Adrenal Insufficiency and Iron Deficiency in the Context of Chronic Energy Restriction

Introduction to Adrenal Insufficiency and Iron Deficiency

The combination of low cortisol and suppressed progesterone suggests hypothalamic-pituitary-adrenal axis dysfunction, potentially from chronic energy deficiency, as indicated by the International Society of Sports Nutrition 1, 2.
Low energy availability causes decreased progesterone, increased cortisol (though paradoxically this patient has low cortisol suggesting severe HPA axis suppression), and iron deficiency, according to the American College of Sports Medicine 1, 2.

Low TIBC typically indicates iron overload or chronic inflammation, not iron deficiency, as TIBC increases when serum iron concentration and stored iron are low, as stated by the European Society for Clinical Nutrition and Metabolism 3.
The elevated ferritin in the context of struggling to lose weight and low cortisol suggests functional iron deficiency in the setting of chronic energy restriction, as reported by the International Society of Sports Nutrition 1, 2.
Ferritin is an acute-phase reactant and can be falsely elevated during illness, inflammation, or stress, according to the National Institute of Diabetes and Digestive and Kidney Diseases 3.

Iron deficiency in energy-deficient individuals worsens the hypometabolic state by impairing thyroid hormone synthesis and hepatic conversion of T4 to T3, as indicated by the American College of Sports Medicine 1, 2.
Obtain thyroid function tests (TSH, free T4, free T3) as part of the evaluation, since low energy states cause decreased total T3, free T3, and free T4, as recommended by the Endocrine Society 1, 2.

Complete iron panel: serum iron, transferrin saturation, C-reactive protein, as recommended by the European Society for Clinical Nutrition and Metabolism 3.
Complete blood count with reticulocyte count and red cell indices, as stated by the American Society of Hematology 3.
Thyroid function tests: TSH, free T4, free T3, as recommended by the Endocrine Society 1, 2.
Comprehensive metabolic panel to assess for other metabolic derangements, as indicated by the American College of Sports Medicine 1.

Relative Energy Deficiency in Daily Life (RED-S) with HPA axis suppression, as reported by the International Society of Sports Nutrition 1, 2.
Anemia of chronic disease rather than true iron deficiency, as stated by the European Crohn’s and Colitis Organisation 5.
Functional hypothalamic amenorrhea from chronic energy restriction, as indicated by the American College of Sports Medicine 1, 2.