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Effect of Vitamin D Supplementation on Endothelial Function in Obese Adolescents

30. března 2016 aktualizováno: 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.

Přehled studie

Postavení

Dokončeno

Podmínky

Intervence / Léčba

Detailní popis

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.

Typ studie

Intervenční

Zápis (Aktuální)

19

Fáze

  • Fáze 1

Kontakty a umístění

Tato část poskytuje kontaktní údaje pro ty, kteří studii provádějí, a informace o tom, kde se tato studie provádí.

Studijní místa

  • Spojené státy
    • Minnesota
      • Rochester, Minnesota, Spojené státy, 55905
        • Mayo Clinic

Kritéria účasti

Výzkumníci hledají lidi, kteří odpovídají určitému popisu, kterému se říká kritéria způsobilosti. Některé příklady těchto kritérií jsou celkový zdravotní stav osoby nebo předchozí léčba.

Kritéria způsobilosti

Věk způsobilý ke studiu

12 let až 18 let (Dítě, Dospělý)

Přijímá zdravé dobrovolníky

Ano

Pohlaví způsobilá ke studiu

Všechno

Popis

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)

Studijní plán

Tato část poskytuje podrobnosti o studijním plánu, včetně toho, jak je studie navržena a co studie měří.

Jak je studie koncipována?

Detaily designu

  • Primární účel: Prevence
  • Přidělení: N/A
  • Intervenční model: Přiřazení jedné skupiny
  • Maskování: Žádné (otevřený štítek)

Zbraně a zásahy

Skupina účastníků / Arm
Intervence / Léčba
Experimentální: Vitamin D3
Vitamin D3 supplementation at 100,000 IU once a month for 3 months
Doplněk stravy: Vitamin D3
Vitamin D 3 at 100,000 IU once a month for 3 months
Ostatní jména:
  • Cholekalciferol

Co je měření studie?

Primární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
Flow Mediated Dilatation (FMD)
Časové okno: 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

Sekundární výstupní opatření

Měření výsledku
Popis opatření
Časové okno
25-hydroxy Vitamin D (25[OH]D) Levels
Časové okno: 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
Časové okno: baseline, 3 months
Total cholesterol levels were measured by an enzymatic colorimetric assay.
baseline, 3 months
Triglycerides
Časové okno: baseline, 3 months
Total triglyceride levels were measured by an enzymatic colorimetric assay.
baseline, 3 months
Body Mass Index
Časové okno: 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
Časové okno: 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
Časové okno: 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)
Časové okno: 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
Časové okno: baseline, 3 months
Plasma glucose was measured by hexokinase enzymatic assay.
baseline, 3 months
Fasting Insulin
Časové okno: baseline, 3 months
Serum insulin was measured using commercial electrochemiluminescence immunoassay kits.
baseline, 3 months
Homeostatic Model Assessment of Insulin Resistance Index (HOMA-IR)
Časové okno: 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)
Časové okno: 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
Časové okno: 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
Časové okno: 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
Časové okno: 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)
Časové okno: 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

Spolupracovníci a vyšetřovatelé

Zde najdete lidi a organizace zapojené do této studie.

Sponzor

Mayo Clinic

Publikace a užitečné odkazy

Osoba odpovědná za zadávání informací o studiu tyto publikace poskytuje dobrovolně. Mohou se týkat čehokoli, co souvisí se studiem.

Obecné publikace

Termíny studijních záznamů

Tato data sledují průběh záznamů studie a předkládání souhrnných výsledků na ClinicalTrials.gov. Záznamy ze studií a hlášené výsledky jsou před zveřejněním na veřejné webové stránce přezkoumány Národní lékařskou knihovnou (NLM), aby se ujistily, že splňují specifické standardy kontroly kvality.

Hlavní termíny studia

Začátek studia

1. listopadu 2012

Primární dokončení (Aktuální)

1. prosince 2013

Dokončení studie (Aktuální)

1. prosince 2013

Termíny zápisu do studia

První předloženo

16. listopadu 2012

První předloženo, které splnilo kritéria kontroly kvality

6. prosince 2012

První zveřejněno (Odhad)

10. prosince 2012

Aktualizace studijních záznamů

Poslední zveřejněná aktualizace (Odhad)

2. května 2016

Odeslaná poslední aktualizace, která splnila kritéria kontroly kvality

30. března 2016

Naposledy ověřeno

1. března 2016

Více informací

Termíny související s touto studií

Klíčová slova

Další relevantní podmínky MeSH

Další identifikační čísla studie

  • 12-006349
  • UL1TR000135 (Grant/smlouva NIH USA)

Tyto informace byly beze změn načteny přímo z webu clinicaltrials.gov. Máte-li jakékoli požadavky na změnu, odstranění nebo aktualizaci podrobností studie, kontaktujte prosím register@clinicaltrials.gov. Jakmile bude změna implementována na clinicaltrials.gov, bude automaticky aktualizována i na našem webu .

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