Hormone replacement therapy in postmenopausal women

Lipoxin and glycation in SREBP signaling: Insight into diabetic cardiomyopathy and associated lipotoxicity

Diabetes and cardiovascular diseases are the leading cause of morbidity and mortality worldwide. Diabetes increases cardiovascular risk through hyperglycemia and atherosclerosis. Chronic hyperglycemia accelerates glycation reaction, which forms advanced glycation end products (AGEs). Additionally, hyperglycemia with enhanced levels of cholesterol, native and oxidized low-density lipoproteins, free fatty acids, and oxidative stress induces lipotoxicity. Accelerated glycation and disturbed lipid metabolism are characteristic features of diabetic heart failure. SREBP signaling plays a significant role in lipid and glucose homeostasis. AGEs increase lipotoxicity in diabetic cardiomyopathy by inhibiting SREBP signaling. While anti-inflammatory lipid mediators, lipoxins resolve inflammation caused by lipotoxicity by upregulating the PPARγ expression and regulating CD36. PPARγ connects the bridge between glycation and lipoxin in SREBP signaling. A summary of treatment modalities against diabetic cardiomyopathy is given in brief. This review indicates the novel therapeutic approach in the crosstalk between glycation and lipoxin in SREBP signaling.

The preventive effect of Cuscutae Semen polysaccharide on bone loss in the ovariectomized rat model

The seed of Cuscutae Semen has been used as a functional food to prevent osteoporosis and aging, and improve sexual function in Traditional Chinese Medicine. However, there is a little report on its beneficial effects on osteoporosis. The purpose of our study was to explore whether Cuscutae Semen polysaccharide (CSP) could prevent osteoporosis induced by estrogen deficiency in the ovariectomized rat model. The preventive effect of CSP was assessed using the ovariectomized (OVX) rat model by treatment with vehicle or CSP for 12 weeks. Serum indexes related to osteogenesis were measured using ELISA kits. The underlying mechanism of action of CSP was evaluated by qRT-PCR. The findings showed that CSP exerted bone protective effects via the increase of bone mass, BMD, IGF, TGF-β, osteocalcin, and osteoprotegerin, and the decrease of TRAP and CTX levels in estrogen deficiency-induced osteoporosis, which is mediated by up-regulating the expression levels of Osterix, BMP-2, Runx2, and Smad5 and down-regulating the expression levels of TRAP, NFATc1, c-Fos, and cathepsin K. These findings suggested that CSP exhibited the preventive effects in the estrogen deficiency-induced osteoporosis via promoting bone formation and inhibiting bone resorption. Therefore, CSP may be developed as a promising agent for the prevention of estrogen deficiency-induced osteoporosis.

Hepatic Estrogen Sulfotransferase Distantly Sensitizes Mice to Hemorrhagic Shock-Induced Acute Lung Injury

Hemorrhagic shock (HS) is a potential life-threatening condition that may lead to injury to multiple organs, including the lung. The estrogen sulfotransferase (EST, or SULT1E1) is a conjugating enzyme that sulfonates and deactivates estrogens. In this report, we showed that the expression of Est was markedly induced in the liver but not in the lung of female mice subject to HS and resuscitation. Genetic ablation or pharmacological inhibition of Est effectively protected female mice from HS-induced acute lung injury (ALI), including interstitial edema, neutrophil mobilization and infiltration, and inflammation. The pulmonoprotective effect of Est ablation or inhibition was sex-specific, because the HS-induced ALI was not affected in male Est-/- mice. Mechanistically, the pulmonoprotective phenotype in female Est-/- mice was accompanied by increased lung and circulating levels of estrogens, attenuated pulmonary inflammation, and inhibition of neutrophil mobilization from the bone marrow and neutrophil infiltration to the lung, whereas the pulmonoprotective effect was abolished upon ovariectomy, suggesting that the protection was estrogen dependent. The pulmonoprotective effect of Est ablation was also tissue specific, as loss of Est had little effect on HS-induced liver injury. Moreover, transgenic reconstitution of human EST in the liver of global Est-/- mice abolished the pulmonoprotective effect, suggesting that it is the EST in the liver that sensitizes mice to HS-induced ALI. Taken together, our results revealed a sex- and tissue-specific role of EST in HS-induced ALI. Pharmacological inhibition of EST may represent an effective approach to manage HS-induced ALI.

Plant Extracts in the Bone Repair Process: A Systematic Review

Bone lesions are an important public health problem, with high socioeconomic costs. Bone tissue repair is coordinated by an inflammatory dynamic process mediated by osteoprogenitor cells of the periosteum and endosteum, responsible for the formation of a new bone matrix. Studies using antioxidant products from plants for bone lesion treatment have been growing worldwide. We developed a systematic review to compile the results of works with animal models investigating the anti-inflammatory activity of plant extracts in the treatment of bone lesions and analyze the methodological quality of the studies on this subject. Studies were selected in the PubMed/MEDLINE, Scopus, and Web of Science databases according to the PRISMA statement. The research filters were constructed using three parameters: animal model, bone repair, and plant extracts. 31 full-text articles were recovered from 10 countries. Phytochemical prospecting was reported in 15 studies (48.39%). The most common secondary metabolites were flavonoids, cited in 32.26% studies (n = 10). Essential criteria to in vivo animal studies were frequently underreported, suggesting publication bias. The animals treated with plant extracts presented positive results in the osteoblastic proliferation, and consequently, this treatment accelerated osteogenic differentiation and bone callus formation, as well as bone fracture repair. Possibly, these results are associated with antioxidant, regenerative, and anti-inflammatory power of the extracts. The absence or incomplete characterization of the animal models, treatment protocols, and phytochemical and toxicity analyses impairs the internal validity of the evidence, making it difficult to determine the effectiveness and safety of plant-derived products in bone repair.

Discovery of a tetrazolyl β-carboline with in vitro and in vivo osteoprotective activity under estrogen-deficient conditions

β-Carbolines have been assessed for osteoclastogenesis. However, their effect on osteoblasts during estrogen deficiency is still unclear. Here, a series of novel piperazine and tetrazole tag β-carbolines have been synthesized and examined for osteoblast differentiation in vitro. In vitro data suggest that compound 8g is the most promising osteoblast differentiating agent that was evaluated for in vivo studies. Compound 8g promoted osteoblast mineralization, stimulated Runx2, BMP-2 and OCN expression levels, increased BrdU incorporation and inhibited generation of free radicals as well as nitric oxide. Since a piperazine group is involved in bone repair activity and β-carboline in IκB kinase (IKK) inhibition, compound 8g inhibited tumor necrosis factor α (TNFα) directed IκBα phosphorylation, preventing nuclear translocation of NF-κB thereby alleviating osteoblast apoptosis. In vivo studies show that compound 8g was able to restore estrogen deficiency-induced bone loss in ovariectomized rats without any toxicity, thus signifying its potential in bone-protection chemotherapy under postmenopausal conditions.

Heartwood extract from Dalbergia sissoo promotes fracture healing and its application in ovariectomy-induced osteoporotic rats

OBJECTIVES

This study was undertaken to investigate the effects of a heartwood ethanolic extract (HEE) made from the Dalbergia sissoo on facture healing and in the prevention of pathological bone loss resulting from estrogen deficiency in ovariectomized (Ovx) rats.

METHODS

Heartwood ethanolic extract (250, 500 and 1000 mg/kg per day) was administered orally immediately next day after drill-hole injury and continued for 2 weeks. Ovx rats received HEE at same doses for 12 weeks and compared with 17-β estradiol (E2; 100 μg/kg for 5 days/week subcutaneously) group. Confocal imaging for fracture healing, micro-architecture of long bones, biomechanical strength, formation of mineralized nodule by bone marrow osteoprogenitor cells, bone turnover markers and gene expression were studied. One-way ANOVA was used to test significance.

KEY FINDINGS

Heartwood ethanolic extract treatment promoted fracture healing, formation of new bone at the drill-hole site and stimulated osteogenic genes at callus region. HEE administration to the Ovx rats exhibited better micro-architectural parameters at various anatomical positions, better bone biomechanical strength and more osteoprogenitor cells in the bone marrow compared with Ovx + vehicle group. HEE exhibited no uterine estrogenicity.

CONCLUSIONS

Oral administration of HEE was found to promote fracture healing and exhibited osteoprotective effect by possibly stimulation of osteoblast function.

Estrogen Sulfotransferase Is an Oxidative Stress-responsive Gene That Gender-specifically Affects Liver Ischemia/Reperfusion Injury

Estrogen sulfotransferase (EST) regulates estrogen homeostasis by sulfonating and deactivating estrogens. Liver ischemia and reperfusion (I/R) involves both hypoxia during the ischemic phase and oxidative damage during the reperfusion phase. In this report, we showed that the expression of EST was markedly induced by I/R. Mechanistically, oxidative stress-induced activation of Nrf2 was responsible for the EST induction, which was abolished in Nrf2(-/-) mice. EST is a direct transcriptional target of Nrf2. In female mice, the I/R-responsive induction of EST compromised estrogen activity. EST ablation attenuated I/R injury as a result of decreased estrogen deprivation, whereas this benefit was abolished upon ovariectomy. The effect of EST ablation was sex-specific because the EST(-/-) males showed heightened I/R injury. Reciprocally, both estrogens and EST regulate the expression and activity of Nrf2. Estrogen deprivation by ovariectomy abolished the I/R-responsive Nrf2 accumulation, whereas the compromised estrogen deprivation in EST(-/-) mice was associated with increased Nrf2 accumulation. Our results suggested a novel I/R-responsive feedback mechanism to limit the activity of Nrf2 in which Nrf2 induces the expression of EST, which subsequently increases estrogen deactivation and limits the estrogen-responsive activation of Nrf2. Inhibition of EST, at least in females, may represent an effective approach to manage hepatic I/R injury.

Comparison of associations of body mass index, abdominal adiposity, and risk of colorectal cancer in a large prospective cohort study

BACKGROUND

Increased body mass index (BMI) is an established colorectal cancer risk factor. High waist circumference or waist-hip-ratio (WHR) may better reflect an abnormal metabolic state and be more predictive of colorectal cancer risk than BMI.

METHODS

We examined BMI, waist circumference, WHR, and hip circumference in relation to colorectal cancer risk among 203,177 participants followed for 10 years. We derived standardized colorectal cancer risk estimates for each anthropometric parameter and compared predictive characteristics (Harrell's C-index). In women, we examined whether hormone replacement therapy (HRT) use modified the associations between anthropometric measures and colorectal cancer.

RESULTS

We ascertained 2,869 colorectal cancers. In men, increased colon cancer risks were associated with BMI [HR per SD, 1.14; 95% confidence interval (CI), 1.08-1.20], waist circumference (HR per SD, 1.17; 95% CI, 1.08-1.27), and WHR (HR per SD, 1.09; 95% CI, 1.04-1.14). In women, anthropometric variables were unrelated to colon cancer. For men and women, anthropometric variables were unrelated to rectal cancer. Compared with BMI, waist circumference and WHR did not materially influence colon cancer prediction models [C-index changes: -0.0041 and 0.0046 (men); 0.0004 and 0.0005 (women)]. In current HRT users, colon cancer was inversely or suggestively inversely associated with waist circumference (HR per SD, 0.78; 95% CI, 0.63-0.97) and WHR (HR per SD, 0.88; 95% CI, 0.76-1.01), but positively related to hip circumference (HR per SD, 1.39; 95% CI, 1.13-1.71).

CONCLUSION

BMI, waist circumference, and WHR show comparable positive associations with colon cancer in men. Associations between anthropometric measures and colon cancer are weak or null in women, but there is some evidence for effect modification by HRT.

IMPACT

These findings may improve our understanding of the relation of adiposity to colorectal cancer.

Hormone-dependent aging problems in women

One of the major social issues nowadays is the aging society. Korea is already an aging society, and 63 cities and districts are ultra-aged societies where the rate of people older than 65 yr exceeds 20%. Among them, more than 67% are women. These statistics reveal the importance of healthcare for older women. Disease and disability of older women are very closely related to the loss of female sex hormones after menopause. Major hormone-dependent aging problems in women such as osteoporosis, Alzheimer's disease (AD), urinary incontinence, and coronary atherosclerosis were surveyed in this review, and the key role of hormones in those diseases and hormone replacement therapy (HRT) were summarized. We expect that this review would provide some understanding of factors that must be considered to give optimal care to older women for healthy lives.

Which Gender is Better Positioned in the Process of Liver Surgery? Male or Female?

Liver surgery is a process which induces various types of stress on the liver including the total occlusion of the blood inflow, hemorrhage, massive volume reduction, and postoperative infection. Animal studies have shown a gender dimorphic response of the liver for various stresses such as ischemia/reperfusion, hemorrhage/resuscitation, hepatectomy, portal branch ligation, and endotoxemia. Most of these studies demonstrated the female liver to be more tolerant under stressful conditions than the male liver. Estrogen, which is a representative female sex hormone, may be one of the responsible factors for this gender dimorphism. The mechanism of estrogen's salutary effect includes circulatory improvement, a reduced inflammatory response, a reduced oxygen radical production, and an improved hepatic regeneration. However, the clinical evidence that supports the results of these experimental studies is still insufficient. A well-controlled prospective clinical study is necessary to clarify the role of gender or sex hormone in the process of liver surgery. This may not only lead to a deeper understanding of the liver pathophysiology, but also to the possibility of hepatoprotective therapy using sex hormone modulators. This review summarizes the current understanding of gender dimorphism in the tolerance of the liver to various hepatic stresses, which occur during the process of major liver surgery.

Do endocrine treatments for breast cancer have a negative impact on lipid profiles and cardiovascular risk in postmenopausal women?

Although cardiovascular disease occurs infrequently in premenopausal women, the incidence increases dramatically after menopause. Endocrine agents used to treat postmenopausal women with breast cancer further reduce estrogen levels and have the potential to adversely affect lipid metabolism, although the relevance of this to cardiovascular risk remains uncertain. Until recently, the standard endocrine treatment for breast cancer was tamoxifen, which appears to have a generally favorable effect on lipid parameters, although this does not translate into cardioprotective effects. The third-generation aromatase inhibitors (AIs), including anastrozole, have recently emerged as alternatives for the treatment of postmenopausal women with hormone-sensitive breast cancer. Anastrozole, currently the only AI with established long-term safety data in the adjuvant setting, results in significantly fewer thromboembolic and cerebrovascular events compared with tamoxifen, and a similar incidence of ischemic cardiovascular events. However, the effects of other AIs on lipid values are variable, and any relationship with cardiovascular events in long-term studies is currently unknown.

Synthesis of Nitric Oxide in Human Osteoblasts in Response to Physiologic Stimulation of Electrotherapy

Electrotherapy for bone healing, remodeling and wound healing may be mediated by modulation of nitric oxide (NO). Using NO-specific fluorophore (DAF-2), we report here that application of non-invasive, physiologic electrical stimulation induces NO synthesis in human osteoblasts, and that such NO generation is comparable to that induced by estrogen treatment. For example, application of a sinusoidal 1 Hz, 2 V/cm (peak to peak) electrical stimulation (ES) increases NO-bound DAF-2 fluorescence intensity by a 2-fold within 60 min exposure by activating nitric oxide synthase (NOS). Increase in the NO level is found to depend critically on the frequency and strength of ES. While the frequency of 1 Hz ES seems optimal, the ES strength >0.5 V/cm is required to induce significant NO increase, however. Nitric oxide synthesis in response to ES is completely prevented by blocking estrogen receptors using a competitive inhibitor, suggesting that NO generation is likely initiated by activation of estrogen receptors at the cell surface. Based on these findings, physiologic stimulation of electrotherapy appears to represent a potential non-invasive, non-genomic, and novel physical technique that could be used to regulate NO-mediated bone density and facilitate bone remodeling without adverse effects associated with hormone therapy.

Chapter 4: Changing Patterns in Breast Cancer Incidence Trends

Incidence rates for breast cancer in U.S. women have steadily increased for decades, but the reasons are not well understood. A recent upturn in these trends suggests that one component may be the effect of more aggressive screening in the population. The age-period-cohort framework, in which the temporal components associated with year of diagnosis and generation are evaluated, can assist in interpreting the elements associated with these trends. A unique approach for exploring other ways of partitioning the contribution of the different temporal components is described and applied to breast cancer incidence data (ICDO 174.0-174.9) from the Surveillance, Epidemiology and End Results (SEER) registries. Single-year intervals for age and year of diagnosis were used to fit models that provide estimates of the trends associated with the individual temporal elements. A log-linear model for age, period, and cohort was fitted using Poisson regression, and estimates of the separate time trends were calculated. The trends with period increased after 1982, when more aggressive screening began, and the trend is steeper for women older than 40 years. Cohort trends have increased steadily, although recent cohorts appear to be somewhat flat for women aged 50 years or younger, whereas the trend for those older than 50 years have continued to increase. Estimates of cohort trends in rates are also provided by extrapolating what would have occurred had there been no period trend before or after 1982, thus providing an estimate of the magnitude of the upturn that occurred after the recent emphasis on screening.

Postmenopausal hormone therapy and cardiovascular disease: An overview of main findings

Cardiovascular disease has emerged as a leading cause of death in women. In recent years, significant attention has been paid to the potential benefits of hormone therapy on chronic diseases such as cardiovascular disease. Large prevention trials failed to confirm the cardioprotective effect of estrogen. The divergent findings from observational and randomized clinical studies are summarized and reasons for the different results are postulated. Use of estrogen alone or estrogen opposed with progestins is not indicated for the prevention of cardiovascular disease and may even increase the risk of stroke. Oral estrogen increases venous thromboembolism events. Recent data suggest that transdermal estrogens are safe with respect to venous thromboembolism. Current data have limited ability to investigate the wide variety of hormone treatments available. Clinical research should be continued to assist patients and clinicians in making treatment decisions on the basis of an individual's benefits and risks.

Effects of a Low-Fat, High-Fiber Diet and Exercise Program on Breast Cancer Risk Factors In Vivo and Tumor Cell Growth and Apoptosis In Vitro

The present study investigated the effects of a diet and exercise intervention on known breast cancer (BCa) risk factors, including estrogen, obesity, insulin, and insulin-like growth factor-I (IGF-I), in overweight/obese, postmenopausal women. In addition, using the subjects' pre- and postintervention serum in vitro, serum-stimulated growth and apoptosis of three estrogen receptor-positive BCa cell lines were studied. The women where placed on a low-fat (10-15% kcal), high-fiber (30-40 g per 1,000 kcal/day) diet and attended daily exercise classes for 2 wk. Serum estradiol was reduced in the women on hormone treatment (HT; n = 28) as well as those not on HT (n = 10). Serum insulin and IGF-I were significantly reduced in all women, whereas IGF binding protein-1 was increased significantly. In vitro growth of the BCa cell lines was reduced by 6.6% for the MCF-7 cells, 9.9% for the ZR-75-1 cells, and 18.5% for the T-47D cells. Apoptosis was increased by 20% in the ZR-75-1 cells, 23% in the MCF-7 cells, and 30% in the T-47D cells (n = 12). These results show that a very-low-fat, high-fiber diet combined with daily exercise results in major reductions in risk factors for BCa while subjects remained overweight/obese. These in vivo serum changes slowed the growth and induced apoptosis in serum-stimulated BCa cell lines in vitro.

Effects of daidzein, genistein, and 17beta-estradiol on 7,12-dimethylbenz[a]anthracene-induced mutagenicity and uterine dysplasia in ovariectomized rats

Phytoestrogens, primarily isoflavones daidzein (DZ) and genistein (GE), are increasingly used by postmenopausal women as an alternative to hormone replacement therapy due to reports that estrogen therapy increases the risk of breast and endometrial cancers. These compounds, as estrogen receptor agonists, may influence chemical carcinogenesis in estrogen-responsive tissues such as the uterus. We utilized ovariectomized (OVX) rats to model menopause and assessed the effects of dietary DZ, GE, or 17beta-estradiol (E2) on carcinogen-induced mutagenesis and carcinogenesis in the rat uterus. Big Blue transgenic rats (derived from Fischer 344 strain) were exposed to 7,12-dimethylbenz[a]anthracene (DMBA) in the presence or absence of the supplements. At 16- or 20-wk sacrifice, the uteri were removed and processed to determine mutant frequencies (MFs) and immunohistochemical or histopathological parameters, respectively. In rats treated with DMBA alone, a significant increase in lacI MFs (P < 0.01) in both OVX and intact (INT) rats was observed. The DMBA-induced MFs were not significantly altered by dietary DZ, GE, or E2 in both OVX and INT rats. Although dysplasia was not induced in the uterus of OVX and INT rats treated with DMBA alone, it was detected in 55% of OVX rats fed E2 alone and in 100% of OVX rats fed E2 along with DMBA exposure. Cell proliferation also was significantly higher in OVX rats fed E2 and treated with DMBA. In rats fed the isoflavones and treated with DMBA, the incidence of dysplasia was either reduced or virtually absent in both OVX and INT groups. These results indicate that a high incidence of dysplasia was associated with E2 feeding with or without DMBA treatment in the OVX rats, whereas the incidence was low in rats fed DZ or GE and treated with DMBA, suggesting a weak estrogen receptor agonist of DZ or GE in the rat uterus. The absence of dysplasia in OVX rats exposed to DMBA alone also suggests, in part, a promotional mechanism via estrogen- or isoflavone-driven cell proliferation.

Mineral changes in osteoporosis: a review

Bone mineral composition, crystallinity, and bone mineral content of osteoporotic patients are different from those of normal subjects. We review the evidence that these mineralization parameters contribute to the strength (fracture resistance) of bone and the methods that have been used to examine them. A specific example is provided from analysis of biopsies from the Multiple Outcomes in Raloxifene Evaluation trial. For the analyses, randomly selected biopsies from placebo, low-dose, and high-dose groups (n = 5 per group) obtained at time zero and 2 years after treatment were examined by infrared imaging spectroscopy. In all cases, comparable increases in mineral content were found, but there were no significant variations in mineral crystallinity.

Metal complex SERMs (selective oestrogen receptor modulators). The influence of different metal units on breast cancer cell antiproliferative effects

The selective oestrogen receptor modulator tamoxifen is a leading agent in the adjuvant treatment of breast cancer. Several organometallic moieties have been vectorised with tamoxifen, in order to improve on the latter's antiproliferative properties by the addition of a potentially cytotoxic moiety, and have been evaluated versus both oestrogen receptor positive (MCF7) and oestrogen receptor negative (MDA-MB231) breast cancer cells. For tamoxifen analogues with ((R,R)-trans-1,2-diaminocyclohexane)platinum(II), cyclopentadienyl rhenium tricarbonyl, and ruthenocene tethers, there was no enhancement of the antiproliferative effect on oestrogen receptor positive cells, nor any cytotoxic effect on oestrogen receptor negative cells, while those containing cyclopentadienyl titanium dichloride showed an oestrogenic effect. However, compounds where ferrocene replaces tamoxifen's phenyl ring were strongly cytotoxic against both cell lines. The synthesis and biological results of these compounds is reviewed and placed in the historic context of inorganic compounds in therapy.

Current Understanding of Gender Dimorphism in Hepatic Pathophysiology1

Studies have shown gender dimorphic response of the liver for various hepatic stresses including ischemia/reperfusion, hemorrhagic shock-resuscitation, hepatectomy, liver cirrhosis, endotoxemia, and chronic alcoholic consumption. The mechanisms responsible for the gender dimorphic response include differences in pro-inflammatory cytokine release, production of reactive oxygen species, and alteration in hepatic vasoregulatory action. These effects were shown to be modulated by circulating sex steroid levels. In this regard, modulation of sex steroid levels by agents/drugs has been proposed as a therapeutic option for preventing hepatic damage in various hepatic stress models. Further elucidation of precise mechanisms responsible for the gender-related differences in the hepatic pathophysiology is essential for the potential clinical application of sex hormone modulation therapy. In this article, current progress in our understanding the gender difference in the hepatic pathophysiology under the condition of hepatic stress is reviewed and discussed.

Relation between homocysteine and B-vitamin status indicators and bone mineral density in older Americans

Recent studies have found a connection between hyperhomocysteinemia and hip fracture. If this association is causal, it could be mediated through detrimental effects of low B-vitamin status on bone mineral density (BMD). Studies have linked homocysteine (Hcy) and the established Hcy determinants folate and vitamin B12, to BMD, but results have been inconsistent. Furthermore, only one study considered the specific marker of tissue vitamin B12 status, methylmalonic acid (MMA), and none have considered red blood cell (RBC) folate. To further explore associations between Hcy and B-vitamin status indicators and bone health, we used data collected on older (i.e., aged >55 years) men and women who underwent DEXA scans of the hip as participants in phase 2 of the third U.S. National Health and Nutrition Examination Survey (n = 1550). We used BMD at the total hip as a continuous outcome variable in some analyses. In others, we used osteoporosis defined on a sex- and race/ethnicity-specific basis according to World Health Organization (WHO) guidelines. After adjusting for demographic factors, body mass index, and other osteoporosis risk factors, BMD decreased and osteoporosis increased significantly with increasing serum MMA quartile category (P < 0.01). Serum vitamin B12 was related to BMD in dose-response fashion up to about 200 pmol/L, and subjects with serum Hcy > or = 20 micromol/L had significantly lower BMD than subjects with serum Hcy < 10 micromol/L. Furthermore, the OR (95% CI) relating a serum vitamin B12 concentration below the 25th percentile to osteoporosis/osteopenia was 2.0 (1.0-3.9), and dose-response trends relating both serum B12 and Hcy to this outcome were marginally statistically significant. Neither serum nor RBC folate was related to BMD or osteoporosis. We conclude that Hcy and vitamin B12 status indicators are associated with BMD in older Americans. Whether this association reflects a causal relation remains unclear and merits further study in light of age-related declines in B12 status and BMD, and the need for low-risk, easily implemented strategies for osteoporosis prevention.

Effects of Hormone Replacement on Progression of Coronary Calcium as Measured by Electron Beam Tomography

PURPOSE

The recent Women's Health Initiative (WHI) results have demonstrated that combined estrogen plus progestin imparts a small but significant increase in cardiovascular risk and breast cancer among asymptomatic women. However, the effect and potential benefit of unopposed estrogen is not as clear. We sought to evaluate the progression of subclinical atherosclerosis in postmenopausal women using no hormone replacement therapy (HRT), combined therapy, and estrogen alone in an observational study.

METHODS

Postmenopausal women without symptoms or known coronary heart disease (CHD) were evaluated at our center for follow-up of coronary calcification. Patients were physician referred and underwent two consecutive electron beam tomography scans at least 1 year apart. All women fitting the study criteria were asked to participate, and those who consented were included. Demographic data, risk factors for CHD, HRT, and other medication use were collected by interview.

RESULTS

The study included 177 asymptomatic women. Calcium progression was 14.6%+/-21% in women taking any hormone therapy (n=97). Annual calcium progression rates in nonusers (n=80) was 22.3%+/-32%. Relative to the nonuser group, HRT treatment inhibited the progression of atherosclerosis by 35% (p=0.01). This effect was independent of age, risk, cardiovascular factors, statin use, or baseline CAC score. Thirty-five of the 97 women (36%) were taking estrogen plus progestin, with an annual increase in calcium scores of 24%+/-23%, similar to the non-HRT women (22%). Those women taking estrogen replacement only (n=62) was 63% lower (9%+/-22%).

CONCLUSIONS

This is an observational study, and the results are in accordance with the recently published WHI study, demonstrating no benefit of estrogen plus progestin compared with no therapy. However, women taking unopposed estrogen demonstrated a significant slowing of subclinical atherosclerosis compared with non-HRT and estrogen plus progestin.