Ultrasound of skin in prednisolone-induced short-term growth suppression

The timing of administration of exogenous glucocorticoid affects 24hour growth hormone secretion in children

Exogenous glucocorticoids may suppress linear growth by affecting the diurnal secretory rhythm of GH.

OBJECTIVE

To assess whether the timing of exogenous glucocorticoid administration affects GH secretion in children.

DESIGN

Four girls and four boys aged 10.6 to 15.8 (mean 13.2) years with normal weight and height and pubertal stages I-IV were studied in an open randomized 2-period cross-over trial, with a 1-day un-in, and two 4-day periods of 5mg prednisolone in the morning or in the evening, respectively, separated by a 3-week washout period. At run-in and on the last day of each treatment period serum was collected every 20min for 24h for assessment of GH. Secondary analyses were serum levels of IGF-I and IGFBP-3 (measured every 8h), and IGFBP-1, insulin, and collagen markers PICP, PINP, ICTP and PIIINP (measured every 2h).

RESULTS

Evening prednisolone suppressed 24hour GH secretion (P=0.016), overnight GH secretion (P=0.023) and IGF-I (P=0.024) when compared to morning prednisolone, but not when compared to run-in. Evening prednisolone also increased nocturnal insulin levels as compared to run-in (P=0.010). Irrespective of time of day, prednisolone increased serum collagen markers PICP, PIINP, ICTP and PINP (all P<0.05).

CONCLUSIONS

Short-term prednisolone 5mg administered in the morning may alleviate nocturnal GH suppression as compared to evening administration. In analogy, growth rates are less affected by morning as compared to evening administration of exogenous glucocorticoids. In contrast, collagen markers and metabolic indices were not affected by the timing of prednisolone administration.

Prednisolone reduces the ability of serum to activate the IGF1 receptor in vitro without affecting circulating total or free IGF1

OBJECTIVE

End-point bioassays based on thymidine or sulfate incorporation have demonstrated that glucocorticoid (GC) treatment inhibits serum IGF1 action, but the mechanism is unknown as serum IGF1 concentrations have been reported to either increase or remain unchanged.

AIM

To investigate whether GC treatment affects the ability of serum to activate the IGF1 receptor (IGF1R) in vitro (i.e. bioactive IGF1), using a specific cell-based IGF1 kinase receptor activation assay.

SUBJECTS AND METHODS

Twenty children with stable asthma (age 7.7-13.8 years) treated for 1 week with 5 mg prednisolone in a randomized, double-blind, placebo-controlled crossover study. Non-fasting serum samples were collected in the afternoon after each 7-day period and assayed for bioactive IGF1, free IGF1, total IGFs, IGF-binding proteins (IGFBPs), and insulin.

RESULTS

Prednisolone treatment reduced IGF1 bioactivity by 12.6% from 2.22±0.18 to 1.94±0.15 μg/l (P=0.01) compared with placebo. In contrast, no changes were observed for (μg/l; placebo vs prednisolone) total IGF1 (215±27 vs 212±24), free IGF1 (1.50±0.16 vs 1.43±0.17), total IGF2 (815±26 vs 800±31), IGFBP3 (3140±101 vs 3107±95), IGFBP2 (238±21 vs 220±19), IGFBP1 (32±6 vs 42±10), or IGFBP1-bound IGF1 (24±5 vs 26±7). Insulin remained unchanged as did IGFBP levels as estimated by western ligand blotting. Prednisolone had no direct effects on IGF1R phosphorylation.

CONCLUSIONS

Our study gives evidence that GC treatment induces a circulating substance that is able to inhibit IGF1R activation in vitro without affecting circulating free or total IGF1. This may be one of the mechanisms by which GC inhibits IGF1 action in vivo. However, the nature of this circulating substance remains to be identified.

Growth suppression caused by corticosteroid eye drops

Scarce data on systemic activity of corticosteroid eye drops are available in children. Two weeks treatment with fluorometholone eye drops in a case series of five children caused growth suppression detected by knemometry. The suppression had no impact on height growth during the following year.

Methodology and implications of knemometry in growth assessment of inhaled glucocorticoids

When validated recommendations for standardization and measurement procedures are used short-term assessment of lower leg growth by knemometry is a highly accurate and reproducible method for assessment of systemic activity of inhaled glucocorticoids. Crossover and parallel designs applying consistent measurement intervals can be used. Crossover designs with a single-blind run in and washout and double-blind active periods are as sensitive as designs using randomized placebo periods. In populations of children, short-term knemometry appears to be capable of defining specific glucocorticoids, application devices and doses that do not suppress long-term height growth. Although no specific cut-off level can be identified in individuals from the available randomized, double-blind short-term knemometry and intermediate-term height growth rate studies, good evidence have been provided that if the short-term lower leg growth suppression in populations of children is higher than approximately 25%, the risk of intermediate-term growth suppression becomes significant with a mean height growth rate retardation in the range of approximately 0.5-1.5 cm during the first year of treatment. Short-term knemometry should be performed as an integral part of the safety assessments of new inhaled glucocorticoids and inhalation devices in children with asthma, before intermediate-term height growth evaluations are initiated.

Short-term growth and adrenal function in children with asthma treated with inhaled beclomethasone dipropionate hydrofluoroalkane-134a

Inhaled beclomethasone dipropionate (BDP) with the propellant hydrofluoroalkane-134a (HFA) has been designed to be equivalent in terms of safety to chlorofluorocarbon (CFC)-formulated metered dose inhalers (MDI). The aim was to assess whether BDP HFA MDI 100 microg twice daily was equivalent to BDP CFC MDI 100 microg twice daily in terms of effects on short-term lower leg growth rate (LLGR) and measures of hypothalamic-pituitary-adrenal (HPA) function. The study consisted of a randomized double-blind cross-over trial with three active, a run-in and two wash-out periods each consisting of 2 wk. The place of study was a secondary referral outpatient clinic. The subjects involved were 14 boys and 10 girls with asthma, aged 7-12 yr. They were all administered BDP HFA 100 microg, BDP CFC 100 microg and 200 microg twice daily. The outcome measures included LLGR and 24-h urine-free cortisol (UFC) and total cortisol metabolites (TCM). Mean (SD) LLGR during run-in and BDP HFA 100 microg, BDP CFC 100 microg and 200 microg twice daily periods were 0.43 (0.23), 0.09 (0.29), 0.10 (0.45) and 0.08 (0.27) mm/wk. The one-sided 97.5% confidence interval for the difference in LLGR between BDP HFA 100 microg and BDP CFC 100 microg was 0.24, thus, below the predefined criterion of 0.20 mm/week. Inter-period comparisons of active treatments showed no differences between means of LLGR, UFC or TCM. Though non-inferiority between BDP HFA and CFC 100 microg twice daily in terms of effects on LLGR was not found, equivalence was suggested by comparisons of LLGR during run-in and active treatments and by HPA function measures.

Short-term lower leg growth in asthmatic children treated with inhaled beta2-agonists

BACKGROUND

Knemometry studies of growth suppressive effects of inhaled glucocorticoids in children with asthma usually allow participating children to use concomitant inhaled beta2-agonists. Systemic beta2-agonists, however, have been found to suppress growth hormone secretion and this has caused concern about a possible confounding effect of inhaled beta2-agonists on results of growth studies of exogenous glucocorticoids.

AIM

The study evaluated whether inhaled salbutamol adversely affects short-term growth.

SUBJECTS AND METHODS

Fifteen children aged 6-12 years with mild asthma were enrolled in a single-blind, randomized crossover study with two 2-week treatment periods and a 1-week run-in. During the active period treatment dry powder salbutamol (Ventoline Diskhaler) 200 microg was inhaled three times a day. During the comparative period no treatment was given. Knemometry of the right lower leg was performed on the first and the last day of each period.

RESULTS

Mean lower leg growth rates (SEM) during no-treatment and salbutamol periods were 0.35 (0.06) and 0.42 (0.07) mm per week, respectively (P = 0.35, t = -0.98, 95% CI: 0.25-0.93 mm per week).

CONCLUSIONS

Inhaled salbutamol 200 microg three times daily does not suppress short-term growth in asthmatic children. Inhaled beta2-agonists in equipotent doses and regimens can be safely used in short-term knemometric growth studies of exogenous glucocorticoids without any risk of confounding the results.

Short-term growth after withdrawal of exogenous glucocorticoids

BACKGROUND

The growth-suppressive effect of systemic glucocorticoids in children is well established, however, recovery of growth after withdrawal of short-term treatment in school-age children has not been evaluated.

OBJECTIVE

To assess short-term growth after withdrawal of systemic glucocorticoids.

METHODS

A post-hoc analysis of data from a double-blind lower leg growth trial which compared 5 mg prednisolone once daily in the evening with placebo was performed. The study consisted of run-in, treatment, wash-out and run-out periods of 1 week duration. In 10 children with asthma (mean age 11 years) lower leg growth measured with the knemometer could be studied up to 3 weeks after withdrawal of prednisolone.

RESULTS

Mean (SEM) lower leg growth rates during run-in, prednisolone treatment and the first, second and third weeks after withdrawal of prednisolone were 0.48 (0.15), -0.27 (0.20), 0.53 (0.19), 0.72 (0.16) and 0.66 (0.14) mm/week, p < 0.001. Mean growth rates during run-in and the first, second and third weeks after withdrawal of prednisolone did not vary, p = 0.68.

CONCLUSION

Recovery of suppressed lower leg growth rates occurs within a week after withdrawal of exogenous glucocorticoids.

Changes in body water distribution during treatment with inhaled steroid in pre-school children

PRIMARY OBJECTIVE

The study aimed to examine the changes in water distribution in the soft tissue during systemic steroid activity.

RESEARCH DESIGN

A three-way cross-over, randomized, placebo-controlled, double-blind trial was used, including 4 weeks of fluticasone propionate pMDI 200 microg b.i.d. delivered via Babyhaler, budesonide pressurized metered dose inhaler (pMDI) 200 microg b.i.d. delivered via Nebuchamber and placebo. Spacers were primed before use. In total, 40 children aged 1-3 years, with mild intermittent asthma were included. Twenty-five of the children completed all three treatments. At the end of each treatment period body impedance and skin ultrasonography were measured.

METHODS AND PROCEDURES

We measured changes in water content of the soft tissues by two methods. Skin ultrasonography was used to detect small changes in dermal water content, and bioelectrical impedance was used to assess body water content and distribution.

MAIN OUTCOMES AND RESULTS

We found an increase in skin density of the shin from fluticasone as measured by ultrasonography (p = 0.01). There was a tendency for a consistent elevation of impedance parameters from active treatments compared to placebo although overall this effect was not statistically significant (0.1 < p < 0.2). However, sub-analyses indicated a significant effect on whole-body and leg impedance from budesonide treatment (p < 0.05).

CONCLUSION

Decreased growth during inhaled steroid treatment seems to partly reflect generalized changes in body water.

Lower leg growth suppression caused by inhaled glucocorticoids is not accompanied by reduced thickness of the cutis or subcutis

BACKGROUND

Exogenous glucocorticoids suppress short-term lower leg growth in children as assessed by knemometry. The knemometric measurements, however, may be confounded by reductions in the thickness of the cutis and subcutis over the knee.

AIM

To assess whether inhaled glucocorticoid-induced suppression of short-term growth is accompanied by changes in the thickness of the cutis and subcutis.

METHODS

The study was a randomized, controlled, crossover trial with 1 wk treatment, run-in and washout periods. Active treatment was inhaled budesonide 200 microg twice daily. Short-term growth was assessed by knemometry, and the thickness of the cutis and subcutis over the knee, on the volar forearm and abdomen was measured by 20 MHz B-mode ultrasound.

MATERIAL

Nineteen children with asthma aged 7 to 13 y.

RESULTS

Lower leg growth was significantly reduced during budesonide treatment (0.27 mm/wk) compared to the treatment-free period (0.54 mm/wk) (p = 0.02, 95%: -0.50 to -0.05). Variations in the thickness of the cutis were seen during budesonide treatment (mean +/- SEM): -0.01 +/- 0.03 mm over the knee, -0.02 +/- 0.02 mm on the forearm and 0.01 +/- 0.02 mm on the abdomen. The variations in the total thickness of the cutis and subcutis were -0.05 +/- 0.12 mm, 0.06 +/- 0.12 mm and -0.06 +/- 0.10 mm during budesonide treatment. The variations in thickness of the cutis or subcutis were not statistically different during budesonide treatment and the treatment free period in any anatomical location.

CONCLUSIONS

Short-term lower leg growth suppression induced by inhaled glucocorticoids is not confounded by variations in thickness of cutis or subcutis. The present observations further establishes knemometry as a reliable tool for assessment of the risk of growth suppression of inhaled glucocorticoids in children with asthma.