Background: The underlying risk factors for young-onset cryptogenic ischaemic stroke (CIS) remain unclear. This multicentre study aimed to explore the association between heavy alcohol consumption and CIS with subgroup analyses stratified by sex and age.

Methods: Altogether, 540 patients aged 18-49 years (median age 41; 47.2% women) with a recent CIS and 540 sex-matched and age-matched stroke-free controls were included. Heavy alcohol consumption was defined as >7 (women) and >14 (men) units per week or at least an average of two times per month ≥5 (women) and ≥7 (men) units per instance (binge drinking). A conditional logistic regression adjusting for age, sex, education, hypertension, cardiovascular diseases, diabetes, hypercholesterolaemia, current smoking, obesity, diet and physical inactivity was used to assess the independent association between alcohol consumption and CIS.

Results: Patients were twice as more often heavy alcohol users compared with controls (13.7% vs 6.7%, p<0.001), were more likely to have hypertension and they were more often current smokers, overweight and physically inactive. In the entire study population, heavy alcohol consumption was independently associated with CIS (adjusted OR 2.11; 95% CI 1.22 to 3.63). In sex-specific analysis, heavy alcohol consumption was associated with CIS in men (2.72; 95% CI 1.25 to 5.92), but not in women (1.56; 95% CI 0.71 to 3.41). When exploring the association with binge drinking alone, a significant association was shown in the entire cohort (2.43; 95% CI 1.31 to 4.53) and in men (3.36; 95% CI 1.44 to 7.84), but not in women.

Conclusions: Heavy alcohol consumption, particularly binge drinking, appears to be an independent risk factor in young men with CIS.