Cao Jing, Steffen Brian T, Budoff Matthew, Post Wendy S, Thanassoulis George, Kestenbaum Bryan, McConnell Joseph P, Warnick Russell, Guan Weihua, Tsai Michael Y
From the Department of Laboratory Medicine and Pathology (J.C., B.T.S., M.Y.T.), Division of Biostatistics, School of Public Health (W.G.), University of Minnesota, Minneapolis; Department of Medicine, University of California, Los Angeles (M.B.); Department of Medicine, John Hopkins University, Baltimore, MD (W.S.P.); Department of Medicine, McGill University, Montreal, Québec, Canada (G.T.); Division of Nephrology, Kidney Research Institute, University of Washington, Seattle (B.K.); and Health Diagnostics Laboratory, Richmond, VA (J.P.M., R.W.).
Arterioscler Thromb Vasc Biol. 2016 May;36(5):1003-9. doi: 10.1161/ATVBAHA.115.306683. Epub 2016 Mar 3.
Lipoprotein(a) [Lp(a)] is a risk factor for calcific aortic valve disease (CAVD) but has not been evaluated across multiple races/ethnicities. This study aimed to determine whether Lp(a) cutoff values used in clinical laboratories to assess risk of cardiovascular disease identify subclinical CAVD and its severity and whether significant relations are observed across race/ethnicity.
Lp(a) concentrations were measured using a turbidimetric immunoassay, and subclinical CAVD was measured by quantifying aortic valve calcification (AVC) through computed tomographic scanning in 4678 participants of the Multi-Ethnic Study of Atherosclerosis. Relative risk and ordered logistic regression analysis determined cross-sectional associations of Lp(a) with AVC and its severity, respectively. The conventional 30 mg/dL Lp(a) clinical cutoff was associated with AVC in white (relative risk: 1.56; confidence interval: 1.24-1.96) and was borderline significant (P=0.059) in black study participants (relative risk: 1.55; confidence interval: 0.98-2.44). Whites with levels ≥50 mg/dL also showed higher prevalence of AVC (relative risk: 1.72; confidence interval: 1.36-2.17) than those below this level. Significant associations were observed between Lp(a) and degree of AVC in both white and black individuals. The presence of existing coronary artery calcification did not affect these associations of Lp(a) and CAVD. There were no significant findings in Hispanics or Chinese.
Lp(a) cutoff values that are currently used to assess cardiovascular risk seem to be applicable to CAVD, but our results suggest race/ethnicity may be important in cutoff selection. Further studies are warranted to determine whether race/ethnicity influences Lp(a) and risk of CAVD incidence and its progression.
脂蛋白(a)[Lp(a)]是钙化性主动脉瓣疾病（CAVD）的一个危险因素，但尚未在多个种族/族裔中进行评估。本研究旨在确定临床实验室用于评估心血管疾病风险的Lp(a)临界值是否能识别亚临床CAVD及其严重程度，以及是否在不同种族/族裔中观察到显著关系。
采用比浊免疫分析法测量Lp(a)浓度，并通过计算机断层扫描对动脉粥样硬化多族裔研究的4678名参与者的主动脉瓣钙化（AVC）进行量化，以测量亚临床CAVD。相对风险和有序逻辑回归分析分别确定了Lp(a)与AVC及其严重程度的横断面关联。传统的30mg/dL Lp(a)临床临界值与白人的AVC相关（相对风险：1.56；置信区间：1.24-1.96），在黑人研究参与者中接近显著（P=0.059）（相对风险：1.55；置信区间：0.98-2.44）。Lp(a)水平≥50mg/dL的白人的AVC患病率（相对风险：1.72；置信区间：1.36-2.17）也高于该水平以下的白人。在白人和黑人个体中均观察到Lp(a)与AVC程度之间存在显著关联。现有的冠状动脉钙化的存在并不影响Lp(a)与CAVD的这些关联。在西班牙裔或中国人中未发现显著结果。
目前用于评估心血管风险的Lp(a)临界值似乎适用于CAVD，但我们的结果表明种族/族裔在临界值选择中可能很重要。有必要进一步研究以确定种族/族裔是否影响Lp(a)以及CAVD发病及其进展的风险。
