CASE FILES: BIOCHEMISTRY
A N SW E R S TO C A SE 39: A N O R E X IA N E R V O SA
A thin 16-year-old girl who is obsessed with her body appearance
and weight to the point of not wanting to eat and exercising excessively.
Diagnosis: Anorexia nervosa. This is differentiated from bulimia
because she denies binge eating with associated guilty feelings.
Medical complications: Dry skin, lanugo, bradycardia, hypotension,
dependent edema, hypothermia, anemia, osteoporosis, infertility, cardiac
failure, and even death.
Menstrual complications: Amenorrhea secondary to depression of
the hypothalamic-pituitary axis. Infertility will result secondary to
C L IN IC A L C O R R E L A T IO N
Anorexia nervosa is a disease affecting primarily young women who have dis-
torted body images. Although their weight is less than 30 percent under ideal
body weight, they see themselves as overweight. Anorectics often use diuretic
and laxative agents to accomplish their weight loss. Patients with bulimia, who
usually induce emesis, may be at normal weight or even above ideal body
weight; in contrast, anorectics are almost always under ideal body weight.
Often, affected individuals become amenorrheic, have fine lanugo hair, and
become hypothermic. Therapy must be multifaceted and include family and
individual counseling, behavioral modification, and possibly medication.
Severe cases may be fatal.
A PPR O A C H TO A M IN O A C ID A N D N E G A T IV E
PR O T E IN B A L A N C E
Know about protein digestion and amino acid absorption.
Be familiar with nitrogen addition and removal from amino acids.
Understand amino acid metabolism in various tissues (muscle, gas-
trointestinal [GI], kidney).
Know the special products derived from amino acids.
Anorexia nervosa: A mental disorder in which the patient has an extreme
fear of becoming obese and therefore an aversion to food. The disorder
usually occurs in young women and can result in death if the condition
is not treated successfully.