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This study has been withdrawn prior to enrollment.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

Tracking Information

First Received Date ^ICMJE

February 10, 2012

Last Updated Date

December 11, 2013

Start Date ^ICMJE

December 2013

Primary Completion Date

December 2013 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures ^ICMJE

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 ^ICMJE

Same as current

Change History

Complete list of historical versions of study NCT01537094 on ClinicalTrials.gov Archive Site

Current Secondary Outcome Measures ^ICMJE

Not Provided

Original Secondary Outcome Measures ^ICMJE

Not Provided

Current Other Outcome Measures ^ICMJE

Not Provided

Original Other Outcome Measures ^ICMJE

Not Provided

Descriptive Information

Brief Title ^ICMJE

The Effect of Vitamin C on Growth Hormone Secretion

Official Title ^ICMJE

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 ^ICMJE

Interventional

Study Phase

Phase 2

Study Design ^ICMJE

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment

Condition ^ICMJE

Obese
Disorder of Vitamin C
Growth Hormone Secretion Abnormality

Intervention ^ICMJE

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

* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.

Recruitment Information

Recruitment Status ^ICMJE

Withdrawn

Enrollment ^ICMJE

Completion Date

December 2013

Primary Completion Date

December 2013 (Final data collection date for primary outcome measure)

Eligibility Criteria ^ICMJE

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.

Sex/Gender

Sexes Eligible for Study:

All

Ages

18 Years to 60 Years (Adult)

Accepts Healthy Volunteers

Contacts ^ICMJE

Contact information is only displayed when the study is recruiting subjects

Listed Location Countries ^ICMJE

United States

Removed Location Countries

Administrative Information

NCT Number ^ICMJE

NCT01537094

Other Study ID Numbers ^ICMJE

2011-P-002912

Has Data Monitoring Committee

U.S. FDA-regulated Product

Not Provided

IPD Sharing Statement

Not Provided

Responsible Party

Hideo Makimura, Massachusetts General Hospital

Study Sponsor ^ICMJE

Massachusetts General Hospital

Collaborators ^ICMJE

Not Provided

Investigators ^ICMJE

Principal Investigator:

Hideo Makimura, MD, PhD

Massachusetts General Hospital

PRS Account

Massachusetts General Hospital

Verification Date

December 2013

^ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP

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