Nephrotic Syndrome as a Cause of Transient Clinical Hypothyroidism

• Main Authors: Vânia Benido Silva, Maria Teresa Pereira, Carla Leal Moreira, Sílvia Santos Monteiro, Isabel Inácio, Maria Helena Cardoso
• Format: Article
• Language: English
• Published: Hindawi Limited 2021-01-01
• Series: Case Reports in Endocrinology
• Online Access: http://dx.doi.org/10.1155/2021/5523929

Nephrotic syndrome may trigger the onset of hypothyroidism, promoting massive urinary protein losses including thyroxine (T4) and triiodothyronine (T3) along with their binding proteins. At an early stage, a clinical and biochemical euthyroid state is expected. However, in patients with prolonged and severe proteinuria, especially with concomitant low thyroid reserve, urinary losses of free and protein-bound thyroid hormones are sufficiently pronounced to induce a subclinical or overt hypothyroidism. Despite its high prevalence in clinical practice, the literature lacks case reports of newly diagnosed clinical hypothyroidism due to NS in adults, making this condition under-recognized. We report a case of a 23-year-old man with previous normal thyroid function who developed overt hypothyroidism due to a severe nephrotic syndrome, requiring supplementation with levothyroxine (LT). After the patient had undergone bilateral nephrectomy, treatment with LT was discontinued and thyroid function normalized.