Too Low "bad Cholesterol" Levels Linked To Risk Of Cerebral Hemorrhage

Too low "bad cholesterol" levels linked to risk of cerebral hemorrhage

The high level of low density lipoprotein ("bad cholesterol") in the blood has long been known as a factor in cardiovascular disease. In a new study, researchers found that too little of it is also dangerous: in women, it is associated with an increased likelihood of hemorrhagic stroke.

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It is known that low-density lipoprotein (LDL) cholesterol levels below 100 mg / dL reduce the risk of myocardial infarction and stroke. However, a new study found that women who have levels that are too low (70 mg / dL or less) more than 2 times more likely to have hemorrhagic stroke compared with women who have levels slightly higher than normal. The study is published in the online issue of Neurology, the medical journal of the American Academy of Neurology.

Hemorrhagic strokes (hemorrhages) are much less common than ischemic strokes (insufficient blood supply to a particular part of the brain); they are more difficult to treat, therefore the likelihood of death is higher.

“Strategies to lower cholesterol and triglyceride levels, such as dietary changes or statins, are widely used to prevent cardiovascular disease. But our large study shows that very low levels in women may carry some risks as well. Women already have a higher risk of stroke than men, in part because they live longer, so it is important to be clear about ways to reduce their risk,”said study author Pamela Rist, assistant professor at Harvard Medical School. School), Boston, and a member of the American Academy of Neurology.

The participants in the study (27,937 women aged 45 years and older) measured the levels of cholesterol - total, LDL, HDL (high density lipoprotein, so called "good") and triglycerides (blood fat). Over 19 years (on average) follow-up, according to medical records, 137 women suffered strokes.

For example, 9 out of 1069 women (0.8%) with cholesterol of 70 mg / dL or less had a stroke, compared with 40 out of 10,067 (0.4%) women with cholesterol of 100-130 mg / dL. After adjusting for other risk factors (age, smoking status, high blood pressure, and statin treatment), the researchers determined that patients with very low LDL cholesterol were 2.2 times more likely to have hemorrhagic stroke.

Based on triglyceride levels (fasting), the researchers divided the women into four groups (lowest and highest):

74 mg / dL or less

• 85 mg / dL or less
• above 156 mg / dl,
• above 188 mg / dl.

The researchers found that 34 out of 5,714 women (0.6%) had strokes with the lowest triglyceride levels, compared with 29 out of 7,989 women (0.4%) with the highest triglyceride levels. Adjusted for other risk factors, the likelihood of hemorrhage at the lowest triglyceride level was 2 times higher.

“Women with very low LDL cholesterol or low triglycerides should be checked by doctors for other risk factors for stroke that can be changed, such as high blood pressure and smoking, to reduce the risk of hemorrhagic stroke. In addition, more research is needed to determine how to reduce the risk of hemorrhagic stroke in women with very low LDL cholesterol and low triglyceride levels,”said Pamela Rist.

However, the study has limitations. First, the measurements were taken once, and second, the majority of women had reached menopause at the time of the measurements, which made it difficult for researchers to figure out if menopause might have an impact.