2. After overnight fasting, an indwelling catheter will be inserted in a peripheral vein. Blood for baseline hormonal evaluation (8-9 AM) including: serum free T4 (FT4), TSH, cortisol, GH, IGF-1, prolactin, LH, FSH, Estradiol (in females) and total testosterone (in males). Menstruating females will be studied during follicular phase. Serum IGF-1, testosterone, estradiol and gonadotropin levels will be interpreted in accordance with the patients' age.