Current guidelines recommend lowering cholesterol for heart disease risk reduction. New findings have indicated that if cholesterol dips too low, it may boost the risk of hemorrhagic stroke.
Over a period of nine years, a Penn State-led study examined the relationship between low-density lipoprotein ( LDL ) cholesterol and hemorrhagic stroke.
The researchers found that participants with LDL cholesterol levels below 70 mg/dL had a higher risk of hemorrhagic stroke.
The results, published in Neurology, may help refine and personalize recommendations for ideal target cholesterol levels.
According to the researchers, low LDL cholesterol is recommended as a way to reduce the risk of a myocardial infarction or ischemic stroke. But previous research has suggested a link between very low LDL cholesterol levels and hemorrhagic stroke.
The aim of new study was to expand the scope of knowledge in this area by investigating the issue prospectively in a large cohort with multiple LDL cholesterol measurements to capture variation over time.
The study has included 96,043 participants with no history of stroke, myocardial infarction or cancer when the study began.
LDL cholesterol levels were measured when the study began and yearly thereafter for nine years.
Reported incidents of hemorrhagic stroke were confirmed by medical records.
The researchers found that participants who had LDL cholesterol levels between 70 and 99 mg/dL had a similar risk of hemorrhagic stroke. But, when LDL cholesterol levels dipped below 70 mg/dL, the risk of hemorrhagic stroke increased significantly.
For example, the risk increased by 169% for participants with LDL levels less than 50mg/dL relative to those with LDL levels between 70 and 99 mg/dL.
These findings were consistent after controlling for age, sex, blood pressure and medication.
Traditionally, an LDL cholesterol level of more than 100 mg/dL had been considered as optimal for the general population and lower in individuals at elevated risk of heart disease.
Researchers observed that the risk of hemorrhagic stroke increased in individuals with LDL cholesterol levels below 70 mg/dL. This observation, if confirmed, has important implications for treatment targets. ( Xagena )
Source: Pennsylvania State University, 2019