A High Hematocrit May Increase the Risk of Heart Failure

If you have a high hematocrit, you may be at greater risk for heart failure. According to new research, men and women with hematocrit levels at the high end of normal may be at risk for heart problems.

High Hematocrit Count: Does It Increase the Risk of Heart Failure?

When researchers looked at hematocrit levels in 3,523 healthy people between the ages of 50 and 65 as part of the Framingham Heart Study, they found a linear relationship between hematocrit level and their risk of heart failure.

Those with a high-normal hematocrit had twice the risk of developing heart failure relative to those with a low hematocrit level. Women with a hematocrit count greater than 46% and men with a level greater than 50% were at higher risk for heart failure irrespective of other factors. The higher risk of heart failure among those with a high hematocrit or high-normal reading held true even after researchers controlled for other factors that could affect heart failure risk.

Why Would a High Hematocrit Level Be Linked With Heart Failure?

Researchers don't know for sure why high hematocrit levels and heart failure are linked. One theory is that a high-normal hematocrit reduces the ability of blood vessels to expand. This would put additional strain on the heart and increase the risk of heart failure. A high hematocrit also increases the viscosity of the blood, which means the heart has to work harder to pump the thicker blood through the body.

More research is needed to find out whether this association holds true in larger populations. The limitation of this study was that it included a large number of smokers, which researchers adjusted for, but it still isn't representative of the average population.

If these results hold true in future studies, it's possible that doctors will recommend that people with high-normal hematocrit levels donate blood to bring it down. Quitting smoking will also help reduce high hematocrit levels. Some people have elevated hematocrit levels due to dehydration, so drinking more water may help.

The Bottom Line?

If you have a high hematocrit, talk to your doctor. Certain medical conditions can cause hematocrit levels to be high including polycythemia vera and chronic lung disease - and it's important to treat these conditions if you have them.

References:

Family Practice News. February 1, 2011. page 22.