Department of Endocrinology, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands.
Eur J Clin Invest. 2012 Nov;42(11):1235-43. doi: 10.1111/j.1365-2362.2012.02719.x. Epub 2012 Sep 8.
Lipoprotein-associated phospholipase A(2) (Lp-PLA(2) ) is a novel cardiovascular risk marker, which is predominantly complexed to apolipoprotein (apo) B-containing lipoproteins in human plasma. As increasing dietary sodium intake may decrease plasma apoB-containing lipoproteins, we tested whether a sodium challenge lowers plasma Lp-PLA(2) mass, as well as the levels of apoB-containing lipoprotein particles carrying Lp-PLA(2) (apoB-Lp-PLA(2) ), employing a newly developed enzyme-linked immunosorbent assay.
In 45 women and 31 men (mean age 44 ± 14 years), plasma Lp-PLA(2) mass (turbidimetric immunoassay), the level of apoB-Lp-PLA(2) , expressed in apoB concentration and lipoproteins were measured in response to a 3-day challenge with 9 g sodium chloride tablets daily.
Urinary sodium excretion increased from 165 ± 60 to 321 ± 70 mmol/24 h (P<0.001) after salt loading. Plasma Lp-PLA(2) mass decreased from 618 (493-719) to 588 (465-698) μg/L (P<0.001), and apoB-Lp-PLA(2) decreased from 0.276 (0.200-0.351) to 0.256 (0.189-0.328) g LDL protein/L (P=0.004) in response to the sodium challenge together with decreases in plasma total cholesterol, nonhigh-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein B and the total cholesterol/HDL cholesterol ratio (P<0.01 for all). Changes in plasma Lp-PLA(2) mass were correlated positively with changes in total cholesterol, LDL cholesterol and non-HDL cholesterol (r=0.260-0.276, P<0.05 to P<0.02), whereas changes in apoB-Lp-PLA(2) were correlated positively with changes in non-HDL cholesterol and in the total cholesterol/HDL cholesterol ratio (r=0.232-0.385, P<0.05-0.01).
Both plasma Lp-PLA(2) mass levels and apoB-Lp-PLA(2) decrease in response to a short-term oral sodium challenge.
脂蛋白相关磷脂酶 A(2)（Lp-PLA(2)）是一种新型心血管风险标志物，主要与人类血浆中的载脂蛋白（apo）B 含脂蛋白结合。由于增加饮食中的钠摄入量可能会降低血浆 apoB 含脂蛋白，因此我们检测了钠负荷是否会降低血浆 Lp-PLA(2)质量，以及携带 Lp-PLA(2)的 apoB 含脂蛋白颗粒的水平（apoB-Lp-PLA(2)），采用了新开发的酶联免疫吸附测定法。
在 45 名女性和 31 名男性（平均年龄 44±14 岁）中，采用浊度免疫测定法测定血浆 Lp-PLA(2)质量，采用酶联免疫吸附测定法测定 apoB-Lp-PLA(2)的水平，以载脂蛋白 B 浓度和脂蛋白表示，并在 3 天内每天服用 9 g 氯化钠片进行盐负荷。
盐负荷后，尿钠排泄量从 165±60 增加到 321±70mmol/24h（P<0.001）。血浆 Lp-PLA(2)质量从 618（493-719）减少到 588（465-698）μg/L（P<0.001），apoB-Lp-PLA(2)从 0.276（0.200-0.351）减少到 0.256（0.189-0.328）g LDL 蛋白/L（P=0.004），同时血浆总胆固醇、非高密度脂蛋白（HDL）胆固醇、低密度脂蛋白（LDL）胆固醇、载脂蛋白 B 和总胆固醇/HDL 胆固醇比值降低（P<0.01）。血浆 Lp-PLA(2)质量的变化与总胆固醇、LDL 胆固醇和非 HDL 胆固醇的变化呈正相关（r=0.260-0.276，P<0.05 至 P<0.02），而 apoB-Lp-PLA(2)的变化与非 HDL 胆固醇和总胆固醇/HDL 胆固醇比值的变化呈正相关（r=0.232-0.385，P<0.05-0.01）。
短期口服钠负荷后，血浆 Lp-PLA(2)质量水平和 apoB-Lp-PLA(2)均降低。
