Background and purpose: Although it has been reported that the amount of alcohol consumption has a J-shaped association with ischemic stroke, it is unclear whether differences in drinking patterns affect this relationship. We aimed to clarify the impact of drinking patterns on ischemic stroke in midlife.
Methods: We used data from the National Health Insurance Service-National Sample Cohort, which is a large-sized, standardized population cohort in Korea. Five different drinking patterns were defined by combining the frequency of alcohol consumption and quantity of alcohol consumed per occasion, that is, abstainers, not drinking alcohol; drinker group I, ≤30 g/d and <5 d/wk; drinker group II, ≤30 g/d and ≥5 d/wk; drinker group III, >30 g/d and <5 d/wk; and drinker group IV, >30 g/d and ≥5 d/wk. The association between the drinking patterns and ischemic stroke occurrence was analyzed using the Cox proportional hazard model.
Results: A total of 152 469 middle-aged participants (mean age, 50.2 years; 72 285 men [47.4%]) were eligible for the analyses. The median follow-up time was 9.0 years. Compared with abstainers, those who drank <5 d/wk (drinker groups I and III) had a significantly lower risk of ischemic stroke (group I hazard ratio, 0.71 [95% CI, 0.59-0.85]; group III hazard ratio, 0.80 [95% CI, 0.68-0.93]) during the first 7 years from the baseline, while other drinker groups showed no such differences. However, the effect of drinking patterns on ischemic stroke risk was attenuated after the first 7 years.
Conclusions: Reduced risk of ischemic stroke was observed in middle-aged participants with specific drinking patterns, but it was limited to the earlier period. Physicians should be cautious in educating patients on alcohol consumption, considering the long-term association between drinking patterns and ischemic stroke.
Keywords: alcohol drinking; cerebral infarction; drinking behavior; stroke.