The Effect of Vitamin C on Growth Hormone Secretion

This study has been withdrawn prior to enrollment.

(Unable to obtain funding to initiate the study. No subjects were enrolled.)

Sponsor:

Information provided by (Responsible Party):

Hideo Makimura, Massachusetts General Hospital

ClinicalTrials.gov Identifier:

NCT01537094

First received: February 10, 2012

Last updated: December 11, 2013

Last verified: December 2013

History of Changes

Purpose

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.

Condition	Intervention	Phase
Obese Disorder of Vitamin C Growth Hormone Secretion Abnormality	Dietary Supplement: Placebo Dietary Supplement: Vitamin C 250 mg once daily Dietary Supplement: Vitamin C 1,000 mg once daily	Phase 2


Study Type:	Interventional
Study Design:	Allocation: Randomized Intervention Model: Parallel Assignment Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor) Primary Purpose: Treatment
Official Title:	The Effect of Vitamin C on Growth Hormone Secretion

Resource links provided by NLM:

MedlinePlus related topics: Hormones Vitamin C

Drug Information available for: Ascorbic acid Sodium ascorbate Magnesium ascorbate

U.S. FDA Resources

Further study details as provided by Hideo Makimura, Massachusetts General Hospital:

Primary Outcome Measures:

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.


Enrollment:	0
Study Start Date:	December 2013
Study Completion Date:	December 2013
Primary Completion Date:	December 2013 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
Active Comparator: Vitamin C low dose vitamin C 250 mg oral once daily	Dietary Supplement: Vitamin C 250 mg once daily
Active Comparator: Vitamin C high dose vitamin C 1,000 mg oral once daily	Dietary Supplement: Vitamin C 1,000 mg once daily
Placebo Comparator: Placebo Placebo oral once daily	Dietary Supplement: Placebo

Eligibility


Ages Eligible for Study:	18 Years to 60 Years (Adult)
Sexes Eligible for Study:	All
Accepts Healthy Volunteers:	No

Criteria

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.

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT01537094

Locations


United States, Massachusetts
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114

Sponsors and Collaborators

Massachusetts General Hospital

Investigators


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

More Information


Responsible Party:	Hideo Makimura, Assistant Professor of Medicine, Massachusetts General Hospital
ClinicalTrials.gov Identifier:	NCT01537094 History of Changes
Other Study ID Numbers:	2011-P-002912
Study First Received:	February 10, 2012
Last Updated:	December 11, 2013

Keywords provided by Hideo Makimura, Massachusetts General Hospital:


low vitamin c reduced growth hormone secretion

Additional relevant MeSH terms:


Vitamins Ascorbic Acid Hormones Micronutrients Growth Substances	Physiological Effects of Drugs Hormones, Hormone Substitutes, and Hormone Antagonists Antioxidants Molecular Mechanisms of Pharmacological Action Protective Agents

ClinicalTrials.gov processed this record on May 25, 2017

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