfacalcidol, after 3 years, relative to baseline. This study was not statistically powered to show a difference between the groups with respect to fracture incidence. Nevertheless, after 36 months, the frequency of patients with new vertebral fractures was significantly lower in the patients receiving ibandronate relative to those taking alfacalcidol (8.6% versus 22.8%, respectively; p=0.043). This is the first time that significant vertebral fracture reduction has been demonstrated with an i.v. bisphosphonate in CIO. Patients treated with i.v. ibandronate injections also experienced less back pain (p<0.001) and less height loss (p=0.001) than those receiving oral alfacalcidol. Both regimens were well tolerated. In conclusion, intermittent i.v. ibandronate injections are efficacious, well-tolerated, and convenient, and promise to offer physicians an important therapeutic advance in the management of osteoporosis.

Osteoporosis in children who have disabilities

Children who have disabilities are at increased risk for osteoporosis during childhood. This not only puts them at risk for fractures during childhood but also during adulthood. Peak bone mass, which helps predict osteoporosis in adulthood, is never attained in children who have a disability. Care providers of this group of children must be aggressive in the prevention and treatment of osteoporosis. A thorough laboratory evaluation and DXA studies may be undertaken on all disabled children who are at risk for osteoporosis. Although medications have shown promise in the treatment of decreased bone mass, their efficacy in children who have disabilities must be evaluated in larger, controlled studies. Nonpharmocologic treatments also necessitate further exploration.

Effects of high doses of corticosteroids on bone metabolism

The effects of a chronic treatment with corticosteroids on bone are well known, but few data are available regarding the acute effect of these drugs on bone turnover. This study was aimed at evaluating the effects of high doses of corticosteroids administered for a short period on bone metabolism. We assessed 23 subjects (15 women and 8 men) suffering from multiple sclerosis and treated with methylprednisolone (1 g i.v. for 10 days) followed by oral prednisone for 9 days; patients affected by diseases involving bone or treated during the previous 6 months with drugs influencing bone metabolism were excluded. We observed a significant decrease of ALP and bone glia protein (BGP), in these subjects, and a significant sudden increase of urinary calcium/creatinine and urinary cross-laps after 3 days of treatment. All of these parameters, except urinary calcium/creatinine, returned to basal levels after 30 days from the beginning of treatment (11 days after the interruption of corticosteroids administration). Serum phosphorus showed a significant decrease after 3 days of treatment, but returned to basal levels after 10 days. These data suggest that high doses of corticosteroids administered for a short period are able to induce an increase of bone resorption and a decrease of bone formation; moreover, bone turnover returns to basal levels when the treatment is stopped.

The effects of dexamethasone on bone fusion in an experimental model of posterolateral lumbar spinal arthrodesis

OBJECT

The use of corticosteroid agents during the healing phase after spinal arthrodesis remains controversial. Although anecdotal opinion suggests that corticosteroids may inhibit bone fusion, such an effect has not been substantiated in clinical trials or laboratory investigations. This study was undertaken to delineate the effect of exogenous corticosteroid administration on bone graft incorporation in an experimental model of posterolateral lumbar fusion.

METHODS

An established, well-validated model of lumbar intertransverse process spinal fusion in the rabbit was used. Twenty-four adult New Zealand white rabbits underwent L5-6 bilateral posterolateral spinal fusion in which autogenous iliac crest bone graft was used. After surgery, the animals were randomized into two treatment groups: a control group (12 rabbits) that received intramuscular injections of normal saline twice daily and a dexamethasone group (12 rabbits) that received intramuscular dexamethasone (0.05 mg/kg) twice daily. After 42 days, the animals were killed and the integrity of the spinal fusions was assessed by radiography, manual palpation, and biomechanical testing. In seven (58%) of the 12 control rabbits, solid posterolateral fusion was achieved. In no dexamethasone-treated rabbits was successful fusion achieved (p = 0.003). Tensile strength and stiffness of excised spinal segments were significantly lower in dexamethasone-treated animals than in control animals (tensile strength 91.4+/-30.6 N and 145.3+/-48.2, respectively, p = 0.004; stiffness 31.4+/-11.6 and 45.0+/-15.2 N/mm, respectively, p = 0.02).

CONCLUSIONS

The corticosteroid agent dexamethasone inhibited bone graft incorporation in a rabbit model of single-level posterolateral lumbar spinal fusion, inducing a significantly higher rate of nonunion, compared with that in saline-treated control animals.

Osteoporosis for the allergist

OBJECTIVE

This review is intended to be an authoritative summary of the pathogenesis of osteoporosis, a problem that may be encountered in allergy practice. It also provides an outline for identification of subjects at high risk and directions for their appropriate evaluation, management, and prevention of the disease.

DATA SOURCES

References were obtained through a MEDLINE literature search as well as from previous reviews. Relevant articles were critically reviewed and their conclusions were included.

RESULTS

Osteoporosis is a relatively common disease that is associated with significant morbidity and mortality. The management and prevention of osteoporosis have been improved by an increased awareness of the magnitude of the problem, a better understanding of the pathogenesis, development of a better technique for assessment of bone mineral density, and the availability of specific medications. With the increase in human life-span and the increasing use of glucocorticosteroids for a wide variety of diseases, the incidence of osteoporosis has been on the rise.

CONCLUSION

Glucocorticosteroids are the most common medications that cause or contribute to the pathogenesis of osteoporosis and have been widely used in allergy practice. It is important for physicians to appreciate the current basic understanding of osteoporosis and to be able to identify patients at high risk for this serious disorder, and to initiate appropriate intervention at a sufficiently early time to be effective. Medications for treatment and prevention of osteoporosis include: calcium, vitamin D, estrogen, bisphosphonates, calcitonin, and others are reviewed in this article.

Glucocorticoid-induced osteoporosis: prevention and treatment

Glucocorticoid excess carries the risk of inducing secondary osteoporosis. In endogenous Cushing's syndrome, osteoporosis may be the presenting symptom of the underlying disease. Bone loss may reverse after the condition is cured, but often active treatment of established osteoporosis is necessary. In long-term glucocorticoid treatment at therapeutic doses, bone loss is likely and should be prevented; if prevention is ineffective, treatment is necessary. Hypercortisolism impairs calcium homeostasis and bone metabolism in a complex, multifactorial way: Glucocorticoids diminish calcium absorption and increase renal calcium excretion; this negative calcium balance leads to secondary hyperparathyroidism and osteoclast activation. Osteoblast activity is directly impaired by glucocorticoids, which lower activity of the gonadal hormone axis so that hypogonadism also contributes to bone loss. Glucocorticoids lead to muscle atrophy and decreased muscle strength with negative consequences for bone formation. For prevention and treatment, two different strategies have been used. The pathophysiological approach substitutes calcium and vitamin D in the first step; if bone loss nevertheless continues, bone formation is stimulated by fluorides. The alternative pharmaco-dynamic approach uses antiresorptives-calcitonin or, for preference, bisphosphonates. Clinically it is mandatory to monitor all patients in whom glucocorticoids are used (e.g., organ transplant recipients) before and after the initiation of treatment to stabilize bone metabolism as early as possible.

The risks of systemic corticosteroid use

Because of their potent antiinflammatory and immunosuppressive properties, systemic corticosteroids are used to modify a vast array of diseases. This class of drugs, however, has the potential to produce multiple adverse effects presenting the dermatologist with difficult decisions in the management of patients with potentially steroid responsive disorders. This article reviews the side effects of systemic corticosteroids, comments on strategies to minimize these side effects, as well as, outlining suggested mechanisms by which physicians may minimize the risks of medical legal consequences owing to adverse reactions to these drugs.