Secondary adrenal insufficiency in a patient with Hashimoto thyroiditis and multiple comorbidities

Abstract

Introduction: While Addison`s disease may be thought of when considering autoimmune polyglandular syndrome in patients with Hashimoto Thyroiditis, secondary adrenal insufficiency is an even rarer finding. The diagnosis is further complicated by nonspecific signs and symptoms, such as hyponatraemia or fatigue, that may be attributed to other comorbidities, like heart failure. Materials and methods: A 63-year-old male patient presented with complaints of generalized weakness, weight loss (body mass index 15), lack of appetite and nausea. His medical history was extensive, including Hashimoto thyroiditis and advanced left-sided heart failure with pacemaker placement due to Sick Sinus Syndrome and hypertension stage III, amongst other diagnoses. Results: Initial examinations revealed hypoglycaemia (2.2 mmol/L) and hyponatraemia (118 mEq/L), with no other relevant abnormalities. Once adrenal insufficiency was considered, serum cortisol (46.98 nmol/L) and adrenocorticotropic hormone (7.13 pg/mL) were both found decreased. Synacthen test results were 91.32 nmol/L - 0 min, 281.09 nmol/L - 30 min, 390.3 nmol/L - 60 min, and urine cortisol was 552 mcg/24h. The remaining pituitary hormones were in normal range. Computed tomography (as magnetic resonance was contraindicated) failed to determine the cause and no hypothalamopituitary pathology was observed, although the possibility of a microadenoma could not be excluded. Therapy with methylprednisolone was instituted successfully. Conclusion: The pathophysiology of secondary adrenal insufficiency in this patient was most likely autoimmune. This case report represents an unusual diagnosis, which additionally highlights the various possible effects of adrenocorticotropic hormone deficiency and the complexity of the clinical picture that may be seen in patients with multiple autoimmune endocrine disorders and comorbidities.