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Effect of Vitamin D Supplementation on Endothelial Function in Obese Adolescents

2016年3月30日 更新者：Seema Kumar、Mayo Clinic
Vitamin D deficiency has been linked to endothelial dysfunction in adults. Obese adolescents have a high prevalence of Vitamin D deficiency as well as evidence of endothelial dysfunction. Our hypothesis is that supplementation of Vitamin D deficient adolescents with Vitamin D would lead to improvement in endothelial dysfunction.

研究概览

地位

完全的

条件

干预/治疗

详细说明

Subjects had a brief screening visit with one of the study team members. Past medical history, current medications and a brief dietary history was taken. The dietary history was taken to assess calcium intake in a day and was obtained via the validated Short Calcium questionnaire. Blood pressure, heart rate as well as height,weight, waist and hip circumference measurement was obtained by study staff. In addition, a brief physical examination to determine Tanner stage was also completed. This involved examination of both breasts and genitalia for adolescent female and only genitalia in males. A physical activity questionnaire (IPAQ) was also administered by the study staff at this visit. A blood draw of 5 ml to measure plasma 25(OH) D, calcium, phosphorus was obtained as part of the screening visit. For girls who had started menstruating, a urine pregnancy test was also obtained.

After the screening visit eligible subjects had baseline biochemical tests and an endothelial function assessment. Study participants received a pill container with six total pills of vitamin cholecalciferol (D3) (1 pill = 50,000 IU), with directions to take two pills once a month (100,000 IU) at the same time for a period of 3 months. Compliance was assessed at the 3 month visit by counting the number of pills remaining in the container.

At 1 month, the subjects had tests for serum calcium and 25 hydroxy vitamin D levels. A urine test for random calcium to creatinine ratio was also obtained.

At 2 months, the serum calcium, 25 hydroxy vitamin D levels, and calcium to creatinine ratio tests were repeated.

At the end of 3 months, biochemical tests and an endothelial function assessment were repeated. Medical history, questionnaires, and the physical exam were also repeated.

研究类型

介入性

注册 (实际的)

19

阶段

  • 阶段1

联系人和位置

本节提供了进行研究的人员的详细联系信息，以及有关进行该研究的地点的信息。

学习地点

  • 美国
    • Minnesota
      • Rochester、Minnesota、美国、55905
        • Mayo Clinic

参与标准

研究人员寻找符合特定描述的人，称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。

资格标准

适合学习的年龄

12年 至 18年 (孩子、成人)

接受健康志愿者

是的

有资格学习的性别

全部

描述

Inclusion Criteria:

  1. Age 12-18 years
  2. BMI >95% for age and gender
  3. 25 (OH) D levels less than 30 ng/ml

Exclusion Criteria:

  1. 25 (OH) D levels >30 ng/mL
  2. Serum calcium >10.4 mg/dL
  3. Serum phosphorus > 4.7 mg/dl
  4. Pregnancy or nursing
  5. Current cancer
  6. Patients on vitamin D3 supplementation exceeding 400 IU/day
  7. Hypertension defined as Blood Pressure over the 95th percentile for age, gender and height
  8. Dietary calcium intake exceeding 1500 mg/day
  9. Hepatic or renal disorders
  10. Type 1 or type 2 diabetes mellitus
  11. Subjects receiving insulin, metformin, or oral hypoglycemic medications
  12. Subjects with malabsorption disorders (celiac disease, cystic fibrosis, inflammatory bowel disease)

学习计划

本节提供研究计划的详细信息，包括研究的设计方式和研究的衡量标准。

研究是如何设计的？

设计细节

  • 主要用途：预防
  • 分配：不适用
  • 介入模型：单组作业
  • 屏蔽：无（打开标签）

武器和干预

参与者组/臂
干预/治疗
实验性的：Vitamin D3
Vitamin D3 supplementation at 100,000 IU once a month for 3 months
膳食补充剂：Vitamin D3
Vitamin D 3 at 100,000 IU once a month for 3 months
其他名称：
  • 胆钙化醇

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
Flow Mediated Dilatation (FMD)
大体时间：baseline, 3 months
Endothelial function was assessed by FMD, via a high-resolution Doppler ultrasonography examination of the right brachial artery. FMD was calculated as the maximal percentage increase in brachial artery diameter (BAD) from baseline after the release of cuff occlusion.
baseline, 3 months

次要结果测量

结果测量
措施说明
大体时间
25-hydroxy Vitamin D (25[OH]D) Levels
大体时间：baseline, 3 months
25(OH)D was measured using liquid chromatography-tandem mass spectrometry. Total 25(OH)D concentrations of each sample was calculated using internal standard, 25(OH)D_2 and 25(OH)D_3.
baseline, 3 months
Total Cholesterol
大体时间：baseline, 3 months
Total cholesterol levels were measured by an enzymatic colorimetric assay.
baseline, 3 months
Triglycerides
大体时间：baseline, 3 months
Total triglyceride levels were measured by an enzymatic colorimetric assay.
baseline, 3 months
Body Mass Index
大体时间：baseline, 3 months
Body Mass Index (BMI) is a health index for comparing weight to height. BMI is a person's weight in kilograms (kg) divided by his or her height in meters squared. The body mass index is an indication if a person is at a suitable weight for his height on an approximation of body fat. A body mass index of under 20 is considered to be underweight, while a body mass index between 20 to 25 is considered healthy. A body mass index in the range of 25 to 30 is regarded as overweight. A body mass index over 30 is regarded as obese.
baseline, 3 months
International Physical Activity Questionnaire (IPAQ) Short Form Score
大体时间：baseline, 3 months
The IPAQ short form used asked 7 questions about activities in the last 7 days, covering vigorous physical activities, moderate activities, walking, and sitting, asking for days per week, hours per day or minutes per day. The score is reported in metabolic equivalent (MET)-minutes per week. Possible scores could range from 0 (inactive) to greater than 3000 MET-minutes/week (highly active). The definition of high activity was vigorous intensity activity on at least 3 days achieving a minimum total activity of at least 1500 MET-minutes/week OR 7 days of any combination of walking, moderate-intensity or vigorous-intensity activities achieving a minimum total physical activity of at least 3000 MET-minutes/week. Therefore a score of > 3000 MET-minutes/week was possible.
baseline, 3 months
Calcium Intake Per Day
大体时间：baseline, 3 months
Calcium intake was measured using the validated Short Calcium Questionnaire (SCQ). This questionnaire is in the form of an spreadsheet, and asks the participant to enter the number of servings per week of various food items and vitamin or mineral supplements. The spreadsheet calculates the daily calcium intake (mg/day) from the data entered.
baseline, 3 months
Serum Parathyroid Hormone (PTH)
大体时间：baseline, 3 months
A parathyroid hormone (PTH) blood test measures the level of parathyroid hormone in the blood. This test is used to help identify hyperparathyroidism, to find the cause of abnormal calcium levels, or to check the status of chronic kidney disease. PTH controls calcium and phosphorus levels in the blood. PTH was measured by a two-site chemiluminescent immunometric assay.
baseline, 3 months
Fasting Glucose
大体时间：baseline, 3 months
Plasma glucose was measured by hexokinase enzymatic assay.
baseline, 3 months
Fasting Insulin
大体时间：baseline, 3 months
Serum insulin was measured using commercial electrochemiluminescence immunoassay kits.
baseline, 3 months
Homeostatic Model Assessment of Insulin Resistance Index (HOMA-IR)
大体时间：baseline, 3 months
This calculation measures insulin resistance, and requires U.S. standard units. The healthy range is 0.5 to 1.4. Less than 1.0 means the subject is insulin-sensitive, which is optimal. Above 1.9 indicates early insulin resistance. Above 2.9 indicates significant insulin resistance. The HOMA-IR was calculated as: HOMA-IR = fasting serum glucose (mmol/L) x fasting insulin (mU/mL)/22.5.
baseline, 3 months
High Sensitivity C-reactive Protein (Hs-CRP)
大体时间：baseline, 3 months
A high-sensitivity C-reactive protein (hs-CRP) test may be used to help evaluate an individual for risk of cardiovascular disease (CVD). C-reactive protein (CRP) is a protein that increases in the blood with inflammation. Studies have suggested that a persistent low level of inflammation plays a major role in atherosclerosis, the narrowing of blood vessels due to build-up of cholesterol and other lipids, which is often associated with CVD. The hs-CRP test accurately measures low levels of C-reactive protein to identify low but persistent levels of inflammation and thus helps predict a person's risk of developing CVD. hs-CRP was measured using particle-enhanced immunonephelometry.
baseline, 3 months
Low-density Lipoprotein Cholesterol (LDL) Cholesterol Levels
大体时间：baseline, 3 months
The test for low-density lipoprotein cholesterol is used as part of a lipid profile to predict an individual's risk of developing heart disease. A desirable level is <3.36 mmol/L; borderline high is 3.36 - 4.11 mmol/L; high is >/= 4.14 mmol/L. LDL cholesterol was calculated as: LDL = Total cholesterol - HDL cholesterol - Triglycerides/5.
baseline, 3 months
High Density Lipoprotein (HDL) Cholesterol Levels
大体时间：baseline, 3 months
Total HDL cholesterol levels were measured by an enzymatic colorimetric assay. The test for high-density lipoprotein cholesterol (HDL-C) is used along with other lipid tests to screen for unhealthy levels of lipids and to determine the risk of developing heart disease. If a subject has a negative risk factor, a desirable HDL level would be >/= 1.55 mmol/L.
baseline, 3 months
Urine Calcium to Creatinine Ratio
大体时间：baseline, 3 months
Urine calcium/creatinine ratio (unit mg/g) on random urine sample was calculated by dividing calcium in mg by creatinine in g.
baseline, 3 months
Reactive Hyperemia Index (RHI)
大体时间：baseline, 3 months
The cuff of a sphygmomanometer was placed on the forearm and inflated to 50 mm Hg above the participant's systolic blood pressure for a period of 5 min. The increase in resting brachial blood flow was calculated as the maximum flow recorded in the first 15 seconds after cuff deflation and expressed as a percentage increase from baseline reactive. Higher values are considered normal or improved endothelial function.
baseline, 3 months

合作者和调查者

在这里您可以找到参与这项研究的人员和组织。

赞助

Mayo Clinic

出版物和有用的链接

负责输入研究信息的人员自愿提供这些出版物。这些可能与研究有关。

一般刊物

研究记录日期

这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查，以确保它们在发布到公共网站之前符合特定的质量控制标准。

研究主要日期

学习开始

2012年11月1日

初级完成 (实际的)

2013年12月1日

研究完成 (实际的)

2013年12月1日

研究注册日期

首次提交

2012年11月16日

首先提交符合 QC 标准的

2012年12月6日

首次发布 (估计)

2012年12月10日

研究记录更新

最后更新发布 (估计)

2016年5月2日

上次提交的符合 QC 标准的更新

2016年3月30日

最后验证

2016年3月1日

更多信息

与本研究相关的术语

关键字

其他相关的 MeSH 术语

其他研究编号

  • 12-006349
  • UL1TR000135 (美国 NIH 拨款/合同)

此信息直接从 clinicaltrials.gov 网站检索，没有任何更改。如果您有任何更改、删除或更新研究详细信息的请求，请联系 register@clinicaltrials.gov. clinicaltrials.gov 上实施更改，我们的网站上也会自动更新.

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