HDL biology
CETP activity rises in hyperthyroidism and falls in hypothyroidism, tracking free T4, though hepatic lipase drives the HDL2 changes (J Clin Endocrinol Metab 1998)
Original title: Effect of thyroid dysfunction on high-density lipoprotein subfraction metabolism: roles of hepatic lipase and cholesteryl ester transfer protein
To investigate the effect of thyroid dysfunction on HDL metabolism, HDL subfractions, apoA-I-containing particles, and remodeling enzyme activities were measured in 18 hyperthyroid and 17 hypothyroid patients before and after treatment, compared with euthyroid controls. HDL2 cholesterol and LpA-I were reduced in hyperthyroidism (P < 0.01 and P < 0.05) and increased in hypothyroidism (both P < 0.05). Hepatic lipase and CETP activities were elevated in hyperthyroidism and reduced in hypothyroidism (P < 0.05 for hepatic lipase; P < 0.05 and P < 0.01 for CETP), and both were related to free T4 levels. Changes in HDL2 cholesterol and LpA-I correlated with changes in hepatic lipase after treatment, but not with CETP or lipoprotein lipase. The authors conclude thyroid hormone effects on HDL are mediated mainly through hepatic lipase activity.
Original abstract
To investigate the effect of thyroid dysfunction on high-density lipoprotein (HDL) metabolism, we measured HDL subfractions, apolipoprotein A-I containing particles (LpA-I and LpA-I:A-II), and the activities of enzymes involved in the remodeling and metabolism of HDL [namely hepatic lipase (HL), lipoprotein lipase, and cholesteryl ester transfer protein (CETP)] in 18 hyperthyroid and 17 hypothyroid patients before and after treatment. HDL was subfractionated by density gradient ultracentrifugation, and LpA-I was analyzed by electroimmunodiffusion. The major changes were found in the HDL2 subfraction and in LpA-I particles. HDL2-C and LpA-I were reduced in hyperthyroidism (P < 0.01, P < 0.05, respectively) and increased in hypothyroidism (both P < 0.05) compared with their respective euthyroid matched controls. Changes in HDL2-cholesterol were reversed after treatment in both hyper- and hypothyroid patients, and LpA-I also decreased in the hypothyroid patients after treatment. HL (P < 0.05) and CETP activities (P < 0.05) were elevated in hyperthyroidism and reduced in hypothyroidism (P < 0.05, P < 0.01 respectively) and both were related to free T4 levels. The changes in HDL2-C and LpA-I correlated significantly with changes in HL after treatment but not with CETP or lipoprotein lipase. In summary, HDL metabolism was altered in thyroid dysfunction, and the effect of thyroid hormone on HDL was mediated mainly via its effect on HL activity.
Summary written by cetpinhibition.org from the published abstract; figures as published. Page updated 19 August 2026. Methods.