Primary Outcome Measures:
- Change in visceral adipose tissue volume [ Time Frame: Measured at baseline and Months 6 and 12 ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- Change in growth hormone pulse characteristics as assessed by overnight frequent sampling of growth hormone [ Time Frame: Measured at baseline and Month 12 ] [ Designated as safety issue: No ]
- Change in carotid intima-media thickness [ Time Frame: Measured at baseline and Months 6 and 12 ] [ Designated as safety issue: No ]
- Change in lipid profile (total cholesterol, high-density lipoproteins [HDL] cholesterol, low-density lipoproteins [LDL] cholesterol, triglycerides) [ Time Frame: Measured at baseline and Months 6 and 12 ] [ Designated as safety issue: No ]
- Change in glucose tolerance as measured by oral glucose tolerance test [ Time Frame: Measured at baseline and Months 6 and 12 ] [ Designated as safety issue: Yes ]
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.