The Effect of Vitamin C on Growth Hormone Secretion

This study has been withdrawn prior to enrollment.
(Unable to obtain funding to initiate the study. No subjects were enrolled.)
Sponsor:
Information provided by (Responsible Party):
Hideo Makimura, Massachusetts General Hospital
ClinicalTrials.gov Identifier:
NCT01537094
First received: February 10, 2012
Last updated: December 11, 2013
Last verified: December 2013

February 10, 2012
December 11, 2013
December 2013
December 2013   (final data collection date for primary outcome measure)
Change from Baseline in GH secretion at 4 weeks [ Time Frame: Change from Baseline to 4 weeks ] [ Designated as safety issue: No ]
GH secretion will be assessed by overnight frequent blood sampling to assess maximum GH, nadir GH, mean overnight GH, as well as parameters of pulsatile secretion.
Same as current
Complete list of historical versions of study NCT01537094 on ClinicalTrials.gov Archive Site
Not Provided
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The Effect of Vitamin C on Growth Hormone Secretion
The Effect of Vitamin C on Growth Hormone Secretion

Obesity is associated with reduced growth hormone (GH) secretion. GH secretion is regulated by nutritional stimuli including fasting, insulin, glucose and free fatty acids. However, the role of micronutrients, such as vitamins, on GH secretion has not been investigated in much detail. Vitamin C levels are also reduced in obesity, and the investigators recently demonstrated a possible role for dietary vitamin C intake in the regulation of GH secretion in two preliminary retrospective studies. The investigators therefore propose a more detailed prospective physiological study to examine the effects of increasing dietary vitamin C intake on GH secretion in a physiologic, intervention study. The investigators hypothesize that increasing vitamin C concentrations in obese subjects with sub-optimal plasma vitamin C levels and reduced GH secretion will increase GH secretion.

Not Provided
Interventional
Phase 2
Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
  • Obese
  • Disorder of Vitamin C
  • Growth Hormone Secretion Abnormality
  • Dietary Supplement: Placebo
  • Dietary Supplement: Vitamin C 250 mg once daily
  • Dietary Supplement: Vitamin C 1,000 mg once daily
  • Active Comparator: Vitamin C low dose
    vitamin C 250 mg oral once daily
    Intervention: Dietary Supplement: Vitamin C 250 mg once daily
  • Active Comparator: Vitamin C high dose
    vitamin C 1,000 mg oral once daily
    Intervention: Dietary Supplement: Vitamin C 1,000 mg once daily
  • Placebo Comparator: Placebo
    Placebo oral once daily
    Intervention: Dietary Supplement: Placebo
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Withdrawn
0
December 2013
December 2013   (final data collection date for primary outcome measure)

Inclusion Criteria:

  1. Men and women age 18-60
  2. BMI ≥ 30 kg/m2
  3. Waist circumference ≥ 102 cm in men and ≥ 88 cm in women
  4. Plasma vitamin C concentration ≤ 23 µmol/l
  5. Peak stimulated GH ≤ 4.2 µg/l upon GHRH-arginine stimulation test

Exclusion Criteria:

  1. History of hypopituitarism, pituitary surgery, pituitary/brain radiation, recent traumatic brain injury or any other condition known to affect the GH axis.
  2. History of severe chronic illness including anemia, chronic kidney disease, liver disease, oxygen dependent COPD or HIV
  3. Subjects on testosterone, glucocorticoids, anabolic steroids, GHRH, GH or IGF-1 within 3 months of enrollment
  4. Use of dietary supplements including vitamin C or once daily multi-vitamins
  5. Subjects with Hgb < 912 g/dL, SGOT > 2.5x upper limit of normal or Creatinine > 1.5 mg/dL
  6. Subjects with poorly controlled diabetes, defined as HbA1c > 8%.
  7. Changes in lipid lowering or anti-hypertensive regimen within 3months of screening
  8. Subject is currently enrolled in another investigational device or drug trial(s), or subject has received other investigational agent(s) within 28 days of baseline visit
  9. Any condition judged by the patient's physician to cause this clinical trial to be detrimental to the patient.
Both
18 Years to 60 Years
No
Contact information is only displayed when the study is recruiting subjects
United States
 
NCT01537094
2011-P-002912
No
Hideo Makimura, Massachusetts General Hospital
Massachusetts General Hospital
Not Provided
Principal Investigator: Hideo Makimura, MD, PhD Massachusetts General Hospital
Massachusetts General Hospital
December 2013

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP