Glucocorticoid-induced osteoporosis: mechanisms for bone loss; evaluation of strategies for prevention

Osteoporosis is a common complication of chronic glucocorticoid therapy, especially in older patients who already are at risk of having a reduced bone mass. Glucocorticoids cause bone loss by altering the bone remodeling sequence: bone resorption by osteoclasts is increased, and bone formation by osteoblasts is decreased. Serum levels of osteocalcin, a protein made by osteoblasts, are decreased with glucocorticoid therapy, further evidence of decreased osteoblast function. Glucocorticoids decrease calcium absorption by the gastrointestinal tract and increase renal calcium excretion. Several recent studies suggest that low-dose glucocorticoid therapy is not associated with bone loss. Calcium supplementation with vitamin D is recommended. Several short-term studies have shown prevention of glucocorticoid-induced bone loss with bisphosphonates, calcitonin, and progesterone. Long-term clinical trials should be undertaken to determine strategies to prevent this type of osteoporosis.     

Glucocorticoid-induced osteoporosis: an update.

Glucocorticoid-induced osteoporosis occurs in two phases: a rapid, early phase in which bone mineral density is reduced, possibly as a result of excessive bone resorption, and a slower, progressive phase in which bone mineral density declines because of impaired bone formation. Although the indirect effects of glucocorticoids on bone are evident, their direct effects on osteoblasts, osteoclasts and osteocytes are primarily operative in the pathogenesis of glucocorticoid-induced osteoporosis. The management of patients exposed to glucocorticoids includes general health measures, sufficient calcium and vitamin D, and reducing the therapeutic regimen to the minimal effective dose. The gold standard in the pharmacological treatment of glucocorticoid-induced osteoporosis in postmenopausal women involves the use of bisphosphonates, which should be started soon after beginning chronic glucocorticoid therapy. Anabolic and alternative therapeutic strategies are currently under investigation in glucocorticoid-induced osteoporosis.     

Recognizing and treating glucocorticoid-induced osteoporosis in patients with pulmonary diseases

Glucocorticoids are frequently used to treat patients with pulmonary diseases, but continuous long-term use of glucocorticoids may lead to significant bone loss and an increased risk of fragility fractures. Patients with certain lung diseases, regardless of pharmacotherapy-particularly COPD and cystic fibrosis-and patients waiting for lung transplantation are also at increased risk of osteoporosis. Fragility fractures, especially of the hip, will have substantial effects on the health and well-being of older patients. Vertebral collapse and kyphosis secondary to glucocorticoid-induced osteoporosis (GIO) may affect lung function. Identification of patients with osteopenia, osteoporosis, or fragility fractures related to osteoporosis is strongly recommended and should lead to appropriate treatment. Prevention of GIO in patients receiving continuous oral glucocorticoids is also recommended. In patients receiving either high-dose inhaled glucocorticoids or low- to medium-dose inhaled glucocorticoids with frequent courses of oral glucocorticoids, bone mineral density measurements should be performed to screen for osteopenia and osteoporosis. A bisphosphonate (risedronate or alendronate), calcium and vitamin D supplementation, and lifestyle modifications are recommended for the prevention and treatment of GIO.     

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.     

Glucocorticoid-induced osteoporosis

Glucocorticoid-induced osteoporosis is the most frequent cause of secondary osteoporosis. Glucocorticoids cause a rapid bone loss in the first few months of use, but the most important effect of the drug is suppression of bone formation. The administration of oral glucocorticoid is associated with an increased risk of fractures at the spine and hip. The risk is related to the dose, but even small doses can increase the risk. Patients on glucocorticoid therapy lose more trabecular than cortical bone and the fractures are more frequent at the spine than at the hip. Calcium, vitamin D and activated forms of vitamin D can prevent bone loss and antiresorptive agents are effective for prevention and treatment of bone loss and to decrease fracture risk. Despite the known effects of glucocorticoids on bone, only a few patients are advised to take preventive measures and treat glucocorticoid-induced osteoporosis.     

Risk factors for osteoporosis in female patients with systemic lupus erythematosus

In the last years it has been recognized that patients with systemic lupus erythematosus (SLE) are at high risk of osteoporosis (OP) and fractures, both occurring through disease-specific (chronic arthritis, reduced physical activity, induction of cytokines promoting bone resorption, renal impairment, endocrine factors) and nondisease-specific mechanisms (sunshine avoidance with consequent vitamin D deficiency, glucocorticoids, immunosuppressants and chronic anticoagulants). Regarding anticoagulants, subcutaneous heparin is crucial against the risk of recurrent thromboembolism or pregnancy loss, specifically in patients with SLE and anti-phospholipid syndrome (APS). Thus heparin-induced OP represents one of the hazards of this treatment, first because heparin must be used long-term and secondly because pregnancy and lactation themselves may predispose to OP and fractures. Current data suggest the use of prophylaxis with calcium and vitamin D in all patients treated with heparin during pregnancy. Nevertheless glucocorticoid-induced OP (GIOP) is considered the most serious risk factor for OP and fractures in SLE patients. All guidelines recommend general measures and supplementation with calcium and vitamin D in all patients. However when considering premenopausal patients, there is no generally recommended treatment. Bisphosphonates, which are considered the first choice therapy for the prevention and treatment of GIOP, should be used 'cautiously' in these patients. Therefore the potential risks and lack of efficacy data on fracture risk reduction in premenopausal patients must be weighed against their proven efficacy in postmenopausal patients.     

Glucocorticoid-induced osteoporosis: pathogenesis and management

PURPOSE: To review the clinical picture, pathogenesis, and management of glucocorticoid-induced osteoporosis. DATA IDENTIFICATION: Studies published since 1970 were identified from a MEDLINE search, articles accumulated by the authors, and through bibliographies of identified articles. STUDY SELECTION: Information for review was taken from 160 of the more than 200 articles examined. DATA EXTRACTION: Pertinent studies were selected; the relative strengths and weaknesses of these studies are discussed. RESULTS OF DATA SYNTHESIS: Studies in tissue and organ cultures suggest that glucocorticoids have a direct effect on bone, causing inhibition of bone formation and enhancing bone resorption. Glucocorticoids decrease calcium absorption from the intestine and increase renal excretion. Osteoporosis occurs in at least 50% of persons who require long-term glucocorticoid therapy. Long-term trials of therapy for the prevention of glucocorticoid-induced osteoporosis have not been done, but reasonable recommendations include the use of a glucocorticoid with a short half-life in the lowest dose possible, maintenance of physical activity, adequate calcium and vitamin D intake, sodium restriction and use of thiazide diuretics, and gonadal hormone replacement. In refractory cases, the use of calcitonin, bisphosphonates, sodium fluoride, or anabolic steroids should be considered. CONCLUSIONS: Osteoporosis is common in patients requiring long-term treatment with glucocorticoids. Careful attention to preventive management may minimize the severity of this serious complication.     

Therapy Insight: osteoporosis and osteonecrosis in systemic lupus erythematosus

Survival of patients with systemic lupus erythematosus (SLE) has improved over the past decade, thanks to improved treatment of the disease, which now results in fewer fatal complications. This improvement has allowed physicians to focus their attention on the prevention of organ damage caused by this chronic, inflammatory disease, and by the medications used to control the disease. Osteoporosis is common in SLE patients; risk factors for osteoporosis include prolonged use of glucocorticoids, cyclophosphamide and possibly gonadotropin-releasing-hormone agonists. In premenopausal women with SLE, inflammation or SLE-related medications can increase bone turnover, which eventually weakens bone architecture, then reduces bone strength and increases the risk of fracture. Prevention and treatment of osteoporosis in SLE patients should entail a multifaceted approach. Levels of calcium, vitamin D and homocysteine should be evaluated, and age-appropriate supplementation instituted. The bone loss that results from systemic inflammation should be treated by reduction of the inflammation with glucocorticoids, potent anti-inflammatory agents or antiresorptive agents. The efficacy of this therapy can be monitored using bone mineral density scans. This Review briefly discusses the pathophysiology of the localized and generalized osteoporosis and osteonecrosis in SLE patients and recommends therapies to both prevent and treat these unfortunate complications of this disease.     

Calcium and vitamin D in osteoporosis

Calcium and vitamin D are useful adjunctive therapies in the prevention and treatment of osteoporosis. Peak BMD is optimally achieved with sustained optimal calcium and vitamin D intakes. Calcium and vitamin D intakes continue to be important after the third decade and into senescence. Although calcium and vitamin D are not therapies to be used alone to prevent early postmenopausal bone loss, they assume more prominent roles in late menopause and in the elderly to preserve bone health with advancing age. Calcium and vitamin D supplementation is an important adjunctive therapy to use together with antiresorptive therapies.     

Clinical Question: What is the best approach to managing glucocorticoid‐induced osteoporosis?

Glucocorticoid-induced osteoporosis is common, and the resulting fractures cause significant morbidity and mortality. Rapid bone loss and increased fracture risk occur soon after the initiation of glucocorticoid therapy and are dose dependent. The increase in fracture risk is partly independent of bone mineral density, probably as a result of changes in bone material properties and increased risk of falling. Fracture risk can be assessed using the FRAX algorithm, although risk may be underestimated in patients taking higher doses of glucocorticoids. Because of the rapidity of bone loss and increase in fracture risk after the start of glucocorticoid therapy, primary prevention should be advised in high-risk individuals, for example older women and men, individuals with a previous fracture history and those with low bone mineral density. Bisphosphonates are the front-line choice for the prevention of fracture in the majority of glucocorticoid-treated patients, with teriparatide as a second-line option. Calcium and vitamin D supplements should be co-prescribed unless there is evidence of an adequate dietary calcium intake and vitamin D status.     

Prevention and treatment strategies for glucocorticoid-induced osteoporotic fractures

Glucocorticoids are the most common cause of drug-related osteoporosis. We reviewed current evidence on risk factors for glucocorticoid-induced osteoporosis (GIOP) and prevention and treatment of GIOP-related fractures. Guidelines for GIOP management published since 2000 were also reviewed. Significant bone loss and increased fracture risk is seen with daily prednisone doses as low as 5 mg. Alternate-day glucocorticoid therapy can lead to similar bone loss. No conclusive evidence exists for a safe minimum dose or duration of glucocorticoid exposure. Physicians should consider risk factors for involutional osteoporosis such as older age, postmenopausal status, and baseline bone density measurements as they assess patients for prevention or treatment of GIOP. Bisphosphonates were reported to reduce GIOP-related vertebral fractures, but inconclusive data exist for hip fractures associated with glucocorticoid use. Hormone replacement therapy and parathyroid hormone analogs are effective in preserving bone density in GIOP. The risk of osteoporosis and fractures should be routinely assessed in patients receiving glucocorticoid therapy. Effective prevention and treatment options are available and can result in meaningful reduction of GIOP-related morbidity and mortality. Current guidelines for GIOP management recommend bisphosphonates, especially alendronate and risedronate, as first-line agents for GIOP, and these guidelines propose the preventive use of bisphosphonates early in the course of glucocorticoid therapy in high-risk patient subgroups.     

Effect of oral 1,25-dihydroxyvitamin D and calcium on glucocorticoid-induced osteopenia in patients with rheumatic diseases

Twenty-three rheumatic disease patients with glucocorticoid-induced osteopenia (defined by measurement of forearm bone mass) completed an 18-month double-blind, randomized study to assess the effect of oral calcium and 1,25-dihydroxyvitamin D (1,25-OH2D) or calcium and placebo on bone and mineral metabolism. Intestinal 47Ca absorption was increased (P less than 0.05) and serum parathyroid hormone levels were suppressed (P less than 0.01) by 1,25-OH2D (mean dose 0.4 micrograms/day); however, no significant gain in forearm bone mass occurred, and bone fractures were frequent in both groups. In the 1,25-OH2D group, histomorphometric analysis of iliac crest biopsy specimens demonstrated a decrease in osteoclasts/mm2 of trabecular bone (P less than 0.05) and parameters of osteoblastic activity (P less than 0.05), indicating that 1,25-OH2D reduced both bone resorption and formation. We conclude that 1,25-OH2D should not be used for treatment of glucocorticoid-induced osteopenia. Since patients receiving calcium and placebo did not exhibit a loss of forearm bone mass, elemental calcium supplementation of 500 mg daily might be useful to maintain skeletal mass in patients receiving long-term glucocorticord therapy.     

Relative value of plain vitamin D and of biologically active vitamin D in the prevention and treatment of osteoporosis

Vitamin D metabolism has an important role in the pathogenesis of osteoporosis. Vitamin D deficiency is very common in elderly people in central Europe. This leads to secondary hyperparathyroidism and to increased bone resorption, resulting in osteoporosis. Combined with the elevated risk of falling that results from vitamin D deficiency, this increases the frequency of bone fractures. Severe vitamin D deficiency also causes impaired bone mineralization (osteomalacia). Controlled intervention trials with native vitamin D (and calcium) yielded no consistent results in terms of the prevention of extravertebral fractures. It appears likely that treatment with plain vitamin D is effective only in populations with vitamin D deficiency. Treatment with active vitamin D (1-alpha-hydroxylated metabolites such as alfacalcidol) has to be considered a pharmacological intervention that exerts pleiotropic effects on the gut (calcium absorption), bone (stimulation of formation), muscle (decreasing of the risk of falling), and immune system. Target groups are patients with disturbed vitamin D metabolism (renal insufficiency, glucocorticoid therapy, inflammatory disease such as rheumatoid arthritis). Alfacalcidol can prevent glucocorticoid-induced bone loss (high-grade evidence). In comparative studies alfacalcidol was superior to plain vitamin D.     

Effectiveness and safety of routine calcium supplementation in postmenopausal women. A narrative review

BackgroundTo determine whether routine administration of calcium supplementation is useful in postmenopausal women, while it is associated with an increased risk of cardiovascular complications.MethodsA literature search was performed using Medline/PubMed, Scopus and Google Scholar by using relevant keywords.ResultsCalcium supplement exerts a small protective effect against bone loss which disappears after cessation. Antifracture effect of supplemental calcium is limited to older frail women or community-dwelling residents who are vitamin D deficient and have inadequate dietary calcium intake. The results of studies on the association between calcium supplementation and cardiovascular complications are contradictory and do not lead to a decisive conclusionConclusionCurrent data do not support routine calcium supplementation to all postmenopausal women for prevention of bone loss or bone fracture.     

Glucocorticoid-induced osteoporosis: pathogenesis,prevention and treatment,with special regard to the rheumatic diseases

Abstract. Objectives. To review factors associated with development of osteoporosis in patients with rheumatic diseases, as well as the preventive and therapeutic measures. Design. A MEDLINE literature search. Results. 1 Pathogenesis. Rheumatoid arthritis in itself causes reduction of bone mass; this process can be aggravated by glucocorticoid treatment. With glucocorticoid treatment, bone mineral density decrease is most pronounced during the first months of treatment. There is no agreement on the effects of daily dose, cumulative dose, and duration of glucocorticoid treatment on the rate of bone loss. However, with treatment by low doses (< 10 mg of prednisone equivalent per day), bone loss appears to be minimal or even undetectable compared to controls. Alternate day treatment, or treatment with steroid ‘pulses’ have not been shown to protect from bone loss. 2 Prevention and treatment. Prophylactic and therapeutic measures for glucocorticoid-induced osteoporosis include calcium supplementation, vitamin D in physiological doses and oestrogen in perimenopausal female patients. Efficacy has not always been shown in this particular indication but is extrapolated from other forms of osteoporosis. Limited data exist on treatment with anabolic steroids, calcitonin (with an additional analgesic effect) and biphosphonates and reduction of fracture rates has not yet been investigated. At present, there is insufficient evidence to show that altered steroid molecules can dissociate adverse effects on bone from clinically desirable effects. Conclusion. In view of the paucity of study data, prophylaxis and therapy of glucocorticoid-induced osteoporosis should receive more attention in future clinical studies.     

Calcium,vitamin D and etidronate for the prevention and treatment of corticosteroid-induced osteoporosis in patients with rheumatic diseases

INTRODUCTION: Long-term glucocorticoid therapy, a major risk factor for the development of osteoporosis, is often necessary in chronically ill patients. At present there are no generally accepted guidelines for the prevention or treatment of steroid-induced osteoporosis. METHODS: In an open prospective study we investigated 99 patients with chronic rheumatic diseases receiving > or = 5 mg/day of prednisolone or the equivalent for at least one year. The objective was to identify osteoporosis risk factors in addition to glucocorticoid therapy and to evaluate the efficacy of prevention with calcium/vitamin D (group 1--patients with osteopenia) and treatment with cyclical etidronate (group 2--patients with osteoporosis). Biochemical markers of bone turnover, clinical parameters and bone mineral density (BMD) were measured. RESULTS: Increasing age and postmenopausal status were associated with more advanced manifestations of steroid-induced osteoporosis (p < 0.05). One year after the start of therapy parameters of bone metabolism increased significantly in group 1, while BMD did not change. In group 2, lumbar spine BMD increased significantly (p < 0.05) whereas femoral neck BMD and bone metabolism parameters remained constant. The intensity of back pain decreased in both groups (p < 0.05). There were fewer new fractures in group 2 than in group 1. CONCLUSION: Treatment with etidronate is effective in patients with glucocorticoid-induced osteoporosis.