Prevalence and Cardiovascular Effects of Growth Hormone Deficiency in Abdominal Obesity

Inclusion Criteria for Obesity: * Body mass index (BMI) greater than or equal to 30 kg/m2 * Abdominal obesity, defined as waist circumference greater than or equal to 102 cm in men and greater than or equal to 88 cm in women Inclusion Criteria for Lean Controls: * BMI less than 25 kg/m2 * Waist circumference less than 102 cm in men and less than 88 cm in women Exclusion Criteria for both groups: * Obesity due to known secondary causes * Taking any weight lowering drugs * Previous bariatric surgery * Use of the following compounds within the 3 months prior to study entry: estrogen, progesterone, GH, GHRH, glucocorticoids, megesterol acetate, antidiabetic agents, oral contraceptive pills, or any other hormone or drug known to affect GH levels * Change in lipid lowering or antihypertensive regimen within 3 months prior to study entry * Use of testosterone or hormone replacement therapy * Previously known diabetes mellitus or other severe chronic illness * Hemoglobin less than 11.0 g/dL, creatinine greater than 1.5 mg/dL, or serum glutamic oxaloacetic transaminase (SGOT) greater than 2.5 times the upper limit of normal * Follicle stimulating hormone (FSH) greater than 20 IU/L in women * Positive urine pregnancy test * Prior history of pituitary disease, pituitary surgery, head irradiation, or any other condition known to affect the GH axis