Endocrine Abstracts

Ms SV is a 27-year-old woman with a history of attention deficit hyperactivity disorder (ADHD). She was referred to the Endocrine team in October 2023 following an incidental finding of abnormal thyroid function tests. The blood test was done as part of the investigations for her alopecia. Her thyroid stimulating hormone (TSH) was significantly elevated at 241 mU/l, while her Free T4 was low at 1.1 pmol/l. Additionally, she was found to have impaired kidney function with an estimated glomerular filtration rate (eGFR) of 58 ml/min/1.73m², compared to her baseline eGFR of >90 ml/min/1.73m² from 2020. Due to the severe, yet asymptomatic hypothyroidism, Ms SV was started on levothyroxine 50 micrograms once daily by her general practitioner (GP). The dose was subsequently increased to 100 micrograms once daily. Her thyroid peroxidase antibodies were elevated at 53.9 kU/L (normal range: 0-34 kU/l), and her thyroid receptor antibodies were also raised at 3.8 IU/L (normal range: 0 - 0.9 IU/l), confirming a diagnosis of Hashimoto’s thyroiditis. The absence of microalbuminuria suggested that her renal impairment was not due to intrinsic renal disease. As her thyroid function gradually normalised, her kidney function also showed improvement, as demonstrated in the table below. This case report highlights a rare cause of reversible acute kidney injury secondary to severe hypothyroidism, which typically resolves after appropriate treatment of the hypothyroidism. In this case, the full recovery of kidney function can take up to 10 months. By recognising the connection between severe hypothyroidism and acute kidney injury, unnecessary invasive investigations for kidney impairment can be deferred until the hypothyroidism is treated.