Patient resources and links for Manhattan Endocrinologists and top doctor Dr. Olga Leonardi, MD. Appointment process, diabetes, thyroid, and endocrine groups. Olga Leonardi, M.D., Manhattan Endocrinologist - Manhattan Endocrinologists patient resources Get Directions (212) 414-3111 (212) 414-8248 frontdesk@manhattanendocrinologist.com.