The impact of estrogen replacement therapy and raloxifene on osteoporosis, cardiovascular disease, and gynecologic cancers

Lipid Profile in Patients With Primary Ovarian Insufficiency: A Systematic Review and Meta-Analysis

Backgrounds

A large number of studies have investigated the effect of early menopause on cardiovascular disease (CVD) outcomes and the relationship between the levels of lipid profile and primary ovarian insufficiency (POI). However, the results are inconsistent. The aim of this meta-analysis was to assess whether the levels of total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL) changed in women with POI relative to healthy controls.

Methods

To identify eligible studies, references published prior to December 2021 were searched in the PubMed, Embase, Cochrane Library and Web of Science databases. DerSimonian-Laird random-effects model was used to estimate the overall standard mean difference (SMD) between POI and healthy control subjects. Subgroup analysis and sensitivity analysis were preformed, and publication bias was assessed.

Results

A total of 12 studies featuring 846 women with primary ovarian insufficiency and 959 healthy women were selected for analysis. The meta-analysis showed that the levels of TC (SMD: 0.60; 95% CI: 0.32 to 0.89; P<0.0001), TG (SMD: 0.36; 95% CI: 0.12 to 0.60; P=0.003), LDL (SMD: 0.46; 95% CI: 0.16 to 0.76; P=0.003) were significantly increased in women with POI. There was no significant change in the level of HDL (SMD: 0.25; 95% CI: -0.12 to 0.61; P=0.19). Subgroup analysis showed that the heterogeneity in this meta-analysis of the correlation between lipid profile and POI might come from by region, sample size, number of cases, mean body mass index (BMI) value of cases and mean age of cases.

Conclusions

Scientific evidence suggests that the lipid profile levels were altered in patients with primary ovarian insufficiency compared to healthy controls. Therefore, we recommend that early medical intervention (e.g., hormone replacement therapy) to minimize the risk of CVD morbidity and mortality associated with dyslipidemia in patients with POI.

Systematic Review Registration

PROSPERO, identifier CRD42021297088.

Combined Effects of Phytoestrogen Genistein and Silicon on Ovariectomy-Induced Bone Loss in Rat

This study was performed to evaluate the effect of concomitant supplementation of genistein and silicon on bone mineral density and bone metabolism-related markers in ovariectomized rat. Three-month-old Sprague Dawley female rats were subjected to bilateral ovariectomy (OVX) or sham surgery, and then the OVX rats were randomly divided into four groups: OVX-GEN, OVX-Si, OVX-GEN-Si, and OVX. Genistein and silicon supplementation was started immediately after OVX and continued for 10 weeks. In the OVX-GEN group, 5 mg genistein per gram body weight was injected subcutaneously. The OVX-Si group was given soluble silicon daily in demineralized water (Si 20 mg/kg body weight/day). The OVX-GEN-Si group was given subcutaneous injections of 5 mg genistein per gram body weight, at the same time, given soluble silicon daily (Si 20 mg/kg body weight/day). The results showed that the genistein supplementation in the OVX rats significantly prevented the loss of uterus weight; however, the silicon supplementation showed no effect on the uterus weight loss. The lumbar spine and femur bone mineral density was significantly decreased after OVX surgery; however, this decrease was inhibited by the genistein and/or silicon, and the BMD of the lumbar spine and femur was the highest in the OVX-GEN-Si-treated group. Histomorphometric analyses showed that the supplementation of genistein and/or silicon restored bone volume and trabecular thickness of femoral trabecular bone in the OVX group. Besides, the treatment with genistein and silicon for 10 weeks increased the serum levels of calcium and phosphorus in the OVX rats; serum calcium and serum phosphorus in the OVX-GEN-Si group were higher than those in the OVX-GEN and OVX-Si group (P < 0.05). At the same time, the treatment with genistein and/or silicon decreased serum alkaline phosphatase (ALP) and osteocalcin, which were increased by ovariectomy; serum ALP and osteocalcin in the OVX-GEN-Si group were lower than those in the OVX-GEN and OVX-Si groups (P < 0.05). The results above indicate that genistein and silicon have synergistic effects on bone formation in ovariectomized rats.

Beneficial effects of raloxifene and atorvastatin on serum lipids and HDL phospholipids levels of postmenopausal women

Selective oestrogen receptor modulators (raloxifene) and statins (atorvastatin) have been shown to reduce the risk of cardiovascular disease associated with the postmenopausal status. Their beneficial effects may be mediated partly by favourable changes in serum lipids and particular on HDL phospholipid composition. In the present study, individual administration of either raloxifene (Group A) or atorvastatin (Group B) or both (Group C) was compared for a period of 3 months and their effects on total lipids and HDL phospholipids were evaluated. The combined treatment of raloxifene and atorvastatin resulted in profound changes in the majority of serum lipids, including a significant reduction in total cholesterol and triglycerides (P<0.001), a rise in total phospholipids (P<0.01) and a reduction in LDL-C and Apo B levels (P<0.001). Furthermore, Apo A-I was elevated (P<0.001) whereas total HDL phospholipids were significantly increased (P<0.05). Specifically, HDL phosphatidylcholine levels were markedly increased (P<0.001) and HDL lysophosphatidylcholine, sphingomyelin and phosphatidylinositol levels were reduced (P<0.05). A further attempt to evaluate each treatment group was performed and the significance of these results is discussed.

Evidence of improved serum fatty acid profile of postmenopausal women receiving atorvastatin and raloxifene

Raloxifene and atorvastatin have been shown to reduce the risk of cardiovascular disease associated with postmenopausal status and it has been postulated that their effects may be partly mediated by favourable changes in serum lipids and fatty acid composition. In the present study, individual administration of either raloxifene (Group A) or atorvastatin (Group B) or both (Group C) was compared for a period of 3 months and their effects on total lipids and fatty acids composition was evaluated. Postmenopausal women receiving both raloxifene and atorvastatin showed significant changes in the majority of serum lipids with important reductions in total cholesterol (p < 0.001), triglycerides (p < 0.001), LDL-C (p < 0.001) and Apo B levels (p < 0.001). Phospholipids concentrations (p < 0.01) as well as Apo A-I were also significantly raised (p < 0.001). Furthermore, oleic acid (18:1) and linoleic acid (18:2) levels were significantly increased (p < 0.01 and p < 0.001 respectively) followed by a marked reduction in palmitic acid (16:0) and arachidonic acid (20:4) concentrations (p < 0.01 and p < 0.001 respectively). The results of the study indicate that the serum lipid and fatty acid composition in postmenopausal women is influenced by the combined treatment of raloxifene and atorvastatin and a further attempt to evaluate the significance of these results is discussed.

Duration of tamoxifen effect on lipidemic profile of postmenopausal breast cancer patients following deprivation of treatment

OBJECTIVE

It was the aim of this study to investigate the effect of tamoxifen withdrawal on markers of lipid metabolism in postmenopausal women with breast cancer who completed tamoxifen therapy and received no further treatment.

METHODS

Lipidemic profile changes were studied in 190 postmenopausal patients with operable breast cancer, following cessation of 5-7 years of tamoxifen treatment. Assessments of total cholesterol, high-density lipoprotein, low-density lipoprotein and total serum triglycerides were performed at baseline, 6 months and 12 months.

RESULTS

By 6 months, both total cholesterol and low-density lipoprotein levels were significantly increased, and total triglyceride levels were significantly reduced compared with baseline values and maintained to 12 months. There was no significant alteration observed for high-density lipoprotein levels over the study period.

CONCLUSION

The beneficial effect of tamoxifen on the lipidemic profile of postmenopausal breast cancer patients seems to be lost in less than 12 months time following cessation of 5-7 years of tamoxifen treatment. A 'rebound effect' on the lipidemic parameters should be expected and those patients should be monitored carefully.

Hormone replacement therapy and breast carcinoma risk in Hispanic and non-Hispanic women

BACKGROUND

Hormone replacement therapy (HRT) alleviates menopausal symptoms and prevents osteoporosis, but there is concern that long-term use may have an adverse impact on breast carcinoma risk. Epidemiologic studies report inconsistent findings regarding the relationship between HRT and postmenopausal breast carcinoma risk and there is little information on the HRT-associated risk among minority women.

METHODS

To investigate the effects of HRT on breast carcinoma risk among Hispanic women, we examined data from the New Mexico Women's Health Study (NMWHS), a statewide case-control study comprising 366 postmenopausal women with breast carcinoma and 403 controls. Conditional logistic regression was used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

After adjustment for sociodemographic, medical, and reproductive factors, we found an increased risk associated with long-term users of estrogen replacement therapy (ERT; OR for ERT use longer than 140 months was 2.57, 95%CI, 1.25-5.28, compared with ERT use shorter than 17 months). In addition, there was a positive trend with the duration of ERT use (P < 0.01). Hispanic postmenopausal women appeared to be at a significantly greater risk than non-Hispanic white women (OR for ERT use longer than 140 months in Hispanics was 5.53, 95%CI, 1.47-20.87; OR in non-Hispanics was 2.65, 95%CI, 0.95-7.34, compared with ERT use shorter than 17 months). In contrast, no significant association was observed for combined estrogen-progesterone use in either Hispanic or non-Hispanic women.

CONCLUSIONS

The results of this study indicated that postmenopausal women had significantly increased breast carcinoma risk for long-term ERT use. The risks among Hispanic women were substantially higher than among non-Hispanic white women although they were not statistically significant.