Endocrine Abstracts

Background: ACTH concentrations remain typically elevated in patients with Addison’s disease. We present a case of an extremely potent oral contraceptive pill (OCP) induced increase in total cortisol resulting in inhibition of ACTH secretion that was normalized on OCP withdrawal.

Case Presentation: A 20-year old female was diagnosed with Addison’s disease [cortisol 1.59 µg/dl, ACTH>500 pg/ml (0-65)] and started on hydrocortisone. Few months later an OCP (Yasmin®) was added. She still felt unwell, so further tests were performed. Her cortisol day curve (hydrocortisone 15 mg (8 am) + 10 mg (15.00)) showed several cortisol concentrations above upper assay detection limit [e.g. cortisol 8:00 (pre-dose) 3.0 µg/dl, 10:00>63,44 µg/dl] with low ACTH concentrations [e.g. ACTH 8:00 (pre-dose) 24.1 pg/ml; 10:00 - 3.8 pg/ml]. Even 5 mg hydrocortisone induced a massive increase in cortisol [cortisol pre-dose: 1.7 µg/dl, post-dose 30min. >63.44 µg/dl, 60min. >63.44 µg/dl]. CRH test showed stimulation of ACTH far below concentrations observed in Addison’s disease, suggestive of partial hypothalamic suppression of CRH release: ACTH -15min. 42.4 pg/ml, 0min. 44.5 pg/ml, 15min. 63.3 pg/ml, 30min. 87.3 pg/ml, 60min. 76.3 pg/ml, 90min. 58.0 pg/ml, cortisol concentrations <2.5 mg/dl at all time-points. Withdrawal of an OCP resulted in normalisation of ACTH secretion with ACTH concentrations typical for patients with Addison’s disease on hydrocortisone replacement: e.g. cortisol 8.00 <0.054 [ug/dl], ACTH 924.7 [pg/ml], cortisol 10:00 7.3 µg/dl, ACTH 10:00 181.6 pg/ml.

Conclusions: Effects on an OCP on total cortisol concentrations are often underestimated, as an OCP-induced increase in total cortisol can inhibit CRH and ACTH release even in patients with Addison’s disease. An assessment of an adrenocorticotropic axis may be invalidated if a patient is taking an oral contraceptive pill.