Elevated CRP Has Robust Link to Higher A-Fib Risk
But genetically elevated CRP not linked, suggesting high CRP per se doesn't raise risk
WEDNESDAY, Aug. 25 (HealthDay News) -- Higher levels of plasma C-reactive protein (CRP) are robustly associated with a higher risk of atrial fibrillation, but elevated levels don't necessarily increase the risk, according to research published in the Aug. 31 issue of the Journal of the American College of Cardiology.
Sarah C.W. Marott, M.D., of the Copenhagen University Hospital in Herlev, Denmark, and colleagues analyzed data from 46,876 individuals. Participants underwent high-sensitivity CRP assessment and were genotyped for four CRP gene polymorphisms.
The researchers found that CRP level in the upper versus lower quintile was associated with a 2.19-fold higher risk of atrial fibrillation. After adjustment for multiple factors, the risk was attenuated to 1.77, and with additional adjustment for heart failure and plasma fibrinogen level, it was 1.47 and 1.63, respectively. However, genotype combinations of the polymorphisms were associated with up to 63 percent higher plasma CRP levels, but weren't linked to higher risk of atrial fibrillation. The authors concluded that although elevated CRP had a robust association with higher atrial fibrillation risk, genetically elevated CRP levels do not, which suggests that elevated plasma CRP per se does not cause increased atrial fibrillation risk.
"Ascertainment and classification of atrial fibrillation is a potential limitation of the present study because atrial fibrillation may have occurred in some individuals without having been diagnosed, because atrial fibrillation may have been coded incorrectly in the national Danish Patient Registry, or because some individuals might not have had atrial fibrillation at one of the follow-up examinations, that is, if they had paroxystic atrial fibrillation," the authors write.