Fibrinogen is a soluble protein in the plasma that is broken down to fibrin by the enzyme thrombin to form clots.fibrinogen, also known as factor I, is a plasma protein that can be transformed by thrombin into a fibrin gel “the clot”. Fibrinogen is synthesized in the liver and circulates in the plasma as a disulfide-bonded dimer of 3 subunit chains.
Fibrinogen is one of 12 blood clotting factors in the human body. Fibrinogen proteins are soluble proteins that get converted to fibrin, an insoluble protein. The presence of elevated fibrinogen in blood plasma indicates acute and/or chronic inflammation in various parts of the body, most notably, in the cardiovascular system. Fibrinogen appears as a result of inflammation and is a predictor of CVD severity. Endothelial cells line the entire structure of the innermost parts of arteries, veins, and capillaries. The Tunica Intima made up of endothelial cells, and the Tunica Media comprised of smooth muscle, line the entire inside structure of arteries and veins. The thickness of the Tunica Intima and the Tunica Media of the carotid artery (Intima-Media Thickness-CIMT) are reliable indicators of the presence and severity of CVD. Chronic high plasma fibrinogen levels have a strong relationship with the severity of CIMT. Fibrinogen levels also rise in the acute phase of postischemic stroke. Fibrinogen levels that continue to rise in post ischemic stroke result in a poor prognosis. Therefore, fibrinogen testing is done when CVD is suspected and when a cardiovascular incident has occurred. However, fibrinogen testing can also be an early predictor of future CVD. Evidence suggests that fibrinogen levels begin to rise many months, even years before the cardiovascular disease is fully present as part of the slow progressive clotting pathophysiology associated with vascular diseases. The presence of fibrinogen levels in ages 27 to 35 has been singularly linked to CIMT. Fibrinogen and CRP are both proteins that makeup plaque. The CRP test is a sensitive test for inflammation and is more predictive of cardiovascular risk than fibrinogen as suggested by many research papers. Therefore, CRP is the test primarily given to patients. Fibrinogen is part of the clotting factor and there is growing evidence suggesting that its presence is equally as revealing as the CRP. Combining the CRP and the fibrinogen test results in what is called CRP/Fibrinogen ratio, which has been shown to be more sensitive and a better predictor of CVD risk that each of these test used alone because of their higher level of sensitivity in detecting Disseminating Intravascular Coagulation (DIV), a condition where fibrin ultimately causes excessive clots leading to multiple organ failure CRP and Fibrinogen levels rise in the following conditions:
- tissue damage/trauma,
- Strokes and Heart attack
- inflammatory diseases.
Fibrinogen tests are often used after a cardiovascular incident has occurred or if symptoms are severe enough to warrant a test. However, there is sufficient evidence which shows that fibrinogen levels slowly begin to rise long before a heart attack or stroke and may even be reflective of the severity of subclinical atherosclerotic conditions. Preventative and Functional Medicine have treatments which reduce or normalize Fibrinogen levels, thereby, preventing the progression of symptoms that can lead to more serious cardiovascular occurrences in the future.