A 52-year-old woman with a history of obesity and hypothyroidism saw her primary care provider (PCP), complaining of fatigue and a 30 pound (14 kg) weight gain over 3 months.
Student Discussion Document (pdf)
Lu Song, Laura Y. Sue, and Anthony P. Heaney
A 52-year-old woman with a history of obesity and hypothyroidism saw her primary care provider (PCP), complaining of fatigue and a 30 pound (14 kg) weight gain over 3 months. Her body mass index was 45 kg/m2 and she had recently become hypertensive (blood pressure 136/83 mmHg). The PCP checked her early morning serum cortisol level and, surprisingly, it was low at 0.5 μg/dL (13.8 nmol/L) (reference interval [RI]: 4 to 225 μg/dL, 110 to 6208 nmol/L). Her hypothyroidism was well controlled on a stable dose of levothyroxine 50 μg daily. In light of the low morning cortisol level, she was referred to a community endocrinologist who noted her rounded facial appearance and redness on her cheeks. The patient reported facial hair growth, easy bruising, and striae on her legs. On repeated questioning, she denied any use of steroids. Repeat early morning serum cortisol on several occasions was 0.5 μg/dL (13.8 nmol/L) with suppressed plasma adrenocorticotropic hormone (ACTH) levels of <5 pg/mL (<1.1 pmol/L) (RI, 6 to 50 pg/mL, 1.32 to 11 pmol/L). Other serum pituitary hormone levels, as well as estradiol, dehydroepiandrosterone (DHEA) sulfate, and a comprehensive metabolic panel were all within the RIs.