The timing of initiation of hormone therapy may influence its effect on cardiovascular disease.To explore whether the effects of hormone therapy on risk of cardiovascular disease vary by age or years since menopause began.Secondary analysis of the Women's Health Initiative (WHI) randomized controlled trials of hormone therapy in which 10,739 postmenopausal women who had undergone a hysterectomy were randomized to conjugated equine estrogens (CEE) or placebo and 16,608 postmenopausal women who had not had a hysterectomy were randomized to CEE plus medroxyprogesterone acetate (CEE + MPA) or placebo. Women aged 50 to 79 years were recruited to the study from 40 US clinical centers between September 1993 and October 1998.Statistical test for trend of the effect of hormone therapy on coronary heart disease (CHD) and stroke across categories of age and years since menopause in the combined trials.In the combined trials, there were 396 cases of CHD and 327 cases of stroke in the hormone therapy group vs 370 [corrected] cases of CHD and 239 cases of stroke in the placebo group. For women with less than 10 years since menopause began, the hazard ratio (HR) for CHD was 0.76 (95% confidence interval [CI], 0.50-1.16); 10 to 19 years, 1.10 (95% CI, 0.84-1.45); and 20 or more years, 1.28 (95% CI, 1.03-1.58) (P for trend =.02). The estimated absolute excess risk for CHD for women within 10 years of menopause was -6 per 10,000 person-years; for women 10 to 19 years since menopause began, 4 per 10,000 person-years; and for women 20 or more years from menopause onset, 17 per 10,000 person-years. For the age group of 50 to 59 years, the HR for CHD was 0.93 (95% CI, 0.65-1.33) and the absolute excess risk was -2 per 10,000 person-years; 60 to 69 years, 0.98 (95% CI, 0.79-1.21) and -1 per 10,000 person-years; and 70 to 79 years, 1.26 (95% CI, 1.00-1.59) and 19 per 10,000 person-years (P for trend =.16). Hormone therapy increased the risk of stroke (HR, 1.32; 95% CI, 1.12-1.56). Risk did not vary significantly by age or time since menopause. There was a nonsignificant tendency for the effects of hormone therapy on total mortality to be more favorable in younger than older women (HR of 0.70 for 50-59 years; 1.05 for 60-69 years, and 1.14 for 70-79 years; P for trend =.06).Women who initiated hormone therapy closer to menopause tended to have reduced CHD risk compared with the increase in CHD risk among women more distant from menopause, but this trend test did not meet our criterion for statistical significance. A similar nonsignificant trend was observed for total mortality but the risk of stroke was elevated regardless of years since menopause. These data should be considered in regard to the short-term treatment of menopausal symptoms.clinicaltrials.gov Identifier: NCT00000611.

Estrogen increases endothelium-dependent vasodilation in postmenopausal women. However, use of progestins in combination with estrogen may counter beneficial effects of estrogen on endothelium. We investigated the effect of medroxyprogesterone acetate (MPA) on estrogen-induced increase in endothelium-dependent vasodilation in postmenopausal women.Postmenopausal women were treated daily with conjugated equine estrogen (CEE) 0.625 mg (n=14), CEE 0.625 mg and MPA 2.5 mg (n=15) or CEE 0.625 mg and MPA 5.0 mg (n=16) for 3 months. Plasma lipids and hormones were measured before and after treatment. Vasodilatory responses of the brachial artery were evaluated by measuring flow-mediated vasodilation (FMD) and nitroglycerin-induced vasodilation by use of high-resolution ultrasonography. Susceptibility of LDL to oxidation was analyzed by incubation with CuSO(4) while kinetics of conjugated diene formation was monitored. Plasma total and LDL cholesterol concentrations were decreased significantly in all groups. CEE increased FMD significantly, from 4.5+/-1.7% to 8.5+/-2.8% (P<0.001). Addition of MPA reversed this effect in a concentration-dependent manner (for MPA 2.5 mg, from 5.0+/-3.2% to 6.2+/-3.1%; for MPA 5.0 mg, from 4.9+/-3.4% to 3.6+/-3.7%; P=NS for each). No treatment significantly altered nitroglycerin-induced dilation. Lag time for conjugated diene formation was prolonged significantly in all groups, and the oxidation rate was significantly reduced.Concurrent MPA administration may offset favorable effects of estrogen on endothelial function in postmenopausal women. Because MPA did not diminish LDL-lowering and antioxidant effects of estrogen, MPA-induced inhibition of endothelium-dependent vasodilation may be independent of changes in oxidative susceptibility and plasma concentration of LDL.

Estro-progestin treatments have been associated with an increased risk of thromboembolic events in postmenopausal women. This study examined whether progestins affect the stimulatory effect of estrogens on the endothelial formation of nitric oxide (NO), a potent antithrombotic factor.Experiments were performed with human endothelial cells. Endothelial NO synthase (eNOS) and GTP cyclohydrolase I (GTPCH I) mRNA expression was assessed by RT-PCR, eNOS protein by Western blotting, NO formation by electron spin resonance spectroscopy, and platelet aggregation by an aggregometer. Medroxyprogesterone acetate (MPA), progesterone, levonorgestrel, and nomegestrol acetate prevented the 17beta-estradiol (17beta-E)-induced expression of eNOS mRNA and protein. MPA and progesterone reduced the 17beta-E-induced formation of NO and potentiation of the inhibitory effect of endothelial cells on platelet aggregation whereas levonorgestrel and nomegestrol acetate were without effect. Moreover, MPA and progesterone prevented the 17beta-E-induced expression of GTPCH I mRNA. Mifepristone, a glucocorticoid and progesterone receptor antagonist, and L-sepiapterin prevented the inhibitory effect of MPA and progesterone on platelet aggregation.Certain progestins, including MPA, attenuate the 17beta-E-induced NO-mediated inhibition of platelet aggregation by endothelial cells through preventing both eNOS and GTPCH I expression most likely via activation of glucocorticoid receptors.

Menopausal hormone therapy (HT) was widely used in the past, but with the publication of seminal primary and secondary prevention trials that reported an excess cardiovascular risk with combined estrogen-progestin, HT use declined significantly. However, over the past 20 years, much has been learned about the relationship between the timing of HT use with respect to age and time since menopause, HT route of administration, and cardiovascular disease risk. Four leading medical societies recommend HT for the treatment of menopausal women with bothersome menopausal symptoms. In this context, this review, led by the American College of Cardiology Cardiolovascular Disease in Women Committee, along with leading gynecologists, women’s health internists, and endocrinologists, aims to provide guidance on HT use, including the selection of patients and HT formulation with a focus on caring for symptomatic women with cardiovascular disease risk.

The Women's Health Initiative Estrogen-Alone Trial was stopped early after a mean of 7.1 years of follow-up because of an increased risk of stroke and little likelihood of altering the balance of risk to benefit by the planned trial termination date. Postintervention health outcomes have not been reported.To examine health outcomes associated with randomization to treatment with conjugated equine estrogens (CEE) among women with prior hysterectomy after a mean of 10.7 years of follow-up through August 2009.The intervention phase was a double-blind, placebo-controlled, randomized clinical trial of 0.625 mg/d of CEE compared with placebo in 10,739 US postmenopausal women aged 50 to 79 years with prior hysterectomy. Follow-up continued after the planned trial completion date among 7645 surviving participants (78%) who provided written consent.The primary outcomes were coronary heart disease (CHD) and invasive breast cancer. A global index of risks and benefits included these primary outcomes plus stroke, pulmonary embolism, colorectal cancer, hip fracture, and death.The postintervention risk (annualized rate) for CHD among women assigned to CEE was 0.64% compared with 0.67% in the placebo group (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.75-1.25), 0.26% vs 0.34%, respectively, for breast cancer (HR, 0.75; 95% CI, 0.51-1.09), and 1.47% vs 1.48%, respectively, for total mortality (HR, 1.00; 95% CI, 0.84-1.18). The risk of stroke was no longer elevated during the postintervention follow-up period and was 0.36% among women receiving CEE compared with 0.41% in the placebo group (HR, 0.89; 95% CI, 0.64-1.24), the risk of deep vein thrombosis was lower at 0.17% vs 0.27%, respectively (HR, 0.63; 95% CI, 0.41-0.98), and the risk of hip fracture did not differ significantly and was 0.36% vs 0.28%, respectively (HR, 1.27; 95% CI, 0.88-1.82). Over the entire follow-up, lower breast cancer incidence in the CEE group persisted and was 0.27% compared with 0.35% in the placebo group (HR, 0.77; 95% CI, 0.62-0.95). Health outcomes were more favorable for younger compared with older women for CHD (P =.05 for interaction), total myocardial infarction (P =.007 for interaction), colorectal cancer (P =.04 for interaction), total mortality (P =.04 for interaction), and global index of chronic diseases (P =.009 for interaction).Among postmenopausal women with prior hysterectomy followed up for 10.7 years, CEE use for a median of 5.9 years was not associated with an increased or decreased risk of CHD, deep vein thrombosis, stroke, hip fracture, colorectal cancer, or total mortality. A decreased risk of breast cancer persisted.clinicaltrials.gov Identifier: NCT00000611.

In the Women's Health Initiative randomized, placebo-controlled trial of estrogen plus progestin, after a mean intervention time of 5.6 (SD, 1.3) years (range, 3.7-8.6 years) and a mean follow-up of 7.9 (SD, 1.4) years, breast cancer incidence was increased among women who received combined hormone therapy. Breast cancer mortality among participants in the trial has not been previously reported.To determine the effects of therapy with estrogen plus progestin on cumulative breast cancer incidence and mortality after a total mean follow-up of 11.0 (SD, 2.7) years, through August 14, 2009.A total of 16,608 postmenopausal women aged 50 to 79 years with no prior hysterectomy from 40 US clinical centers were randomly assigned to receive combined conjugated equine estrogens, 0.625 mg/d, plus medroxyprogesterone acetate, 2.5 mg/d, or placebo pill. After the original trial completion date (March 31, 2005), reconsent was required for continued follow-up for breast cancer incidence and was obtained from 12,788 (83%) of the surviving participants.Invasive breast cancer incidence and breast cancer mortality.In intention-to-treat analyses including all randomized participants and censoring those not consenting to additional follow-up on March 31, 2005, estrogen plus progestin was associated with more invasive breast cancers compared with placebo (385 cases [0.42% per year] vs 293 cases [0.34% per year]; hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.07-1.46; P =.004). Breast cancers in the estrogen-plus-progestin group were similar in histology and grade to breast cancers in the placebo group but were more likely to be node-positive (81 [23.7%] vs 43 [16.2%], respectively; HR, 1.78; 95% CI, 1.23-2.58; P =.03). There were more deaths directly attributed to breast cancer (25 deaths [0.03% per year] vs 12 deaths [0.01% per year]; HR, 1.96; 95% CI, 1.00-4.04; P =.049) as well as more deaths from all causes occurring after a breast cancer diagnosis (51 deaths [0.05% per year] vs 31 deaths [0.03% per year]; HR, 1.57; 95% CI, 1.01-2.48; P =.045) among women who received estrogen plus progestin compared with women in the placebo group.Estrogen plus progestin was associated with greater breast cancer incidence, and the cancers are more commonly node-positive. Breast cancer mortality also appears to be increased with combined use of estrogen plus progestin.clinicaltrials.gov Identifier: NCT00000611.

Although many physicians have been concerned that the menopausal hormones used currently in clinical practice may affect the risk of breast cancer, there are currently few informative updated studies about the associations between menopausal hormone therapy (MHT) and the risk of breast cancer.

Recent articles have examined the association between the use of combination estrogen‐progestin regimens for hormone replacement therapy (HRT) and the risk of breast cancer. The objective of this Committee Opinion is to evaluate critically the presented evidence. Although epidemiologic studies suggest that the addition of progestins to estrogens may increase the risk of breast cancer, this increased risk has not been proved. The American College of Obstetricians and Gynecologists continues to recommend that HRT be considered as a treatment to relieve vasomotor symptoms and genitourinary tract atrophy and to reduce the risk of osteoporosis and, potentially, cardiovascular disease. Postmenopausal women should be apprised of the current understanding of the risks and benefits of HRT. When considering the use of HRT for longer than 5 years, the clinician and individual patient should weigh the benefits versus the potential side effects and risks for that particular patient.

The 2017 Hormone Therapy Position Statement of The North American Menopause Society (NAMS) updates the 2012 Hormone Therapy Position Statement of The North American Menopause Society and identifies future research needs. An Advisory Panel of clinicians and researchers expert in the field of women's health and menopause was recruited by NAMS to review the 2012 Position Statement, evaluate new literature, assess the evidence, and reach consensus on recommendations, using the level of evidence to identify the strength of recommendations and the quality of the evidence. The Panel's recommendations were reviewed and approved by the NAMS Board of Trustees.Hormone therapy (HT) remains the most effective treatment for vasomotor symptoms (VMS) and the genitourinary syndrome of menopause (GSM) and has been shown to prevent bone loss and fracture. The risks of HT differ depending on type, dose, duration of use, route of administration, timing of initiation, and whether a progestogen is used. Treatment should be individualized to identify the most appropriate HT type, dose, formulation, route of administration, and duration of use, using the best available evidence to maximize benefits and minimize risks, with periodic reevaluation of the benefits and risks of continuing or discontinuing HT.For women aged younger than 60 years or who are within 10 years of menopause onset and have no contraindications, the benefit-risk ratio is most favorable for treatment of bothersome VMS and for those at elevated risk for bone loss or fracture. For women who initiate HT more than 10 or 20 years from menopause onset or are aged 60 years or older, the benefit-risk ratio appears less favorable because of the greater absolute risks of coronary heart disease, stroke, venous thromboembolism, and dementia. Longer durations of therapy should be for documented indications such as persistent VMS or bone loss, with shared decision making and periodic reevaluation. For bothersome GSM symptoms not relieved with over-the-counter therapies and without indications for use of systemic HT, low-dose vaginal estrogen therapy or other therapies are recommended.This NAMS position statement has been endorsed by Academy of Women's Health, American Association of Clinical Endocrinologists, American Association of Nurse Practitioners, American Medical Women's Association, American Society for Reproductive Medicine, Asociación Mexicana para el Estudio del Climaterio, Association of Reproductive Health Professionals, Australasian Menopause Society, Chinese Menopause Society, Colegio Mexicano de Especialistas en Ginecologia y Obstetricia, Czech Menopause and Andropause Society, Dominican Menopause Society, European Menopause and Andropause Society, German Menopause Society, Groupe d'études de la ménopause et du vieillissement Hormonal, HealthyWomen, Indian Menopause Society, International Menopause Society, International Osteoporosis Foundation, International Society for the Study of Women's Sexual Health, Israeli Menopause Society, Japan Society of Menopause and Women's Health, Korean Society of Menopause, Menopause Research Society of Singapore, National Association of Nurse Practitioners in Women's Health, SOBRAC and FEBRASGO, SIGMA Canadian Menopause Society, Società Italiana della Menopausa, Society of Obstetricians and Gynaecologists of Canada, South African Menopause Society, Taiwanese Menopause Society, and the Thai Menopause Society. The American College of Obstetricians and Gynecologists supports the value of this clinical document as an educational tool, June 2017. The British Menopause Society supports this Position Statement.