Effect of intravenous pamidronate on bone mineral density in adults with cystic fibrosis

Bisphosphonates for osteoporosis in people with cystic fibrosis

BACKGROUND

Osteoporosis is a disorder of bone mineralisation occurring in about one third of adults with cystic fibrosis. Bisphosphonates can increase bone mineral density and decrease the risk of new fractures in post-menopausal women and people receiving long-term oral corticosteroids. This is an updated version of a previous review.

OBJECTIVES

To assess the effects of bisphosphonates on the frequency of fractures, bone mineral density, quality of life, adverse events, trial withdrawals, and survival in people with cystic fibrosis.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Trials Register of references (identified from electronic database searches and hand searches of journals and abstract books) on 5 May 2022. We performed additional searches of PubMed, clinicaltrials.gov and the WHO ICTRP (International Clinical Trials Registry Platform) on 5 May 2022.

SELECTION CRITERIA

Randomised controlled trials of at least six months duration studying bisphosphonates in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Authors independently selected trials, extracted data and assessed risk of bias in included studies. Trial investigators were contacted to obtain missing data. We judged the certainty of the evidence using GRADE.

MAIN RESULTS

We included nine trials with a total of 385 participants (272 adults and 113 children (aged five to 18 years)). Trial durations ranged from six months to two years. Only two of the studies were considered to have a low risk of bias for all the domains.  Bisphosphonates compared to control in people with cystic fibrosis who have not had a lung transplant Seven trials included only adult participants without lung transplants, one trial included both adults and children without lung transplantation (total of 238 adults and 113 children). We analysed adults (n = 238) and children (n = 113) separately. Adults Three trials assessed intravenous bisphosphonates (one assessed pamidronate and two assessed zoledronate) and five trials assessed oral bisphosphonates (one assessed risedronate and four assessed alendronate). Bisphosphonates were compared to either placebo or calcium (with or without additional vitamin D). Data showed no difference between treatment or control groups in new vertebral fractures at 12 months (odds ratio (OR) 0.22, 95% confidence interval (CI) 0.02 to 2.09; 5 trials, 142 participants; very low-certainty evidence) and two trials (44 participants) reported no vertebral fractures at 24 months. There was no difference in non-vertebral fractures at 12 months (OR 2.11, 95% CI 0.18 to 25.35; 4 trials, 95 participants; very low-certainty evidence) and again two trials (44 participants) reported no non-vertebral fractures at 24 months. There was no difference in total fractures between groups at 12 months (OR 0.57, 95% CI 0.13 to 2.50; 5 trials, 142 participants) and no fractures were reported in two trials (44 participants) at 24 months. At 12 months, bisphosphonates may increase bone mineral density at the lumbar spine (mean difference (MD) 6.31, 95% CI 5.39 to 7.22; 6 trials, 171 participants; low-certainty evidence) and at the hip or femur (MD 4.41, 95% 3.44 to 5.37; 5 trials, 155 participants; low-certainty evidence). There was no clear difference in quality of life scores at 12 months (1 trial, 47 participants; low-certainty evidence), but bisphosphonates probably led to more adverse events (bone pain) at 12 months (OR 8.49, 95% CI 3.20 to 22.56; 7 trials, 206 participants; moderate-certainty evidence). Children The single trial in 113 children compared oral alendronate to placebo. We graded all evidence as low certainty. At 12 months we found no difference between treatment and placebo in new vertebral fractures (OR 0.32, 95% CI 0.03 to 3.13; 1 trial, 113 participants) and non-vertebral fractures (OR 0.19, 95% CI 0.01 to 4.04; 1 trial, 113 participants). There was also no difference in total fractures (OR 0.18, 95% CI 0.02 to 1.61; 1 trial, 113 participants). Bisphosphonates may increase bone mineral density at the lumbar spine at 12 months (MD 14.50, 95% CI 12.91 to 16.09). There was no difference in bone or muscle pain (MD 3.00, 95% CI 0.12 to 75.22), fever (MD 3.00, 95% CI 0.12 to 75.22) or gastrointestinal adverse events (OR 0.67, 95% CI 0.20 to 2.26). The trial did not measure bone mineral density at the hip/femur or report on quality of life.  Bisphosphonates compared to control in people with cystic fibrosis who have had a lung transplant One trial of 34 adults who had undergone lung transplantation compared intravenous pamidronate to no bisphosphonate treatment. It did not report at 12 months and we report the 24-month data (not assessed by GRADE). There was no difference in the number of fractures, either vertebral or non-vertebral. However, bone mineral density increased with treatment at the lumbar spine (MD 6.20, 95% CI 4.28 to 8.12) and femur (MD 7.90, 95% CI 5.78 to 10.02). No participants in either group reported either bone pain or fever. The trial did not measure quality of life.

AUTHORS' CONCLUSIONS

Oral and intravenous bisphosphonates may increase bone mineral density in people with cystic fibrosis, but there are insufficient data to determine whether treatment reduces fractures. Severe bone pain and flu-like symptoms may occur with intravenous bisphosphonates. Before any firm conclusions can be drawn, trials in larger populations, including children, and of longer duration are needed to determine effects on fracture rate and survival. Additional trials are needed to determine if bone pain is more common or severe (or both) with the more potent zoledronate and if corticosteroids can ameliorate or prevent these adverse events. Future trials should also assess gastrointestinal adverse effects associated with oral bisphosphonates.

Treatment of cystic fibrosis related bone disease

The advent of highly effective CFTR modulator therapies has slowed the progression of pulmonary complications in people with cystic fibrosis. There is increased interest in cystic fibrosis bone disease (CFBD) due to the increasing longevity of people with cystic fibrosis. CFBD is a complex and multifactorial disease. CFBD is a result of hypomineralized bone leading to poor strength, structure and quality leading to susceptibility to fractures. The development of CFBD spans different age groups. The management must be tailored to each group with nuance and based on available guidelines while balancing therapeutic benefits to risks of long-term use of bone-active medication. For now, the mainstay of treatment includes bisphosphonates. However, the long-term effects of bisphosphonate treatment in people with CF are not fully understood. We describe newer agents available for osteoporosis treatment. Still, the lack of data behooves trials of monoclonal antibodies treatments such as Denosumab and Romozosumab and anabolic bone therapy such as teriparatide and Abaloparatide. In this review, we also summarize screening and non-pharmacologic treatment of CFBD and describe the various options available for the pharmacotherapy of CFBD. We address the prospect of CFTR modulators on bone health while awaiting long-term trials to describe the effects of these medications on bone health.

Cystic fibrosis bone disease treatment: Current knowledge and future directions

Bone disease is a frequent complication in adolescents and adults with cystic fibrosis (CF). Early detection and monitoring of bone mineral density and multidisciplinary preventive care are necessary from childhood through adolescence to minimize CF-related bone disease (CFBD) in adult CF patients. Approaches to optimizing bone health include ensuring adequate nutrition, particularly intake of calcium and vitamins D and K, addressing other secondary causes of low bone density such as hypogonadism, encouraging weight bearing exercise, and avoiding bone toxic medications. Of the currently available anti-resorptive or anabolic osteoporosis medications, only bisphosphonates have been studied in individuals with CF. Future studies are needed to better understand the optimal approach for managing CFBD.

Diagnosis and treatment of endocrine comorbidities in patients with cystic fibrosis

PURPOSE OF REVIEW

The aim of this review is to provide an update on various relevant endocrine aspects of care in adolescents and adults with cystic fibrosis.

RECENT FINDINGS

As life expectancy in cystic fibrosis has continuously improved, endocrine complications have become more apparent. The common endocrine complications include cystic fibrosis related diabetes, cystic fibrosis related bone disease, vitamin D deficiency and poor growth and pubertal development. Thyroid and adrenal disorders have also been reported, although the prevalence appears to be less common.

SUMMARY

Endocrine diseases are an increasingly recognized complication that has a significant impact on the overall health of individuals with cystic fibrosis. This review summarizes the updated screening and management of endocrine diseases in the cystic fibrosis population.

Bisphosphonates for osteoporosis in people with cystic fibrosis

BACKGROUND

Osteoporosis is a bone mineralisation disorder occurring in about one third of adults with cystic fibrosis. Bisphosphonates can increase bone mineral density and decrease the risk of new fractures in post-menopausal women and people receiving long-term oral corticosteroids.

OBJECTIVES

To assess the effects of bisphosphonates on the frequency of fractures, bone mineral density, quality of life, adverse events, trial withdrawals, and survival in people with cystic fibrosis.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group Trials Register of references (identified from electronic database searches and handsearches of journals and abstract books) on 13 January 2014.Additional searches of PubMed were performed on 13 January 2014.

SELECTION CRITERIA

Randomised controlled trials of at least six months duration studying bisphosphonates in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and extracted data. Trial investigators were contacted to obtain missing data.

MAIN RESULTS

Nine trials were identified and seven (with a total of 237 adult participants) were included.Data were combined (when available) from six included studies in participants without a lung transplant. Data showed that there was no significant reduction in fractures between treatment and control groups at 12 months, odds ratio 0.72 (95% confidence interval 0.13 to 3.80). No fractures were reported in studies with follow-up at 24 months. However, in patients taking bisphosphonates after six months the percentage change in bone mineral density increased at the lumbar spine, mean difference 4.61 (95% confidence interval 3.90 to 5.32) and at the hip or femur, mean difference 3.35 (95% confidence interval 1.63 to 5.07); but did not significantly change at the distal forearm, mean difference -0.49 (95% confidence interval -2.42 to 1.45). In patients taking bisphosphonates, at 12 months the percentage change in bone mineral density increased at the lumbar spine, mean difference 6.10 (95% confidence interval 5.10 to 7.10) and at the hip or femur, mean difference 4.35 (95% confidence interval 2.99 to 5.70). At 24 months, in patients treated with bisphosphonates the percentage change in bone mineral density also increased at the lumbar spine, mean difference 5.49 (95% confidence interval 4.38 to 6.60) and at the hip or femur, mean difference 6.05 (95% confidence interval 3.74 to 8.36). There was clinical heterogeneity between studies and not all studies reported all outcomes. Bone pain was the most common adverse event with intravenous agents. Flu-like symptoms were also increased in those taking bisphosphonates.In participants with a lung transplant (one study), intravenous pamidronate did not change the number of new fractures. At axial sites, bone mineral density increased with treatment compared to controls: percentage change in bone mineral density at lumbar spine, mean difference 6.20 (95% confidence interval 4.28 to 8.12); and femur mean difference 7.90 (95% confidence interval 5.78 to 10.02).

AUTHORS' CONCLUSIONS

Oral and intravenous bisphosphonates increase bone mineral density in people with cystic fibrosis. Severe bone pain and flu-like symptoms may occur with intravenous agents. Additional trials are needed to determine if bone pain is more common or severe (or both) with the more potent zoledronate and if corticosteroids ameliorate or prevent these adverse events. Additional trials are also required to further assess gastrointestinal adverse effects associated with oral bisphosphonates. Trials in larger populations are needed to determine effects on fracture rate and survival.

Evaluation of teriparatide for treatment of osteoporosis in four patients with cystic fibrosis: a case series

Introduction. Bone disease is a common complication of cystic fibrosis (CF). To date, there have been no reports on the effectiveness of teriparatide, recombinant human parathyroid hormone, to treat CF-related bone disease. Case Presentation. We report on four patients with CF-related bone disease who were treated with teriparatide. Three patients completed two years of therapy with teriparatide, and all had significant improvements in their bone mineral density (BMD). One patient was unable to tolerate teriparatide and discontinued treatment 1 week into therapy. Conclusion. Teriparatide may be a potential treatment option for CF-related bone disease. This report highlights the need for further investigation into the use of teripartide in the CF population.

Bisphosphonates use in children

Bisphosphonates are synthetic analogues of pyrophosphate that inhibit bone resorption by their action on osteoclasts. In recent years, bisphosphonates have been used in children for treatment of a growing number of disorders associated primarily with generalized or localized osteoporosis, genetic and acquired metabolic bone diseases, heterotopic calcifications in soft tissues, and for hypercalcemia. In this review, the authors address the role of and experience with bisphosphonate therapy in disorders of childhood.

Bisphosphonates for osteoporosis in people with cystic fibrosis

BACKGROUND

Osteoporosis is a bone mineralisation disorder occurring in about one third of adults with cystic fibrosis. Bisphosphonates can increase bone mineral density and decrease the risk of new fractures in post-menopausal women and people receiving long-term oral corticosteroids.

OBJECTIVES

To assess the effects of bisphosphonates on the frequency of fractures, bone mineral density, quality of life, adverse events, trial withdrawals, and survival in people with cystic fibrosis.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group Trials Register of references (identified from electronic database searches and handsearches of journals and abstract books) on 15 February 2012.Additional searches of PubMed were performed on 14 May 2011.

SELECTION CRITERIA

Randomised controlled trials of at least six months duration studying bisphosphonates in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and extracted data. Trial investigators were contacted to obtain missing data.

MAIN RESULTS

Nine trials were identified and seven (with a total of 237 adult participants) were included.Data were combined (when available) from six included studies in participants without a lung transplant. Data showed that there was no significant reduction in fractures between treatment and control groups at 12 months, odds ratio 0.72 (95% confidence interval 0.13 to 3.80). No fractures were reported in studies with follow-up at 24 months. However, in patients taking bisphosphonates after six months the percentage change in bone mineral density increased at the lumbar spine, mean difference 4.61 (95% confidence interval 3.90 to 5.32) and at the hip or femur, mean difference 3.35 (95% confidence interval 1.63 to 5.07); but did not significantly change at the distal forearm, mean difference -0.49 (95% confidence interval -2.42 to 1.45). In patients taking bisphosphonates, at 12 months the percentage change in bone mineral density increased at the lumbar spine, mean difference 6.10 (95% confidence interval 5.10 to 7.10) and at the hip or femur, mean difference 4.35 (95% confidence interval 2.99 to 5.70). At 24 months, in patients treated with bisphosphonates the percentage change in bone mineral density also increased at the lumbar spine, mean difference 5.49 (95% confidence interval 4.38 to 6.60) and at the hip or femur, mean difference 6.05 (95% confidence interval 3.74 to 8.36). There was clinical heterogeneity between studies and not all studies reported all outcomes. Bone pain was the most common adverse event with intravenous agents. Flu-like symptoms were also increased in those taking bisphosphonates.In participants with a lung transplant (one study), intravenous pamidronate did not change the number of new fractures. At axial sites, bone mineral density increased with treatment compared to controls: percentage change in bone mineral density at lumbar spine, mean difference 6.20 (95% confidence interval 4.28 to 8.12); and femur mean difference 7.90 (95% confidence interval 5.78 to 10.02).

AUTHORS' CONCLUSIONS

Oral and intravenous bisphosphonates increase bone mineral density in people with cystic fibrosis. Severe bone pain and flu-like symptoms may occur with intravenous agents. Additional trials are needed to determine if bone pain is more common or severe (or both) with the more potent zoledronate and if corticosteroids ameliorate or prevent these adverse events. Additional trials are also required to further assess gastrointestinal adverse effects associated with oral bisphosphonates. Trials in larger populations are needed to determine effects on fracture rate and survival.

'Old' bones in young bodies: the tale of cystic fibrosis

PURPOSE OF REVIEW

Cystic fibrosis (CF) is the most common genetic disease within the white population and leads to premature respiratory failure. Approximately, 60 000 individuals are currently living with CF in North America and Europe, almost half of whom are adults.

RECENT FINDINGS

Dozens of studies across the globe indicate that CF adults have low bone density and increased rates of fractures. This genesis of the problem appears to be in late childhood to adolescence.

SUMMARY

Prevention and treatment of CF-related bone disease must address the myriad risk factors (decreased absorption of fat-soluble vitamins due to pancreatic insufficiency, altered sex hormone production, chronic lung infection with increased serum levels of proinflammatory, bone-active cytokines, malnutrition and low body weight, physical inactivity and glucocorticoid therapy) for poor bone health. This review will address the pathogenesis, diagnosis and treatment of bone disease in CF. It will also discuss best practice guidelines for optimizing bone health in patients with CF.

Bisphosphonates for osteoporosis in people with cystic fibrosis

BACKGROUND

Osteoporosis is a bone mineralisation disorder occurring in about one third of adults with cystic fibrosis (CF). Bisphosphonates can increase bone mineral density (BMD) and decrease the risk of new fractures in post-menopausal women and people receiving long-term oral corticosteroids.

OBJECTIVES

To assess the effects of bisphosphonates on the frequency of fractures, BMD, quality of life, adverse events, trial withdrawals, and survival in people with CF.

SEARCH STRATEGY

We searched the CF and Genetic Disorders Group Trials Register of references (identified from electronic database searches and handsearches of journals and abstract books) on 29 October 2008.Additional searches of Pubmed were performed on 01 November 2008.

SELECTION CRITERIA

Randomised controlled trials of at least six months duration studying bisphosphonates in people with CF.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials and extracted data. Trial investigators were contacted to obtain missing data.

MAIN RESULTS

Seven trials were identified and five (with a total of 145 adult participants) were included.Data were combined when available from four included studies in participants without a lung transplant. This showed that there was no significant reduction in fractures between groups. However, after six months, the percentage change in BMD increased in those on bisphosphonates at the lumbar spine, mean difference (MD) 4.61 (95% confidence interval (CI) 3.90 to 5.32) and at the hip, MD 3.35 (95% CI 1.63 to 5.07); but did not significantly change at the distal forearm, MD -0.49 (95% CI -2.42-1.45). There was clinical heterogeneity between studies and not all studies reported all outcomes. Bone pain was the most common adverse event with intravenous agents. Flu-like symptoms were also increased in those taking bisphosphonates.In participants with a lung transplant (one study), intravenous pamidronate did not change the number of new fractures. At axial sites, BMD increased with treatment compared to controls: percentage change in bone mineral density at lumbar spine, MD 6.20 (95% CI 4.28 to 8.12) and femur MD 7.90 (95% CI 5.78 to 10.02).

AUTHORS' CONCLUSIONS

Oral and intravenous bisphosphonates increase BMD in people with CF. Severe bone pain and flu-like symptoms may occur with intravenous agents. Additional trials are needed to determine if bone pain is more common or severe (or both) with the more potent zoledronate and if corticosteroids ameliorate or prevent these adverse events. Trials in larger populations are needed to determine effects on fracture rate and survival.

Update on cystic fibrosis-related bone disease: a special focus on children

A high prevalence of low bone mineralization is documented in adult patients with cystic fibrosis (CF). Osteopenia is present in up to 85% of adult patients and osteoporosis in 10% to 34%. In children, study results are discordant probably because of comparisons to different control populations and corrections for bone size in growing children. Malnutrition, inflammation, vitamin D and vitamin K deficiency, altered sex hormone production, glucocorticoid therapy, and physical inactivity are well known risk factors for poor bone health. Puberty is a critical period for bone mineralization and requires a careful follow-up to achieve optimal bone peak mass. Strategies for optimizing bone health, such as monitoring bone mineral density (BMD) and providing preventive care are necessary from childhood through adolescence to minimize CF-related bone disease in adult CF patients.

Intravenous zoledronate improves bone density in adults with cystic fibrosis (CF)

OBJECTIVE

Reduced bone mineral density (BMD) and increased rates of atraumatic fracture are observed in cystic fibrosis (CF) patients, causing increasing morbidity as this population ages. The study aimed to assess the safety, tolerability and effect on BMD of intravenous zoledronate in adults with CF and osteopaenia.

DESIGN

Randomized, double-blind, placebo-controlled clinical trial.

SETTING

Adult CF outpatient clinics at two hospitals.

PATIENTS

Twenty-two non-transplanted CF patients aged > or = 18 years with a bone densitometry T-score of < -1.5 at one of three sites (lumbar spine, femoral neck, distal forearm) were studied. Participants were randomized to receive either 2 mg zoledronate i.v. (n = 10) or normal saline (placebo, n = 12) every 3 months for 2 years (8 infusions). All participants received calcium and vitamin D supplements twice daily.

MEASUREMENTS

Percentage change in areal BMD from baseline.

RESULTS

Lumbar spine BMD increased from baseline more with zoledronate than placebo at 6 months (5.35 +/- 0.76 vs. 1.19 +/- 1.20%, P = 0.012), 12 months (6.6 +/- 1.5 vs. 0.35 +/- 1.55%, P = 0.011) and 24 months (6.14 +/- 1.86 vs. 0.44 +/- 0.10, P = 0.021). Femoral neck BMD increased more after zoledronate than placebo at 6 months (3.2 +/- 1.6 vs.-1.43 +/- 0.43%, P = 0.019), 12 months (4.12 +/- 1.8 vs.-1.59 +/- 1.4%, P = 0.024) and 24 months (4.23 +/- 1.3 vs.-2.5 +/- 1.41%, P = 0.0028). Forearm BMD did not change. Zoledronate was associated with flu-like and musculoskeletal side effects, particularly after the first infusion. There were no fractures in either group.

CONCLUSION

Intravenous zoledronate was significantly more effective than placebo for increasing BMD in adults with CF and osteopaenia, but side effects limited its tolerability.

Alendronate once weekly for the prevention and treatment of bone loss in Canadian adult cystic fibrosis patients (CFOS trial)

BACKGROUND

Patients with cystic fibrosis (CF) are at risk for early bone loss, and demonstrate increased risks for vertebral fractures and kyphosis. A multicenter, randomized, controlled trial was conducted to assess the efficacy, tolerability, and safety of therapy with oral alendronate (FOSAMAX; Merck; Whitehouse Station, NJ) in adults with CF and low bone mass.

METHODS

Participants received placebo or alendronate, 70 mg once weekly, for 12 months. All participants received 800 IU of vitamin D and 1,000 mg of calcium daily. Adults with confirmed CF with a bone mineral density (BMD) T score of < - 1.0 were eligible for inclusion. Participants who had undergone organ transplantation or had other reported contraindications were excluded from the study. The primary outcome measure was the mean (+/- SD) percentage change in lumbar spine BMD after 12 months. Secondary measures included the percentage change in total hip BMD, the number of new vertebral fractures (grade 1 or 2), and changes in quality of life.

RESULTS

A total of 56 participants were enrolled in the study (mean age, 29.1 +/- 8.78 years; 61% male). The absolute percentage changes in lumbar spine and total hip BMDs at follow-up were significantly higher in the alendronate therapy group (5.20 +/- 3.67% and 2.14 +/- 3.32%, respectively) than those in the control group (- 0.08 +/- 3.93% and - 1.3 +/- 2.70%, respectively; p < 0.001). At follow-up, two participants (both in the control group) had a new vertebral fracture (not significant), and there were no differences in quality of life or the number of adverse events (including serious and GI-related events).

CONCLUSION

Alendronate therapy was well tolerated and produced a significantly greater increase in BMD over 12 months compared with placebo.

Exercise during childhood and adolescence: a prophylaxis against cystic fibrosis-related low bone mineral density? Exercise for bone health in children with cystic fibrosis

Inadequate bone mineral accrual during growth and accelerated bone demineralisation in adulthood are recognised as additional and serious complications for patients with cystic fibrosis (CF). However, little attention has been given to preventative strategies for this population. Inadequate bone accrual during childhood and adolescence, and premature bone loss, lead to a failure to attain an optimal peak bone mass, osteoporosis and fracture in patients with CF. Pharmaceutical treatments may assist in the improvement of bone in patients with CF, but these are usually not preferable for use in children. Evidence indicates that regular, weight-bearing exercise significantly enhances bone accrual in healthy children. This paper reviews the literature concerning the potential for weight-bearing exercise to improve bone mineral accrual in children with CF. All relevant literature since 1979 was obtained and reviewed from the Medline, PubMed, Cochrane and PEDro data base. Evidence concerning the efficacy of exercise for bone health in CF is lacking. There have been no controlled trials investigating the value of weight-bearing exercise for bone accrual in children with CF. As exercise may offer an effective and enjoyable strategy to improve the bone development in children who have CF, exercise should be a high priority for randomised controlled trials in this population.

Pediatric dual-energy X-ray absorptiometry: technique, interpretation, and clinical applications

This article reviews the dual-energy x-ray absorptiometry (DXA) technique, its interpretation, and clinical applications with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist," monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist," aware of the DXA findings in a large number of clinical diseases, providing the referring clinician with a meaningful context for the numeric result obtained with DXA.

Pediatric DXA: clinical applications

Normal bone mineral accrual requires adequate dietary intake of calcium, vitamin D and other nutrients; hepatic and renal activation of vitamin D; normal hormone levels (thyroid, parathyroid, reproductive and growth hormones); and neuromuscular functioning with sufficient stress upon the skeleton to induce bone deposition. The presence of genetic or acquired diseases and the therapies that are used to treat them can also impact bone health. Since the introduction of clinical DXA in pediatrics in the early 1990s, there has been considerable investigation into the causes of low bone mineral density (BMD) in children. Pediatricians have also become aware of the role adequate bone mass accrual in childhood has in preventing osteoporotic fractures in late adulthood. Additionally, the availability of medications to improve BMD has increased with the development of bisphosphonates. These factors have led to the increased utilization of DXA in pediatrics. This review summarizes much of the previous research regarding BMD in children and is meant to assist radiologists and clinicians with DXA utilization and interpretation.

Update on maintaining bone health in cystic fibrosis

PURPOSE OF REVIEW

The high prevalence of decreased bone density in adults with cystic fibrosis is now well recognized, and guidelines for screening and treatment of cystic fibrosis-related bone disease have recently been published. This review summarizes the current best practices for optimizing bone health in cystic fibrosis and highlight recent findings that provide insight into the etiology of cystic fibrosis-related bone disease.

RECENT FINDINGS

Recent research suggests that cystic fibrosis-related bone disease actually starts during childhood, when individuals with cystic fibrosis fail to demonstrate normal bone calcium accretion. The failure to reach peak bone mass is made worse by increased osteoclast activity and bone resorption. This combination results in decreased bone density and an increased risk of fracture. Recent clinical studies suggest that multiple contributing factors need to be addressed in cystic fibrosis to optimize bone health: malnutrition, vitamin and mineral malabsorption, recurrent infections, inadequate sex hormones, and lack of exercise. Oral bisphosphonates have been demonstrated to be effective in cystic fibrosis and should be used when osteoporosis or progressive osteopenia is present.

SUMMARY

Research suggests cystic fibrosis-related bone disease actually begins during childhood, and guidelines now exist to aid in identifying and treating those with decreased bone density.

Efectividad en la aplicación de tres protocolos de prevención y tratamiento de la osteoporosis en pacientes adultos con fibrosis quística

BACKGROUND AND OBJECTIVE

Reduction of bone mineral density (BMD) is a complication of cystic fibrosis (CF) which is observed in parallel to the increment of life expectancy in these patients. The aim of this study was to analyze the evolution of BMD following the application of a protocol for the prevention and treatment of osteoporosis.

PATIENTS AND METHOD

We performed a multidisciplinary prospective study in 21 adult patients with CF with a mean age of 24.3 (r: 19-44) years. We evaluated BMD results depending on the treatment schedule, and the annual relative change of BMD percentage was correlated with changes observed in respiratory function, corporal mass index (CMI), Brasfield radiologic score and Shwachman clinical score for a 3 years follow up period. Three regimens of treatment were applied: general measurements, supplementation of calcium and vitamin D, and 10 daily mg of alendronate plus calcium and vitamin D supplements.

RESULTS

Basal assessment showed that 14.2% of CF patients had a marked diminution of bone mass with respect to an age and sex matched control population, with a Z score of < -2 DE in lumbar vertebral and/or total femur. Another 38% showed a lessening of Z score between -1 and -2.5 DE. We observed a progressive annual reduction of BMD in all the anatomic areas analyzed: -0.52% (1.87) in lumbar spine, -1.17% (1.91) in total femur and -2.16% (2.65) in neck femur. The hip BMD annual decrement was related to that observed in FEV1. Only patients treated with alendronate did not suffer progressive BMD lose. Treatment with a combination of calcium, vitamin D and alendronate was more efficient in hip BMD than calcium plus vitamin D alone (p < 0.05). Also, this combination was better than no treatment at hip and femoral neck levels (p < 0.05).

CONCLUSIONS

Our work confirms that Spanish young adults patients with CF show low control matched BMD, and that it even worsens at follow-up. This decrement is not adequately halted with preventive treatment with supplements of calcium and vitamin D, and only patients treated with alendronate show increments of their BMD.

Efficacité des biphosphonates oraux sur la déminéralisation osseuse des patients atteints de mucoviscidose

Disturbances in bone mineralization are frequent in cystic fibrosis but few studies have focused on the use of biphosphonates in this indication, and none on the use of oral etidronate. We report our experience using this latter treatment.

METHODS

The study was retrospective and included five children and three adults with cystic fibrosis (six males and two females) aged seven to 30 years with Z-scores for lumbar bone density lower than -2 SD after one year of calcium (1 g/day) and vitamin D (900 UI/day and 300,000 UI/6 months) supplementation. All were treated during one year with etidronate: four courses of 15 days (one course per trimester) with doses ranging from 4 to 8 mg/kg per day. Calcium and vitamin D supplementation was continued between the etidronate treatment course. Total body and lumbar bone mineral density (BMD) were measured three times: at the beginning and the end of the year of calcium and vitamin D supplementation and at the end of the year of supplementation plus the four courses of etidronate treatment.

RESULTS

The increase in BMD in absolute value (g/cm2) and in Z-score was significantly higher (P <0.05) after the year of combined supplementation and etidronate treatment (total body g/cm2: 3+/-1%, Z-score: 2+/-1% and lumbar spine g/cm2: 6+/-5%, Z-score: 3+/-4%) than after supplementation alone (total body g/cm2: -1+/-3%, Z-score: -4+/-3% and lumbar spine g/cm2: -1+/-3%, Z-score: -4+/-4%). Supplementation alone improved the total BMD in only one patient and the lumbar BMD in three, whereas after etidronate treatment the total and lumbar BMD were improved in the eight patients. None of the patients presented with side effects that could be attributed to the treatment.

CONCLUSION

Oral etidronate treatment is well-tolerated and capable of improving bone mineralization in patients with cystic fibrosis. Further work will be necessary to determine the optimal dosage and the optimal frequency for the treatment series.

Randomised double blind placebo controlled trial investigating the effect of calcium and vitamin D supplementation on bone mineral density and bone metabolism in adult patients with cystic fibrosis

BACKGROUND

Low bone mineral density (BMD) is prevalent in adults with cystic fibrosis and might be related to calcium and vitamin D malabsorption from the gastrointestinal tract. The aim of this study was to investigate the effect of calcium and vitamin D supplementation on BMD and bone metabolism in these subjects.

METHODS

Patients were invited to participate if they had a BMD Z score of -1 or less in the lumbar spine, proximal femur or distal forearm. Patients were randomised to receive calcium 1 g+vitamin D 800 IU or placebo daily, in addition to their regular vitamin D supplements (900 IU/day). BMD and bone biochemical markers were measured before and after 1 year of treatment.

RESULTS

After 12 months, the treatment group (n=15) showed a reduced rate of bone loss compared with the control group (n=15) in the lumbar spine (mean difference 1.9% [CI -0.9% to 4.6%]), total hip (mean difference 0.7% [CI -2.2% to 3.5%]) and distal forearm (mean difference 1.7% [CI -2.2% to 5.5%]), but these changes did not reach statistical significance. There was also a trend towards a reduction in bone turnover in the treatment group.

CONCLUSIONS

Calcium and vitamin D supplementation reduced the rate of bone turnover and bone loss in adult patients with cystic fibrosis, but these changes did not reach statistical significance. These data suggest that a longer term trial of this simple intervention would be justified.

Treatment of bone disease in cystic fibrosis

PURPOSE OF REVIEW

As individuals with cystic fibrosis (CF) have experienced marked improvements in longevity over the last three decades, bone disease has emerged as a new problem. Bone disease in CF has not been previously reviewed in this journal. Therefore, this review will give a brief overview of bone disease in CF and then concentrate on treatment options.

RECENT FINDINGS

In some series, as many as three fourths of adults with CF have low bone density. Decreased absorption of fat-soluble vitamins due to pancreatic insufficiency, altered sex hormone production, chronic inflammation, physical inactivity, and glucocorticoid treatment are some of the factors that contribute to this problem. Vitamin D depletion most likely contributes to bone disease, but identifying the safest and most efficacious vitamin D supplementation has yet to be resolved. Calcium and vitamin K supplementations are important if the diet contains less than the recommended amounts. Treatment of delayed puberty and adult hypogonadism with hormone replacement is recommended to achieve peak bone mass and maintain bone density. Bisphosphonates, including pamidronate and alendronate, are beneficial in improving bone mineral density before and after transplantation in CF adults. Bisphosphonates have not been studied in CF children.

SUMMARY

Although much progress has been made in our understanding of the pathogenesis, natural history, and clinical manifestations of bone disease in CF, treatment options are still evolving. More attention to nutrition, in terms of the maintenance of lean body mass and vitamin D and calcium supplementation, is likely to decrease bone complications. Bisphosphonates can be of value in CF adults with low bone density. Several clinical trials are under way to help optimize the treatment of CF bone disease.

Effect of oral bisphosphonates on bone mineral density and body composition in adult patients with cystic fibrosis: a pilot study

BACKGROUND

Approximately two thirds of adult patients with cystic fibrosis have reduced bone mineral density and up to one quarter have osteoporosis at one or more sites. Any bone mineral deficits are likely to be exacerbated in patients following lung transplantation by their immunosuppressive regimen. Vertebral collapse and rib fractures will impair the ability to cough and the efficacy of physiotherapy treatments.

METHODS

Patients attending the Leeds Regional Adult Cystic Fibrosis Unit with either osteopenia or osteoporosis on dual energy x ray absorptiometry (DXA) scanning were offered treatment with oral bisphosphonates after exclusion of abnormal vitamin D, calcium, or phosphate levels, abnormal thyroid function, or hypogonadism. Those declining treatment or patients with a normal initial DXA scan formed the control group. A second DXA scan was performed after a mean of 2.4 years in the treatment group and 2.9 years in the non-treatment group. Patients in the active group were asked to complete a short questionnaire detailing their adherence to treatment.

RESULTS

The medians of the differences in annual changes in bone parameters between treatment and control groups showed significant differences in bone mineralisation in favour of the treatment group at the lumbar spine (L2-L4), the femoral neck, and for total body measurements. There were no significant differences in weight, height, or body composition in either patient group. Most treated patients stated that they adhered to treatment most of the time.

CONCLUSION

Treatment with oral bisphosphonates may improve bone mineralisation in adult patients with cystic fibrosis. The results of this pilot study need to be further explored in a randomised controlled trial.

Estudio de la densidad mineral ósea en pacientes adultos con fibrosis quística

BACKGROUND AND OBJECTIVE

Due to recent medical advances, patients with cystic fibrosis (CF) can expect longer survival rates and, as a result, face previously unreported complications such as osteoporosis. Our goal was to determine the mineral bone density in young adult patients with CF attended in the adult CF Unit, and correlate these findings with other clinical variables of interest in this patient population.

PATIENTS AND METHOD

We carried out a transversal study from 1999 to 2002 of 34 patients with CF (19 males and 15 females. Mean age 23 years). Upon enrollment in the study, patient gender and age were recorded along with Schwachman and Brasfield scores, pulmonary function test results (spirometry) and sputum analysis, phosphorus and calcium balance, vitamin D intake, and dual energy X-ray absorptiometry (DEXA) findings of the spinal column (L2-L4) and femur.

RESULTS

54.5% of all study patients were found to have an abnormal mineral bone density. Fifteen patients met criteria for osteopenia and 3 for osteoporosis. Age, treatment with inhaled corticosteroids, and pulmonary function test results correlated with bone density.

CONCLUSIONS

DEXA scans should be performed in young adults with CF at least once during the course of their illness on the basis of the high prevalence of mineral bone density abnormalities in this population.

Prevalence of pain in adults with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) may strongly condition the life of affected people. CF may be associated with relevant painful conditions caused by complications of the illness and also by therapy itself, which may represent an additional load of suffering. This study was aimed at evaluating the prevalence of pain symptoms in adult CF patients, if they are noticed and treated, and the influence of pain symptoms on patients' life.

METHOD

Using a questionnaire, we examined 239 adults with CF (17% of the whole Italian adult CF population).

RESULTS

We found a high prevalence of painful episodes among CF adult patients, as for both intensity and frequency. In a 2 months period 32.6% of patients experienced episodes of pain described as intense to severe, and 29.7% had more than 10 occurrences of pain in the same location. Headache, gastric pain and backache were the most frequently reported kind of pain. 59.8% of subjects perceived pain episodes as the cause of unfavorable effects on their life. Only 42.6% of those with pain asked a CF center physician for help and another 3.5% a general practitioner.

CONCLUSION

Painful symptoms can be the cause of a worsening of the quality of life for adults with CF; the relevance of pain in CF adult patients may often be underestimated; the assessment of pain should be routinely performed as a part of care in CF centers.

Treatment of monostotic fibrous dysplasia with pamidronate

INTRODUCTION

Fibrous dysplasia is a condition where fibrous tissue and bone with an altered structure replace normal bone. The craniofacial involvement is difficult to treat due to location, uncontrolled proliferation and compression of nerves. These result in facial asymmetry, pain, cranial nerve deficiencies, loss of vision or hearing, alterations in breathing, etc. The use of pamidronate, which inhibits the resorptive activity of osteoclasts may be an alternative to surgical intervention and may improve the results of treatment.

AIM OF STUDY

To evaluate the treatment of monostotic craniofacial fibrous dysplasia with pamidronate.

MATERIAL

A prospective pilot study was undertaken in 6 children with progressive fibrous dysplasia located in the mandible (3 pts), maxilla (2 pts) or cranial base (1 pt). Surgery consisted only of a biopsy and implantation of gentamycin sponge into the biopsy bed in 3 cases in which an infection was initially suspected. All patients received pamidronate infusions (1mg/kg i.v. for 3 days, every 4-6 months). The changes in bone density and extension of the disease were evaluated by serial orthopantomograms and CT scans. Follow up time was 9-24 months.

RESULTS

Pain relief was achieved in all cases, decrease in swelling in 3, and stabilization in 3 cases. Radiological investigation revealed any progression but reduction in size and calcification of osteolytic lesions. The local bone density increased and there was no further spread of the disease in any of the patients. Inflammatory symptoms resolved in all cases. The only side effect was an increase in body temperature up to 38-40 degrees C.

CONCLUSION

Pamidronate appears to be an effective and well-tolerated therapeutic option for patients with fibrous dysplasia. In the future, the combination of the metabolic blockage of the dysplasia by pamidronate and limited non-mutilating surgical interventions are possible.

Efficacy of Alendronate in Adults with Cystic Fibrosis with Low Bone Density

As adults with cystic fibrosis (CF) have enjoyed incremental increases in longevity over the last few decades, they have also been suffering from low bone density and its clinical manifestations, fractures and kyphosis. We conducted a placebo-controlled, randomized, double-blinded trial of alendronate (10 mg/day orally) (n = 24) compared with placebo (n = 24) for 1 year in 48 patients to improve bone mineral density at the spine as the primary endpoint. All patients received 800 IU of cholecalciferol and 1,000 mg of calcium carbonate. Both groups were similar in age, sex, CF mutations, bone density T scores, renal function, and body mass index at study onset. The alendronate-treated patients gained (mean +/- SD) 4.9 +/- 3.0% and 2.8 +/- 3.2% bone density after 1 year versus placebo, which lost (mean +/- SD) 1.8 +/- 4.0% and 0.7 +/- 4.7%, in spine and femur bone density, respectively (p < or = 0.001 for the spine; p = 0.003 for the femur). Urine N-telopeptide, a bone resorption marker, levels declined in the treatment group more than in the control group (p = 0.002), consistent with the known antiresorptive effects of bisphosphonates. Alendronate was more effective than placebo in improving spine and femur bone mineral density and is a promising agent for the long-term prevention and management of bone disease in patients with CF.

Adults with cystic fibrosis: meeting the challenge!

The number of adults with cystic fibrosis (CF) is increasing. They are striving for independence and a fulfilling life with focus on career, relationships, education and finances at a time when lung function is likely to be declining and complications of this multi-system disease are increasing. Maintaining the quality and improving the duration of life are continuing challenges for the -clinician and the patient. Increased hope and greater expectations have been provided by a number of recent clinical advances and active research into novel treatments, including gene therapy. There has been increased recognition of the necessity for early diagnosis, adequate monitoring and effective intervention for complications such as diabetes and osteoporosis. Research into multi-resistant bacteria and clonal strains of Pseudomonas aeruginosa is ongoing and attention has focused on infection control policies. Although more high-level evidence is required on many issues confronting people with CF, a considerable effort has been made over the last decade to provide a more evidence-based approach to therapy with a number of large controlled clinical trials. For the adult with CF, there are also more decisions to be made. There is focus on reproductive health, with most couples enjoying the real possibility of having children. For those with advanced disease, the option for lung transplantation is well established. Maintenance of quality care will require adequate planning, effective transition programmes from paediatric to adult care, specialized training for doctors, nurses and allied health professionals and the allocation of sufficient resources to accommodate the inevitable increase in patient numbers.

A randomized controlled trial of calcium with vitamin D, alone or in combination with intravenous pamidronate, for the treatment of low bone mineral density associated with Crohn's disease

BACKGROUND

Osteoporosis is a common complication of Crohn's disease.

AIM

To study the effect on the bone mineral density of a bisphosphonate (pamidronate) given intravenously, in combination with oral calcium and vitamin D supplements, compared with oral calcium and vitamin D supplements alone.

METHODS

Seventy-four patients with Crohn's disease and low bone mineral density at the lumbar spine and/or hip were randomized to receive either a daily dose of 500 mg of calcium with 400 IU of vitamin D alone or in combination with four three-monthly infusions of 30 mg of intravenous pamidronate over the course of 12 months. The main outcome measure was the change in bone mineral density at the lumbar spine and hip, measured by dual X-ray absorptiometry, at baseline and 12 months.

RESULTS

Both groups gained bone mineral density at the lumbar spine and hip after 12 months. There were significant (P < 0.05) changes in the pamidronate group, with gains of + 2.6%[95% confidence interval (CI), 1.4-3.0] at the spine and + 1.6% (95% CI, 0.6-2.5) at the hip, compared with gains of + 1.6% (95% CI, - 0.1-3.2) and + 0.9% (95% CI, - 0.4-2.1) at the spine and hip, respectively, in the group taking vitamin D and calcium supplements alone.

CONCLUSIONS

In patients with Crohn's disease and low bone mineral density, intravenous pamidronate significantly increases the bone mineral density at the lumbar spine and hip.

The role of bisphosphonates in diseases of childhood

Bisphosphonates are synthetic analogues of pyrophosphate that inhibit bone resorption by their action on osteoclasts. In recent years, bisphosphonates have been used in children for treatment of a growing number of disorders associated primarily with generalized or localized osteoporosis, metabolic bone diseases, heterotopic calcification in soft tissues, and for resistant hypercalcemia. In the present review we discuss the pharmacological aspects of bisphosphonates and related bone pathophysiology, review the pediatric literature on the role of bisphosphonates in childhood diseases and our experience with these drugs. The theoretical concerns of possible adverse effects of these drugs on the growing skeleton have not materialized in the limited pediatric clinical experience. Bisphosphonates provide the pediatrician with an opportunity to treat mineral and bone disorders of childhood which until recently did not have satisfactory therapy, at the same time, being aware of the theoretical concerns on microdamage accumulation in bone, bone quality and teratogenic potential of these drugs.

Short-term calcitriol administration improves calcium homeostasis in adults with cystic fibrosis

Osteoporosis is a well-defined health risk in cystic fibrosis (CF) patients due to many factors. Vitamin D insufficiency, despite routine cholecalciferol supplementation in CF patients, may contribute to a relative secondary hyperparathyroidism and possibly deficient bone mineralization. An alternate form of vitamin D, calcitriol, was studied to determine short-term effects on fractional calcium absorption and other calciotropic markers in 10 adult CF subjects and in 10 age-, sex- and body mass index (BMI)-matched controls. Serum fractional absorption of (45)Ca was determined after a calcium-containing meal prior to calcitriol intervention. Other measurements included serum parathyroid hormone (PTH), ionized calcium, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and urinary calcium:creatinine and N-telopeptide (NTx) concentrations. Both groups were then given calcitriol (0.5 micro g p.o. b.i.d. for 14 days) and restudied following the same protocol. Both groups increased their fractional absorption of (45)Ca after calcitriol ( p=0.015 CF subjects, p=0.001 controls), although calcitriol tended to be less effective in the CF group compared with the controls ( p=0.055). Post-prandial serum PTH concentrations were suppressed compared with baseline in both groups ( p=0.03 CF subjects, p=0.006 controls). Urinary NTx concentrations, a marker for bone resorption, decreased significantly in CF subjects after calcitriol (96.0+/-16.0 vs 63.9+/-12.7 nmol BCE/mmol Cr, p=0.01) and remained unchanged in the control group. The controls had an increase in serum 1,25(OH)(2)D concentrations (69.9+/-4.2 vs 90.7+/-9.6 pmol/l, p=0.02) while there was no significant change in the CF group. Oral calcitriol administration appears to improve markers of calcium balance in adults with CF by increasing fractional absorption of (45)Ca and lowering PTH concentrations, similar to its known effects in healthy subjects, while also suppressing urinary NTx, a marker of bone turnover.

Bilateral fractured neck of the femur in an adult patient with cystic fibrosis

A 34-year-old man with cystic fibrosis (CF) sustained a bilateral fractured neck of the femur during the course of six grand mal seizures. The fractures were successfully treated with bipolar hemi-arthroplasties. Several risk factors for osteoporosis were present. Bone pathology showed reduced femoral head bone density. Osteoporosis of the lumbar spine was confirmed by dual-energy X-ray absorptiometry. As the life expectancy of patients with CF continues to improve, osteoporosis and its sequelae will become more common. We should be aware of the increased risk of bilateral fractured neck of the femur following epileptic seizure in CF.

Histomorphometric analysis of bone biopsies from the iliac crest of adults with cystic fibrosis

This study reports the results of quantitative analysis of iliac bone histology in adults with cystic fibrosis (CF) and low bone mineral density (BMD). Twenty patients with CF had bone biopsies taken after double tetracycline labeling. Histomorphometric measurements were made by image analysis, and data were compared with those of healthy control subjects. Cancellous bone area was lower in the patients with CF (p = 0.003), and there was a trend towards a decrease in cancellous bone connectivity. Bone formation rate at tissue level was significantly lower in patients with CF (p = 0.0002). Wall width, representing the amount of bone formed within individual remodeling units, was decreased (p < 0.0001), as was mineralizing perimeter and mineral apposition rate. Analysis of resorption cavities revealed lower cavity area, reconstructed surface lengths, and cavity depths (p < 0.003) in patients with CF, whereas eroded surface area was higher (p = 0.0004). Our results demonstrate low cancellous bone volume in adult patients with CF with low BMD, the main cause of which appears to be low bone formation at tissue and cellular level. Osteomalacia was diagnosed in one patient. This condition should be excluded as a cause of low bone mineral density in patients with CF and vitamin D insufficiency corrected.

A review of nutritional problems and the cystic fibrosis lung transplant patient

Lung transplantation is an option for some cystic fibrosis (CF) patients. CF is associated with a variety of non-pulmonary problems, which should be managed before and after transplantation. This commentary discusses some of the nutritional issues affecting CF patients. Theses issues include: the need for nutritional supplements; gastrostomy tube placement; osteoporosis and diabetes.

A prospective study of change in bone mineral density over one year in adults with cystic fibrosis

BACKGROUND

Low bone mineral density (BMD) is prevalent in adults with cystic fibrosis. To identify appropriate therapeutic strategies and the optimal time for intervention, it is necessary to document the natural history of cystic fibrosis related low BMD.

METHODS

114 adults with cystic fibrosis underwent bone densitometry a median (25-75% interquartile range) of 12 (12-13) months after initial assessment of bone density. BMD was measured in the lumbar spine, femoral neck, total hip, and distal forearm on recruitment to the trial and at follow up.

RESULTS

In patients <or=24 years of age (n=55, mean (SD) age 19.5 (2.6) years) in whom an annual increase in BMD would normally be expected, BMD increased by a mean (95% CI) 2.9% (1.6 to 4.2) per year in the distal forearm (p<0.001), but decreased by 2.5% (95% CI -3.8 to -1.2) per year in the femoral neck (p<0.001) and by 2.2% (95% CI -3.3 to -1.0) per year in the total hip (p<0.001). In patients >or=25 years of age (n=59, mean (SD) age 30.3 (5.4) years) in whom no annual change in BMD would normally be expected, BMD decreased by 1.9% (95% CI -2.9 to -0.8) per year in the femoral neck (p<0.001), by 1.5% (95% CI -2.4 to -0.6) per year in the total hip (p=0.001), and by 0.8% (95% CI -1.5 to -0.1) per year in the distal forearm (p=0.026). There was no significant annual change in lumbar spine BMD in either patient cohort.

CONCLUSIONS

Reduced rates of bone accretion and accelerated rates of bone loss explain the high prevalence of low BMD in adults with cystic fibrosis.

Bisphosphonates in bone diseases other than osteoporosis

The range of bone diseases in which bisphosphonates are used has extended far beyond osteoporosis during the last few years. Bisphosphonate therapy is now so well validated as to be the reference standard in Paget's disease and in the prevention of bone complications related to malignant osteolysis. Promising preliminary findings warrant the use of bisphosphonates in conditions that are either rare (fibrous dysplasia) or severe (pediatric osteogenesis imperfecta). The third category of indications encompasses many conditions in which the limited available data do not warrant widespread use: examples include reflex sympathetic dystrophy syndrome, acute back pain after a vertebral crush fracture, and chronic inflammatory joint disease not treated by glucocorticoids.

Impact of lung inflammation on bone metabolism in adolescents with cystic fibrosis

Deficits in bone mineral density resulting in premature osteopenia and osteoporosis have been documented in cystic fibrosis patients for over 20 years. A high incidence of fractures and kyphosis in the continually increasing adult patient population and in post-lung transplant patients has highlighted the problems associated with poor bone health.The aetiology of osteoporosis in CF is multifactorial but centres on an uncoupling in the normal balance between bone formation and resorption. Delayed puberty, malabsorption and reduced weight-bearing exercise can result in inadequate bone mineral accretion in childhood and adolescence. Corticosteroid use and pro-inflammatory cytokines associated with infective respiratory exacerbations can accelerate bone loss. Dual energy X-ray absorptiometry is the most commonly available technique to measure bone mineral density. All patients should be scanned at least every 2 years from adolescence. The treatment of established disease with bisphosphonates shows encouraging early results.

Bisphosphonates for osteoporosis in people with cystic fibrosis

BACKGROUND

Osteoporosis is a disorder of bone mineralization that can lead to reduced bone mineral density and an increased risk for fractures. It is found in about one third of adults with cystic fibrosis. Bisphosphonates have been shown to increase bone mineral density and decrease the risk of new fractures in post-menopausal women and in patients receiving long-term oral corticosteroids.

OBJECTIVES

To assess the effects of bisphosphonates on the frequency of fractures, bone mineral density, quality of life, adverse events, study withdrawals, and survival in people with cystic fibrosis.

SEARCH STRATEGY

Relevant trials were identified in the Cochrane Cystic Fibrosis and Genetic Disorders Review Group specialised register of controlled trials by the centre co-ordinator. This register comprises references identified from comprehensive electronic database searches, handsearching of relevant journals and of conference proceedings. Additional sources such as abstract books for osteoporosis conferences were hand-searched by the authors. The most recent search(es) were conducted in February 2001.

SELECTION CRITERIA

Randomised controlled trials of at least six months duration that studied the use of bisphosphonates in adults with cystic fibrosis were considered for inclusion. Outcomes included one of the following: fractures, bone mineral density, quality of life, adverse events, study withdrawals, or survival.

DATA COLLECTION AND ANALYSIS

Information on study design, participants, interventions, and outcomes was abstracted from included studies. Two independent reviewers abstracted the information. Authors were contacted to obtain missing data.

MAIN RESULTS

Two trials were identified in the trials search. Both trials with a total of 65 participants were included in this review. One study examined patients without lung transplants while the other study included only patients who had received a lung transplant. The intervention in both trials was pamidronate administered intravenously every three months. In patients who had not received a lung transplant, bone mineral density at axial sites was increased after six months of treatment in the treatment group compared to the control group (lumbar spine WMD [for % change BMD] = 5.8 [95% CI 4.63 to 6.97], hip WMD = 3.00 [95% CI 1.99 to 4.01]). There was a small decrease in forearm bone mineral density in patients treated with pamidronate versus controls (distal forearm WMD = -1.70 [95% CI -2.46 to -0.94]). Bone pain was the most common adverse event occurring in 11/15 participants not using corticosteroids (RR = 24.40, 95% CI 1.57 to 381.48). There was no difference in survival (RR = 1.00, 95% CI 0.83 to 1.20), although this may be due to short follow-up and small sample size. In patients who had received a lung transplant, the number of new fractures did not change with the use of pamidronate (non-vertebral RR = 3.38 [95% CI 0.39 to 29.29], vertebral RR = 0.56 [95% CI 0.17 to 1.89]). Bone mineral density at axial sites was increased after two years of treatment in the treatment group compared to the control group (lumbar spine WMD [for % change in BMD] = 6.20 [95% CI 4.28 to 8.12], femur WMD = 7.90 [95% CI 5.78 to 10.03]).

REVIEWER'S CONCLUSIONS

Intravenous pamidronate increases bone mineral density at axial sites in people with cystic fibrosis, although it can cause severe bone pain in patients not receiving corticosteroids. Additional studies in larger populations are needed to determine the effect on fracture rate and survival.