Clinical trial NCT01537094: The Effect of Vitamin C on Growth Hormone Secretion
Official title: The Effect of Vitamin C on Growth Hormone Secretion
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: PHASE2
Conditions: Obese
Disorder of Vitamin C
Growth Hormone Secretion Abnormality
Keywords: low vitamin c
reduced growth hormone secretion
Lead sponsor: Massachusetts General Hospital
Sponsor class: OTHER
First posted: 2012-02-23
Enrollment: 0
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.


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.

Primary outcomes:
measure: Change from Baseline in GH secretion at 4 weeks
timeFrame: Change from Baseline to 4 weeks
Secondary outcomes:
Other outcomes:
Locations:
city: Boston
country: United States
facility: Massachusetts General Hospital
state: Massachusetts
Study officials:
affiliation: Massachusetts General Hospital
name: Hideo Makimura, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: