Suprarrenal

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286 PHYSIOLOGY CASES ANO PROBLEMS

Adrenocortical Insufficiency: Addison's Disease

Case Susan Oglesby is a 41-year-old divorced mother of two teenagers. She has always been inexcellent health. She recently saw her physician because of several unex- plained symptoms, including weight loss of 15 lb, extreme fatigue, and decreased body hair in the axillary and pubic regions. Inaddition, her skin was very tanned, even though she had not been in the sun. Susan hadn't had a menstrual period in 3 months; she knew she wasn't pregnant and wondered whether she was experi- encing earlymenopause.
In her physician's office, Susan appeared very thin, with sunken eyes and de- creased skin turgor. When she was supine (1ying), her blood pressure was 90/60 and her pulse rate was 95beats/min. When she was standing, her blood pressure was 70/35 and her pulse rate was 120 beats/min. Her skin was deeply pigmented, es- pecia11y her nipples and the creases in the palms of her hands.Susan's physician ordered laboratory tests (Table 6-5).

Venous blood Na+ K+
Osmolarity Glucose (fasting) Cortisol Aldosterone ACTH

126 mEq/L (normal, 140 mEq/L) 5.7 mEq/L (normal, 4.5 mEq/L)265 mOsm/L (normal, 290 mOsm/L) 50 mg!dl (normal, 70-100 mg!dl) Decreased Decreased Increased

ACTH, adrenocorticotropic hormone.

Results of an adrenocorticotropic hormone (ACTH) stimulationtest were negative (i.e., there was no increase in the serum level of cortisol or aldosterone). Based on the symptoms, physical examination, laboratory values, and results of the ACTH stimulation test,Susan was diagnosed with primary adrenal insufficiency (Addison's disease). Susan's physician prescribed daily treatment with hydrocortisone (a synthetic glucocorticoid) and fludrocortisone (asynthetic mineralocorticoid). Susan was instructed to take hydrocortisone in two divided doses, with a larger dose at 8 A.M. and a smaller dose at 1 P.M.
At a follow-up visit 2 weeks later, Susan's...