The Effect of Vitamin C on Growth Hormone Secretion

Tracking Information
First Submitted Date ICMJE	February 10, 2012
First Posted Date ICMJE	February 23, 2012
Last Update Posted Date	December 13, 2013
Study Start Date ICMJE	December 2013
Actual Primary Completion Date	December 2013 (Final data collection date for primary outcome measure)
Current Primary Outcome Measures ICMJE; (submitted: February 16, 2012)	Change from Baseline in GH secretion at 4 weeks [ Time Frame: Change from Baseline to 4 weeks ]; 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.
Original Primary Outcome Measures ICMJE	Same as current
Change History	Complete list of historical versions of study NCT01537094 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures ICMJE	Not Provided
Original Secondary Outcome Measures ICMJE	Not Provided
Current Other Outcome Measures ICMJE	Not Provided
Original Other Outcome Measures ICMJE	Not Provided
Descriptive Information
Brief Title ICMJE	The Effect of Vitamin C on Growth Hormone Secretion
Official Title ICMJE	The Effect of Vitamin C on Growth Hormone Secretion
Brief Summary	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.
Detailed Description	Not Provided
Study Type ICMJE	Interventional
Study Phase	Phase 2
Study Design ICMJE	Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor); Primary Purpose: Treatment
Condition ICMJE	Obese; Disorder of Vitamin C; Growth Hormone Secretion Abnormality
Intervention ICMJE	Dietary Supplement: Placebo; Dietary Supplement: Vitamin C 250 mg once daily; Dietary Supplement: Vitamin C 1,000 mg once daily
Study Arms	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
Publications *	Not Provided
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status ICMJE	Withdrawn
Actual Enrollment ICMJE; (submitted: December 11, 2013)	0
Original Estimated Enrollment ICMJE; (submitted: February 16, 2012)	45
Actual Study Completion Date	December 2013
Actual Primary Completion Date	December 2013 (Final data collection date for primary outcome measure)
Eligibility Criteria ICMJE	Inclusion Criteria: Men and women age 18-60; BMI ≥ 30 kg/m2; Waist circumference ≥ 102 cm in men and ≥ 88 cm in women; Plasma vitamin C concentration ≤ 23 µmol/l; Peak stimulated GH ≤ 4.2 µg/l upon GHRH-arginine stimulation test Exclusion Criteria: History of hypopituitarism, pituitary surgery, pituitary/brain radiation, recent traumatic brain injury or any other condition known to affect the GH axis.; History of severe chronic illness including anemia, chronic kidney disease, liver disease, oxygen dependent COPD or HIV; Subjects on testosterone, glucocorticoids, anabolic steroids, GHRH, GH or IGF-1 within 3 months of enrollment; Use of dietary supplements including vitamin C or once daily multi-vitamins; Subjects with Hgb < 912 g/dL, SGOT > 2.5x upper limit of normal or Creatinine > 1.5 mg/dL; Subjects with poorly controlled diabetes, defined as HbA1c > 8%.; Changes in lipid lowering or anti-hypertensive regimen within 3months of screening; 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; Any condition judged by the patient's physician to cause this clinical trial to be detrimental to the patient.
Sex/Gender	Sexes Eligible for Study: All
Ages	18 Years to 60 Years (Adult)
Accepts Healthy Volunteers	No
Contacts ICMJE	Contact information is only displayed when the study is recruiting subjects
Listed Location Countries ICMJE	United States
Removed Location Countries
Administrative Information
NCT Number ICMJE	NCT01537094
Other Study ID Numbers ICMJE	2011-P-002912
Has Data Monitoring Committee	No
U.S. FDA-regulated Product	Not Provided
IPD Sharing Statement	Not Provided
Responsible Party	Hideo Makimura, Massachusetts General Hospital
Study Sponsor ICMJE	Massachusetts General Hospital
Collaborators ICMJE	Not Provided
Investigators ICMJE	Principal Investigator: Hideo Makimura, MD, PhD Massachusetts General Hospital
PRS Account	Massachusetts General Hospital
Verification Date	December 2013
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP