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Biomedical subjects

E W Seely

Publications and source records attributed to E W Seely.

At least 19 recordsLinked to original sources

Estradiol increases proteinuria and angiotensin II type 1 receptor in kidneys of rats receiving L-NAME and angiotensin II.

Prospective, placebo-controlled clinical trials suggest that estrogen may have adverse effects on the vascular system in women. The goal of this study was to determine if 17beta-estradiol (E2) would have adverse effects on the renovasculature in a rat model of renal injury characterized by low nitric oxide (NO) and high angiotensin II (AngII). We studied female Wistar rats that were sham-operated (sham), ovariectomized (OVX), or ovariectomized and replaced with E2 (OVX/E2). All rats were maintained on a high salt diet and renovascular injury was caused by treating rats with an inhibitor of NO synthase, N(omega)-nitro-L-arginine-methyl-ester (L-NAME), for 14 days, plus AngII on days 11 through 14. L-NAME/AngII treatment, as compared to placebo, caused proteinuria, glomerular injury, and fibrinoid necrosis of renal arterioles in sham-operated rats. Ovariectomy reduced L-NAME/AngII-induced renal damage, whereas E2 treatment increased L-NAME/AngII-induced damage in OVX rats. In rats treated with L-NAME/AngII, levels of AngII type 1 receptor (AT(1)R) protein were higher in the renal cortex of sham and OVX/E2 rats than in OVX rats. AT(1)R protein correlated with renal injury. E2 treatment also increased expression of AT(1)R mRNA. Thus, under conditions of low NO and high AngII, E2 exacerbated renal injury. E2-mediated increases in renal cortical AT(1)R expression may represent a novel mechanism for the adverse renovascular effects of estrogen.

Angiotensin II↗

Severe hypercholesterolemia mediated by lipoprotein X in patients with chronic graft-versus-host disease of the liver.

We describe a series of cases of extreme hypercholesterolemia mediated by lipoprotein X in patients with chronic graft-versus-host disease of the liver after an allogeneic bone marrow transplant. All of the patients presented with a total cholesterol in excess of 1000 mg/dl (25.9 mmol/l). At the time they were also noted to have pseudohyponatremia. Cholesterol appeared to be predominantly carried by lipoprotein X. Intrahepatic cholestasis leading to reflux of bile lipoproteins into the bloodstream and subsequent formation of protein X appears to be the mechanism underlying this phenomenon. Complications, including retinal cholesterol thromboembolism and cholesteroloma of the lung have been seen in the patient with the highest cholesterol levels. Severe hypercholesterolemia is an important, and likely more common than previously reported, long-term complication of allogeneic hematopoietic stem cell transplantation. It is important for clinicians to familiarize themselves with the diagnostic and therapeutic challenges this condition presents.

Adult↗

Congenital anomaly rate in offspring of mothers with diabetes treated with insulin lispro during pregnancy.

AIM: To determine the rate of major congenital anomalies in offspring of a large group of women with diabetes mellitus treated with insulin lispro (Humalog). METHODS: This multinational, multicentre, retrospective study included mothers with diabetes mellitus (diagnosed prior to conception) who were treated with insulin lispro for at least 1 month before conception and during at least the first trimester of pregnancy. Anomalies were assessed by two independent dysmorphologists not affiliated with the sponsor. RESULTS: The charts of 496 women were reviewed for 533 pregnancies resulting in 542 offspring (500 live births, 31 spontaneous and seven elective abortions, and four stillbirths). Mothers' characteristics: mean (+/- SD) age was 29.9 (+/- 5.2) years, 85.6% were Caucasian and 97.2% had Type 1 diabetes mellitus. Insulin lispro continued to be the main mealtime insulin for more than 96% of the women during the second and third trimester. The dysmorphologists determined that 27 (5.4%) offspring had major congenital anomalies and 2 (0.4%) offspring had minor congenital anomalies. CONCLUSIONS: The rate of major congenital anomalies was 5.4% [95% CI (3.45%, 7.44%)] for offspring of mothers with diabetes mellitus treated with insulin lispro before and during pregnancy. The current published rates of major anomalies in infants born to mothers with diabetes treated with insulin are between 2.1 and 10.9%. This suggests that the anomaly rate with insulin lispro treatment does not differ from the published major congenital anomaly rates for other insulin treatments.

Abnormalities, Drug-Induced↗

Digitalis-like factor response to hyperinsulinemia in human pregnancy, a model of insulin resistance.

Insulin resistance is strongly associated with hypertension and is postulated to participate in the elevation of blood pressure, although the mechanisms involved are not understood. Recently, we reported that acute increases in plasma insulin levels in normal subjects resulted in increased serum levels of a sodium pump inhibitor, termed the digitalis-like factor (DLF), which has been implicated in both experimental and essential human hypertension. This study looked at the DLF response to hyperinsulinemia, achieved by an oral glucose tolerance test (OGTT), in the setting of a naturally occurring and self-resolving state of human insulin resistance, during third-trimester pregnancy. This model allowed us the further opportunity to compare the DLF response to insulin in the same subjects postpartum, after resolution of their insulin resistance. Administration of an OGTT during pregnancy and postpartum in the same subjects elicited a comparable serum glucose response but a significantly greater insulin response during third-trimester pregnancy, consistent with diminished insulin sensitivity (integrated insulin response during pregnancy: 1611+/-236 vs postpartum: 685+/-101 pmol/l, P=0.004). The time courses of the glucose and insulin responses were identical whether women were pregnant or not. Plasma free fatty acids fell significantly and to a comparable degree during pregnancy and postpartum, but the response was slower during pregnancy. DLF levels increased in response to oral glucose in both pregnant and nonpregnant states. The response was more rapid during pregnancy than after. These findings showed that the increment of insulin induced by oral glucose during pregnancy caused a more rapid rise in circulating DLF levels than it did during the nonpregnant state. At the same time, the response of circulating fatty acids to glucose is retarded during pregnancy. This suggests that the insulin resistance of pregnancy impairs insulin's influence on intermediary metabolism but not its influence on DLF. As a vasoactive substance, DLF might contribute to the hypertension characteristic of insulin-resistant states.

Adult↗

Digitalis-like factor response to hyperinsulinemia accompanying a euglycemic hyperinsulinemic clamp or oral glucose tolerance test.

Many studies of essential hypertension find evidence of insulin resistance in the same individuals, leading some to postulate a hypertensive role for insulin. However, the mechanisms by which insulin might exert a hypertensive effect are not fully resolved. An endogenous sodium pump inhibitor or digitalis-like factor (DLF) has been proposed as a hypertensive agent and its plasma concentrations are elevated in hypertension and in Type II diabetes, where insulin levels are elevated. Hence, we studied the effect of insulin on DLF using two approaches to achieve hyperinsulinemia. Normotensive men and women underwent a hyperinsulinemic, euglycemic clamp (40 mU/m2/min insulin, 40 mU = 1.6 x 10(-6) g) in which plasma insulin concentration was kept at high, but physiologic levels. Serum DLF (measured as inhibition of [Na,K]ATPase activity) and insulin levels were measured at baseline and every 30 min throughout the 2 hr clamp. Additionally, other subjects underwent an oral glucose tolerance test (OGTT) as a second means of increasing insulin levels. Insulin and DLF levels were measured prior to and hourly for 3 hours after receiving 100 gm of oral glucose. Serum DLF increased significantly during the clamp from a baseline of 4.6 +/- 0.81 to a peak of 8.7 +/- 1.2% inhibition (p=0.001). Comparison of the baseline and peak DLF levels with concomitant plasma insulin levels revealed a significant correlation (R=0.60, p=0.003). During the OGTT, DLF levels rose from a baseline of 2.4 +/- 1.0 to a peak level of 5.0 +/- 0.4%, p = 0.04. These results suggest that DLF, a factor that can cause vascular smooth muscle contraction and potentially influence blood pressure, is increased by hyperinsulinemia and provides a mechanism by which insulin may increase blood pressure.

Adolescent↗

Relationship of twin zygosity and risk of preeclampsia.

OBJECTIVE: Twin gestations are known to be at higher risk for preeclampsia. One theory suggests that maternal recognition of fetal and trophoblastic tissues as foreign may be a factor. If that hypothesis is true, mothers carrying monozygous (MZ) gestations (ie a single fetal graft) might be predicted to have a lower rate of preeclampsia than those carrying dizygous (DZ) gestations. To evaluate this hypothesis, we compared the rate of preeclampsia in mothers with MZ and DZ twin gestations. STUDY DESIGN: Seven hundred sixty-eight twin deliveries from 1994 to 1999 were reviewed. Placental pathology reports were reviewed to determine the chorionic state of each placenta. Monochorionic placentas were assumed to be MZ. Dichorionic placentas were categorized as DZ if the neonates were of different sexes or different blood types. Maternal and fetal data were abstracted from the medical records. Preeclampsia was defined by standard criteria of the National Institutes of Health Working Group on High Blood Pressure. Our analysis was limited to women with pregnancies reaching at least 30 weeks of gestation where zygosity could be determined. RESULTS: Our analysis included 464 twin pregnancies, 154 MZ and 310 DZ. Among nulliparous women, the rate of preeclampsia was 15% (25/170) for DZ twins versus 20% (15/75) for MZ twins (P =.3). Among multiparous women, the rate was 8% (11/140) for DZ twins and 5% (4/79) for MZ twins (P =.4). In a logistic regression performed to control for confounding by maternal age, gestational age at delivery, assisted reproduction, and male sex, dizygotic state was associated with an odds ratio of 1.4 (95% CI = 0.5-3.9) for developing preeclampsia in nulliparous women and 1.2 in multiparous women (95% CI = 0.3-5.0). CONCLUSIONS: : These results do not support the hypothesis that zygosity affects the rate of preeclampsia in twin gestations, though the number of subjects in our study was too small to allow definitive conclusions. Larger studies are needed to evaluate this finding.

Adult↗

Insulin resistance in hypertensives: effect of salt sensitivity, renin status and sodium intake.

OBJECTIVE: Homeostasis Model Assessment (HOMA index) is predictive of insulin sensitivity in normal and diabetic patients. This study was designed to see if insulin resistance in hypertensives, measured using the HOMA index, differs, based on salt sensitivity, renin status and sodium intake. METHODS: Fasting insulin and glucose were determined in subsets of 426 essential hypertensives, and normotensives. HOMA was calculated as fasting glucose (mmol) x fasting insulin (muU/ml)/22.5. RESULTS: Four hundred and twenty-six essential hypertensives and normotensives from four HERMES centers form the basis of this report. There was no difference in the HOMA index between hypertensives and normotensives (P= 0.291) or between hypertensives grouped according to blood pressure salt sensitivity (P = 0.153). However, when essential hypertensives were subgrouped by renin status, the low-renin group had significantly lower (P< 0.01) HOMA index than the normal/high-renin group. When normal/high-renin group was divided into modulators and non-modulators, the nonmodulators had significantly higher HOMA index (P< 0.001) than other hypertensive subsets. The effect of sodium intake on the HOMA index was significant only for non-modulators (P< 0.002), with salt restriction increasing insulin resistance. CONCLUSION: Insulin sensitivity differs among subsets of essential hypertension, non-modulators being most insulin resistant and the low-renin subset insulin sensitive. Salt restriction might have an adverse effect on insulin sensitivity in non-modulators. The reduction in cardiovascular risk seen in low-renin hypertensives may be related to their increased insulin sensitivity; in contrast, the clustering of cardiovascular risk factors seen in nonmodulators may be due to increased insulin resistance.

Adult↗

Brief review: hypertension in pregnancy : a manifestation of the insulin resistance syndrome?

Pregnancy-induced hypertension (PIH), which includes both gestational hypertension and preeclampsia, is a common and morbid pregnancy complication for which the pathogenesis remains unclear. Emerging evidence suggests that insulin resistance, which has been linked to essential hypertension, may play a role in PIH. Conditions associated with increased insulin resistance, including gestational diabetes, polycystic ovary syndrome, and obesity, may predispose to hypertensive pregnancy. Furthermore, metabolic abnormalities linked to the insulin resistance syndrome are also observed in women with PIH to a greater degree than in normotensive pregnant women: These include glucose intolerance, hyperinsulinemia, hyperlipidemia, and high levels of plasminogen activator inhibitor-1, leptin, and tumor necrosis factor-alpha. These observations suggest the possibility that insulin resistance may be involved in the pathogenesis of PIH and that approaches that improve insulin sensitivity might have benefit in the prevention or treatment of this syndrome, although this requires further study.

Female↗

Body fat distribution and insulin resistance in healthy Asian Indians and Caucasians.

Previous studies have shown that Asian Indians (AIs) are insulin resistant and at high risk for developing diabetes and coronary heart disease, compared with Caucasians. To examine whether differences in body fat distribution contribute to this risk, 12 healthy AIs and 12 Caucasians matched for age and body mass index (BMI) underwent a 75-g oral glucose tolerance test, 2-h euglycemic hyperinsulinemic clamp, abdominal (L2-3) computed tomography scan, and fasting lipid and plasminogen activator inhibitor-1 (PAI-1) levels. Despite similar fasting plasma glucose levels, AIs exhibited fasting hyperinsulinemia (P = 0.001), higher glucose (P = 0.03) and insulin (P = 0.004) levels during the oral glucose tolerance test, and reduced glucose disposal rate (R(d)) (4.7 +/- 0.4 vs. 7.5 +/- 0.3 mg/kg per min, P < 0.0001) during the clamp. AIs had significantly lower high-density lipoprotein, higher low-density lipoprotein, and significantly higher PAI-1 levels (P = 0.01). Despite similar BMI, AIs had significantly greater total abdominal fat (P = 0.04) and visceral fat (P = 0.04). In all subjects, measures of fat mass were inversely correlated with R(d) during the clamp (r = -0.47 to -0.61, P < 0.01-0.001). Visceral fat mass was correlated with triglycerides, low-density lipoprotein, and high-density lipoprotein (P < 0.002-0.0001). PAI-1 was inversely correlated with R(d) in AIs (r = -0.70, P < 0.01) and not in Caucasians (r = -0.24, P = 0.44). For comparable BMI and age, healthy AIs have physiologic markers for insulin resistance, dyslipidemia, and increased cardiovascular risk, compared with Caucasians. Alterations in body fat distribution--particularly increased visceral fat--may contribute to these abnormalities.

Adipose Tissue↗

Differential effects of E and droloxifene on C-reactive protein and other markers of inflammation in healthy postmenopausal women.

Although increased levels of C-reactive protein have been linked to E therapy, the significance of this finding and whether it occurs with the selective ER modulators are unknown. Thirty-five healthy postmenopausal women were enrolled in a placebo-controlled, two-period cross-over design trial to evaluate the effects of 0.625 mg oral conjugated E and 60 mg droloxifene, a structural analog of tamoxifen, on serum levels of C-reactive protein, IL-6, and endothelial cell adhesion molecules. E treatment resulted in 65.8% higher levels of C-reactive protein (P = 0.0002) and 48.1% higher levels of IL-6 (P < 0.001), but also resulted in a 10.9% reduction in soluble E-selectin (P = 0.002) and borderline reductions in vascular cell adhesion molecule-1. In contrast, droloxifene had no effect on C-reactive protein and IL-6, but did produce a significant 11% reduction in E-selectin (P < 0.00001). However, droloxifene also resulted in an 11.6% increase in vascular cell adhesion molecule-1 (P < 0.007). These data provide additional evidence of a proinflammatory effect of E that may have adverse cardiovascular consequences. However, these changes were also accompanied by a reduction in E-selectin, suggesting an antiinflammatory effect at the level of the endothelium. The net clinical impact of these changes is not yet well established. In contrast, droloxifene had little or no proinflammatory effects on C-reactive protein and IL-6 and had mixed effects on endothelial adhesion molecules. This observation provides additional rationale for continuing to evaluate the potential cardiovascular benefits of selective ER modulators.

Acute-Phase Proteins↗

Glucocorticoid-remediable aldosteronism and pregnancy.

Glucocorticoid-remediable aldosteronism (GRA) is a hereditary form of primary hyperaldosteronism that presents with hypokalemia and hypertension from childhood onward. GRA is characterized by the ectopic production of aldosterone in the cortisol-producing zona fasciculata under the regulation of adrenocorticotrophic hormone. Despite the early age of onset, no previous reports of pregnancy and GRA exist. Therefore, we set out to describe the maternal and fetal outcomes of pregnancy in women with GRA. Data regarding the blood pressure and pregnancy outcomes were collected in a retrospective chart review of prenatal and hospital records of 35 pregnancies in 16 women with genetically proven GRA. A total of 6% of pregnancies in women with GRA (GRA+) were complicated by preeclampsia. The published rates of preeclampsia in general obstetric populations vary from 2.5% to 10%. Despite the lack of an apparent increase in the rate of preeclampsia, GRA+ women with chronic hypertension had a high rate (39%) of pregnancy-aggravated hypertension. Starting with a higher baseline blood pressure, maternal blood pressure plotted over the time course of pregnancy followed a quadratic curve similar to that previously described in normal pregnancy. Mean gestational age at delivery was 39.1 weeks. Mean birth weight, excluding the 3 sets of twins, was 3219 g. However, infants of GRA+ mothers with pregnancy-aggravated hypertension tended to have lower birth weights than those that did not (3019 g versus 3385 g, respectively; P=0.08). The primary cesarean section rate was 32%, which is approximately double that seen in other general or hypertensive obstetric populations. In summary, GRA+ women did not seem to have an increased risk of preeclampsia. However, GRA+ women with chronic hypertension seem to be at an increased risk for an exacerbation of their hypertension during pregnancy.

Adult↗

The effect of droloxifene and estrogen on thyroid function in postmenopausal women.

Estrogen is known to increase serum T4-binding globulin (TBG) concentrations, thereby increasing serum total T4 concentrations. Serum free T4 concentrations, however, remain normal. Tamoxifen, a selective estrogen receptor modifier (SERM), also raises serum TBG concentrations, but whether newer SERMs with less stimulatory action on the endometrium do so is not known. We, therefore, compared the effect of droloxifene, a SERM, and conjugated equine estrogen on pituitary-thyroid function in normal postmenopausal women. Ten women were treated for 6 weeks with conjugated estrogen (Premarin), 0.625 mg/day, and droloxifene, 60 mg/day, in a double-blind crossover study with an intervening 4-week no-treatment period. We measured serum T4, T3, TBG, free T4 index, and TSH at baseline and at the end of each 6-week period. The baseline values were compared with the 6-week values using paired t tests. The mean (+/- SD) serum TBG concentrations increased significantly during both treatment periods (baseline, 1.5+/-0.4 mg/dL; conjugated estrogens, 2.7+/-0.6 mg/dL; droloxifene, 2.1+/-0.6 mg/dL; P < 0.001 and P = 0.001, respectively). There were no significant changes in the serum free T4 index. Serum T4 and T3 concentrations increased during both treatment periods, however, the increase was significant only for T4 during the conjugated estrogen treatment period. The serum TSH concentrations increased significantly during both treatment periods (18% during conjugated estrogen and 11% during droloxifene), and the values remained within the normal range in all women. Administration of both conjugated estrogen and droloxifene for 6 weeks increases serum TSH and TBG concentrations, but does not alter free T4 index values in postmenopausal women.

Aged↗

Higher cholesterol and insulin levels in pregnancy are associated with increased risk for pregnancy-induced hypertension.

Hyperinsulinemia and dyslipidemia are known to be associated with essential hypertension but their role in pregnancy-induced hypertension remains unclear. We performed a case-control study comparing cholesterol, insulin, and glucose levels in the early third trimester of pregnancy among 31 women who developed pregnancy-induced hypertension (PIH) (either preeclampsia [n = 6] or nonproteinuric gestational hypertension [n = 25]), with 31 women remaining normotensive through pregnancy. As compared with women remaining normotensive, women subsequently developing PIH had higher fasting cholesterol levels (279 v 247 mg/dL; P = .02) and higher fasting insulin levels (13.3 v 7.9 microU/mL; P = .03), although fasting glucose levels and levels of glucose and insulin after glucose load did not differ significantly between groups. In comparing hypertensive subgroups, fasting insulin levels were significantly higher among women who subsequently developed preeclampsia, but not among those subsequently developing nonproteinuric gestational hypertension. Although women developing PIH had higher pregravid body mass index (25.1 v 22.6 kg/m2, P = .06), fasting cholesterol and insulin levels were associated with risk for PIH even after adjustment for body mass index and age (relative risks for one unit increase, respectively: 1.02 (P = .03) and 1.12 (P = .03). Higher fasting cholesterol and insulin levels in mid- to late pregnancy are associated with increased risk for PIH. These observations support a role for insulin resistance in the development of this complication of pregnancy.

Case-Control Studies↗

Eclampsia: a 13-year experience at a United States tertiary care center.

Eclampsia, the occurrence of a grand mal seizure in the setting of hypertension in pregnancy, remains a major women's health issue and an important cause of maternal and fetal morbidity in the United States. We reviewed the incidence, management, and outcome of cases of eclampsia during a 13-year period at a major maternity hospital. We confirmed 33 cases of eclampsia seen during that period and have evaluated risk factors in this population. Medical records were reviewed to obtain demographic and clinical data. Characteristics of the eclamptic women were compared with those of the general obstetric population during the same time period. The overall incidence of eclampsia at this tertiary care center was 0.028%. The majority of eclamptic women (75%) had four or more prenatal visits. Young age (< or = 20 years) and first pregnancy remained important risk factors for eclampsia. Although many women with eclampsia had preceding hypertension or elevated urine protein levels or both, some experienced eclampsia as their first disease manifestation. Although the occurrence of eclampsia was low, eclampsia continues to complicate pregnancy in this large U.S. obstetric population.

Adult↗

Resolution of fetal goiter after discontinuation of propylthiouracil in a pregnant woman with Graves' hyperthyroidism.

We report a case of Graves' hyperthyroidism in a 34-year-old pregnant woman treated with propylthiouracil (PTU) complicated by the development of a fetal goiter. Because of the fetal goiter and normal maternal thyroid function tests, the PTU was discontinued. Over the next 10 weeks, there was a progressive decrease in the fetal thyroid volume as documented by ultrasonography. The fetal neck returned to a normal flexed position, fetal growth and amniotic fluid remained normal, and the patient remained asymptomatic. A normal infant was delivered at term. This is the first report to demonstrate that noninvasive management may be appropriate for fetuses with goiter caused by antithyroid drug therapy.

Adult↗

Estradiol with or without progesterone and ambulatory blood pressure in postmenopausal women.

The purpose of this study was to determine whether transdermal estradiol and intravaginal progesterone given in doses to mimic the premenopausal state would lower blood pressure (BP) in postmenopausal women. Fifteen healthy postmenopausal women were studied in each of 3 conditions: on placebo, after 8 weeks of transdermal estradiol 0.2 mg twice per week, and again 2 weeks after addition of intravaginal progesterone 300 mg/d. Women were studied at each point after 2 days of 100 mmol/d sodium intake. Twenty-four-hour ambulatory BP monitoring was performed, and blood was assayed for estradiol, progesterone, and hormones of the renin-angiotensin-aldosterone system (RAAS). ANOVA with pairwise comparisons was used for analysis. Urinary sodium excretion was similar at each time point. Levels of estrogen and progesterone similar to those in premenopausal women were achieved. On estradiol, nocturnal systolic BP (110+/-3 mm Hg), diastolic BP (63+/-2 mm Hg), and mean BP (77+/-2 mm Hg) fell significantly (P<0.02) compared with placebo systolic BP (116+/-2 mm Hg), diastolic BP (68+/-2 mm Hg), and mean BP (82+/-2 mm Hg). Daytime BP followed the same trend but was significantly lower only for mean BP. There was no activation of the RAAS. The addition of progesterone resulted in no further fall in BP but a significant activation of the RAAS. Thus, contrary to what is often assumed, administration of estradiol with or without progesterone not only did not raise BP but rather substantially lowered BP. This BP-lowering effect may be responsible for the lower incidence of hypertension in premenopausal than in postmenopausal women.

Administration, Cutaneous↗

Estradiol therapy combined with progesterone and endothelium-dependent vasodilation in postmenopausal women.

BACKGROUND: Epidemiological studies indicate that estrogen replacement therapy decreases the risk of cardiovascular events in postmenopausal women. Estrogen may confer cardiovascular protection by improving endothelial function because it increases endothelium-dependent vasodilation. It is not known whether progesterone attenuates the beneficial effects of estrogen on endothelial function. METHODS AND RESULTS: Seventeen postmenopausal women with mild hypercholesterolemia were enrolled in a placebo-controlled, crossover trial to evaluate the effect of transdermal estradiol, with and without vaginal micronized progesterone, on endothelium-dependent vasodilation in a peripheral conduit artery. Brachial artery diameter was measured with high-resolution B-mode ultrasonography. To assess endothelium-dependent vasodilation, brachial artery diameter was determined at baseline and after a flow stimulus induced by reactive hyperemia. To assess endothelium-independent vasodilation, brachial artery diameter was measured after administration of sublingual nitroglycerin. During estradiol therapy, reactive hyperemia caused an 11.1+/-1.0% change in brachial artery diameter compared with 4. 7+/-0.6% during placebo therapy (P<0.001). Progesterone did not significantly attenuate this improvement. During combined estrogen and progesterone therapy, flow-mediated vasodilation of the brachial artery was 9.6+/-0.8% (P=NS versus estradiol alone). Endothelium-independent vasodilation was not altered by estradiol therapy, either with or without progesterone, compared with placebo. There was a modest decrease in total and LDL cholesterol during treatment both with estradiol alone and when estradiol was combined with progesterone (all P<0.001 versus placebo). In a multivariate analysis that included serum estradiol, progesterone, total and LDL cholesterol concentrations, blood pressure, and heart rate, only the estradiol level was a significant predictor of endothelium-dependent vasodilation. CONCLUSIONS: The addition of micronized progesterone does not attenuate the favorable effect of estradiol on endothelium-dependent vasodilation. The vasoprotective effect of hormone replacement therapy may extend beyond its beneficial actions on lipids.

Aged↗