Background and purpose: Previous observational studies have shown a moderately increased risk of intracerebral hemorrhage (ICH) with high self-reported alcohol consumption. However, self-reported data tend to underestimate alcohol consumption. Phosphatidylethanol is a specific biomarker reflecting alcohol intake during the last month and correlates with the amount of alcohol consumed. The present study aimed to investigate the association between phosphatidylethanol levels and the risk of future ICH.
Methods: This population-based nested case-referent study was conducted within the Northern Sweden Health and Disease Cohort. At baseline, all participants underwent a health examination, including a questionnaire with questions about alcohol consumption. A blood sample was collected and stored at -80°C, and phosphatidylethanol 16:0/18:1 levels were measured in packed erythrocytes. Cases (n=97) were diagnosed with a first-ever ICH between 1985 and 2007. Two referents (n=180) were matched to each case.
Results: The mean age at baseline was 55 years, 39% of participants were women, and the mean time from blood sampling to ICH was 7.3 years. Only phosphatidylethanol and hypertension remained independently associated with ICH in a multivariable model. Participants with phosphatidylethanol >0.30 μmol/L had an increased risk of ICH compared with those with phosphatidylethanol <0.01 μmol/L (odds ratio, 4.64 [95% CI, 1.49-14.40]).
Conclusions: High blood concentrations of phosphatidylethanol were associated with an increased risk of future ICH. This association was independent of hypertension and other risk factors for ICH. Our findings suggest that phosphatidylethanol, as a marker of alcohol consumption, may be used as a risk marker of future ICH.
Keywords: alcoholic beverages; alcoholism; biomarkers; case-control study; cerebral hemorrhage; intracranial hemorrhages; stroke.