Corticosteroid use and bone mineral accretion in children with asthma: effect modification by vitamin D

Effect of long-term medium to high-dose inhaled budesonide on bone mineral density in children with asthma: a cross-sectional study

OBJECTIVE

The objective of this study was to examine the impact of long-term medium to high-dose inhaled budesonide on bone mineral density in children with asthma.

METHODS

We conducted a cross-sectional study in children aged 7-17 years with asthma, who received long-term (≥2 years), medium to high-dose inhaled budesonide (≥400μg/day in 6-11 years old; ≥800 μg/day in >11 years old). We measured bone mineral density (BMD) using dual-energy X-ray absorptiometry and compared it with reference Indian normative values.

RESULTS

Thirty-five children with moderate to severe asthma receiving long-term medium to high-dose inhaled budesonide, were included in the study. We found a significantly low lumbar-spine BMD in the study population compared to reference Indian values (p-value 0.002). Eight cases had short stature. Despite the adjustment for height-age in these short-stature cases, lumbar-spine BMD remained significantly low in the study population (p-value 0.020). No significant difference was found in 25-hydroxy vitamin D levels between subjects with "low BMD" and "BMD z-score > -2".

CONCLUSIONS

The findings of this study suggest that long-term medium to high-dose inhaled budesonide treatment in children with asthma is associated with decreased BMD. However, further investigation with a larger sample size is necessary to confirm this relationship.

Does vitamin D deficiency in asthma affect clinical and functional parameters? A Turkish multicenter study

Background: In recent years, interest in the effects of vitamin D on human health and the immune system has increased. Objective: This study aimed to investigate the relationship of vitamin D with asthma severity, attacks, and clinical and functional parameters in adult patients with asthma who were living in different geographic regions in Turkey. Methods: A total of 384 patients with stable asthma and 87 control subjects were included. A physical examination and a pulmonary function test were performed, and routine blood analyses and vitamin D levels were evaluated. Asthma Control Test was applied. The number of exacerbations in the previous year, asthma therapy, and medication adherence were recorded. Results: In our study, vitamin D levels were below the target values in both patients with asthma (median [minimum-maximum] 16.0 ng/mL [3.5-48 ng/ml]) and control subjects (median [minimum-maximum] 20.0 ng/mL [5.8-58.79 ng/mL]). However, it was lower in the patients with asthma than in the control subjects (p = 0.001). There was a negative relationship between the levels of vitamin D and the severity of asthma (Kendall τ = -0.146; p < 0.001). Furthermore, the patients with severe asthma were received The Global Initiative for Asthma (GINA) step 5 treatment showed significantly lower vitamin D compared with the patients who received GINA step 4 treatment (p = 0.037). Vitamin D levels correlated with forced vital capacity (FVC), forced expiratory volume in the first second of expiration (FEV₁), and peak expiratory flow (r, 0.221-0.236; p ≤ 0.001). In addition, a positive relationship was found between Asthma Control Test and vitamin D (r = 0.229; p = 0.001). However, body mass index (BMI), asthma exacerbation, and hospitalization were inversely related to vitamin D (r, 0.198-0.233; p = 0.001). Multivariable regression analysis revealed that FVC (p = 0.002), FEV₁ (p = 0.033), and BMI (p = 0.037) were independent determinants associated with vitamin D. Conclusion: This study suggested a high prevalence of vitamin D deficiency in adults with asthma living in different geographic areas in Turkey. Vitamin D deficiency is associated with asthma severity, poor control, and lower lung function.

Safety of anti-inflammatory drugs in children with asthma

PURPOSE OF REVIEW

Inhaled corticosteroids (ICS) are widely used as the first-line treatment of asthma. When the disease is not controlled by standard doses of ICS, other anti-inflammatory drugs should be considered. The aim of this report is to review the main adverse events induced by anti-inflammatory drugs in children with asthma and discuss possible actions to prevent or mitigate these effects.

RECENT FINDINGS

Proper interpretation of ICS safety studies requires knowledge of the pharmaceutical properties and delivery device systems of the different ICS available. Genetic variants affecting susceptibility to corticosteroid-induced adrenal suppression were found in children and adults who use ICS to treat their asthma. There is evidence of the association between montelukast use and neuropsychiatric events.

SUMMARY

Benefits of ICS, properly prescribed and used, outweigh their potential adverse effects. There is substantial evidence that the combination of ICS with long-acting beta2 agonists is safe for asthmatic children. Awareness of the potential risks of neuropsychiatric events in children taking montelukast should inform the clinicians' prescribing practices. Omalizumab is generally well-tolerated, but the evidence on the safety of other biologic agents in children is scanty. The risk of systemic adverse events with anti-inflammatory drugs must be balanced against the risks of uncontrolled asthma and/or frequent oral steroid use.

Inhaled Corticosteroids and Endocrine Effects in Childhood

Asthma is the most common chronic inflammatory disease of children, and inhaled corticosteroids (ICSs) are the most effective and commonly used treatment of persistent asthma. ICSs currently approved for and commonly used by children with asthma include beclomethasone dipropionate, budesonide, fluticasone propionate, mometasone furoate, ciclesonide, and triamcinolone acetonide. This article reviews 4 areas critical to understanding potential adverse endocrine outcomes of ICSs and placing them in proper perspective: (1) influence of drug/delivery device properties on systemic steroid burden; (2) adrenal insufficiency during ICS treatment; (3) growth effects of ICS and asthma itself; and (4) bone mineral accretion during ICS therapy.

A Chinese Prescription Yu-Ping-Feng-San Administered in Remission Restores Bronchial Epithelial Barrier to Inhibit House Dust Mite-Induced Asthma Recurrence

Clinically, the treatments against asthma like β₂ agonist focus on controlling the symptoms rather than inhibiting recurrence radically. This study aims to evaluate the efficacy and mechanism of a potent Chinese prescription Yu-Ping-Feng-San (YPFS) against asthma recurrence. We here established an optimized house dust mite (HDM)-induced asthma recurrence mice model with typical asthmatic responses such as significantly augmented airway hyperresponsiveness (AHR), elevated serum IgE, pulmonary type 2 cytokines IL-5 and IL-13 levels, pathological changes including thickening bronchial wall, inflammatory infiltration of lung tissue, etc. Moreover, all typical asthmatic pathological features were prominently alleviated by YPFS applied during remission phase ahead of second elicitation, which was even more effective than three different types of medications dexamethasone, montelukast and salbutamol, which were commonly applied in clinical practice, administered during recurrence phase. Besides, we found that desmoglein 1 (DSG1) remained deficient when asthmatic responses regressed whereas tight junction (TJ) claudin 1 (CLDN1) or adherin junction (AJ) E-cadherin restored spontaneously. In vitro, DSG1 interference resulted in increased thymic stromal lymphopoietin (TSLP) secretion, and epithelial barrier compromise evidenced by significantly elevated transepithelial electrical resistance (TEER) and increased 4-kDa FITC-dextran influx. YPFS could downregulate TSLP production and restore HDM-induced DSG1 deficiency and barrier destruction, which was further reversed by shDSG1. Collectively, administration of YPFS in remission prominently alleviated HDM-induced asthma relapse by restoring DSG1 and decreasing TSLP overexpression, which might be the key factors contributing to chronic asthma relapse. Our data not only demonstrated the pivotal role of DSG1 in asthma pathogenesis, but also provided a novel and potent therapeutic strategy against chronic asthma.

Benefits and harm of systemic steroids for short- and long-term use in rhinitis and rhinosinusitis: an EAACI position paper

Because of the inflammatory mechanisms of most chronic upper airway diseases such as rhinitis and chronic rhinosinusitis, systemic steroids have been used for their treatment for decades. However, it has been very well documented that—potentially severe—side-effects can occur with the accumulation of systemic steroid courses over the years. A consensus document summarizing the benefits of systemic steroids for each upper airway disease type, as well as highlighting the potential harms of this treatment is currently lacking. Therefore, a panel of international experts in the field of Rhinology reviewed the available literature with the aim of providing recommendations for the use of systemic steroids in treating upper airway disease.

Effect of long term inhaled corticosteroid therapy on adrenal suppression, growth and bone health in children with asthma

BACKGROUND

Inhaled corticosteroids (ICS) are the most effective treatment for children with persistent asthma. However adverse effects of ICS on Hypothalamo Pituitary Adrenal (HPA) axis, growth and bone metabolism are a concern. Hence the primary objective of this study was to describe the effects of long term inhaled corticosteroid therapy (ICS) on adrenal function, growth and bone health in children with asthma in comparison to an age and sex matched group of children with asthma who were not on long term ICS. Describing the association between the dose of ICS and duration of therapy on the above parameters were secondary objectives.

METHOD

Seventy children with asthma on ICS and 70 controls were studied. Diagnosis of asthma in selected patients was reviewed according to the criteria laid down by GINA 2018 guidelines. The estimated adult heights were interpreted relative to their Mid Parental Height (MPH) range. Serum calcium, alkaline phosphatase and vitamin D levels were analyzed in both groups and cortisol value at 30 min following a low dose short synacthen test was obtained from the study group. The average daily dose of ICS (Beclamethasone) was categorized as low, medium and high (100-200, 200-400, > 400 μg /day) respectively according to published literature.

RESULTS

Heights of all children were within the MPH range. There was no statistically significant difference in the bone profiles and vitamin D levels between the two groups (Ca: p = 0.554, vitamin D: p = 0.187) but vitamin D levels were insufficient (< 50 nmol/l) in 34% of cases and 41% of controls. Suppressed cortisol levels were seen in 24%. Doses of ICS were low, medium and high in 56, 32 and 12% of children respectively. The association between adrenal suppression with longer duration of therapy (p < 0.01) and with increasing dose of ICS (p < 0.001) were statistically significant.

CONCLUSION

ICS had no impact on the growth and bone profiles but its dose and duration were significantly associated with adrenal suppression.

Asthma and Medicines - Long-Term Side-Effects, Monitoring and Dose Titration

Asthma is a major pediatric respiratory morbidity requiring long-term management. A thorough knowledge of long-term medication side-effects in children is, thus, essential for every physician dealing with childhood asthma. Establishing diagnosis and initiating treatment is just a beginning of the journey. Ongoing monitoring is an essential component of comprehensive asthma management programme. Monitoring includes not only assessment of asthma control but also checking for adherence to treatment, technique of inhaler device use, associated co-morbities, if any, and potential environmental exposure. Various tools - both subjective and objective - are available for assessment of asthma control. However, evidence for their optimum use in different settings and patient groups is lacking and monitoring has to be customized depending on available resources and individual patient characteristics. Patient education is an important component of long-term asthma therapy. The ultimate aim is to achieve optimum asthma control i.e., achieve and maintain control of clinical symptoms, decrease future risk to patients (risk of exacerbations, progressive loss of lung function and development of fixed airflow obstruction, adverse effects of medications) and enabling the child to lead a life without restrictions, at lowest possible dose of drugs. This article reviews the side-effects of medications used for long-term management of asthma and discusses current literature on asthma monitoring and dose titration in pediatric population to help the asthma therapist not only prescribe the drugs rationally but also help the family make right choices for treatment.

Budesonide and Calcitriol Synergistically Inhibit Airway Remodeling in Asthmatic Mice

Background and Objective

While calcitriol can inhibit airway remodeling in asthmatic mice, the mechanism remains unclear. The purpose of this study was to explore the mechanism of action of calcitriol on airway remodeling in asthma and its interaction with budesonide.

Methods

A mouse model of asthma was established by allergic sensitization and challenge with ovalbumin. The mice were treated with budesonide, calcitriol, or budesonide plus calcitriol. The expression of airway remodeling-related proteins, transforming growth factor β (TGFβ) signaling pathway-related proteins, the glucocorticoid receptor, and vitamin D receptor (VDR) was determined by immunohistochemical staining and Western blot analysis. Quantitative real-time PCR was used to determine the expression of microRNA-21 (miR-21) in the lung tissue of mice.

Results

Monotherapy with budesonide or calcitriol inhibited the high expression of collagen type I protein and upregulated the low expression of Smad7 in asthmatic mice. There was a synergistic interaction between budesonide and calcitriol in combined treatment. The expression of miR-21 in the combined treatment group was significantly lower than that in the calcitriol treatment group. VDR expression in the combined treatment group was significantly higher than that of the calcitriol treatment group.

Conclusion

Budesonide and calcitriol have a synergistic effect on airway remodeling in asthmatic mice.

Severe Asthma in Children

Severe asthma in children is associated with significant morbidity and is a highly heterogeneous disorder with multiple clinical phenotypes. Cluster analyses have been performed in several groups to explain some of the heterogeneity of pediatric severe asthma, which is reviewed in this article. The evaluation of a child with severe asthma includes a detailed diagnostic assessment and excluding other possible diagnoses and addressing poor control due to comorbidities, lack of adherence to asthma controller medications, poor technique, and other psychological and environmental factors. Children with severe asthma require significant resources including regular follow-up appointments with asthma education, written asthma action plan, and care by a multidisciplinary team. Management of pediatric severe asthma now includes emerging phenotypic-directed therapies; however, continued research is still needed to further study the long-term outcomes of pediatric severe asthma and its treatment.

Benefits and Risks of Long-Term Asthma Management in Children: Where Are We Heading?

International guidelines provide recommendations for a stepwise approach to the management of asthma in children 0-4 years old, 5-11 years old, and adolescents who are treated as adults. Therapy is aimed at two domains of control: current impairment and future risk. The long-term controller medications, inhaled corticosteroids (ICSs), ICSs in combination with long-acting β₂ agonists, leukotriene receptor antagonists, and immunomodulators, exhibit different efficacies for these domains. The risk:benefit ratios of the available medications need to be carefully assessed. This review briefly presents the benefits and the potential risks of available asthma medications in children to assist the practitioner in the optimal use of asthma medications. Specifically, the systemic activity of the ICSs and how to minimize their effects on growth and adrenal activity are reviewed as well as other potential adverse effects. Dosing strategies such as intermittent therapy are also assessed.

Dietary vitamin D3 deficiency exacerbates sinonasal inflammation and alters local 25(OH)D3 metabolism

RATIONALE

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have been shown to be vitamin D3 (VD3) deficient, which is associated with more severe disease and increased polyp size. To gain mechanistic insights into these observational studies, we examined the impact of VD3 deficiency on inflammation and VD3 metabolism in an Aspergillus fumigatus (Af) mouse model of chronic rhinosinusitis (Af-CRS).

METHODS

Balb/c mice were fed control or VD3 deficient diet for 4 weeks. Mice were then sensitized with intraperitoneal Af, and one week later given Af intranasally every three days for four weeks while being maintained on control or VD3 deficient diet. Airway function, sinonasal immune cell infiltrate and sinonasal VD3 metabolism profiles were then examined.

RESULTS

Mice with VD3 deficiency had increased Penh and sRaw values as compared to controls as well as exacerbated changes in sRaw when coupled with Af-CRS. As compared to controls, VD3 deficient and Af-CRS mice had reduced sinonasal 1α-hydroxylase and the active VD3 metabolite, 1,25(OH)2D3. Differential analysis of nasal lavage samples showed that VD3 deficiency alone and in combination with Af-CRS profoundly upregulated eosinophil, neutrophil and lymphocyte numbers. VD3 deficiency exacerbated increases in monocyte-derived dendritic cell (DC) associated with Af-CRS. Conversely, T-regulatory cells were decreased in both Af-CRS mice and VD3 deficient mice, though coupling VD3 deficiency with Af-CRS did not exacerbate CD4 or T-regulatory cells numbers. Lastly, VD3 deficiency had a modifying or exacerbating impact on nasal lavage levels of IFN-γ, IL-6, IL-10 and TNF-α, but had no impact on IL-17A.

CONCLUSIONS

VD3 deficiency causes changes in sinonasal immunity, which in many ways mirrors the changes observed in Af-CRS mice, while selectively exacerbating inflammation. Furthermore, both VD3 deficiency and Af-CRS were associated with altered sinonasal VD3 metabolism causing reductions in local levels of the active VD3 metabolite, 1,25(OH)2D3, even with adequate circulating levels.

Bone Mineral Density to Assess Pediatric Bone Health in Drug Development

BACKGROUND

Pediatric bone health is an important part of the safety assessment of inhaled corticosteroids and certain other drugs. Current regulatory guidance for assessment of bone health for intranasal and inhaled corticosteroid drugs is a single 1-year study of linear growth.

OBJECTIVE

The objective of this study was to assess whether a significant change in bone mineral density (BMD) could be observed during a 12-month period in pediatric patients being treated for asthma with an inhaled corticosteroid using a previously conducted study.

METHODS

The publicly available information from the Childhood Asthma Management Program (CAMP) study was used to assess whether a statistically significant difference in BMD could be detected over a 1-year period. Patients who were at Tanner stage ≥2 were excluded from analysis as is stated in the present FDA Guidance on growth studies with inhaled corticosteroids, and children with any use of oral corticosteroids were also excluded. A comparison in BMD change over time (bone mineral accretion [BMA]) between baseline and 12 months of follow-up was made for the placebo and inhaled budesonide groups using multiple regression analysis to account for age, race, and gender as covariates.

RESULTS

From the original 1041 patients in the CAMP study, 74 patients met the criteria for evaluation, with 42 patients receiving budesonide and 32 placebo patients. Children randomized to budesonide had a lower mean BMA than those receiving placebo (0.021 ± 0.023 [SD] g/cm²/y vs 0.036 ± 0.025 [SD] g/cm²/y).

CONCLUSION

In a select pediatric patient population, a significant change in BMA can be observed over 12 months on an inhaled corticosteroid. Based on this post hoc analysis, measurement of BMA as an assessment of pediatric bone health may be considered for certain drugs, especially when there is a potential signal of bone toxicity from animal or human data. The clinical relevance of this finding is presently unknown, and more data on the relationship between changes in BMA and clinical pediatric bone health outcomes are needed.

Quantitative Ultrasound Measurement at the Hand Phalanges Does Not Reveal Skeletal Disturbances in Children With Bronchial Asthma: A Longitudinal Observation

OBJECTIVES

To assess the skeletal status in asthmatic children treated with inhaled corticosteroids in a longitudinal observation by quantitative ultrasound (US) measurement at the hand phalanges.

METHODS

Thirty-four children were studied prospectively. Quantitative US measurements were performed at baseline and after a mean ± SD of 2.35 ± 0.20 years. The obtained results were compared to age-, sex-, and body size-matched control participants selected from a database of previously examined healthy children. Individual changes in the amplitude-dependent speed of sound (Ad-SoS) during the follow-up period were also analyzed.

RESULTS

The mean age of the asthmatic children was 10.6 ± 2.5 years. The mean Ad-SoS in the asthmatic children at baseline was 1940.5 ± 49.6 m/s, and the mean Z score was -0.26 ± 0.80. Corresponding values at the follow-up examination were 1976.2 ± 63.6 m/s and -0.18 ± 1.16. The results did not differ significantly in comparison to the healthy controls. The analysis of individual changes in Ad-SoS revealed that 18 participants had a significant increase in this parameter (ie, exceeding the least significant change threshold), and 16 did not have a significant change in their values. No one had a significant decrease in Ad-SoS.

CONCLUSIONS

Quantitative US at the hand phalanges applied as a diagnostic tool revealed no essential differences in the pattern of skeletal development between asthmatic children treated with inhaled glucocorticosteroids and healthy controls.

A genetic factor associated with low final bone mineral density in children after a long-term glucocorticoids treatment

Treatment with glucocorticoids is associated with lower bone mineral density (BMD). We performed a genome-wide association study to analyze interactive effects between genotypes and cumulative dose of prednisone (PD) over 4.3 years of follow-up period on the final BMD Z-scores in 461 white children from the Childhood Asthma Management Program. No variants met the conventional criteria for genome-wide significance, and thus we looked for evidence of replication. The top 100-ranked single-nucleotide polymorphisms (SNPs) were then carried forward replication in 59 children with acute lymphoblastic leukemia (ALL) exposed to large fixed doses of PD as part of their chemotherapeutic regimen. Among them, rs6461639 (interaction P=1.88 × 10-5 in the CAMP population) showed a significant association with the final BMD Z-scores in the ALL population (P=0.016). The association of the ALL population was only present after correction for the anti-metabolite treatment arm (high vs low dose). We have identified a novel SNP, rs6461639, showing a significant effect on the final BMD Z-scores in two independent pediatric populations after long-term high-dose PD treatment.

Dietary 2-oxoglutarate prevents bone loss caused by neonatal treatment with maximal dexamethasone dose

Synthetic glucocorticoids (GCs) are widely used in the variety of dosages for treatment of premature infants with chronic lung disease, respiratory distress syndrome, allergies, asthma, and other inflammatory and autoimmune conditions. Yet, adverse effects such as glucocorticoid-induced osteoporosis and growth retardation are recognized. Conversely, 2-oxoglutarate (2-Ox), a precursor of glutamine, glutamate, and collagen amino acids, exerts protective effects on bone development. Our aim was to elucidate the effect of dietary administered 2-Ox on bone loss caused by neonatal treatment with clinically relevant maximal therapeutic dexamethasone (Dex) dose. Long bones of neonatal female piglets receiving Dex, Dex+2-Ox, or untreated were examined through measurements of mechanical properties, density, mineralization, geometry, histomorphometry, and histology. Selected hormones, bone turnover, and growth markers were also analyzed. Neonatal administration of clinically relevant maximal dose of Dex alone led to over 30% decrease in bone mass and the ultimate strength ( P < 0.001 for all). The length (13 and 7% for femur and humerus, respectively) and other geometrical parameters (13-45%) decreased compared to the control ( P < 0.001 for all). Dex impaired bone growth and caused hormonal imbalance. Dietary 2-Ox prevented Dex influence and vast majority of assessed bone parameters were restored almost to the control level. Piglets receiving 2-Ox had heavier, denser, and stronger bones; higher levels of growth hormone and osteocalcin concentration; and preserved microarchitecture of trabecular bone compared to the Dex group. 2-Ox administered postnatally had a potential to maintain bone structure of animals simultaneously treated with maximal therapeutic doses of Dex, which, in our opinion, may open up a new opportunity in developing combined treatment for children treated with GCs. Impact statement The present study has showed, for the first time, that dietary 2-oxoglutarate (2-Ox) administered postnatally has a potential to improve/maintain bone structure of animals simultaneously treated with maximal therapeutic doses of dexamethasone (Dex). It may open the new direction in searching and developing combined treatment for children treated with glucocorticoids (GCs) since growing group of children is exposed to synthetic GCs and adverse effects such as glucocorticoid-induced osteoporosis and growth retardation are recognized. Currently proposed combined therapies have numerous side effects. Thus, this study proposed a new direction in combined therapies utilizing dietary supplementation with glutamine derivative. Impairment caused by Dex in presented long bones animal model was prevented by dietary supplementation with 2-Ox and vast majority of assessed bone parameters were restored almost to the control level. These results support previous thesis on the regulatory mechanism of nutrient utilization regulated by glutamine derivatives and enrich the nutritional science.

Glucocorticoid-induced osteoporosis: pathophysiological role of GH/IGF-I and PTH/VITAMIN D axes, treatment options and guidelines

Glucocorticoid-induced osteoporosis is the most frequent form of secondary osteoporosis caused by chronic exposure to glucocorticoid excess. Pathogenesis of glucocorticoid-induced osteoporosis is multifactorial including direct effects of glucocorticoids on bone cells and indirect effects of glucocorticoids on several neuroendocrine and metabolic pathways. Fragility fractures occur early in glucocorticoid-induced osteoporosis and anti-osteoporotic drugs along with calcium and vitamin D should be started soon after exposure to glucocorticoid excess. This paper summarizes some of the main topics discussed during the 9th Glucocorticoid-Induced Osteoporosis Meeting (Rome, April 2016) with a specific focus on the role of growth hormone/insulin-like growth factor-1 and parathyroid hormone/vitamin D axes in the pathogenesis of glucocorticoid-induced osteoporosis and the controversial aspects concerning therapeutic approach to skeletal fragility in this clinical setting.

Adequate Vitamin D Intake but Low Serum Levels in Pediatric Asthma Patients: A Pilot Study, Alberta Children's Hospital

Background. We assessed vitamin D intakes and serum 25(OH) vitamin D levels in pediatric asthma patients on moderate-to-high dose inhaled steroids and compared them to published findings of healthy children in our city. Methods. Parents and/or patients were interviewed to estimate the children's vitamin D intakes from foods and supplements (using an adapted validated food frequency questionnaire) and asthma duration and management. Vitamin D status: serum 25-hyroxy vitamin D (25(OH)D) was obtained from the medical records. Results. Vitamin D intakes from food and supplements of the asthma patients (n = 20, 742 ± 185 IU/day) were significantly higher compared to healthy Canadian children (n = 1442, 229 ± 121 IU/day). Despite higher vitamin D intakes, the children had nonsignificantly lower serum 25(OH) vitamin D levels compared to the comparison group. Serum 25(OH)D levels increased by 3.6 nmol/L with each 100 IU of vitamin D intake (95% Confidence interval = 2.0-4.0, R² = 0.931, and p = 0.001). Conclusion. Since adequate vitamin D status in asthma patients is necessary to support bone mineral accretion, it is important to achieve adequate vitamin D status by checking serum 25(OH)D status and supplement accordingly.

Genetic risk factors for decreased bone mineral accretion in children with asthma receiving multiple oral corticosteroid bursts

BACKGROUND

Long-term intermittent oral corticosteroid (OCS) use in children with asthma leads to significant decreases in bone mineral accretion (BMA).

OBJECTIVE

We aimed to identify genetic factors influencing OCS dose effects on BMA in children with asthma.

METHODS

We first performed a gene-by-OCS interaction genome-wide association study (GWAS) of BMA in 489 white participants in the Childhood Asthma Management Program trial who took short-term oral prednisone bursts when they experienced acute asthma exacerbations. We selected the top-ranked 2000 single nucleotide polymorphisms (SNPs) in the GWAS and determined whether these SNPs also had cis-regulatory effects on dexamethasone-induced gene expression in osteoblasts.

RESULTS

We identified 2 SNPs (rs9896933 and rs2074439) associated with decreased BMA and related to the tubulin γ pathway. The rs9896933 variant met the criteria for genome-wide significance (P = 3.15 × 10(-8) in the GWAS) and is located on the intron of tubulin folding cofactor D (TBCD) gene. The rs2074439 variant (P = 2.74 × 10(-4) in the GWAS) showed strong cis-regulatory effects on dexamethasone-induced tubulin γ gene expression in osteoblasts (P = 8.64 × 10(-4)). Interestingly, we found that BMA worsened with increasing prednisone dose as the number of mutant alleles of the 2 SNPs increased.

CONCLUSIONS

We have identified 2 novel tubulin γ pathway SNPs, rs9896933 and rs2074439, showing independent interactive effects with cumulative corticosteroid dose on BMA in children with asthma receiving multiple OCS bursts.

Vitamin D and Asthma: Association, Causality, or Intervention?

Many observational studies have investigated the potential association between vitamin D and asthma. However, it is difficult to find a temporal causal relationship in cross-sectional or observational studies. This review presents recent clinical trials and the evidence of association between vitamin D and asthma in different patient populations and asthma status. Well-designed clinical trials are warranted in order to define the optimal level of vitamin D, as well as dosing and duration of vitamin D supplementation, in pediatric patients.

Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms

Vitamin D deficiency (VDD) is highly prevalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

25-Hydroxyvitamin D3-deficiency enhances oxidative stress and corticosteroid resistance in severe asthma exacerbation

Oxidative stress plays a significant role in exacerbation of asthma. The role of vitamin D in oxidative stress and asthma exacerbation remains unclear. We aimed to determine the relationship between vitamin D status and oxidative stress in asthma exacerbation. Severe asthma exacerbation patients with 25-hydroxyvitamin D3-deficiency (V-D deficiency) or 25-hydroxyvitamin D-sufficiency (V-D sufficiency) were enrolled. Severe asthma exacerbation with V-D-deficiency showed lower forced expiratory volume in one second (FEV1) compared to that with V-D-sufficiency. V-D-deficiency intensified ROS release and DNA damage and increased TNF-α, OGG1 and NFκB expression and NFκB phosphorylation in severe asthma exacerbation. Supplemental vitamin D3 significantly increased the rates of FEV1 change and decreased ROS and DNA damage in V-D-deficiency. Vitamin D3 inhibited LPS-induced ROS and DNA damage and were associated with a decline in TNF-α and NFκB in epithelial cells. H₂O₂ reduces nuclear translocation of glucocorticoid receptors in airway epithelial cell lines. V-D pretreatment enhanced the dexamethasone-induced nuclear translocation of glucocorticoid receptors in airway epithelial cell lines and monocytes from 25-hydroxyvitamin D3-deficiency asthma patients. These findings indicate that V-D deficiency aggravates oxidative stress and DNA damage, suggesting a possible mechanism for corticosteroid resistance in severe asthma exacerbation.

Inhaled corticosteroids in children: effects on bone mineral density and growth

Potent, topically active corticosteroids with minimum systemic activity have fewer adverse effects than do systemic corticosteroids, and can control both asthma and allergic rhinitis when given in recommended doses. However, study findings show that children with asthma receiving budesonide and beclometasone dipropionate have decreased linear growth, and that children who receive long-term inhaled corticosteroid therapy for asthma have height deficits 1-2 years after treatment initiation that persist into adulthood. The effects of inhaled corticosteroids on growth seem to be dependent on both dose and duration; the degree of systemic effects is dependent on pharmacokinetic properties (ie, absorption, distribution, and elimination), whereas the effective dose delivered is dependent on the delivery system and potency of the molecule. The effects of corticosteroids on bone mineral density in children seem to be more amenable to intervention; long-term therapy with inhaled corticosteroid therapy is safer than frequent bursts of oral corticosteroids on bone mineral accretion in this regard. Importantly, adequate nutrition (particularly sufficient intake of calcium and vitamin D) should prevent or blunt the effects of corticosteroids on bone mineral density. The potential adverse effects of inhaled corticosteroids need to be weighed against the large and well established benefit of these drugs to control persistent asthma. To minimise any adverse effects, treatment with inhaled corticosteroids should always aim to reach the lowest effective dose that gives the patient good asthma control.

Plasma exchange induces vitamin D deficiency

BACKGROUND

Plasma exchange is used in the treatment of diseases mediated by pathogenic circulating proteins, or for transplant desensitization. Its non-targeted nature results in the depletion of physiologically important molecules, and it is often complicated by hypocalcaemia.

AIM

To determine the effects of plasma exchange on vitamin D binding protein (DBP) and associated vitamin D metabolites.

DESIGN

Single-centre prospective cohort study of 11 patients.

METHODS

DBP and vitamin D metabolites were measured before and immediately after five plasma exchanges, and 7 and 28 days after discontinuation of plasma exchange.

RESULTS

Plasma exchange reduced plasma DBP concentration from 196.9 ± 53.2 to 98.5 ± 34 μg/ml (P = 0.0001), 1,25-dihydroxyvitamin D from 103 ± 52 to 42 ± 4 pmol/l (P = 0.003) and 25-hydroxyvitamin D from 49.7 ± 29 to 22 ± 9.4 nmol/l (P = 0.0017), through their removal in effluent. After 7 days, DBP and 1,25-dihydroxyvitamin D were not significantly different from baseline, but 25-hydroxyvitamin D remained significantly lower after 7 days (26.4 ± 9.8 nmol/l, P = 0.02) and 28 days (30.8 ± 15.5 nmol/l, P = 0.048). Corrected calcium decreased from 2.23 ± 0.11 to 1.98 ± 0.08 mmol/l (P = 0.0007) immediately after five treatments. Plasma calcium was significantly associated with 1,25-dihydroxyvitamin D (r(2) = 0.79, P < 0.0001).

CONCLUSION

Plasma exchange induced an acute reversible decrease in plasma 1,25-dihydroxyvitamin D, DBP, calcium and a sustained decrease in plasma 25-hydroxyvitamin D.

Genetic variation in Ameloblastin is associated with caries in asthmatic children

AIM

Evidence suggests caries experience is higher in children with asthma. This study compared caries experience in asthmatic and non-asthmatic children and defined whether variation in the distribution of caries experience differed between the two groups and was dependent on the presence of genetic variation in enamel formation genes.

METHODS

Children with asthma were recruited at the Istanbul University, Faculty of Medicine, Department of Paediatrics, Division of Paediatric Allergy and Pulmonary Diseases, and non-affected children were recruited at the Istanbul University, Faculty of Dentistry, Department of Paedodontics. Cases (N = 100) were defined as children between the ages of 6 and 12 years with asthma and controls (N = 100) as children without asthma. Cases and controls were matched by sex and age. All study subjects received a complete dental exam, provided demographic and other caries and asthma risk factors data, and a saliva sample for DNA extraction. Caries experience was defined based on DMFT/dmft and DMFS/dmfs scores. Genotypes of 11 SNPs were selected in intronic regions of enamel development genes. PCR with TaqMan chemistry was used for genotyping all selected markers. Association between caries experience (caries-free versus caries affected) depending on asthma status and SNPs was tested with PLINK by logistic regression, adjusting by risk, and other preventive measures. p values below 0.0045 (0.05/11) were considered statistically significant.

RESULTS

Logistic regression analysis showed an association between AMBN rs4694075 and caries experience (p = 2.525e-007).

CONCLUSIONS

This study provides, for the first time, evidence that ameloblastin is associated with caries in asthmatic children.

Should vitamin D supplementation be a regular part of asthma care?

Vitamin D (vitD3) deficiency occurs frequently and has profound effects on health, especially asthma. This article examines how current knowledge of vitD3 actions and the worldwide distribution of vitD3 deficiency influences everyday clinical allergy practice. Within the limits of current knowledge, the article concisely explains the molecular nature of vitD3 actions, reviews key vitD3 research as it applies to clinical care, answers questions about the potential clinical impact of low vitD3 levels, and discusses use and safety of vitD3 supplements.

Vitamin D in asthma and future perspectives

Humans have the ability to synthesize vitamin D during the action of ultraviolet (UV) radiation upon the skin. Apart from the regulation of calcium and phosphate metabolism, another critical role for vitamin D in immunity and respiratory health has been revealed, since vitamin D receptors have also been found in other body cells. The term "vitamin D insufficiency" has been used to describe low levels of serum 25-hydroxyvitamin D that may be associated with a wide range of pulmonary diseases, including viral and bacterial respiratory infection, asthma, chronic obstructive pulmonary disease, and cancer. This review focuses on the controversial relationship between vitamin D and asthma. Also, it has been found that different gene polymorphisms of the vitamin D receptor have variable associations with asthma. Other studies investigated the vitamin D receptor signaling pathway in vitro or in experimental animal models and showed either a beneficial or a negative effect of vitamin D in asthma. Furthermore, a range of epidemiological studies has also suggested that vitamin D insufficiency is associated with low lung function. In the future, clinical trials in different asthmatic groups, such as infants, children of school age, and ethnic minorities are needed to establish the role of vitamin D supplementation to prevent and/or treat asthma.

Reversible control by vitamin D of granulocytes and bacteria in the lungs of mice: an ovalbumin-induced model of allergic airway disease

Vitamin D may be essential for restricting the development and severity of allergic diseases and asthma, but a direct causal link between vitamin D deficiency and asthma has yet to be established. We have developed a 'low dose' model of allergic airway disease induced by intraperitoneal injection with ovalbumin (1 µg) and aluminium hydroxide (0.2 mg) in which characteristics of atopic asthma are recapitulated, including airway hyperresponsiveness, antigen-specific immunoglobulin type-E and lung inflammation. We assessed the effects of vitamin D deficiency throughout life (from conception until adulthood) on the severity of ovalbumin-induced allergic airway disease in vitamin D-replete and -deficient BALB/c mice using this model. Vitamin D had protective effects such that deficiency significantly enhanced eosinophil and neutrophil numbers in the bronchoalveolar lavage fluid of male but not female mice. Vitamin D also suppressed the proliferation and T helper cell type-2 cytokine-secreting capacity of airway-draining lymph node cells from both male and female mice. Supplementation of initially vitamin D-deficient mice with vitamin D for four weeks returned serum 25-hydroxyvitamin D to levels observed in initially vitamin D-replete mice, and also suppressed eosinophil and neutrophil numbers in the bronchoalveolar lavage fluid of male mice. Using generic 16 S rRNA primers, increased bacterial levels were detected in the lungs of initially vitamin D-deficient male mice, which were also reduced by vitamin D supplementation. These results indicate that vitamin D controls granulocyte levels in the bronchoalveolar lavage fluid in an allergen-sensitive manner, and may contribute towards the severity of asthma in a gender-specific fashion through regulation of respiratory bacteria.

Corticosteroid therapy in critically ill pediatric asthmatic patients

OBJECTIVES

IV corticosteroids are routinely prescribed to treat critically ill children with asthma. However, no specific dosing recommendations have been made for children admitted to the PICU. We aim to determine current asthma corticosteroid dosing preferences in PICUs within North America.

DESIGN

Cross-sectional, self-administered survey.

SETTING

North American PICUs.

SUBJECTS

Pediatric intensivists working in the United States and Canada.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 104 intensivists completed the survey. Of these, 70% worked in the United States, 67% attended in PICUs with at most 20 beds, and 79% had more than 10 years of PICU experience. The majority of asthmatics were admitted to PICUs based on clinical asthma examination/score or because the patient was receiving continuous albuterol. IV methylprednisolone is prescribed by a large majority of intensivists (96%). Of those who prescribe methylprednisolone, 66% use a starting dose of 4 mg/kg/d, whereas 31% use a starting dose of 2 mg/kg/d, and only 3% use 1 mg/kg/d. The large majority of respondents (85%) use "clinical experience" as their rationale for their preferred dosage. In multivariate logistic regression analysis, only knowledge of the National Heart, Lung, and Blood Institute guidelines was an independent predictor of prescribing an initial corticosteroid dose of 4 mg/kg/d (odds ratio, 3.69 [95% CI, 1.26-10.80]; p = 0.017). Country of practice, years of experience, and PICU size were not associated with corticosteroid dosing preference.

CONCLUSIONS

Most intensivists administer methylprednisolone to critically ill asthmatics at doses 2 to 4 times higher than recommended by the National Heart, Lung, and Blood Institute guidelines for hospitalized asthmatic children. The rationale for these decisions is likely multifactorial, but in the absence of evidence-based data, most of them cite clinical experience as their deciding factor. Future research is needed to determine the most appropriate corticosteroid dosage in this critically ill patient population.

Advances in pediatric asthma in 2012: moving toward asthma prevention

Last year's "Advances in pediatric asthma: moving forward" concluded the following: "Now is also the time to utilize information recorded in electronic medical records to develop innovative disease management plans that will track asthma over time and enable timely decisions on interventions in order to maintain control that can lead to disease remission and prevention." This year's summary will focus on recent advances in pediatric asthma on modifying disease activity, preventing asthma exacerbations, managing severe asthma, and risk factors for predicting and managing early asthma, as indicated in Journal of Allergy and Clinical Immunology publications in 2012. Recent reports continue to shed light on methods to improve asthma management through steps to assess disease activity, tools to standardize outcome measures in asthma, genetic markers that predict risk for asthma and appropriate treatment, and interventions that alter the early presentation of asthma to prevent progression. We are well on our way to creating a pathway around wellness in asthma care and also to use new tools to predict the risk for asthma and take steps to not only prevent asthma exacerbations but also to prevent the early manifestations of the disease and thus prevent its evolution to severe asthma.

The Childhood Asthma Management Program (CAMP): Contributions to the Understanding of Therapy and the Natural History of Childhood Asthma

The Childhood Asthma Management Program (CAMP) has been in continuous existence for almost two decades, which makes it the largest randomized, placebo-controlled clinical trial with extended follow-up for children with mild to moderate asthma. As such, its cumulative data from baseline, active treatment, and post-treatment have proved to be an invaluable resource for not only assessing the efficacy and safety of long-term inhaled corticosteroid therapy in childhood, but for discovery of many other aspects of childhood asthma, including genetics and biomarkers.