Clinical trial NCT00675506
Conditions: Abdominal Obesity Growth Hormone Deficiency
Keywords: Growth Hormone Releasing Hormone Growth Hormone Pulse Visceral Adipose Tissue Carotid Intima-Media Thickness
Sponsor: Massachusetts General Hospital
Start date: 2008-07-01; Completion date: 2012-01-01
Enrollment: 60 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
Obesity, a condition that occurs when a person has too much body fat, affects about 31% of people in the United States. It is associated with increased risk of diabetes, high blood pressure, high cholesterol, and cardiovascular disease. Abdominal obesity, in particular, is also associated with low levels of growth hormone, a hormone that affects rate of growth and the way the body uses energy. Growth hormone releasing hormone (GHRH) is a substance that makes the body naturally increase its own growth hormone levels. Administering GHRH to people who are obese may help return their growth hormone levels to normal and, in turn, may lead to reduced abdominal fat and improved cardiovascular function. This study will evaluate the effectiveness of synthetic GHRH in decreasing the amount of abdominal fat and improving cardiovascular function in people who are obese.

Detailed description:
Obesity, defined as having a high amount of excess body fat, is one of the most wide-spread health problems of today. A variety of factors can lead to obesity. These factors include physical inactivity, family history and genetics, metabolism, and hormone imbalance. The excess body fat in obesity increases a person's risk of a number of life-threatening diseases, including heart disease, gall stones, type 2 diabetes, and certain types of cancer. People with abdominal obesity, where fat is stored predominantly around a person's midsection, are particularly prone to weight-related diseases. Studies have shown that administration of growth hormone to obese people reduces abdominal fat, but can be associated with adverse side effects. GHRH is a natural hypothalamic peptide that stimulates growth hormone release. GHRH may be able to normalize growth hormone levels, reduce abdominal fat, and lessen risk for cardiovascular disease in people who are obese, without the associated side effects of growth hormone administration. However, further study is needed on GHRH. This study will evaluate the safety and effectiveness of synthetic GHRH in decreasing the amount of abdominal fat and improving cardiovascular function in people who are obese.

Participation is this study will last 1 year from screening and will include 9 study visits. During Visit 1, participants will undergo screening tests that will include a medical history, a physical exam, body measurements, a blood draw, a urine test, a GHRH+Arginine stimulation test, an electrocardiogram (ECG), and a test for the presence of blood in stool. Eligible participants will return within the next 3 weeks for an inpatient clinic stay for Visit 2. Participants will be asked to keep a food record of all food consumed during the 4 days before the second visit. Visit 2 will include a physical exam, a medical and smoking history, a review of current medications, body measurements, an overnight blood draw, a body metabolism evaluation, an oral glucose tolerance test, and two questionnaires. Also during Visit 2, participants will be assigned randomly to treatment with active GHRH or placebo. Participants will then be taught how to give themselves injections of the study drug, which will be taken daily for 12 months. Participants will also receive a 1-month supply of study drug and will be supplied with refills in subsequent study visits. Upon starting treatment, participants will undergo more testing, including a whole body DEXA scan, abdominal computed tomography (CT) scan, carotid ultrasound, and ECG.

Visit 3 will occur at Week 2 of treatment and will include a review of study medications, questions about any side effects experienced, vital sign measurements, a blood draw, an ECG, and, if female, a urine test. Visits 4, 5, and 7 will be identical to Visit 3 and will occur at Months 1, 3, and 9 respectively. Visit 6 will occur at Month 6 and will be identical to Visit 2 but without the overnight blood draw. Visit 8 will occur at Month 12 and will be identical to Visit 2, except no further study drug will be dispensed. At Month 13, participants will complete the final study visit, which will include repeat tests from Visit 1.

Arms: arm 1: Participants will receive treatment with growth hormone releasing hormone 1-44 (TH9507). arm 2: Participants will receive treatment with placebo medication.
Interventions: intervention 1: Growth hormone releasing hormone (GHRH) 1-44 intervention 2: Placebo
Intervention descriptions: intervention 1: 2-mg sub-cutaneous injections once daily for 12 months intervention 2: 2-mg sub-cutaneous injections once daily for 12 months

Protocol documents: