Serum lipid profile,oxidative status,and paraoxonase 1 activity in hyperemesis gravidarum

The aim of this study was to investigate lipid profile, paraoxonase 1 (PON1) activity, and oxidative stress status in the serum of hyperemesis gravidarum (HG) patients. Thirty‐six HG cases and 36 normal pregnants were included in the study. Serum total cholesterol (TC), triglyceride (TG), high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol (LDL‐C), apoproteins A1 (apo A1) and B (apo B), malondialdehyde (MDA), and total antioxidant activity (TAO) values and PON1 and arylesterase activities were determined. Although serum TC, TG, LDL‐C, and apo B levels were not different among; the groups (P>0.05), HDL‐C (P=0.01) and apo A1 (P=0.007) levels were lower in HG patients than in normal pregnants. HG group had significantly lower serum PON1 (P=0.03) and arylesterase activities (P=0.03) compared with the control group. Additionally, mean TAO values were lower (P=0.01) and MDA levels were higher (P=0.02) in HG group than in the healthy pregnants. A significant negative correlation between PON1 and MDA was found in HG group (r=?0.33, P<0.05). The findings of this study have revealed that HG may be one of the conditions in which oxidant and antioxidant balance is impaired. J. Clin. Lab. Anal. 23:105–109, 2009. © 2009 Wiley‐Liss, Inc.     

Serum levels of lipids, lipoproteins and paraoxonase activity in pre-eclampsia

Serum paraoxonase 1 (PON1) activity and the oxidation of lipoproteins were investigated in 35 women with pre-eclampsia and in 35 healthy control women with normal pregnancies. Blood pressure, body mass index (BMI), serum levels of total cholesterol, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and lipoprotein (a) (Lp[a]), and PON1 activity were assessed. There were no significant between-group differences in subject age, gestational age at diagnosis of pre-eclampsia, BMI, serum total cholesterol, triglycerides, LDL and ApoB levels. Mean systolic and diastolic blood pressures and serum Lp(a) were significantly higher in subjects with pre-eclampsia than in controls. Mean serum HDL, ApoA1 and PON1 activity were significantly lower in subjects with pre-eclampsia compared with controls. In conclusion, lipids and oxidized lipoproteins may play important roles in the pathogenesis of pre-eclampsia.     

妊娠期肝内胆汁淤积症患者血脂水平与新生儿血气分析值的相关性分析

目的:探讨妊娠期肝内胆汁淤积症(intrahepatic cholestasis of pregnancy,ICP)患者血脂水平与围生儿预后的关系。方法:选择ICP晚期妊娠60例,正常晚期妊娠25例,测定母体血总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)浓度及围生儿出生即刻脐动脉血气分析值[pH值、血氧分压(PO2)、二氧化碳分压(PCO2)],并进行相关性分析。结果:ICP孕妇血TC、TG、LDL值明显升高,HDL值明显降低,ICP孕妇TC、TG、LDL值与PCO2呈正相关,与pH值及PO2呈负相关,HDL值与pH值及PO2呈正相关,与PCO2呈负相关。结论:ICP孕妇血脂水平与围生儿预后具有相关性,血脂检测应列为ICP的常规。     

血清脂质、脂蛋白胆固醇和载脂蛋白在冠心病中的临床意义

目的研究冠心病患者的血清脂质、脂蛋白胆固醇和载脂蛋白的变化、辨别力和诊断价值。方法测定64例冠心病(CHD)患者和60例正常人的血脂、脂蛋白胆固醇和载脂蛋白,并比较计算其辨别力和诊断价值。结果和结论冠心病患者的TC(女)、TG、LDL-C、ApoB、LDL-C/HDL-C和ApoB/ApoAI明显高于正常人(P<0.05),HDL2-C、HDL3-C、HDL-C、ApoAI和HDL-C/TC明显低于正常人(P<0.05)。由HDL-C、TC和TG血脂三项可代替HDL-C、LDL-C、VLDL-C、TC和TG血脂五项,对冠心病的诊断目前有应用价值,若加上HDL2-C和HDL3-C或ApoAI和ApoB,则对冠心病的诊断更有意义。     

Concentration of Lp(a) and other apolipoproteins in predialysis, hemodialysis, chronic ambulatory peritoneal dialysis and post-transplant patients.

Serum levels of lipids, lipoprotein(a) Lp(a) and other apolipoproteins were determined in 47 predialysis patients, 40 hemodialysis (HD) patients, 39 chronic ambulatory peritoneal dialysis (CAPD) patients, 11 patients after kidney transplantation and 47 healthy subjects as reference group. The predialysis, HD, and CAPD patients had disturbances in the concentration of serum triglyceride (TG), high density lipoprotein (HDL)-cholesterol, apolipoprotein AI (apoAI), total apoCIII, apoCIII present in the particles without apoB (apoCIII non B), and Lp(a) and HDL-cholesterol, low density lipoprotein (LDL)-cholesterol/HDL-cholesterol, HDL-cholesterol/apoAI, apoAI/apoB, and apoAI/apoCIII ratios. Predialysis patients had significantly lower concentrations of HDL-cholesterol and total apoE levels than CAPD patients and total apoE level than HD patients. Moreover, both HD and CAPD patients had significantly increased levels of apoB containing apoE (apoB:E) and apoB containing apoCIII (apoB:CIII). The concentrations of serum TG, total cholesterol, LDL-cholesterol, apoB, Lp(a) in CAPD patients were statistically higher than in HD patients. The patients after transplantation demonstrated normalization of lipid and lipoprotein parameters and lipoprotein ratios except serum levels of TG, total apoCIII, apoCIII non B and the apoAI/apoCIII ratio. We concluded that abnormal lipid and lipoprotein concentrations in patients with uremia may be the cause of their high risk of atherosclerosis, but posttransplant patients exhibited improved levels of serum lipids, Lp(a) and other lipoprotein parameters and lipoprotein composition, which could be an index of decreased atherogenic status.     

Characterization of antioxidant/anti-inflammatory properties and apoA-I-containing subpopulations of HDL from family subjects with monogenic low HDL disorders

BackgroundGenetic factors regulate both high-density lipoprotein (HDL) levels and functionality, thus affecting HDL antiatherogenic properties. We characterized the HDL antioxidant/anti-inflammatory properties and apoA-I-containing subpopulations in families with monogenic low HDL disorders.MethodsSubjects with mutations in apolipoprotein A-I (apoA-I), ATP-binding cassette transporter A1 (ABCA1) or lecithin:cholesterol acyltransferase (LCAT) and family controls were studied. HDL antioxidant/anti-inflammatory properties were assayed by an in vitro fluorometric method and HDL-associated paraoxonase-1 (PON1), platelet activating factor-acetylhydrolase (PAF-AH), LCAT, malondialdehyde (MDA), PAF and serum amyloid A (SAA) were measured. ApoA-I-containing HDL subpopulations were analyzed by two-dimensional non-denaturing gel electrophoresis.ResultsApoA-I heterozygotes and subjects with partial or complete ABCA1 or LCAT deficiency had HDL with reduced antioxidant/anti-inflammatory properties and increased MDA levels. HDL-PON1 activity was reduced in apoA-I heterozygotes and in subjects with complete ABCA1 deficiency. HDL-PAF-AH activity was reduced in subjects with partial or complete ABCA1 deficiency or complete LCAT deficiency. HDL-LCAT activity was reduced in all LCAT mutation carriers. HDL-PAF levels were increased in apoA-I heterozygotes. HDL-SAA levels were increased in subjects with complete ABCA1 deficiency. ApoA-I, ABCA1 and LCAT heterozygotes were depleted of the large α1 HDL subpopulation. Subjects with complete LCAT deficiency showed mostly the small α4 HDL subpopulation and subjects with complete ABCA1 deficiency the α4 and preβ HDL subpopulations.ConclusionsThis study shows that mutations in apoA-I, ABCA1 and LCAT have direct effect on the antioxidant/anti-inflammatory properties of HDL. Furthermore, our study shows the effect of specific mutations on the apoA-I-containing HDL subpopulation profiles.     

The effect of atorvastatin therapy on lecithin:cholesterol acyltransferase, cholesteryl ester transfer protein and the antioxidant paraoxonase

OBJECTIVES: The aim of our study was to examine the influence of atorvastatin on lipid parameters, particularly on HDL, and on the activity of LCAT and CETP and how they affect the activity of the HDL-associated antioxidant enzyme paraoxonase. DESIGN AND METHODS: Thirty-three patients with types II.a and II.b primary hyperlipoproteinemia were enrolled into our study. The patients received atorvastatin, 20 mg daily, for 3 months. We measured the serum paraoxonase activity and concentration, oxidized LDL, LCAT and CETP activities. RESULTS: Atorvastatin significantly reduced the levels of cholesterol, triglyceride, LDL-C and apoB, while it did not influence the levels of HDL-C and apo A-I. The increases in serum PON-specific activity, PON/HDL ratio and LCAT activity were significant, while oxLDL and CETP activities were significantly decreased. CONCLUSION: Atorvastatin may influence the composition and function of HDL, thereby possibly increasing the activity of paraoxonase and preventing atherosclerosis.     

Alterations in high-density lipoprotein subfractions during postprandial lipidaemia induced by fat with and without ethanol

1. Serum lipid and apolipoprotein levels, distribution and composition of high-density lipoprotein (HDL) subfractions and lecithin:cholesterol acryltransferase activity were analysed in nine normolipidaemic subjects, in whom a hypertriglyceridaemic state was induced by the acute administration of ethanol (40 g) plus fat (70 g) or of fat only. 2. Triglyceride (TG) levels increased by 180% 4-6 h after fat plus ethanol intake, the hypertriglyceridaemic response being inversely correlated with the basal HDL2 mass (r = -0.82). Serum apolipoprotein (apo) B levels rose by 8%, HDL-cholesterol decreased by 10% and HDL-TG increased by 57% at 6-8 h. 3. When ethanol was omitted, serum cholesterol and TG rose by 6% and 70%, respectively; both apo AI and apo B levels went up by 8%, whereas HDL-cholesterol rose progressively (15%) at 12 h. 4. The flotation rates of both HDL2 and HDL3 increased, reaching a maximum 6-8 h after ethanol plus fat intake. These changes were due to an increase in TG and phospholipid contents, whereas cholesteryl esters and proteins decreased. 5. The alterations in HDL are attributable to the increase in TG-rich lipoproteins, to the stimulated cholesterol esterification (+15%) and to an enhanced transfer of newly formed cholesteryl esters to apo-B-containing lipoproteins in exchange for TG. 6. Changes in HDL properties were evident only when ethanol was given concomitantly with fat. 7. These findings suggest that in the postprandial phase lipoprotein changes may occur, which facilitate an improved removal of cholesterol from tissues.     

Paraoxonase inhibits high-density lipoprotein oxidation and preserves its functions. A possible peroxidative role for paraoxonase.

HDL levels are inversely related to the risk of developing atherosclerosis. In serum, paraoxonase (PON) is associated with HDL, and was shown to inhibit LDL oxidation. Whether PON also protects HDL from oxidation is unknown, and was determined in the present study. In humans, we found serum HDL PON activity and HDL susceptibility to oxidation to be inversely correlated (r2 = 0.77, n = 15). Supplementing human HDL with purified PON inhibited copper-induced HDL oxidation in a concentration-dependent manner. Adding PON to HDL prolonged the oxidation lag phase and reduced HDL peroxide and aldehyde formation by up to 95%. This inhibitory effect was most pronounced when PON was added before oxidation initiation. When purified PON was added to whole serum, essentially all of it became HDL-associated. The PON-enriched HDL was more resistant to copper ion-induced oxidation than was control HDL. Compared with control HDL, HDL from PON-treated serum showed a 66% prolongation in the lag phase of its oxidation, and up to a 40% reduction in peroxide and aldehyde content. In contrast, in the presence of various PON inhibitors, HDL oxidation induced by either copper ions or by a free radical generating system was markedly enhanced. As PON inhibited HDL oxidation, two major functions of HDL were assessed: macrophage cholesterol efflux, and LDL protection from oxidation. Compared with oxidized untreated HDL, oxidized PON-treated HDL caused a 45% increase in cellular cholesterol efflux from J-774 A.1 macrophages. Both HDL-associated PON and purified PON were potent inhibitors of LDL oxidation. Searching for a possible mechanism for PON-induced inhibition of HDL oxidation revealed PON (2 paraoxonase U/ml)-mediated hydrolysis of lipid peroxides (by 19%) and of cholesteryl linoleate hydroperoxides (by 90%) in oxidized HDL. HDL-associated PON, as well as purified PON, were also able to substantially hydrolyze (up to 25%) hydrogen peroxide (H2O2), a major reactive oxygen species produced under oxidative stress during atherogenesis. Finally, we analyzed serum PON activity in the atherosclerotic apolipoprotein E-deficient mice during aging and development of atherosclerotic lesions. With age, serum lipid peroxidation and lesion size increased, whereas serum PON activity decreased. We thus conclude that HDL-associated PON possesses peroxidase-like activity that can contribute to the protective effect of PON against lipoprotein oxidation. The presence of PON in HDL may thus be a major contributor to the antiatherogenicity of this lipoprotein.     

缺血性脑血管病病人血浆LCAT 活性与脂蛋白和红细胞膜脂质成分的相关性研究

目的:探讨缺血性脑血管病（ischemic cerebrovascular disorders,ICVD）病人血浆卵磷脂-胆固醇酰基转移酶（LCAT）活性与脂蛋白和红细胞膜脂质成分含量的相互关系。方法:采用改良的Nagaski酶学方法-外加底物法测定103例ICVD病人和60例健康者血浆LCAT活性,并检测血浆高密度脂蛋白胆固醇（HDL-C）及其亚组分（HDL2-C、HDL3-C）、低密度脂蛋白胆固醇（LDL-C）、载脂蛋白A1和B（apoA1,apoB）、红细胞膜胆固醇（RBCM-C）和红细胞膜磷脂（RBCM-PL）的含量变化。结果:ICVD病人血浆LCAT活性、HDL-C、HDL2-C及apoA1含量明显降低,血浆LDL-C、apoB、RBCM-C及RBCM-C/RBCM-PL比值显著增高,与对照组相比差异有显著性（P<0.05）,血浆LCAT活性分别与HDL-C、HDL2-C及apoA1水平呈正相关（P<0.05、P<0.05、P<0.05）,而与LDL-C（和RBCM-C呈负相关（P<0.05）。结论:ICVD病人脂质代谢异常与血浆LCAT活性降低有关。     

HDL metabolic activities in a boy with lipoprotein lipase deficiency and his family

BACKGROUND: Lipoprotein lipase (LPL) deficiency is a rare autosomal recessively inherited disease characterized by elevated triglyceride, low total cholesterol and quantitative and qualitative alterations of high-density lipoprotein (HDL). The aim of the present study was to explore HDL metabolic activities in a patient with LPL deficiency and in his family (n = 11). MATERIALS AND METHODS: Subjects were divided into four groups: proband (Ser447Stop/Arg170Leu carrier), Ser447Stop carriers, Arg170Leu carriers and silent mutation/wild-type carriers (controls). Cholesterol efflux from Fu5AH cells, lecithin:cholesterol acyltransferase (LCAT), cholesteryl ester transfer protein (CETP), paraoxonase 1 (PON1) and platelet-activating factor acetylhydrolase (PAF-AH) activities were evaluated. RESULTS: Comparison between the proband and the control group revealed that the boy had significantly reduced cholesterol efflux (P < 0.001), conserved LCAT activity (P > 0.05) and increased CETP activity (P < 0.001). As regards antioxidant enzymes, while PON1 activity was higher in the proband than in the controls (P < 0.0001), PAF-AH activity was reduced (P < 0.05). The other groups did not show relevant differences in comparison with controls. CONCLUSIONS: The presence of one mutation was not enough to introduce important modifications in HDL functions. Markedly reduced HDL levels can keep certain normal enzymatic activities, which probably tend to counteract the deleterious effects of LPL deficiency.     

血清不同温育条件对高密度脂蛋白胆固醇的稳定性影响研究

目的 探讨血清高密度脂蛋白胆固醇(HDL-C)在不同温度、时间下的储存稳定性。方法 2015年5月自卫生部北京医院征集健康志愿者10人(男性4人,女性6人,年龄24～59岁),将收集的血清在4℃温育24 h,25℃温育0,1,8和24 h[分别含和不含卵磷脂胆固醇酰基转移酶(LCAT)抑制剂],HPLC法测定血清总胆固醇(TC),总游离胆固醇(TFC),HDL-C以及HDL游离胆固醇(HDL-FC)。使用微软EXCEL软件进行结果分析。结果 血清在4℃温育24 h,造成HDL-FC和HDL-C变化(平均为-6.91%和-2.17%); 25℃温育24 h造成TFC,HDL-FC及HDL-C的变化(平均为-13.70%,-25.88%和-1.53%); 25℃下LCAT抑制剂完全抑制TFC的降低、部分抑制HDL-FC的降低,使HDL-C降低幅度更大。结论 血清贮存可造成胆固醇变化,这种变化取决于LCAT,胆固醇酯转移蛋白(CETP)的活性以及FC在脂蛋白之间的转移。因此,为提高血脂测定结果的准确性,应尽量减少不必要的血清贮存。     

Cholesterol esterification rate and its relation to lipoprotein levels in plasma in normal human pregnancy

The lecithin:cholesterol acyl transfer (LCAT) reaction produces cholesteryl esters and lysolecithin in plasma. The rate of LCAT is related to the plasma lipoprotein concentrations. During pregnancy there are pronounced elevations of the lipid and lipoprotein concentrations. Therefore, we studied the LCAT rate and its relation to the lipid levels in plasma lipoproteins in 19 healthy women before conception, every sixth to eighth week during pregnancy, and 8 weeks after delivery. In the first part of gestation the mean molar LCAT rate (the amount of cholesteryl esters produced during a certain time, in micromoles per liter per hour) remained unchanged, whereas pronounced elevations were seen in the very low-density lipoprotein (VLDL), high-density lipoprotein (HDL), and HDL2 levels. The molar LCAT rate did not increase until the last trimester of pregnancy, when it reached a maximal 20% mean increase simultaneous with the maximal increase of the mean triglyceride and VLDL levels and a slight decline of the HDL2 elevation. The mean fractional LCAT rate (the part of unesterified cholesterol that is esterified during a certain time, in percent per hour) showed a continuous decrease from the fourteenth until the twenty-eighth week, simultaneous with a progressive rise of the mean cholesterol and low-density lipoprotein (LDL) concentrations. During pregnancy the molar LCAT rate was positively correlated to the VLDL concentration and negatively to the HDL2 level, and the fractional LCAT rate was negatively correlated to the LDL concentration.     

Paraoxonase (PON1) activity in patients with subclinical thoracic aortic atherosclerosis

High density lipoprotein (HDL), a powerful antioxidant, protects low density lipoprotein (LDL) particles against oxidative stress. By limiting LDL oxidation, HDL plays an important role in preventing atherosclerosis (AS). The antioxidant effect of HDL is mostly associated with the paraoxonase (PON1) activity. It has been known that increased aortic intima-media thickness (IMT) is an earlier marker AS than carotid IMT. We aimed to investigate the association between thoracic aortic IMT and serum PON1 activity. We studied 133 patients (mean age: 46.3 ± 8 years) who underwent transesophageal echocardiography (TEE) for various indications. The measurements of thoracic aortic IMT by TEE are classified into four grades (1, 2, 3 and 4). Serum PON1 activity was measured spectrophotometrically. Oxidative and anti-oxidative status was evaluated by measuring serum lipid hydroperoxide (LOOH), total anti-oxidant status (TAS). Serum PON1 activity was progressively decreasing from grade 1 IMT to grade 4 IMT (p < 0.001). However, serum LOOH was significantly lower and TAS was significantly higher in patients with grade 1 when compared with other grades. In multiple linear regression analysis, IMT was independently correlated with PON1 activity (β = ?0.495, p < 0.001), TAS level (β = ?196, p < 0.009), age (β = 0.145, p = 0.029) and LDL cholesterol level (β = 0.169, p = 0.009). Decreased PON1 activity was independently associated with the extent of thoracic AS. PON1 activity may play a role in pathogenesis of thoracic AS besides age, TAS and LDL cholesterol levels.     

Alterations of paraoxonase and platelet-activating factor acetylhydrolase activities in patients on peritoneal dialysis.

OBJECTIVE: The more atherogenic lipid profile seen in peritoneal dialysis (PD) patients cannot fully explain the increased incidence of atherosclerosis in this population. Oxidative modification of low-density lipoproteins (LDL) is considered to play a central role in the atherogenic process, whereas high-density lipoprotein (HDL) protects LDL from oxidation. On the other hand, it has been suggested that the LDL and HDL of PD patients are more resistant to oxidation than those of control subjects, while PD-HDL equally protects LDL from oxidation compared to control-HDL. Two HDL-associated enzymes have been shown to protect both LDL and HDL from oxidation: paraoxonase (PON1) and HDL-associated platelet-activating factor acetylhydrolase (HDL-PAF-AH). Furthermore, low PON1 activity and high total plasma PAF-AH concentration, which represents mainly the LDL-associated enzyme, have been shown to be independent risk factors for coronary artery events in the general population. However, there are limited data regarding possible alterations of these enzymes in PD patients. The aim of our study was to examine the possible alterations of PON1 and PAF-AH activities in patients undergoing PD. DESIGN: A cross-sectional study. SETTING: A university medical center. PARTICIPANTS: 56 PD patients of Caucasian origin and 86 matched controls were studied. MEASUREMENTS: In all subjects, serum PON1 activity toward paraoxon (paraoxonase) and phenylacetate (arylesterase), as well as total serum and HDL-PAF-AH activities were measured; PON1 genetic polymorphisms known to influence PON1 activity (Q192R and M55L) were determined. RESULTS: The PD patients exhibited significantly increased serum PON1 (paraoxonase) and PON1 (arylesterase) activities compared to controls, regardless of the PON1 polymorphisms or the levels of HDL cholesterol. Additionally, PD patients had significantly elevated activities of total serum PAF-AH and HDL-PAF-AH, independently of the levels of LDL or HDL cholesterol. The ratio of HDL-PAF-AH/ total PAF-AH, which has recently been suggested to be a potential marker of atherogenicity, was decreased in these patients compared to controls. Moreover, no difference in the prevalence of PON1 polymorphisms between PD patients and controls was found. CONCLUSION: The elevated activities of PON1 and HDL-PAF-AH could explain the increased resistance of PD-HDL to oxidation; the higher activity of total PAF-AH and the decreased HDL-PAF-AH/ total PAF-AH ratio could contribute to the increased incidence of atherosclerosis in these patients.     

瘦素与中国新疆哈萨克族血压水平及相关因素的关系

目的瘦素与高血压的关系研究国内外不多且结果不一致,探讨血清瘦素浓度与新疆哈萨克族(简称哈族)的血压水平及性别、肥胖、体脂、血脂、和空腹胰岛素的关系。方法用放免法检测68例哈族高血压患者和124例哈族健康志愿者的血清瘦素浓度,同时检测血清总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、脂蛋白(a)［LP(a)］、空腹胰岛素(FINS)和体重指数(BMI)、体脂百分含量(Fat%)及腰围/臀围(WHR),并分析血清瘦素浓度与不同血压水平以及性别、BMI、Fat%、WHR和血脂、空腹胰岛素的关系。结果高血压组血清瘦素显著高于对照组(P<0.01),3级高血压血清瘦素显著高于2组高血压(P<0.05),2级高血压组血清瘦素显著高于1级高血压(P<0.05)。血清瘦素与SBP、DBP均呈直线正相关(P<0.01,P<0.05);女性瘦素显著高于男性(P<0.001),肥胖者瘦素显著高于非肥胖者(P<0.05);血清瘦素与TG呈直线正相关(P<0.05),而与TC、HDL-C、LDL-C及LP(a)无关;高血压组空腹胰岛素水平显著高于对照组(P<0.05),且瘦素与FINS水平呈正相关(P<0.01),与胰岛素敏感性指数(ISI)呈负相关(P<0.05)。结论血清瘦素与新疆哈族血压水平相关,与性别和TG有关,且与BMI、Fat%、TG及FINS呈正相关,与ISI呈负相关。     

Lecithin:cholesterol acyl transfer in plasma of normal persons in relation to lipid and lipoprotein concentration.

Information concerning variation in the lecithin:cholesterol acyl transfer (LCAT) rate in normal persons is scanty. We have therefore analyzed the LCAT rate and the lipid and lipoprotein concentrations in the plasma of healthy normolipidemic persons 20-60 years of age, 40 men and 40 women. 10 per decade and sex. Interindividual variation in molar LCAT rate was 57-130 mumol-u(-1)-h-1 (mean +/- 2 S.D.) with no sex difference. Intraindividual variation of molar LCAT rate studied in 8 women and 9 men was shown to be greater than expected from methodological error and was not explainable by the small changes in plasma lipid concentration during the observation period. In the women the molar LCAT rat was lower during the preovulatory phase of the menstrual cycle than during the postovulatory phase. There was positive correlations between the molar LCAT rate and most of the lipid parameters in plasma. By partial correlation analysis a positive correlation was shown between LCAT rate and triglyceride concentration irrespective of other lipid parameters. Keeping triglyceride concentration constant, there was a positive correlation between molar LCAT rate and total phospholipid, unesterified cholesterol, esterified cholesterol, or low-density lipoprotein (LDL) cholesterol concentration. No correlation was found between high-density lipoprotein (HDL) lipid concentration and LCAT rate. Thus in normal subjects there seems to be a direct relation between very low density lipoprotein and LDL lipid concentration and molar LCAT rate but no relation between HDL lipid concentration and LCAT rate.     

64层螺旋CT冠状动脉成像联合血脂动态变化评价冠心病

目的分析血脂动态变化与冠状动脉粥样硬化性心脏病的关系。方法回顾性分析108例怀疑冠心病首次住院病人,所有病人均行64层螺旋CT冠脉成像（CTA）检查,同时行血脂检查。依据CTA结果分4组,对照组（冠脉无狭窄）;轻度（狭窄〈50％）;中度（50％≤狭窄〈75％）;重度（狭窄≥75％）。结果与对照组比较,血总胆固醇（TC）、血三酰甘油（TG）、高密度脂蛋白胆固醇（HDL—C）及低密度脂蛋白胆固醇（LDL—C）均存在明显差异（P〈0．05）。TC、LDL—C在异常组间无显著性差异（P〉0．05）,而TG、HDL—C存在显著性差异（P〈0．05）。结论TC、LDL—C作为冠状动脉粥样硬化发生的始动因素,TG、HDL—C影响冠脉狭窄程度,在粥样硬化演进中可能起主要作用。动态分析血脂变化对评价冠心病具有一定指导意义。     

Influence of high‐density lipoprotein and paraoxonase‐1 on platelet reactivity in patients with acute coronary syndromes receiving clopidogrel therapy

Summary. Background: The paraoxonase activity of the enzyme paraoxonase‐1 (PON‐1) associated with high‐density lipoprotein (HDL) may significantly influence clopidogrel’s antiplatelet and clinical efficacy as a result of its involvement in the clopidogrel biotransformation to the pharmacologically active thiol metabolite. We evaluated the possible relationships of HDL levels as well as PON‐1 activities and the Q192R genotype with clopidogrel’s antiplatelet efficacy in acute coronary syndrome (ACS) patients. Methods and results: The platelet aggregation, P‐selectin expression and platelet/leukocyte conjugates as well as the clopidogrel response variability (evaluated by the VASP phosphorylation test and expressed as platelet reactivity index, PRI) were assessed in 74 ACS patients undergoing percutaneous coronary intervention (PCI) in relation to the PON‐1 Q192R genotype and to serum HDL‐cholesterol levels, and PON‐1 (paraoxonase and arylesterase) activities. Patients were loaded with 600 mg of clopidogrel followed by 75 mg per day. HDL‐cholesterol levels and PON‐1 activities at baseline (before clopidogrel loading) were not altered at 5‐ and 30‐day post‐clopidogrel loading, whereas baseline platelet activation parameters were significantly attenuated. At 5 days, 17 patients were clopidogrel non‐responders (PRI: 64.2 ± 11.1%). HDL‐cholesterol was inversely associated with platelet activation parameters independently on platelet response variability to clopidogrel whereas a negative association between platelet activation parameters and paraoxonase activity was observed in patients adequately responding to clopidogrel but not in clopidogrel non‐responders. Similarly, the platelet activation markers were significantly higher in PON‐1 Q192Q genotype carriers compared with those having one or two R alleles only in patients adequately responding to clopidogrel. Conclusions: PON‐1 is an important determinant of clopidogrel antiplatelet efficacy only in patients adequately responding to clopidogrel. These findings may be clinically important in ACS patients receiving clopidogrel therapy, especially the first days after the episode.     

Hypertension,lipoprotein subclasses and lipid transfer proteins in obese children and adolescents

Background: Obesity-related childhood hypertension is associated with disturbances of serum lipids, but less is known about distribution of lipoprotein subclasses and activities of proteins involved in reverse cholesterol transport in hypertensive obese children. Our objective was to determine low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subclasses distribution and activities of lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) in hypertensive and non-hypertensive obese children.

Methods: A total of 40 hypertensive and 25 non-hypertensive obese children were enrolled. Lipoprotein subclasses were assessed by polyacrylamide gradient gel electrophoresis. LCAT and CETP activities were determined as a rate of formation and a rate of transfer of cholesteryl esters.

Results: Despite of comparable values of serum lipid parameters, a shift toward smaller LDL and HDL subclasses was observed in hypertensive compared to normotensive obese children. Activities of LCAT were similar, but proatherogenic CETP activities were significantly higher in the hypertensive group (p?= 0.036). LCAT/net CETP ratio inversely correlated with relative proportion of small, dense LDL particles (ρ =??0.423; p?= 0.025) in the group with hypertension.

Conclusions: The results of our study demonstrated a tendency toward altered distribution of lipoprotein subclasses in favor of more proatherogenic particles in childhood hypertension. Also, hypertensive obese children had increased proatherogenic CETP activity.