Blood Fats and Stroke Risk

Traditionally, when doctors think of stroke and heart disease, they think of the levels of LDL or “bad” cholesterol in the diet and in the bloodstream. Recent research indicates that triglycerides may play a bigger role in getting stroke than does LDL cholesterol. Other cholesterol particles in the blood stream may be better predictors than LDL cholesterol when it comes to getting a stroke.

A recent study looked at 774 US women who had had a stroke over an eight year period of time. Each woman was compared to another stroke free woman who was of the same age and race. As it turned out, women with the highest triglyceride levels were 56 percent more likely to suffer a stroke than those with the lowest triglyceride levels. The link to high triglycerides persisted even when doctors factored in other things like high blood pressure and diabetes.

The American Heart Association already considers elevated triglyceride levels as risk factors for strokes. It’s just now that newer research studies are substantiating it.

Normal triglyceride levels are between 150 and 199 mg/dL. Anyone with a triglyceride level of over 200 mg/dL is considered to have a high level of triglycerides in the bloodstream.

Interestingly, the LDL level in this recent study was not considerably linked to strokes. Instead it was the intermediate-density lipoprotein or IDL. Those who had the most IDL in their bodies seemed to have more strokes by a factor of about 46 percent higher.

The same was true with VLDL or very low density lipoproteins. Women who had more and larger VLDL were at a greater risk of developing a stroke. VLDL is not always reported in standard cholesterol screening.

From this study, it could not be determined the absolute risk of getting a stroke with various LDL levels, triglyceride levels or VLDL levels but it does indicate that there is a relative risk as these fat particles rise in the bloodstream.

The study also suggested that the standard total cholesterol, HDL cholesterol and LDL cholesterol level checking in blood tests might not be enough and the tests should definitely include triglyceride levels and VLDL numbers.

The types of strokes being talked about in these studies are “ischemic strokes”—those caused by blockages of the arteries leading to the brain, rather than “hemorrhagic strokes” which are usually caused by high blood pressure and represent bleeding into the brain.

Testing for these new markers for disease may be helpful for patients in the intermediate range for having a stroke or heart attack. These people would benefit from having cholesterol numbers as well as triglyceride and VLDL numbers so that pharmacological means can be used to help reduce the stroke and heart attack risk in these patients.