Fibrinogen and Fibrates- A New Approach to Preventing Heart Attacks

Coronary angiogram of a man

Coronary arteries

This is revisiting a topic I covered earlier in my post Hypertension Maybe Your Blood’s Too Thick. Basically I reviewed the literature on the topic of viscosity of blood possibly leading to high blood pressure. One key protein that is implicated in thickening the blood is fibrinogen. It is involved in the inflammatory pathways and blood clotting. It seems by research that in normal levels it keeps a good balance of helping the immune system and preventing major bleeding while not causing too many clots or inflammation. But when the level is too high is seems to increase the risk for coronary artery disease leading to heart attacks. A 1999 study Eriksson et al. showed that those in the highest 25% of fibrinogen levels had 3 times the risk for coronary artery disease than those in the lowest 25% even after controlling for other coronary artery disease risk factors. Many other studies have shown the same relationship including Onohara 2000, Bolibar 1993, De Luca 2011, Montalescot 1998, Lima et al 2012, and many more. In fact looking closely at the data fibrinogen is likely a more accurate predictor of risk for heart disease than cholesterol.

So one may ask why isn’t my doctor following my fibrinogen level, and if its high why aren’t they treating it? Well before I would have said because we have no known treatment to lower fibrinogen but then I found data showing this is not true. Multiple studies have shown that the pharmaceutical class of drugs referred to as fibrates do decrease fibriongen. This includes drugs such as fenofibrate and gemfibrozil which are usually used to treat a certain type of cholesterol when it is high called triglycerides. They do this pretty well but studies for outcomes did not show a huge benefit therefore they are not commonly used. However, they have never been tested in patients with high fibrinogen, they have only been studied in patients with high cholesterol or triglycerides. As far back as 1999 de la Serna et al. showed that fenofibrate decreased fibrinogen by 15%. In fact there was a study as far back as 1989 by Leschke et al showing that fenofibrate dropped fibrinogen levels from a mean of 300 to 250. They also showed a significant improvement in blood viscosity and using myocardial scintigraphy (a study to look at blood flow to the heart) they showed an improvement in blood flow to areas of the heart that previously were not getting adequate blood flow in all subjects they evaluated. It was however a small study. This drop in fibrinogen is not seen with statin drugs which are the most commonly used cholesterol drugs today.

And then of course there are the always forgotten and neglected natural medications. A 2009 study by Hsia et al. showed that nattokinase (a supplement derived from fermented soy and commonly used in Japan) can decrease fibrinogen levels by 9%. And a recent rat study May 2013 by El-Sayed et al showed curcumin (the ingredient believed to be the main active ingredient of turmeric) can decrease fibrinogen along with multiple other cardiovascular risk factors as well.

There are many more studies, too many to cite them all. Given the vast amount of data we have and considering that it goes back as far as the 1980s it is way overdue to do a study where we take a group of patients with high fibriongen levels and radomize them to fenofibrate (or another fibrate, or curcumin or nattokinase) and see if they get a significant drop in fibriongen. Then more importantly follow them to see if that translates into a significant decrease in the risk for heart attack and/or stroke. Given that fibrinogen is intricately involved in inflammation and blood clot formation it only seems logical that reducing it would translate into huge health benefits. It’s about time to find out if we should be more concerned about our fibrinogen level than our cholesterol.


Studies showing relationship of fibrinogen to coronary artery disease– Eriksson et all. – Onohara et al. – Bolibar et al.– De Luca et al., Montalescot et al., Lima et al.

Fibrates and fibriongen – de la Serna et al– Leschke et al

Natural supplements and fibrinogen– Hsia et al– El Sayed et al.