Cholesterol Too Low Boosts Risk of Hemorrhagic Stroke

A new study reveals that patients with low-density lipoprotein (LDL) cholesterol levels below 70 mg/dL have a higher risk of hemorrhagic stroke.

Researchers at Pennsylvania State University (Hershey, USA), Kailuan General Hospital (Tangshan, China), and other institutions conducted a prospective study involving 96,043 participants who were free of stroke, myocardial infarction (MI), and cancer at baseline to prospectively examine the association between LDL concentrations and intracerebral hemorrhage (ICH) risk. Serum LDL concentrations were assessed in 2006, 2008, 2010, and 2012, and incident ICH was confirmed by review of medical records.

In all, the researchers identified 753 incident ICH cases during nine years of follow-up. The ICH risk was similar among participants with LDL concentrations of 70-99 mg/dL and higher. In contrast, participants with LDL-C concentrations lower 70 mg/dL had a significantly higher risk of developing ICH, with an adjusted hazard ratio of 1.65 for LDL concentrations of 50-69 mg/dL, and 2.69 for LDL concentrations lower than 50 mg/dL. The findings remained consistent after controlling for age, sex, blood pressure, and medication. The study was published on July 2, 2019, in Neurology.

“As is true with many things in nutrition, moderation and balance is key when deciding the optimal target level of LDL cholesterol. And if you're at a high risk for hemorrhagic stroke due to family history or risk factors like high blood pressure and heavy alcohol drinking, you may want to be extra careful about LDL cholesterol levels,” said senior author Xiang Gao, PHD. “These data can help determination of the ideal LDL range in patients who are at increased risk of both atherosclerotic disease and hemorrhagic stroke, and guide planning of future lipid-lowering studies.”

LDL is one of the five major groups of lipoproteins, which enable transport of lipids such as cholesterol and triglycerides within the bloodstream. LDL particles also transport cholesterol into the artery wall, where it is retained by arterial proteoglycans, attracting macrophages and encouraging the formation of atherosclerotic plaques. Over time the vulnerable plaques rupture, activate blood clotting factors and producing arterial stenosis, which if severe enough results in heart attack, stroke, peripheral vascular disease symptoms, and major debilitating events.

Related Links:
Pennsylvania State University
Kailuan General Hospital