Endocrine Abstracts

Introduction: Osteoporosis can be associated with Cushing syndrome or hyperthyroidism but is an unusual finding in a patient with primary adrenal insufficiency (with physiological dose of steroid replacement) and concurrent autoimmune hypothyroidism without any other secondary causes of osteoporosis. We present a case of severe osteoporosis in a postmenopausal female in whom we could not establish a verifiable cause.

Case: A 60-year-old postmenopausal woman, previously fit and well and no past medical history of significance, not on any regular medications, initially diagnosed with autoimmune hypothyroidism but levothyroxine replacement resulted in further worsening of her symptoms mainly tiredness, lightheadedness and dizziness which prompted further screening of autoimmune adrenal insufficiency and physiological doses of hydrocortisone and fludrocortisone were initiated resulting in complete resolution of her symptoms remaining clinically well for the following 6-7 months. Beacuse of ongoing back pain and normal MRI lumbosacral spine, we did bone densitometry scan revealing severe osteoporosis with total hip T score of -3.5, lumbar spine -4.5 and femoral neck -2.9. There was no history of eating disorder, malabsorption or premature ovarian failure. She was not on any medications to cause severe osteoporosis except physiological doses of steroids (hydrocortisone 10 mg a.m., 5 mg lunchtime and 5 mg teatime). She was a non-smoker, no alcohol excess and no family history of osteoporosis or fragile fractures. All her secondary workup for osteoporosis were normal including renal functions, liver functions, bone profile, vitamin D, pituitary profile and coeliac screen. Osteoporosis was treated with weekly bisphosphonate resulting in improvement in her bone densitometry scan.

Conclusion: • Autoimmune adrenal insufficiency and autoimmune hypothyroidism can coexist as part of autoimmune polyendocrinopathy but it is extremely important to replace steroids first as patient can clinically deteriorate and levothyroxine replacement before steroids can lead to Addisonian crisis.• It is well established that Cushing syndrome or hyperthyroidism can lead to osteoporosis but it remains unclear if there is any association of adrenal insufficiency and hypothyroidism with osteoporosis.