From the Division of Cardiology, Department of Medicine (P.A., G.A.), University of Alabama at Birmingham.
Section of Cardiology, Birmingham Veterans Affairs Medical Center, AL (P.A.).
Arterioscler Thromb Vasc Biol. 2019 Apr;39(4):810-818. doi: 10.1161/ATVBAHA.118.311857.
Objective- Increased Lp(a) [lipoprotein(a)] is associated with coronary heart disease risk, but links with stroke are less consistent. Blacks have higher Lp(a) levels and stroke incidence than whites but have been underrepresented in studies. We hypothesized that Lp(a) is a risk factor for ischemic stroke and that risk differs by race. Approach and Results- REGARDS (Reasons for Geographic and Racial Differences in Stroke) recruited 30 239 black and white US adults aged ≥45 in 2003-2007 to study regional and racial differences in stroke mortality. We measured baseline Lp(a) by immunonephelometric assay in 572 cases of incident ischemic stroke and a 967-person cohort random sample. The hazard ratio of stroke by baseline Lp(a) was calculated using Cox proportional hazards models, stratified by race. Lp(a) was modeled in sex- and race-specific quartiles, given known differences in distributions by race and sex. Interactions were tested by including interaction terms in the proportional hazards models, with P<0.10 considered statistically significant. After adjustment for age, sex, and stroke risk factors, being in the fourth versus the first Lp(a) quartile was weakly associated with ischemic stroke overall, hazard ratio, 1.45 (95% CI, 0.96-2.19). In blacks, the hazard ratio was 1.96 (95% CI, 1.10-3.46), whereas in whites HR was 1.14 (95% CI, 0.64-2.04); P interaction=0.12. Lp(a) was lower in men than women, but associations with stroke in men and women were similar. Conclusions- We confirm that Lp(a) is a risk factor for ischemic stroke. Further research is needed to confirm the role of racial differences of the Lp(a) risk multiplier in ischemic stroke.
脂蛋白(a)[Lp(a)]升高与冠心病风险相关，但与中风的关联则不太一致。黑人的 Lp(a)水平和中风发病率高于白人，但在研究中代表性不足。我们假设 Lp(a)是缺血性中风的一个危险因素，且风险因种族而异。
REGARDS（中风地域和种族差异原因）研究于 2003 年至 2007 年招募了 30239 名年龄≥45 岁的美国黑人和白人成年人，以研究中风死亡率的地域和种族差异。我们使用免疫比浊法在 572 例新发缺血性中风病例和 967 人的队列随机样本中测量了基线 Lp(a)。使用 Cox 比例风险模型计算了按基线 Lp(a)分层的中风风险比。考虑到种族和性别分布的已知差异，按性别和种族特异性四分位数对 Lp(a)进行建模。通过在比例风险模型中包含交互项来检验交互作用，统计学显著性定义为 P<0.10。在校正年龄、性别和中风危险因素后，与处于 Lp(a)四分位第 1 位相比，处于第 4 位与缺血性中风总体相关，风险比为 1.45（95%CI，0.96-2.19）。在黑人中，风险比为 1.96（95%CI，1.10-3.46），而在白人中 HR 为 1.14（95%CI，0.64-2.04）；P 交互=0.12。男性的 Lp(a)水平低于女性，但男性和女性的中风与 Lp(a)的关联相似。
我们证实 Lp(a)是缺血性中风的一个危险因素。需要进一步的研究来证实 Lp(a)风险倍增器的种族差异在缺血性中风中的作用。
