Severe LDL-C Elevations Reversed by Restoring Thyroid Hormone in a Post-Thyroidectomy Patient

A 47-year-old woman with autoimmune Hashimoto’s thyroiditis who had total thyroidectomy showed dramatic LDL-C elevations during profound hypothyroidism, driven by reduced LDL receptor activity and increased PCSK9; LDL-C levels improved markedly when euthyroidism was restored with levothyroxine. The case highlights hypothyroidism as a reversible, non-genetic cause of severe hypercholesterolemia and emphasizes evaluating thyroid function before diagnosing familial hypercholesterolemia or initiating lipid-lowering therapy.