Coronary artery disease with normal lipids and low coronary artery calcium in two women with high lipoprotein(a)

We present 2 patients with elevated levels of lipoprotein (a) and significant coronary artery disease despite having little coronary artery calcification. Clinicians should be aware that patients with elevated lipoprotein (a) may have important coronary artery disease with low coronary artery calcification scores.     

Triglyceride and lipoprotein (a) are markers of coronary artery disease severity among postmenopausal women

Objective: After menopause, some women manifest coronary artery disease (CAD) with highly variable angiographic severity. For these women, postmenopausal appearing of some CAD risk factors may have differently influenced the CAD risk and severity. In this study, we attempt to unravel differences in the frequency or intensity of CAD risk factors among postmenopausal women with different angiographic severity. Methods: We studied 182 postmenopausal women (64±6 years) who underwent coronary angiography to investigate thoracic pain. Subjects with no detectable coronary lesions at angiography were recruited to the non-obstructive group and patients with CAD were grouped in one-vessel or multi-vessel groups. We compared clinical variables as the body mass index (BMI), age at menopause, age, hypertension, diabetes and cigarette smoking, and lipid measurements as plasma levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein (apo) A1, apo B and lipoprotein(a) (Lp(a)). Results: Comparing to the non-obstructive group, Lp(a) was twofold higher in the one-vessel group and threefold higher in the multi-vessel group and triglycerides were 34% higher in the one-vessel group and 50% higher in the multi-vessel group. No further difference was found among the three groups. After multivariate logistic regression analysis, triglyceride (odds ratio: 1.01; P=0.0013) and Lp(a) (odds ratio: 1.006; P<0.0001) were independently indicative of the presence of obstructive CAD. Conclusion: We found that both Lp(a) and triglycerides constitute useful markers of CAD severity among postmenopausal women.     

Apolipoprotein(a) phenotypes and lipoprotein(a) concentrations in patients with hyperthyroidism

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL) particle in which apolipoprotein B-100 (apoB) is attached to a glycoprotein called apolipoprotein(a) [apo(a)]. Apo(a) has several genetically determined phenotypes differing in molecular weight, to which Lp(a) concentrations in plasma are inversely correlated. High plasma levels of Lp(a) are associated with atherosclerotic diseases. It is therefore of interest to study whether factors other than the apo(a) gene locus are involved in the regulation of Lp(a) concentrations. We measured plasma concentrations of Lp(a) and other lipoproteins and determined apo(a) phenotypes in 31 patients with hyperthyroidism, before and after the patients had become euthyroid by treatment. The mean concentration of LDL cholesterol rose from 2.67 to 3.88 mmol/l (P<0.01), apoB rose from 0.79 to 1.03 g/l (P<0.01), and the median Lp(a) concentration increased from 9.74 to 18.97 mg/dl (P<0.01) on treatment. Lp(a) concentrations were inversely associated to the size of the apo(a) molecule both before (P< 0.01) and after treatment (P<0.01). The increase in Lp(a) was significant patients with high molecular weight apo(a) phenotypes (n = 9; P<0.01) and in patients with low molecular weight apo(a) phenotypes (n=16; P< 0.01), but not in those with apo(a) null types (n = 6; P = 0.5). The low levels LDL cholesterol and apoB in untreated hyperthyroidism may result from increased LDL receptor activity. The increase in Lp(a) levels were not correlated with the increase in LDL cholesterol or apoB. Most other clinical evidence indicates that the LDL receptor is not important in Lp(a) catabolism, and we suggest that the low Lp(a) levels seen in thyroid hormone excess are caused by an inhibition of Lp(a) synthesis.Abbreviations Lp(a) lipoprotein(a) - apo(a) apolipoprotein(a) - apoB apolipoprotein B-100 - LDL low-density lipoprotein - HDL high-density lipoprotein - TG triglycerides - T ₄ thyroxine - T ₃ triiodothyronine - TSH thyrotropin     

Increased levels of lipoprotein(a) in non-smoking aortic dissection patients

OBJECTIVES: To investigate lipoprotein(a) (Lp(a)) serum levels in patients with aortic dissection and the influence of smoking on the level of Lp(a) in aortic dissection patients. METHODS: An age-and sex-matched case-control study was conducted. Lp(a) levels in patients with aortic dissection (n = 52) and healthy subjects (n = 104) were studied. The strength of associations between Lp(a) serum levels and aortic dissection was assessed by means of multivariate logistic regression analysis. RESULTS: Patients with aortic dissection had significantly higher Lp(a) serum levels (median, 17.6 mg/dl; range, 6.4-88.7 mg/dl) compared to healthy individuals (median, 12.4 mg/dl; range, 4.9-26.4 mg/dl) (p = 0.005). The Lp(a) concentration in non-smoking patients with aortic dissection (median, 19.1 mg/dl, range, 10.5-88.7 mg/dl) significantly surpassed that of the smoking patients with aortic dissection of comparable age (median, 10.7 mg/dl; range, 6.4-22.1 mg/dl) (p < 0.0001). Multivariate analysis confirmed an independent association between Lp(a) and aortic dissection in the non-smoking population (p = 0.001). CONCLUSIONS: Serum Lp(a) level is significantly elevated in non-smoking patients with aortic dissection independently of other cardiovascular risk factors. Therefore, determination of Lp(a) levels may be important in identifying subjects at risk of aortic dissection among nonsmokers.     

脂蛋白(a)基因单核苷酸多态性与钙化性主动脉瓣疾病及冠心病的关系

目的 探讨脂蛋白(a)[Lp(a)]基因单核苷酸多态性(SNP)与钙化性主动脉瓣膜疾病(CAVD)、冠心病(CHD)的相关性。方法 前瞻性研究。纳入2018年1-12月天津市胸科医院心内科CAVD或CHD住院患者248例,根据心脏超声多普勒、冠状动脉造影或冠状动脉CT检查结果分为两组:CAVD组101例、CHD组147例;同时选取2018年3-12月天津市胸科医院体检中心排除CAVD或CHD的171位健康体检者为对照组。检测各组Lp(a)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)、载脂蛋白A(ApoA)、载脂蛋白B(ApoB)等生化指标,采用SNaPshot SNP分型技术对Lp(a)基因rs7770628、rs6415084、rs10455872三个位点进行基因分型;采用二元logistic回归分析不同基因型及Lp(a)水平对钙化性主动脉瓣疾病及冠心病发病的影响,采用线性回归分析不同基因型及ApoB水平对Lp(a)水平的影响。结果 三组间比较,患者BMI和饮酒史差异均无统计学意义(P值均＞0.05),性别、年龄、吸烟史、糖尿病史、高血压病史差异均有统计学意义(P值均＜0.05)。Lp(a) 检测值在对照组、CAVD组、CHD组分别为23.6(9.4,48.6)、37.2(16.5,79.6)、46.7(21.5,104.6)nmol/L,三组间比较差异有统计学意义(H=13.337,P<0.01);LDL值各组分别为(2.74±0.80)、(3.07±0.81)、(3.14±1.18)mmol/L,三组间差异有统计学意义(F=3.662,P<0.05);HDL值各组分别为(1.24±0.93)、(1.18±0.30)、(1.09±0.33 )mmol/L,三组间比较差异有统计学意义(F=4.281,P<0.05);ApoA值各组分别为(1.42±0.25)、(1.30±0.26)、(1.26±0.26) g/L,三组间比较差异有统计学意义(F=7.339,P<0.01);ApoB检测值各组分别为0.97(0.82, 1.10)、1.04(0.87, 1.26)、1.12(0.88, 1.31)g/L,三组间比较差异有统计学意义(H=3.948,P<0.05)。Lp(a)基因rs7770628位点对照组、CAVD组、CHD组TT基因型分别为130(76.0%)、75(74.3%)、103(70.1%),CT基因型分别为36(21.1%)、23(22.8%)、40(27.2%),CC基因型分别为5(2.9%)、3(2.9%)、4(2.7%),三组间比较差异无统计学意义(F=1.718,P＞0.05);Lp(a)基因rs6415084位点对照组、CAVD组、CHD组TT基因型分别为5(2.9%)、2(2.0%)、4(2.7%),CT基因型分别为33(19.3%)、20(19.8%)、32(21.8%),CC基因型分别为133(77.8%)、79(78.2%)、111(75.5%),三组间比较差异无统计学意义(F=0.551,P＞0.05);Lp(a)基因rs10455872位点对照组、CAVD组、CHD组AA基因型分别为171(100%)、99(98.0%)、147(100%),AG基因型分别为0(0.0%)、2(2.0%)、0(0.0%),三组间比较差异无统计学意义(P=0.058)。经logistic回归分析,与对照组相比, CAVD组及CHD组的Lp(a)水平更高,其差异有统计学意义,但未发现Lp(a)基因rs7770628及rs6415084两个位点的基因分布频率的差异有统计学意义(P>0.05)。线性回归结果表明,rs7770628以及rs6415084两个基因位点的基因分布均与Lp(a)水平升高有关。rs10455872位点只有2例SNP基因型为AG,且皆出现于CAVD组。结论 Lp(a)基因rs7770628、rs6415084位点的基因分布均与Lp(a)的升高有关,Lp(a)高表达与CAVD以及CHD患病具有相关性。     

Apolipoprotein E phenotype and lipoprotein(a) in familial hypercholesterolaemia implication for lipoprotein(a) metabolism

The mechanisms regulating plasma levels of lipoprotein(a) [Lp(a)] are largely unknown. A two- to three-fold increase in Lp(a) levels in patients with familial hypercholesterolaemia (FH) has implied that LDL receptor activity may be an important factor in determining plasma Lp(a) levels, as it is in determining low-density lipoprotein (LDL) cholesterol concentration. Common apolipoprotein E (apoE) variants also affect plasma LDL cholesterol levels. We therefore examined the effect of the common apoE variants on plasma Lp(a) levels in 149 patients with heterozygous FH. Patients with the apoE₂ allele (n = 11) had significantly higher plasma levels of LDL cholesterol compared to those with a apoE₃E₃ phenotype, while patients with the apoE₄ isoform had similar levels. However, there was a significant effect of the apoE₂ allele in lowering Lp(a) levels, compared to the apoE₃E₃ group. The median Lp(a) concentration in patients possessing an apoE₂ isoform was 13.1 mg/dl below the median, while in those with an apoE₄ allele the median Lp(a) levels were 4.13 mg/dl higher. There was a marked inverse correlation between plasma Lp(a) and LDL cholesterol concentration in the FH patients carrying the apoE₂ allele. Our data imply that difference in Lp(a) levels observed between FH patients with different apoE isoforms does not result from altered clearance of Lp(a) via the LDL receptor pathway, and suggest that apoE mediated hepatic up-take, or conversion, of remnant particles may be determining Lp(a) production rate.Abbreviations apo apoprotein - CHD coronary heart disease - FH familial hypercholesterolaemia - HDL high-density lipoprotein - LDL low-density lipoprotein - Lp(a) lipoprotein(a)     

类风湿性关节炎患者的血清脂蛋白a水平与炎症指标相关性分析

目的 通过对类风湿性关节炎(RA)患者组与对照组(正常健康者)脂蛋白a(Lp-a)与脂代谢水平的比较,分析RA患者血清中的Lp-a水平与系统性炎症进展的风险相关性.方法 选取30例RA患者(血清类风湿因子阳性)与30例正常健康者,年龄为25～80岁,性别分布相同,采集血样并检测其脂代谢水平(Lp-a、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)和极低密度脂蛋白胆固醇(VLDL-C))与炎症反应指标(肿瘤坏死因子α(TN F-α)、白细胞介素6(IL-6)和C反应蛋白(CRP)),对数据进行统计学分析.结果 与对照组比较,RA患者组的血清Lp-a水平显著增高(P＜0.001),HDL-C水平显著降低(P＜0.05),而TC、TG、LDL-C与VLDL-C水平则无明显变化,差异均无统计学意义(P＞0.05).同时,RA患者组的TNF-α、IL-6及CRP水平较对照组均显著增高(P＜0.05),且TNF-α与Lp-a水平的升高有相关性(r=0.753,P＜0.001).结论 RA患者常伴有高水平的Lp-a,且Lp-a水平的升高与RA患者的全身性炎症反应增强具有相关性,Lp-a水平可作为RA患者的风险评价指标.     

Lipoprotein (a), low-density,intermediate-density lipoprotein,and blood pressure in a young male population

Summary Both hypercholesterolemia and hypertension are risk factors for atherosclerotic vascular disease, and elevated cholesterol levels occur more frequently than expected in patients with hypertension. Elevated levels of intermediate-density lipoproteins (IDL) and low-density lipoproteins (LDL) were shown to be atherogenic, and LDL, comprising the major cholesterol-carrying fraction in human plasma, are structurally related to lipoprotein (a) [Lp(a)], a further risk factor for atherosclerosis. In the present study we investigated 200 male employees (mean age 26±7 years) to determine whether the relationship of IDL and Lp(a) to systemic blood pressure is similar to the reported correlations between total and LDL cholesterol and systemic blood pressure. To this end blood pressure was measured several times in each individual, and lipids, lipoprotein-cholesterol, apolipoprotein B (apo B), and Lp(a) were determined in fasting serum. IDL cholesterol and apo B, the main protein component of IDL and LDL correlated with blood pressure. However, levels of Lp(a) correlated neither with systolic or diastolic blood pressure nor with lipoprotein cholesterol, body weight, or age. Although IDL and Lp(a) are considered lipoprotein risk factors for atherosclerosis, levels of Lp(a), unlike IDL, are not related to blood pressure, body weight, or age. Our data suggest different metabolic and pathophysiological mechanisms of the risk factors, IDL, LDL, and Lp(a).Abbreviations VLDL very low density lipoprotein - IDL intermediate-density lipoprotein - LDL low-density lipoprotein - ApoB Apolipoprotein B - Lp(a) lipoprotein (a) - BMI body mass index Dedicated to Prof. Dr. N. Zöllner on the occasion of his 70th birthday     

Effect of low-density lipoprotein buoyant density and cholesterol content on the formation of lipoprotein(a) particles

Lipoprotein(a) [Lp(a)] is a unique lipoprotein which resembles low-density lipoprotein (LDL) both in lipid composition and the presence of apolipoprotein B-100 (apo B-100). Lp(a) is, however, distinguishable from LDL by the presence of an additional glycoprotein apolipoprotein(a) [apo(a)], which is covalently attached to apo B-100 by a single disulfide bond. It is now generally accepted that Lp(a) assembly is a two-step process in which the initial non covalent interaction between apo(a) and apo B-100 is mediated by the weak lysine binding sites present in kringle IV types 6, 7 and 8 of apo(a). In the present study, we have investigated the effect of LDL heterogeneity on Lp(a) assembly in a group of 111 individuals. The three parameters of LDL composition assessed in this study were the cholesterol content, the apo B content, and the relative flotation rate (a measure of LDL buoyancy and thus size). We found no correlation between the size of LDL particles and the extent of Lp(a) formation; a weak negative correlation was observed between cholesterol content of LDL and Lp(a) formation (P=0.042). This may suggest a role for free (i. e., surface-associated) cholesterol in the ability of LDL to form Lp(a) particles. Received: 1 June 2001 / Accepted: 2 July 2001     

Dramatic lowering of very high Lp(a) in response to niacin

We describe a patient with markedly elevated lipoprotein(a) (Lp(a)) without any other lipid abnormalities. After a myocardial infarction, she was treated with combination of extended-release niacin and statin. An 88% reduction in Lp(a) was observed during 5 years of treatment, which is much better response than usually reported.     

Elevated lipoprotein(a) levels in patients with acute myeloblastic leukaemia decrease after successful chemotherapeutic treatment

Summary Twenty-two patients with acute myeloblastic leukaemia (AML) were studied to investigate disease-associated changes in lipid metabolism. Lipoprotein (a) [Lp(a)] levels were found to be elevated at the time of diagnosis (median 23 mg/dl; 41% of patient group had levels greater than 25 mg/dl) and diminished after successful chemotherapeutic treatment in 9 of 10 cases, with a maximum decrease from 56 to 10 mg/dl. In contrast, reduced levels of total cholesterol, low density lipoprotein (LDL) and high density lipoprotein (HDL) (medians 137, 87 and 20 mg/dl, respectively) were observed at the time of diagnosis. Cholesterol and HDL levels increased in all 10 and LDL in 9 cases in which complete remission was achieved. These data suggest that the catabolism of LDL-cholesterol might be even more enhanced than assumed to date. Furthermore, it indicates that the Lp(a) level in acute myeloblastic leukaemia is influenced either directly or indirectly by the leukaemic blasts.Abbreviations AML acute myeloblastic leukaemia - Lp(a) lipoprotein (a) - LDL low density lipoprotein - HDL high density lipoprotein - FAB French-American-British - CALGB cancer and leukaemia group B - CR complete remission - TG triglycerides - VLDL very low density lipoprotein - RIA radioimmunoassay - apo(a) apoprotein (a) - HMG-CoA reductase 3-hydroxy-3-methylglutaryl coenzyme A reductase Supported by the Volkswagen Stiftung with a grant to A.N.     

脂蛋白(a)[Lp(a)]的增高与妊高征

目的探讨脂蛋白(a)Lp(a)与妊高征之间的关系.方法应用ELISA法测定29例非妊高征孕妇(非妊高征组)及19例妊高征患者(妊高征组)的血清Lp(a)水平.结果(1)妊高征组血清Lp(a)水平为(394.5895±210.717)mg/L,高于非妊高征组(180.1896±123.221)mg/L,两组间比较,差异有显著性(P＜0.01).(2)Lp(a)最高值发生于子痫患者.结论Lp(a)与妊高征关系密切,Lp(a)的增高与妊高征之间很可能存在因果关系.     

Relationship between blood pressure reactions on an ergometric and an emotional stress test

Summary The relationship between blood pressure reactions on an ergometric and an emotional stress test was studied in a population of 62 normotensive subjects. Significant correlations for systolic (r=0.34,p=0.004) and diastolic (r=0.30,p=0.01) blood pressure were found.It is concluded that 1) there is a individual-specific blood pressure reactivity, 2) Hypertension is closely related to the individualspecific systolic blood pressure reactivity for it is known that hypertensives exhibit stronger systolic blood pressure reactions on both stressors.     

Morphological detection and quantification of lipoprotein(a) deposition in atheromatous lesions of human aorta and coronary arteries

Summary Lipoprotein(a), as an atherogenic particle, represents an independent risk factor for coronary heart disease. In the present study the morphological distribution of apoprotein (a) and apoprotein B within the arterial wall is described. Apoprotein B, a constituent of very low-density lipoprotein, low-density lipoprotein and lipoprotein(a) has previously been demonstrated in atheromatous lesions. Lipoprotein(a) possesses an additional protein, designated apoprotein (a). Autopsy material (n=74) from the left coronary artery and from the thoracic aorta has been examined by means of immunohistochemistry and both apoprotein (a) and apoprotein B were detected, primarily associated with the extracellular matrix and accumulating in lesions in the arterial wall. The staining pattern for both antigens was almost always found to be congruent, suggesting that the detection of (a)-antigen has to be attributed at least in part to the presence of lipoprotein(a). It is concluded that both low-density lipoprotein and lipoprotein(a) have an important role in the pathogenesis of atherosclerosis.     

Serum lipoprotein (a) levels in chronic renal failure and liver cirrhosis patients. Relationship with atherosclerosis

This study was carried out to investigate the relationship between lipoprotein (a) levels and the development of atherosclerosis in chronic renal failure (CRF) patients with the possible role of the liver. Serum Lp (a) levels were measured in samples from 20 CRF patients on hemodialysis (HD), 20 liver cirrhosis (LC) patients, 20 patients having both CRF and LC and undergoing HD, and 20 normal control subjects. Renal function (blood urea nitrogen (BUN) and creatinine), hepatic function (transaminases (ALT and AST), alkaline phosphatase (ALP) and total bilirubin) investigations and serum cholesterol were carried out for all the subjects enrolled in this study. Serum Lp (a) concentration in CRF patients without LC was 87.25 +/- 6.17 mg/dl, which was significantly higher than all the investigated groups (P < 0.001). Lp (a) concentration in patients with both CRF and LC was 24.65 +/- 1.98 mg/dl, which was not significantly different from the controls, but was significantly higher than that in the subjects with LC only (P < 0.001) where the latter group had significantly low Lp (a) values (11.1 +/- 0.99) relative to all the other groups (P < 0.001). Lp (a) correlated positively with cholesterol in all groups except the LC subjects, but did not correlate with age, or renal function in both CRF groups.