Influence of menopause on serum lipids and lipoproteins

The influence of the menopause on serum lipids and lipoproteins was examined longitudinally at 6-week intervals for 2–3 years in pre-menopausal women undergoing the menopause. Serum lipid and lipoprotein profiles were also examined cross-sectionally in 4 groups of pre-menopausal, perimenopausal and post-menopausal women, who were followed up longitudinally at 3-monthly examinations for 1–2 years. The results covering 1360 examinations and 270 woman-years are reported here.

Serum concentrations of total cholesterol (P = 0.001), low-density-lipoprotein (LDL) cholesterol (P = 0.001) and triglycerides (P < 0.05) increased significantly as a consequence of the menopause and all increases occurred within 6 months of cessation of menstrual periods. High-density-lipoprotein (HDL) cholesterol decreased significantly (P < 0.05) as a consequence of the menopause, but the decline occurred gradually over the 2 years preceding cessation of menses. In addition to the menopausal changes, serum concentrations of total cholesterol and LDL-cholesterol increased gradually in the pre-menopausal and post-menopausal years, but were significantly related to biological age only in the pre-menopausal groups (P < 0.05). Serum triglycerides and HDL-cholesterol levels remained virtually unchanged in the pre-menopausal as well as the post-menopausal groups and were only influenced by the actual menopause.

Serum lipids and lipoproteins are thus significantly altered as a consequence of the menopause. The result is a more atherogenic lipid profile which may partly explain the increased risk of cardiovascular disease observed in post-menopausal women.     

类风湿关节炎患者血清中高密度脂蛋白的水平检测与意义

目的分析类风湿关节炎(Rheumatoid Arthritis,RA)患者体内高密度脂蛋白(HDL-C)的水平与疾病活动度的关系。方法选取RA患者158例,化学沉淀法检测患者血清中HDL-C水平,同时收集患者的其它临床指标,包括C反应蛋白(CRP)、红细胞沉降率(ESR)、类风湿因子(RF)及抗环瓜氨酸肽(CCP)抗体。通过查体评估患者的压痛关节数(Tender joint count,TJC),肿胀关节数(Swollen joint count,SJC),视觉疼痛评分(Visual analogue scale,VAS),并通过标准公式根据ESR来评价患者的28个关节疾病活动度(Disease activity score in 28 jointsusing ESR,DAS28-ESR)水平。结果在总体RA患者中,其HDL-C水平与其CRP,ESR水平呈负相关,女性患者HDLC水平较男性患者高,复治患者HDL-C水平较初治患者高。对于初治患者,HDL-C与患者的炎症水平呈负相关,血清学阳性的患者HDL-C水平较血清学阴性的患者高,对于女性血清学阳性的患者而言,HDL-C水平与疾病活动度呈负相关。结论HDL-C水平对于RA疾病具有保护作用。     

A comparison of plasma cholesterol,triglycerides. and high density lipoprotein-cholesterol in speed skaters,weightlifters and non-athletes

Summary Venous plasma cholesterol, triglycerides and high-density lipoprotein cholesterol (HDL-C) were measured after a 12–16 h overnight fast in three groups of men with different physical training histories. The groups consisted of 11 untrained men (aged 19–25 years), 11 well-trained weightlifters (20–32 years), who had not trained aerobically for at least 6 months, and 11 candidates for an Olympic speed skating team (17–27 years), whose training was both endurance (aerobic) and anaerobic. Mean maximal oxygen uptakes for the groups were 47.7, 45.7, and 62.3 ml·kg^–1·min^–1 respectively. Groups were similar with respect to diet, smoking and alcohol consumption, but the nonathletes were fatter, the weightlifters older and the speed skaters lighter, than the others. There were no significant differences in total cholesterol or triglycerides between the groups. Mean HDL-C was similar in the non-athletes and weightlifters [about 47±7 (SD) mg·dl^–1], but was significantly higher (53.7±10.2 mg·dl^–1, p<0.05) in the speed skaters. It was not correlated significantly with maximal oxygen uptake or relative fat in any group or when all data were combined. The total cholesterol/HDL-C ratio was significantly higher in the weightlifters. The HDL-C values are compared with previously reported values for non-athletes and athletes, and it is concluded that extensive weight-training, in contrast to endurance training, does not increase venous plasma HDL-C. Further work is required to elucidate the biochemical basis of these observations.     

The effect of oestrogen implants on high density lipoproteins and its subfractions in women in their pre-mature menopause

Oestrogen is recognized as having profound effects on lipid and lipoprotein levels. It is also considered as the agent protecting the pre-menopausal woman from arteriosclerotic cardiovascular disease. High density lipoprotein (HDL) has also been ascribed a protective role against the development of arteriosclerosis. The effect of natural oestrogen (17β-oestradiol) administered in the form of a subcutaneous pellet on concentrations of lipids and lipoproteins, particularly high density lipoproteins and its subfractions were determined in three young women with premature menopause. Plasma cholesterol, low density lipoprotein and very low density lipoprotein and very low density lipoprotein levels decreased following oestrogen implantation. High density lipoproteins and in particular subfraction 2 (density cut 1.063-1.125 gm/ml) and subfraction 3 (density cut 1.125-1.21 gm/ml) increased profoundly but there was a slight fall in the HDL 2/HDL 3 cholesterol ratio. The HDL/LDL cholesterol ratio increased from 0.21 to 0.46. A decrease in the urinary FSH levels paralleled these changes in the lipoprotein concentrations. Oestrogen administered in this form, unlike other oestrogen or mixed oestrogen-progestogen compounds is a definite modifier of arteriosclerotic risk, and as such could be given therapeutically in menopausal hypercholesterolemic females.     

Effect of natural early menopause on bone mineral density

OBJECTIVES: Early menopause (EM) is included among the risk factors for osteoporosis. Several studies have shown that women with early menopause have lower bone mineral density (BMD) than those with normal expected age of menopause. The aim of our cross-sectional study was to investigate the effects of time of menopause on vertebral bone mass in healthy postmenopausal women and to evaluate if early menopause is a risk factor for lower vertebral BMD. METHOD: We studied 782 who had never received drugs acting on bone mass. The study population was divided into three groups: women with early, normal (NM), and late (LM) menopause. Our study population was further categorized in 5-year age segments between 45 and >75. RESULTS: The three groups examined did not differ for age, age at menarche, body mass index (BMI), and vertebral BMD, while there were significant differences in age at menopause and years since menopause. Our study showed that women with EM presented significantly lower vertebral BMD than NM and LM in 50-54 age segments. Beyond 55 years, EM, NM, and LM women had no differences in lumbar BMD values. CONCLUSIONS: In conclusion, controversial data demonstrated that the absolute amount of bone loss is greater after early menopause than after normal or late menopause, even if a slight effect of early menopause on bone mass cannot be excluded.     

Effect of PEG spacer on cellulose adsorbent for the removal of low density lipoprotein-cholesterol

Carboxyl modified PEG spacer was synthesized and linked covalently to cellulose beads. L-lysine ligand was coupled to the spacer and its selective affinity for low-density lipoprotein-cholesterol (LDL-C) was determined. It was found that the adsorption capacity and the efficiency of the ligand for adsorption of LDL-C was increased when PEG spacer was used. Experimental results showed that with the chain length of PEG spacers increased from 1000Da to 6000 Da, the average adsorption capacity of LDL-C was enhanced from 0.242 mg/ml to 0.903 mg/ml. Above results indicate that PEG spacers are conducible to the selective removal of LDL-C from human plasma. In addition, LDL-C adsorbent with PEG spacers has a low adsorption capacity for high-density lipoprotein (HDL-C).     

Bone density patterns after normal and premature menopause

Objectives: The investigation of the effect of time and type of menopause on bone mineral density (BMD) at different ages. Methods: Five hundred and fourteen women, who had never received any hormonal substitution were studied in a cross-sectional design: 177 with normal (NMP), 210 with surgical (SUMP) and 127 with premature natural (EMP) menopause. Age at menopause was 49.1±3.9, 38.3±4.7 and 38.1±4.2 years (mean±1 S.D.), respectively. BMD was measured at L2–L4 vertebrae and proximal femur by the DEXA method. Results: EMP women presented significantly lower vertebral BMD than NMP women in the 45–55-years segments (P<0.001), but did not differ from SUMP women. This group exhibited lower vertebral BMD than NMP between 45 and 50 years (P<0.001). Regarding femoral neck, EMP women exhibited lower values than SUMP in the 45–50 and 55–65 age segments (P<0.001) whereas SUMP women presented significantly higher BMD values than NMP women after 55 years of age (P<0.001). The percentages of women with vertebral BMD (T-score values) in the osteoporotic range were significantly greater in EMP compared with either NMP or SUMP groups (both P<0.001) whereas in femoral neck lower in SUMP than the other two categories. Conclusions: Women with either natural or surgical premature menopause exhibit lower BMD of trabecular bone compared with normal menopause women at the age segments 45–55 and 45–50, respectively. However, surgical menopause women exceed normal menopause women in their mixed bone BMD values after 60 years as well as premature natural menopause women at almost all age segments.     

Effects of menopause and hormone replacement therapy on plasma lipids, lipoproteins and LDL-receptor activity

A cross-sectional study of ninety six women was conducted to examine the effect of menopause and hormone replacement therapy (HRT) on plasma lipids, lipoproteins and oxidation of low density lipoproteins. The sample consisted of 26 premenopausal women, 26 postmenopausal women taking no replacement hormones and 43 postmenopausal women on hormone replacement therapy. Postmenopausal women not taking replacement hormones had significantly higher plasma cholesterol, low density lipoprotein (LDL) cholesterol and lipoprotein[a] (Lp[a]) levels compared to premenopausal women or postmenopausal women on HRT [6.00±0.15, 5.36±0.17 (P<0.01), 5.63±0.13 (P<0.05) mmol/l, respectively for total cholesterol; 4.13±0.15, 3.64±0.15 (P<0.05), 3.82±0.12 (P<0.05) mmol/l, respectively for LDL-cholesterol; 48.19±9.90, 26.59±5.53 (P<0.03), 25.12±4.62 (P<0.03) mg/dl, respectively for Lp[a]]. The differences in LDL cholesterol concentrations were inversely related to changes in LDL receptor activity (r=−0.27, P<0.01). HRT use was found to be associated with a significantly smaller LDL particle size. Plasma triglyceride was significantly higher in women on HRT (1.16±0.07 mmol/l) than in the premenopausal group (0.96±0.07) or postmenopausal group not using HRT (0.87±0.06). There were no differences in LDL oxidation between the groups when LDL was oxidised in the presence of copper. Nor was there any difference in the uptake of copper-oxidised or macrophage-modified LDL into J774 macrophages. These results confirm the effect of menopause and exogenous hormones on plasma lipids and lipoproteins, and suggest that HRT modifies the activity of the LDL receptor. Hormone replacement did not appear to protect LDL from oxidation.     

Influence of spontaneous and surgical menopause on atherogenic metabolic risk

We evaluated serum total-, LDL-, HDL-, cholesterol and triglycerides in 858 women. Sixty-seven were in premenopause, 307 in perimenopause, 326 in spontaneous menopause, and 158 women underwent hysterectomy. Of these, 101 had bilateral ovariectomy, 24 with unilateral ovariectomy and 33 with retention of both ovaries. After correcting for chronological age and body mass index by variance analysis, it was found that total-, LDL- and HDL-cholesterol significantly increased during menopause without changes in the total cholesterol/HDL-cholesterol, LDL-cholesterol/HDL-cholesterol and triglycerides/HDL-cholesterol ratio. The changes gradually occurred during the months preceding spontaneous cessation of menses. Atherogenic metabolic risk (as relative risk of high total and LDL-cholesterol, estimated by logistic regression analysis) significantly increased in all groups of women in reference to premenopause. The risk observed in surgical menopause with bilateral ovariectomy was higher than in spontaneous menopause, and conservation of ovaries in hysterectomized women seems to protect only partially against such an increase.     

Influence of marketed herbal menopause preparations on MCF-7 cell proliferation

OBJECTIVE: Given the increasing use of alternative menopause treatments, we evaluated the effect of several herbal preparations used for menopause relief on the proliferation of estrogen-sensitive breast cancer cells (MCF-7) as a means of assessing appropriateness for use in women at risk for estrogen-sensitive breast cancer. DESIGN: An MCF-7 cell culture model, as described previously, was used to evaluate the estrogen-agonist and -antagonist activity of commercially available herbal menopause preparations containing red clover, soy, black cohosh, or a combination of herbs. Each test substance was evaluated for cytotoxic effects before conducting the proliferation assays. RESULTS: Commercially available products containing soy, red clover, and herbal combinations induced an increase in the MCF-7 proliferation rates, indicating an estrogen-agonistic activity in the absence of estradiol. In contrast, an isopropanolic black cohosh extract (Remifemin Menopause) did not stimulate MCF-7 growth and exerted inhibitory effects on cellular proliferation. None of the tested products enhanced estradiol-induced cell proliferation. The black cohosh preparation and one of the herbal combinations exhibited strong estrogen-antagonistic effects. CONCLUSIONS: The lack of proliferative effects of isopropanolic black cohosh extract on estrogen-sensitive breast cancer cells in vitro suggests a favorable safety profile for use in women with a history of breast cancer. Alternatively, preparations containing red clover, soy, and combinations of various herbal ingredients may induce cell proliferation, suggesting that such herbal preparations should be used with caution in the treatment of menopause symptoms in women at risk for, or with a history of, estrogen-sensitive breast cancer.     

Protein-bound lipids in human low density lipoproteins

In vitro oxidation of low density lipoproteins is found to be accompanied by accumulation of sterol and phospholipid residues covalently bound with apolipoprotein B. The content of protein-bound lipids in the subfraction of desialylated low density lipoproteins from healthy subjects and patients with coronary atherosclerosis is shown to be higher than that in native lipoproteins. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, No. 8, pp. 155–157, August, 1995 Presented by E. I. Chazov, Member of the Russian Academy of Medical Sciences     

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.     

Duration of menopause and behavior of malondialdehyde, lipids, lipoproteins and carotid wall artery intima-media thickness.

AIM: our study assessed whether minor or major hormonal deficiency influenced oxidative status and vascular wall structure in menopausal women. METHODS: the study series was made up of 62 non hypertensive non diabetic menopausal women (mean age 52.3+/-4.7 years) divided into two groups depending on duration of menopause (group 1 duration 0-5 years; group 2 duration over 5 years). Total cholesterol (TC), LDL cholesterol (LDL-C), HDL-cholesterol (HDL-C), triglycerides (TG), malondialdehyde (MDA) and common carotid artery wall intima-media thickness (IMT) were determined in the entire series. RESULTS: mean TC, LDL-C, TG, MDA and IMT values were higher in group 2 than group 1. The intergroup difference between MDA (P<0.007) and IMT values (P<0.006) values was statistically significant. CONCLUSIONS: the study revealed a close temporal correlation between plasma oxidative stress and carotid wall IMT, jeopardizes vascular wall status as menopause proceeds.     

Changes in sex hormone binding globulin,high density lipoprotein cholesterol and plasma lipids in male cyclists during training and competition

Summary This study was performed on 13 professional race-cyclists to examine changes in sex hormone binding globulin (SHBG), high density lipoprotein cholesterol (HDL-C) and serum lipid concentrations after training and after competition. While SHBG, total cholesterol and phospholipids increased and free fatty acids (FFA) decreased significantly during training, HDL-C and FFA increased and SHBG and triglycerides (TG) decreased significantly during the competition period. These latter changes in serum lipids and lipoproteins were assumed to be a direct effect of utilisation of muscle and plasma TG as fuels for exertion occurring only in extreme exercise. Changes in SHBG concentrations indicated that they were dependent on the conditions of the physical effort and could be related not only to the concentrations of androgens but also to the reduction in body mass.