In a new study, led by researchers at the University of Limerick Graduate Entry Medical School, high levels of plasma "fibrinogen" - a clotting factor that can be measured in the blood stream - were associated with higher death rates in patients with kidney disease. The study evaluated data of 9,184 US adults, age 40 and over who were followed for up to 15 years as part of the US-based Third National Health and Nutrition Examination Survey (NHANES III). The UL research team found that even a small rise in blood fibrinogen levels (1 µmol/L increase) led to increased risk of death (7%) and that figure rises to over 50% when the levels rose beyond 10.5 µmol/L.
According to primary author, Professor Austin Stack MD, Foundation Chair of Medicine at University of Limerick Graduate Entry Medical School, and Consultant Nephrologist at University Hospital Limerick, "This study is significant as it is the first time evidence has shown that fibrinogen levels can be used to predict future heart attacks, strokes and premature death in patients who have pre-existing kidney disease."
The findings have important implications according to Professor Stack. "At least 1 in 10 people suffer from chronic kidney disease in Ireland. It is becoming increasingly obvious that traditional risk factors such as raised blood pressure, smoking and diabetes do not completely explain the high death rates that are found in patients with chronic kidney disease. Many scientists believe that novel cardiovascular risk factors may contribute to excess deaths in this high risk population. Although plasma fibrinogen levels are not measured routinely in clinical practice, there is an increasing body of evidence to suggest that fibrinogen may damage blood vessels and lead to atherosclerosis. Our study found significantly higher levels among patients with abnormal kidney function compared to those without."
"When we looked at the relationship between fibrinogen levels and cardiovascular deaths, we found that higher levels of fibrinogen were directly associated with higher death rates and the pattern was similar for subjects with normal and abnormal kidney function" according to Professor Ailish Hannigan PhD and senior author of the study. "The relationship between fibrinogen and premature death was still evident after accounting for traditional cardiovascular risk factors".
This study suggests that renewed attention be given to the potential importance of fibrinogen as a cardiovascular risk factor in patients with kidney impairment and calls for definitive randomised controlled clinical trials to evaluate the efficacy of potential treatments.
Professor Stack added; "This simple blood test could help in the earlier identification of high-risk patients with kidney disease in order to prevent major complications."