The Effect of Vitamin C on Growth Hormone Secretion

• Sponsor: Massachusetts General Hospital
• Information provided by (Responsible Party): Hideo Makimura, Massachusetts General Hospital

Tracking Information

• First Submitted Date: February 10, 2012
• First Posted Date: February 23, 2012
• Last Update Posted Date: December 13, 2013
• Study Start Date: December 2013
• Actual Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures (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: Same as current
• Change History: Complete list of historical versions of study NCT01537094 on ClinicalTrials.gov Archive Site
• Current Secondary Outcome Measures: Not Provided
• Original Secondary Outcome Measures: Not Provided
• Current Other Outcome Measures: Not Provided
• Original Other Outcome Measures: Not Provided

Descriptive Information

• Brief Title: The Effect of Vitamin C on Growth Hormone Secretion
• Official Title: 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: Interventional
• Study Phase: Phase 2
• Study Design: Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor); Primary Purpose: Treatment

Condition

• Obese
• Disorder of Vitamin C
• Growth Hormone Secretion Abnormality

Intervention

• 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

Recruitment Information

• Recruitment Status: Withdrawn
• Actual Enrollment (submitted: December 11, 2013): 0
• Original Estimated Enrollment (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

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.

Sex/Gender

• Sexes Eligible for Study: All

• Ages: 18 Years to 60 Years (Adult)
• Accepts Healthy Volunteers: No
• Contacts: Contact information is only displayed when the study is recruiting subjects
• Listed Location Countries: United States

Administrative Information

• NCT Number: NCT01537094
• Other Study ID Numbers: 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: Massachusetts General Hospital
• Collaborators: Not Provided

Investigators

• Principal Investigator: Hideo Makimura, MD, PhD; Massachusetts General Hospital

• PRS Account: Massachusetts General Hospital
• Verification Date: December 2013