Cortisol secretion and metabolism in anorexia nervosa

Area of Science:

• Endocrinology
• Metabolic Disorders
• Neuroscience

Background:

• Anorexia nervosa is associated with significant physiological disturbances.
• Cortisol, a key stress hormone, plays a crucial role in metabolic regulation.
• Previous studies suggest potential alterations in the hypothalamic-pituitary-adrenal (HPA) axis in anorexia nervosa.

Purpose of the Study:

• To investigate cortisol secretion and metabolism in women with anorexia nervosa.
• To compare cortisol parameters in patients with anorexia nervosa to healthy controls.
• To explore the relationship between cortisol metabolism and thyroid hormone levels in anorexia nervosa.

Main Methods:

• Measured 24-hour mean plasma cortisol concentration, cortisol half-life, and metabolic clearance rate in 10 women with anorexia nervosa and controls.
• Assessed cortisol production and urinary cortisol levels.
• Performed thyroid-function studies, including measurements of total and free thyroxine, thyrotropin, and plasma tri-iodothyronine.
• Administered tri-iodothyronine to five patients and re-evaluated metabolic parameters.

Main Results:

• Women with anorexia nervosa had significantly higher mean plasma cortisol concentrations (8.9 vs. 4.9 mug/dL).
• Cortisol half-life was prolonged (78 vs. 60 minutes), and metabolic clearance rate was decreased (177 vs. 359 L/day) in patients.
• Patients exhibited low plasma tri-iodothyronine levels (52.7 vs. 137.8 ng/dL), with normalization of metabolic abnormalities after tri-iodothyronine administration.

Conclusions:

• Anorexia nervosa is characterized by altered cortisol metabolism, resembling findings in hypothyroid patients.
• Low tri-iodothyronine levels contribute to these metabolic abnormalities.
• Tri-iodothyronine administration can improve cortisol metabolic disturbances in anorexia nervosa.