The Effect of Vitamin C on Growth Hormone Secretion

NCT01537094 | Withdrawn Phase 2

• 1 other identifier: 2011-P-002912
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 1

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.

Conditions

Obese; Disorder of Vitamin C; Growth Hormone Secretion Abnormality

Keywords

low vitamin c; reduced growth hormone secretion

Outcome Measures

Primary Outcomes (1)

• 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

Study Arms (3)

Vitamin C low dose

ACTIVE COMPARATOR

vitamin C 250 mg oral once daily

Dietary Supplement: Vitamin C 250 mg once daily

Vitamin C high dose

ACTIVE COMPARATOR

vitamin C 1,000 mg oral once daily

Dietary Supplement: Vitamin C 1,000 mg once daily

Placebo

PLACEBO COMPARATOR

Placebo oral once daily

Dietary Supplement: Placebo

Interventions

Placebo DIETARY_SUPPLEMENT

Placebo

Vitamin C 250 mg once daily DIETARY_SUPPLEMENT

Vitamin C low dose

Vitamin C 1,000 mg once daily DIETARY_SUPPLEMENT

Vitamin C high dose

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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.

Sponsors & Collaborators

• Massachusetts General Hospital: lead

Study Sites (1)

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

Location

MeSH Terms

Conditions

Obesity

Interventions

Ascorbic Acid

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Sugar Acids; Acids, Acyclic; Carboxylic Acids; Organic Chemicals; Hydroxy Acids; Carbohydrates

Study Officials

• Hideo Makimura, MD, PhD

  Massachusetts General Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor of Medicine

Study Record Dates

• First Submitted: February 10, 2012
• First Posted: February 23, 2012
• Study Start: December 1, 2013
• Primary Completion: December 1, 2013
• Study Completion: December 1, 2013
• Last Updated: December 13, 2013

Record last verified: 2013-12

Locations

US (1)