Lipid and lipoprotein pattern in thyroid dysfunction and the effect of therapy

Area of Science:

• Endocrinology
• Clinical Biochemistry
• Cardiovascular Research

Background:

• Thyroid hormones play a crucial role in regulating lipid metabolism.
• Abnormalities in thyroid function, such as hypothyroidism and hyperthyroidism, are known to affect lipid profiles.
• Understanding these effects is vital for assessing cardiovascular risk.

Purpose of the Study:

• To investigate the impact of hypothyroidism and hyperthyroidism on lipid and lipoprotein concentrations.
• To compare lipoprotein profiles in hypothyroid, hyperthyroid, and euthyroid individuals.
• To evaluate the effects of therapy on these lipid alterations.

Main Methods:

• Lipid and lipoprotein concentrations, including high-density lipoprotein (HDL) sub-fractions, were measured.
• Subjects included 12 hypothyroid, 11 hyperthyroid, and 27 control female participants.
• Preparative ultracentrifugation was used for lipoprotein isolation, followed by cholesterol and protein content determination.

Main Results:

• Hypothyroid patients exhibited elevated total cholesterol and HDL cholesterol, with a lower LDL-c/HDL-c ratio compared to controls.
• Hyperthyroid patients showed significantly lower total cholesterol and reduced LDL and HDL cholesterol, with increased VLDL.
• Therapy to restore euthyroid state reversed most observed lipid and lipoprotein changes.

Conclusions:

• Thyroid function profoundly influences lipoprotein concentration and composition.
• The altered HDL concentrations in hypothyroidism may impact arteriosclerosis risk.
• Therapeutic correction of thyroid dysfunction partially normalizes lipid abnormalities, with complete normalization potentially linked to therapy duration.