An examination of the effect of combined cyclical hormone replacement therapy on lipoprotein(a) and other lipoproteins

Impact of menopause and diabetes on atherogenic lipid profile: is it worth to analyse lipoprotein subfractions to assess cardiovascular risk in women?

Cardiovascular disease is the leading cause of death in women at advanced age, who are affected a decade later compared to men. Cardiovascular risk factors in women are not properly investigated nor treated and events are frequently lethal. Both menopause and type 2 diabetes substantially increase cardiovascular risk in the female sex, promoting modifications on lipid metabolism and circulating lipoproteins. Lipoprotein subfractions suffer a shift after menopause towards a more atherogenic lipid profile, consisted of hypertriglyceridemia, lower levels of both total high density lipoprotein (HDL) and its subfraction HDL2, but also higher levels of HDL3 and small low-density lipoprotein particles. This review discusses the impact of diabetes and menopause to the lipid profile, challenges in lipoprotein subfractions determination and their potential contribution to the cardiovascular risk assessment in women. It is still unclear whether lipoprotein subfraction changes are a major driver of cardiometabolic risk and which modifications are predominant. Prospective trials with larger samples, methodological standardizations and pharmacological approaches are needed to clarify the role of lipoprotein subfractions determination on cardiovascular risk prediction and intervention planning in postmenopausal women, with or without DM.

The Relationship Between Circulating Fibrinogen and Lipoprotein (a) Levels in Patients With Primary Dyslipidemia

The correlation between 2 predictors of vascular events, plasma fibrinogen and serum lipoprotein (a), was evaluated in patients referred to a specialist clinic because of primary hyperlipidemia. A significant correlation existed between fibrinogen and lipoprotein (a) in nonsmokers but not in smokers. Plasma fibrinogen concentration correlated positively and significantly with serum lipoprotein (a) levels in men nonsmokers without cardiovascular disease and in women nonsmokers with cardiovascular disease. Nonsmoker women without cardiovascular disease had significantly higher plasma fibrinogen (3.63 g/L versus 3.07 g/L, P < .0001) than the corresponding men. Nonsmoker women with and without cardiovascular disease had significantly higher lipoprotein (a) levels than the corresponding groups of men (0.36 versus 0.18 g/L; P = .0015 and 0.40 versus 0.26 g/L; P = .008), respectively. The relationship between fibrinogen and lipoprotein (a) levels alters markedly depending on the population selected. This relationship is influenced by gender, the presence of cardiovascular disease and smoking status.

[Dyslipidemia in women after 50: age, menopause or both?]

A high prevalence of cardiovascular risk factors is reported in postmenopausal women. The objective of this review was to determine whether the effect of the menopause on lipid profile remained after adjusting for age in middle age women. The results of 10 cross sectional studies and nine longitudinal studies added evidence of a worsening effect of the menopause on total cholesterol, LDL cholesterol and triglyceride plasmatic levels. This effect remained after adjustment for age. Menopausal estrogenic deficiency could be an explanation for those results, even if the hormonal replacement therapy effect on the lipid profile remains unclear.

Impact of a New Formulation of Low-Dose Micronised Medroxyprogesterone and 17-beta Estradiol on Lipid Profiles in Menopausal Women

OBJECTIVE

To evaluate the impact of cyclical low-dose micronised medroxyprogesterone (5 mg/day for the last 12 days of each 28-day cycle) in combination with 17-beta estradiol (2 mg/day continuously) on lipid profiles in postmenopausal women treated for 12 months.

DESIGN AND SETTING

Open, noncomparative, prospective study carried out in general practice.

PATIENTS AND RESULTS

98 female patients were enrolled; seven failed to meet entry criteria, 20 withdrew after developing adverse events, three were lost to follow up and one withdrew for personal reasons; 67 (67.3%) completed 12 months' treatment. Levels of total cholesterol (6.42 mmol/L at baseline) fell 8.4% (p = 0.0001) after 12 months' treatment, while total triglycerides (1.39 mmol/L at baseline) increased by 12.2% (p = 0.007), low density lipoprotein cholesterol (4.27 mmol/L at baseline) fell 18.3% (p = 0.0001) and high density lipoprotein (HDL) cholesterol (1.59 mmol/L at baseline) increased by 6.9% (p = 0.0001). The most frequently reported adverse events were menorrhagia, breast tenderness, cervical polyps or cysts, bloating, fatigue or lethargy, influenza or influenza-like syndrome, back pain and headaches.

CONCLUSIONS

Treatment with oral micronised 17-beta estradiol 2 mg/day continuously and medroxyprogesterone 5 mg/day for 12 days of each 28-day cycle lead to changes in lipid profiles in postmenopausal women that had favourable implications for the risk of development of coronary heart disease. The 17-beta estradiol-induced increase in the level of HDL cholesterol was maintained during combination with low-dose cyclical medroxyprogesterone for 12 months.

Distinct lipid/lipoprotein profiles and hormonal responsiveness in nine ethnic groups of postmenopausal Asian women: the Pan-Asia Menopause (PAM) study

BACKGROUND

Lipid/lipoprotein profiles, among other factors, are associated with risk of cardiovascular disease. Because cardiovascular disease varies in Asian countries, we hypothesized that lipid profiles differ in ethnic groups of postmenopausal Asian women. To add to the limited body of information currently available, we also investigated the effects of estrogen/progestin therapy on lipid/lipoprotein profiles in postmenopausal Asian women.

METHODS

The Pan-Asia Menopause (PAM) study was a prospective, randomized, double-blind clinical trial evaluating 1028 postmenopausal women at 22 investigational centers in 11 Asian countries/territories. Subjects were randomly assigned to one of three doses of continuous combined conjugated estrogens (CE)/medroxyprogesterone acetate (MPA): CE/MPA (in mg/day) = 0.625/2.5, 0.45/1.5 or 0.3/1.5. The treatment period, following baseline evaluations, consisted of six continuous 28-day cycles. Analysis of lipid profiles was a secondary objective of the PAM study. Total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), very low density cholesterol (VLDC-C), triglycerides and lipoprotein(a) were analyzed at a central laboratory by state-of-the-art methods.

RESULTS

Mean concentrations of total cholesterol, LDL-C, VLDL-C and triglycerides differed significantly among the nine ethnic groups of postmenopausal women. This difference was independent of body mass index and age, two factors that also influenced lipid/lipoprotein profiles. Mean HDL-C concentrations also differed, but this difference was influenced by body mass index in a weak interaction. All three doses of CE/MPA significantly lowered total cholesterol. Treatment with the high and middle doses significantly lowered LDL-C, and increased HDL-C, VLDL-C and triglycerides. The high dose produced a significant decrease in lipoprotein(a).

CONCLUSIONS

The different lipid/lipoprotein profiles in the nine ethnic groups of postmenopausal Asian women evaluated here suggest a relationship to differences in the prevalence of cardiovascular disease reported for different regions in Asia. However, the reported prevalence data on cardiovascular disease morbidity and mortality in the regions corresponding to the nine ethnic groups are insufficient to allow qualitative comparisons with the lipid profiles shown in our study. The lipid/lipoprotein changes in response to estrogen/progestin therapy observed here are consistent with those reported for Western women.

Relationship between serum lipoprotein(a) concentrations and coronary vasomotion in coronary spastic angina

BACKGROUND

Elevated lipoprotein(a) (Lp(a)) concentrations are reported to impair endothelium-dependent vasodilatation of the epicardial coronary artery. However, the effects on vasomotor abnormalities in coronary spastic angina (CSA) have not been thoroughly investigated.

METHODS AND RESULTS

In the present study 80 sites of spasm (spastic sites) without significant organic stenosis (% diameter stenosis <50%) were assessed in 80 patients with CSA diagnosed by intracoronary ergonovine (EM) test. Spastic sites were divided into 2 groups: Group 1 included 30 sites provoked by the full dose (=50 microg) of EM, and Group 2 included 50 sites provoked with less than 50 microg (34.7+/-8.2 microg). Control subjects (n=22) did not show coronary spasm with the EM test. Serum Lp(a) concentrations were measured in all patients. Group 2 had a significantly greater basal coronary artery tone in the spastic sites than Group 1 (p<0.001). Lp(a) level in Group 2 was significantly higher compared with both the control group and Group 1 (p<0.05 by analysis of variance). Multivariate analysis confirmed that only serum Lp(a) concentration was associated with low-dose EM spasm provocation.

CONCLUSIONS

Serum Lp(a) concentration could be a marker for high disease activity in CSA.

Effects of Intranasal Estradiol Treatment on Serum Lipoprotein(a) and Lipids in Hysterectomized Women

The aim of the present study was to evaluate the effects of intranasal estradiol on lipid metabolism and lipoprotein(a) [Lp(a)] levels. A prospective comparative study was designed: 49 hysterectomized, healthy postmenopausal women received intranasal 17beta-estradiol (E2; 300 microg/day). Blood samples were collected at baseline and at the end of the 3 and 6 months of therapy. After 6 months, the serum levels of total cholesterol, LDL-cholesterol and triglycerides did not show any significant change with intranasal 17beta-E2 therapy. HDL-cholesterol levels at 3 and 6 months of treatment were significantly increased compared with baseline levels (p = 0.031, p = 0.000, respectively). There was a significant change in serum Lp(a) levels at the 6th month (p = 0.003) but not at the 3rd month (p = 0.183) compared with the baseline levels. Further studies are needed to detect whether these changes are significant and permanent or not.

Effect of hormone replacement therapy, tibolone and raloxifene on serum lipids, apolipoprotein A1, apolipoprotein B and lipoprotein(a) in Greek postmenopausal women

The aim of this study was to assess the effect of estrogen, two regimens of continuous combined hormone replacement therapy (HRT), tibolone and raloxffene on serum lipid, apolipoprotein A1 and B and lipoprotein(a) levels in Greek postmenopausal women. A total of 350 postmenopausal women were studied in a prospective open design. Women were assigned to one of the following regimens depending on the presence of risk factors for osteoporosis, dimacteric symptoms and an intact uterus: conjugated equine estrogen 0.625 mg (CEE, n = 34), continuous combined CEE 0.625 mg plus medroxyprogesterone acetate (MPA) 5 mg, (n = 80), continuous combined 17beta-estradiol 2 mg plus norethisterone acetate (NETA) 1 mg (n = 58), tibolone 2.5 mg (n = 83) and raloxifene HCl 60 mg (n = 50). Forty-five postmenopausal women with no indications for HRT served as controls. Total cholesterol (TC), low-density lipoprotein (LDL) cholestrol and high-density lipoprotein (HDL) cholesterol, triglyceride (TG), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and lipoprotein(a) (Lp(a)) levels were assessed in each subject at baseline, and at 6 and 12 months of therapy. All therapy regimens lowered TC levels compared to baseline (4.2-8.0% decrease). This effect was more prominent in the subgoup of women with high baseline TC levels (9.1-20.4% decrease). LDL cholesterol decreased significantly in CEE, CEE/MPA and raloxifene groups (-11.2%, -11.9% and -11.0%, respectively). Hypercholesterolemic women exhibited a steeper decrease in LDL cholesterol (10.6-27.8% in all therapy groups). TG levels increased significantly in the CEE and CEE/MPA groups (23.7% and 21.8%, respectively), while estradiol/NETA had no effect on TG levels. Tibolone decreased TG levels markedly, by 20.6%, while raloxifene had no TG-lowering effect. HDL cholesterol and ApoA1 were increased by CEE and CEE/MPA (HDL cholesterol, 7.4% and 11.8%, respectively; ApoA1, 17.8% and 7.9%, respectively) and decreased by tibolone (HDL cholesterol, -13.6%; and ApoA1, -9.9%). All therapy regimens except raloxifene lowered Lp(a) levels, with tibolone having the more pronounced effect (-13.2 to -29.0%). In conclusion, each therapy regimen had a diferent effect on lipid-lipoprotein levels, exerting favorable and unfavorable modifications. Hypercholesterolemic women seemed to benefit more from the cholesterol-lowering effect of estrogen replacement therapy/HRT. The choice for a particular regimen should be based on individual needs, indications and lipid-lipoprotein profile.

Combined oral estradiol valerate-norethisterone treatment over 3 years in postmenopausal women: effect on lipids, coagulation factors, haematology and biochemistry

OBJECTIVE

To determine the effect of continuous estradiol valerate 2 mg and norethisterone 0.7 mg daily as hormone replacement on lipid profiles, coagulation factors, haematology and biochemistry over 3 years.

METHODS

An open label trial with 107-133 postmenopausal women assessed pre-treatment and at annual visits with extensive lipid and coagulation profiles, and observation of circulatory adverse events. Standard haematology and biochemical profiles were also analysed. Results were compared at point of entry and at 36 months.

RESULTS

Total cholesterol (TC) and HDL and LDL fractions fell significantly (P=0.0001) and there was a significant decline in favourable ratios as well as a rise in VLDL mass (P=0.0001). Lipoprotein (a) (Lp(a)) decreased significantly (P=0.0053). Fibrinogen, free protein, prothrombin time and thrombin increased (P=0.0001) while platelets and KPTT were unchanged. Protein C, antithrombin III and total protein S decreased (P=0.0001) and there was a rise in the frequency of lupus anticoagulant positivity. Significant but small changes were seen in haematology and biochemical parameters although this did not raise safety issues and their clinical significance was uncertain.

CONCLUSION

The direction of lipid and coagulation factors move in competing ways, emphasising the complexity of metabolic change and making interpretation of outcome for venous and arterial thrombosis or atherosclerosis difficult to predict. Eight patients developed thromboembolic or ischaemic events over the 3 year period of this study but these patients had lipid changes normally considered beneficial to cardiovascular disease and coagulation changes not thought to be associated with thromboembolism. Decrease in lipoprotein 'a' levels might be an indicator of long-term decreases in atherosclerotic events.

Update on cardiovascular disease in post-menopausal women

Cardiovascular disease (CVD), and in particular coronary artery heart disease (CAHD), is the leading cause of morbidity and mortality in women. Until recently, most of our knowledge about the pathophysiology of CVD in women - and, subsequently, management guidelines - were based on studies conducted mostly in men. While similar mechanisms operate to induce CVD in women and men, gender-related differences exist in the anatomy and physiology of the myocardium, and sex hormones modify the course of disease in women. Women, more than men, have their initial manifestation of CAHD as angina pectoris; are likely to be referred for diagnostic tests at a more advanced stage of disease, and are less likely than men to have corrective invasive procedures. The overall morbidity and mortality following the initial ischaemic heart event is worse in women, and the case fatality rate is greater in women than in men. Also, the relative impact of impaired vasoreactivity of the coronary artery, increased viscosity of the blood and dysregulation of automaticity and arrhythmia, is greater in women than in men. The most effective means of decreasing the impact of CVD on women's health is by an active approach from childhood to proper principles of healthcare in order to modify the contribution of specific risk factors. The latter include obesity, abnormal plasma lipid profile, hypertension, diabetes mellitus, cigarette smoking, sedentary lifestyle, increased blood viscosity, augmented platelet aggregability, stress and autonomic imbalance. The use of lipid-lowering drugs has not been adequately studied in women but reports from studies conducted mostly in men do predict an advantage also to women. Oestrogen deficiency after spontaneous or medically induced menopause is an important risk factor for CVD and CAHD. Observational and mechanistic data suggest a role for oestrogen replacement after menopause for primary, and possibly secondary, prevention of CVD. However, two recent prospective trials suggest that treatment de novo with hormone replacement of older post-menopausal women after an acute coronary event may not confer cardiovascular protection and may increase the risk of thromboembolic disease. Results of ongoing long-term studies may determine the beneficial role of hormone replacement versus potential risks involved with this treatment.

The mechanisms of thrombotic risk induced by hormone replacement therapy

OBJECTIVES

To review the available information on the action of hormones on the mechanisms involved in thrombotic risk.

RESULTS AND CONCLUSIONS

Thrombosis plays a crucial role in the genesis and progression of both coronary heart disease (CHD) and venous thromboembolic disease (VTED), the two main forms of cardiovascular disease. Two main determinants of the thromboembolic phenotype, hypercoagulable state and altered endothelium, accumulate much of the work performed on the influence of hormones on thrombosis. Information has accumulated mainly for oestrogens, but increasing evidences support a role for progestogens. The sensitivity of each of the three components of the hemostatic balance, the coagulation cascade, the anticoagulant system and fibrinolysis, to oestrogens has been widely examined in the literature. Functional tests suggest that HRT is accompanied by a procoagulant state. Much of the work has concentrated on changes induced on reputable indicators of risk for either CHD or VTED. Distinct indicators of increased coagulability, such as resistance to activated C protein, antithrombin or tissue factor pathway inhibitor have been selected for VTED, whereas factor VII, fibrinogen, and defective fibrinolysis, for CHD. Different states of genetic susceptibility have been involved in both forms of the disease. The status of health of endothelium, defines another scenario for attention in CHD. A long-term anti-atherogenic action of oestrogens, which may be associated with short-term risk in cases of atherosclerosis-induced endothelial dysfunction, may most adequately explain much of the clinical observation. In both CHD and VTED, the procoagulant changes initiate soon after HRT administration.

Effect of hormone replacement therapy on lipids in perimenopausal and early postmenopausal women

OBJECTIVE

To determine the effects of oral sequential hormone replacement therapy (HRT) on lipid-profile in perimenopausal and early postmenopausal women.

METHODS

We performed a single-center, randomized, placebo-controlled trial. The trial was double blind with respect to 17beta-estradiol/desogestrel (17beta-E-D) and placebo and open with respect to conjugated estrogens/norgestrel (CEE-N). A total of 125 healthy perimenopausal and early postmenopausal women, aged 43-58 years, were recruited from the general population in Zoetermeer, the Netherlands. The intervention consisted of 6 months treatment with 1.5 mg 17beta-estradiol/0.15 mg desogestrel (n=53), 0.625 mg conjugated estrogens/0.15 mg norgestrel (n=36) or placebo (n=36). At baseline, cycle 1, 3 and 6, overnight fasting blood samples were obtained in which lipids were determined. We used linear regression analysis to calculate differences in mean change from baseline in lipids in the active treatment groups compared to placebo.

RESULTS

In both treatment groups significant (P<0.05) falls in low-density-lipoprotein (LDL)-cholesterol (17beta-E-D: -7.8% and CEE-N: -8.4%) and lipoprotein(a) (17beta-E-D: -11.7% and CEE-N: -28.3%) were found compared to placebo. Apolipoprotein A1 (17beta-E-D: 6.8% and CEE-N: 7.3%) and HDL-cholesterol (17beta-E-D: 6.4% and CEE-N: 8.0%) significantly increased compared to placebo. No significant changes were found in the other lipids. Mean changes from baseline in total cholesterol, LDL-cholesterol and apolipoprotein B were significantly more pronounced in postmenopausal women compared to perimenopausal women, adjustment for age-differences did not change the results.

CONCLUSION

Treatment of perimenopausal and early postmenopausal women with 17beta-E-D or CEE-N changes their lipid-profile in a potentially anti-atherogenic direction. Changes appear to be more pronounced in postmenopausal women compared to perimenopausal women.

The prediction of body composition in Chinese Australian females

OBJECTIVE

To determine the efficacy of applying specific body composition techniques to, and assess the relationship between body mass index (BMI) and body fat levels for Chinese Australian females.

DESIGN

Statistical comparative analysis of body composition techniques.

SUBJECTS

Australian resident females of Chinese extraction (n=40) (aged 18-45 y, mean 32.5+/-8.0; BMI range 15.7-30.9 kg/m2, mean 21.7+/-3.1 kg/m2, median 20.8 kg/m2).

MEASUREMENTS

Body composition determined using bio-electrical impedance analysis (BIA), the skin-fold equations of Durnin and Womersley (D&W) and a deuterium dilution technique. Body size was calculated as the body mass index (BMI) weight/height(2) (kg/m2).

RESULTS

With a median BMI of 20.8, range 15.7-30.9, an acceptable BMI existed for 87.5% of the subjects (mean (s.d.) 21.7+/-3.1 kg/m2). Percentage fat mass (%FM) from the deuterium dilution technique (mean (s.d.) 35.6+/-6.4) suggested 75% were overweight or obese. %FM from the D&W equation (mean (s.d.) 28.0+/-3.9) and BIA (mean (s.d.) 29.4+/-5.1) also indicated a tendency towards overweight or obese. The deuterium technique was significantly correlated and significantly different to the D&W eqn, r=0.71 P=0.001; and BIA, r=0.77, P=0.001. Bland and Altman analysis indicated that bias existed between the techniques (BIA mean (s.d.)-6.7+/-4.1) and D&W equation mean (s.d.)-6+/-4.5) when compared to the deuterium method.

CONCLUSIONS

Despite a low mean BMI, body fat levels determined by the three methods suggested that, overall, an unsatisfactory body composition existed. The levels of overweight and obesity (%FM>30) were higher than reported in previous research despite a mean BMI lower than the Australian national average. Comparative analysis suggested that the body fat prediction techniques used may be precise but not accurate. Comparative results obtained for the BIA and D&W equation techniques suggest an overestimation of body fat levels for leaner individuals and under estimation for overfat individuals. The results support the notion that accurate determination of body composition and the determination of appropriate body size may require equations developed for specific ethnic populations.

The benefits of niacin in atherosclerosis

Niacin favorably alters all major lipid subfractions at pharmacologic doses. Alone or in combination, it promotes regression of coronary artery disease, decreases coronary events, stroke, and total mortality. Major recent progress in niacin is in four areas. Firstly, recent data indicate that it increases high-density lipoprotein (HDL) and lowers triglycerides and low-density lipoprotein (LDL) by mechanisms different from statins, fibrates, and bile-sequestrants, giving rationale for combination therapy to achieve synergistic effects for complete lipid goal achievement. Secondly, new data on an extended-release preparation of niacin given once nightly indicates that it is as effective and has greater tolerability than immediate-release niacin. Thirdly, preliminary data with a single tablet formulation extended-release niacin and an HMG CoA reductase inhibitor (lovastatin) shows it to be safe and very effective, especially for raising HDL. Finally, emerging evidence indicates that niacin can be used effectively and safely in patients with type 2 diabetes mellitus, who often have low HDL levels.

A comparison of endothelial function in Caucasian and Chinese women before and after the menopause

OBJECTIVE

Arterial endothelial dysfunction is a key atherogenic event that may be related to oestrogen status. We therefore aimed to compare menopause-related changes in endothelial physiology in Chinese and Caucasian females.

METHODS

We studied 40 female subjects; 20 Chinese from a rural region of Southern China (ten premenopausal, aged 20-35 years, and ten postmenopausal, aged 55-66 years), and 20 age-matched Caucasian females from Sydney, Australia. All women had a clinical history, resting blood pressure and fasting lipids measured, and endothelial function assessed. Using high-resolution external vascular ultrasound, brachial artery diameter was measured at rest, after flow increase (causing endothelium-dependent dilatation) and after sublingual glyceryl trinitrate (GTW) (an endothelium-independent dilator).

RESULTS

There was a significant decline in endothelium-dependent dilatation (EDD) comparing Caucasian females from the premenopausal versus postmenopausal groups (8.4+/-2.7% versus 2.7+/-2.9%; P<0.001). In contrast, there was no significant difference in EDD between pre- and postmenopausal Chinese (9.8+/-3.3% versus 8.3+/-1.7%; P=0.22). On multivariate analysis, postmenopausal status was associated with impaired EDD in Caucasian females (P<0.002) independent of serum cholesterol, blood pressure and vessel size. In contrast, EDD in the Chinese females was not significantly influenced by any of these factors. GTW-induced dilatation was also impaired in the older Caucasian females, a finding explained on multivariate analysis by the increased vessel size in this patient group (P=0.03).

CONCLUSION

Menopause is associated with impaired arterial endothelial function in Caucasian but not Chinese women. This suggests possible ethnic differences in menopause-related vascular changes.

Hormone replacement therapy and lipid-lipoprotein concentrations

OBJECTIVE

To evaluate the links between hormone replacement therapy and lipid-lipoprotein concentrations (total cholesterol [T.Ch] triglycerids, high density lipoprotein cholesterol [HDL-C], low density lipoprotein cholesterol [LDL-C] and very low density lipoprotein cholesterol [VLDL-C]) in a total of 6416 postmenopausal women.

STUDY DESIGN

Open prospective longitudinal study. Of the 2184 surgical postmenopausal women, 1102 received conjugated equine estrogen (CEE), and 1082 transdermal estradiol (TDE2). Of the 4232 natural postmenopausal women: 1073 received CEE+medroxyprogesterone acetate (MPA), 1068 CEE+dydrogesterone (DD), 1044 TDE2+MPA, 1047 TDE2+DD. Lipid-lipoprotein concentrations were evaluated by using a SPSS program at 1,2,3,4,5,6,7 years of therapy and cumulatively.

RESULTS

Cumulative evaluation of the data on estrogen only replacement therapy revealed a significant decrease in T.Ch, LDL-C and VLDL-C, and an increase in HDL-C; however, the increase in HDL-C and triglycerids was significantly higher in CEE than TDE2 (P<0.01). Cumulative evaluation of the data on estrogen progestin hormone replacement therapy revealed a significant decrease in T.Ch, LDL-C and an increase in HDL-C for all; however, triglycerides and VLDL levels decreased in TDE2+MPA and TDE2+DD groups (P<0.05).

CONCLUSION

Both the natural and surgical menopause patients were found to have more favorable lipid profiles after treatment with estrogen progesterone combined formulations and estrogen only replacement.

Effect of thyroid hormone replacement on lipoprotein(a), lipids, and apolipoproteins in subjects with hypothyroidism

OBJECTIVE

To study the effect of thyroid hormone replacement on total cholesterol, low-density lipoprotein cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-I and B-100, and lipoprotein(a) [Lp(a)] in subjects with hypothyroidism.

MATERIAL AND METHODS

In 17 patients with clinical primary hypothyroidism, studies were done before and after thyroid hormone replacement therapy. Free thyroxine and thyrotropin were determined by chemiluminescent assay. Total cholesterol and triglycerides were measured by enzymatic methods, and HDL-C was measured after dextran sulfate-MgCl2 precipitation. Apolipoprotein A-I and B-100 were assayed by immunonephelometry. For measurement of Lp(a), we used a sequential sandwich enzyme-linked immunosorbent assay.

RESULTS

After levothyroxine treatment, the mean concentration of thyrotropin decreased from 91.4 to 3.7 microIU/mL, and free thyroxine increased from 0.5 to 1.2 ng/ dL. Total cholesterol, triglycerides, HDL-C, low-density lipoprotein cholesterol, and apolipoprotein A-I and B-100 decreased after thyroid hormone replacement therapy. Lp(a) levels also decreased significantly (P<0.05) after treatment, from a mean of 33.4 to 25.6 mg/dL.

CONCLUSION

Hypothyroidism is associated with an increase in total cholesterol, triglycerides, HDL-C, apolipoprotein A-I and B-100, and Lp(a). A reduction in lipid and lipoprotein levels after thyroid hormone replacement in our study cohort resulted in a less atherogenic profile.

Apolipoprotein B and coronary artery disease in women: a cross-sectional study in women undergoing their first coronary angiography

The association between plasma apolipoprotein (apo) B concentrations and angiographically determined coronary artery disease (CAD) was investigated in women in a cross-sectional study. Stenosis of >60% in 1 or more coronary arteries was classified as CAD+. CAD- was defined as a maximum stenosis of 10% in any coronary artery. Fasting plasma concentrations of apoB, apoA-I, cholesterol (chol), low density lipoprotein cholesterol (LDL-chol), high density lipoprotein cholesterol (HDL-chol), and triglycerides (TGs) were determined. Information on nonlipid risk factors was obtained from questionnaires. CAD+ women (n=160) were older than CAD- women (n=129), 64.0+/-7.8 vs 57.8+/-11.1 years, respectively. CAD+ compared with CAD- women had higher frequencies of diabetes (14.7% vs 5.8%, P=0.05), hypertension (53% vs 37%, P=0.018), and ever-smoking (48% vs 35%, P<0.001). CAD+ women had higher plasma concentrations of apoB (1.48+/-0.32 vs 1.25+/-0.34 g/L, P<0.001), chol (7.01+/-1.19 vs 6.38+/-1.22 mmol/L, P=0.001), LDL-chol (4.74+/-1.09 vs 4.13+/-1.13 mmol/L, P<0.001), and TGs (1.98+/-0.84 vs 1.71+/-0.93 mmol/L, P=0.007) and lower levels of HDL-chol (1.28+/-0.28 vs 1.37+/-1.38 mmol/L, P=0.028). After correction for nonlipid risk factors, apoB, chol, LDL-chol, HDL-chol, and TG were independently related to CAD. In the lowest quartiles of chol, LDL-chol, and TG, CAD+ women had higher apoB concentrations than CAD- women. In contrast, chol, LDL-chol, TG, or HDL-chol levels were not different in any quartile of apoB. ApoB showed the most significant relation with the number of stenotic vessels, and apoB was associated with CAD in the normolipidemic subgroup. In conclusion, apoB was superior to chol, LDL-chol, HDL-chol, TG, and apoA-I in discriminating between CAD+ and CAD-.

Modification of serum apolipoprotein A-I, apolipoprotein B and lipoprotein(a) levels after bisphosphonates-induced acute phase response

Lipoprotein(a) (Lp(a)) is a low density lipoprotein-like particle displaying strong atherothrombotic properties. Although the concentration of Lp(a) in plasma is under strong genetic regulation, there are emerging evidences that several other factors, such as hormonal disorders, acute phase, liver and renal failure may affect its metabolism. The aim of the present study was to investigate whether bisphosphonates, an effectual drug in the treatment of malignant hypercalcemia and Paget's disease of bone, known to induce a concomitant acute phase, may have a significant influence on Lp(a) concentrations. Nine subjects (four men and five women), with plasma Lp(a) concentrations in the range between 6.4 and 17.7 mg/dl, were subjected to a single intravenous infusion of bisphosphonates (7.5 mg of aminohydroxybutylidene and 5.0 mg of aminohydroxylidene), previously dissolved in 250 ml of saline. Lp(a), apo A-I, apo B, C reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured at the baseline and after days one, two, four and seven. CRP, ESR and Lp(a) started to increase after two days from the treatment, reaching statistical significance after day two, four and seven, respectively. Apo B and apo A-I decreased significantly after days one and two, respectively. Although patterns and relative amounts of the increase of CRP were substantially different among the subjects studied, the increase of Lp(a) was more homogeneous; the peak of Lp(a) concentrations was reached only seven days after treatment in the group as a whole, in agreement with previous observations. In univariate regression analysis, significant correlations were found only between apo A-I and ESR, and apo A-I and Lp(a). The present study suggest that Lp(a) behaves as an acute phase protein. Besides, we observed a slight but significant decrease of apo A-I and apo B after administration of bisphosphonates.

Standardization and clinical management of lipoprotein(a) measurements

The present article proposes personal suggestions to improve determinations and clinical interpretation of results of lipoprotein(a) assays. Methods and procedures for sampling and quantification of the various isoforms of lipoprotein(a) in serum, plasma and urine are reviewed with the aim of improving the reliability and reproducibility of results and reinforcing the clinical utility of lipoprotein(a) measurements.

Effects of nandrolone decanoate (Decadurabolin) on serum Lp(a), lipids and lipoproteins in women with postmenopausal osteoporosis

Although lipoprotein(a) (Lp(a)) concentrations are mainly regulated genetically, it has been reported that variations in sex hormone concentrations may have effects on serum Lp(a). We evaluated the effect of nandrolone decanoate, a testosterone-derived synthetic anabolic steroid, on serum Lp(a), lipids and lipoproteins in 19 postmenopausal women who were given parenteral nandrolone decanoate (Decadurabolin) once a week for 3 weeks. At the 4th week, a significant decrease was observed for total cholesterol (p = 0.003), Lp(a) (p = 0.0003), apolipoprotein A-I (apo A-I) (p < 0.0001), and high density lipoprotein-cholesterol (HDL-C) (p < 0.0001). Moreover, a significant decrease in serum albumin concentration (p = 0.002) was concomitantly observed. We conclude that the administration of nandrolone decanoate significantly affects the lipid profile of postmenopausal women, showing controversial effects in terms of cardiovascular risk.