Effect of thyroid function on concentrations of lipoprotein(a)

Area of Science:

• Endocrinology and Metabolism
• Cardiovascular Research
• Lipidology

Background:

• Thyroid hormones regulate numerous metabolic processes, including lipid metabolism.
• Lipoprotein(a) [Lp(a)] is an independent risk factor for cardiovascular disease.
• The precise relationship between thyroid dysfunction and Lp(a) concentrations requires further elucidation.

Observation:

• In 60 patients with thyroid dysfunction, active hyperthyroidism showed a 60% increase in mean Lp(a) levels (73 to 102 mg/L, P < 0.002).
• Conversely, hypothyroidism demonstrated a 10% decrease in mean Lp(a) levels (136 to 114 mg/L, P < 0.02).
• Changes in Lp(a) correlated with low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apo B) during thyroid state normalization.

Findings:

• Treatment of hyperthyroidism led to significant increases in Lp(a), LDL-C, and apo B.
• Treatment of hypothyroidism resulted in significant decreases in Lp(a), LDL-C, and apo B.
• No association between Lp(a) and LDL-C or apo B was observed in the euthyroid state, suggesting thyroid hormones directly influence Lp(a) synthesis.

Implications:

• Thyroid hormone status directly affects Lp(a) concentrations, independent of LDL-C receptor activity.
• These findings highlight a novel mechanism linking thyroid function to cardiovascular risk via Lp(a) modulation.
• Further research may explore therapeutic strategies targeting thyroid hormones to manage Lp(a) levels and cardiovascular risk.