Bone metabolism in children with asthma treated with nebulized flunisolide: a multicenter italian study

CURRENT THERAPEUTIC RESEARCH® VOL. 59, NO. 12, DECEMBER 1998

BONE METABOLISM IN CHILDREN WITH ASTHMA TREATED WITH NEBULIZED FLUNISOLIDE: A MULTICENTER ITALIAN STUDY PIER L. GIORGI,1 NICOLA 0GGIANO, 1 A.HMAD KANTAR, 1 GIOVANNI V. COPPA, 1 ROBERTO RICCIOTTI,2 FELICE ARENA,3 FILIPPO BERNARDI,4 MARIA L. COLOMBO, 5 MAURIZI0 FANO,e ALBERTO FLORES D'ARCAIS,7 SEBASTIANO GUARNACCIA,s MARIO LA ROSA, 9 FRANCESCO MARCUCCI,l° GIROLAMO PANASCI, a LAURA SENSI, 1° MARIA SPINELLO,5 AND MAURIZIO BIRAGHIe

1Pediatric Clinic, University of Ancona, Ancona, 2Department of Radiochemistry, Italian National Research Center on Aging, Ancona, ZPediatric Clinic, University of Palermo, Palermo, 4Pediatric Clinic, University of Bologna, Bologna, 5Pediatric Division, Orbassano Hospital, Orbassano, 6Medical Department, Valeas Pharmaceuticals, Milan, 7111Pediatric Clinic, University of Milan, Milan, SPediatric Clinic, University of Brescia, Brescia, Spediatric Clinic, University of Catania, Catania, and WDepartment of Pediatrics, University of Perugia, Perugia, Italy ABSTRACT This multicenter, parallel-group, open-label, randomized study was c o n d u c t e d in p r e p u b e r t a l c h i l d r e n w i t h mild a s t h m a t o i n v e s t i g a t e t h e e f f i c a c y a n d i n f l u e n c e o n b o n e a n d c o l l a g e n t u r n o v e r o f a d ai l y r e g i m e n o f f l u n i s o l l d e 1200 llg a l o n e ( g r o u p A, n = 14), f l u n i s o l i d e 600 p g in c o m b i n a t i o n w i t h s o d i u m c r o m o g l y c a t e ( S C G ) 60 mg ( g r o u p B, n = 15), o r SCG 60 mg a l o n e ( g r o u p C, n = 15) f o r 4 m o n t h s . All m e d i c a t i o n s w e r e a d m i n i s t e r e d by m e a n s o f a j e t n e b u l i z e r u s i n g a m o u t h p i e c e . S e r u m o s t e o c a l c i n ( O C ) , b o n e a l k a l i n e p h o s p h a t e (BALP), a n d p r o c o l l a g e n t y p e I c a r b o x y t e r m i n a l p r o p e p t i d e ( P I C P ) w e r e m e a s u r e d as m a r k e r s o f b o n e f o r m a t i o n , a n d t y p e I c o l l a g e n t e l o p e p t i d e ( I C T P ) w a s m e a s u r e d as a m a r k e r o f b o n e r e s o r p t i o n before and after treatment. The efficacy of the t r e a t m e n t schedules w a s a s s e s s e d m e a s u r i n g f o r c e d e x p i r a t o r y v o l u m e in 1 s e c o n d ( F E V l ) a n d t h e u s e o f r e s c u e m e d i c a t i o n . No s i g n i f i c a n t d i f f e r e n c e s w e r e f o u n d in t h e c o n c e n t r a t i o n o f OC, B-ALP, P I CP, o r I C T P between the three t r e a t m e n t groups before the t r e a t m e n t period. In a d d i t i o n , n o s i g n i f i c a n t c h a n g e s w e r e f o u n d a f t e r t h e t r e a t m e n t period, a l t h o u g h a w i d e v a r i a t i o n i n i n d i v i d u a l r e s p o n s e w a s o b s e r v e d in all m a r k e r s . I n t h e g r o u p t r e a t e d w i t h f l u n i s o l i d e 1200 Ilg/d, F EV 1 improved significantly after treatment; no significant improvement in F EV 1 w a s o b s e r v e d in t h e o t h e r t w o g r o u p s. T h e n u m b e r o f child r e n w h o n e e d e d r e s c u e m e d i c a t i o n w a s r e d u c e d t o 14.396 in g r o u p A, 20.096 in g r o u p B, a n d 53.3% in g r o u p C. T h e r e s u l t s o f t h e p r e s e n t s t u d y s u g g e s t t h a t a 4 - m o n t h r e g i m e n o f n e b u l i z e d f l u n i s o l l d e 1200 Ilg/d is e f f e c t i v e in p a t i e n t s w i t h mild a s t h m a a n d d o e s n o t a l t e r b o n e o r c o l l a g e n t u r n o v e r m a r k e r s . H o w e v e r , t h e d i f f e r e n c e s in indiAddress correspondence to: A. Kantar, MD, Pediatric Clinic, University of Ancona, Via Corridoni 11, 1-60123 Ancona, Italy. Receivedfor publication on August 27, 1998. Printed in the USA. Reproduction in whole or part is not permitted. 896

0011-393x/98/$19.00

P. L. GIORGI E T AL.

vidual response to therapy make it necessary to examine further the issues of bone metabolism in flunisolide-treated children with asthma. K e y words: f l u n i s o l i d e , s o d i u m c r o m o g l y c a t e , b o n e markers, asthma.

INTRODUCTION Glucocorticoids (GCs), first-line therapy for most patients with asthma, are now being introduced early in the natural history of the disease in the hope of preventing both short- and long-term complications such as reduced lung function, airway remodeling, and impairment of the normal development of the lung. Although GCs have a variety of activities, their primary therapeutic efficacy is thought to be their anti-inflammatory action. As the role of GCs in a s t h m a management increases, the safety of these drugs is being questioned.l'2 Although inhaled GCs have a much lower potential for systemic effects than oral GCs, the possibility of complications from systemic effects remains in patients receiving long-term therapy. Concerns about such complications sometimes result in undertreatment of childhood asthma. 3 Although early studies of inhaled GCs reported no side effects, recent studies have recommended caution in the use of higher doses or long treatment periods. 3'4 Inhaled GCs have been associated with corticosteroid-like effects on bone metabolism in adults, especially at higher doses. The effects in children remain unclear. Studies of the effect of GCs on bone metabolism are divided between those reporting no effects and those demonstrating significant effects. 1'3 These inconsistent findings m a y reflect the differences in patients, inhaled GC pharmacology, duration of treatment, inhalation methods, and the bone markers evaluated. 5 Moreover, as more sensitive biochemical tests of the systemic effects of GCs on bone metabolism become available, such effects m a y be identified more often; however, identification of new effects does not necessarily mean that the effects will be important clinically. The aim of this study was to investigate the effects of 4 months of t r e a t m e n t with inhaled flunisolide 1200 ~g/d alone, inhaled flunisolide 600 ~g/d in combination with 60 mg/d sodium cromoglycate (SCG), or inhaled SCG 60 mg/d alone on serum markers of collagen and bone turnover in children with asthma. In addition, the efficacy of these treatment regimens was evaluated by measuring forced expiratory volume in 1 second (FEV1) and the use of rescue medication. PATIENTS AND METHODS

Patients

Prepubertal children with mild a s t h m a who used inhaled beta stimulants regularly were eligible for participation in the study. Patients with 897

FLUNISOLIDEAND BONE METABOLISM

any other pulmonary disease, serious concomitant disease, or a history of bone fractures were excluded from participation. Written parental consent was obtained for all participants.

Study Design This multicenter, parallel-group, open-label, randomized study was designed to assess the safety and efficacy of inhaled flunisolide alone or in combination with SCG versus SCG alone in children with mild asthma. The third group (SCG alone) served as a control group. After a 2-week run-in period, patients were randomly assigned to groups and received treatment for 4 months. During the first visit, the research physician recorded the child's medical history and present condition, examined the respiratory tract, measured height and body weight, and performed spirometry. No treatment was given during the 2-week run-in period. At the start of the treatment phase, patients were assigned to one of the following groups: group A, nebulized flunisolide 1200 ~g daily (2 administrations); group B, nebulized flunisolide 600 ;Lg daily (1 morning administration) and nebulized SCG 60 mg daily (3 administrations); or group C, SCG 60 mg daily (3 administrations) (Figure 1). Parents were provided with rescue medication (salbutamol) to be used as required in case of exacerbation. Appropriate jet nebulizers (Soffio Nuovo, Markos, Monza, Italy) were given to all patients. A 2-mL solution was nebulized with a mass median aerodynamic diameter of 2.03 ~m after 10 minutes. Patients were carefully

Treatment

Enrollment

Baseline

2 Month

F i g u r e 1. S t u d y design. (SCG = s o d i u m cromoglycate) 898

3

4

P. L. GIORGI ET AL.

instructed on the inhalation technique using a mouthpiece. Mouth rinsing was recommended after flunisolide inhalation. After the run-in period (baseline), follow-up evaluations were performed after 2, 3, and 4 months. At each visit the research physician examined the respiratory tract, performed spirometry, recorded the use of rescue medication, and assessed compliance with therapy.

L a b o r a t o r y Tests Assay kits for type I collagen telopeptide (ICTP) and procollagen type I carboxyterminal propeptide (PICP) (Orion Diagnostica, Espoo, Finland) used the radioimmunoassay technique. For the PICP kit, 100 ~L of sample serum was mixed with 200 ~L of PICP antiserum and 200 ~L of 125Ilabeled PICP. After incubation at 37 °C for 2 hours, separation reagent was added, and tubes were allowed to stand for 30 minutes at room temperature and then centrifuged. The s u p e r n a t a n t was removed and the sedim e n t containing the precipitated antibody-antigen complex was counted by means of a g a m m a counter (LKB 1261 Multigamma counter, Wallac, Turku, Finland). 6 For the ICTP kit, 100 ~LL of sample serum was mixed with 200 ~L of ICTP antiserum and 200 }~L of 125I-labeled ICTP. Separation reagent was added after incubation for 2 hours; tubes stood for a short while and were then centrifuged. Subsequently, the s u p e r n a t a n t was removed and the sediment containing the precipitated antibody-antigen complex was counted using a g a m m a counter. 7 Osteocalcin (OC) and bone alkaline phosphate (B-ALP) were determined using an immunoradiometric assay (Nichols Institute Diagnostics, San J u a n Capistrano, California and Hybritech, Liege, Belgium, respectively). For assay of OC, 200 ~L of 125I-labeled OC antibody was added to a labeled tube with 10 ~LL of serum. After vortexing, one bead was added to the sample, which was then incubated at room temperature for 3 hours on a horizontal rotator set at 180 to 220 rpm. The contents of the tube were aspirated, and the bead was washed three times. The tube was placed in a g a m m a counter for 1 minute, s For assay of B-ALP, 100 ~L of tracer antibody was added to the test tube containing 100 }xL of serum, and the reagents were mixed by shaking the tube rack by h a n d for 15 seconds. One bead was added to the sample. After mixing, the sample was incubated overnight in a cold room (4 °C). The bead was washed three times. After aspiration, the tube was placed in a g a m m a counter. 9

Statistical Analysis Statistical comparisons of the bone markers were carried out in and between groups using paired and unpaired Student t tests, respectively. The 95% confidence intervals were also calculated for changes in the pa899

FLUNISOLIDEAND BONE METABOLISM

rameters within the groups. Multiple comparisons with baseline values in each treatment group were carried out according to the Dunnett test using the error mean square variance obtained by two-way analysis of variance. The chi-square test was used to evaluate statistical differences in the number of patients using rescue medication.

RESULTS

Forty-eight prepubertal children (28 boys and 20 girls) 6 to 11 years of age were included in the study. Table I shows the baseline characteristics of the 44 patients who were randomly assigned to the three treatment groups and not excluded from statistical analysis. Four patients (3 girls and 1 boy) were excluded because of poor compliance and/or use of oral GCs. No significant differences were found in the concentrations of ICTP, PICP, OC, or B-ALP between the three groups before treatment (Table II). In addition, no significant changes were found in the bone markers in any group after 4 months of treatment (Figure 2 and Table II). In group A (flunisolide 1200 ~g/d), a statistically significant improvement in FEV1 was seen after 3 months of treatment and was still present after 4 months. No significant improvements were observed in the other two groups (Figure 3). During the wash-out period and the first 2 months of treatment, all patients used rescue medication (salbutamol). During month 3 and month 4

Table I. Baseline characteristics of p a t i e n t s w h o w e r e included in t h e statistical analysis,* by t r e a t m e n t group.

Flunisolide 1200 pg/d (n = 14) Sex, n (%) Male Female Age Mean Range Duration of asthma (y) Mean Range No. (%) of patients who tested positive for allergy Baseline FEV1 (L)t Theoretical FEV1 (L)t No (%) of patients using salbutamol during the wash-out period

Flunisolide 600 pg/d + SCG 60 mg/d SCG 60 mo/d (n = 15) (n = 15)

9(64) 5 (36)

11 1731 4

6(40) 9 (60)

8.5 7-10

8.6 6-11

8.4 6-10

4.9 3-7

4.8 3-7

4.4 2-7

10 (71) 1.53 + 0.12 1.71 + 0.10

9 (60) 1.65 + 0.15 1.80 + 0.11

10 (67) 1.60 + 0.12 1.76 + 0.13

14 (100)

15 (100)

15 (100)

SCG = sodium cromoglycate; FEV1 = forced expiratory volume in 1 second. Four patients (3 girls, 1 boy) were excluded becauseof poor compliance and/or use of oral glucocorticoids. t Mean + SE. 900

P. L. GIORGI E T AL.

Table II. Mean serum concentrations and concentration changes in type I collagen telopeptide (ICTP), procollagen type I carboxyterminal propeptide (PICP), osteocalcin (OC), and bone alkaline phosphate (B-ALP) in patients who were included in the statistical analysis,* by treatment group. (All values are expressed in ng/mL.)

ICTP Before treatment (mean + SE) Mean change after treatment 95% confidence interval PICP Before treatment (mean + SE) Mean change after treatment 95 ° confidence interval OC Before treatment (mean ± SE) Mean change after treatment 95% confidence interval B-ALP Before treatment (mean ± SE) Mean change alter treatment 95% confidence interval

Runisolide 1200 pg/d (n = 14)

Flunisollde 600 pg/d + SCG 60 mg/d (n = 15)

SCG 60 mg/d (n = 15)

13.64 + 0.93 -0.43 -3.67-2.81

14.26 + 0.87 -1.06 -1.28-3.50

13.23 + 0.71 +0.64 -1.17-3.20

407.7 + 31.33 +10.64 -72.08-93.37

423.27 ± 31.50 -5.73 -43.78-119.93

394.33 ± 25.71 -21.13 -46.06-126.18

23.20 * 3.21 -0.83 -9.06-7.40

21.81 ± 1.78 -2.92 -2.60-7.12

20.61 ± 3.49 +1.79 -4.04-11.05

81.15 * 4.94 -0.69 -16.95-15.56

66.93 ± 4.53 +4.90 -5.59-15.31

71.51 ± 6.63 +1.00 -4.29-11.74

SCG = sodium cromoglycate. * Four patients (3 girls, 1 boy) were excluded because of poor compliance and/or use of oral glucocorticoids.

of treatment, the number of patients using rescue medication in group A was reduced to 7.1% and 14.3%, respectively, in group B to 26.7% and 20.0%, respectively, and in group C to 53.3% in both months (Table III).

DISCUSSION Although the benefits of inhaled steroids in asthma therapy are clear, systemic effects of inhaled GCs show cause for concern, particularly because these drugs are likely to be used for long-term therapy. 2 To date, few studies have assessed the clinical relevance of detectable systemic effects, which depend on several factors, including the dose administered, systemic bioavailability, pharmacokinetics, and differences in steroid response in different patients. 5 Flunisolide has demonstrated potent GC and w e a k mineralocorticoid activity in classic animal test systems. The drug is several hundred times more potent than the cortisol standard. Following administration offlunisolide to humans, approximately half of the administered dose is recovered in urine and half in stool; 65% to 70% of the dose recovered in urine is the primary metabolite, which has lost a 6-alpha fluorine and added a 6-beta hydroxy group, l° Flunisolide is well absorbed; however, it is converted 901

FLUNISOLIDE AND BONE METABOLISM

..J

0,. I'--

1000 800 ,,--I

600 r0-

400

0.

200 0

50 40 30

o 0

20 I0 0

160 ,,-I

120

C

90

o.. ..I

00

CO

30 0

Flunisolide 1200 pgld

Flunisolide 600 po/d + SC6 60 mold

SCG 00 mgld

Figure 2. Individual serum concentrations of type I collagen telopeptide (ICTP), procollagen type I carboxyterminal propeptide (PICP), osteocalcin (OC), and bone alkaline phosphate (B-ALP) before and after treatment with inhaled flunisolide (1200 ~g/d), flunisolide (600 ~g/d) in combinationwith sodium cromoglycate (SCG) (60 rag/d), or SCG (60 rag/d) alone. (Heavy line indicates the median value.) 902

P. L. GIORG] ET AL.

20 18 lS 14 12 1D 8 S 4 2 0

Runisolide 12QD p,gl~ F'~niselide 60O ~ d + SCG 60 mg/d

IN

~f~.~ ~ior~t~ ~

SCG60 mg/d

Figure 3, Mean changes in forced expiratory volume in 1 second (FEVz) expressed as percentage of baseline values during the treatment period in the three groups. *P ~< 0.01, tP ~<0.05. (SCG = sodium cromoglycate)

rapidly by the liver to the less active primary metabolite and to glucurohate or sulfate conjugates. Because of first-pass hepatic metabolism, only 20% of flunisolide reaches the systemic circulation when given orally. Aider inhalation of 1 mg flunisolide, total systemic availability is 40%. The flunisolide t h a t is swallowed is rapidly and extensively converted to the 6-beta hydroxy metabolite and to water-soluble conjugates during the first pass through the liver. This effect offers a metabolic explanation for the low systemic activity of oral flunisolide because the metabolite has low corticoid potency (with respect to the cortisol standard). The inhaled flunisolide absorbed through the bronchial tree is converted to the metabolites,

Table III. Number (%) of patients who were includedin the statistical analysis* and using rescue medicationduring the study period, by treatment group.

Wash-out period Baselineto month 2 Month 4

Flunisnlide 1200 pg/d (n : 14)

Flunisolide 600 pg/d + SCG 60 mo/d (n = 15)

SCG 60 mg/d (n = 15)

14110~001 14

15 II~00t 15

15/~O0~/ 15

2

3 (20.0)

8 (53,3)

SCG = sodium crornoglycate. * Four patients (3 gids, 1 boy) were excludedbecauseof poor complianceand/or use of oral glucocorticoids.

903

FLUNISOLIDE AND BONE METABOLISM

The plasma half-life offlunisolide is approximately 1.8 hours, whereas the half-life of 6 beta-hydroxyflunisolide is approximately 4 hours. The bioavailability of inhaled corticosteroids results from a combination of the oral (swallowed fraction) and lung components. The amount of drug delivered by a jet nebulizer varies from 2% to 10%; drug deposition in the mouth is estimated to be 5% to 10%. 11 Thus the effective daily bioavailability of the drug used in this study was estimated to be about 84 to 240 }xg in group A and 42 to 120 ~g in group B. Whether a systemic effect is measurable or not depends on the sensitivity of the method used; when more sensitive methods are developed, more systemic effects will become measurable. Plasma cortisol, urinary cortisol, and response to synthetic adrenocorticotropic hormone have been used as end points in the safety assessment of inhaled steroids. Alternative markers, such as bone markers, lower leg length, and bone density, have been proposed and are the subject of ongoing clinical research. 3 Various s t u d i e s 12-16 have demonstrated that nebulized flunisolide is effective in the treatment of asthma. Moreover, at dosages of 800 to 1600 ~g/d, flunisolide did not induce significant suppression of the hypothalamic-pituitaryadrenal axis. 17'1s To our knowledge, no studies have evaluated the influence of inhaled flunisolide on bone metabolism. GCs reduce bone mass directly by inhibiting bone formation, and indirectly by inhibiting the secretion of androgen in the pituitary-gonadal and adrenal systems and by limiting calcium absorption in the intestines and calcium reabsorption in the renal tubules, thereby causing secondary hyperparathyroidism. 19 Oral GC therapy is a well-known cause of osteoporosis and an increased risk factor for vertebral and rib fractures; however, no reports have suggested that treatment with inhaled GCs is associated with an increased risk of fractures. 1'2° Several biochemical markers have been used to assess the effect of inhaled GCs on bone metabolism. 21-24 Levels of all markers of bone formation and resorption are normally measurable, because normal bone is in a constant state of turnover, while maintaining a balance between resorption and formation. An elevation of all markers could occur when increased bone turnover is without net loss or gain, whereas a decline of all markers could signify a reduction in bone turnover with a constant bone mass. Serum OC, considered a marker of bone formation, is a noncollagen protein synthesized primarily by osteoblasts. PICP, a trimetric globular protein, is removed by specific proteinases before collagen molecules are assembled into fibers. Procollagen propeptides are released into circulation in a stoichiometric 1:1 ratio with the collagen molecules formed. Therefore, measurement of PICP allows us to study the synthesis of new bone. B-ALP is a tetrametric glycoprotein found on the cell surface of osteoblasts, which are the cells responsible for new bone formation. The func904

P. L. GIORGI ET AL.

tion of B-ALP is not understood clearly, although it m a y play a role in skeletal mineralization. Membrane-bound tetrametric B-ALP is released into circulation as a dimer by phospholipase cleavage. Serum levels of B-ALP are believed to reflect the metabolic status of osteoblasts. 21 ICTP is a marker of bone degradation; the carboxyterminal telopeptide region of type I collagen is liberated during degradation of the collagen fibrils. Because the serum concentration of ICTP was found to be correlated with the cancellous bone resorption rate, as measured by histomorphometry, serum ICTP is considered to be a specific marker of bone resorption. 1'2~26 The serum concentrations of bone markers obtained in the present study are similar to those reported in other studies. Although no follow-up data are reported in healthy prepubertal children, it is known that in elderly patients one cycle of physical therapy is enough to modify bone marker concentrations. 9 In the present study, two different nebulized flunisolide regimens-1200 ~g/d alone or 600 ~g/d in combination with 60 mg/d of SCG--were investigated. The former treatment regimen is the one used most often for children with asthma, whereas the latter regimen represents an effort to use the lowest dosage of flunisolide that will control the disease. Based on the assessment of FEV1 and the use of rescue medication, our results suggested that flunisolide 1200 ~g/d was more effective in controlling asthma than the other two regimens. Zu Wallack et a127 recently reported deterioration in asthma control after switching to oncedaily administration of flunisolide in patients who were controlled by twice-daily administration. Although our results did not demonstrate equivalent treatment efficacy in groups A and B, the combination of SCG and once-daily administration of flunisolide could be used in the treatment of mild a s t h m a if control is not maintained by SCG alone. Bone metabolic markers did not show significant changes in the three groups after therapy. However, a wide variation in individual response was observed in all markers. Such alterations are also evident in other studies in which the same variables were investigated using different corticosteroids. 21'2s Although different individual responses to corticosteroid therapy could partially explain the response in the flunisolide group, the significance of the changes in the SCG group is still unclear. Similar variations in individual concentrations of carboxy- and aminoterminal propeptide of type I and the aminoterminal propeptide of type II procollagen (PICP, PINP, and PIIINP, respectively) have been reported recently in patients with asthma treated with inhaled nedocromil 16 mg]d. 2s These data 1'4 indicate that the bone markers m a y be influenced by other factors, including physical activities, lifestyle, and diet. Thus these variables, when used alone, might be less sensitive in evaluating changes in bone metabolism over long periods. Moreover, assessment of the effects of inhaled GCs on bone is complicated in patients with asthma, because many patients 905

FLUNISOLIDEAND BONEMETABOLISM

have previously received short-course therapy with oral GCs t h a t may have resulted in residual structure abnormalities. Asthma itself m a y affect bone metabolism through effects on lifestyle (less exercise, different dietary habits). Furthermore, no data are available on the sensitivity of serum OC, PICP, ICTP, and B-ALP as bone markers of osteoblast and osteoclast activity in children. 29 In adults, most bone formation occurs as part of a continuous remodeling of bone and only to a limited extent as part of skeletal growth (modeling). In contrast, modeling is the major activity of the skeleton in children, whose bone mass increases throughout childhood. Serum OC m a y be a less sensitive m a r k e r of the effects of inhaled GCs on osteoblasts t h a t are engaged mainly in bone modeling in children. At present, the influence of inhaled corticosteroids on c-propeptide collagen type I and urinary pyridinium cross-links has not been studied, whereas the effects on other markers have been studied to some extent in children and adults. The relevance of effects of inhaled GCs on bone metabolism is debatable. 1-4 The clinical diagnosis of bone mass alterations m a y be assessed by in vivo measurements of bone density. 28-3° This assay could offer a sensitive method for long-term studies r a t h e r t h a n for shortterm investigations; however, recent studies 3°'31 did not demonstrate alterations in bone mass after inhaled GC therapy. Although the analysis of the data obtained in the present study did not show a mean effect on any group with respect to bone metabolism, the differences among individuals make it necessary to examine further the issue of bone metabolism in steroid-treated children with asthma.

CONCLUSION Results of the present study suggest t h a t t r e a t m e n t with nebulized flunisolide at dosages of 1200 ~g/d for 4 months is effective in patients with mild a s t h m a and does not suppress bone or collagen turnover markers. However, the possibility of individual variations in response to a s t h m a therapy cannot be ignored. Short-term studies could be used to assess whether m a n y variables thought to play a role in bone metabolism actually do so. F u r t h e r studies are needed to clarify the effects of inhaled GCs on bone metabolism.

Acknowledgment This study was supported by Valeas Pharmaceuticals, Milan, Italy. References: 1. Kamada AK, Szefler SJ, Martin RJ, et al. Issues in the use of inhaled glucocorticoids. Am J Respir Crit Care Med. 1996;153:1739--1748. 906

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2. Pederson S, O'Byrne P. A comparison of the efficacy and safety of inhaled corticosteroids in asthma. Allergy. 1997;52(Suppl 39):1-34. 3. Barnes PJ, Pederson S. Efficacy and safety of inhaled corticosteroids in asthma. Am Rev Respir Dis. 1993;148(Suppl 4):$1-$26. 4. Barnes PJ. Inhaled glucocorticoids for asthma. NEJM. 1995;332:868-875. 5. Johnson M. Pharmacodynamics and pharmacokinetics of inhaled glucocorticoids. J Allergy Clin Immunol. 1996;97:169-176. 6. Risteli J, Elomaa I, Niemi S, et al. Radioimmunoassay for the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen: A new serum marker of bone resorption. Clin Chem. 1993;39:635-640. 7. Melko J, Niemi S, Risteli J. Radioimmunoassay of the carboxyterminal propeptide of human type I procollagen. Clin Chem. 1990;36:1328--1332. 8. Bouillon R, Vanderschueren D, Van Herck, E, et al. Homologous radioimmunoassay of human osteocalcin. Clin Chem. 1992;38:2055-2060. 9. Ricciotti R, Gemini R, Foschi F, et al. Physical activity and biochemical markers of bone turnover in elderly patients. Arch Gerontol Geriatr. 1997;26:49-53. 10. Chaplin MD, Rooks W II, Swenson EW, et al. Flunisolide metabolism and dynamics of a metabolite. Clin Pharmacol Ther. 1980;27:402-413. 11. Battistini A. Come attuare el meglio la terapia aerosolica. Parte 1-Le metodiche. Pediatr Med Chir. 1995;17:97-103. 12. De Benedictis FM, Martinati LC, Solinas LF, et al. Nebulized flunisolide in infants and young children with asthma. Pediatr Pulmonol. 1996;21:310-315. 13. Konig P, Shatley M, Levine C, Mawhinney TP. Clinical observations of nebulized flunisolide in infants and young children with asthma and bronchopulmonary dysplasia. Pediatr Pulmonol. 1992;13:209-214. 14. Eisenborg J. The use of nebulized flunisolide in infants and children with asthma and bronchopulmonary dysplasia. Am Rev Respir Dis. 1990;141:899. Abstract. 15. Chin T, Nussbaum E. Use of nebulized flunisolide in pediatric asthma. Am Rev Respir Dis. 1991;143:624. Abstract. 16. Meltzer EO, Kemp JP, Orgel HA, Izu AE. Flunisolide aerosol for treatment of severe chronic asthma in steroid-independent children. Pediatrics. 1982;69:340-345. 17. Piacentini GL, Sette L, Peroni DG, et al. Double-blind evaluation of effectiveness and safety of flunisolide aerosol for treatment of bronchial asthma in children. Allergy. 1990; 43:612-616. 18. Giorgi PL, Oggiano N, Biraghi M, Kantar A. Effect of high doses of inhaled flunisolide on hypothalamic-pituitary-adrenal axis function in children with asthma. Curr Ther Res. 1991;49:778-783. 19. Hosking DJ. Effects of corticosteroids on bone turnover. Respir Med. 1993;87(Suppl A): 15-23. 20. Ward MJ. Inhaled corticosteroids---effect on bone? Respir Med. 1993;87(Suppl A):33-35. 21. Konig P, Hillman L, Cervantes C, et al. Bone metabolism in children with asthma treated with inhaled beclomethasone dipropionate. J Pediatr. 1993;122:219-226. 907

FLUNISOLIDEANDBONEMETABOLISM

22. Wolthers OD, Riis BJ, Pederson S. Bone turnover in asthmatic children treated with oral prednisone or inhaled budesonide. Pediatr Pulmonol, 1993;16:341-346. 23. Bootsma GP, Dekhuijzen PN, Festen J, et al. Fluticasone propionate does not influence bone metabolism in contrast to beclomethasone dipropionate. A m J Respir Crit Care Med. 1996;153:924-930. 24. Boyd G. Effect of inhaled corticosteroids on bone. Respir Med. 1994;88(Suppl A):45-52. 25. Kreipe RE. Bones of today, bones of tomorrow. Am J Dis Child. 1992;146:22-25. 26. Consensus Developmental Conference Report. Prophylaxis and treatment of osteoporosis. Am J Med. 1991;90:107-110. 27. Zu Wallack RL, Rosen JP, Cohen L, et al. The effectiveness of once-dally dosing of inhaled flunisolide in maintaining asthma control. J Allergy Clin Imrnunol. 1997;99:278--285. 28. Autio P, Karjalainen J, Risteli L, et al. Effects of an inhaled steroid (budesonide) on skin collagen synthesis of asthma. Am J Respir Crit Care Med. 1996;153:1172-1175. 29. Chestnut CH. Noninvasive methods for bone measurement. In: Avioli LV, ed. The Osteoporotic Syndrome. New York: Wiley-Liss; 1993:77-87. 30. Martinati LC, Bertoldo F, Gasperi E, et al. Effect on cortical and trabecular bone mass of different anti-inflammatory treatments in preadolescent children with chronic asthma. Am J Respir Crit Care Med. 1996;153:232-236. 31. Baraladi E, Bollini MC, De Marchi A, ZaccheUo F. Effect of beclomethasone dipropionate on bone mineral content assessed by x-ray densitometry in asthmatic children: A longitudinal evaluation. Eur Respir J. 1994;7;710-714.

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