Division of Neurology, Hamilton Health Sciences, McMaster University and Population Health Research Institute, Hamilton General Hospital, Hamilton, ON, Canada.
Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
Int J Stroke. 2022 Oct;17(9):1021-1029. doi: 10.1177/17474930211070682. Epub 2022 Jan 11.
The incidence of stroke in developed countries is increasing selectively in young individuals, but whether this is secondary to traditional vascular risk factors is unknown.
We used the Canadian Community Health Survey from 2000 to 2016 to create a large population-representative cohort of individuals over the age of 30 and free from prior stroke. All analyses were stratified by age decile. We linked with administrative databases to determine emergency department visits or hospitalizations for acute stroke until December 2017. We calculated time trends in risk factor prevalence (hypertension, diabetes, obesity, and smoking) using meta-regression. We used Cox proportional hazard models to evaluate the association between vascular risk factors and stroke risk, adjusted for demographic, co-morbid, and social variables. We used competing risk regression to account for deaths and calculated population-attributable fractions. In a sensitivity analysis, we excluded those with prior heart disease or cancer.
We included 492,400 people in the analysis with 8865 stroke events over a median follow-up time of 8.3 years. Prevalence of hypertension, diabetes, and obesity increased over time while smoking decreased. Associations of diabetes, hypertension, and obesity with stroke risk were progressively stronger at younger age (adjusted hazard ratio for diabetes was 4.47, 95% confidence interval (CI) = 1.95-10.28 at age 30-39, vs 1.21, 95% CI = 0.93-1.57 at age 80+), although the obesity association was attenuated with adjustment. Smoking was associated with higher risk of stroke without a gradient across age deciles, although had the greatest population-attributable fraction at younger age. The hazard ratio for stroke with multiple concurrent risk factors was much higher at younger age (adjusted hazard ratio for 3-4 risk factors was 8.60, 95% CI = 2.97-24.9 at age 30-39 vs 1.61, 95% CI = 0.88-2.97 at age 80+) and results were consistent when accounting for the competing risk of death and excluding those with prior heart disease or cancer.
Diabetes and hypertension were associated with progressively elevated relative risk of stroke in younger individuals and prevalence was increasing over time. The association of obesity with stroke was not significant after adjustment for other factors. Smoking had the greatest prevalence and population-attributable fraction for stroke at younger age. Our findings assist in understanding the relationship between vascular risk factors and stroke across the life span and planning public health measures to lower stroke incidence in the young.
在发达国家，中风的发病率在年轻人中选择性地增加，但这是否是传统血管危险因素的结果尚不清楚。
我们使用了 2000 年至 2016 年的加拿大社区健康调查，创建了一个年龄在 30 岁以上且无既往中风的大型人群代表性队列。所有分析均按年龄十分位数分层。我们与行政数据库相关联，以确定截至 2017 年 12 月的急性中风急诊就诊或住院情况。我们使用荟萃回归来计算危险因素（高血压、糖尿病、肥胖和吸烟）的流行率趋势。我们使用 Cox 比例风险模型来评估血管危险因素与中风风险之间的关联，并调整了人口统计学、合并症和社会变量。我们使用竞争风险回归来考虑死亡，并计算人群归因分数。在敏感性分析中，我们排除了那些有既往心脏病或癌症的人。
我们纳入了 492400 名分析对象，中位随访时间为 8.3 年，发生了 8865 例中风事件。高血压、糖尿病和肥胖的患病率随时间而增加，而吸烟则减少。糖尿病、高血压和肥胖与中风风险的关联在年轻人群中逐渐增强（年龄在 30-39 岁的糖尿病调整后的危险比为 4.47，95%置信区间（CI）为 1.95-10.28，而年龄在 80 岁及以上的糖尿病调整后的危险比为 1.21，95%CI 为 0.93-1.57），尽管肥胖的关联在调整后减弱。吸烟与中风风险增加有关，而与年龄十分位数无关，但在年轻人群中具有最大的人群归因分数。具有多个并存危险因素的中风风险比在年轻人群中更高（年龄在 30-39 岁时，有 3-4 个危险因素的调整后的危险比为 8.60，95%CI 为 2.97-24.9，而年龄在 80 岁及以上时，调整后的危险比为 1.61，95%CI 为 0.88-2.97），并且在考虑死亡的竞争风险和排除有既往心脏病或癌症的人群时，结果仍然一致。
糖尿病和高血压与年轻人群中风的相对风险逐渐升高有关，并且随着时间的推移，其患病率也在增加。肥胖与中风的关联在调整其他因素后并不显著。吸烟在年轻人群中具有最高的中风患病率和人群归因分数。我们的研究结果有助于理解血管危险因素与整个生命周期中风之间的关系，并为降低年轻人中风发病率制定公共卫生措施提供参考。
