Is there a menopausal metabolic syndrome?

Insulin resistance in postmenopausal women with metabolic syndrome and the measurements of adiponectin, leptin, resistin, and ghrelin

OBJECTIVE

Metabolic syndrome (MBS) is a significant health care problem in postmenopausal women and is driven largely by obesity. We wished to assess the prevalence of insulin resistance (IR), diagnosed using practical methods, and whether several adipocyte factors (adiponectin, leptin, resistin) or the gastric peptide ghrelin, associated with cardiovascular risk, might be abnormal and may relate to IR.

STUDY DESIGN

We evaluated 37 obese postmenopausal women with MBS and 34 matched obese premenopausal controls, as well as 14 non-obese premenopausal controls. We measured fasting glucose and insulin, performed 75 g 2 hr oral glucose tolerance and intravenous insulin tolerance tests to assess IR, and measured fasting lipids, adiponectin, leptin, resistin and ghrelin.

RESULTS

The kinetic decline in glucose after insulin (kITT) as a marker of IR was the most frequently abnormal test (abnormal in 81%), with QUICKI, HOMA, and a modification of the Matsuda-DeFronzo index (ISIM) abnormal in 76, 73, and 68%, respectively. The GIR was abnormal in only 35% of subjects. Leptin and resistin were elevated and adiponectin and ghrelin were decreased in the postmenopausal women, compared to both groups of premenopausal controls. BMI correlated strongly with markers of insulin resistance as well as adipocytokine values. After controlling for BMI, only leptin was predictive of ISIM.

CONCLUSION

Being overweight after menopause results in worsening IR and elevations in adipocytokine levels. While BMI is the most important factor, abnormal adipocytokine secretion may enhance IR and increase cardiovascular risk in postmenopausal women.

Assessing the economic impact of chronic conditions in postmenopausal women

The ageing of the US population and the recognised importance of preventative care has led to a growing body of research regarding the morbidity and mortality associated with chronic diseases in postmenopausal women. According to the National Institute of Health, postmenopausal women have a significant increase in risk for a number of debilitating diseases, including osteoporosis, breast cancer and cardiovascular disease. In addition, recently published studies prompted patients, clinicians and payers to re-examine the risks and benefits of a well-accepted therapy to treat postmenopausal symptoms. The objective of this paper is to provide a framework for assessing the economic impact of disorders affecting postmenopausal women, with a particular focus on osteoporosis, breast cancer and cardiovascular disease. This framework considers the prevalence of these conditions, the profiles of women suffering from each of them and prevailing patterns of treatment for these disorders. Taken together, these factors are used to analyse the overall economic impact of postmenopausal disorders and to provide an expert opinion in this context.

The effect of estradiol valerate and dienogest combination on serum homocysteine levels in postmenopausal women: a clinical trial

Several studies have verified that hormone replacement therapy (HRT) has protective effects on postmenopausal women's cardiovascular condition. However, highly significant recent studies have reported that women treated with HRT have more cardiovascular events than untreated women. An elevated homocysteine level is one important risk factor for cardiovascular disease (CVD). As a good indicator of CVD risk, we examined the changes in plasma homocysteine levels of postmenopausal women treated with HRT. In our study, we administered estradiol valerate (2 mg) and dionegest (2 mg) to 34 postmenopausal women recruited randomly from our menopause clinic, and measured plasma homocysteine levels of patients at baseline and after 3 and 6 months of therapy. The changes in plasma homocysteine levels of treated patients were not statistically significant (p = 0.241). Our results indicate that 6 months of estradiol valerate and dionegest therapy does not change homocysteine levels in postmenopausal women.

Effect of 17beta-estradiol on insulin secretion and cytosolic calcium in Min6 mouse insulinoma cells and human islets of Langerhans

OBJECTIVE

Female gonadal steroids can exert an insulinotropic effect in vivo. The objective of this study was to investigate the effects in vitro of 17-beta-estradiol (17beta-E2) on changes in cytosolic calcium ([Ca]i) and on insulin secretion from the MIN6 mouse insulinoma cell line and human primary islets of Langerhans.

METHODS

Stimulus-induced changes in [Ca]i were measured in Fura-2-loaded cells by single cell microfluorimetry. The effects of 17beta-E2 on insulin secretion were measured in static incubation experiments, and the rate and pattern of secretory responses were studied in multi-channel perifusion experiments.

RESULTS

17Beta-E2 (1-100 nmol/L) enhanced basal (2 mmol/L glucose) insulin secretion but had no effect on secretory responses to 20 mmol/L glucose or to depolarizing stimuli (100 micromol/L tolbutamide, 20 mmol/L KCl). Approximately 60% of MIN6 cells responded to 17beta-E2 (1-100 nmol/L) with a small but sustained increase in [Ca]i, whereas 98% of MIN6 cells responded to tolbutamide (100 micromol/L). Similar effects were observed in experiments using human primary beta cells. In contrast, 17beta-E2 had no detectable effect on the increases in [Ca]i evoked by tolbutamide (100 micromol/L) or glucose (20 mmol/L).

CONCLUSIONS

Our observations are consistent with a rapid effect of 17beta-E2 to depolarize beta cells leading to an influx of extracellular Ca and the initiation of insulin secretion by the consequent elevations in [Ca]i. We suggest that this may offer a mechanism through which circulating estradiol can influence beta-cell responsiveness to other signals.

Hormone replacement therapy, selective estrogen receptor modulators, and tissue-specific compounds: cardiovascular effects and clinical implications

In industrialized countries, coronary heart disease (CHD) is not only the leading cause of death in women but of disability as well. Menopause, regardless of age at onset, is associated with a marked increase in CHD risk. Based on epidemiologic studies demonstrating mainly positive biologic effects of hormone replacement therapy (HRT) on CHD risk factors and outcomes, earlier recommendations decreed that most, if not all, postmenopausal women should be treated with long-term HRT. Recent randomized controlled trials with clinical CHD endpoints have shown that previously held dicta may not be accurate. Selective estrogen receptor modulators (SERMs) such as tamoxifen and raloxifene are alternatives to HRT. SERMs represent a growing class of compounds that act as either estrogen receptor agonists or antagonists in a tissue-selective manner. This pharmacologic profile may offer the opportunity to dissociate favorable cardiovascular effects of estrogen from unfavorable stimulatory effects on the breast and endometrium. The only data available regarding the effects of tamoxifen on cardiovascular events in postmenopausal women are from breast cancer trials. They showed fewer fatal myocardial events in women randomly assigned to tamoxifen compared with women assigned to placebo. Raloxifene is a so-called second-generation SERM. It seems clear that raloxifene increases bone mineral density, has no effect on the endometrium, and holds high promise for the prevention of breast cancer. The effect of raloxifene on cardiovascular disease is uncertain. On the basis of the Multiple Outcomes of Raloxifene Evaluation (MORE) trial, raloxifene may offer some protection to women with cardiovascular disease or to those who are at high risk. Proof that raloxifene reduces the risk of CHD requires a clinical trial with hard clinical endpoints. Such a study is currently underway. Clinical trials have demonstrated that the synthetic 19-nortestosterone derivative tibolone reduces climacteric complaints and prevent osteoporosis without causing menstrual bleeding. Tibolone lowers lipoprotein(a), fibrinogen, and plasminogen activator inhibitor-1 levels and improves glucose tolerance, insulin sensitivity, and endothelial function; however, it also lowers high-density lipoprotein cholesterol by >20%. The long-term impact of tibolone on the risk of CHD is not known and needs to be studied.

Tools for making correct decisions regarding hormone therapy. Part II. organ response and clinical applications

OBJECTIVE

To review existing scientific knowledge of the complicated and variable behavior and response to hormone therapy (HT) of different organs during aging, and to summarize long-term consequences on human health.

DESIGN

A MEDLINE computer search was performed to identify relevant articles.

RESULT(S)

Five body organs were evaluated. [1]. Physiologic aging of the bone has deleterious consequences on women's health and quality of life. Bone fractures could be attributed to the combination of estrogen depletion and osteoporosis, mechanisms of applied forces, and disturbed brain function, partially reversible by timely estrogen administration. [2]. Estrogen seems to have a profound neuroprotective effect. As physiologic aging of the brain is an unhealthy phenomenon, possible intervention is justified. The therapeutic time window seems crucial. [3]. The differentiation between response of a healthy or already damaged organ to sex hormones is the key factor to understanding the possible cardioprotective effects. [4]. Based on doubling time of tumor cells, intracrinology, epidemiological data on breast cancer, and behavior of breast cancer survivors in response to estrogen treatment, estrogen seems to be mainly a promoter and even a protector of breast cancer survivors. [5]. Colon cancer appears to be an estrogen-dependent tumor with a wide therapeutic window, as every report regardless of age and dose demonstrates protective effects.

CONCLUSION(S)

Knowledge of each organ's response to aging and sex hormone substitutions demonstrates that the organs could benefit from properly designed intervention. In the wake of the publication of the Women's Health Initiative study, which shocked the medical community, we suggest that the results be reevaluated according to the aforementioned principles, and that menopausal medicine could play an important role.

An update on the antiestrogenic effect of smoking: a literature review with implications for researchers and practitioners

OBJECTIVE

To draw attention to the implications of smoking in the pathogenesis of osteoporosis and for the effectiveness and safety of hormone therapy. DESIGN Summary of own research and a MEDLINE search of English-language literature on the antiestrogenic effect of smoking in pre- and postmenopausal women published during the past two decades.

RESULTS

Numerous observations suggest that part of the detrimental effect of smoking on bone metabolism is mediated by an adverse influence on sex-steroid metabolism, and in particular by an estrogen-lowering effect. Furthermore, in smokers, serum concentrations of estradiol and estrone during oral, but not parenteral, hormone therapy (HT) reach only half the concentrations of nonsmokers. Thus, cigarette smoking may reduce the favorable effects of HT significantly and may even negate the protective effects. In such cases, the failure of preventive therapy is a failure of dosing rather than of HT per se.

CONCLUSIONS

We urge colleagues to take the antiestrogenic effect of smoking into account when drawing conclusions from population-based trials, as well as when prescribing HT to their patients for the prevention of menopause-related health problems.

Differential eicosapentaenoic acid elevations and altered cardiovascular disease risk factor responses after supplementation with docosahexaenoic acid in postmenopausal women receiving and not receiving hormone replacement therapy

BACKGROUND

Dietary docosahexaenoic acid (DHA) has triacylglycerol-lowering potential and undergoes in vivo retroconversion to eicosapentaenoic acid (EPA) in humans. Hormone replacement therapy (HRT) influences circulating lipid concentrations and fatty acid metabolism. DHA supplementation has not been studied in postmenopausal women.

OBJECTIVE

We studied the effects of supplementation with DHA (free of EPA) on the resulting elevation in EPA and on selected cardiovascular disease risk factors in postmenopausal women.

DESIGN

Women receiving (n = 18) and not receiving (n = 14) HRT completed a randomized, double-blind, placebo-controlled crossover trial with a DHA supplement (2.8 g DHA/d). A washout period of > or =6 wk divided the two 28-d intervention periods. Fasting blood samples were collected for analysis.

RESULTS

In all women, DHA supplementation was associated with significant changes (P < 0.05), including 20% lower serum triacylglycerol concentrations, 8% higher HDL-cholesterol concentrations, a 28% lower overall ratio of serum triacylglycerol to HDL cholesterol, and a 7% decrease in resting heart rate. DHA supplementation resulted in a 45% lower net increase (P = 0.02) in EPA and a 42% lower (P = 0.0028) estimated percentage retroconversion of DHA to EPA [DeltaEPA/(DeltaEPA + DeltaDHA) x 100] in women receiving than in those not receiving HRT.

CONCLUSION

With DHA supplementation, the accumulation of EPA in serum phospholipids is significantly attenuated in postmenopausal women receiving HRT compared with that in women not receiving HRT. DHA supplementation can also favorably influence selected cardiovascular disease risk factors in postmenopausal women.

Oral contraceptive use and risk of diabetes among Chinese women

Oral contraceptive (OC) use has been associated with alterations in carbohydrate metabolism. We examined the effect of OC use on the risk of diabetes among Chinese women. A nested case-control study was conducted among 57,130 women screened for diabetes at enrollment for the Shanghai Women's Health Study, a population-based cohort study of Chinese women aged 40-70 years in Shanghai, China. Included in this study were 259 women newly diagnosed with diabetes and 2072 age-matched controls (8 controls per case), randomly selected from women who tested negative for urine glucose. Multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CI) were used to measure the strength of the association between OC use and diabetes risk. Overall, OC use was not associated with the risk of diabetes. Stratified analysis by menopausal status revealed a dose-response relationship between the duration of OC use and the risk of diabetes among premenopausal women (p for trend = 0.02), with a 3.2-fold elevated risk observed among those who used OC longer than 1 year. Risk of diabetes diminished with increasing time since last OC use (p = 0.02). Use of intrauterine devices was associated with a reduced risk of diabetes in both pre- and postmenopausal women (OR = 0.67, CI: 0.48-0.93). These findings suggest that recent use (within 5 years) and continued use (>1 year) of OCs may increase the risk of diabetes among Chinese women. However, the attributable risk for diabetes among OC users in the general population, if confirmed by further studies, appears to be small.

Walking trials in postmenopausal women: effect of low doses of exercise and exercise fractionization on coronary risk factors

We studied the fractionization of walking training and searched for the minimum dose to affect coronary risk factors in two randomized controlled trials. Altogether 134 (Study I) and 121 (Study II) healthy, sedentary postmenopausal women started the trials, and 130 (Study I) and 116 (Study II) completed them. In Study I the exercise intensity was 65% of the maximal aerobic power (VO2max) and a total of 300 kcal was expended in one (Group W1) or two (Group W2) daily walking bouts. In Study II the exercise was continuous, and the exercise intensity (% of VO2max) and energy expenditure (kcal session(-1)) were 55% and 300 kcal (Group W3), 45% and 300 kcal (Group W4), 55% and 200 kcal (Group W5) and 45% and 200 kcal (Group W6). All the subjects walked 5 days a week. The outcome measures were blood pressure, serum lipoproteins and blood glucose and plasma insulin in fasting state and also during 2-h oral glucose tolerance test in Study I. There was no change in diastolic pressure in the original study groups, but in the combined exercise group (W1+W2) in Study I, the mean diastolic pressure declined by -3.0 mmHg (95% con-fidence interval (CI) -5.5 to -0.4) (P=0.025) in comparison with that of the controls. The mean blood glucose declined by -0.21 mmol L(-1) (CI -0.33 to -0.09) in Group W1 and -0.13 mmol L(-1) (CI -0.25 to -0.01) in Group W2 compared to controls (P=0.03). Also the 2-h glucose concentration decreased in Groups W1 and W2 compared to controls. Systolic blood pressure, serum lipoproteins and insulin levels did not change in Study I or Study II. We conclude that our training program with the greatest exercise dose, exercise intensity 65% of VO2max and weekly expenditure of 1500 kcal had a minimal, positive effect on diastolic pressure and blood glucose, and the effect was similar in one or two daily exercise session groups. This exercise dose is probably close to the minimum to affect coronary risk factors in healthy postmenopausal women. To get a more pronounced and clinically relevant effect, a greater exercise dose is needed.

Fatty acid composition of serum phospholipid of premenopausal women and postmenopausal women receiving and not receiving hormone replacement therapy

OBJECTIVE

To compare the fatty acid composition of serum phospholipid of premenopausal women with that of postmenopausal women receiving and not receiving hormone replacement therapy (HRT).

DESIGN

Women between the ages of 43 and 70 were recruited for two separate case-comparison studies. Participants were grouped as either premenopausal, postmenopausal receiving HRT, or postmenopausal not receiving HRT. All participants were required to complete a 3-day dietary record before providing a 12-h fasting blood sample. Fatty acid composition of phospholipids and lipid concentrations was determined from serum samples.

RESULTS

The postmenopausal women receiving HRT had significantly higher concentrations of palmitic acid (16:0), palmitoleic acid (16:1), and di-homo-gamma-linolenic (20:3n-6) and significantly lower levels of docosapentaenoic acid (22:5n-3) than the other groups in both studies. In addition, the postmenopausal women receiving HRT had lower levels of behenic (22:0), lignoceric (24:0), and nervonic acid (24:1) in comparison with the postmenopausal women not receiving HRT.

CONCLUSION

The results of this study indicate that the fatty acid composition of serum phospholipids in women is influenced by menopausal status and hormone use. These results are of interest because high levels of 20:3n-6 and low levels of docosapentaenoic acid have been associated with increased myocardial infarction plus stroke mortality from cardiovascular disease.

Isoflavone-rich soy protein prevents loss of hip lean mass but does not prevent the shift in regional fat distribution in perimenopausal women

OBJECTIVE

Menopause-induced estrogen deficiency increases the risk of cardiovascular disease, which is related to a shift in regional fat distribution. We tested the hypothesis that estrogen-like isoflavones in soy protein isolate (SPI+) would lessen both regional fat gain and lean loss compared with isoflavone-poor soy (SPI-).

DESIGN

Perimenopausal participants (N = 69) were randomly assigned (double-blind) to 24 weeks of treatment (40 g soy or whey protein per day): SPI+ (n = 24), SPI- (n = 24), or whey control (n = 21); each participant had blood drawn in the fasted (12 hours) state, had physical activity assessed, and kept a 5-day food diary. Dual-energy x-ray absorptiometry was used to examine the effects of SPI+ on regional fat and lean tissue distribution changes in the waist, hip, and thigh regions.

RESULTS

Mean body mass increased (P < 0.01) in each group, but treatment had no effect on gain in overall body mass, fat mass, or lean mass using analysis of variance. In all treatment groups combined, lean mass increased in each region; fat mass increased only in the waist region. Treatment had an effect (P = 0.039) on hip lean mass and a marginal effect (P = 0.077) on thigh fat. Regression analyses revealed that SPI+ diminished the increase in thigh fat (P = 0.018) and heightened the increase in hip lean (P = 0.035) mass. Carbohydrate intake (P = 0.006) and cohort (reflective of season; P = 0.011) contributed to the gain in thigh fat. Total protein intake (P = 0.0012), plasma insulin (P = 0.0034), and physical activity (P = 0.047) contributed to the gain in hip lean mass.

CONCLUSIONS

Gain in hip lean mass was greater (P = 0.014) in SPI+ than other groups, but SPI+ did not reduce the disease-promoting menopausal shift in regional fat mass.

Lipoprotein(a): an emerging cardiovascular risk factor

Lipoprotein(a) is a cholesterol-enriched lipoprotein, consisting of a covalent linkage joining the unique and highly polymorphic apolipoprotein(a) to apolipoprotein B100, the main protein moiety of low-density lipoproteins. Although the concentration of lipoprotein(a) in humans is mostly genetically determined, acquired disorders might influence synthesis and catabolism of the particle. Raised concentration of lipoprotein(a) has been acknowledged as a leading inherited risk factor for both premature and advanced atherosclerosis at different vascular sites. The strong structural homologies with plasminogen and low-density lipoproteins suggest that lipoprotein(a) might represent the ideal bridge between the fields of atherosclerosis and thrombosis in the pathogenesis of vascular occlusive disorders. Unfortunately, the exact mechanisms by which lipoprotein(a) promotes, accelerates, and complicates atherosclerosis are only partially understood. In some clinical settings, such as in patients at exceptionally low risk for cardiovascular disease, the potential regenerative and antineoplastic properties of lipoprotein(a) might paradoxically counterbalance its athero-thrombogenicity, as attested by the compatibility between raised plasma lipoprotein(a) levels and longevity.

Systemic hypertension in postmenopausal women: a clinical approach

Gender-specific differences in the incidence of cardiovascular disease have long been known, and estrogens have been considered to be responsible for this dissimilarity. Recently, the steep increase in cardiovascular risk in the no longer fertile woman has become evident. The postmenopausal metabolic syndrome is very frequent, with obesity, insulin resistance, and hyperinsulinemia, which convey increased sodium reabsorption, stimulation of the sympathetic nervous system, and smooth muscle growth. The clinical corollary of these overall changes is hypertension. Gender differences in components of the renin-angiotensin system have been shown to exist, and may play a central role in blood pressure control. In normotensive populations, plasma renin activity is significantly higher in men than in women, and is higher in postmenopausal versus premenopausal women. Two angiotensin-converting enzyme inhibitors, ramipril and moexipril, have undergone trials aimed specifically at older people with cardiovascular risk and with postmenopausal hypertension, and could be the first therapeutic choice. However, a comprehensive treatment should include nonpharmacologic measures with strong emphasis on weight normalization and regular physical activity, prevention of osteoporosis, as well as decisions on the use of estrogen replacement therapy and treatment of the menopausal metabolic syndrome. Finally, education of both patients and physicians on the nature and prognosis of untreated hypertension is crucial.

Metabolic syndrome in the rat: females are protected against the pro-oxidant effect of a high sucrose diet

Metabolic syndrome is more prevalent in men than in women. In an experimental dietary model of metabolic syndrome, the high-fructose-fed rat, oxidative stress has been observed in males. Given that estradiol has been documented to exert an antioxidant effect, we investigated whether female rats were better protected than males against the adverse effects of a high-sucrose diet, and we studied the influence of hormonal status in female rats. Males and females were first fed a sucrose-based or starch-based diet for 2 weeks. In the males, the plasma triglyceride (TG)-raising effect of sucrose was accompanied by significantly lowered plasma alpha-tocopherol and a significantly lowered alpha-tocopherol/TG ratio (30%), suggesting that vitamin E depletion may predispose lipoproteins to subsequent oxidative stress. In males, after exposure of heart tissue homogenate to iron-induced lipid peroxidation, thiobarbituric reactive substances were significantly higher in the sucrose-fed than in the starch-fed rats. In contrast, in sucrose-fed females, neither a decrease in vitamin E/TG ratio nor an increased susceptibility of heart tissue to peroxidation was observed, despite both a significantly decreased heart superoxide dismutase activity (14%) and a significant 3-fold increase in plasma nitric oxide concentration compared with starch-fed females. The influence of hormonal status in female rats was then assessed using intact, ovariectomized, or estradiol-supplemented ovariectomized female rats fed the sucrose or starch diet for 2 weeks. After exposure of heart tissue to iron-induced lipid peroxidation, higher susceptibility to peroxidation was found only in ovariectomized females fed the sucrose diet compared with the starch group and not in intact females or ovariectomized females supplemented with estradiol. Thus, estrogens, by their effects on antioxidant capacity, might explain the sexual difference in the pro-oxidant effect of sucrose diet resulting in metabolic syndrome in rats.

Hormone therapy and the cardiovascular system

The cardiovascular effects of female sex steroids have many faces and are very complex. To make this situation even more complicated different disease situations, different target organs and different therapeutic regimens may exhibit different effects of estrogens and progestines. Furthermore, the interpretation of population studies may be problematic by itself, in view of so many confounders and biases involved and methodological flaws that sometimes are discovered only post-hoc. It seems, therefore, that in such a complicated situation making definite conclusions and guidelines is almost an impossible task. My suggestion to clinicians is to try and follow the main stream of clinical data, looking at the general picture rather than the small details, and try to individualize therapy in order to maximize the benefits and minimize the adverse reactions and risks. This article discusses the current knowledge on hormone replacement therapy (HRT) and the cardiovascular system. It is not an overview, because my intention was not to pump in as much data as possible. Rather, the article presents current ideas and trends in this field to be used by people who practice menopause medicine for their own clinical decisions.

Effect of postmenopausal oestradiol and dydrogesterone therapy on lipoproteins and insulin sensitivity, secretion and elimination in hysterectomised women

OBJECTIVES

To investigate in depth the metabolic effects of oestradiol-17 beta both alone and in combination with the progestagen dydrogesterone.

METHODS

Fifteen hysterectomised postmenopausal women were studied before treatment and after 24 weeks taking oestradiol-17 beta alone (2 mg per day), then following a further 6 (oestrogen-alone phase) and 12 (oestrogen plus progestagen phase) weeks with inclusion of dydrogesterone (10 mg per day for days 17-28 of each 28 day cycle). Measurements at each visit included fasting serum lipid and lipoprotein concentrations, insulin sensitivity, secretion and elimination by modelling analysis of intravenous glucose tolerance test glucose, insulin and C-peptide concentrations, body fat distribution by dual-energy X-ray absorptiometry (DXA) and arterial function by carotid artery ultrasound.

RESULTS

Significant reductions were seen throughout in total and LDL cholesterol. The net reductions in total and LDL cholesterol by the end of the study were 5.8% (P<0.05) and 18.4% (P<0.001), respectively. HDL and HDL subfraction cholesterol concentrations rose during treatment with oestradiol alone, the rise being primarily in the HDL(2) subfraction (+21.6%, P<0.001). Fasting serum triglycerides rose 30% on oestradiol treatment. These increases were unaffected by the addition of dydrogesterone. Insulin sensitivity, secretion and elimination, body fat distribution and arterial function were not significantly affected at any stage of the therapy.

CONCLUSIONS

The small study sample and high variability in measures of glucose and insulin metabolism may have contributed to the absence of the expected significant improvement in these parameters. Orally administered oestradiol had beneficial effects on total, LDL and HDL cholesterol which were unaffected by the addition of dydrogesterone.

Fatty acid compositions of serum phospholipids of postmenopausal women: a comparison between Greenland Inuit and Canadians before and after supplementation with fish oil

OBJECTIVES

We compared serum phospholipid fatty acid compositions, in particular the status of omega-3 polyunsaturated fatty acid (PUFA), of postmenopausal Greenland Inuit women and postmenopausal Canadian women at baseline and after supplementing the Canadian women with a fish-oil product.

METHODS

Fasting serum samples were collected from 15 Inuit subjects from Greenland and 16 non-Inuit subjects from Canada. In addition, eight Canadian subjects provided fasting serum samples after completing a long-chain omega-3 PUFA intervention (2.4 g of eicosapentaenoic acid [EPA] plus 1.6 g of docosahexaenoic acid [DHA] per day) for 28 d. Fatty acid compositions of serum phospholipids of the samples were determined and compared by one-way analysis of variance.

RESULTS

In comparison with the Greenlanders, baseline Canadian women had 73% and 46% less EPA (20:5omega-3) and DHA (22:6omega-3), respectively, and 32% and 91% more linoleic acid (LA; 18:2omega-6) and arachidonic acid (AA; 20:4omega-6), respectively. The omega-3 supplementation in Canadian women increased DHA and decreased LA levels to approach those in Greenland Inuit and raised EPA levels to surpass (45% higher) those in Greenland women (P < 0.0001). In contrast, AA was only moderately lowered (by 16% overall) such that AA levels remained 62% higher in the supplemented Canadians than in the Greenlanders (P < 0.0001).

CONCLUSIONS

Short-term EPA plus DHA supplementation of postmenopausal North American women can mimic the high EPA and DHA levels and lower LA levels in corresponding Inuit women but not the markedly lower levels of AA. The present findings also support the hypothesis of genetically decreased Delta5-desaturase potential in the Greenland Inuit compared with Canadian postmenopausal women.

Effects of a lipid lowering fibrate and hormone replacement therapy on serum lipids and lipoproteins in overweight postmenopausal women with elevated triglycerides

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in women after menopause. In essence major risk factors for CVD are similar in women as for men inclusive of serum lipid perturbations. The effects of estrogens and hormone replacement therapy on lipid metabolism is widely discussed and warrant further evaluation especially when combined with other lipid lowering drugs.

STUDY DESIGN

Postmenopausal women were studied by an open randomised study during 9 months. Subjects were recruited from outpatient clinics in a rural area of Sweden. Major inclusive criteria comprised body mass index (BMI) >28, serum triglycerides >1.5 mmol/l. Participants were at least 12 months postmenopause with a concomitant serum Follicle Stimulating Hormone (FSH) above 28 IU/l. After inclusion in the study patients were instructed to adhere to a low-fat and caloric diet for 3 months and after this period randomised into two groups of intervention; a lipidlowering fibrate (LLF) group and one hormone replacement therapy group (HRT). The LLF group was given gemfibrozil 600 mg orally twice daily and HRT group received 2 mg oestradiol in combination with 1 mg norethisterone acetate as a continuous combined therapy once daily. After 3 months, the LLF group added the HRT regimen and patients in the HRT group added gemfibrozil. Hence, all participants received the regimens combined for the last 6 months of the study.

RESULTS

Serum s-cholesterol was markedly decreased in both groups during the first 3 months of single treatment (P<0.0001). This decrease reflected a reduction especially of calculated low density lipoprotein (LDL) s-cholesterol (P<0.001). High density lipoprotein (HDL) s-cholesterol was reduced in the HRT group (P<0.005) but increased (P<0.004) in the LLF group. Triglycerides were also decreased by both treatments but more marked in the LLF group (P<0.0001) than in the HRT group (P<0.02). After 9 months the reduction remained in both groups but no additive effects were encountered in any of the groups.

CONCLUSION

The effects by gemfibrozil on s-cholesterol and triglycerides levels seem to be superior to continuous combined HRT in overweight women with elevated triglycerides. The combination of the two drugs did not seem to offer any additional benefit concerning the routine serum lipid or lipoprotein profile.

Supraphysiological concentrations of estradiol in menopausal women given repeated implant therapy do not adversely affect lipid profiles

BACKGROUND

The effects of oral estrogen therapy (ERT) on lipids and metabolic parameters are well known, in contrast to the effects of subcutaneously administered estrogen, particularly high concentrations of estrogen. We examined metabolic parameters in cohorts of women with and without subcutaneous estrogen therapy with concomitant supra-normal concentrations of estradiol (SE).

METHODS

Lipids and lipoprotein concentrations, low density lipid (LDL) subfractions, and activity of hepatic lipase (HL) were assessed in 30 menopausal women with SE and 19 control subjects not using ERT, matched for body mass index and age.

RESULTS

Waist-hip ratio (WHR) and fasting insulin (FI) concentrations were lower in the SE group compared with the women not on ERT (P < 0.05). The concentrations of triglyceride and high density lipid (HDL) cholesterol were similar (P > 0.1), whereas total cholesterol (P < 0.05), LDL cholesterol (P < 0.05), and HL activity (P < 0.01) were lower in the SE group. Concentrations of the large, buoyant LDL I subfraction were significantly lower in the SE group (P < 0.05), but there was no difference in LDL III concentrations.

CONCLUSIONS

Women with SE have similar triglyceride and HDL cholesterol levels but lower LDL cholesterol concentrations compared with post-menopausal women not taking ERT. The observations that the SE group showed reduced fasting insulin and WHR suggest that supra-normal circulating concentrations of estradiol, delivered subcutaneously, may beneficially influence insulin metabolism.

Obesity and sarcopenia after menopause are reversed by sex hormone replacement therapy

OBJECTIVE

Menopause is linked to an increase in fat mass and a decrease in lean mass exceeding age-related changes, possibly related to reduced output of ovarian steroids. In this study we examined the effect of combined postmenopausal hormone replacement therapy (HRT) on the total and regional distribution of fat and lean body mass.

RESEARCH METHODS AND PROCEDURES

Sixteen healthy postmenopausal women (age: 55 +/- 3 years) were studied in a placebo-controlled, crossover study and were randomized to 17beta estradiol plus cyclic norethisterone acetate (HRT) or placebo in two 12-week periods separated by a 3-month washout. Total and regional body composition was measured by DXA at baseline and in the 10th treatment week in both periods. Changes were compared by a paired Student's t test.

RESULTS

The change in body weight during HRT was equal to the change during placebo (-24.6 g vs. -164 g, p = 0.42), but relative fat mass was significantly reduced (-0.5% vs. +1.24%, p < 0.01). During HRT, compared with during placebo, lean body mass increased (+347 g vs. -996 g, p < 0.01) and total fat mass decreased (-400 g vs. +836 g, p = 0.06). Total bone mineral content increased (+28.9 g vs. -4.4 g, p = 0.04) and abdominal fat decreased (-185 g vs. +253 g, p = 0.04) during HRT compared with placebo.

DISCUSSION

HRT is linked to the reversal of both menopause-related obesity and loss of lean mass, without overall change in body weight. The increase in lean body mass during HRT is likely explained by muscle anabolism, which in turn, prevents disease in the elderly.

Hypertension in menopausal women--a special case, for special treatment?

After the menopause the consequences of hypertension in women change. Their risks of myocardial infarction and stroke rise steeply, a rise that has been blamed in part on the loss of estrogen and the onset of menopausal metabolic syndrome, with endothelial dysfunction, hyperlipidemia, insulin resistance and derangement in coagulation. Hypertensive menopausal women have not had optimum treatment. They have poorer prognoses than men of the same age. Their antihypertensive management therefore merits special attention. Hormone replacement, aspirin prophylaxis and lipid-lowering drugs have their place. The antihypertensive drug chosen should not worsen the metabolic syndrome: angiotensin-II converting enzyme (ACE) inhibitors are therefore among the first-line drugs. Few drugs have been specifically aimed at menopausal hypertension and these are reviewed here.

Effects of lower doses of conjugated equine estrogens and medroxyprogesterone acetate on plasma lipids and lipoproteins, coagulation factors, and carbohydrate metabolism

OBJECTIVE

To determine the effects of lower doses of conjugated equine estrogens (CEE) alone or CEE and medroxyprogesterone acetate (MPA) on lipoproteins, carbohydrate metabolism, and coagulation/fibrinolytic factors.

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

Multicenter substudy of the Women's HOPE trial.

PATIENT(S)

Seven hundred and forty-nine healthy, postmenopausal women.

INTERVENTION(S)

Women were randomized to receive the following doses in milligrams per day: 0.625 CEE; 0.625 CEE/2.5 MPA; 0.45 CEE; 0.45 CEE/2.5 MPA; 0.45 CEE/1.5 MPA; 0.3 CEE; 0.3 CEE/1.5 MPA; or placebo.

MAIN OUTCOME MEASURE(S)

Assessment of lipids, lipoproteins, glucose tolerance, and coagulation/fibrinolytic factors at baseline, cycle 6, and year 1.

RESULT(S)

One year of treatment with any of the CEE or CEE/MPA regimens studied increased high-density lipoprotein cholesterol (HDL-C); the 10% increase in HDL-C for the CEE 0.45/MPA 1.5 group was similar to the CEE 0.625/MPA 2.5 group. Low-density lipoprotein cholesterol was significantly reduced in all of the active treatment groups except the CEE 0.3/MPA 1.5 group at cycle 13. Apolipoprotein A-I and triglyceride levels increased and apolipoprotein B levels decreased in all groups. The lipoprotein (a) level was reduced in the CEE 0.45/MPA 2.5, CEE 0.45/MPA 1.5, and CEE 0.625/MPA 2.5 groups. Minimal changes were observed in carbohydrate metabolism for all groups. Fibrinogen and PAI-1 activity decreased and plasminogen activity increased in all groups. Decreases in antithrombin III and protein S activities were significant for all active treatment groups except the CEE 0.3/MPA 1.5 group.

CONCLUSION(S)

Lower doses of CEE and CEE/MPA induce favorable changes in lipids, lipoproteins, and hemostatic factors with minimal changes in carbohydrate metabolism.

The use of hormone replacement therapy in postmenopausal women with type 2 diabetes

In healthy postmenopausal women, estrogen or hormone replacement therapy (ERT or HRT) can alleviate menopausal symptoms and prevent osteoporosis and may also protect against cardiovascular disease (CVD). In addition to improving lipid metabolism, there are reports that estrogen also improves parameters regulating carbohydrate metabolism, including insulin resistance, in healthy women. Therefore, it is likely that ERT or HRT would also benefit women with type 2 diabetes, not only in relieving menopausal symptoms but also in improving the metabolic abnormalities associated with diabetes and in preventing cardiovascular disease.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

Effect of a fish-oil concentrate on serum lipids in postmenopausal women receiving and not receiving hormone replacement therapy in a placebo-controlled, double-blind trial

BACKGROUND

n-3 Fatty acid supplementation lowered serum triacylglycerol concentrations in studies in which most of the subjects were male. The effects of n-3 fatty acid supplementation in postmenopausal women receiving and not receiving hormone replacement therapy (HRT) have received little attention.

OBJECTIVE

We sought to determine the effects of a fish-oil-derived n-3 fatty acid concentrate on serum lipid and lipoprotein risk factors for cardiovascular disease in postmenopausal women receiving and not receiving HRT, with an emphasis on serum triacylglycerol concentrations and the ratio of triacylglycerol to HDL cholesterol.

DESIGN

Postmenopausal women (n = 36) were grouped according to exogenous hormone use and were randomly allocated to receive 8 capsules/d of either placebo oil (control) or n-3 fatty acid-enriched oil (supplement). The supplement provided 2.4 g eicosapentaenoic acid (EPA) plus 1.6 g docosahexaenoic acid (DHA) daily. Serum lipids and the fatty acid composition of serum phospholipids were determined on days 0 and 28.

RESULTS

Supplementation with n-3 fatty acids was associated with 26% lower serum triacylglycerol concentrations (P < 0.0001), a 28% lower overall ratio of serum triacylglycerol to HDL cholesterol (P < 0.01), and markedly greater EPA and DHA concentrations in serum phospholipids (P < 0.05).

CONCLUSIONS

These results show that supplementation with a fish-oil-derived concentrate can favorably influence selected cardiovascular disease risk factors, particularly by achieving marked reductions in serum triacylglycerol concentrations and triacylglycerol:HDL cholesterol in postmenopausal women receiving and not receiving HRT. This approach could potentially reduce the risk of coronary heart disease by 27% in postmenopausal women.

Different association of hypertension and insulin-related metabolic syndrome between men and women in 8437 nondiabetic Chinese

Insulin resistance may cause a metabolic syndrome but whether insulin resistance causes hypertension is very controversial. Furthermore, it remains unclear whether the link between the insulin-resistance-related metabolic syndrome and hypertension is different between men and women. We examined fasting insulin, glucose, triglyceride and high-density lipoprotein (HDL)-cholesterol levels, systolic blood pressure, body mass index, and waist-to-hip ratio in a dataset from 8437 nondiabetic residents (age range, 30 to 89 years) in Kinmen. Factor analysis, a multivariate correlation statistical technique, was used to investigate the clustering and interdependence of these risk variables. Factor analysis identified two factors for men (n = 3659) and three factors for women (n = 4778, respectively. In men, a cluster of insulin, triglyceride, HDL-cholesterol, body mass index, and waist-to-hip ratio (metabolic syndrome) accounted for 29.7%, and a cluster of systolic blood pressure and glucose (hyperglycemia plus hypertension) accounted for 18.1% of the total variance in all variables considered. In women, a cluster of insulin, triglyceride, body mass index, waist-to-hip ratio, and systolic blood pressure (metabolic syndrome plus hypertension) accounted for 29.4%, a cluster of systolic blood pressure, glucose, and triglyceride (hyperglycemia plus hypertension plus dyslipidemia) accounted for 14.0%, and a cluster of triglyceride and HDL-cholesterol (dyslipidemia) accounted for 16.2% of the total variance. In conclusion, a distinct insulin-resistance-related metabolic syndrome characterized by hyperinsulinemia, dyslipidemia, and obesity was observed for both men and women in this Chinese population. However, hypertension was linked to the metabolic syndrome in women only.

A unifying hypothesis of Alzheimer's disease. III. Risk factors

Normal ageing and Alzheimer's disease (AD) have many features in common and, in many respects, both conditions only differ by quantitative criteria. A variety of genetic, medical and environmental factors modulate the ageing-related processes leading the brain into the devastation of AD. In accordance with the concept that AD is a metabolic disease, these risk factors deteriorate the homeostasis of the Ca(2+)-energy-redox triangle and disrupt the cerebral reserve capacity under metabolic stress. The major genetic risk factors (APP and presenilin mutations, Down's syndrome, apolipoprotein E4) are associated with a compromise of the homeostatic triangle. The pathophysiological processes leading to this vulnerability remain elusive at present, while mitochondrial mutations can be plausibly integrated into the metabolic scenario. The metabolic leitmotif is particularly evident with medical risk factors which are associated with an impaired cerebral perfusion, such as cerebrovascular diseases including stroke, cardiovascular diseases, hypo- and hypertension. Traumatic brain injury represents another example due to the persistent metabolic stress following the acute event. Thyroid diseases have detrimental sequela for cerebral metabolism as well. Furthermore, major depression and presumably chronic stress endanger susceptible brain areas mediated by a host of hormonal imbalances, particularly the HPA-axis dysregulation. Sociocultural and lifestyle factors like education, physical activity, diet and smoking may also modulate the individual risk affecting both reserve capacity and vulnerability. The pathophysiological relevance of trace metals, including aluminum and iron, is highly controversial; at any rate, they may adversely affect cellular defences, antioxidant competence in particular. The relative contribution of these factors, however, is as individual as the pattern of the factors. In familial AD, the genetic factors clearly drive the sequence of events. A strong interaction of fat metabolism and apoE polymorphism is suggested by intercultural epidemiological findings. In cultures, less plagued by the 'blessings' of the 'cafeteria diet-sedentary' Western lifestyle, apoE4 appears to be not a risk factor for AD. This intriguing evidence suggests that, analogous to cardiovascular diseases, apoE4 requires a hyperlipidaemic lifestyle to manifest as AD risk factor. Overall, the etiology of AD is a key paradigm for a gene-environment interaction. Copyright 2000 John Wiley & Sons, Ltd.

17 beta-estradiol reduces glycoxidative damage in the artery wall

Glycoxidative damage in the vasculature has been linked to atherosclerotic cardiovascular disease. Estrogens protect against the development and progression of atherosclerosis. Because estrogens are potent antioxidants that also effect glucose metabolism, part of their protection against atherosclerosis could be through attenuation of glycoxidative damage in the vascular wall. In this study, we tested the hypothesis that chronic estradiol administration is associated with decreased levels of glycoxidative damage in arterial walls. We harvested and examined iliac arteries from ovariectomized, 8-month-old rats that had been implanted for 6 months with 1 of the following subcutaneous hormone pellets: low estradiol (2.5 mg estradiol), high estradiol (25 mg estradiol), P4 (200 mg progesterone), low estradiol and P4, placebo (no hormone), or control (no implant). Using pentosidine as a biomarker of glycoxidative damage, we found that all vessels from rats receiving estradiol (low estradiol, high estradiol, and low estradiol+P4) exhibited a 50% reduction in glycoxidative damage compared with P4, placebo, and control vessels (P<0.05). Consistent with this finding, we observed that estradiol-treated rats had a 30% decrease in tissue levels of hydroperoxides, a marker of oxidative stress. Finally, estradiol-treated rats had a small, but significant, decrease in plasma glucose levels (P<0.01). In summary, we report the novel finding that chronic estrogen administration is associated with significant decreases in glycoxidative damage and oxidative stress in the arterial wall. It seems likely that these actions may constitute a mechanism by which estrogen attenuates the progression of atherosclerosis.