Cortisol Secretion and Metabolism in Anorexia Nervosa

Abstract

We studied cortisol secretion and metabolism in 10 women with anorexia nervosa. The 24-hour mean plasma cortisol concentration was 8.9 μg per deciliter (controls, 4.9) (P<0.01). Secretory patterns showed normal circadian rhythms. Cortisol half-life was prolonged from 60 to 78 minutes (P<0.01), and metabolic clearance rate was decreased from 359 to 177 liters per day (P<0.001). Cortisol production was normal (19.4 mg per day). Urinary cortisol was slightly elevated in two of five patients. These findings, as well as the increased tetrahydrocortisol/tetrahydrocortisone ratio (1.2 vs. 0.65, P<0.01), also appear in hypothyroid patients. Thyroid-function studies showed normal total and free thyroxine and thyrotropin, but low plasma tri-iodothyronine levels (52.7±13.2 vs. 137.8±24.1 ng per deciliter in the controls, P<0.001). In five additional patients with anorexia nervosa studied before and after short-term tri-iodothyronine administration, metabolic abnormalities decreased as plasma tri-iodothyronine levels rose to or above normal. (N Engl J Med 296:190–193, 1977)