Growth Hormone as a Determinant of Weight Regulation

With the alarming increase in the prevalence of obesity, identifying factors that predispose individuals to weight-gain is of critical importance. Even when caloric intake and physical activity levels are well controlled, susceptibility for weight-gain is heterogeneous. Basal metabolic rate (BMR) represents the largest portion of daily energy expenditure in normal adults, and as such, variability in BMR among individuals can be a major factor in determining the susceptibility for gaining weight. However, factors responsible for this variability in BMR and resistance to weight-gain remain unclear. Our preliminary data indicate that high-normal growth hormone (GH) concentration is associated with resistance to weight-gain in rats when overfed and greater weight-loss in humans when underfed. In addition, we have found that the pulsatility of GH secretion has profound effects on several metabolic processes.

Official Title

Growth Hormone as a Determinant of Weight Regulation

Conditions

• Obesity

Study Type

Interventional

Study Design

Diagnostic, Randomised, Open Label, Placebo Control, Parallel Assignment, Efficacy Study

Further Details

Primary Outcome Measures:

• Basal metabolic rate 
• Growth hormone 
• Changes in body weight and body composition 
• Whole body protein turnover 
• Muscle and liver protein synthesis
• Lipolytic rate
• Fatty acid/triglyceride cycling

Study Start

September 2005

Eligibility & Criteria

Eligibility

• Ages Eligible for Study: 18 Years to 35 Years
• Genders Eligible for Study: Both
• Accepts Healthy Volunteers: Yes

Inclusion Criteria:

• Age = 21-35 years Weight stable (< ± 5 pound over past 6 months) Premenopausal (women only) Body mass index 18 – 26 kg/m2 Must be willing to be randomised to receive GH infusion during 2 week GCRC visit

Exclusion Criteria:

• Evidence of metabolic or cardiovascular disease Pregnancy (women only) Hyperlipidemia (fasting plasma triglyceride concentration > 150 mg/dl) Hematocrit < 34% Liver Function test abnormalities participating in a regular exercise program (> 2 h/week) taking any prescription medication (except birth control)

Total Enrolment

105

Contact Details

Lisa Locke, RD
1 734/647-980
lislocke@umich.edu    

Locations:

United States, Michigan
University of Michigan