Novel use of the Friedewald formula to tackle anomalous HDL-C results in two cases of paraproteinaemia

OBJECTIVES: We report here two cases of paraproteinaemia with one falsely low and the other dubiously high HDL-cholesterol (HDL-C) results. The spurious results seemed to be related to the nature (IgG or IgM) as well as the concentration of the paraproteins. DESIGN AND METHODS: We have been using an alternative approach to estimate the HDL-C concentration by incorporating into it the LDL-cholesterol (LDL-C) value obtained by direct measurements and by back-calculation based on the time-honored Friedewald equation in these atypical specimens as an interim measure, pending optimization of the Roche direct HDL-C plus assay currently in use in our laboratory. RESULTS: This approach is convenient and does not require sophisticated instrumentation. What we are suggesting is to tackle this analytical problems on HDL-C assay due to paraprotein interference by back-calculating the HDL-C values from the measured LDL-C and triglyceride values using the Friedewald formula and is to be regarded as an alternative way to circumvent the interference issue without the need for more elaborative laboratory procedures. We do not intend to advocate screening every single HDL-C value obtained by the direct method for possible analytical errors using this approach. CONCLUSIONS: The back-calculation for HDL-C based on the Friedewald formula is conceived by the authors as an alternative and relatively simple way to estimate the HDL-C value in the presence of paraprotein interference, in particular when there is a minus HDL-C value or when the result is dubiously high. By the same token, when the measured HDL-C and the calculated HDL-C do not match further investigations would be warranted to safeguard the validity of the reported result. It is also, to the best of our knowledge, the first time extra bands due to the IgM and IgG paraproteins were demonstrated in the lipoprotein electrophoresis plate.     

Plasma vaspin concentrations are decreased in acute coronary syndrome,but unchanged in patients without coronary lesions

Objective

Previous studies suggested that decreased serum vaspin levels were associated with coronary artery disease (CAD). The present study aimed to investigate the association between plasma vaspin levels and different states of CAD.

Design and methods

A total of 162 patients with coronary angiography (CAG) proved that CAD was enrolled. Additional 103 patients complained with “chest discomfort” with negative CAG, and 60 normal subjects were enrolled in this study. The levels of plasma vaspin, adiponectin, clinical parameters, lipid profile and C reactive protein (CRP) were measured.

Results

The levels of plasma vaspin were significantly lower in the CAD group (0.47 ± 0.63 μg/L) than those in the healthy group and CAG (−) group (all p < 0.001). In CAD group, the pos hoc analysis showed that serum vaspin concentration in acute myocardial infarction group (0.21 ± 0.19 μg/L) was significantly lower than that in the unstable angina pectoris group (0.40 ± 0.37 μg/L) (p = 0.012), and serum vaspin concentration in unstable angina pectoris was significantly lower than that in stable angina pectoris group (0.92 ± 0.94 μg/L) (p = 0.013). The plasma vaspin concentration was also negatively correlated with the severity of CAD (1-vessel: 0.86 ± 0.90 μg/L; 2-vessel: 0.36 ± 0.39 μg/L; 3-vessel: 0.21 ± 0.16 μg/L). The plasma vaspin concentration in CAG (−) group with “chest discomfort” (1.93 ± 2.57 μg/L) was similar to the healthy control group (2.18 ± 3.49 μg/L).

Conclusions

The plasma vaspin concentration correlated to the severity of CAD. Furthermore, plasma vaspin has a value of avoiding patients without CAD from unnecessary CAG.     

中药红曲复方制剂降脂作用的实验研究

[目的]探讨中药红曲复方制剂对降低高脂血症模型大鼠血脂水平的疗效。[方法]采用高脂饲料喂养SD大鼠建立预防性高脂血症模型,将实验大鼠分成阴性对照组、模型对照组、阳性对照组、低剂量组、中剂量组和高剂量组。连续灌胃给药30d,观察中药红曲复方制剂对高脂血症大鼠血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)的影响。[结果]与阴性对照组比较,高脂饲料连续喂养30d后,模型对照组大鼠血清TG、TC和LDL-C显著升高(P0.01);与模型对照组比较,给药30d后,阳性对照组TG、TC和LDL-C显著降低(P0.05);低剂量组大鼠血清TG显著降低(P0.05),中剂量组和高剂量组血清TG、TC和LDL-C显著地降低(P0.01);各剂量组大鼠血清HDL-C无统计学差异(P0.05)。[结论 ]中药红曲复方制剂可有效控制并降低血脂水平。     

化痰降浊汤对高脂血症血脂的影响

目的观察化痰降浊汤对高脂血症患者血脂的影响。方法选取60例患者,予化痰降浊汤口服(药物组成:泽泻15 g,山楂10 g,陈皮20 g。水煎取汁150 mL。消毒,灭菌,4℃保存备用),1次/d,连续30 d。结果服用化痰降浊汤后,总胆固醇、三酰甘油、低密度脂蛋白胆固醇指标均下降,高密度脂蛋白胆固醇指标上调。结论化痰降浊汤具有调节血脂的作用。     

Fortification of flours with folic acid reduces homocysteine levels in Brazilian women

Our hypothesis is that the fortification of flour with folic acid contributes to the reduction of plasma homocysteine (Hcy). We conducted a cross-sectional study covering 2 periods, before and after fortification (2002-2003 and 2008-2009, respectively), to assess the influence of the consumption of corn and wheat flours prefortification and postfortification with folic acid on Hcy levels and other biomarkers. In the total, 93 women (38 prefortification and 55 postfortification) were included. Levels of lipids and glucose, total Hcy and serum folate, and cobalamin were determined using commercial kits by colorimetric method, competitive immunoassay, and chemiluminescence, respectively The participants' average age was 48.1 ± 9.5 years for the prefortification group and 39.1 ± 4.1 years for the postfortification group (P < .001) but adjusted statistical tests by age. Both groups presented obesity class 1. In the prefortification group, 71.1% (n = 27) of women had a dietary intake of folate, which was lower than the current recommended for adults (<400 μg/d), whereas in the postfortification group, only 16.4% (n = 9) of women had lower intakes than recommended. In the prefortification group, 42.1% (n = 16) of women had hyperhomocysteinemia (>10 mmol/L) compared with only 9.1% (n = 5) in the postfortification group. Moreover, statistically significant differences were found between the 2 groups in total cholesterol, high-density lipoprotein, triglycerides, and dietary fiber. Our findings corroborate the hypothesis that fortification of wheat and corn flours with folic acid can possibly be associated with lower concentrations of plasma Hcy, providing probable greater cardiovascular protection in this group.     

Nonlinear relation between alcohol intake and high-density lipoprotein cholesterol level: results from the Copenhagen City Heart Study

BACKGROUND: It has been suggested that the level of high-density lipoprotein cholesterol (HDL-C) in the blood can be used as a marker of recent alcohol intake. However, before using HDL-C as a predictor of alcoholism, the relation between alcohol intake and HDL-C in the entire range of consumption must be explored. Most studies model the relation between alcohol intake and HDL-C linearly, although a threshold effect is expected. The objective of this study was to evaluate the shape of the relation between intake of alcohol and HDL-C and to determine whether there are differential effects of beer, wine, and spirits on HDL-C and whether they remain after adjusting for total alcohol. METHOD: The relation between alcohol intake and HDL-C was investigated by means of generalized additive models using data from the Copenhagen City Heart Study. RESULTS: A nonlinear effect of alcohol improved the model fit significantly, and the nonlinearity of alcohol was highly significant in both men and women. The relation was concave: HDL-C was stable in men and women who drank more than approximately 35 and 20 drinks per week, respectively. We found a significant nonlinear term of wine on HDL-C in men after adjustment for total alcohol intake. CONCLUSIONS: There was a concave relation between alcohol intake and HDL-C, indicating a threshold effect of alcohol on HDL-C. The association between wine and HDL-C in men after adjusting for total alcohol intake may be due to residual lifestyle confounding.     

动脉粥样硬化性脑梗死患者血脂分析

目的探讨血脂异常血症与动脉粥样硬化性脑梗死的关系。方法指标TCH、TG采用酶法检测，HDL—C、LDL—C采用磷钨酸-镁沉淀法检测。结果患病组与对照组血脂四项检测结果比较差异有显著性（P〈0．01）。结论血脂异常与动脉粥样硬化性脑梗死的发生有密切的关联，是动脉粥样硬化性病变形成的必要因素，注意脂类的合理摄入是预防和治疗动脉粥样硬化性脑梗死的重要方面。     

TC和TG均正常的人群高／低密度脂蛋白胆固醇水平分析

目的了解总胆固醇（TC）和甘油三酯（TG）均处于合适范围的人群高密度脂蛋白胆固醇（HDL-C）和低密度脂蛋白胆固醇（LDL-C）水平，提高对HDL-C和LDL-C检测的重视，从而较全面地筛选出血脂异常。方法根据2007年《中国成人血脂异常防治指南》标准，从学校4021名健康体检人群中筛选出1587例TC和TG均处于正常水平的人群，进行HDL-C和LDL—C的统计分析。结果正常TC和TG人群中，HDL—C降低占6．24％，LDL-C边缘升高检出率为12．35％，LDL-C升高检出率为1．64％。其中男性分别为8．82％、16．00％、2．77％；女性分别为2．12％、6．54％、0．65％，男性均高于女性（p〈0．01），女性在50岁以后HDL-C和LDL—C异常的检出率明显上升。结论TC、TG两项指标均处于合适范围的人群仍可能存在HDL—C的降低和LDL-C的边缘升高或升高。临床医师和实验室人员应高度重视HDL-C和LDL—C的检测。     

Effect of atorvastatin upon platelet activation in hypercholesterolemia, evaluated by flow cytometry

Hyperlipidemia is a well established risk factor for cardiovascular disease and atherothrombotic events, in which platelet activation also plays a significant role. However, very few studies have addressed platelet activation in hypercholesterolemia, the potential effect of lipid lowering drugs upon platelet hyperfunction, and the question of whether changes in the latter are correlated to normalization of plasma lipids. This study used whole blood flow cytometry to assess in vivo and in vitro platelet activation in a group of 33 patients with hypercholesterolemia, and also the ex vivo effect of atorvastatin (20 mg/day) upon such activation. A control group of 40 normolipidemic volunteers matched in terms of age, sex and added risk factors to the patient group was used. The results showed that hypercholesterolemic patients had in vivo a significantly greater percentage of GPIIb/IIIa- and phosphatidylserine-positive platelets compared with the control group (4.62+/-3.51% and 2.58+/-1.19% versus 2.73+/-1.08% and 1.54+/-0.68%, respectively). In vitro response of CD62 expression to thrombin was also greater in the patients than in the controls (92.51+/-6.00% versus 89.63+/-10.72%, p<0.05). Atorvastatin therapy normalized platelet hyperfunction in the patients studied and reduced GPIIb/IIIa response to ADP (from 82.65+/-6.43% to 75.84+/-4.89%, p<0.01). A significant correlation can be seen between such normalization and the decrease in plasma levels of total and LDL cholesterol.     

Contrasting prevalence of and demographic disparities in the World Health Organization and National Cholesterol Education Program Adult Treatment Panel III definitions of metabolic syndrome among adolescents

OBJECTIVE: To determine prevalence of metabolic syndrome (MS) among adolescents by using definitions from the National Cholesterol Education Program Adult Treatment Panel III (NCEP) and World Health Organization (WHO) guidelines and to compare the populations identified by these definitions. STUDY DESIGN: School-based, cross-sectional study of 1513 black, white, and Hispanic teens who had a fasting morning blood sample drawn and a physical examination. RESULTS: Overall, the prevalence of NCEP-defined MS was 4.2% and of WHO-defined MS was 8.4%. MS was found almost exclusively among obese teens, for whom prevalence of NCEP-defined MS was 19.5% and prevalence of WHO-defined MS was 38.9%. Agreement between definitions was poor (kappa statistic=0.41). No race or sex differences were present for NCEP-defined MS. However, nonwhite teens were more likely to have MS by WHO criteria (RR, 1.40; 95% CI, 1.04, 1.87), and MS was more common among girls if the WHO-based definition was used (RR, 1.26; 95% CI, 1.08, 1.88). CONCLUSIONS: Among adolescents, obesity is a powerful risk for MS. Important demographic and clinical differences exist in the typology of MS, depending on the definition. Such discrepancies suggest that the concept of a common pathologic syndrome or etiologic mechanism underlying MS as defined by these guidelines may be flawed.