Metabolic effects of the menopause and oestrogen replacement

The Epidemiology of Coronary Heart Disease and HRT What are the Contentious Issues?

Coronary heart disease (CHD) in women is an important public health problem although not one that generates much public concern. Most doctors seem to believe that hormone replacement therapy (HRT) can reduce the incidence of heart disease in women after the menopause but the evidence for this is contentious.

Epidemiological studies have consistently shown a cardioprotective effect for HRT. Critics suggest that these studies are flawed because women who take HRT may be healthier than others in ways that have not been assessed in the studies. Large primary prevention trials are under way but such studies are extremely difficult to design and conduct and may yet fail to provide the conclusive results needed to resolve the debate. An important randomised trial of HRT in secondary prevention has recently been published showing no benefit in the short term but a possible long term benefit.

In practice, the potential public health impact of HRT in the prevention of CHD will be limited by current public attitudes to the safety of HRT, and the reluctance of older women to take HRT for prolonged periods. Women with established CHD or diabetes might benefit more from HRT, but are currently less likely to receive it.

Conjugated estrogen/progestagen versus tibolone hormone replacement therapy in postmenopausal women: Effects on carbohydrate metabolism and serum sex hormone-binding globulin

OBJECTIVE

To study the effects of different types of continuous hormone replacement therapy on carbohydrate metabolism.

METHOD

Postmenopausal women were treated with conjugated estrogens, 0.625 mg/medroxyprogesterone acetate, 2.5 or 5 mg (CEE/MPA) or tibolone 2.5 mg daily for 13 28-day cycles. Serum glucose and insulin were measured before and during a 75 g oral glucose tolerance test (OGTT) at baseline and after 3, 6 and 13 cycles and areas under the curve (AUC) were calculated. Sex hormone-binding globulin (SHBG) was measured as an additional marker of nutritional and insulin status.

RESULTS

Neither CEE/MPA 2.5mg nor tibolone had any effects on carbohydrate metabolism while AUC(insulin), AUC(glucose) and also body mass index (BMI) increased after 13 cycles of treatment in the CEE/MPA 5 mg group. SHBG increased significantly during CEE/MPA treatment and decreased significantly during treatment with tibolone. The effects on SHBG were less pronounced in the CEE/MPA 5mg group. Pretreatment SHBG showed significant negative correlations to BMI and to variables that may reflect a certain degree of insulin resistance, the most pronounced being fasting glucose. Changes in SHBG during treatment with tibolone were negatively correlated to pretreatment SHBG and positively to BMI, AUC(insulin) and fasting insulin resistance index, while no such correlations were found in the CEE/MPA groups. There were no correlations between changes in AUC(insulin) and AUC(glucose) on one hand and basal variables or treatment SHBG on the other in the CEE/MPA groups.

CONCLUSION

The effects of tibolone and CEE/MPA on carbohydrate metabolism were considered to have clinical significance only for CEE/MPA 5mg, indicating a less favourable role of the higher progestagen dose. The results further support the important role of metabolic and insulin status in the physiological regulation of SHBG and also indicate that the suppressive effect of tibolone on circulating SHBG is mainly depends on pretreatment SHBG levels. SHBG does not reflect changes in carbohydrate metabolism during CEE/MPA treatment.

Plasma lipids and urinary albumin excretion rate in Type 1 diabetes mellitus: the EURODIAB IDDM Complications Study

AIMS

To examine the relationship between increased urinary albumin excretion rate and fasting plasma lipids among male and female respondents to the EURODIAB IDDM Complications Study, and attempt to explain inconsistencies in previous reports.

METHODS

A cross-sectional study of 3250 randomly selected Type 1 diabetic patients from 31 diabetes clinics in 16 European countries was carried out between 1989 and 1990. Plasma lipids and urinary albumin were measured centrally. The present analysis was confined to the subgroup of 2205 patients attending after a 10-12 h overnight fast. Mean age was 33 years (SD 10) and mean duration of Type 1 diabetes mellitus was 15 years (SD 9).

RESULTS

The prevalence of microalbuminuria (24-h urinary albumin excretion rate 20-200 microg/min) was 21.7% (95% confidence interval 19.9-23.5) and macroalbuminuria (24-h urinary albumin excretion rate > 200 microg/min) 7.8% (6.6-9.0). In comparison to patients with normal urinary albumin excretion rate (< 20 microg/min), and after controlling for age, sex, glycaemic control, duration of diabetes and current smoking, macroalbuminuria was associated with significantly (P<0.01) increased fasting plasma triglycerides, cholesterol, LDL-cholesterol, cholesterol:HDL-cholesterol ratio and, in women, reduced HDL-cholesterol. In men and women with microalbuminuria, the only significant association was with increased plasma triglycerides.

CONCLUSIONS

These data confirm that there is an association between fasting plasma lipids and increasing urinary albumin excretion rate in European Type 1 diabetic patients. In microalbuminuric patients, however, the association was weaker than previously reported and partly explained by confounding factors.

Oestrogen and progestogen hormone replacement therapy for peri-menopausal and post-menopausal women: weight and body fat distribution

BACKGROUND

Hormone replacement therapy (HRT) is commonly prescribed to treat menopausal symptoms and to prevent post-menopausal bone loss. However, many women are concerned about hormonal replacement therapy because they believe that such treatment will result in weight gain. The effect of HRT on weight and body fat distribution has not yet been examined in systematic reviews. It is an important topic since many women decline oestrogen therapy due to their concerns about resultant weight gain, and thus forego its potential therapeutic benefits.

OBJECTIVES

To evaluate the effect of unopposed oestrogen or combined oestrogen and progestogen hormone replacement therapy (HRT) upon the weight and body fat distribution of perimenopausal and postmenopausal women.

SEARCH STRATEGY

The search strategy of the Menstrual Disorders and Subfertility Group was used for the identification of randomised controlled trials (RCTs). Computerised searches of MEDLINE, EMBASE, Current Contents, Biological Abstracts and CINAHL were performed. Attempts were made to identify trials from citation lists of review articles and relevant papers already obtained. In most cases, first authors of each eligible trial were contacted for additional information. All those trials that had been located as at August 1998 were examined for eligibility.

SELECTION CRITERIA

All randomised, placebo or no treatment controlled trials that detailed the effect of HRT on weight or body fat distribution, including studies where HRT was combined with other therapy such as diet, supplements or exercise. Studies were eligible for consideration even though the main focus of the trial may have been on another aspect of HRT. Previous HRT use should have ceased at least one month (in the case of patches, cream or gel) or three months (for oral preparations or subcutaneous pellets) before commencement of the study.

DATA COLLECTION AND ANALYSIS

Twenty two RCTs were identified that fulfilled the inclusion criteria for this review. The results of one trial were not available in a form that allowed it to be included in the meta-analysis; however, it has been included in the text of the review for discussion. Twenty four RCTs are awaiting assessment pending additional information from first authors. Two reviewers extracted the data independently, and the weighted mean differences for continuous outcomes were estimated from the data. Results for unopposed oestrogen and combined oestrogen were analysed separately, and the effect of each treatment regimen on body weight, BMI, waist-hip ratio, fat mass and skinfold measurement was examined where available. The effect of differing dosage levels on these parameters was also examined.

MAIN RESULTS

Outcomes were evaluated separately for unopposed oestrogen and oestrogen/progestogen regimens. Statistical analysis was performed using the weighted mean difference for continuous outcomes as recommended by the Cochrane Menstrual Disorders and Subfertility Group. No statistically significant difference was found in mean weight gain between those using unopposed oestrogen and non-HRT users (0.66 kg, 95% CI -0.62, 1.93). No significant difference was found in mean weight gain between those using oestrogen/progestogen therapy and non-HRT users (-0.47 kg, 95% CI -1.63, 0.69). Insufficient data exist to enable meta-analysis of the effect of unopposed oestrogen on BMI. The reviewers found no statistically significant difference in mean BMI increase between those using oestrogen/progestogen and non-HRT users (-0.50, 95% CI -1.06, 0.06). Insufficient data exist to enable meta-analysis of the effect of HRT on waist-hip ratio, fat mass or skinfold thickness.

REVIEWER'S CONCLUSIONS

There is evidence of no effect of unopposed oestrogen or combined oestrogen on body weight, indicating that these regimens do not cause extra weight gain in addition to that normally gained at menopause. (ABSTRACT TRUNCATED)

Evaluation and management of amenorrhea

All women who enter menopause experience amenorrhea unless they receive hormone replacement therapy. In younger women, amenorrhea unrelated to pregnancy and lactation can be a distressing symptom. In addition to its psychologic morbidity, amenorrhea may be the manifesting feature of a wide array of anatomic and endocrine abnormalities. Amenorrhea results in impaired fertility. When estrogen levels are low, changes in mineral, glucose, and fat metabolism accompany amenorrhea. These metabolic changes affect bone and cardiovascular health, increasing the risk of osteoporosis and coronary heart disease in later life. Amenorrhea with hyperandrogenism, most commonly caused by the polycystic ovarian syndrome, may cause endometrial hyperplasia and increases the risk of endometrial adenocarcinoma. Because of the broad differential diagnosis of amenorrhea, establishing an accurate diagnosis can prove challenging. In this article, we outline one approach to the assessment of patients with amenorrhea and to the management of its common causes and consequences.