Supplementary Material for: Age-period-cohort analysis of long-term trends in ischemic stroke mortality in China caused by specific risk factors from 1990 to 2019

Objective: To study the primary risk factors for the long-term trends of mortality rates in ischemic stroke (IS) in China.
Methods: Using the Global Burden of Disease Study 2019 (GBD 2019) database, research was conducted on the 11 primary risk factors for the mortality rates of IS in China from 1990 to 2019. This study employed Joinpoint regression software and the Age-Period-Cohort (APC) method to evaluate the trends of mortality rates divided by age, period, and cohort over time.
Results: From 1990 to 2019, the age-standardized mortality rate (ASMR) caused by a diet high in red meat and high body-mass index (BMI) in China showed an upward trend. ASMR increased first and then decreased due to smoking, diet high in sodium, particulate matter pollution, high fasting plasma glucose, and high systolic blood pressure. Low-density lipoprotein cholesterol (LDL-C), kidney dysfunction, low temperature, and lead exposure remained relatively stable during this period. In the 35-45 age group, the mortality rate of IS due to high LDL-C was up to about 60%, and smoking affected men more than women. Overall, high LDL-C, high systolic blood pressure, and particulate matter pollution were the most common risk factors in patients with IS. The risk of death rose with age. The period and cohort relative risks showed that metabolic risk factors had the greatest impact on the mortality of IS.
Conclusion: Metabolic risk factors have become the primary risk factors for the ASMR of IS in China. Relevant authorities should pay attention to their long-term effects on IS. Effective public health policies and interventions should be implemented to reduce the burden of IS.

研究目标：探究中国缺血性脑卒中（ischemic stroke, IS）死亡率长期趋势的主要危险因素。
研究方法：本研究依托2019年全球疾病负担研究（Global Burden of Disease Study 2019, GBD 2019）数据库，针对1990年至2019年中国缺血性脑卒中死亡率相关的11项主要危险因素展开分析。本研究采用Joinpoint回归软件与年龄-时期-队列（Age-Period-Cohort, APC）分析方法，对按年龄、时期及队列分组的死亡率长期变化趋势进行评估。
研究结果：1990年至2019年间，中国因红肉过量摄入与高体质量指数（body-mass index, BMI）导致的年龄标化死亡率（age-standardized mortality rate, ASMR）呈上升趋势。而因吸烟、高钠饮食、颗粒物污染、空腹血糖升高及收缩压升高所导致的年龄标化死亡率则呈现先升后降的变化趋势。低密度脂蛋白胆固醇（low-density lipoprotein cholesterol, LDL-C）升高、肾功能不全、低温暴露与铅暴露相关的年龄标化死亡率在此期间则保持相对稳定。在35~45岁年龄组中，由高LDL-C导致的缺血性脑卒中死亡率占比可达约60%，且吸烟对男性的影响程度高于女性。整体而言，高LDL-C、高收缩压与颗粒物污染是缺血性脑卒中患者最主要的危险因素。死亡风险随年龄增长而升高。时期与队列相对风险分析结果显示，代谢类危险因素对缺血性脑卒中死亡率的影响最为显著。
研究结论：代谢类危险因素已成为中国缺血性脑卒中年龄标化死亡率的主要危险因素。相关主管部门应重视其对缺血性脑卒中的长期影响，并制定有效的公共卫生政策与干预措施，以减轻缺血性脑卒中带来的疾病负担。