Differing association of alcohol consumption with different stroke types: a systematic review and meta analysis
BackgroundWhether light to moderate alcohol consumption is protective against stroke, and whether any association differs by stroke type, is controversial. We conducted a meta analysis to summarize the evidence from prospective studies on alcohol drinking and stroke types.MethodsStudies were identified by searching PubMed to September 1, 2016, and reference lists of retrieved articles. Additional data from 73,587 Swedish adults in two prospective studies were included. Study specific results were combined in a random effects model.ResultsThe meta analysis included 27 prospective studies with data on ischemic stroke (25 studies) intracerebral hemorrhage (11 studies) and/or subarachnoid hemorrhage (11 studies) Light and moderate alcohol consumption was associated with a lower risk of ischemic stroke, whereas high and heavy drinking was associated with an increased risk; the overall RRs were 0.90 (95 CI, 0.85 0.95) for less than 1 drink/day, 0.92 (95 CI, 0.87 0.97) for 1 2 drinks/day, 1.08 (95 CI, 1.01 1.15) for more than 2 4 drinks/day, and 1.14 (95 CI, 1.02 1.28) for more than 4 drinks/day. Light and moderate alcohol drinking was not associated with any hemorrhagic stroke subtype. High alcohol consumption >2 4 drinks/day) was associated with a non significant increased risk of both hemorrhagic stroke subtypes, and the relative risk for heavy drinking >4 drinks/day) were 1.67 (95 CI, 1.25 2.23) for intracerebral hemorrhage and 1.82 (95 CI, 1.18 2.82) for subarachnoid hemorrhage.ConclusionLight and moderate alcohol consumption was inversely associated only with ischemic stroke, whereas heavy drinking was associated with increased risk of all stroke types with a stronger association for hemorrhagic strokes.
BMC Medicine