The relationship between cholesterolemia and thyroid function is generally described as:

• A. Direct
• B. Inverse
• C. No Relationship
• D. Cyclical

Answer: (B)

Thyroid hormones regulate lipid metabolism, so cholesterol levels tend to move in the opposite direction of thyroid activity. When thyroid function is adequate or high, the liver increases LDL receptor expression and other pathways that clear LDL and convert cholesterol to bile acids, leading to lower circulating cholesterol. When thyroid function is low (hypothyroidism), LDL receptor activity drops, clearance of LDL decreases, and cholesterol builds up in the blood. That inverse relationship explains why hypothyroidism often presents with high cholesterol and why treating it can improve lipid levels. The other patterns don’t fit the biology: a direct relationship would mean higher thyroid activity raises cholesterol (not observed); no relationship ignores the clear impact thyroid status has on lipids; cyclical isn’t the typical description of this link.