总胆固醇纵向轨迹对50岁以上人群新发缺血性脑卒中影响的前瞻性队列研究

目的　探究总胆固醇（TC）纵向轨迹对50岁以上人群新发缺血性脑卒中的影响。方法　采用基于开滦研究的前瞻性队列研究方法,将第1、2、3次健康体检TC资料完整且第3次体检前无脑卒中病史的50岁以上（第1次体检年龄≥50岁）观察者（n=23 830）作为重复测量观察人群。采用SAS 9.4统计软件进行分析,依据SAS Proc Traj程序建立观察对象TC的轨迹模型并分组：低-稳定组（n=9 699,40.70%）、中-稳定组（n=11 723,49.19%）、高-稳定组（n= 2 408,10.10%）,用Kaplan-Meier法比较不同TC轨迹组缺血性脑卒中事件的累积发病率,采用Cox回归模型分析TC纵向轨迹对50岁以上新发缺血性脑卒中的影响,通过是否服用降脂药分层,重复上述Cox模型,以排除是否服用降脂药对结果产生的混杂效应。结果　随访（6.89±0.72）年,低-稳定组、中-稳定组、高-稳定组缺血性脑卒中累积发病率分别为4.42%、4.88%和5.72%,经Log-rank检验,差异有统计学意义（χ2=8.234,P＜0.05）。Cox回归分析：校正性别等影响因素后,与低-稳定组相比,中-稳定组、高-稳定组发生缺血性脑卒中的HR（95%CI）分别是1.222（1.062~1.407）、1.400（1.122~1.747）;分别增加校正基线单次TC测量值及TC变化值后,TC纵向轨迹水平升高仍是缺血性脑卒中发生的危险因素。在未服药人群中,上述趋势仍存在;而服药人群中,TC纵向轨迹水平对缺血性脑卒中的影响无统计学意义。结论　TC纵向轨迹水平升高是50岁以上人群缺血性脑卒中的危险因素,独立于基线单次TC测量值及变化值,服用降脂药可降低TC纵向轨迹水平升高对50岁以上人群缺血性脑卒中的影响。

A prospective cohort study of the effect of total cholesterol longitudinal trajectory on the new onset ischemia stroke in patients over 50 years of age

Objective To explore the effect of total cholesterol (TC) longitudinal trajectory on the new onset ischemia stroke of the population over 50 years of age. Methods A prospective cohort study was conducted based on kailuan research cohort. The population over 50 years of age (n=23 830) with complete TC data in the first, second and third measurements and no history of stroke before the third measurement was used as the observation population. According to the TC longitudinal trajectory, three TC trajectory groups were determined: low-stable group (n=9 699, 40.70%), medium-stable group (n=11 723, 49.19%) and high-stable group (n=2 408, 10.10%). The cumulative incidences of ischemic stroke in different TC trajectory groups were compared by Kaplan-Meier method. Cox regression model was used to analyze the effect of TC longitudinal trajectory on the ischemic stroke of the population over 50 years of age. Results During the follow-up (6.89±0.72) years, the cumulative incidences of ischemic stroke in the different TC trajectory groups were 4.42%, 4.88% and 5.72%, respectively, and Log-rank test showed that the differences between the three groups were statistically significant (χ2=8.234, P＜0.05). Cox regression analysis showed that after adjusting for gender and other influencing factors, the HR values (95%CI) of ischemic stroke were 1.222 (1.062-1.407) and 1.400 (1.122-1.747) in medium-stable and high-stable groups compared with those of low-stable group. After adjusting for baseline TC and the TC change value, respectively, the elevated TC longitudinal trajectory level was also the risk factor for ischemic stroke. These trends persisted in people who did not take lipid-lowering drugs. However, there were no significant differences in the levels of TC longitudinal trajectory on ischemic stroke of patients taking drug. Conclusion The elevated TC longitudinal trajectory level is a risk factor for ischemic stroke in the population over 50 years of age, which is independent to the baseline single TC measurement and change value. The use of lipid-lowering drugs can reduce the influence of the increased longitudinal trajectory level of TC on ischemic stroke in the population over 50 years old.