 - Physical Examination: The investigators will measure the participants weight, height, blood pressure, heart rate and respiratory rate, and waist circumference. If the participant is under age 21 years, a pediatric endocrinologist will check how far she is along in puberty. For both boys and girls, pubic hair growth will be checked. For girls, breast development will be checked. For boys, testicular development will be checked. This examination will take approximately 2 minutes and will be done in a private room. 