Anorexia nervosa Quiz: Ace Your Exams

A 16-year-old girl is brought to the physician by her parent due to the absence of consistent menstrual cycles. The patient has not had any menstrual cycles for the last 5 months. Menarche occurred at age 13. She has recently joined the gymnastics team at school and is trying to exercise and lose weight. Her parent is worried about her eating habits because she has been eating less to lose weight even though she is already thin. The patient tells the physician she is afraid of gaining weight and that she “does not like how her body looks.” Her BMI is 17.4 kg/m2. On physical examination, hair loss is noticed on the head, and the breasts are Tanner stage V. There is growth of soft, unpigmented hair over the arms. Which of the following hormonal changes is most likely responsible for this patient’s amenorrhea?