The Effect of Vitamin C on Growth Hormone Secretion
| Status: | Not yet recruiting |
|---|---|
| Conditions: | Women's Studies, Endocrine |
| Therapuetic Areas: | Endocrinology, Reproductive |
| Healthy: | No |
| Age Range: | 18 - 60 |
| Updated: | 11/30/2013 |
| Start Date: | September 2014 |
| End Date: | September 2017 |
| Contact: | Hideo Makimura, MD, PhD |
| Email: | hmakimura@partners.org |
| Phone: | 617-726-8277 |
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.
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.
We found this trial at
1
site
Click here to add this to my saved trials
