The Effect of Vitamin C on Growth Hormone Secretion

Obese Clinical Trial

Official title:

The Effect of Vitamin C on Growth Hormone Secretion

Clinical Trial Details — Status: Withdrawn

Administrative data

• NCT number: NCT01537094
• Other study ID #: 2011-P-002912
• Status: Withdrawn
• Phase: Phase 2
• First received: February 10, 2012
• Last updated: December 11, 2013
• Start date: December 2013
• Est. completion date: December 2013

Study information

• Verified date: December 2013
• Source: Massachusetts General Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Withdrawn
• Enrollment: 0
• Est. completion date: December 2013
• Est. primary completion date: December 2013
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 60 Years

Eligibility

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.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

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

Intervention

Dietary Supplement:
• Placebo

• Vitamin C 250 mg once daily

• Vitamin C 1,000 mg once daily

Locations

Country	Name	City	State
United States	Massachusetts General Hospital	Boston	Massachusetts

Sponsors (1)

Lead Sponsor	Collaborator
Massachusetts General Hospital

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change from Baseline in GH secretion at 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.	Change from Baseline to 4 weeks	No