LDL Cholesterol-How Low Can We Go?

Combinations of lipid-lowering agents can often bring LDL cholesterol down to around 40 mg/dL (1 mmol/L). Randomized controlled trials indicate that this reduces the risk of atherosclerotic vascular events with minimal adverse effects. This has raised the question of whether there is any concentration of LDL cholesterol below which further lowering is futile and/or a source of new adverse effects. This article examines several lines of evidence that lead to the conclusion that there is no known threshold below which lowering LDL cholesterol is harmful, but reduction of LDL cholesterol below 25 mg/dL may provide little if any further benefit.