Vitamin D and Vascular Health in Children
Vitamin D and Vascular Function in Obese Children
研究概览
详细说明
Our primary objective is to determine, in obese and overweight children aged 10 to 18 years with vitamin D deficiency (defined as serum 25-hydroxyvitamin D <20 ng/mL), the efficacy of enhanced vitamin D3 supplementation in improving vascular endothelial function, arterial stiffness, insulin sensitivity, and metabolic syndrome risk status; and to assess whether these effects are dose-dependent. As a secondary objective, we will examine the vitamin D supplementation-induced effect on adipokines and inflammatory markers relevant to CVD risk. In a double-masked, controlled trial, we will randomize 252 eligible children to receive either 600 IU (conventional supplementation), or 1000 IU or 2000 IU (enhanced supplementation) of vitamin D3 daily for 6 months.
In terms of reporting of results, the following pre-specified outcomes are included in the primary manuscript (PubMed PMID:31950134 -- see Reference section for citation details)
- Waist Circumference
- Serum High Density Lipoprotein (HDL) Cholesterol
- Serum Triglycerides
- Inflammatory markers (Plasma TNF-alpha, high-sensitivity C-reactive protein, and IL-6)
- Adiopkines (Plasma Leptin and Adiponectin)
Plasma nitric oxide metabolites were not measured.
研究类型
注册 (实际的)
阶段
- 不适用
联系人和位置
学习地点
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Pennsylvania
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Pittsburgh、Pennsylvania、美国、15213
- Primary Care Center, Children's Hospital of Pittsburgh of UPMC
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参与标准
资格标准
适合学习的年龄
接受健康志愿者
有资格学习的性别
描述
Inclusion Criteria:
- Eligible subjects will be 10 to 18 years of age;
- obese or overweight (BMI ≥85th %tile);
- otherwise healthy, and
- have a serum 25(OH)D concentration <20 ng/mL
Children taking multivitamins should be able to hold off their multivitamins during the course of the study.
Exclusion Criteria:
Children will be excluded if they
- (a) have hepatic or renal disease, metabolic rickets, malabsorptive disorders, primary hyperparathyroidism, hyperthyroidism, or other chronic disorders that could affect vitamin D metabolism;
- (b) are receiving treatment with anticonvulsants, systemic glucocorticoids, pharmacologic doses of vitamin D (≥1000 IU of vitamin D2 or D3 daily), antihypertensives, vasoactive drugs, antilipidemics, metformin, antipsychotics, or other oral insulin regulators;
- (c) have cholelithiasis or urolithiasis;
- (d) have type 1 or type 2 diabetes; or
- (e) have a condition or underlying abnormality that could compromise the safety of the subject.
Post-menarchial girls with a positive pregnancy test at randomization, or subjects found during the screening phase to have hypercalcemia (serum calcium >10.8 mg/dL) or significant fasting hyperglycemia (fasting blood glucose ≥ 125 mg/dL) will also be excluded.
学习计划
研究是如何设计的？
设计细节
- 主要用途：治疗
- 分配：随机化
- 介入模型：并行分配
- 屏蔽：四人间
武器和干预
参与者组/臂 |
干预/治疗 |
|---|---|
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有源比较器：Vitamin D3 2000 IU
Vitamin D3 2000 IU tablet once daily by mouth for 6 months
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Tablet form
其他名称：
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有源比较器：Vitamin D3 1000 IU
Vitamin D3 1000 IU tablet by mouth once daily for 6 months
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Tablet form
其他名称：
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安慰剂比较：Vitamin D3 600 IU
Vitamin D3 600 IU tablet by mouth once daily for 6 months
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Tablet form
其他名称：
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研究衡量的是什么？
主要结果指标
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
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Flow-mediated Dilation (FMD) Percentage
大体时间：6 months
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Brachial artery flow-mediated dilation percentage is a measure of endothelial function.
FMD percentage calculation is based on baseline brachial artery diameter(brachialADbase) and change in brachial artery diameter (brachialADchange) during post-occlusive reactive hyperemia.
FMD% was determined using the formula (brachialADchange/brachialADbase) x 100.
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6 months
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次要结果测量
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
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Pulse-wave Velocity (PWV)
大体时间：6 months
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PWV is a measure of arterial stiffness.
Higher values of PWV indicate greater degree of arterial stiffness.
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6 months
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Augmentation Index at Heart Rate of 75 Beats/Min (AIx-75)
大体时间：6 months
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AIx-75 is a measure of arterial stiffness. AIx was measured through radial arterial tonometry using SphygmoCor. Radial pulse waveform are analyzed through an automatic software function to determine aortic pulse waveform and aortic or central systolic (cSBP) and diastolic blood pressure (cDBP), and these measurements are further analyzed automatically to calculate AIx. AIx is a composite measure of the magnitude of wave reflection and arterial stiffness in all conduit arteries which affect the timing of the wave reflection. AIx = P2-P1/cSBP-cDBP, where P1 is the height of the incident pressure wave form during systole, P2 is the height of the reflected wave added to the incident wave, cSBP is the aortic systolic BP, and cDBP is the aortic diastolic BP. AIx adjusted to heart rate of 75 beats/min (AIx-75) is a validated index of arterial stiffness, with higher values indicating higher degree of arterial stiffness. |
6 months
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Central Systolic Blood Pressure
大体时间：6 months
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a measure of cardiometabolic health
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6 months
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Central Diastolic Blood Pressure
大体时间：6 months
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a measure of cardiometabolic health
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6 months
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Systemic Systolic Blood Pressure
大体时间：6 months
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a measure of cardiometabolic health
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6 months
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Systemic Diastolic Blood Pressure
大体时间：6 months
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a measure of cardiometabolic health
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6 months
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Fasting Blood Glucose
大体时间：6 months
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a measure of cardiometabolic health
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6 months
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1/Fasting Insulin Ratio
大体时间：6 months
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1/fasting insulin ratio is a measure of insulin sensitivity.
Increases in 1/fasting insulin ratio indicate improvements in insulin sensitivity.
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6 months
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其他结果措施
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
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Body Mass Index (BMI)
大体时间：6 months
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a surrogate measure of adiposity
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6 months
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合作者和调查者
调查人员
- 首席研究员：Kumaravel Rajakumar, MD, MS、University of Pittsburgh, Children's Hospital of Pittsburgh of UPMC
出版物和有用的链接
研究记录日期
研究主要日期
学习开始 (实际的)
初级完成 (实际的)
研究完成 (实际的)
研究注册日期
首次提交
首先提交符合 QC 标准的
首次发布 (估计)
研究记录更新
最后更新发布 (实际的)
上次提交的符合 QC 标准的更新
最后验证
更多信息
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