Corticosteroid-induced bone loss. Prevention and management

Beneath the Surface: Exploring Hidden Threats of Long-Term Corticosteroid Therapy to Bone Density

Within the field of medical treatments, corticosteroids are potent substances that efficiently reduce inflammation and immunological responses, making them essential for the management of a wide range of medical ailments. However, continued use of these synthetic drugs presents a serious risk: the onset of osteoporosis brought on by corticosteroids. Determining the complex pathways by which corticosteroids cause a general disturbance in bone metabolism, suppress osteoblast function, increase osteoclast activity, and upset the delicate balance of bone remodelling emphasizes the need for all-encompassing management and prevention approaches. In this review, we aim to expose the complexities of corticosteroid-induced bone loss and urge for personalized, proactive measures to improve long-term therapeutic outcomes.

Public awareness of side effects of systemic steroids in Asir region, Saudi Arabia

Background

Corticosteroids have been used since the 50s and it represent the most important and frequently used class of anti-inflammatory and immunosuppressive drugs for the treatment of several diseases such as numerous neoplastic, asthma, allergy, rheumatoid arthritis, and dermatological disorders. This study aims to determine the public awareness of side effects of systemic steroids in Asir region, Saudi Arabia.

Methods

A descriptive cross-sectional web-based study was used. An online questionnaire was developed by the study researchers based on the literature review and consultations of the field experts. The questionnaire included the following components: Participants demographic data, medical history, and steroids use. Also, it covered participants awareness regarding systemic steroids and side effects.

Results

A total of 439 participants fulfilling the inclusion criteria completed the study questionnaire. Ages ranged from 18 to 65 years with mean age of 26.1 ± 13.9 years old, of those, 227 (51.7%) respondents were males. Around 346 (78.8%) had poor overall awareness level while only 93 (21.2%) had good awareness regarding systematic steroids. The study also showed that awareness was significantly higher among young aged participants in the health care field and among those who previously used steroids. Two hundred and eighty two (64.2%) of the respondents reported previous use of steroids.

Conclusion

In conclusion, the current study showed that nearly one out of each five people know about systemic steroids and related side effects which is below the satisfactory level. Higher awareness was observed with regards drug associated side effects and long-term use consequences.

Comparison of clinical outcome of lumbar spinal stenosis surgery in patients with and without osteoporosis: a prospective cohort study

BACKGROUND

Osteoporosis is one of the most important risk factors for failure of the spine instrumentation. Management of patients with osteoporosis who requires spinal surgery because of the difficulty in instrument placement and the potential complications is still a challenge. This study was designed to evaluate the clinical outcome of lumbar spinal canal stenosis after instrumentation in patients with and without osteoporosis.

METHODS

This prospective cohort study was performed from June 2018 to December 2020, in Be'sat Hospital, Hamadan, Iran. The sample consisted of patients over 50 years old referred to Be'sat Hospital with a diagnosis of lumbar spinal canal stenosis who underwent instrumental surgery (n = 107). Based on bone densitometry, the sample was divided into two groups with osteoporosis (n = 34) and without osteoporosis (n = 73). To collect data, we used a three-part researcher-made questionnaire (demographic information, medical records information, and paraclinical parameters). Statistical analyzes were performed by the Fisher Exact, chi-square, independent t-test, Multiple ANCOVA, Mann-Whitney and the Rank Wilcoxson tests using Stata version 17 software.

RESULTS

The mean age (SD) of patients in the two groups with and without osteoporosis was 67.9 (7.0) and 59.1 (5.1) years, respectively (p = 0.001). The results indicated that a significant difference was observed between the two groups in sex (p = 0.032), educational status (p = 0.001), marital status (p = 0.023), employment status (p = 0.004), menopausal status (p = 0.018), taking corticosteroids (p = 0.028), and body mass index (p = 0.015). Also, there was a significant difference between two groups in the loosening of instrument (p = 0.039), the postoperative pain intensity (p = 0.007), fusion (p = 0.047), and neurogenic claudication (p = 0.003). Based on multiple ANCOVA test, there was not a significant difference between two groups in the clinical and paraclinical charatecristics (p > 0.05). The mean (SD) of T-Score in the osteoporosis group was 3.06 (0.37).

CONCLUSION

This study provides evidence that there is no significant difference in the clinical outcomes of lumbar spine instrumentation due to spinal canal stenosis in patients with and without osteoporosis. Because of the high cost of specific instrumentation developed for patients with osteoporosis and their unavailability, it seems that the use of conventional instrumentation along with complete treatment of osteoporosis can help improve the clinical outcome of surgery in these patients.

Osteoporosis in Patients With Respiratory Diseases

Climate change, environmental pollution, and virus epidemics have sharply increased the number of patients suffering from respiratory diseases in recent years. Prolonged periods of illness and drug use increase the occurrence of complications in these patients. Osteoporosis is the common bone metabolism disease with respiratory disturbance, which affects prognosis and increases mortality of patients. The problem of osteoporosis in patients with respiratory diseases needs more attention. In this review, we concluded the characteristics of osteoporosis in some respiratory diseases including COPD, asthma, COVID-19, tuberculosis, and lung cancer. We revealed that hypoxia was the common pathogenesis of osteoporosis secondary to respiratory diseases, with malnutrition and corticosteroid abuse driving the progression of osteoporosis. Hypoxia-induced ROS accumulation and activated HIF-1α lead to attenuated osteogenesis and enhanced osteoclastogenesis in patients with respiratory diseases. Tuberculosis and cancer also invaded bone tissue and reduced bone strength by direct infiltration. For the treatment of osteoporosis in respiratory patients, oral-optimized bisphosphonates were the best treatment modality. Vitamin D was a necessary supplement, both for calcium absorption in osteogenesis and for improvement of respiratory lesions. Reasonable adjustment of the dose and course of corticosteroids according to the etiology and condition of patients is beneficial to prevent the occurrence and development of osteoporosis. Additionally, HIF-1α was a potential target for the treatment of osteoporosis in respiratory patients, which could be activated under hypoxia condition and involved in the process of bone remodeling.

Causal Association Between Tea Consumption and Bone Health: A Mendelian Randomization Study

Background

Much observational research reported that tea consumption decreases the risk of osteoarthritis (OA), rheumatoid arthritis (RA), and osteoporosis (OP) which are the three major bone disorders. However, the observed correlation is inconclusive. To determine the causal relationship between genetically predicted tea intake and OA, RA, and OP, we performed a two-sample Mendelian randomization (MR) study based on large samples.

Methods

The European population's genome-wide association meta-analysis (GWAS) dataset identified SNPs associated with tea consumption was obtained from Neale Lab's analysis of UK Biobank data that comprised 349,376 participants of European ancestry. We extracted genetic data for knee OA (17,885 controls and 4,462 cases), hip OA (50,898 controls and 12,625 cases), and RA (43,923 controls and 14,361 cases) from the UK Biobank and OP cases (93083 controls and 1,175 cases) from FinnGen Data Freeze 2. A MR study was conducted to examine the effect of selected single nucleotide polymorphisms (SNPs) and OA, RA, and OP risk. Several sensitivity analyses were performed with weighted median and inverse-variance weighted methods for estimating the causal effects.

Results

In this MR study, the genetically predicted per one cup increase of tea consumption was not associated with knee OA (OR 1.11,95% CI: 0.79-1.55) using IVW with random effect. Genetic predisposition to tea consumption was not associated with hip OA (OR: 1.20, 95% CI: 0.84-1.71), RA (OR: 1.24 95% CI: 0.81-1.91), and OP (OR: 1.11, 95% CI: 0.89, 1.39). Following the sensitivity analysis, there was no potential pleiotropy.

Conclusion

According to our study, According to our study, there was no statistical power to confirm a causal relationship between tea consumption and the risk of knee OA, hip OA, RA, and OP.

Aberrant RhoA activation in macrophages increases senescence-associated secretory phenotypes and ectopic calcification in muscular dystrophic mice

Duchenne Muscular Dystrophy (DMD) patients often suffer from both muscle wasting and osteoporosis. Our previous studies have revealed reduced regeneration potential in skeletal muscle and bone, concomitant with ectopic calcification of soft tissues in double knockout (dKO, dystrophin-/-; utrophin-/-) mice, a severe murine model for DMD. We found significant involvement of RhoA/ROCK (Rho-Associated Protein Kinase) signaling in mediating ectopic calcification of muscles in dKO mice. However, the cellular identity of these RhoA+ cells, and the role that RhoA plays in the chronic inflammation-associated pathologies has not been elucidated. Here, we report that CD68+ macrophages are highly prevalent at the sites of ectopic calcification of dKO mice, and that these macrophages highly express RhoA. Macrophages from dKO mice feature a shift towards a more pro-inflammatory M1 polarization and an increased expression of various senescence-associated secretory phenotype (SASP) factors that was reduced with the RhoA/ROCK inhibitor Y-27632. Further, systemic inhibition of RhoA activity in dKO mice led to reduced number of RhoA+/CD68+ cells, as well as a reduction in fibrosis and ectopic calcification. Together, these data revealed that RhoA signaling may be a key regulator of imbalanced mineralization in the dystrophic musculoskeletal system and consequently a therapeutic target for the treatment of DMD or other related muscle dystrophies.

Association of bullous pemphigoid and comorbid health conditions: a case-control study

BACKGROUND

Bullous pemphigoid is an autoimmune skin disease characterized by the formation of blisters between the epidermis and dermis. Comorbidities of pemphigoid have not been well-described. Identification of comorbidities associated with pemphigoid is important to decrease morbidity and mortality.

OBJECTIVE

To identify the comorbid health conditions of bullous pemphigoid.

METHODS

This was a case-control study of 91 cases of pemphigoid verified by clinical and laboratory diagnosis and 546 age- and sex-matched controls with complete follow-up at a large metropolitan quaternary care medical center.

RESULTS

The average age of bullous pemphigoid patients was 76 years and 53% of patients were female. Forty-eight (53%) of the BP patients had a history of inpatient hospitalization, of which 22 (24.2%) were hospitalized for either previously undiagnosed BP or an exacerbation of BP. Bullous pemphigoid was significantly associated with hypertension [adjusted odds ratio (95% confidence interval)]: [2.03 (1.24-3.32)], diabetes mellitus [2.59 (1.60-4.19)], chronic kidney disease [2.29 (1.19-4.40)], end-stage renal disease [3.82 (1.48-9.85)], basal cell carcinoma of the skin [6.00 (1.94-18.6)], and obstructive sleep apnea [5.23 (2.45-11.19)]. 78% of BP patients used at least one systemic immunosuppressant. There was no significant association between treatments for pemphigoid and any of the comorbidities.

CONCLUSIONS

Bullous pemphigoid patients need screening for comorbid health conditions even though treatment options do not seem to be associated with these comorbidities.

DSS-induced colitis produces inflammation-induced bone loss while irisin treatment mitigates the inflammatory state in both gut and bone

Chronic pediatric inflammatory bowel disease (IBD) leads to lack of bone accrual, bone loss, and increased fractures. Presently there is no cure, and many IBD treatments incur negative side effects. We previously discovered treatment with exogenous irisin resolved inflammatory changes in the colon, gut lymphatics, and bone in a mild IBD rodent model. Here we assess irisin treatment in severe IBD induced via dextran sodium sulfate (DSS). Male Sprague Dawley rats (2-mo-old) were untreated (Con) or given 2% DSS in drinking water. In week two, half of each group (Con + Ir and DSS + Ir) received injections of recombinant irisin (i.p., 2x/wk). After 4 weeks, gut inflammation was associated with declines in bone mineral density and cancellous bone volume. Furthermore, elevated osteocyte TNF-α, interleukin-6, RANKL, OPG, and sclerostin corresponded with higher osteoclast surfaces and lower bone formation rate in DSS animals as well as lower ultimate load. While irisin treatment improved colon inflammation, there were no improvements in bone density or bone mechanical properties; however, irisin elevated bone formation rate, decreased osteoclast surfaces, and reduced osteocyte pro-inflammatory factors. These data highlight the negative impact of chronic gut inflammation on bone as well as the therapeutic potential of irisin as an anti-inflammatory treatment.

Prevalence of Risk Factors Among Women With Osteoporosis

Osteoporosis is a progressive bone disorder that can be influenced by many different factors. A cross-sectional study has been conducted with the aim to assess the prevalence of risk factors as well as to identify the possible causes of improvement of the disease. Th e study population consisted of 97 women older than 35 who had previously been diagnosed with osteoporosis. Dualenergy X-ray Absorptiometry (DXA) scan was used to determine bone mineral density (BMD) in order to assess the current state of the disease. Th e participants were asked to complete a standardized IOF (International Osteoporosis Foundation) questionnaire. According to BMD measurements, 24.7% of women had normal bone density while 18.6% had T-score lower than -2.5. Th ere was a statistically significant correlation between T-score and the history of previous bone fractures. Besides, a relatively high prevalence of certain risk factors (such as underweight, early menopause, oophorectomy, thyroid and parathyroid disorders etc.) was observed in woman with osteoporosis

Access to Preventive Health Care in Severely Disabled Women with Multiple Sclerosis

BACKGROUND

Nonambulatory patients may be at risk for poor access to preventive health screening. Few studies have reported on this access in severely disabled women with multiple sclerosis (MS). We sought to describe preventive medical care in the most disabled women with MS and to identify factors that may influence access to care.

METHODS

Patient records from the Partners MS Center database were reviewed. Women with Expanded Disability Status Scale scores of 7 or greater were selected. Proportions of patients with preventive-care visits were compared with 2012 Centers for Disease Control and Prevention (CDC) guidelines and normative data. Logistic regression was used to assess demographic and disease effects on receiving services.

RESULTS

Forty-eight percent of patients had annual mammograms versus 72% of healthy women and the CDC target of 81%; 41.8% had Papanicolaou smears within 3 years compared with 82% of healthy women and the target of 93%; and 61.2% aged 50 years and older ever had a colonoscopy compared with the target of 70%. Younger age predicted lower rates of colonoscopy (P < .002) and mammography (P < .004), and shorter disease duration predicted lower rates of mammography (P < .004). Obesity was associated with a lower likelihood of colonoscopy (P = .007) and bone density screening (P = .02).

CONCLUSIONS

Women with severe MS disability are vulnerable to significantly decreased access to preventive care. The influence of patient and physician factors and the possible consequent delays in cancer diagnosis should be further clarified.

Efficacy and durability of the titanium mesh cage spacer combined with transarticular screw fixation for atlantoaxial instability in rheumatoid arthritis patients

STUDY DESIGN

A retrospective study.

OBJECTIVE

This retrospective investigation was conducted to determine efficacy and endurance of titanium mesh cage as a strut for interlaminar wiring by comparing with autologous iliac bone graft (AIBG). For patients with atlantoaxial instability (AAI), allograft bone was harvested on an interlaminar mesh cage and transarticular fixation (TAF) was performed.

SUMMARY OF BACKGROUND DATA

There have been few studies about atlantoaxial fusion rate and advantages for titanium mesh cage from comparison with AIBG in rheumatoid arthritis (RA) patients.

METHODS

Between January 1998 and October 2007, 55 RA patients were surgically treated for AAI. Among them, 34 patients who underwent surgical treatment with TAF and interlaminar wiring using mesh cage packed with allograft, enrolled in this study (group I). For evaluation of bone fusion about mesh cage group, 21 RA patients who underwent TAF and interlaminar wiring with AIBG were also selected (group II). In both groups, radiologic evidence of bone fusion was assessed with measuring atlantodental interval. Patients were strongly encouraged to mobilize by postoperative 1 day with external cervical bracing. The mean follow-up period was 12.3 months (6-36 months).

RESULTS

Overall, bone fusion was achieved in 33 patients (97%) in group I. And, this was comparable with 100% of group II. There was no statistical difference in bone fusion rate. During the study period, there were 2 instrument-related complications of screw malposition and cable loosening.

CONCLUSION

The results of this study in which mesh cage was used as an interlaminar spacer, showed immediate rigid fixation and successful bone union. We also could prevent donor site morbidities frequently seen in patients with surgical treatment for AAI.

Osteoporosis in pediatric patients suffering from chronic inflammatory bowel disease with and without steroid treatment

BACKGROUND

Children and adolescents suffering from inflammatory bowel disease (IBD) are at risk of developing osteoporosis as a result of treatment with corticosteroids as well as of nonsteroidal factors like inflammation and malnutrition. To study the impact of these factors on development of osteopathy, we compared the rate of osteoporosis in steroid-naive and steroid-treated pediatric IBD patients.

METHODS

In 90 patients (50 girls) with IBD (34 steroid-naive, 53 steroid-treated, 3 not known) aged 8.8 to 19.2 (14.4 +/- 2.2) years and 52 controls (27 girls) aged 6.1 to 17.6 (12.9 +/- 3.0) years, bone mineral density (BMD) of the lumbar spine was assessed with dual energy x-ray absorptiometry. Areal BMD values were transformed into volumetric densities called bone mineral apparent density (BMAD) and expressed as standard deviation scores (SDS) on the basis of the BMAD values of the controls.

RESULTS

The rate of osteoporotic patients (BMAD-SDS < -2) was 8% in girls and 20% in boys. There was a similar proportion of osteoporosis in steroid-naive (12%) and steroid-treated (11%) patients. SDS of body height showed a significant positive correlation with BMD-SDS but not with BMAD-SDS in almost all patient subgroups, indicating an interfering dependency of BMD from bone size.

CONCLUSIONS

The prevalence of osteoporosis in pediatric patients with IBD is approximately the same as in adult patients. Osteoporosis is already present before steroid treatment. Data of dual energy x-ray absorptiometry measurements should be transformed into volumetric parameters to compensate for short stature. Otherwise, a lot of growth-stunted patients may be falsely diagnosed as osteopenic.

Skeletal morbidity in inflammatory bowel disease

Patients with Crohn's disease are at increased risk of developing disturbances in bone and mineral metabolism because of several factors, including the cytokine-mediated nature of the inflammatory bowel disease, the intestinal malabsorption resulting from disease activity or from extensive intestinal resection and the use of glucucorticoids to control disease activity. Inability to achieve peak bone mass when the disease starts in childhood, malnutrition, immobilization, low BMI, smoking and hypogonadism may also play a contributing role in the pathogenesis of bone loss. The relationship between long-term use of glucocorticoids for any disease indication and increased risk for osteoporosis and fractures is well established. However, the relationship between Crohn's disease and ulcerative colitis and bone loss remains controversial. Depending on the population studied the prevalence of osteoporosis has thus been variably reported to range from 12 to 42% in patients with inflammatory bowel disease (IBD). In IBD most studies demonstrate a negative correlation between bone mineral density (BMD) and glucocorticoid use, but not all authors agree on the relationship between long-term glucocorticoid use and continuing bone loss. Whereas prospective studies do suggest sustained bone loss at both trabecular and cortical sites in long-term glucocorticoid users with inflammatory bowel disease, a decrease in bone mass is also observed in patients with active Crohn's disease not using glucocorticoids, and bone loss is not universally observed in patients with Crohn's disease using orally or rectally administered glucocorticoids. Data on vertebral fractures are scarce and there is no agreement about the risk of non-vertebral fractures in patients with Crohn's disease, although it has been suggested that non-vertebral fracture risk may be increased by up to 60% in patients with IBD. A recent publication reports an increased risk of hip fractures in Crohn's disease related to current and cumulative corticosteroid use and use of opiates, although these fractures could not be related to the severity of osteoporosis. The issue of the magnitude of the problem of osteoporosis has become particularly relevant in Crohn's disease, since the ability of therapeutic interventions to beneficially influence skeletal morbidity has been clearly established in patients with osteoporosis, whether post-menopausal women, men or glucocorticoid users. The main question that arises is whether all patients with Crohn's disease should be treated with bone protective agents on the assumption that they all have the potential to develop osteoporosis or whether the use of these agents should be restricted to patients clearly at risk of osteoporosis and fractures, providing these can be identified. We recommend, based on the available literature and our own experience, that all patients with Crohn's disease should be screened for osteoporosis by means of a bone mineral density measurement in addition to full correction of any potential calcium and vitamin D deficiency, to allow timely therapeutic intervention of the patient at risk while sparing the vast majority unnecessary medical treatment.

Case-Control Study Comparing the Efficacy of Surgical Techniques for C1???C2 Arthrodesis

Atlantoaxial fusion rates between 85% and 98% using C1-C2 transarticular screw (TAS) fixation have been reported; however, all of these studies are class III data. As such, these studies carry little or no statistical significance. The authors thus designed a case-control study (class II data) to evaluate the efficacy of C1-C2 TAS fixation as compared with posterior wiring techniques (PWTs). Records of adult subjects were reviewed for fusions isolated to C1-C2. Immobilization requirements were a collar for patients treated with TAS fixation and a halo for those treated by PWT. The minimum acceptable interval of radiographic follow-up was 12 months, and the outcome (fusion or nonunion) was determined through independent interpretation by a radiologist. Twenty-seven of 72 patients undergoing a posterior atlantoaxial arthrodesis met enrollment criteria. Sixteen males and 11 females combined for an average age of 54.1 years and mean follow-up of 31 months. Successful fusions (n = 18) were defined as controls, and cases represented nonunions (n = 9). Successful fusion was achieved in 13 of 14 patients treated with the TAS technique as compared with 5 of 13 subjects who underwent a PWT. Patients with a radiographically solid fusion were 21 more times likely to have undergone TAS than PWT (P = 0.004). This study demonstrated a statistically increased rate of arthrodesis as determined by specific radiographic criteria with the use of TAS fixation as compared with PWT.

Safety of inhaled corticosteroids in children

Inhaled corticosteroids (ICS) are now first-line therapy for persistent asthma in children. The major safety concerns of long-term ICS therapy for childhood asthma are potential effects on adrenal function, growth, and bone mass. Dosage, type of inhaler device, and individual drug characteristics influence systemic effects of ICS. Sensitive measures of basal adrenal function can show statistically significant changes during ICS therapy, but these do not accurately predict clinically meaningful adrenal axis suppression. Adrenal insufficiency is rare and confined to children receiving high doses of ICS. Dose-related inhibition of growth has been seen in some short- and intermediate-term studies, but long-term studies have found no detrimental effect on final height. ICS therapy has not been associated with significant changes in measurements of bone and bone biomarkers, but more studies of high doses and of therapy in adolescents are needed. Overall, although ICS are the most effective anti-inflammatory treatment available for asthma, high doses of ICS in children are still of concern. The risk of high doses is compounded in children with concomitant allergic conditions that require multiple forms of topical corticosteroids. Benefits of ICS clearly outweigh potential adverse effects and risks associated with poorly controlled asthma. Risk can be minimized by using the lowest effective ICS dose, limiting systemic availability of the drug through proper technique to minimize swallowed drug, and selection of agents with efficient first-path hepatic inactivation of swallowed drug. Adjuvant treatments can reduce the dose of ICS required for asthma control, allowing a reduction in overall systemic exposure for most children with mild-to-moderate persistent asthma. Therefore, these agents should be added to, but should not replace, ICS therapy.

Corticosteroid-Induced osteoporosis: detection and management

Corticosteroid-induced osteoporosis is a major cause of morbidity and is the leading secondary cause of osteoporosis today. Unfortunately, despite this knowledge, patients receiving corticosteroid therapy are often not offered any preventative treatment. Recent research has focused attention on the critical role the osteoblast has played in the pathophysiology of corticosteroid-induced osteoporosis. In addition to an initial increase in bone resorption, there is evidence that corticosteroids induce osteoblast and osteocyte apoptosis and as a result are important contributors to bone loss. Interesting work has suggested that the bisphosphonates and calcitonin may help to prevent osteoblast apoptosis from occurring. Large scale randomised controlled trials have also been completed with a variety of therapeutic agents. Of the many different therapies, it is now clear that the bisphosphonates have the greatest evidence to support their use. Increases in bone mineral density when compared with a control group, not only at the spine but also at the hip, have been demonstrated. These studies have shown clinically significant reductions in vertebral fracture rates seen for the most part in postmenopausal women. Other therapies may well be effective, as evidenced by maintenance of bone mass in the spine; however, maintenance of bone mass in the hip and reductions in fracture rate have yet to be demonstrated for many of these therapies. Given our current knowledge and the evidence that is outlined in this review, it is hoped that patients who require therapy with corticosteroids for more than 3 months will be offered appropriate preventative treatment.

Clinical considerations in the use of inhaled corticosteroids for asthma

Inhaled corticosteroids are the most potent and effective therapy for treating asthma. They exert their pharmacologic action through activation of the glucocorticoid receptor, which helps regulate gene transcription. Corticosteroids also directly inhibit several inflammatory mediators involved in the pathophysiology of asthma. In randomized, controlled clinical trials, inhaled corticosteroids, as monotherapy, are superior to other therapies in improving lung function and clinical outcomes in patients with asthma. However, the use of inhaled corticosteroids is limited by concerns of dose-related adverse effects, including growth suppression and decreased bone density. Combination regimens with these agents and other long-term therapies are beneficial in maintaining asthma control while minimizing dose-related toxicities. Several inhaled corticosteroid products are available in the United States. They differ in potency; however, clinical efficacy is similar when equipotent doses are administered. A variety of factors influence product selection and patient response, including the therapeutic ratio, pharmacokinetic properties, and the inhalation delivery device. In addition, adherence to therapy and the patient's skill in administering the inhaled drug contribute to the therapeutic outcome.

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.

Bone mineral density in women with asthma on long-term inhaled corticosteroid therapy

BACKGROUND

Inhaled corticosteroids (ICS) have become first line agents in the management of moderate-to-severe asthma. Long-term use of ICS is associated with decreased bone mineral density (BMD).

OBJECTIVE

To investigate the prevalence of BMD loss and its severity in women with asthma on long-term ICS.

METHODS

Fifty-six women with asthma on long-term ICS, attending an inner-city allergy clinic were selected to undergo bone densitometry in order to evaluate the association between BMD and the long-term use of ICS at different dose ranges.

RESULTS

Women (60.7%) had decreased BMD either at the lumbar spine or hip region. Among postmenopausal women, 17.1% of those <65 years and 42.9% of those > or =65 years had osteoporosis compared with 5.7% (95% CI-3.9% to 8.5%) of those <65 and 29.3% (95% CI-25.7%-33.5%) of those > or =65 years reported in the NHANES III survey. The prevalence of low BMD increased as ICS dose increased from 5% in the low dose group to 50% in the high dose group (P < .002). There were significant linear trends of decline by dose in mean BMD for the hip (P < .001) and the lumbar spine (P < .002). Women who received medium or high doses of ICS had significantly greater bone loss than those receiving low doses.

CONCLUSION

The findings of increasing BMD loss with increasing ICS dose reinforce the necessity to monitor BMD periodically in women on ICS, particularly in the high risk postmenopausal group and those on medium to high doses. There should be a concurrent continual attempt to lower the dose by supplemental nonsteroidal controller medications and providing nutritional and pharmacologic treatment of identified BMD loss in these patients.

Mycophenolate mofetil in stem cell transplant patients in relation to plasma level of active metabolite

OBJECTIVES

To investigate mycophenolate mofetil (MMF) plasma levels and impact on acute graft versus host disease (aGvHD) after stem cell transplantation (SCT).

METHODS

SCT patients (n = 14) with aGvHD (>/= II) receiving MMF (1-3 g/d) in addition to cyclosporine, prednisolone, and methotrexate for aGvHD prophylaxis were investigated. Plasma levels of mycophenolic acid (MPA) and its glucuronide metabolite (MPAG) were determined by high-performance liquid chromatography.

RESULTS

Overall median steady state pre-dose plasma MPA concentration was 0.47 mg/L and increased within 75 min after administration to 1.64 mg/L. In comparison to patients with skin aGvHD, patients with gut aGvHD had lower MPA concentrations, both pre-dose (p = 0.16) and after 75 min, (p = 0.02). All 7 patients with skin aGvHD but only 2 patients with gut aGvHD responded to MMF. Overall, the pre-dose plasma MPA concentration was significantly (p = 0.007) greater in responders (n = 9) than in non-responders (n = 5).

CONCLUSION

MMF seems to be an effective treatment for aGvHD in SCT patients particular in those patients without gut involvement.

Establishing a therapeutic index for the inhaled corticosteroids: part II. Comparisons of systemic activity and safety among different inhaled corticosteroids

The systemic activity and safety of inhaled corticosteroids are best studied in randomized, controlled, long-term trials with clinically relevant doses in subjects. These studies require large numbers of enrolled subjects and are difficult to conduct. Potential confounders to safety analyses must be controlled. The occurrence and magnitude of adrenal suppression has been the most extensively evaluated systemic effect of inhaled corticosteroids. The significance of these findings in relation to relevant clinical outcomes must be evaluated. At low to medium inhaled corticosteroid dosages, the hypothalamic-pituitary-adrenal axis is minimally and only partially suppressed. Statistically significant changes occur at high inhaled corticosteroid dosages; the magnitude of this effect is less than with prednisone, > or = 10 mg/day. Standards for the design of growth studies in children with asthma have been recommended and recently implemented. Four randomized, controlled, clinical trials have reported reductions in growth rates of > 1 cm/yr with beclomethasone < or = 400 microg/day. By comparison, 2 randomized controlled clinical trials with fluticasone, 50 to 100 microg twice daily via dry powder inhaler, could not detect differences in height velocity in prepubertal children treated with cromolyn sodium or placebo. Trials with low to medium doses of beclomethasone, fluticasone, and budesonide document little to no effect on bone mineral density and bone metabolism. Population-based and limited randomized controlled trials suggest that low to medium doses of inhaled corticosteroids do not cause cataracts or glaucoma. Patients requiring high-dose inhaled corticosteroids should be monitored for adverse effects, with appropriate lifestyle changes and pharmacologic strategies implemented.