The association of hormone replacement therapy and coronary calcium as determined by electron beam tomography

Back to the future: Hormone replacement therapy as part of a prevention strategy for women at the onset of menopause

In the late 1980s, several observational studies and meta-analyses suggested that hormone replacement therapy (HRT) was beneficial for prevention of osteoporosis, coronary heart disease, dementia and decreased all-cause mortality. In 1992, the American College of Physicians recommended HRT for prevention of coronary disease. In the late 1990s and early 2000s, several randomized trials in older women suggested coronary harm and that the risks, including breast cancer, outweighed any benefit. HRT stopped being prescribed at that time, even for women who had severe symptoms of menopause. Subsequently, reanalyzes of the randomized trial data, using age stratification, as well as newer studies, and meta-analyses have been consistent in showing that younger women, 50-59 years or within 10 years of menopause, have decreased coronary disease and all-cause mortality; and did not have the perceived risks including breast cancer. These newer findings are consistent with the older observational data. It has also been reported that many women who abruptly stopped HRT had more risks, including more osteoporotic fractures. The current data confirm a "timing" hypothesis for benefits and risks of HRT, showing that younger have many benefits and few risks, particularly if therapy is predominantly focused on the estrogen component. We discuss these findings and put into perspective the potential risks of treatment, and suggest that we may have come full circle regarding the use of HRT. In so doing we propose that HRT should be considered as part of a general prevention strategy for women at the onset of menopause.

Anti-osteoporotic drugs and vascular calcification: the bidirectional calcium traffic

During the last years, numerous epidemiological studies have demonstrated a direct relationship between vascular calcification and low bone mineral density. This observation is in line with experimental data demonstrating the osteogenic characteristics of calcified arteries. Various common risk factors have been suggested to link vascular calcification and bone loss, including aging, estrogen deficiency, vitamin D and K deficiency, diabetes mellitus, renal failure, smoking, chronic inflammation and oxidative stress. Although the underlying pathogenetic mechanisms are not yet clear, current research is focusing on anti-osteoporotic agents that could potentially affect the deposition of calcium in the arterial wall and thus provide an additional therapeutic strategy in elderly osteoporotic women prone to calcific cardiovascular disease.

Physical activity, hormone replacement therapy, and the presence of coronary calcium in midlife women

BACKGROUND

Atherosclerotic calcification is a risk factor for cardiovascular events, independent of other traditional risk factors. Studies of the relation of menopausal hormone therapy to cardiovascular events have had inconsistent results, and often have been confounded by lifestyle behaviors and the "healthy user" effect. The authors evaluated the cross-sectional association of hormone therapy use with the presence and severity of atherosclerosis in postmenopausal women, independent of lifestyle factors, including diet and physical activity levels.

METHODS

The authors consecutively enrolled postmenopausal asymptomatic women who were referred for coronary artery calcium scanning to measure cardiovascular risk. After consent was obtained, women were interviewed prior to their cardiac scan about cardiac risk factors, hormone therapy use, menopausal status, diet, and physical activity. Coronary artery calcium prevalence was defined as any calcification present (score >0).

RESULTS

Of the 544 enrolled women aged 50-80 years, 252 (46.3%) were hormone therapy users. Hormone therapy users had a significantly lower prevalence of any coronary artery calcium (defined as coronary artery calcium score >0; 37%), than non-users (50%, p = 0.04), as well as significantly lower mean calcium scores (p = 0.02). Multiple logistic regression models demonstrated a significantly reduced odds of coronary artery calcium in hormone therapy users compared to non-users with an adjusted odds ratio of 0.58 (p = 0.04), adjusting for traditional cardiac risk factors and body mass index. Women who reported consuming a vegetarian or a high-protein diet had almost two-fold odds of coronary artery calcium compared with women who reported regular, mixed, or low-fat, low-salt diets (OR = 1.78, p = 0.02). Severity of coronary artery calcium was less with increasing levels of physical activity, and a significant association was observed between physical activity and hormone therapy use (adjusted OR = 4.05, p = 0.03), independent of coronary artery calcium severity.

CONCLUSION

This cross-sectional study demonstrated a protective association of hormone therapy with the presence and severity of coronary artery calcium. Although a strong relationship was observed between hormone therapy and physical activity, their complex interplay may affect mechanistic biochemical and physiological processes that have yet to be clearly delineated. Thus, physical activity and diet should be taken into account in prospective studies of the relation of hormone therapy use to coronary artery calcium.

The 2012 hormone therapy position statement of: The North American Menopause Society

OBJECTIVE

This position statement aimed to update the evidence-based position statement published by The North American Menopause Society (NAMS) in 2010 regarding recommendations for hormone therapy (HT) for postmenopausal women. This updated position statement further distinguishes the emerging differences in the therapeutic benefit-risk ratio between estrogen therapy (ET) and combined estrogen-progestogen therapy (EPT) at various ages and time intervals since menopause onset.

METHODS

An Advisory Panel of expert clinicians and researchers in the field of women's health was enlisted to review the 2010 NAMS position statement, evaluate new evidence, and reach consensus on recommendations. The Panel's recommendations were reviewed and approved by the NAMS Board of Trustees as an official NAMS position statement.

RESULTS

Current evidence supports the use of HT for perimenopausal and postmenopausal women when the balance of potential benefits and risks is favorable for the individual woman. This position statement reviews the effects of ET and EPT on many aspects of women's health and recognizes the greater safety profile associated with ET.

CONCLUSIONS

Recent data support the initiation of HT around the time of menopause to treat menopause-related symptoms and to prevent osteoporosis in women at high risk of fracture. The more favorable benefit-risk ratio for ET allows more flexibility in extending the duration of use compared with EPT, where the earlier appearance of increased breast cancer risk precludes a recommendation for use beyond 3 to 5 years.

Individualizing hormone therapy to minimize risk: accurate assessment of risks and benefits

Contrary to the exaggerated risks associated with HRT that developed after the initial press reports held by the Women's Health Initiative (WHI) writing group, the recent approach to hormone therapy is more balanced and evidence based. A review of over 40 years of scientific studies demonstrates that estrogen is a medication that can decrease mortality, cardiovascular disease, osteoporosis fracture, urogenital atrophy and dementia. When timing of administration, dose of therapy and route of administration are considered, estrogen is associated with low risks and substantial benefits. The decision of whether or not to take HRT for either short symptom relief or for long-term therapy, should be based on an accurate risk-benefit analysis. Adjusting the dose of therapy and considering a transdermal approach, particularly in high-risk patients, are important considerations.

Coronary Calcification and Hormones

The pathogenesis of coronary artery calcification and its role in atherogenesis has not been completely understood but is a new focus of interest in experimental and clinical research. Various bioactive substances, including hormones, have been implicated in the process of arterial calcification. This review considers the relationship between coronary artery calcification and hormones. These hormones may become therapeutic targets for the prevention of arterial calcification.

Oophorectomy, hormone therapy, and subclinical coronary artery disease in women with hysterectomy: the Women's Health Initiative coronary artery calcium study

OBJECTIVE

Surgical menopause has been associated with an increased risk of coronary heart disease events. In this study, we aimed to determine the associations between coronary artery calcium (CAC) and hysterectomy, oophorectomy, and hormone therapy use with a focus on the duration of menopause for which there was no hormone therapy use.

DESIGN

In a substudy of the Women's Health Initiative placebo-controlled trial of conjugated equine estrogens (0.625 mg/d), we measured CAC by computed tomography 1.3 years after the trial was stopped. Participants included 1,064 women with previous hysterectomy, aged 50 to 59 years at baseline. The mean trial period was 7.4 years. Imaging was performed at a mean of 1.3 years after the trial was stopped.

RESULTS

Mean age was 55.1 years at randomization and 64.8 years at CAC measurement. In the overall cohort, there were no significant associations between bilateral oophorectomy, years since hysterectomy, years since hysterectomy without taking hormone therapy (HT), years since bilateral oophorectomy, and years of HT use before Women's Health Initiative enrollment and the presence of CAC. However, there was a significant interaction between bilateral oophorectomy and prerandomization HT use for the presence of any CAC (P = 0.05). When multivariable analyses were restricted to women who reported no previous HT use, those with bilateral oophorectomy had an odds ratio of 2.0 (95% CI: 1.2-3.4) for any CAC compared with women with no history of oophorectomy, whereas among women with unilateral or partial oophorectomy, the odds of any CAC was 1.7 (95% CI: 1.0-2.8). Among women with bilateral oophorectomy, HT use within 5 years of oophorectomy was associated with a lower prevalence of CAC.

CONCLUSIONS

Among women with previous hysterectomy, subclinical coronary artery disease was more prevalent among those with oophorectomy and no prerandomization HT use, independent of traditional cardiovascular disease risk factors. The results suggest that factors related to oophorectomy and the absence of estrogen treatment in oophorectomized women may be related to coronary heart disease.

Post menopausal hormones and measures of subclinical atherosclerosis: the multi-ethnic study of atherosclerosis

OBJECTIVE

To evaluate whether post menopausal hormones are associated with atherosclerosis.

METHODS

We studied the relation of hormone use to coronary calcification and carotid intima-media thickness in a cross-sectional sample of 3245 post menopausal women, of whom 1620 had used hormones for various periods. Adjusted associations with three measures of hormone use (ever use, duration, and type of hormone) were estimated by multivariable regression.

RESULTS

The prevalence of coronary calcification was only 4 percentage points lower in women who had ever used hormones than in women who had not (40% versus 44%), and was not monotonically related to longer use: <2 years: 38%; 2-6 years: 36%; 6-13 years: 41%; >13 years: 48%. Similarly, duration of hormone use did not show a monotonic dose-response relation with the calcium score. Mean differences in carotid intima-media thickness according to categories of years of hormone use and type of hormone ranged from -0.10 mm to +0.08 mm, with no consistent patterns. Most adjusted associations were weak and sometimes contrary to our expectation.

CONCLUSIONS

We did not find meaningful associations between hormone use and subclinical atherosclerosis-neither to support benefit or harm, nor to support the prevailing theory of "healthy user" bias (namely, inverse associations due to residual confounding).

Estrogen therapy and coronary-artery calcification

BACKGROUND

Calcified plaque in the coronary arteries is a marker for atheromatous-plaque burden and is predictive of future risk of cardiovascular events. We examined the relationship between estrogen therapy and coronary-artery calcium in the context of a randomized clinical trial.

METHODS

In our ancillary substudy of the Women's Health Initiative trial of conjugated equine estrogens (0.625 mg per day) as compared with placebo in women who had undergone hysterectomy, we performed computed tomography of the heart in 1064 women aged 50 to 59 years at randomization. Imaging was conducted at 28 of 40 centers after a mean of 7.4 years of treatment and 1.3 years after the trial was completed (8.7 years after randomization). Coronary-artery calcium (or Agatston) scores were measured at a central reading center without knowledge of randomization status.

RESULTS

The mean coronary-artery calcium score after trial completion was lower among women receiving estrogen (83.1) than among those receiving placebo (123.1) (P=0.02 by rank test). After adjustment for coronary risk factors, the multivariate odds ratios for coronary-artery calcium scores of more than 0, 10 or more, and 100 or more in the group receiving estrogen as compared with placebo were 0.78 (95% confidence interval, 0.58 to 1.04), 0.74 (0.55 to 0.99), and 0.69 (0.48 to 0.98), respectively. The corresponding odds ratios among women with at least 80% adherence to the study estrogen or placebo were 0.64 (P=0.01), 0.55 (P<0.001), and 0.46 (P=0.001). For coronary-artery calcium scores of more than 300 (vs. <10), the multivariate odds ratio was 0.58 (P=0.03) in an intention-to-treat analysis and 0.39 (P=0.004) among women with at least 80% adherence.

CONCLUSIONS

Among women 50 to 59 years old at enrollment, the calcified-plaque burden in the coronary arteries after trial completion was lower in women assigned to estrogen than in those assigned to placebo. However, estrogen has complex biologic effects and may influence the risk of cardiovascular events and other outcomes through multiple pathways. (ClinicalTrials.gov number, NCT00000611.)

Hormone therapy and coronary artery calcification in asymptomatic postmenopausal women: the Rancho Bernardo Study

OBJECTIVE

To determine (1) whether past or current hormone therapy (HT) in postmenopausal women is associated with subclinical coronary artery plaque burden, (2) whether any association is independent of age, body size, blood pressure, lipids, fasting plasma glucose, cigarette smoking, leisure time physical activity, alcohol intake, use of lipid-lowering medications, and socioeconomic status, and (3) whether any association varies by duration of HT or by the use of combined versus unopposed HT.

DESIGN

An observational study, with HT validated and coronary heart disease risk factors determined between 1997 and 1999 in a research clinic, and coronary artery calcium score (CACS) evaluated by electron beam computed tomography in 2001 through 2002. Participants were 204 community-dwelling postmenopausal women from the Rancho Bernardo cohort aged 55 to 78 years with no history of heart disease.

RESULTS

The odds of severe CACS in current estrogen users (n = 127) was 0.40 (95% CI 0.19, 0.82), controlling for all covariates. Past users (n = 40) had intermediate odds (multiply adjusted OR = 0.66, 95% CI = 0.28, 1.58). In subgroup analyses, age-adjusted associations did not differ between the 68 women using unopposed estrogen versus the 59 using an estrogen-progestin regimen. Women who had used HT for at least 10 years (n = 86) had significantly less (P = 0.01) plaque burden than shorter term users (n = 41).

CONCLUSIONS

Both the strong association and the duration of use effect independent of lifestyle and social class suggest an antiatherogenic effect of postmenopausal estrogen. Only a clinical trial can completely exclude confounding by social class, lifestyle, and unmeasured covariates.

Progression of coronary calcification in healthy postmenopausal women

Background

Coronary artery calcium score incrementally improves coronary risk prediction beyond that provided by conventional risk factors. Limited information is available regarding rates of progression of coronary calcification in women, particularly those with baseline scores above zero. Further, determinants of progression of coronary artery calcification in women are not well understood. This study prospectively evaluated rates and determinants of progression of coronary artery calcium score in a group of healthy postmenopausal women.

Methods

We determined coronary calcium score by computed tomography and recorded demographic, lifestyle and health characteristics of 914 postmenopausal women, a subset of those enrolled in the Women's Health Initiative Observational Study. The 305 women with calcium score ≥10 Agatston units at baseline were invited for repeat scan. This analysis includes the 94 women who underwent second scans.

Results

Mean age of study participants was 65 ± 9 years (mean ± SD), body mass index was 26.1 ± 6.1 kg/m², and baseline calcium score was 162 ± 220 Agatston units. Mean interval between scans was 3.3 ± 0.7 years. A wide range of changes in coronary calcium score was observed, from -53 to +452 Agatston units/year. Women with lower scores at baseline had smaller annual increases in absolute calcium score. Coronary calcium scores increased 11, 31 and 79 Agatston units/year among women with baseline calcium score in the lowest, middle and highest tertiles. In multivariate analysis, age was not an independent predictor of absolute change in coronary calcium score. Hydroxymethylglutaryl coenzyme A reductase inhibitor (statin) use at baseline was a negative predictor (p = 0.015), whereas baseline calcium score was a strong, positive predictor (p < 0.0001) of progression of coronary calcification.

Conclusion

Among postmenopausal women with coronary calcium score ≥ 10 Agatston units, rates of change of coronary calcium score varied widely. In multivariate analysis, statin use was a negative independent determinant, whereas baseline calcium score was a strong positive predictor of annual change in coronary calcium score.