Sustained smoking cessation best for lowering stroke risk

Sustained smoking cessation is associated with progressive reduction in the risk of ischaemic stroke, with substantial risk reduction observed after prolonged abstinence, according to a retrospective study.

Researchers used the Korean National Health Insurance Service database from 2002 to 2023 and identified adults with at least four health examinations, excluded those with prior cerebrovascular disease or major cardioembolic conditions.

Smoking status was classified as never smokers, sustained quitters, and current smokers. The primary outcome of incident ischaemic stroke was ascertained from claims records.

In total, 1,326,718 participants (mean age 49.12 years, 60.8 percent female, mean BMI 23.8 kg/m²) were included in the analysis. Of these, 1,038,850 were never smokers, 60,198 were sustained quitters, and 227,670 were current smokers. There were 24,791 incident strokes documented over 14,072,175 person-years.

Compared with current smokers, ischemic stroke risk generally decreased with increasing cessation duration, with the lowest risk was observed in the 6–7-year cessation group (<2 years: hazard ratio [HR], 0.67; 2–3 years: HR, 0.51; 4–5 years: HR, 0.47; 6–7 years: HR, 0.36; ≥8 years: HR, 0.46).

When never smokers were used as the reference group, the risk of ischaemic stroke observed among quitters with 2–3 years of sustained abstinence were close to those observed among never smokers.

In light of the findings, the researchers emphasized the importance of early smoking cessation and sustained long-term abstinence for stroke prevention.