High C-Reactive Protein Levels May Double Stroke Risk, Study Finds

The UK Biobank study found that increasing or consistently elevated CRP levels were linked to a higher risk of stroke. Elevated CRP was associated with a 44% increased risk of any stroke and a 65% greater likelihood of ischemic stroke. The highest risk was observed in individuals with persistently high CRP, nearly doubling their chances of hemorrhagic stroke. Genetic analysis further confirmed CRP’s significant connection to stroke risk.

Stroke affects one in four individuals worldwide, ranking as the second leading cause of death and a major contributor to disability. Ischemic strokes account for about 80% of cases. Inflammation plays a key role in stroke risk, with CRP serving as a recognized biomarker. While most studies focus on single CRP measurements, variations over time may offer better risk assessment. Genetic factors also influence stroke susceptibility, yet no research has fully explored the genome-wide link between CRP changes and stroke risk. Understanding these connections could improve stroke prediction and prevention strategies.

Against the above background, Jun Lyu, Department of Clinical Research Jinan University First Affiliated Hospital Guangzhou, Guangdong, China, and colleagues sought to investigate the relationship between changes in CRP levels and the risk of stroke and its subtypes.

For this purpose, the researchers analyzed UK Biobank data to explore the link between CRP changes and stroke risk using Cox proportional hazards regression. They further conducted genetic analyses, including genetic correlation, pairwise genome-wide association studies, and polygenic risk scores. The study included 14,754 participants with a median follow-up of 10.4 years.

The study led to the following findings:

• Participants with an increased CRP percentage had a higher risk of any stroke (HR 1.44) and ischemic stroke (HR 1.65).
• Those whose CRP levels became high had an increased risk of any stroke (HR 1.45), while those with persistently high CRP faced the greatest risk (HR 1.74).
• Similar trends were observed for ischemic stroke.
• Persistently high CRP levels were also linked to a greater risk of hemorrhagic stroke (HR 1.91).
• Genetic analysis revealed a significant genetic correlation between CRP and stroke.
• Five shared genomic regions between CRP and stroke were identified.
• Individuals with both high stroke polygenic risk scores and elevated or persistently high CRP levels had the highest stroke risk.

This study highlights the association between CRP changes and stroke risk, showing that elevated or persistently high CRP levels increase the likelihood of any stroke and ischemic stroke. In contrast, hemorrhagic stroke is linked only to sustained high CRP levels. Genetic analyses further revealed shared biological pathways between CRP and stroke, identifying five common genomic regions. Individuals with both high stroke polygenic risk scores and elevated or persistent CRP levels faced the greatest stroke risk.

"These findings emphasize the importance of monitoring CRP changes over time for improved stroke risk assessment and may inform future prevention strategies," the authors concluded.

Reference: https://doi.org/10.1161/JAHA.124.03808