Superiority of alfacalcidol over plain vitamin D in the treatment of glucocorticoid-induced osteoporosis

Efficacy and safety of 18 anti-osteoporotic drugs in the treatment of patients with osteoporosis caused by glucocorticoid: A network meta-analysis of randomized controlled trials

Background

Glucocorticoids are widely used in a variety of diseases, especially autoimmune diseases and inflammatory diseases, so the incidence of glucocorticoid-induced osteoporosis is high all over the world.

Objectives

The purpose of this paper is to use the method of network meta-analysis (NMA) to compare the efficacy of anti-osteoporosis drugs directly and indirectly, and to explore the advantages of various anti-osteoporosis drugs based on the current evidence.

Methods

We searched PubMed, Embase and Cochrane Library for randomized controlled trials (RCTs), of glucocorticoid-induced osteoporosis (GIOP) and compared the efficacy and safety of these drugs by NMA. The risk ratio (RR) and its 95% confidence interval (CI) are used as the influence index of discontinuous data, and the standardized mean difference (SMD) and its 95% CI are used as the influence index of continuous data. The statistical heterogeneity was evaluated by the calculated estimated variance (τ²), and the efficacy and safety of drugs were ranked by the surface under the cumulative ranking curve (SUCRA). The main outcome of this study was the incidence of vertebral fracture after taking several different types of drugs, and the secondary results were the incidence of non-vertebral fracture and adverse events, mean percentage change of lumbar spine (LS) and total hip (TH)bone mineral density (BMD) from baseline to at least 12 months.

Results

Among the different types of anti-GIOP, teriparatide (SUCRA 95.9%) has the lowest incidence of vertebral fracture; ibandronate (SUCRA 75.2%) has the lowest incidence of non-vertebral fracture; raloxifene (SUCRA 98.5%) has the best effect in increasing LS BMD; denosumab (SUCRA 99.7%) is the best in increasing TH BMD; calcitonin (SUCRA 92.4%) has the lowest incidence of serious adverse events.

Conclusions

Teriparatide and ibandronate are effective drugs to reduce the risk of vertebral and non-vertebral fractures in patients with GIOP. In addition, long-term use of raloxifene and denosumab can increase the BMD of LS and TH.

Plain vitamin D or active vitamin D in the treatment of osteoporosis: where do we stand today?

Osteoporosis is a major cause of morbidity and mortality worldwide and its prevention in order to avert fractures was considered of great importance in maintaining well-being and independence among the elderly. Strategies for osteoporosis prevention are well delineated, but research shows that the treatment options offered today could still be improved. The role of plain vitamin D (cholecalciferol) in bone health and the prevention of osteoporosis are well documented; however, as a treatment for osteoporosis, either with or without calcium, it has been shown to be ineffective. This is due in part to the strong negative feedback mechanisms in place in vitamin D-replete patients. However, other factors linked directly to ageing such as oestrogen depletion, reduced kidney or liver function may also be involved in reducing the body's capability to activate plain vitamin efficiently. This is why active vitamin D analogues such as alfacalcidol, 1-α-(OH)D3, are of clinical interest. Alfacalcidol requires only one hydroxylation reaction to become active 1,25-(OH)2-vitamin D3, and the 25-hydroxylase catalyzing this reaction is found in the liver and also interestingly in osteoblasts suggesting a local effect. Registered for use in postmenopausal osteoporosis, in most countries worldwide, alfacalcidol has also shown efficacy in glucocorticoid-induced and male osteoporosis. The present review provides compelling evidence for the efficacy of this compound in the treatment of osteoporosis and prevention of fractures both in monotherapy and when combined with other osteoporotic drugs where additive effects are clear. The safety profile of alfacalcidol is shown to be highly acceptable and it is considered less likely to induce hypercalcaemia than another more widely used analogue, calcitriol. Therefore, it remains unclear as to why alfacalcidol is not more widely used in clinical practice.

[Vitamin D metabolism in hypercorticism and acromegaly]

Due to the high prevalence of low vitamin D levels in the overwhelming majority of regions of the world and discovery of extra-skeletal effects of vitamin D, the issue of maintaining adequate levels of vitamin D in the blood remains extremely relevant, especially in people with high risk of severe deficiency. To date, few studies have been performed on the features of vitamin D metabolism in disorders such as hypercorticism and acromegaly. However, vitamin D deficiency in such patients, according to available literature, may be more widespread and more pronounced than in general population. It is now recommended to use standard prophylactic and therapeutic doses of vitamin D for the treatment of these diseases, which may not satisfy the therapeutic goals specific to each disease. This review provides information on normal vitamin D metabolism, as well as literature data on the possible relationship and mutual influence between these endocrinopathies and vitamin D metabolism.

Controversies in Vitamin D: Summary Statement From an International Conference

CONTEXT

Vitamin D is classically recognized as a regulator of calcium and phosphorus metabolism. Recent advances in the measurement of vitamin D metabolites, diagnosis of vitamin D deficiency, and clinical observations have led to an appreciation that along with its role in skeletal metabolism, vitamin D may well have an important role in nonclassical settings. Measurement of the circulating form of vitamin D that best describes total body stores, namely 25-hydroxyvitamin D, can be unreliable despite many sophisticated methodologies that have been proposed and implemented. Likewise, evidence from clinical studies showing a beneficial role of vitamin D in different disease states has been controversial and at times speculative. Moreover, the target concentrations of 25-hydroxyvitamin D to address a number of putative links between vitamin D inadequacy and nonskeletal diseases are further areas of uncertainty.

SETTING

To address these issues, an international conference on "Controversies in Vitamin D" was held in Pisa, Italy, in June 2017. Three main topics were addressed: (i) vitamin D assays and the definition of hypovitaminosis D; (ii) skeletal and extraskeletal effects of vitamin D; (iii) therapeutics of vitamin D.

RESULTS

This report provides a summary of the deliberations of the expert panels of the conference.

CONCLUSIONS

Despite great advances in our appreciation of vitamin D metabolism, measurements, biological actions on classical and nonclassical tissues, and therapeutics, all of which this report summarizes, much more work remains to be done so that our knowledge base can become even more secure.

MANAGEMENT OF ENDOCRINE DISEASE: Therapeutics of Vitamin D

OBJECTIVE

The central role of vitamin D in bone health is well recognized. However, controversies regarding its clinical application remain. We therefore aimed to review the definition of hypovitaminosis D, the skeletal and extra-skeletal effects of vitamin D and the available therapeutic modalities.

DESIGN

Narrative and systematic literature review.

METHODS

An international working group that reviewed the current evidence linking bone and extra-skeletal health and vitamin D therapy to identify knowledge gaps for future research.

RESULTS

Findings from observational studies and randomized controlled trials (RCTs) in vitamin D deficiency are discordant, with findings of RCTs being largely negative. This may be due to reverse causality with the illness itself contributing to low vitamin D levels. The results of many RCTs have also been inconsistent. However, overall evidence from RCTs shows vitamin D reduces fractures (when administered with calcium) in the institutionalized elderly. Although controversial, vitamin D reduces acute respiratory tract infections (if not given as bolus monthly or annual doses) and may reduce falls in those with the lowest serum 25-hydroxyvitamin D (25OHD) levels. However, despite large ongoing RCTs with 21 000–26 000 participants not recruiting based on baseline 25OHD levels, they will contain a large subset of participants with vitamin D deficiency and are adequately powered to meet their primary end-points.

CONCLUSIONS

The effects of long-term vitamin D supplementation on non-skeletal outcomes, such as type 2 diabetes mellitus (T2DM), cancer and cardiovascular disease (CVD) and the optimal dose and serum 25OHD level that balances extra-skeletal benefits (T2DM) vs risks (e.g. CVD), may soon be determined by data from large RCTs.

Fracture risk in oral glucocorticoid users: a Bayesian meta-regression leveraging control arms of osteoporosis clinical trials

Little data exist on the frequency of fracture among oral glucocorticoid users. We examined the effect of oral glucocorticoids on fracture incidence using data from randomized controlled trials. Patients starting glucocorticoids had a higher probability of fracture and decline in bone mineral density compared to chronic glucocorticoid users.

INTRODUCTION

Oral glucocorticoids (GCs) are the leading cause of secondary osteoporosis. However, there have been few studies that quantify the rate of fracture among GC users. We sought to provide a pooled estimate of fracture risk from randomized controlled trials (RCTs) of GC-treated patients.

METHODS

We updated a MEDLINE search published by the American College of Rheumatology through to March 2015 and identified RCTs of osteoporosis therapies that reported fracture and bone mineral density (BMD) among oral GC users. We restricted the analysis to placebo or control arms. RCT arms were stratified by GC exposure at enrolment to GC initiators (≤6 months) and chronic GC users (>6 months). Bayesian meta-regression was used to estimate the annual probability of vertebral fracture (primary), non-vertebral fracture and percentage change in lumbar spine and femoral neck BMD.

RESULTS

The annual incidence of vertebral and non-vertebral fracture was 5.1 % (95 % CrI = 2.8-8.2) and 2.5 % (95 % CrI = 1.2--4.2) among GC initiators, and 3.2 % (95 % CrI = 1.8-5.0) and 3.0 % (95 % CrI = 0.8-5.9) among chronic GC users. Our meta-regression identified a non-significant effect of group-level variables (mean age, mean BMD, mean GC daily dose, patients with previous vertebral fractures, proportion of women and adjuvant used) on vertebral fracture rate.

CONCLUSION

Our study found higher vertebral fracture incidence among GC initiators, yet a relative decline in fracture incidence with longer exposure. Our findings suggest that fracture incidence among oral GC users may be more common than previously estimated. Optimizing GC-induced osteoporosis management during early exposure to GC is essential to prevent fractures.

The clinical use of vitamin D metabolites and their potential developments: a position statement from the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) and the International Osteoporosis Foundation (IOF)

Several compounds are produced along the complex pathways of vitamin D3 metabolism, and synthetic analogs have been generated to improve kinetics and/or vitamin D receptor activation. These metabolites display different chemical properties with respect to the parental or native vitamin D3, i.e., cholecalciferol, which has been, so far, the supplement most employed in the treatment of vitamin D inadequacy. Hydrophilic properties of vitamin D3 derivatives facilitate their intestinal absorption and their manageability in the case of intoxication because of the shorter half-life. Calcidiol is a more hydrophilic compound than parental vitamin D3. Active vitamin D analogs, capable of binding the vitamin D receptor evoking vitamin D-related biological effects, are mandatorily employed in hypoparathyroidism and kidney failure with impaired 1α-hydroxylation. They have been shown to increase BMD, supposedly ameliorating calcium absorption and/or directly affecting bone cells, although their use in these conditions is jeopardized by the development of hypercalciuria and mild hypercalcemia. Further studies are needed to assess their overall safety and effectiveness in the long-term and new intermittent regimens, especially when combined with the most effective antifracture agents.

Vitamin D for the treatment of chronic painful conditions in adults

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (Issue 1, 2010) on 'Vitamin D for the treatment of chronic painful conditions in adults'.Vitamin D is produced in the skin after exposure to sunlight and can be obtained through food. Vitamin D deficiency has been linked with a range of conditions, including chronic pain. Observational and circumstantial evidence suggests that there may be a role for vitamin D deficiency in the aetiology of chronic painful conditions.

OBJECTIVES

To assess the efficacy and safety of vitamin D supplementation in chronic painful conditions when tested against placebo or against active comparators.

SEARCH METHODS

For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE to February 2015. This was supplemented by searching the reference lists of retrieved articles, reviews in the field, and online trial registries.

SELECTION CRITERIA

We included studies if they were randomised double-blind trials of vitamin D supplementation compared with placebo or with active comparators for the treatment of chronic painful conditions in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, assessed methodological quality, and extracted data. We did not undertake pooled analysis due to the heterogeneity of the data. Primary outcomes of interest were pain responder outcomes, and secondary outcomes were treatment group average pain outcomes and adverse events.

MAIN RESULTS

We included six new studies (517 participants) in this review update, bringing the total of included studies to 10 (811 participants). The studies were heterogeneous with regard to study quality, the chronic painful conditions that were investigated, the dose of vitamin D given, co-interventions, and the outcome measures reported. Only two studies reported responder pain outcomes; the other studies reported treatment group average outcomes only. Overall, there was no consistent pattern that vitamin D treatment was associated with greater efficacy than placebo in any chronic painful condition (low quality evidence). Adverse events and withdrawals were comparatively infrequent, with no consistent difference between vitamin D and placebo (good quality evidence).

AUTHORS' CONCLUSIONS

The evidence addressing the use of vitamin D for chronic pain now contains more than twice as many studies and participants than were included in the original version of this review. Based on this evidence, a large beneficial effect of vitamin D across different chronic painful conditions is unlikely. Whether vitamin D can have beneficial effects in specific chronic painful conditions needs further investigation.

Ten common mistakes in the management of lupus nephritis

Management of patients with lupus nephritis can be complex and challenging. We suggest that there are some widely held misconceptions about lupus, and unfortunately, these underpin the treatment of many patients. There is little evidence to support the common assumption that intravenous pulse cyclophosphamide is the best treatment for lupus nephritis. Although there is much focus on which immunosuppressive agent to use, too little attention is paid to the proper dose and duration of corticosteroids and concomitant therapy with antimalarial agents. Many clinicians reflexively perform kidney biopsies when these biopsies may be high risk and not influence therapy. There is little emphasis on or awareness of nonadherence to therapy, which is an underappreciated cause of treatment resistance. Resolution of proteinuria and hematuria can take a long time, and immunotherapy should not be intensified based on urine sediment alone. Furthermore, the intensity of the immunosuppression must be considered in the context of lupus nephritis class and duration of kidney damage. Finally, clinicians are aware of the risks of pregnancy in the face of active lupus, but assume that their patients also are aware of this and forget to discuss this with them. With a combined experience of more than 50 years in managing children and adults with lupus, we offer our impression of recurrent mistakes in the management of lupus in general, with a focus on treatment of lupus nephritis.

Vitamin D status and bone density in steroid-treated children with glomerulopathies: effect of cholecalciferol and calcium supplementation

PURPOSE

The aim of this study was to assess vitamin D status and bone density in steroid-treated children with glomerulopathies and to evaluate the effect of prophylactic vitamin D and calcium supplementation.

MATERIAL AND METHODS

Retrospective analysis was performed on 55 children aged 4-18 yrs with glomerulopathies. The following data were analyzed: antropometrical parameters, bone densitometries, parathormone, 25-hydroxyvitamin D (25-OHD), urinary calcium excretion and medications received for prevention of low bone mass.

RESULTS

A significant number of children (38%) had decreased spinal bone mineral density (BMD z-score < -2.0) and the majority of them (89%) had hypovitaminosis D (25-OHD < 30 ng/ml), 75% were vitamin D insufficient (25-OHD < 20 ng/ml) and 16% were vitamin D deficient (25-OHD < 10 ng/ml). The mean serum 25-OHD concentration was comparable to that of controls (19.32 ± 12.87 vs. 15.05 ± 8.52 ng/ml). Nearly all patients (82%) were receiving preparations of calcium and/or vitamin D to improve bone health. Patients on cholecalciferol had higher mean concentration of 25-OHD compared to those who were not receiving it (p=0.027) and to the controls (p=0.047). In 23 children on vitamin D and calcium supplementation for an average 6-month time, we observed an increase in the mean BMD values (p=0.004), however, mean BMD z-score and 25-OHD concentrations did not significantly change over time.

CONCLUSIONS

Vitamin D and bone density deficits are remarkably common in steroid-treated children with glomerulopathies, despite vitamin D and calcium repletion. In order to enhance the effectiveness of vitamin D supplementation for improvement of bone density, we suggest regular assessment of serum concentration of 25-OHD that can guide subsequent dose adjustment of vitamin D.

Alfacalcidol in men with osteoporosis: a prospective, observational, 2-year trial on 214 patients

Due to pleiotropic-synergistic actions on bone, muscle, gut, brain and different other non-skeletal tissues, alfacalcidol is an interesting drug for treating osteoporosis. In studies on glucocorticoid-induced osteoporosis, men have always been treated with calcitriol or this active D-hormone prodrug, but there is no study of male patients only in the literature. The AIM-Trial (Alfacalcidol In Men) is an extension of the control group (n = 158) of our former risedronate study in male osteoporosis (Ringe et al. in Rheumatol Int 29:311-315, 2009). In that study, we treated daily those controls with prevalent vertebral fractures with 1 μg alfacalcidol + 500 mg calcium (group A) and those without prevalent vertebral fractures with 1,000 IU plain vitamin D (Vit. D) + 1,000 mg calcium (group B). Subsequently, we added an additional 56 pairs of patients to these two groups: 28 with and 28 without prevalent vertebral fractures, reaching a total of 214 cases. That means with this design, we are comparing two groups with a different risk at onset. Due to the prevalent vertebral fractures and lower average bone mineral density (BMD) values, there was a higher risk of incident fractures in group A. After 2 years, we found significantly higher increases in lumbar spine BMD (+3.2 vs. +0.8 %) and total hip BMD (+1.9 vs. -0.9 %) in group A and B, respectively. Eighteen incident falls were recorded in the alfacalcidol group and 38 in the group treated with Vit. D (p = 0.041). There were significantly lower rates of patients with new vertebral and non-vertebral fractures in group A than in group B. Back pain was significantly reduced only with alfacalcidol. Concerning the incidence of new non-vertebral fractures, we found that there was a relation to renal function in the two groups. The advantage for alfacalcidol was mainly due to a higher non-vertebral fracture-reducing potency in patients with a creatinine clearance (CrCl) below 60 ml/min (p = 0.0019). There were no serious adverse events (SAE), and the numbers of mild-to-moderate adverse events (AE) were not different between groups. Despite the higher initial fracture risk in the alfacalcidol group, 2-year treatment with this active D-hormone prodrug showed a higher therapeutic efficacy in terms of BMD, falls and fractures. One important advantage of alfacalcidol may be that it is effective even in patients with mild-to-moderate renal insufficiency.

Vitamin D for the treatment of chronic painful conditions in adults

BACKGROUND

Vitamin D is produced in the skin after sun-light exposure and can also be obtained through food. Vitamin D deficiency has recently been linked with a range of diseases including chronic pain. Observational and circumstantial evidence suggests that there may be a role for vitamin D deficiency in the aetiology of chronic pain conditions.

OBJECTIVES

To assess the efficacy and adverse events of vitamin D supplementation in chronic painful conditions.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to September 2009. This was supplemented by searching the reference lists of retrieved articles, textbooks and reviews.

SELECTION CRITERIA

Studies were included if they were randomised double blind trials of vitamin D supplementation compared with placebo or with active comparators for the treatment of chronic pain conditions in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, assessed methodological quality, and extracted data. Pooled analysis was not undertaken due to paucity and heterogeneity of data.

MAIN RESULTS

Four studies, with a total of 294 participants, were included. The studies were heterogeneous with regard to study quality, the chronic painful conditions that were investigated, and the outcome measures reported. Only one study reported a beneficial effect, the others found no benefit of vitamin D over placebo in treating chronic pain.

AUTHORS' CONCLUSIONS

The evidence base for the use of vitamin D for chronic pain in adults is poor at present. This is due to low quality and insufficient randomised controlled trials in this area of research.

Potential of alfacalcidol for reducing increased risk of falls and fractures

There are no general accepted strategies for combined drug treatments in osteoporosis, while in other important chronic diseases combinations of different medications are used as a rule to improve therapeutic results and reduce the risk of adverse events. It is suggested that the success of combined treatments is related to the different modes of action of the respective single therapies. On the other hand it was shown that a strong antiresorptive bisphosphonate is able to blunt at least in part the effects of anabolic parathyroid hormone peptides Calcitriol, the active vitamin D-hormone and its prodrug alfacalcidol lead to pleiotropic effects on bone remodelling (antiresorptive, anabolic and enhancing mineralization) and in addition to effects on other important target tissues (e.g. gut, parathyroid glands, muscle). With active D-analogs significant improvements in the therapeutic outcome of osteoporosis can be achieved by the resulting improvements of bone quality, calcium absorption and risk reduction of falling. The same beneficial effects cannot be achieved with plain vitamin D due to feedback controlled, limited renal activation or insufficient conversion in the elderly with impairment of renal function. Accordingly alfacalcidol, approved as a treatment for different forms of osteoporosis, is besides adoption as a mono-therapy an interesting candidate for combined therapies. There are interesting preclinical trials and clinical pilote studies in the literature proving that a parallel therapy with selectively anti-osteoclastic bisphophonates and pleiotropically acting D-analogs is able to optimize therapeutic results in osteoporosis. In the AAC-Trial (Alfacalcidol-Alendronate-Combined) we studied 90 patients with established osteoporosis (57 women, 33 men) over two years after alternate allocation to three treatment arms (alfacalcidol plus calcium, alendronate plus plain vitamin D and Ca, and alendronate plus alfacalcidol and Ca). During the 2-year-study we observed the significantly highest lumbar spine and hip BMD increases in the combined treatment group (p < 0.001). The number of patients with new vertebral and non-vertebral fractures after 2 years was 9 with alfacalcidol alone, 10 with alfacalcidol and plain vitamin D and 2 in the group receiving alendronate plus alfacalidol (p < 0.02). Furthermore there was a lower rate of falls and an earlier reduction in back pain in the patients treated with the active combination. This trial confirms the demonstrated highly significant advantages of this combined treatment regimen used in the pilote studies. Especially in patients with severe osteoporosis this interesting combination of two substances with complete different mechanisms of action should be taken into consideration.

Back pain in osteoporotic vertebral fractures

This review article examines the epidemiology and pathogenesis of back pain and vertebral fractures in osteoporosis, reviewing the management of pain in patients with vertebral fractures and the direct and indirect effect of osteoporosis treatments on back pain.

INTRODUCTION

The management of patients with vertebral fractures has largely concentrated on the prevention of further fractures by the treatment of underlying osteoporosis, with drug treatment for acute and chronic back pain and the non-pharmacological management of vertebral fractures receiving less attention.

DISCUSSION

Emerging evidence suggests that, in addition to reducing the incidence of vertebral fractures, calcitonin, intravenous bisphosphonates and teriparatide may also have a direct effect on bone pain. Targeted analgesia, tailored to individual need is often required in both the acute and chronic phases following vertebral fracture. Vertebroplasty and kyphoplasty have also been approved for use in the management of vertebral fractures and may prove useful in selected patients unresponsive to conventional pain relief. There is some evidence to support the use of individualised tailored exercise programmes aimed at strengthening back muscles to maintain bone density and reduce further fracture incidence. In addition the use of specific orthoses may help to reduce kyphosis, improve mobility and reduce pain.

CONCLUSION

Chronic back pain associated with vertebral fracture provides a great challenge to health care professionals and the patient. This demands a combination of options, including not only therapeutic interventions, but also physiotherapy, psychological support and patient education.

Improving the outcome of established therapies for osteoporosis by adding the active D-hormone analog alfacalcidol

While in other chronic diseases combined treatment regimens are the rule there is a lack of reported experience or study data on combining different specific drugs to treat osteoporosis. Significant differences in the mode of action (MOA) of the substances to be combined may be important for achieving optimal therapeutic results. Recognising that today bisphosphonates are the leading therapy for osteoporosis we suggest that the active D-hormone analog alfacalcidol with its completely different mechanisms of action could be an interesting combination to improve the therapeutic outcome of the pure antiresoptive action of bisphosphonates. Alfacalcidol is activated by the enzyme 25-hydroxylase in the liver for systemic and in osteoblasts for local D-hormone actions. It possesses a unique pattern of pleiotropic effects on, e.g. gut, bone, pararthyroids, muscle and brain. Alfacalcidol is superior to plain vitamin D (cholecalciferol) because the final kidney activation of the latter is regulated by a negative feedback mechanism. In vitamin D replete patients or patients with impaired kidney function no increased D-hormone action at the target tissues can be achieved. Animal studies and several trials in humans with alendronate plus calcitriol or alfacalcidol proved that the combination induced significantly higher increases of bone mineral density (BMD) than the respective mono-therapies. The results of the 2-year AAC-trial from our group indicate that the combination alendronate and alfacalcidol is also superior in terms of falls, fractures and back pain. From the review of the literature and the own new results we conclude that this combined therapeutic regimen is a very promising option for treating established osteoporosis and propose a differentiated use of alfacalcidol alone or the combination with alendronate in different stages and clinical situations of osteoporosis.

[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.

Prevention and treatment of glucocorticoid-induced osteoporosis

Glucocorticoids continue to be used for many inflammatory diseases, and glucocorticoid-induced osteoporosis (GIOP) remains the most common secondary form of metabolic bone disease. Recent meta-analyses suggest that both active and native vitamin D can help maintain lumbar spine bone mineral density (BMD), particularly in patients receiving lower-dose glucocorticoid therapy. Recent randomized, controlled clinical trials have shown that oral bisphosphonates are superior to vitamin D in maintaining BMD and should be continued for as long as a person receives glucocorticoid treatment. Similar to the oral bisphosphonates, intravenous ibandronate has been shown to preserve BMD and also to significantly reduce vertebral fracture risk. Increasing evidence supports a role for parathyroid hormone to prevent or treat GIOP as well. Despite effective therapies, many at-risk patients fail to receive treatment for GIOP, and even among those who initiate treatment, half discontinue within 1 to 2 years. New approaches to evidence implementation are being tested to improve the quality of osteoporosis care and decrease fracture risk among long-term glucocorticoid users.

Superiority of alfacalcidol compared to vitamin D plus calcium in lumbar bone mineral density in postmenopausal osteoporosis

In a randomized multicenter, double-blind, double-dummy, parallel group study a comparison of the efficacy and safety of 1 microg alfacalcidol to 880 IU vitamin D plus calcium carbonate (1 g calcium) once daily per os was performed on 148 postmenopausal osteoporotic Caucasian patients with normal vitamin D serum levels for 18 months. Bone mineral density (BMD) was measured at baseline, 12 and 18 months. Safety parameters were followed during the entire study period. Sixty-nine (90.8%) in the alfacalcidol group and 67 (93.1%) in the vitamin D group were included in the ITT analysis. Lumbar BMD in the alfacalcidol group increased by 0.017 g/cm2 (2.33%) and 0.021 g/cm2 (2.87%) from baseline (P<0.001) at 12 and 18 months, respectively, whereas in the vitamin D plus calcium group the increase was 0.005 g/cm2 (0.70%) from baseline (N.S.) at both 12 and 18 months. The higher changes from baseline in the alfacalcidol group, as compared to the changes in the vitamin D plus calcium group at both 12 and 18 months, were found to be statistically significant (P=0.018, 0.005). A small increase of mean femoral BMD was achieved in both groups (N.S.). Adverse events were similar in both groups. No significant differences were noted between the groups in serum calcium. In conclusion, alfacalcidol was found to be superior in significantly increasing lumbar BMD as compared to vitamin D plus calcium while safety characteristics were found to be similar in both treatments.

Prevention and therapy of osteoporosis: the roles of plain vitamin D and alfacalcidol

Severe vitamin D deficiency was identified only in the first decades of the last century as the most common aetiology of rickets in children and osteomalacia in adults. It was later shown that vitamin D is not, as had been supposed, the biologically active principle for healing bone disease but must be hydroxylated in the liver and then finally in the kidney to become 1alpha,25-dihydroxy-cholecalciferol, a biologically highly active renal hormone. This study reviews the various principles, mechanisms, and approaches to the treatment of different forms of osteoporosis using vitamin D, alfacalcidol, and calcitriol therapy regimens.