Dyslipidemia is a common finding in patients with thyroid disease, explained by 
the adverse effects of thyroid hormones in almost all steps of lipid metabolism. 
Not only overt but also subclinical hypo- and hyperthyroidism, through different 
mechanisms, are associated with lipid alterations, mainly concerning total and 
LDL cholesterol and less often HDL cholesterol, triglycerides, lipoprotein (a), 
apolipoprotein A1, and apolipoprotein B. In addition to quantitative, 
qualitative alterations of lipids have been also reported, including atherogenic 
and oxidized LDL and HDL particles. In thyroid disease, dyslipidemia coexists 
with various metabolic abnormalities and induce insulin resistance and oxidative 
stress via a vice-vicious cycle. The above associations in combination with the 
thyroid hormone induced hemodynamic alterations, might explain the increased 
risk of coronary artery disease, cerebral ischemia risk, and angina pectoris in 
older, and possibly ischemic stroke in younger patients with overt or 
subclinical hyperthyroidism.