Effects of estrogen on susceptibility to oxidation of low-density and high-density lipoprotein in postmenopausal women

Objective: To investigate the effects of estrogen on the susceptibility to oxidation of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) in postmenopausal women. Methods: A total of 23 postmenopausal women were treated with 0.625 mg of conjugated equine estrogen daily for 3 months. Blood samples were obtained before and after therapy. Plasma levels of total cholesterol and triglyceride and the concentrations of cholesterol, triglyceride, phospholipid in LDL and HDL were determined enzymatically and the levels of apolipoprotein A-I, A-II in HDL and apolipoprotein B in LDL were measured by turbidimetric immunoassay. The isolated LDL and HDL were incubated at 37°C for 24 h with CuSO₄ 5 μmol/l and the lipid peroxide concentration of LDL and HDL was measured. Results: Estrogen significantly reduced the plasma level of total cholesterol and significantly increased the plasma level of triglyceride. The LDL concentrations of cholesterol, phospholipid and apolipoprotein B were significantly decreased following estrogen therapy. The triglyceride level of LDL did not change significantly. The HDL concentrations of cholesterol, triglyceride, phospholipid and apolipoprotein A-I and A-II were all significantly elevated after estrogen therapy. Estrogen significantly inhibited the peroxidation of LDL at 50–2000 μg of LDL protein (14.17±4.17–11.49±1.42 nmol/200 μg of LDL protein, P<0.001) and of HDL (4.49±1.74–3.37±1.24 nmol/200 μg of HDL protein, P<0.03) induced by their incubation in the presence of CuSO₄. Conclusions: Estrogen inhibited the susceptibility of LDL and HDL to oxidative modification and favorably affected lipid metabolism by reducing the number of LDL particles and increasing the number of HDL particles in plasma that were resistant to oxidation.     

Response of lipid, lipoprotein-cholesterol, and electrophoretic characteristics of lipoproteins following a single bout of aerobic exercise in women

The effects of a single session of moderate intensity (65% VO(2)max) aerobic exercise expending 500 kcal of energy on serum lipid and lipoprotein-cholesterol concentrations and the electrophoretic characteristics of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles were determined in 11 sedentary, eumenorrheic, premenopausal women immediately prior to, and 24 and 48 h following exercise. Repeated measures analysis of variance revealed significant reductions in triglyceride (25.0%), HDL-cholesterol (10.9%), and HDL(3)-cholesterol (11.9%) concentrations at 48 h post-exercise. Despite these changes in lipid and lipoprotein-cholesterol concentrations, no significant changes were observed in peak LDL or HDL particle sizes or in the distribution of cholesterol within the LDL and HDL subfractions. Accordingly, it appears that a single session of moderate intensity aerobic exercise expending 500 kcal (2,092 kJ) of energy promotes reductions in triglyceride, HDL-C, and HDL(3)-C concentrations without concomitantly affecting the electrophoretic characteristics of LDL and HDL particles in this sample of women.     

Regional adipose tissue and lipid and lipoprotein levels in HIV-infected women

BACKGROUND: HIV infection and antiretroviral therapy are associated with dyslipidemia, but the association between regional body fat and lipid levels is not well described. METHODS: Multivariable linear regression analyzed the association between magnetic resonance imaging-measured regional adipose tissue and fasting lipids in 284 HIV-infected and 129 control women. RESULTS: Among African Americans, HIV-infected women had higher triglyceride (116 vs. 83 mg/dL; P < 0.001), similar high-density lipoprotein (HDL; 52 vs. 50 mg/dL; P = 0.60), and lower low-density lipoprotein (LDL; 99 vs. 118 mg/dL; P = 0.008) levels than controls. Among whites, HIV-infected women had higher triglyceride (141 vs. 78 mg/dL; P < 0.001), lower HDL (46 vs. 57 mg/dL; P < 0.001), and slightly lower LDL (100 vs. 107 mg/dL; P = 0.059) levels than controls. After adjustment for demographic and lifestyle factors, the highest tertile of visceral adipose tissue (VAT) was associated with higher triglyceride (+85%, 95% confidence interval [CI]: 55 to 121) and lower HDL (-9%, 95% CI: -18 to 0) levels in HIV-infected women; the highest tertile of leg subcutaneous adipose tissue (SAT) was associated with lower triglyceride levels in HIV-infected women (-28%, 95% CI: -41 to -11) and controls (-39%, 95% CI: -5 to -18). After further adjustment for adipose tissue, HIV infection remained associated with higher triglyceride (+40%, 95% CI: 21 to 63) and lower LDL (-17%, 95% CI: -26 to -8) levels, whereas HIV infection remained associated with lower HDL levels (-21%, 95% CI: -29 to -12) in whites but not in African Americans (+8%, 95% CI: -2 to 19). CONCLUSIONS: HIV-infected white women are more likely to have proatherogenic lipid profiles than HIV-infected African American women. Less leg SAT and more VAT are important factors associated with adverse lipid levels. HIV-infected women may be at particular risk for dyslipidemia because of the risk for HIV-associated lipoatrophy.     

Sleep duration and sleep complaints and risk of myocardial infarction in middle-aged men and women from the general population: the MONICA/KORA Augsburg cohort study

STUDY OBJECTIVES: To examine gender-specific associations between sleep duration and sleep complaints and incident myocardial infarction (MI). DESIGN: Cohort study. SETTING: A representative population sample of middle-aged subjects in Germany. PARTICIPANTS: The study was based on 3508 men and 3388 women (aged 45 to 74 years) who participated in one of the 3 MONICA (Monitoring trends and determinants on cardiovascular diseases) Augsburg surveys between 1984 and 1995, who were free of MI and angina pectoris at baseline and were followed up until 2002. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: A total of 295 cases of incident MI among men and 85 among women occurred during a mean follow-up period of 10.1 years. Compared with women sleeping 8 hours, the multivariable adjusted hazard ratio (HR) of MI among women sleeping < or =5 hours was 2.98 (95% CI, 1.48-6.03), and among women sleeping > or =9 hours 1.40 (95% CI, 0.74-2.64); the corresponding HRs among men were 1.13 (95% CI, 0.66-1.92) and 1.07 (95% CI, 0.75-1.53). In multivariable analysis the relative risk of an incident MI for men and women with difficulties maintaining sleep was 1.12 (95% CI, 0.84-1.48) and 1.53 (95% CI, 0.99-2.37), respectively, and for men and women with difficulties initiating sleep the relative risk was 1.16 (95% CI, 0.82-1.63) and 1.30 (95% CI, 0.81-2.06), respectively. CONCLUSIONS: Modest associations between short sleep duration and difficulties maintaining sleep and incident MI were seen in middle-aged women but not men from the general population.     

Short Sleep Duration as a Risk Factor for Hypercholesterolemia: Analyses of the National Longitudinal Study of Adolescent Health

Study Objectives:

To explore the relationship between sleep duration in adolescence and hypercholesterolemia in young adulthood. Experimental sleep restriction has been shown to significantly increase total cholesterol and LDL cholesterol levels in women. Short sleep duration has been found in cross sectional studies to be associated with higher total cholesterol and lower HDL cholesterol levels. Sleep deprivation could increase the risk for hypercholesterolemia by increasing appetite and dietary consumption of saturated fats, decreasing motivation to engage in regular physical activity, and increasing stress and resultant catecholamine induced lipolysis. No previous published population studies have examined the longitudinal relationship between sleep duration and high cholesterol.

Design:

Multivariate longitudinal analyses stratified by sex of the ADD Health using logistic regression.

Setting:

United States nationally representative, school-based, probability-based sample.

Participants:

Adolescents (n = 14,257) in grades 7 to 12 at baseline (1994-95) and ages 18 to 26 at follow-up (2001-02).

Measurements and Results:

Among females, each additional hour of sleep was associated with a significantly decreased odds of being diagnosed with high cholesterol in young adulthood (OR = 0.85, 95% CI 0.75-0.96) after controlling for covariates. Additional sleep was associated with decreased, yet not statistically significant, odds ratios for hypercholesterolemia in males (OR = 0.91, 95% CI 0.79-1.05).

Conclusions:

Short sleep durations in adolescent women could be a significant risk factor for high cholesterol. Interventions that lengthen sleep could potentially serve as treatments and as primary preventative measures for hypercholesterolemia.

Citation:

Gangwisch JE; Malaspina D; Babiss LA; Opler MG; Posner K; Shen S; Turner JB; Zammit GK; Ginsberg HN. Short sleep duration as a risk factor for hypercholesterolemia: analyses of the National Longitudinal Study of Adolescent Health.     

Associations of sleep duration and quality with serum and hepatic lipids: The Netherlands Epidemiology of Obesity Study

Short and long sleep duration and poor sleep quality may affect serum and hepatic lipid content, but available evidence is inconsistent. Therefore, we aimed to investigate the associations of sleep duration and quality with serum and hepatic lipid content in a large population‐based cohort of middle‐aged individuals. The present cross‐sectional study was embedded in the Netherlands Epidemiology of Obesity (NEO) study and consisted of 4260 participants (mean age, 55 years; proportion men, 46%) not using lipid‐lowering agents. Self‐reported sleep duration and quality were assessed using the Pittsburgh Sleep Quality Index questionnaire (PSQI). Outcomes of this study were fasting lipid profile (total cholesterol, low‐density lipoprotein [LDL]‐cholesterol, high‐density lipoprotein [HDL]‐cholesterol and triglycerides), postprandial triglyceride (response) levels, and hepatic triglyceride content (HTGC) as measured with magnetic resonance spectroscopy. We performed multivariable linear regression analyses, adjusted for confounders and additionally for measures that link to adiposity (e.g. body mass index [BMI] and sleep apnea). We observed that relative to the group with median sleep duration (≈7.0 hr of sleep), the group with shortest sleep (≈5.0 hr of sleep) had 1.5‐fold higher HTGC (95% confidence interval [CI]: 1.0‐2.2). The group with PSQI score ≥ 10 had a 1.1‐fold (95% CI: 1.0‐1.2) higher serum triglyceride level compared with the group with PSQI ≤ 5. However, these associations disappeared after adjustment for BMI and sleep apnea. Therefore, we concluded that previously observed associations of shorter sleep duration and poorer sleep quality with an adverse lipid profile, may be explained by BMI and sleep apnea, rather than by a direct effect of sleep on the lipid profile.     

Serum lipid, lipoprotein and apolipoprotein changes in gestational diabetes mellitus: a cross-sectional and prospective study.

AIMS: To compare serum lipid, lipoprotein and apolipoprotein concentrations during and six to 12 months after pregnancy in control and diabetic women. METHODS: The serum lipid, lipoprotein and apolipoprotein concentrations were measured in 20 women with gestational diabetes mellitus (GDM) and 22 women with normal glucose tolerance (controls) during the third trimester of pregnancy and six to 12 months after delivery. RESULTS: During pregnancy the women with GDM had higher serum triglyceride (mean (95% confidence interval (CI)), 2.91 (2.22-3.51) v 2.1 (1.75-2.52)) but lower low density lipoprotein (LDL) cholesterol concentrations compared with controls (mean (SD), 3.08 (1.2) v 4.01 (1.1). Total cholesterol, high density lipoprotein (HDL) cholesterol and apolipoprotein concentrations were not significantly different between the two groups. After pregnancy, total cholesterol, HDL cholesterol, triglyceride, and apolipoprotein A1 and B decreased in a parallel manner, resulting in lower concentrations, comparable between the two groups. LDL cholesterol concentrations decreased after pregnancy in the controls (mean (SD), 4.01 (1.1) v 2.69 (0.6)) but not in those with GDM (3.08 (1.2) v 2.72 (0.7)). The change in lipid concentrations was not related to change in weight. CONCLUSION: Development of diabetes during pregnancy induces a state of dyslipidaemia characterised by elevated triglyceride concentrations, as seen in other insulin resistance states. However, GDM seems to blunt the increase in LDL cholesterol during pregnancy and this requires further investigation. Whether the changes in lipoprotein metabolism in GDM are significant for the health status of the mother and the foetus requires further study.     

Adverse effects of danazol prophylaxis on the lipid profiles of patients with hereditary angioedema

BACKGROUND: Hereditary angioedema (HAE) is a rare disorder caused by the deficiency of the C1-inhibitor gene (C1INH) . Patients experience recurrent bouts of edema, which can occur in almost any region of the body. As regards the treatment of the disease, danazol (an attenuated androgen) is used, among other agents, for long-term prophylaxis. OBJECTIVE: The aim of this study was to investigate the possible adverse effects of danazol on serum lipid profile, as well as to ascertain whether danazol treatment is associated with an increased risk of atherosclerosis. METHODS: Serum concentrations of total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides, apolipoprotein A-I, apolipoprotein B-100, and lipoprotein(a) were compared between danazol-treated patients with HAE and 2 control groups (ie, patients who did not receive long-term danazol prophylaxis and untreated healthy subjects). RESULTS: Serum concentrations of HDL ( P = .0002 and P < .0001) and apolipoprotein A-I ( P = .0015 and P < .0001) were significantly lower, whereas LDL ( P = .0129 and P = .0127) and apolipoprotein B-100 ( P = .0456 and P = .0013) were higher in the danazol-treated patients compared with the 2 control groups, respectively. No significant difference was found in total cholesterol, triglyceride, or lipoprotein(a) levels. Patients who received danazol had an 11.6 (95% CI, 2.7-49.7) times higher risk for abnormally low HDL levels and a 4.4 (95% CI, 1.2-16.0) times lower risk for high LDL concentrations. CONCLUSIONS: Our findings indicate that the long-term use of danazol is associated with an increased risk for early atherosclerosis in patients with HAE. Consequently, monitoring of HDL and LDL levels at regular intervals is recommended during follow-up.     

Influence of serum paraoxonase polymorphism on serum lipids and apolipoproteins

One hundred and sixty-three healthy Chinese subjects of both sexes were studied for serum paraoxonase (PON) polymorphism, and levels of lipids and apolipoproteins in order to examine effects of PON alleles on these parameters. The level of serum triglyceride was significantly higher in high activity allele (PON*B) compared with that in low activity allele (PON*A) in both sexes (P less than 0.01). The subjects with PON A had significantly higher LDL cholesterol (P less than 0.05) and lower Apo A-II and ApoB levels. The influence of serum paraoxonase on serum lipids was estimated further by Spearman's rank correlation. In the males, there was a significant negative correlation of serum paraoxonase activity with total (P less than 0.05) and LDL (P less than 0.01) cholesterol levels, and positive correlation with HDL cholesterol and Apo A-II levels (P less than 0.05). Serum paraoxonase activity had a high positive correlation with serum triglyceride levels in both sexes (P less than 0.001). Serum ApoB level had a positive correlation with the enzyme activity only in females (P less than 0.01). The allelic effect of PON on these parameters was studied by multiple regression analysis. The high activity allele (PON*B) was associated with higher serum triglyceride level (P less than 0.001) and ApoB (P less than 0.001), while it had lowering influence on total cholesterol (P less than 0.05) and LDL cholesterol (P less than 0.005) in men. The average allelic effect of PON was found to be about 22% for serum triglycerides, 11% for LDL cholesterol, 14% for Apo A-II and 19% for Apo B in the present study. This study suggests a possible significant role of serum paraoxonase alleles in the metabolism of serum lipids and apolipoproteins.     

免疫吸附疗法治疗高脂血症疗效观察

目的 观察低密度脂蛋白(LDL)免疫吸附疗法对高脂血症的治疗效果.方法73例高脂血症患者接受LDL免疫吸附治疗.比较1次治疗前后各项血脂指标的变化.部分病例1个月后复查血脂各项指标.总结LDL免疫吸附疗法的安全性和副作用.结果①所有患者经1次LDL免疫吸附后血甘油三脂、胆固醇和低密度脂蛋白均有明显下降(p<0.01).高密度脂蛋白略有下降(p>0.05).患者临床症状改善.②治疗后1个月复查,血脂各项指标恢复到治疗前水平(p>0.05).③3例药物治疗不能控制的乳糜微粒血症患者经LDL免疫吸附治疗后血脂明显下降,但仍达不到正常范围.其中1例治疗后继续服用原降脂药物,药物疗效较前提高.④30例患者治疗过程出现低血压.结论LDL免疫吸附能有效降低血甘油三脂、胆圃醇和低密度脂蛋白水平,对高密度蛋白无明显影响.1次治疗所能维持血脂于低水平的时间短暂.部分患者临床症状改善.低血压是主要并发症.     

内源性高甘油三酯血症患者血浆VLDL、LDL及HDL对血凝的影响

目的：研究内源性高甘油三酯血症(HTG)患血浆极低密度脂蛋白(VLDL)、低密度脂蛋白(LDL)及高密度脂蛋白(HDL)是否发生了氧化修饰及其对血凝的影响。方法：对2l例内源性高甘油三酯血症患与2l例年龄性别相近的正常人的血脂、脂质过氧化物进行了分析。用一次性密度梯度超速离心法分离血浆VLDL、LDL及HDL，测定这三种脂蛋白的234nm光吸收、相对电泳迁移率(REM)和硫代巴比妥酸反应物质(TBARS)，分别将这三种脂蛋白加入由正常人新鲜混合血浆构成的反应系统中，按试剂盒分别测定凝血酶原时间(PT)及活化部分凝血酶原时间(APIT)。结果：内源性HTG患血浆TG含量平均升高2．73倍，HDLC下降l.7l倍，同时LPO升高1．22倍;HTG组VLDL、LDL及HDL的REM、234nm光吸收值、TBARS含量均较对照组显增加(P＜0．01)，表明内源性HTG患血浆VLDL、LDL及LDL均发生了氧化修饰生成Ox—VLDL、Ox-LDL.PT及APTT在分别加入HTG组的VLDL、LDL及HDL后均比加入相应正常组脂蛋白明显缩短(P均＜0．05)。相关分析表明，HTG组血浆VLDL及HDL相对电泳迁移率(REM)与PT呈负相关(P＜0．01)。结论：HTG患血浆VLDL、LDL及HDL发生了氧化修饰，并使PT及APTT明显缩短。     

A prospective study of sleep duration and mortality risk in women

STUDY OBJECTIVES: It is commonly believed that 8 hours of sleep per night is optimal for good health. However, recent studies suggest the risk of death is lower in those sleeping 7 hours. We prospectively examined the association between sleep duration and mortality in women to better understand the effect of sleep duration on health. DESIGN: Prospective observational study. SETTING: Community-based. PARTICIPANTS: Women in the Nurses Health Study who answered a mailed questionnaire asking about sleep duration in 1986. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Vital status was ascertained through questionnaires, contact with next of kin, and the National Death Index. During the 14 years of this study (1986-2000), 5409 deaths occurred in the 82,969 women who responded to the initial questionnaire. Mortality risk was lowest among nurses reporting 7 hours of sleep per night. After adjusting for age, smoking, alcohol, exercise, depression, snoring, obesity, and history of cancer and cardiovascular disease, sleeping less than 6 hours or more than 7 hours remained associated with an increased risk of death. The relative mortality risk for sleeping 5 hours or less was 1.15 (95% confidence interval [CI], 1.02-1.29) for 6 hours, 1.01 (95% CI, 0.94-1.08), for 7 hours, 1.00 (reference group), for 8 hours, 1.12 (95% CI, 1.05-1.20), and for 9 or more hours 1.42 (95% CI, 1.27-1.58). CONCLUSIONS: These results confirm previous findings that mortality risk in women is lowest among those sleeping 6 to 7 hours. Further research is needed to understand the mechanisms by which short and long sleep times can affect health.     

Effects of apolipoprotein A-IV genotype on glucose and plasma lipoprotein levels

The effects of apolipoprotein (apo) A-IV genotype on serum glucose, total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, triglyceride and glucose concentrations were ascertained in a population of 373 men and 361 women with a mean age of about 57 years. Subjects were evaluated at entry into a lifestyle intervention program. Apolipoprotein A-IV genotype variations at residues 347 and 360 were examined, as these mutations affect the sequence of apo A-IV, a major protein constituent of intestinal triglyceride-rich lipoprotein and HDL. With regard to the apo A-IV 360 mutation, 16.4% of the females and 13.4% of the males carried the apo A-IV 2-allele, almost entirely in the heterozygous state. No effect of the apo A-IV 1/2 genotype was observed in either men or women on total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride, the total cholesterol (TC)/HDL ratio, or on A-I, A-IV and apo B levels. This was also the case for the apo A-IV 347 mutation. However, women with the apo A-IV 360 1/2 genotype had significantly (p < 0.005) higher glucose levels (105.5 mg/dl) compared with the 1/1 wild-type (94.0 mg/dl). All analyses were also adjusted for age, body mass index, medications, alcohol use and cigarette smoking. The prevalence of the 347 mutation was somewhat higher than the 360 mutation, with 29% of the females and 32.0% of the males being heterozygous for this mutation, and 3.9% of the females and 5.4% of the males being homozygous for this mutation. These data are consistent with the concept that the apo A-IV 360 and 347 genotypes have no significant effect on apo A-IV levels and other lipid parameters in either gender. However, apo A-IV 360 1/2 genotype did have a significant effect on serum glucose levels in women.     

Plasma lipids and lipoproteins and essential hypertension

In recent years there have been many studies demonstrating a correlation between increased arterial blood pressure and altered lipid profiles, and there has been an especially positive correlation between high cholesterol levels and blood pressure. There are differences between the various reports that are important. In our study the lipid distribution in 105 hypertensive patients with mild or moderate arterial hypertension according to WHO criteria without clinically or ultrasonographically apparent atherosclerosis was compared to the lipid distribution in 65 age-matched healthy persons. On the epidemiological level a significant, positive association was found between LDL serum levels (P 0.001), Apo B serum levels (P 0.001), serum triglyceride levels (P 0.05) and VLDL serum levels (P 0.01) and arterial hypertension. However, in contrast to recent reports, no significant difference was found between total serum cholesterol levels in normotensives and hypertensives, and there was no difference in HDL serum levels. No evidence could be found for a significant increase in lipoprotein (a) serum levels in hypertensives.Abbreviations LDL low density lipoprotein - VLDL very low density lipoprotein - HDL high density lipoprotein - Apo B 100 apolipoprotein B 100 - Apo A I apolipoprotein A I Correspondence to: H. Vetter     

Multiple lipid scoring system for prediction of coronary heart disease risk: application to African Americans

BACKGROUND: Clinicians often obtain a panel of lipids but then only use low-density-lipoprotein (LDL) cholesterol to make clinical decisions. We previously described the multiple lipid measure, a strategy that integrates information about seven lipid measures. Our current inquiry uses the multiple lipid measure to create a scoring system and validates that system in a second cohort. METHODS AND RESULTS: A scoring system that uses total cholesterol, high-density lipoprotein (HDL) cholesterol, LDL cholesterol and triglycerides was developed and tested. African-American participants of the Atherosclerosis Risk in Communities (ARIC) Study were used to validate the multiple lipid measure score. For nonsmokers, scores > or = 2 had a hazard ratio of 4.25 (95% CI 1.92-9.40) compared to reference scores of < or = -3 in adjusted survival analysis predicting incident coronary heart disease risk in the ARIC. The best conventional single lipid measure for nonsmokers was LDL cholesterol. Compared to LDL cholesterol <100 mg/dl, those with LDL cholesterol > or = 160 mg/dl had a hazard ratio of 2.31 (95% CI 1.13-4.75). For current smokers, the best conventional lipid measure was the total cholesterol/HDL cholesterol ratio, which was similar in predictive ability to the multiple lipid measure score. However, the multiple lipid measure score predicted an additional 10% of the cohort at risk compared to the total cholesterol/HDL cholesterol ratio. CONCLUSIONS: The use of the multiple lipid scoring system improves the assessment of incident coronary heart disease risk and may have utility for clinicians in integrating lipid values.     

Low serum LDL cholesterol levels and the risk of fever, sepsis, and malignancy

Lipid lowering therapy of serum LDL cholesterol (LDL) has proved beneficial in reducing cardiovascular morbidity and mortality. Lately the recommended target LDL level in very high risk patients was reduced to <70 mg/dl, raising the question of what the price of such a low level will be. To elucidate this concern, we investigated the associations of low serum LDL cholesterol levels (< or = 70 mg/dl) and the incidences of fever, sepsis, and malignancy. Retrospective analysis of 203 patients' charts was carried out. Patients were divided into 2 groups: Group 1 (n = 79) had serum LDL levels < or = 70 mg/dl, while Group 2 (n = 124) had levels >70 mg/dl. The first group demonstrated increased odds of hematological cancer by more than 15-fold (OR 15.7, 95% CI 1.78-138.4, p = 0.01). Each 1 mg/dl increase in LDL was associated with a relative reduction of 2.4% in the odds of hematological cancer (OR 0.976, 95% CI 0.956-0.997, p = 0.026). Low LDL levels also increased the odds of fever and sepsis between the groups (OR 5.3, 95% CI 1.8-15.7, p = 0.02). In summary, low serum LDL cholesterol level was associated with increased risks of hematological cancer, fever, and sepsis.     

猕猴脑动脉硬化造型过程中血清脂质的变化

高脂高胆固醇喂养幼年(2—4岁)和成年(10—13岁)雄性猕猴16—17个月,并辅以服用甲基琉氧嘧啶。实验结果,发现第二个月的胆固醇水平超过250mg%,并持续到实验结束。低密度脂蛋白—胆固醇(LDL—C),伴随着总胆固醇升高而升高,甘油三酯(TG)和高密度脂蛋白—胆固醇(HDL—C)变化不大。幼年和成年组之间无显著性差异。     

The relationship between serum lipids,nucleation time,and biliary lipids in patients with gallstones

Summary The relationship between biliary lipids, cholesterol saturation index, nucleation time, and serum lipids was studied in a group of 45 gallstone patients (10 male, 35 female; age 50.1 ±14.5 years). Bile was obtained by direct fine-needle puncture of the gallbladder under local anesthesia and sonographic monitoring. No significant correlation between the serum lipids and either the cholesterol saturation index or total biliary cholesterol levels was observed. We found a positive correlation between the nucleation time and serum triglycerides content (r = 0.45, p = 0.0018) and a negative correlation between nucleation time and biliary cholesterol level (r = –0.38, p = 0.009). The fatty acids derived from the triglycerides are primarily resynthesized to phospholipids in the liver. When the supply of free fatty acids exhausts the metabolic capacity of the liver as, for example, in fat-rich diets, triglycerides accumulate in the liver cells and may possibly be excreted in the bile. Free fatty acids stimulate mucin hypersecretion in the gallbladder. This mucosal hypersecretion has been assigned a significant role in the formation of gallbladder stones. We also found a positive correlation between the total biliary bile acids and serum high density lipoprotein (HDL)-cholesterol in patients with a rapid nucleation time (r = 0.50, p = 0.0128). This supports the findings of other researchers, which suggests that HDL-cholesterol is devoted primarily to bile acid synthesis. In patients with a short nucleation time, the cholesterol saturation index, total lipid concentration, biliary cholesterol, mean age, and biliary bile acids were statistically different in comparison with patients with a prolonged nucleation time.Abbreviations CSI cholesterol saturation index - CT computer tomography - HU Hounsfield units - NT nucleation time - TLC total lipid concentration - LDL/HDL low/high density lipoproteins - VLDL very low density lipoproteins     

ApoE polymorphism may determine low-density lipoprotein cholesterol level in association with obesity and metabolic syndrome in postmenopausal Korean women

Purpose

We investigated how serum low-density lipoprotein (LDL) level is related to various isoforms of apolipoprotein (ApoE) polymorphism in association with obesity and metabolic syndrome.

Materials and Methods

We gathered total 332 sample of postmenopausal Korean women and analyzed ApoE isoforms, serum lipid level including LDL, blood pressure, fasting glucose, and anthropometry. The relationship between ApoE isoforms and serum lipid level, metabolic syndrome, and obesity was investigated.

Results

Six ApoE isoforms were found, ApoE2 [E2/2 (n=1), E2/3 (n=54), E2/4 (n=14)], ApoE3 (E3/3, n=200), ApoE4 [E3/4 (n=55), and E4/4 (n=8)]. The prevalence of metabolic syndrome and obesity showed higher ApoE3 isoform than that of other isoforms. In additon, ApoE3 isoform was related to higher serum LDL and total cholesterol level than to ApoE2 isoform. The odds ratio of having the highest LDL cholesterol quartile in ApoE3 with obesity, compared to ApoE2 without obesity, was 3.46 [95% confidence interval (CI); 1.07-11.14, p=0.037], and odds ratio of ApoE3 with metabolic syndrome compared to ApoE2 without metabolic syndrome was 5.06 (95% CI; 1.14-22.29, p=0.037). Serum LDL cholesterol was positively associated with obesity or metabolic syndrome in ApoE3 isoform.

Conclusion

This study suggests that obesity or metabolic syndrome risk should be effectively managed in ApoE3 isomform groups to reduce serum LDL in postmenopausal Korean women.     

Effects of short-term melatonin administration on lipoprotein metabolism in normolipidemic postmenopausal women

OBJECTIVE: To investigate the effects of short-term administration of melatonin on lipoprotein metabolism in normolipidemic postmenopausal women. METHODS: Fifteen such women received 6.0 mg melatonin daily for 2 weeks. Blood was sampled before and after treatment. We measured concentrations of total cholesterol and total triglyceride in the plasma, as well as the levels of cholesterol, triglyceride, and protein in the very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). Plasma apolipoprotein levels were determined by immunoturbidimetric assay. Activities of lipoprotein lipase, hepatic triglyceride lipase, and lecithin cholesterol acyltransferase were also determined by enzymatic analysis. RESULTS: Melatonin administration significantly increased the plasma levels of triglyceride by 27.2% (P < 0.05), of VLDL-cholesterol by 37.2% (P < 0.01), of VLDL-triglyceride by 62.2% (P < 0.001), and of VLDL-protein by 30.0% (P < 0.05). However, the plasma total cholesterol level and the concentration of lipid and protein in LDL and HDL were not significantly affected. Melatonin significantly increased the plasma levels of apolipoprotein C-II by 29.5% (P < 0.005), of C-III by 17.1% (P < 0.001), and of E by 7.6% (P < 0.05). The plasma levels of apolipoprotein A-I, A-II, and B were not altered. Melatonin significantly inhibited the activity of lipoprotein lipase by -14.1% (P < 0.05), but did not significantly affect the activities of hepatic triglyceride lipase or of lecithin cholesterol acyltransferase. CONCLUSIONS: Findings indicate that melatonin increases the plasma level of VLDL particles by inhibiting the activity of lipoprotein lipase, but may not affect the plasma levels of LDL and HDL particles in postmenopausal women with normolipidemia.