CureusProfound Hypothyroidism as a Reversible Cause of Severe Low-Density Lipoprotein Cholesterol (LDL-C) Elevation: A Case Report

⚠️ Small Study / Early Comparative Evidence

A case report described recurrent severe LDL-C elevations during periods of profound hypothyroidism in a post-thyroidectomy patient. LDL-C improved after restoration of euthyroidism, without documented lipid-lowering therapy.

Clinical Considerations

• LDL-C peaked at 259 mg/dL during severe recurrent hypothyroidism, alongside elevated TSH and ApoB.
• LDL-C fell to 110 mg/dL after improved levothyroxine adherence restored euthyroidism.
• Calcium separation requirements and medication burden complicated long-term levothyroxine replacement.
• Dynamic LDL-C changes argued against assuming primary familial hypercholesterolemia without secondary-cause review.

Practice Applications

• Recognize uncontrolled hypothyroidism as a reversible contributor to severe LDL-C elevation.
• Review levothyroxine timing, calcium separation, and adherence barriers.
• Interpret LDL-C escalation within thyroid-function and medication-history context.
• Avoid premature lipid-therapy escalation when reversible secondary causes remain unresolved.