Authors: Alison J. Price , DPhil, F. Lucy Wright , DPhil, Jane Green , DPhil, Angela Balkwill , MSc, Sau Wan Kan , MSc, TienYu Owen Yang , DPhil, Sarah Floud , PhD, Mary E. Kroll , DPhil, Rachel Simpson , MB, BCh, Cathie L.M. Sudlow , FRCP(E), Valerie Beral , FRS, Gillian K. Reeves , PhD
Publication date PMC-release 23 January 2018
Publisher: Lippincott Williams & Wilkins
To compare associations of behavioral and related factors for incident subarachnoid hemorrhage and intracerebral hemorrhage and ischemic stroke.
A total of 712,433 Million Women Study participants without prior stroke, heart disease, or cancer reported behavioral and related factors at baseline (1999–2007) and were followed up by record linkage to national hospital admission and death databases. Cox regression yielded adjusted relative risks (RRs) by type of stroke. Heterogeneity was assessed with χ 2 tests. When appropriate, meta-analyses were done of published prospective studies.
After 12.9 (SD 2.6) years of follow-up, 8,128 women had an incident ischemic stroke, 2,032 had intracerebral hemorrhage, and 1,536 had subarachnoid hemorrhage. In women with diabetes mellitus, the risk of ischemic stroke was substantially increased (RR 2.01, 95% confidence interval [CI] 1.84–2.20), risk of intracerebral hemorrhage was increased slightly (RR 1.31, 95% CI 1.04–1.65), but risk of subarachnoid hemorrhage was reduced (RR 0.43, 95% CI 0.26–0.69) (heterogeneity by stroke type, p < 0.0001). Stroke incidence was greater in women who rated their health as poor/fair compared to those who rated their health as excellent/good (RR 1.36, 95% CI 1.30–1.42). Among 565,850 women who rated their heath as excellent/good, current smokers were at an increased risk of all 3 stroke types, (although greater for subarachnoid hemorrhage [≥15 cigarettes/d vs never smoker, RR 4.75, 95% CI 4.12–5.47] than for intracerebral hemorrhage [RR 2.30, 95% CI 1.94–2.72] or ischemic stroke [RR 2.50, 95% CI 2.29–2.72]; heterogeneity p < 0.0001). Obesity was associated with an increased risk of ischemic stroke and a decreased risk of hemorrhagic stroke (heterogeneity p < 0.0001). Meta-analyses confirmed the associations and the heterogeneity across the 3 types of stroke.
Go to Neurology.org/N for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
Wellcome Trust, Postdoctoral Research Training Fellowship
(1)Medical Research Council (UK), grant no. MR/K02700X/1, co-PI, 2013-2018
(1) Cancer Research UK, Programme Grant no. C570/A16491, co-PI, 2014-2019
Husband of author: scientific advisory board of 'Meningitis Now' (a UK charity, i.e. non-profit)
Husband of author: Biomedical Research Centre, Imperial Healthcare NHS Trust, UK
(1) UK MRC and Wellcome Trust: UK Biobank programme renewal, ?35 million, 2010-2017 (co-I) (2) UK MRC, Dementias Platform UK programme grant, ?12 million, 2014-2019 (co-I) (3) UK MRC, Wellcome Trust, British Heart Foundation: UK Biobank imaging study, ?43 million, 2013-2022 (co-I) (4) European Union Innovative Medicines Initiative Horizon 2020 programme, ROADMAP (real world outcomes in Alzheimer's Disease), 8 million euros (about 50% EU, 50% EFPIA pharma company partners), 2016-2018 (co-I)
(1) British Heart Foundation, 2012-2017, RESTART trial of antiplatelet treatment in ICH ( co-I)
(1) Non-Executive Director, Medicines and Healthcare Regulatory Products Regulatory Agency
(1) Was a member of the Grail Inc. Population Study Scientific Advisory Board (2017).
(1) Medical Research Council, grant no MR/K02700X/1, Co-PI, Programme grant to support the Million Women Study cohort, 2013-2018.
(1) Cancer Research UK, grant no C570/A16491, Co-PI, Programme Grant to support the work of the Cancer Epidemiology Unit, 2014-2017.
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