Bone mineral density in normal and asthmatic children

Evaluation of vitamin D deficiency and low bone mass in children with asthma in fars province: A case-control study

Background and Aims

Asthma is a chronic inflammatory pulmonary disease which affects 10%-20% of children and adolescents. Inhaled corticosteroids (ICS) is one of its most effective therapies. The effect of systemic corticosteroids on decreasing bone mineral density (BMD) was investigated and proved in children; however, the influence of ICSs on bone density has still remained unclear. This study evaluates the bone mineral density of children and adolescents with asthma in southern Iran and the associated factors, for example, amount of used inhaled steroid.

Method

This case-control study enrolled 41 children and adolescents (aged 8-18 years) with asthma and their age and gender-matched controls in 2019-2020. Serum Calcium, phosphate, vitamin D, and bone mineral density were measured. Their physical activity, sun exposure, and fracture history were evaluated subjectively.

Results

Lumbar BMD and BMD Z-score in patients showed no significant difference with controls (p = 0.23, p = 0.73). Also, it showed that there was no significant difference in biochemical studies, growth, and bone densitometry parameters between patients who used ICSs for less than 3 months/year corticosteroid therapy compared to those with equal or more than 3 months/year usage. Prevalence of vitamin D deficiency was 28% and 8% in the controls and patients, respectively (p = 0.005).

Conclusion

The present study showed that 9.46% of children and adolescents with asthma had low bone mass for chronological age, and it is not significantly higher than normal population. Dosage of inhaled steroid did not associate with osteoporosis in these patients. Prevalence of vitamin D deficiency in patients was lower than normal population, probably due to receiving vitamin D in their routine follow-ups.

Are asthmatic patients prone to bone loss?

BACKGROUND

Recent studies suggest an association between allergic diseases, including asthma, and lower vitamin D level, a well-known risk factor of osteoporosis. However, it is not yet clearly known whether patients with asthma are prone to bone loss.

OBJECTIVE

To evaluate whether the occurrence of airway hyperresponsiveness (AHR) or asthma is related to significant changes in bone mineral density (BMD).

METHODS

We retrospectively enrolled 7,034 patients who had undergone a health checkup program, including BMD tests and methacholine bronchial challenge tests, at the Seoul National University Hospital, Healthcare System Gangnam Center, from November 1, 2004 to April 30, 2011. Asthma was ascertained by self-reported medical diagnosis by a physician. Patients with a history of systemic corticosteroid medication use were excluded from the study.

RESULTS

Among a total of 7,034 patients, 216 (3.1%) had a positive AHR test result, and 217 (3.1%) had a history of asthma. Lumbar spine and femur BMD of patients with AHR were significantly lower than those without AHR (-0.53 ± 1.50 vs -0.03 ± 1.49, -0.47 ± 0.97 vs -0.22 ± 0.99, respectively; P < .001 for both). After being adjusted for age, sex, body mass index, smoking status, postmenopausal state, and previous history of hormone replacement therapy, the proportion of patients with osteopenia or osteoporosis was much higher in the AHR-positive group than in the AHR-negative group (odds ratio, 1.715; 95% confidence interval, 1.252-2.349) and in the ever-asthma group than in the never-asthma group (odds ratio, 1.526; 95% confidence interval, 1.120-2.079).

CONCLUSION

In the current study, AHR and asthma were related to clinically meaningful BMD decrease, although the causal relationship is unclear.

Therapeutic management of allergic diseases

Allergic diseases are characterized by the activation of inflammatory cells and by a massive release of mediators. The aim of this chapter was to describe succinctly the modes of action, indications, and side effects of the major antiallergic and antiasthmatic drugs. When considering the ideal pharmacokinetic characteristics of a drug, a poorly metabolized drug may confer a lower variability in plasma concentrations and metabolism-based drug interactions, although poorly metabolized drugs may be prone to transporter-based disposition and interactions. The ideal pharmacological properties of a drug include high binding affinity, high selectivity, and appropriate association and dissociation rates. Finally, from a patient perspective, the frequency and route of administration are important considerations for ease of use.

Asthma

Asthma has been recognized as a disease since the earliest times. In the Corpus Hippocraticum, Hippocrates used the term “ασθμα” to indicate any form of breathing difficulty manifesting itself by panting. Aretaeus of Cappadocia, a well-known Greek physician (second century A.D.), is credited with providing the first detailed description of an asthma attack [13], and to Celsus it was a disease with wheezing and noisy, violent breathing. In the history of Rome, we find many members of the Julio-Claudian family affected with probable atopic respiratory disorders: Caesar Augustus suffered from bronchoconstriction, seasonal rhinitis as well as a highly pruritic skin disease. Claudius suffered from rhinoconjunctivitis and Britannicus was allergic to horse dander [529]. Maimonides (1136–1204) warned that to neglect treatment of asthma could prove fatal, whereas until the 19th century, European scholars defined it as “nervous asthma,” a term that was given to mean a defect of conductivity of the ninth pair of cranial nerves.

[Inhaled corticosteroid therapy and bone metabolism in asthmatic children]

OBJECTIVE

To explore the association between inhaled corticosteroids (ICS) therapy and bone metabolism.

PATIENTS AND METHODS

The sample was composed of 151 children, aged between 1 and 17 years. There were 71 asthmatics treated with ICS for at least 6 months (group 1), 44 asthmatics treated occasionally with ICS during exacerbations (group 2), and 36 healthy children (group 3). Bone mineral density (BMD) and markers of bone formation and resorption were measured. These measures, as well as other related factors, were compared among groups. Regression models for osteopenia and BMD were used with the group as the independent variable adjusted by factors with differences between groups. A two-tailed level of p < 0.05 was used in all tests.

RESULTS

No differences in BMD were found between groups 1 and 2 but significant differences were found between groups 1 and 3 (p = 0.003). No differences were found in markers of bone formation and resorption among the groups. No association was found between BMD and the type, daily dose or accumulated dose of ICS. Group 1 showed an osteopenia odds ratio relative to group 3 of 2.94 (95 % CI: 1.49-5.78) and an average reduction of BMD of 0.50 (95 % CI: 0.32-0.68) was found from group 3 to 2 and from group 2 to 1. In group 1, markers of bone resorption significantly increased in asthmatics with osteopenia compared with those without osteopenia.

CONCLUSIONS

ICS treatment in asthmatic children seems to affect BMD. Markers of bone formation and resorption are unaffected. Osteopenia in these children could also be related to other factors that increase bone resorption.

Fracture risk in patients with chronic lung diseases treated with bronchodilator drugs and inhaled and oral corticosteroids

BACKGROUND

Chronic lung diseases and drugs used to treat patients with chronic lung diseases may be associated with an increased fracture risk.

METHODS

The design was a case-control study of all patients with a fracture (n=124,655) in the year 2000 in Denmark as case subjects. For each case subject, three age- and gender-matched control subjects were randomly drawn from the general population (n=373,962).

RESULTS

Chronic lung diseases such as COPD (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.13 to 1.25), emphysema (OR, 1.31; 95% CI, 1.16 to 1.48), and other chronic lung diseases (OR, 1.20; 95% CI, 1.00 to 1.44) were associated with a higher relative risk of any fracture than asthma (OR, 1.06; 95% CI, 1.01 to 1.12). Oral corticosteroids were associated with a dose-dependent increased risk of fractures. Inhaled short-acting beta-agonists were associated with an increase in fracture risk that was not dose dependent and was seen already at low doses. Oral beta-agonists were associated with an increase in fracture risk at low doses but not at higher doses. Other bronchodilators (inhaled long-acting beta-agonists, inhaled beta-agonists plus inhaled corticosteroids, inhaled beta-agonists plus antimuscarinic substances, inhaled antimuscarinic substances, inhaled cromoglycate and cromoglycate-like substances, oral theophylline, and oral leukotriene receptor antagonists), and inhaled corticosteroids were not associated with fracture risk.

CONCLUSIONS

The increase in fracture risk seen with inhaled short-acting beta-agonists may be linked to the severity of the underlying lung disease rather than with the beta-agonists, per se, as other types of beta-agonists were not associated with fractures.

Inhaled corticosteroids, bone mineral density and fracture in older people

The efficacy of inhaled corticosteroids in the treatment of asthma has been firmly established in a variety of settings. The majority of asthma management plans now recommend the use of inhaled corticosteroids at an early stage. This means that most patients with asthma will be prescribed an inhaled corticosteroid at some point in time and many patients with asthma will use these drugs for several years. Inhaled corticosteroids are also used in the treatment of other conditions, particularly chronic obstructive pulmonary disease (COPD). Since inhaled corticosteroids are absorbed into the systemic circulation, they can have systemic adverse effects, such as suppression of the hypothalamic-pituitary-adrenal axis and increasing the risk of bruising. However, perhaps the greatest concern for patients is whether the regular use of inhaled corticosteroids has an adverse impact on the bone mineral density and increases the risk of fracture. There is now accumulating evidence from epidemiological studies that the use of inhaled corticosteroids is inversely related to bone mineral density in a dose-dependent fashion. However, data from two clinical trials of moderately high doses of inhaled corticosteroids in patients with COPD have produced conflicting results and while the larger study of triamcinolone found a significant impact of this drug on bone mineral density, a smaller study of budesonide found no effect. Epidemiological research into the relationship between inhaled corticosteroids and fracture is at an early stage. To date, only three studies in this area have been reported, all of which have used different approaches to try to minimise the impact of bias and confounding. There is a lack of consistency between the final estimates of the impact of inhaled corticosteroids on fracture risk. However, taken together these data suggest that the short to medium term use of inhaled corticosteroids is associated with a small adverse effect on bone. Doctors and patients need to be aware of this risk and balance it against the known beneficial effects of inhaled corticosteroids.

Are inhaled corticosteroids associated with an increased risk of fracture in children?

Inhaled corticosteroids are widely used in the long-term management of asthma in children. Data on the relationship between inhaled corticosteroid therapy and osteoporotic fracture are inconsistent. We address this issue in a large population-based cohort of children aged 4-17 years in the UK (the General Practice Research Database). The incidence rates of fracture among children aged 4-17 years taking inhaled corticosteroids (n=97,387), taking bronchodilators only (n=70 984) and a reference group (n=345,758) were estimated. Each child with a non-vertebral fracture (n=23,984) was subsequently matched by age, sex, practice, and calendar time to one child without a fracture. Fracture incidence was increased in children using inhaled corticosteroids, as well as in those receiving bronchodilators alone. With an average daily beclomethasone dose of 200 microg or less, the crude fracture risk relative to nonusers was 1.10 [95% confidence interval (CI), 0.96-1.26]; with dosage of 201-400 microg, it was 1.23 (95% CI, 1.08-1.39); and with dosages over 400 microg, it was 1.36 (95% CI, 1.11-1.67). This excess risk disappeared after adjustment for indicators of asthma severity. The increased risk of fracture associated with use of inhaled corticosteroids is likely to be the result of the underlying illness, rather than being directly attributable to inhaled corticosteroid therapy.

Systematic review of the evidence regarding potential complications of inhaled corticosteroid use in asthma: collaboration of American College of Chest Physicians, American Academy of Allergy, Asthma, and Immunology, and American College of Allergy, Asthma, and Immunology

INTRODUCTION

The available clinical guidelines have been successful in improving awareness of the inflammatory nature of asthma and have promoted the use of inhaled corticosteroids (ICSs) to achieve long-term control of symptoms. Because of lingering concerns over the possible adverse consequences of ICS use, an expert panel was convened with a mandate to identify the critical questions that impact decisions regarding the use of ICSs and to evaluate the available evidence with respect to risk.

METHODS

A university librarian retrieved citations and abstracts from the MEDLINE and EMBASE databases using a list of National Library of Medicine search terms and key words. Reviewers were asked to systematically abstract relevant information from each of their assigned articles and to list their own clinical or scientific conclusions based on the study results. A predefined grading algorithm was used to calculate a summary quality rating score for the relevant evidence.

RESULTS

The results are presented as a series of key questions followed by a summary of the relevant evidence. An evidence grade is assigned, followed by a summary statement reflecting the panel's consensus opinion following review.

CONCLUSIONS

The preponderance of evidence supports a conclusion that the proven clinical effectiveness of ICS treatment decidedly outweighs the proven risks.

Long-term outcomes in paediatric asthma

Over the years the aims of asthma management have changed markedly from effective prednisolone treatment of symptoms and exacerbations towards more use of continuous prophylactic treatment. With our new understanding of the disease and its management definition of the aims of treatment and assessment of optimal asthma control have become much more complex. Even in times of evidence-based medicine our asthma management is based upon findings of effects on various outcomes in somewhat short-term (<1 year) controlled studies. However, assumptions about long-term effects upon the basis of findings in such studies should be made with great caution. Good examples of this are studies which assess the risk of systemic effects and clinical adverse effects of inhaled corticosteroids. From such studies it has become clear that systemic effects detected in short-term trials may have no predictive value of long-term adverse effects. Thus steroid-induced changes in lower leg growth rates assessed by knemometry do not predict long-term statural growth. Moreover, steroid-induced changes in statural growth over 1 year are not predictive of effects upon attained adult height. In contrast, reduced growth caused by uncontrolled asthma disease also seems to affect attained adult height adversely. These findings suggest that long-term outcomes should play a larger role when future asthma management strategies are decided. Some important long-term outcomes of asthma management in children include cure or remission of the disease, prevention of complications of the disease (airway remodelling, adverse effects upon growth/adult height, peak bone mineral density, physical impairment and psychosocial development) or its pharmacological management (adverse effects upon adult height, peak bone mineral density). More controlled long-term studies (several years) are needed to provide a better understanding of how these outcomes are best achieved.

Growth and bone density in children with mild-moderate asthma: a cross-sectional study in children entering the Childhood Asthma Management Program (CAMP)

OBJECTIVES

We sought to determine whether mild-moderate persistent asthma sufficient to produce a decrease in baseline lung function is associated with an adverse effect on growth and bone mineral density (BMD) in children.

METHODS

This was a cross-sectional study of 1041 children, 5 to 12 years old (32% ethnic/racial minorities and 40% female), enrolled into the Childhood Asthma Management Program (CAMP). Measures of asthma severity included: Spirometry; bronchial hyperresponsiveness; duration of asthma symptoms; and symptom-based assessment of severity. Multiple regression analyses were used to relate the asthma severity on the primary outcome variables: Height by stadiometry and BMD by dual energy radiographic absorptiometry.

RESULTS

The mean +/- SD height percentile was 56.0 +/- 28.5 percentile for the population. The only significant relationship between asthma severity and height percentile was with methacholine bronchoprovocation in girls (beta 2.98, P =.019, covariate multiple regression). The mean +/- SD BMD was 0.65 +/- 0.10 g/cm(2) for the population. The past use of corticosteroids did not adversely affect either growth or BMD.

CONCLUSIONS

We found that mild-moderate asthma of as long as 4 to 7 years duration in children does not produce an adverse effect on linear growth or BMD.

Effect of inhaled steroids on bone mineral density: a meta-analysis

Inhaled corticosteroids are currently considered first-line agents for the treatment of asthma. Medium- to long-term administration of inhaled steroids may be associated with bone loss. Various studies have evaluated their effect on bone mineral density (BMD); some have shown loss of BMD with steroid treatment, but others have failed to do so. The present meta-analysis was undertaken to determine the possible effect of inhaled steroids on bone density. Literature was collected using computerized (MEDLINE) and manual searches using index medicus and checking cross-references of the published articles. The studies identified were screened for inclusion/exclusion criteria. Grouped means (XT/XC) and pooled standard deviations (SDT/SDC) for the treatment group (XT[95% CI] = 1.144 [1.019-1.269]; SDT = 0.163, g/cm2) and control group (XC [95% CI] = 1.193 [1.073-1.313]; SDC = 0.157, g/cm2) were worked out respectively for the selected studies. Finally, a comparison between grouped means of steroid-treated and control groups was done by two-sample t-test at the 5% level of significance. The results of the meta-analysis showed that although the mean BMD of the steroid-treated group was reduced by 4.1% as compared to the control group, this failed to achieve statistical significance (p = 0.8; 95% CI for the mean difference between two groups = 0.028-0.070 g/cm2). It is concluded that inhaled steroids for the treatment of asthma can be considered safe with respect to their effect on bone loss.

Safety profile of frequent short courses of oral glucocorticoids in acute pediatric asthma: impact on bone metabolism, bone density, and adrenal function

OBJECTIVE

Our study was designed to establish in children with asthma the safety profile of repeated short courses of oral glucocorticoids on bone mineralization and metabolism and adrenal function.

METHODS

This cross-sectional study compared the bone density, bone metabolism, and adrenal function of children who were and were not exposed to bursts of oral glucocorticoids. Children were considered exposed when, in the preceding year, they received >or=2 courses of oral glucocorticoids and were prescribed the same therapy for the index exacerbation. Children were considered unexposed when they had no exposure to oral glucocorticoids and were not prescribed any for the index exacerbation. Indices of bone metabolism were measured during the subsequent month. Cortisol responses to adrenocorticotrophic hormone stimulation and bone density were assessed 30 days after the index exacerbation.

RESULTS

Eighty-three children (48 exposed, 35 unexposed) aged 2 to 17 years were enrolled. The median exposure level was 4 courses (range: 3-11) in the preceding year. Among exposed children, a transient decrease in serum osteocalcin was observed at the end of the 5-day course with a return to baseline by 30 days; no change was observed in urine pyridinoline cross-links. Mean bone density z score was similar in the exposed (-0.61 +/- 1.0 [standard deviation]) and unexposed (-0.67 +/- 0.9) groups. No cases of abnormal response to adrenocorticotrophic hormone suggestive of adrenal insufficiency were documented in the exposed (95% confidence interval: 0%-7%) or unexposed (0%-10%) groups.

CONCLUSIONS

Repeated short courses of oral glucocorticoids in the treatment of asthma seem to be reasonably safe; this practice was not associated with any lasting perturbation in bone metabolism, bone mineralization, or adrenal function.

Inhaled corticosteroids and hip fracture: a population-based case-control study

There is accumulating evidence that the use of inhaled corticosteroids is associated with a dose-related reduction in bone mineral density. Whether this translates to an increase in fracture is unclear. We have used the General Practice Research Database to perform a case-control analysis, including 16,341 cases of hip fracture (mean age of 79 years, 79% female, median period prescribing data 2.7 years) and 29,889 control subjects, individually matched by age, sex, and general practice. Data for all prescriptions for corticosteroids and for potential confounders, including other drug use and comorbid illnesses, were extracted, and the impact of inhaled corticosteroid exposure was analyzed using conditional logistic regression. The risk of hip fracture was associated with exposure to inhaled corticosteroids with an odds ratio of 1.26 (95% confidence interval, 1.17 to 1.36). This odds ratio was reduced after adjusting the model for annual courses of oral corticosteroids, the only confounder of note (OR 1.19; 95% CI, 1.10 to 1.28). There was a dose-response relationship between inhaled corticosteroid use and hip fracture even after adjusting for the annual number of courses of oral corticosteroids (p trend = 0.007). In older subjects, the recent use of inhaled corticosteroids is associated with a dose-related increase in hip fracture.

Effects of asthma and asthma therapies on bone mineral density

With improvements in techniques for measuring bone mass, interest and concern have increased about the effects of asthma therapies, particularly corticosteroids, on bone mineral density. Whether asthma itself causes bone loss remains unclear. Studies evaluating the effect of asthma therapies on bone mineral density are often difficult to interpret because of methodologic problems. These studies show that oral corticosteroids are associated with a reduction in bone mineral density and an increased risk of fracture. Studies evaluating the effects of inhaled corticosteroids on bone mineral density provide conflicting data, but there is increasing evidence that inhaled corticosteroids may have an adverse effect on bone. However, the benefits of inhaled corticosteroids in the treatment of asthma remain far greater than the risks. The data for the effects of other asthma therapies on bone mineral density are limited.

Osteoporosis in childhood: bone density of children in health and disease

Bone mineral density in later life largely depends on the peak bone mass achieved in adolescence or young adulthood. A reduced bone density is associated with increased fracture risk in adults as well as in children. Pediatricians should therefore play an important role in the early recognition and treatment of childhood osteoporosis. Juvenile idiopathic osteoporosis and osteogenesis imperfecta are examples of primary osteoporosis in childhood. However, osteoporosis is more frequently a complication of a chronic disease or its treatment. This paper provides an overview of bone and bone metabolism in healthy children and the use of diagnostic tools, such as biochemical markers of bone turnover and several bone densitometry techniques. Furthermore, a number of diseases associated with osteoporosis in childhood and possible treatment strategies are discussed.

Asthma, inhaled corticosteroid use, and bone mass in prepubertal children

The aim of this cross-sectional study was to describe the role of asthma, asthma severity, and medication usage in bone mineralization of prepubertal children. Asthma severity, medication usage, and physical activity were assessed by questionnaire and objective measures in 330 children. Bone densitometry and body composition were measured by dual-energy x-ray absorptiometry. Asthma ever was reported by 110 subjects (33%). A diagnosis of asthma was not associated with any deficit in bone mass, whereas usage of inhaled corticosteroids (ICS) in the last year (but not past use) was associated with deficits in bone in the total body (only after adjustment for confounders), particularly for doses of > or =400 microg/day. These observations support current recommendations with regard to ICS usage in children, but require confirmation in longitudinal studies.

Bone mineral density in prepubertal asthmatics receiving corticosteroid treatment

OBJECTIVE

To examine whether bone mass is reduced in prepubertal, asthmatics receiving high doses of inhaled corticosteroids.

METHODOLOGY

A cross-sectional comparison of lumbar spine-bone mineral density (LS-BMD) was undertaken in 76 subjects after stratifying them according to dosage and administration route of corticosteroid.

RESULTS

Weight was the only independent predictor of LS-BMD (r(2) = 0.38). Children receiving greater than 800 microg/day of inhaled corticosteroid plus intermittent oral corticosteroid had a significantly lower weight-adjusted LS-BMD than children treated with 400-800 microg/day of inhaled corticosteroid (mean difference: 0.06 g/cm(2), 95% confidence interval (CI): - 0.02 to - 0.10). A significant difference in weight-adjusted LS-BMD persisted when all children receiving greater than 800 microg/day of inhaled corticosteroid, irrespective of additional oral corticosteroid treatment, were compared with children receiving 400-800 microg/day of inhaled corticosteroid (mean difference: - 0.05 g/cm(2), 95%CI interval: -0.02 to - 0.09). Bone mass was similar in children not receiving any inhaled corticosteroid and those treated with 400-800 microg/day of inhaled corticosteroid.

CONCLUSIONS

A reduced bone mass in prepubertal asthmatic children receiving high doses of inhaled corticosteroids may predetermine a compromised peak bone mass and increase osteoporotic fracture risk in adulthood.

Osteoporosis in the corticosteroid-treated patient with asthma

Osteoporosis affects 40% of white women older than 45 years of age and 15% of white men older than 50 years of age, resulting in approximately 1.5 million annual fractures in the United States. Systemic corticosteroid therapy increases the probability of osteoporosis, even with alternate-day dosing and with dosages sufficiently low so as not to affect the hypothalamic-pituitary-adrenal axis. Inhaled corticosteroid therapy may affect bone density if high-dose therapy is given to select individuals. The potential of increasing osteoporosis with inhaled corticosteroid asthma therapy is a concern because of the availability of more potent inhaled corticosteroid agents and recommendations that inhaled corticosteroid therapy be initiated earlier in the course of asthma. This article provides suggestions, on the basis of the medical literature and consensus of the authors when specific information was not available, for assessing and treating osteoporosis in subjects with asthma. Suggested risk categories are "low risk" (inhaled corticosteroid dosage of < or =800 microg of heclomethasone dipropionate [BDP]/day in adults or < or =400 microg BDP or equivalent in children), "moderate risk" (inhaled BDP >800 microg/day in adults or >400 microg/day in children), and "high risk" (systemic corticosteroid therapy 4 times a year or daily or alternate-day systemic corticosteroid therapy). Dosage of nasal corticosteroid probably should be added to the orally inhaled corticosteroid for total burden of inhaled corticosteroid. Potential treatment strategies based on risk factors and bone density if indicated are offered to assist physicians treating patients with asthma.

Evaluation of bone mineral density in children receiving antiepileptic drugs

The effects of the valproic acid and carbamazepine monotherapies on bone mineral density were evaluated. Bone mineral density was measured in 53 children with primary epilepsy taking either valproic acid (n = 25) or carbamazepine (n = 28) for longer than 1 year and in a healthy control group (n = 26) by the dual-energy x-ray absorptiometry method at L2-L4 levels of lumbar vertebrae. The mean serum levels of valproic acid and carbamazepine were 66 +/- 2.2 microg/mL and 7.0 +/- 9.3 microg/mL, respectively, and the mean duration of treatment for each drug was 2.4 +/- 0.2 years and 2.6 +/- 0.5 years, respectively. Calcium intakes in diet were similar in both the control and study groups. The serum levels of calcium and phosphorus in all groups were normal. Bone mineral density values of both valproic acid and carbamazepine groups were not statistically different from that of the control group (P > 0.05).

Longitudinal evaluation of bone mass in asthmatic children treated with inhaled beclomethasone dipropionate or cromolyn sodium

Inhaled corticosteroids are recommended as first-line therapy in patients with moderate to severe asthma. The use of these agents in the milder form of asthma is controversial because of their potential adverse effects, especially in growing children. We investigated 49 asthmatic children (38 treated with beclomethasone dipropionate (BDP) at a daily dose of 276+/-125 microg/day and 11 treated with cromolyn sodium (CS) at a daily dose of 30+/-10 mg/day) for 7.4 months, with bone-mass measurements at baseline and after the treatment period. Evaluation of changes in cortical and trabecular bone mass (bone mineral density [BMD]; m/cm2) was performed by absorptiometry at the proximal forearm and at the lumbar spine, respectively. Furthermore, to correct for bone size changes due to growth, we calculated volumetric BMD (VOL-BMD; mg/cm3). At the end of the treatment period, the children who had received regular inhaled BDP had grown as well as children treated with CS, from 120+/-1.4 to 123+/-1.3 cm and from 118+/-3.2 to 120.3+/-2.8 cm, respectively. No children showed deviation from their percentile level of growth. Trabecular and cortical BMD increased after 7 months of follow-up in both groups to the same extent. When BMD was adjusted for body size (VOL-BMD; mg/cm3), bone mass was found not to have changed after BDP or CS treatment course within and between the two groups.

Bone mineral density in children with asthma receiving long-term treatment with inhaled budesonide

The aim of our study was to assess the effects of long-term treatment with inhaled budesonide (BUD) on total body bone mineral density (BMD), total body bone mineral capacity (BMC), total bone calcium (TBC), and body composition in children with asthma. Dual energy X-ray absorptiometry (DEXA scan) was performed in 157 asthmatic children treated with inhaled BUD at a mean daily dose of 504 microg (range, 189 to 1,322 microg) for 3 to 6 yr (mean, 4.5 yr). Measurements were compared with those of 111 age-matched children also suffering from asthma but who had never been treated with exogenous corticosteroids for more than 14 d (control group). There were no statistically significant differences between the two groups in BMD (BUD = 0.915 g/cm2, controls = 0.917 g/cm2), BMC (BUD = 1,378 g, controls = 1,367 g), TBC (BUD = 524 g, controls = 519 g), or body composition (lean body weight = 27,600 g [BUD] and 26,923 g [control], % body fat = 20.1% [BUD] and 20.3% [control]). Furthermore, there was no correlation between any of these parameters and duration of treatment, accumulated or current dose of budesonide. Three to six years of treatment with inhaled budesonide at an average daily dose of 504 microg has no adverse effect on total BMD, total BMC, TBC, or body composition in children with chronic asthma.

Bone mineral density and bone metabolism of prepubertal children with asthma after long-term treatment with inhaled corticosteroids

Little is known about the effect of long-term treatment with inhaled corticosteroids (ICS) on bone mineral density (BMD) in asthmatic children. In the present cross-sectional study BMD, bone metabolism, height, body composition, and bone age were evaluated in 40 prepubertal children (21 boys) with asthma, treated with a moderate to high dose of ICS over a period of 3 to 8 years. Body composition and BMD of the lumbar spine and total body were measured by Dual Energy X-ray Absorptiometry. BMD results were compared with 148 prepubertal healthy children of the same population. Blood samples were taken for the determination of biochemical bone parameters. The asthmatic children had decreased height, lean tissue mass and fat mass, and a delay of bone maturation, indicating growth retardation. ICS-treated asthma was negatively correlated with total body BMD in a multiple regression model with adjustment for age, gender, height and weight (P = 0.01). Duration of ICS therapy correlated negatively with total body BMD when it was added to the model (P = 0.01). Lumbar spine BMD was not affected by ICS in children with ICS-treated asthma. If age of the asthmatic children was replaced by their bone age in the model, no significant correlation was found between ICS-treated asthma and total body or lumbar spine BMD. The biochemical parameters of bone metabolism were within normal limits. In conclusion, children with asthma who have used ICS daily for 3 to 8 years had lower total body BMD than healthy controls. Long-term longitudinal studies are needed to investigate whether these children attain a normal peak bone mass.

Cross sectional investigation of the effects of inhaled corticosteroids on bone density and bone metabolism in patients with asthma

BACKGROUND

Bone mineral density has been reduced in patients with asthma taking inhaled corticosteroids in some cross sectional studies and this could be important if treatment is continued for several decades. The possibility of confounding by age, menopausal status, physical activity and, especially, past oral steroid use has not been excluded in most studies. The present study was designed to assess the magnitude of any reduction in bone mineral density in relation to inhaled steroid use after adjusting for these factors.

METHODS

Bone mineral density (BMD), vertebral fractures, and markers of bone metabolism (serum osteocalcin, procollagen peptide I, bone-specific alkaline phosphatase, and urinary deoxypyridinoline cross links) were measured in 81 patients with asthma age 20-40 years; 34 patients (19 men) who had never had inhaled or systemic steroids and 47 (19 men) who had taken inhaled steroids for at least five years with limited exposure to systemic steroids in the past. Data relating to past medication use, physical activity, smoking, and other confounding factors were collected by questionnaire. The relation between inhaled steroid dose and duration and BMD was assessed by linear regression analysis, accounting for potential confounders including weight, exercise, and oral steroid use.

RESULTS

The 47 patients taking an inhaled steroid had a mean current dose of 620 micrograms/day (range 100-3000 micrograms), a mean duration of use of 7.8 years, and had had a mean of 0.85 courses of prednisolone in the past. There was no significant difference in mean BMD values between those who were and those who were not on inhaled steroids in men or women. However, on multivariate analysis, cumulative inhaled steroid dose was associated with a reduction in posterior-anterior (P-A) and lateral lumbar spine bone mineral density in women, equivalent to a 0.11 standard deviation reduction in bone density per 1000 micrograms/day inhaled steroid per year after adjustment for potential confounding factors (95% CI for P-A spine 0.01 to 0.22; for lateral spine 0.02 to 0.21). Previous oral steroid use was not an important confounding factor in these patients. Inhaled steroid use was not related to BMD at the wrist or hip in women or at any skeletal site in men. Women taking an inhaled steroid had lower levels of serum osteocalcin than those not taking them, although this was not dose related. Inhaled steroid use was not associated with differences in other markers of bone metabolism in men or women or with the presence of vertebral fractures.

CONCLUSIONS

Although an effect of confounding factors cannot be excluded entirely in a cross sectional study, our findings are in keeping with an effect of inhaled steroid therapy in reducing bone density in the spine in women and provide an estimate of the magnitude of this effect.

Inflammatory bowel disease and predisposition to osteopenia

The prevalence of osteopenia in children with inflammatory bowel disease (IBD) is unknown. The effect of nutritional state, disease activity, and steroid therapy on bone mineral content (BMC) of whole body, lumbar spine, and left femoral neck measured by dual energy x ray absorptiometry in 32 children with IBD was assessed by comparison with 58 healthy local school children. Using the control data, a predicted BMC was calculated taking into account bone area, age, height, weight, and pubertal stage. The measured BMC in children with IBD was expressed as a percentage of this predicted value (% BMC). Mean (SD) % BMC was significantly reduced for the whole body and left femoral neck in the children with IBD (97.0 (4.5)% and 93.1 (12.0)% respectively, p < 0.05). Of the children with IBD, 41% had a % BMC less than 1 SD below the mean for the whole body and 47% at the femoral neck. Reduction in % BMC was associated with steroid usage but not with the magnitude of steroid dose, disease activity, or biochemical markers of bone metabolism. In conclusion, osteopenia is relatively common in childhood IBD and may be partly related to the previous use of steroids.

Corticosteroid-induced bone loss. Prevention and management

Osteoporosis is one of the most serious adverse effects experienced by patients receiving long term corticosteroid therapy. Bone loss occurs soon after corticosteroid therapy is initiated and results from a complex mechanism involving osteoblastic suppression and increased bone resorption. There are a number of factors that may increase the risk of corticosteroid-induced osteoporosis [smoking, excessive alcohol (ethanol) consumption, amenorrhoea, relative immobilisation, chronic obstructive pulmonary disease, inflammatory bowel disease, hypogonadism in men, organ transplantation]. The initial assessment of patients about to start taking corticosteroids should include measurement of spinal bone density, urinary calcium level and plasma calcifediol (25-hydroxycholecalciferol) level; serum testosterone levels should also be measured when hypogonadism is suspected. Many different drugs have been used to prevent osteoporosis in patients receiving long-term corticosteroid therapy, including thiazide diuretics, cholecalciferol (vitamin D) metabolites, bisphosphonates, calcitonin, fluoride, estrogens, anabolic steroids and progesterone. At present, however, published studies have failed to demonstrate a reduction in the rate of fracture using different preventive pharmacological therapies in patients being treated with corticosteroids on a continuous basis. Among the drugs studied, bisphosphonates (pamidronic acid and etidronic acid) and calcitonin appear to be effective in increasing bone density. Cholecalciferol preparations have been reported to be effective in some, but not all, studies. Limited data have shown positive results with thiazide diuretics, estrogen, progesterone and nandrolone. When treating patients with corticosteroids, the lowest effective dose should be used, with topical corticosteroids used whenever possible. Auranofin may be considered in patients with corticosteroid-dependent asthma. Patients should take as much physical activity as possible, maintain an adequate daily intake of calcium (1000 mg/day0 and cholecalciferol (400 to 800 U/day), stop smoking and avoid excessive alcohol intake. It is important to detect and treat hypogonadism in men, if present, and to replace gonadal hormones in postmenopausal women or amenorrhoeic premenopausal women, and to detect and correct cholecalciferol deficiency. A thiazide diuretic should be considered if hypercalciuria is present (urinary calcium excretion in excess of 4 mg/kg/day). High-risk patients and those with established osteoporosis should be treated with bisphosphonates (cyclical etidronic acid or intravenous pamidronic acid), nasal calcitonin, or calcifediol or calcitriol. Patients receiving cholecalciferol preparations should be carefully monitored for hypercalciuria and hypecalcaemia.

Changes in bone markers in children with asthma during inhaled budesonide and nedocromil treatments

We evaluated serum and urinary markers of bone turnover in 14 children with asthma during inhaled budesonide and nedocromil treatments. Both the markers of formation (serum carboxy- and amino-terminal propeptides of type I procollagen and serum osteocalcin) and the markers of degradation (serum carboxy-terminal telopeptide of type I collagen and urinary pyridinium cross-links) decreased (p < 0.05) during budesonide treatment for 6 months. During inhaled nedocromil treatment (for the following 6 months), the markers returned to the normal levels. These transient decreases in the markers of both formation and degradation of bone suggest that inhaled budesonide may slightly decrease the bone turnover rate. However, normal "coupling" between formation and degradation seemed to operate, e.g. a change in one resulted in a corresponding change in the other, so that net bone loss did not necessarily occur.

Where are we with nuclear medicine in pediatrics?

The practice of nuclear medicine in children is different from that in adults. Technical considerations including immobilization, dosing of radiopharmaceuticals, and instrumentation are of major importance. Image magnification and the capability to perform single-photon emission tomography are essential to performing state of the art pediatric nuclear medicine. New advances in instrumentation with multiple detector imaging, the possibility of clinical positron emission tomography imaging in children, and new radiopharmaceuticals will further enhance pediatric scintigraphic imaging. This review highlights advances in pediatric nuclear medicine and discusses selected clinical problems.

Volumetric bone mineral density--a potential role in paediatrics

The use of areal bone mineral density (aBMD) in paediatric populations has aroused some concern, as it fails to take the age-related increase in bone thickness into account. We have developed a measure of true bone density, volumetric bone mineral density (vBMD), which is independent of age and height. In order to examine the relationship between growth parameters, aBMD and vBMD, we studied patients with phenylketonuria (PKU, n = 40), chronic renal failure (CRF, n = 27) and chronic asthma (n = 19). aBMD of the femoral neck and the mid-femoral shaft was measured using dual energy X-ray absorptiometry (DXA), vBMD was calculated on the basis of values of bone mineral content and bone dimension provided by DXA, with the assumption that both sites are cylinders. aBMD and vBMD were then compared with the normal reference, expressed as a standard deviation score (SDS). aBMD and vBMD were normal in the femoral neck region of the PKU group, but aBMD, either standardized for age or for height, was low in the femoral shaft region (p < 0.01). In the CRF group, profound growth retardation was seen (mean height SDS, -3.2) and aBMD and vBMD were both low in the femoral shaft region but not in the femoral neck. In the asthma group, aBMD for age was low at both sites, but vBMD did not differ from that seen in normal individuals. We conclude that the true vBMD provides a different interpretation of bone density compared with aBMD and requires further evaluation in paediatrics because of its age and height independence.

Cross-sectional study of bone density in asthmatic children

The emphasis in treatment of asthma in children has shifted from bronchodilators to inhaled anti-inflammatory medications, including inhaled corticosteroids (ICS). Children with chronic asthma and moderate to severe symptoms have been targeted as particularly deserving of maintenance therapy with ICS. We have previously reported a cross-sectional study of bone density in children treated with ICS. There was no significant difference between the total bone density of asthmatic patients and controls. We sought to extend the information available on bone density in asthmatic children by evaluating 15 asthmatic subjects taking daily ICS (beclomethasone dipropionate) and comparing them with age- and sex-matched controls. We compared total and regional bone density, bone age, and calcium intakes in these subjects. Asthmatic subjects were on ICS for 4-60 months, with doses ranging from 200 to 450 micrograms/day. There was no significant difference between asthmatics and matched controls for height, weight, % RDA Ca2+, or bone age. The asthmatic subjects had bone density (total and regional measurements) equivalent to their controls. These results provide additional support for the safety of low-dose ICS on bone density in asthmatic children.

Bone mineral density in adolescents

Bone densitometry is becoming more widely available and is no longer limited to studying the elderly. Rapid, safe, and accurate methods of measuring BMD now allow serial determination of this important factor in fracture risk and will undoubtedly become even more accessible in the future. Likewise, our knowledge about the mechanisms and genetics of bone resorption and bone formation is rapidly expanding. Therefore, efforts to prevent osteoporosis in later life by maximizing peak BMD during adolescence and young adulthood must be directed at identifying young people who are at risk because of low body weight, inactivity, inadequate calcium intake, sex hormone deficiency, or because of disease or treatments associated with reduction of BMD. If BMD is found to be low, efforts to enhance bone formation (eg, weight gain, weightbearing exercise, increased calcium intake, and effective treatment of the underlying illness) should be encouraged. Antiresorptive agents, such as sex hormones, should be used cautiously, since they can have significant side effects and may not produce the expected results. Pediatricians must keep in mind the axiom: osteoporosis ... the only cure is prevention.