Prospective, randomized, controlled study of the effect of hormone replacement therapy on peripheral blood flow velocity in postmenopausal women

Hormone Therapy in Menopause: Concepts, Controversies, and Approach to Treatment

Hormone therapy (HT) is an effective treatment for menopausal symptoms, including vasomotor symptoms and genitourinary syndrome of menopause. Randomized trials also demonstrate positive effects on bone health, and age-stratified analyses indicate more favorable effects on coronary heart disease and all-cause mortality in younger women (close proximity to menopause) than in women more than a decade past menopause. In the absence of contraindications or other major comorbidities, recently menopausal women with moderate or severe symptoms are appropriate candidates for HT. The Women's Health Initiative (WHI) hormone therapy trials-estrogen and progestin trial and the estrogen-alone trial-clarified the benefits and risks of HT, including how the results differed by age. A key lesson from the WHI trials, which was unfortunately lost in the posttrial cacophony, was that the risk:benefit ratio and safety profile of HT differed markedly by clinical characteristics of the participants, especially age, time since menopause, and comorbidity status. In the present review of the WHI and other recent HT trials, we aim to provide readers with an improved understanding of the importance of the timing of HT initiation, type and route of administration, and of patient-specific considerations that should be weighed when prescribing HT.

Hormone therapy is associated with preserved smooth muscle structure and dilation in the arterial vasculature of the leg in older women

Long-term hormone therapy (HT) is associated with reduced intima-medial thickness (IMT), an established risk factor for atherosclerotic disease, in the femoral artery of healthy older women relative to age-matched non-hormone users. However, the influence of continuous, long-term HT on the relation between age, IMT, and smooth muscle dilation has not been investigated in the popliteal artery, an artery prone to stiffening and calcification. In the present study, popliteal artery IMT and smooth muscle dilation (the increase in diameter to sublingual nitroglycerin, NTG) were assessed with Doppler ultrasound in young (Y: n=16; age 23+/-1 [mean+/-S.E.M.]), older non-HT (O non-HT: n=14; age 69+/-1), and older HT (O HT: n=8; age 67+/-1) healthy women. The approximately 0.5 mm increase in resting diameter observed in older non-HT women relative to young women was absent in older HT women, as was the age-related increase in IMT (Y: 0.52+/-0.02 mm; O non-HT: 0.63+/-0.02 mm; O HT: 0.56+/-0.02 mm; p<0.05 for age and hormone comparisons). NTG dilation (percent change above rest) was similarly attenuated in older non-HT women (Y: 8.6+/-1%; O non-HT: 3.0+/-0.7%; O HT: 7.4+/-1.7%; p<0.05 for age and hormone comparisons), and NTG dilation was inversely related to IMT (p<0.01). Collectively, these results suggest that long-term, continuous HT may alleviate the detrimental effects of aging on both structural changes and smooth muscle dilation of the popliteal artery in healthy women.

Effects of estrogen and estrogen-progestogen therapy on homocysteine levels and their correlation with carotid vascular resistance

OBJECTIVE

To evaluate the correlation between homocysteine levels and carotid vascular resistance in menopausal women submitted to estrogen and estrogen-progestogen therapy.

METHODS

Eighty-six women with a mean age of 52 years were enrolled in a prospective, randomized, double-blind, 6-month study. Patients were allocated to use one of three oral therapies: placebo (n = 26), micronized estradiol 2 mg/day (n = 30) or micronized estradiol 2 mg/day plus norethisterone acetate 1 mg/day (n = 30). Evaluation of homocysteine levels and Doppler sonography of the common carotid artery, used to calculate pulsatility index (PI), were carried out prior to initiating therapy and at the end of the study. The correlation between these two parameters was evaluated using Pearson's coefficient of correlation.

RESULTS

There was a significant reduction in homocysteine levels in the groups treated with estrogen alone or estrogen combined with norethisterone. PI was significantly lower only in users of estrogen alone; however, no significant correlation was found between homocysteine measurements and PI.

CONCLUSION

No significant correlation was found between homocysteine levels and carotid vascular resistance following hormone therapy.

Effect of Aerodiol administration on cerebral blood flow volume in postmenopausal women

OBJECTIVE

The aim of the study was to evaluate the acute effect of the intranasal 17beta-estradiol (Aerodiol, Servier, Chambray-les-Tours, France) administration on cerebral blood flow (CBF) volume.

METHODS

Eighteen healthy women who had been natural postmenopausal for at least 1 year were enrolled in the study. We conducted an experimental, randomized, placebo-controlled, crossover, double-blinded study of the acute effect of 17beta-estradiol on the internal carotid artery (ICA), vertebral artery (VA) and, CBF volume using color duplex sonography.

RESULTS

There were significant increases in the ICA, VA flow volumes and CBF volume after 17beta-estradiol administration compared to placebo measurements. However, there was no statistically significant difference in flow velocities or pulsatility indices.

CONCLUSION

Nasal 17beta-estradiol administration in postmenopausal women causes significant increases in CBF volume due to its vasodilatatory effect on ICA and VA.

Carotid and uterine vascular resistance in short-term hormone replacement therapy postmenopausal users

OBJECTIVE

To compare the short-term effects of oral hormone replacement therapy (HRT) and placebo on carotid and uterine vascular impedance.

METHODS

80 postmenopausal women selected from the outpatient clinic of the Hospital Leonor Mendes de Barros in São Paulo, Brazil, were randomized to oral HRT (estradiol 2 mg/norethisterone acetate 1 mg-Kliogest(r)) or placebo. Carotid and uterine arteries pulsatility indices (PIs) were assessed by color Doppler at baseline, after 4 and 12 weeks of treatment. Seventy-six women completed the trial, 38 in each group.

RESULTS

The carotid PI did not decrease significantly in either group. In the uterine arteries, the drop in PI was steeper and greater for HRT women. Drops occurred despite the supposed counteracting effect of norethisterone acetate. In placebo group, there was no significant difference between 4 and 12 weeks of treatment compared with the baseline. The results did not change when analyzed in a real treatment approach.

CONCLUSION

Oral continuous HRT are effective at 12 weeks in reducing impedance to flow in uterine, but not in carotid circulation. These results suggest that the effects of HRT vary by vascular site, and do not have a detectable short-term vascular effect in the carotid area.

Acute efficacy of a sublingual dose of nifedipine on uterine arterial blood flow: preliminary data in prematurely menopausal women

OBJECTIVES

To determine whether the calcium blocker nifedipine alters Doppler velocimetry and impedance parameters in the uterine artery in prematurely menopausal women.

METHODS

Uterine artery Doppler examinations were performed transvaginally in seventeen prematurely menopausal women without the use of calcium blocker (T0). Following a 10-mg sublingual dose of nifedipine patients were subsequently rescanned at successive time intervals (T25 = 25, T40 = 40, T60 = 60 min). PI (normalized (NPI) for heart rate) and maximum, minimum and average velocities of the uterine artery were recorded and waveforms were qualitatively assessed using Goswamy and Steptoe's waveform classification.

RESULTS

Quantitative analysis showed a significant decrease in NPI at T(25) in the right and left uterine arteries (T0: PI = 2.95 and 3.01; T25: PI = 1.52 and 1.52, respectively; P < 0.001) and until the end of the experiment. Minimum and average blood flow velocities increased strongly (P < 0.001) whereas the maximum velocities did not change significantly (P = 0.12). Qualitative analysis revealed more conspicuous results: eight subjects presented 'abnormal' spectra: one was type A (absence of protodiastole), three were type B (absence of telediastole) and four were type O (no diastolic blood flow); all of them recovered type C waveforms (normal spectrum) during the hour following nifedipine administration.

CONCLUSIONS

Nifedipine induces a reversible decrease in NPI and an increase in blood flow velocities in the uterine artery in prematurely menopausal women. These results suggest that nifedipine is a potent uterine arterial vasodilator.

Mortality associated with hormone replacement therapy in younger and older women: a meta-analysis

OBJECTIVE

To assess mortality associated with hormone replacement in younger and older postmenopausal women.

DESIGN

A comprehensive search of MEDLINE, CINAHL, and EMBASE databases was performed to identify randomized controlled trials of hormone replacement therapy from 1966 to September 2002. The search was augmented by scanning selected journals through April 2003 and references of identified articles. Randomized trials of greater than 6 months' duration were included if they compared hormone replacement with placebo or no treatment, and reported at least 1 death.

MEASUREMENTS

Outcomes measured were total deaths and deaths due to cardiovascular disease, cancer, or other causes. Odds ratios (OR) for total and cause-specific mortality were reported separately for trials with mean age of participants less than and greater than 60 years at baseline.

MAIN RESULTS

Pooled data from 30 trials with 26,708 participants showed that the OR for total mortality associated with hormone replacement was 0.98 (95% confidence interval [CI], 0.87 to 1.12). Hormone replacement reduced mortality in the younger age group (OR, 0.61; CI, 0.39 to 0.95), but not in the older age group (OR, 1.03; CI, 0.90 to 1.18). For all ages combined, treatment did not significantly affect the risk for cardiovascular or cancer mortality, but reduced mortality from other causes (OR, 0.67; CI, 0.51 to 0.88).

CONCLUSIONS

Hormone replacement therapy reduced total mortality in trials with mean age of participants under 60 years. No change in mortality was seen in trials with mean age over 60 years.

Influence of hormonal replacement therapy on the regional cerebral blood flow in postmenopausal women

OBJECTIVES

The aim of this study was evaluation of the influence of hormonal replacement therapy (HRT) on the regional cerebral blood flow in postmenopausal women.

METHODS

The study group were 20 postmenopausal women, mean age 48.7 years (S.D. +/- 4.9 years). The control group were ten regularly menstruating women, mean age 32.6 years (S.D. +/- 13.2 years). In the studied group we measured the severity of climacteric syndrome with the use of Kupperman index and serum FSH and 17beta-estradiol level with the use of radioimmunological method. Cerebral blood flow was measured at rest using Single Photon Emission Computed Tomography (SPECT). Tracer accumulation evaluation was performed in three slices defined as: cerebellar slice, thalamic slice and ventricular slice, the reference region was delineated in the cerebellum. In ten women with an impairment in the cerebral blood flow at the beginning of the study all the tests were repeated after 12 months of HRT.

RESULTS

Before HRT mean value of the Kupperman index in the study group was 29.8 points (S.D. +/- 7.1 points); 17beta-estradiol 27 pg/ml (S.D. +/- 2 pg/ml); FSH 56 IU/l (S.D. +/- 49.5 IU/l); SPECT study revealed cerebral blood flow impairment in ten women. In all the studied slices cerebral blood flow was lower in the study group than in the controls. After 12 months of HRT the mean value of the Kupperman index in the study group was 13.2 points (S.D. +/- 2.1 points) (P < 0.05); 17beta-estradiol 44 pg/ml (S.D. +/- 25 pg/ml); FSH 36.4 IU/l (S.D. +/- 57.3 ng/ml); we found cerebral blood flow increase in all studied slices: right cerebellar slice: 5.2%; left cerebellar slice: 4.1%; right thalamic slice: 3.8%; left thalamic slice: 3.3%; right ventricular slice: 7.5%*; left ventricular slice: 6.7%* (* P < 0.05).

CONCLUSIONS

Cerebral blood flow is lower in the postmenopausal women than in regularly menstruating women. HRT increases regional cerebral blood flow and this improvement coexists with an increase of serum 17beta-estradiol level.

Quantification of ovarian stromal Doppler signals in postmenopausal women receiving hormone replacement therapy

OBJECTIVE

To investigate the effect of continuous-combined hormone replacement therapy (HRT) on ovarian circulation, we used three-dimensional power Doppler ultrasound to assess ovarian stromal blood flow in postmenopausal women.

DESIGN

Forty healthy, postmenopausal women were enrolled in this prospective, controlled study. They were divided into two groups: the control group (20 patients with no HRT treatment) and the HRT group [initially 20 patients, but later 15 patients who completed the study, using continuous-combined conjugated equine estrogen (0.625 mg/day) plus medroxyprogesterone (5 mg/day)]. All patients underwent transvaginal three-dimensional power Doppler ultrasonography at the time of recruitment and 3 months later. The ovarian stromal flow indices, including vascularization-flow index (VFI), flow index (FI), and vascularization index (VI), were measured. Blood withdrawals for serum follicle-stimulating hormone and estrogen level testing were obtained before and after 3 months of treatment.

RESULTS

All the variables in the hormone profile showed significant difference (P < 0.05) after 3 months of treatment in the HRT group. Of interest, the three-dimensional power Doppler indices of ovarian stromal flow, VFI (0.13 +/- 0.11 --> 0.59 +/- 0.49), FI (30.47 +/- 12.06 --> 38.41 +/- 10.21), and VI (0.31 +/- 0.27 --> 1.12 +/- 0.95) all showed significant increase (P < 0.05) after 3 months of HRT treatment.

CONCLUSIONS

There was a significant increase in ovarian stromal flow indices after 3 months of treatment in the HRT group, but not in the controls. Monitoring the ovarian flow changes by three-dimensional power Doppler may be of clinical importance when HRT is given.

Quantification of ovarian Doppler signal in hyperresponders during in vitro fertilization treatment using three-dimensional power Doppler ultrasonography

To test the hypothesis that the increased ovarian sensitivity to gonadotropins observed in women embarking on an in vitro fertilization (IVF) treatment may be due to changes in ovarian stromal blood flow, we undertook this prospective comparative clinical study using three-dimensional (3-D) power Doppler ultrasound (US). The 3-D power Doppler ultrasonographic indexes were used to quantify ovarian stromal blood flow and vascularization in hyperresponders. A total of 58 patients undergoing an IVF cycle were recruited and divided into two groups, a hyperresponder group (n = 23) (peak estradiol > 3000 pg/mL or >/= 15 oocytes retrieved) and normal responders (n = 35), based on their response to a standard down-regulation protocol for controlled ovarian stimulation. During ovarian stimulation, on the day of human chorionic gonadotropin (HCG) administration, patients underwent hormonal (serum E2), ovarian volume and 3-D power Doppler (ovarian stroma flow) evaluation. The serum estradiol levels on the day of HCG administration, the number of oocytes retrieved and the ovarian volume were significantly higher in the hyperresponders than in the normal groups. The vascularization flow index (VFI), flow index (FI), and vascularization index (VI), were significantly higher (p < 0.05) in the hyperresponders (1.18 +/- 0.60, 50.23 +/- 2.81 and 2.27 +/- 1.08, respectively), compared to the women with a normal response (0.63 +/- 0.61, 43.19 +/- 7.81 and 1.25 +/- 1.18, respectively). Our study may help to explain the excessive response during gonadotropin administration in the hyperresponsive women.

Hormone replacement therapy with estradiol valerate and cyproterone acetate: effects on endothelium-dependent vasodilatation and arterial wall compliance

OBJECTIVE

to evaluate changes in vasomotor endothelium function and elastic properties of the brachial artery in postmenopausal women beginning hormone replacement therapy (HRT) with Climen(R), a 28-day sequential therapy combining estradiol valerate (E2V) 2 mg/day D1-D21 with cyproterone acetate (CPA) 1 mg/day D12-D22, followed by a 7-day treatment-free interval.

METHODS

Thirty-one women with natural or surgical menopause were included in an open multicenter study. Before treatment, at the end of the estrogen-only phase of cycle 1, and after the combined phase in cycles 1 and 3, endothelium-dependent vasodilatation (EDVD%) in the brachial artery was measured by the post-ischemia increase of the inner diameter, and pulse wave velocity (PWV) was measured in the same artery by simultaneous continuous wave Doppler and photo-plethysmography.

RESULTS

compared to pre-treatment values, the median increase in EDVD was 14.3% after cycle 1 (P=0.0001) and 27.9% after cycle 3 (P=0.0001). CPA did not alter the effect of E2V on EDVD in cycle 1. Median arterial systolic pressure was unchanged, but median diastolic pressure fell from 70 to 67.5 mmHg (P=0.04) after cycle 3. Median PWV was reduced by 0.76 m/s after cycle 3 (relative reduction -9.3%) (P=0.035). There was a significant correlation between PWV and EDVD changes from pre-treatment values at the end of the 3rd cycle.

CONCLUSION

treatment of postmenopausal women with E2V/CPA led to an immediate and significant improvement in endothelium-dependent vasodilatation. The estrogen-related vasomotor effect was not suppressed by the progestogen CPA. The WV changes are consistent with slower improvement of arterial compliance in some women. The non-invasive measurement of EDVD and PWV is a convenient method for the evaluation of both mechanical and functional effects of combination HRT on the arterial wall.

Effects of oophorectomy and hormone replacement therapy on the pulsatility indices of hepatic and renal arteries

OBJECTIVE

To investigate the flow velocity waveform changes of the hepatic and renal arteries in women with surgical menopause who received hormone replacement therapy versus those who did not.

METHODS

Eighty women who had undergone surgical menopause were divided into 2 groups. The first group (n = 38) consisted of patients who did not receive estrogen treatments after surgery; patients in the second group (n = 42) did receive treatments. The hepatic and renal arteries of patients in both groups were examined by duplex Doppler ultrasonography before the commencement of hormone replacement therapy and after 2 years of treatment, and the pulsatility indices were calculated.

RESULTS

No significant differences were detected in the renal and hepatic artery pulsatility indices of patients in the estrogen treatment group (group 2) before and after total abdominal hysterectomy and bilateral salpingo-oophorectomy (P > .05). No significant differences in preoperative and postoperative hepatic arterial pulsatility indices were detected among patients in group 1 (P > .05). Renal artery pulsatility indices measured before and after total abdominal hysterectomy and bilateral salpingooophorectomy did show a statistically significant difference in group 1 (P < .001). In addition, a statistically significant difference was detected before and after surgery in both groups when pulsatility indices were measured at the second-year control dose.

CONCLUSIONS

Hepatic arterial pulsatility indices are not affected in postmenopausal women, but renal artery pulsatility indices rise to some extent in women not receiving hormone replacement therapy.

Ovarian stroma flow intensity decreases by age: a three-dimensional power doppler ultrasonographic study

This was a prospective comparative clinical study to test the hypothesis that the flow intensity of the ovarian stroma decreases in the order of the aging process. A total of 100 consecutive women who came to our outpatient clinic for Pap smear examination were recruited. They were divided into three groups. The premenopause group (58 women) had menstruated within the last 3 months and had normal ovaries (no polycystic ovary or any pathologic cyst or mass), as demonstrated on the baseline ultrasound (US) examination. The perimenopause group (20 women) had last menstruated between 3 and 12 months earlier and had normal ovaries. The postmenopause group (22 women) had had no menstrual cycle within the last 12 months and had normal ovaries. Three-dimensional power Doppler US was applied to quantify the blood flow and vascularization within the stroma of the bilateral ovaries. The results showed that the E2 level decreased in the order of: premenopause (mean +/- SD; 40.88 +/- 40.65 pg/mL), perimenopause (22.00 +/- 13.61 pg/mL), then postmenopause (17.25 +/- 16.40 pg/mL). The vascularization index (VI) (6.95 +/- 8.35; 1.11 +/- 0.93; 0.53 +/- 1.75; respectively), flow index (FI) (15.98 +/- 7.59; 12.00 +/- 3.86; 5.18 +/- 5.31; respectively) and vascularization-flow index (VFI) (1.25 +/- 1.59; 0.18 +/- 0.15; 0.09 +/- 0.32; respectively) all decreased significantly in the order of premenopause, perimenopause, then postmenopause. To the best of our knowledge, this is the first study using 3-D power Doppler sonography that proves that the flow intensity decreases along with the aging process in the ovarian stroma.

Menopause, estrogen, and training effects on exercise hemodynamics: the HERITAGE study

PURPOSE

To investigate the influences of menopause, hormone replacement, and endurance exercise training on cardiovascular hemodynamics and oxygen uptake parameters during exercise in women.

METHODS

Subjects were 338 premenopausal women, 29 postmenopausal women taking hormone replacement, and 28 postmenopausal women not taking hormone replacement, all enrolled in the HERITAGE Family Study. Hemodynamic and oxygen uptake data were gathered on a cycle ergometer at 50 watts (W), 60% peak oxygen uptake, and at peak exercise, both before and after a 20-wk regimen of endurance exercise training on a cycle ergometer.

RESULTS

Systolic blood pressure (SBP) during peak exercise was found to be an average of 14 mm Hg less in postmenopausal women receiving hormones than in those not receiving hormones. Furthermore, menopause was associated with a 26.2 mm Hg higher SBP at 50 W power output, which remained physiologically significant after adjustment for age. At 50 W, postmenopausal women not taking hormones showed a 13.8 mm Hg greater training-induced reduction in SBP than those taking hormones.

CONCLUSION

It was concluded that hormone replacement may be associated with a vasodilatory reserve at high exercise intensities and that endurance exercise training elicits favorable hemodynamic and oxygen uptake adaptations during exercise that are, in most instances, independent of menstrual status or hormone replacement.

Anti-ischemic action of estrogen-progestogen continuous combined hormone replacement therapy in postmenopausal women with established angina pectoris: a randomized, placebo-controlled, double-blind, parallel-group trial

The benefit of treating postmenopausal women with established cardiovascular disease with combined estrogen-progestogen hormone replacement therapy (HRT) is controversial. This study investigated the effect of treatment with estradiol and norethisterone acetate on exercise tolerance and on the frequency and severity of ischemic attacks in postmenopausal women with stable angina pectoris. A total of 74 Chinese women were recruited for this 16-week double-blind, placebo-controlled trial. They were randomly allocated into two groups; one group received placebo/placebo/placebo and the other group received placebo/estrogen-progestogen/placebo. Estrogen-progestogen continuous combined HRT increased both time to 1-mm ST depression (99.1 s, p < 0.05) compared with a mean decrease of 22.9 s with placebo (p < 0.05), and total exercise duration also showed a significant increase (32.7 s, p < 0.05) after treatment compared with placebo (2.5 s, p < 0.05). In addition, the total number of ischemic events/24 h during ambulatory electrocardiographic monitoring decreased by 0.82 events after treatment (p < 0.05) compared with an increase in the placebo group (0.94), a highly significant difference (p = 0.006). These results suggest that the administration of this particular combined hormone replacement preparation may have a beneficial effect on myocardial ischemia in postmenopausal women with established coronary disease.

Effects of androgen supplementation of hormone replacement therapy on the vascular reactivity of cerebral arteries

OBJECTIVE

To determine the effect of the androgen supplementation of hormone replacement therapy (HRT) on the vascular reactivity of cerebral arteries.

DESIGN

Open randomized study.

SETTING

Healthy volunteers in an academic research environment.

PATIENT(S)

Forty postmenopausal women who were treated with sequential HRT (transdermal E2 50 microg/d + medroxyprogesterone acetate 10 mg/d for 12 days every other month) for > or =1 year and < or =5 years.

INTERVENTION(S)

Testosterone undecanoate (40 mg/d, p.o.) was randomly administered to 20 patients during ongoing HRT; the other 20 served as controls. Doppler evaluations of the internal carotid and middle cerebral arteries were performed together with lipid levels assessments. A visual analogue scale (VAS) was used to evaluate various parameters relating to sexual life and well-being.

MAIN OUTCOME MEASURE(S)

Pulsatility index (PI) of the arteries, VAS assessment of psychophysical well-being.

RESULT(S)

The administration of testosterone undecanoate during HRT induced an increase in the PI of the middle cerebral artery and a reduction of high-density lipoprotein cholesterol. Sexual desire and satisfaction were greatly improved.

CONCLUSION(S)

In postmenopausal women, androgen supplementation during HRT can partially counteract the beneficial effects of estrogens on cerebral vascular reactivity and lipid profiles, but sexual desire and satisfaction are greatly improved.

Effects of estrogen therapy on arterial resistance and pulsatility in postmenopausal women

The hypothesis of this study was that changes in arterial determinants of afterload due to static muscular contraction can be modified, in postmenopausal women, by estrogen replacement therapy. Two groups of 14 postmenopausal and 15 premenopausal women were enrolled. Hemodynamic changes induced by right handgrip were recorded between days 7 and 10 of the menstrual cycle in premenopausal women. The same recordings were performed in postmenopausal women, before and after receiving transdermal estrogen replacement therapy for 8 days. Handgrip was performed at 50% of maximal voluntary contraction and maintained until exhaustion. Arterial pressure and blood velocity were recorded in the resting hand with photoplethysmographic and Doppler techniques. Indices of arterial elasticity and resistance were calculated. In postmenopausal women, these indices increased during effort only slightly less after therapy than before, if the mean values and statistical significance were considered, but the most evident effect of therapy was a decrease in interindividual differences in the effort induced changes. This means that, after therapy, increases in arterial resistance and elasticity indices were appreciably prevented mainly in those postmenopausal women who, before therapy, showed the greatest increases. Differences due to therapy were negligible in postmenopausal women in whom, before estrogen replacement, increases in elasticity and resistance indices during effort were similar to those obtained in premenopausal women. After therapy, no differences were found in resting conditions in any of the investigated cardiovascular parameters. Estrogen replacement did not appreciably affect changes in some arterial afterload-related indexes during handgrip, if the average values were considered in a group of postmenopausal women, but uneven and unpredictable peaks in individual responses were cut off, with a better predictability of the responses to sustained muscular contractions, as well as of the related risk factors.

Diurnal variation in uterine artery blood flow in post-menopausal women on oestrogen hormone replacement therapy

Doppler ultrasound was used to investigate circadian variations in uterine artery blood flow in 20 post-menopausal women in the oestrogen-only phase of combined oestrogen hormone replacement therapy with cyclical oral norethisterone or dydrogesterone. All women were examined between 0800 and 0830 h and then again between 1800 and 1830 h on the same day. Mean arterial blood pressure, heart rate and a blood sample for measurement of serum oestradiol were taken at each visit. Indices of uterine artery blood flow included the pulsatility index, resistance index, peak systolic velocity and time-averaged maximum velocity. No significant differences in the mean arterial blood pressure, pulse rate and oestradiol concentrations were detected between morning and evening visits. Significant fluctuation was observed in the pulsatility index (P < 0. 001), resistance index (P < 0.001) and time-averaged maximum velocity (P < 0.01). The assessment of uterine artery blood flow in post-menopausal women should take into account the presence of circadian variations to ensure accuracy and reproducibility of Doppler investigations.