Smoking may double Risk of Cryptogenic Ischemic Stroke, suggests research
Researchers have found in a new study that smoking doubles the risk of cryptogenic ischemic stroke (CIS). The strongest association was observed in men and individuals aged 45-49 years.
The incidence of ischemic stroke in the young is increasing and driven by cryptogenic strokes. Smoking is a well-documented risk factor with a high prevalence in young ischemic strokes. We sought to determine the association between smoking and young cryptogenic ischemic stroke (CIS) in a large multicenter case-control study. In the Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome (SECRETO; NCT01934725) study, patients with CIS aged 18-49 years were prospectively recruited within 2 weeks of symptom onset from 19 European stroke centers. One sex-matched and age-matched (±5 years) stroke-free control was recruited per patient.
Data on tobacco use and intensity of use, socioeconomic status, and comorbidities were collected using a standardized questionnaire. Conditional logistic regression with adjustment for low education status and vascular risk factors was used to assess the association between smoking and intensity of smoking and CIS.
Results: A total of 546 young patients with CIS (47.3% female) and their matched controls were included in the analysis. Univariate comparison between patients and controls showed a significant difference in low education status (55.6% vs 35.2%, p ≤ 0.001), hypertension (34.7% vs 26.8%, p ≤ 0.005), obesity (59.3% vs 44.4%, p ≤ 0.001), physical inactivity (29.4% vs 23.6%, p ≤ 0.02), smoking (32.8% vs 14.8%, p ≤ 0.001), and heavy alcohol use (13.7% vs 6.7%, p ≤ 0.001). Conditional logistic regression after adjustment showed an association between smoking and young CIS in the whole cohort with an odds ratio of 2.39 (95% CI 1.65–3.47), in men with 3.34 (1.91–5.84), and in all age groups-highest in the 45–49-year age group—with 3.77 (1.74–8.17).
Analysis of smoking intensity by pack year showed the strongest association in the group with >20 pack years with an odds ratio of 4.30 (2.10–8.81), particularly in men (6.97 (2.58–18.82)) and the 45–49-year age group (4.91 (1.74–13.85)). Both smoking and high-intensity smoking were associated with CIS in the young, particularly in men and the 45–49-year age group.
Reference:
Ferdinand P, Bajpai R, Von Sarnowski B, et al. Association of Smoking and Young Cryptogenic Ischemic Stroke: A Case-Control Study. Neurology Open Access. 2025;1(1). doi:10.1212/WN9.0000000000000003.
