Dibaba Daniel T, Xun Pengcheng, Fly Alyce D, Bidulescu Aurelian, Tsinovoi Cari L, Judd Suzanne E, McClure Leslie A, Cushman Mary, Unverzagt Frederick W, He Ka
Department of Epidemiology and Biostatistics, School of Public Health, Indiana University Bloomington, Bloomington, IN, USA.
Department of Vice Chancellor for Research/Tennessee Clinical and Translational Science Institute, University of Tennessee Health Science Center, Memphis, TN, USA.
J Stroke. 2019 Sep;21(3):312-323. doi: 10.5853/jos.2019.00542. Epub 2019 Sep 30.
Data on the association between calcium (Ca) and ischemic stroke are sparse and inconsistent. This study aimed to examine Ca intake and serum Ca levels in relation to risk of ischemic stroke.
The primary analysis included 19,553 participants from the Reasons for Geographic And Racial Differences in Stroke (REGARDS) study. A subcohort was randomly selected to create a case-cohort study (n=3,016), in which serum Ca levels were measured. Ischemic stroke cases were centrally adjudicated by physicians based on medical records. Cox proportional hazards regression for the cohort and weighted Cox proportional hazard regression with robust sandwich estimation method for the case-cohort analysis with adjustment for potential confounders were performed.
During a mean 8.3-year follow-up, 808 incident cases of ischemic stroke were documented. Comparing the highest quintile to the lowest, a statistically significant inverse association was observed between total Ca intake and risk of ischemic stroke (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.55 to 0.95; Plinear-trend=0.183); a restricted cubic spline analysis indicated a threshold effect like non-linear association of total Ca intake with ischemic stroke (Pnon-linear=0.006). In the case-cohort, serum Ca was inversely associated with the risk of ischemic stroke. Compared to the lowest, the highest quintile of serum Ca had a 27% lower risk of ischemic stroke (HR, 0.73; 95% CI, 0.53 to 0.99; Plinear-trend=0.013). Observed associations were mainly mediated by type 2 diabetes, hypertension, and cholesterol.
s These findings suggest that serum Ca has inverse and Ca intake has threshold effect like association with risk of ischemic stroke.
关于钙（Ca）与缺血性卒中之间关联的数据稀少且不一致。本研究旨在探讨钙摄入量和血清钙水平与缺血性卒中风险的关系。
主要分析纳入了来自卒中地理和种族差异原因（REGARDS）研究的19,553名参与者。随机选取一个亚队列以创建病例队列研究（n = 3,016），其中测量了血清钙水平。缺血性卒中病例由医生根据病历进行集中判定。对队列进行Cox比例风险回归分析，并对病例队列分析采用稳健三明治估计法进行加权Cox比例风险回归分析，同时对潜在混杂因素进行调整。
在平均8.3年的随访期间，记录了808例缺血性卒中事件。将最高五分位数与最低五分位数进行比较，观察到总钙摄入量与缺血性卒中风险之间存在统计学显著的负相关（风险比[HR]，0.72；95%置信区间[CI]，0.55至0.95；P线性趋势 = 0.183）；受限立方样条分析表明总钙摄入量与缺血性卒中存在非线性关联，呈现阈值效应（P非线性 = 0.006）。在病例队列中，血清钙与缺血性卒中风险呈负相关。与最低五分位数相比，血清钙最高五分位数的缺血性卒中风险降低27%（HR，0.73；95% CI，0.53至0.99；P线性趋势 = 0.013）。观察到的关联主要由2型糖尿病、高血压和胆固醇介导。
这些发现表明血清钙与缺血性卒中风险呈负相关，而钙摄入量与之存在阈值效应样的关联。
