Article Text
Abstract
Background Stroke is increasingly prevalent at younger ages but the risk factors are uncertain. We examined the association between adolescent cognitive function and early-onset stroke.
Methods This was a nationwide population-based cohort study of 1 741 345 Israeli adolescents (42% women) who underwent comprehensive cognitive function tests at age 16–20 years, before mandatory military service, during 1987–2012. Cognitive function (range: 1–9) was categorised as low (1–3, corresponding to IQ score below 89), medium (4–7, IQ score range: 89–118), or high (8–9, IQ score above 118). Participant data were linked to the Israeli National Stroke Registry. Cox proportional hazard models were used to estimate risks for the first occurrence of ischaemic stroke during 2014–2018.
Results During 8 689 329 person-years of follow-up, up to a maximum age of 50 years, 908 first stroke events occurred (767 ischaemic and 141 haemorrhagic). Compared with a reference group of people with high cognitive function, body mass index-adjusted and sociodemographic-adjusted HRs (95% CIs) for early-onset stroke were 1.78 (1.33–2.38) in medium and 2.68 (1.96–3.67) in low cognitive function groups. There was evidence of a dose–response relationship (P for trend <0.0001) such that one-unit of lower cognitive function z-score was associated with a 33% increased risk of stroke (1.33; 1.23–1.42). These associations were similar for ischaemic stroke but lower for haemorrhagic stroke; persisted in sensitivity analyses that accounted for diabetes status and hypertension; and were evident before age 40 years.
Conclusions Alongside adolescent obesity and hypertension, lower cognitive function may be a risk factor for early-onset stroke.
- stroke
- adolescent
- cognition
Data availability statement
Data are available upon reasonable request. The data are not publicly available due to governmental and ethical restrictions. Interested parties can contact the corresponding author via email.
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Data availability statement
Data are available upon reasonable request. The data are not publicly available due to governmental and ethical restrictions. Interested parties can contact the corresponding author via email.
Footnotes
Contributors AB and CDB wrote the original draft. AB, CDB, ED and GT performed the formal analysis. AB, CDB and GT conceptualised the study, designed the methodology and directly accessed and verified the underlying data reported in the manuscript. CL, ML, IZ, AMT, GY, RCG, HG, TC-Y, YL, DB, DT, AF and AA reviewed and edited the manuscript. GT supervised the study. GT is the guarantor of this work and, as such, had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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