Vitamin D to Prevent Severe Asthma Exacerbations in High-Risk Children - CCC

 描述（由申请人提供）：我们小组和其他人的观察性研究结果表明，维生素D不足（一种常见疾病）与学龄儿童严重哮喘急性发作的风险增加有关。我们假设，维生素D补充剂可降低6 - 14岁患有维生素D不足（血清25（OH）D <30 ng/ml）且正在接受吸入性皮质类固醇（ICS）治疗轻度至中度持续性哮喘的高危（由于前一年发生过哮喘发作而定义）儿童重度哮喘发作的发生率。我们进一步假设，这种保护作用是由于这些儿童中导致严重哮喘急性发作和/或对ICS反应增强的病毒感染发生率降低所致。我们将在一项随机、双盲、安慰剂对照的临床试验中检验这一假设，主要和次要具体目的如下：主要具体目的1）确定补充维生素D3（4，000 IU/天）在预防患有维生素D不足和因轻度至中度持续性哮喘而接受ICS治疗的高危学龄儿童重度哮喘急性发作方面是否上级安慰剂。次要特定目的在接受ICS治疗哮喘的维生素D不足的高危学龄儿童中，确定维生素D3补充剂在以下方面是否上级安慰剂：1）预防病毒感染导致的重度哮喘急性发作2）在试验结束时降低ICS的每日剂量以及ICS的平均累积剂量

 DESCRIPTION (provided by applicant): Findings from observational studies by our group and others suggest that vitamin D insufficiency (a common condition) is associated with an increased risk of severe asthma exacerbations in school-aged children. We hypothesize that vitamin D supplementation reduces the incidence of severe asthma exacerbations in high-risk (so defined due to an exacerbation in the previous year) children aged 6 to 14 years who have vitamin D insufficiency (a serum 25(OH) D <30 ng/ml) and who are being treated with inhaled corticosteroids (ICS) for mild to moderate persistent asthma. We further hypothesize that this protective effect results from a reduced incidence of viral infections that lead to severe asthma exacerbations and/or enhanced response to ICS in these children. We will test this hypothesis in a randomized double-masked placebo-controlled clinical trial with the following primary and secondary Specific Aims: Primary Specific Aim 1) To determine whether vitamin D3 supplementation (4,000 IU/day) is superior to placebo in preventing severe asthma exacerbations in high-risk school-aged children who have vitamin D insufficiency and who are on ICS for mild to moderate persistent asthma. Secondary Specific Aims In high-risk school-aged children with vitamin D insufficiency who are on ICS for asthma, to determine whether vitamin D3 supplementation is superior to placebo in: 1) Preventing severe asthma exacerbations resulting from viral infections 2) Reducing the daily dose of ICS as well as the average cumulative dose of ICS, at the end of the trial