NOTE: If screening TSH is abnormal, obtain free thyroxin index. If the free thyroxine index is normal, the subject may enter the study. If the free thyroxin index is low, the subject may be treated with thyroid hormone replacement medication and enter the study once the free thyroxin index is corrected. If the free thyroxin index is elevated indicating hyperthyroidism, the subject should not enroll in the study.