Pulse Pressure and Cardiovascular Events in Postmenopausal Women With Coronary Heart Disease

Hormone Replacement Therapy and Psoriasis Risk: A Nationwide Population-Based Cohort Study

BACKGROUND

Hormone replacement therapy (HRT) is used to relieve menopause symptoms, but has been reported to be associated with coronary heart disease and cancers in women. However, a link between HRT and psoriasis has yet to be established. The aim of this study was to determine the association between HRT and the risk of psoriasis.

METHODS

We executed a nationwide population-based study. A total of 1,130,741 post-menopause women were enrolled in the national health care insurance database based on the enrollment criteria. The study population was classified into four groups based on the duration of the HRT, and the risk of psoriasis was analyzed.

RESULTS

The incidence rates of psoriasis per 1,000 person-years were 3.36 and 4.09 in the no history of HRT and ≥ 5 years of HRT, respectively. After adjustment for age, smoking, alcohol intake, regular exercise, body mass index, diabetes mellitus, hypertension, and dyslipidemia, the most prolonged duration of the HRT group (≥ 5 years) exhibited significantly increased risk of developing psoriasis (hazard ratio, 1.22; 95% confidence interval, 1.16-1.29).

CONCLUSION

We propose that HRT in post-menopausal women is associated with an increased likelihood of psoriasis development.

Rethinking Menopausal Hormone Therapy: For Whom, What, When, and How Long?

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.

Menopausal hormone therapy in women with medical conditions

Hormone therapy is the most effective treatment for menopause-related symptoms. Current evidence supports its use in young healthy postmenopausal women under the age of 60 years, and within 10 years of menopause, with benefits typically outweighing risks. However, decision making is more complex in the more common clinical scenario of a symptomatic woman with one or more chronic medical conditions that potentially alter the risk-benefit balance of hormone therapy use. In this review, we present the evidence relating to the use of hormone therapy in women with chronic medical conditions such as obesity, hypertension, dyslipidemia, diabetes, venous thromboembolism, and autoimmune diseases. We discuss the differences between oral and transdermal routes of administration of estrogen and the situations when one route might be preferred over another. We also review evidence regarding the effect of different progestogens, when available.

Association of Migraine With Incident Hypertension After Menopause: A Longitudinal Cohort Study

OBJECTIVE

Migraine has been identified as a potential risk factor for hypertension in prospective studies. In women, migraine prevalence decreases after menopause, but no studies have determined whether migraine is associated with hypertension after menopause. This study sought to determine whether history of migraine was associated with an increased risk of hypertension among menopausal women.

METHODS

We assessed associations between migraine and hypertension in a longitudinal cohort study of 56,202 menopausal women participating in the French E3N cohort, with follow-up beginning in 1993. We included women who did not have hypertension or cardiovascular disease at the time of menopause. Migraine was classified as ever or never at each questionnaire cycle. Cox proportional hazards models were used to investigate relations between migraine and hypertension, controlling for potential confounding. A secondary analysis with baseline in 2011 considered aura status, grouping participants reporting migraine as migraine with aura, migraine without aura, or unknown migraine type.

RESULTS

During 826,419 person-years, 12,501 cases of incident hypertension were identified, including 3,100 among women with migraine and 9,401 among women without migraine. Migraine was associated with an increased risk of hypertension in menopausal women (hazard ratio [HR]_migraine 1.29 [95% confidence interval 1.24, 1.35]) and was consistent in post hoc sensitivity analyses, such as when controlling for common migraine medications. Associations between migraine and hypertension were similar whether or not women reported aura (HR_{migraine aura} 1.54 [1.04, 2.30], HR_{migraine no aura} 1.32 [0.87, 2.02], p heterogeneity 0.60). Associations were slightly stronger among ever users of menopausal hormone therapy (HR_migraine 1.34 [1.27, 1.41]) than among never users (HR_migraine 1.19 [1.11, 1.28]).

CONCLUSIONS

Migraine was associated with an increased risk of hypertension among menopausal women. In secondary analysis, we did not observe a significant difference between migraine with aura and migraine without aura.

The hypertensive potential of estrogen: An untold story

Cardiovascular disease (CVD) is the major cause of morbidity and mortality worldwide. The implication of estrogen in this disease has been extensively studied. While the vast majority of published research argue for a cardioprotective role of estrogen in vascular inflammation such as in atherosclerosis, the role of estrogen in hypertension remains far from being resolved. The vasorelaxant effect of estrogen has already been well-established. However, emerging evidence supports a vasoconstrictive potential of this hormone. It has been proposed that the microenvironment dictates the effect of estrogen-induced type 1 nitric oxide synthase-1 (nNOS) on vasotone. Indeed, depending on nNOS product, nitric oxide or superoxide, estrogen can induce vasodilation or vasoconstriction, respectively. In this review, we discuss the evidence supporting the vasorelaxant effects of estrogen, and the molecular players involved. Furthermore, we shed light on recent reports revealing a vasoconstrictive role of estrogen, and speculate on the underlying signaling pathways. In addition, we identify certain factors that can account for the discrepant estrogenic effects. This review emphasizes a yin-yang role of estrogen in regulating blood pressure.

Effects of oral conjugated equine estrogens with or without medroxyprogesterone acetate on incident hypertension in the Women's Health Initiative hormone therapy trials

OBJECTIVE

The aim of the study was to determine the effect of menopausal hormone therapy on incident hypertension in the two Women's Health Initiative hormone therapy trials and in extended postintervention follow-up.

METHODS

A total of 27,347 postmenopausal women aged 50 to 79 years were enrolled at 40 US centers. This analysis includes the subsample of 18,015 women who did not report hypertension at baseline and were not taking antihypertensive medication. Women with an intact uterus received conjugated equine estrogens (CEE; 0.625 mg/d) plus medroxyprogesterone acetate (MPA; 2.5 mg/d) (n = 5,994) or placebo (n = 5,679). Women with prior hysterectomy received CEE alone (0.625 mg/d) (n = 3,108) or placebo (n = 3,234). The intervention lasted a median of 5.6 years in the CEE plus MPA trial and 7.2 years in the CEE-alone trial with 13 years of cumulative follow-up until September 30, 2010. The primary outcome for these analyses was self-report of a new diagnosis of hypertension and/or high blood pressure requiring treatment with medication.

RESULTS

During the CEE and CEE plus MPA intervention phase, the rate of incident hypertension was 18% higher for intervention than for placebo (CEE: hazard ratio [HR], 1.18; 95% CI, 1.09-1.29; CEE plus MPA: HR, 1.18; 95% CI, 1.09-1.27). This effect dissipated postintervention in both trials (CEE: HR, 1.06; 95% CI, 0.94-1.20; CEE plus MPA: HR, 1.02; 95% CI, 0.94-1.10).

CONCLUSIONS

CEE (0.625 mg/d) administered orally, with or without MPA, is associated with an increased risk of hypertension in older postmenopausal women. Whether lower doses, different estrogen formulations, or transdermal route of administration offer lower risks warrant further study.

Chronic exposure to low doses of estradiol-17ß increases blood pressure in young female rats: A possible role for central Endothelin-1

Previously, we demonstrated that chronic exposure to low levels of estradiol-17β (E2) increases mean arterial pressure (MAP) in young female Sprague-Dawley (SD) rats, however, the underlying mechanisms are unclear. Since endothelin-1 (ET-1) is implicated in blood pressure (BP) regulation, we hypothesized that E2’s effects on MAP are mediated through central ET-1. To test this, young female SD rats were either sham implanted or implanted s.c. with slow-release E2 pellets (20 ng/day for 90 days). BP was monitored by telemetry. After 75 days of E2 exposure, ET_A antagonist or vehicle was administered i.c.v. After 90 days of E2 exposure, rats were sacrificed, and the paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) were microdissected for gene expression and protein analysis of ET-1 and its receptors. E2 exposure increased MAP after pellet implantation. Gene expression of ET-1 and ET_A but not ET_B receptors were upregulated in the PVN and RVLM of E2 treated animals. Further, the protein levels of ET_A receptor were also increased in the PVN of E2 treated animals. However, i.c.v. infusion of the ET_A antagonist did not completely block the increase in blood pressure. Our results suggest that increases in central ET-1 activity could possibly play a role in chronic E2-induced increase in BP but further studies are needed to completely understand the contribution of ET-1 in this phenomenon.

Assessing Sex Differences in the Risk of Cardiovascular Disease and Mortality per Increment in Systolic Blood Pressure: A Systematic Review and Meta-Analysis of Follow-Up Studies in the United States

In the United States (US), cardiovascular (CV) disease accounts for nearly 20% of national health care expenses. Since costs are expected to increase with the aging population, informative research is necessary to address the growing burden of CV disease and sex-related differences in diagnosis, treatment, and outcomes. Hypertension is a major risk factor for CV disease and mortality. To evaluate whether there are sex-related differences in the effect of systolic blood pressure (SBP) on the risk of CV disease and mortality, we performed a systematic review and meta-analysis. We conducted a comprehensive search using PubMed and Google Scholar to identify US-based studies published prior to 31 December, 2015. We identified eight publications for CV disease risk, which provided 9 female and 8 male effect size (ES) observations. We also identified twelve publications for CV mortality, which provided 10 female and 18 male ES estimates. Our meta-analysis estimated that the pooled ES for increased risk of CV disease per 10 mmHg increment in SBP was 25% for women (95% Confidence Interval (CI): 1.18, 1.32) and 15% for men (95% CI: 1.11, 1.19). The pooled increase in CV mortality per 10 mm Hg SBP increment was similar for both women and men (Women: 1.16; 95% CI: 1.10, 1.23; Men: 1.17; 95% CI: 1.12, 1.22). After adjusting for age and baseline SBP, the results demonstrated that the risk of CV disease per 10 mm Hg SBP increment for women was 1.1-fold higher than men (P<0.01; 95% CI: 1.04, 1.17). Heterogeneity was moderate but significant. There was no significant sex difference in CV mortality.

Hormone therapy for preventing cardiovascular disease in post-menopausal women

BACKGROUND

Evidence from systematic reviews of observational studies suggests that hormone therapy may have beneficial effects in reducing the incidence of cardiovascular disease events in post-menopausal women, however the results of randomised controlled trials (RCTs) have had mixed results. This is an updated version of a Cochrane review published in 2013.

OBJECTIVES

To assess the effects of hormone therapy for the prevention of cardiovascular disease in post-menopausal women, and whether there are differential effects between use in primary or secondary prevention. Secondary aims were to undertake exploratory analyses to (i) assess the impact of time since menopause that treatment was commenced (≥ 10 years versus < 10 years), and where these data were not available, use age of trial participants at baseline as a proxy (≥ 60 years of age versus < 60 years of age); and (ii) assess the effects of length of time on treatment.

SEARCH METHODS

We searched the following databases on 25 February 2014: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and LILACS. We also searched research and trials registers, and conducted reference checking of relevant studies and related systematic reviews to identify additional studies.

SELECTION CRITERIA

RCTs of women comparing orally administered hormone therapy with placebo or a no treatment control, with a minimum of six months follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for each outcome. We combined results using random effects meta-analyses, and undertook further analyses to assess the effects of treatment as primary or secondary prevention, and whether treatment was commenced more than or less than 10 years after menopause.

MAIN RESULTS

We identified six new trials through this update. Therefore the review includes 19 trials with a total of 40,410 post-menopausal women. On the whole, study quality was good and generally at low risk of bias; the findings are dominated by the three largest trials. We found high quality evidence that hormone therapy in both primary and secondary prevention conferred no protective effects for all-cause mortality, cardiovascular death, non-fatal myocardial infarction, angina, or revascularisation. However, there was an increased risk of stroke in those in the hormone therapy arm for combined primary and secondary prevention (RR 1.24, 95% CI 1.10 to 1.41). Venous thromboembolic events were increased (RR 1.92, 95% CI 1.36 to 2.69), as were pulmonary emboli (RR 1.81, 95% CI 1.32 to 2.48) on hormone therapy relative to placebo.The absolute risk increase for stroke was 6 per 1000 women (number needed to treat for an additional harmful outcome (NNTH) = 165; mean length of follow-up: 4.21 years (range: 2.0 to 7.1)); for venous thromboembolism 8 per 1000 women (NNTH = 118; mean length of follow-up: 5.95 years (range: 1.0 to 7.1)); and for pulmonary embolism 4 per 1000 (NNTH = 242; mean length of follow-up: 3.13 years (range: 1.0 to 7.1)).We performed subgroup analyses according to when treatment was started in relation to the menopause. Those who started hormone therapy less than 10 years after the menopause had lower mortality (RR 0.70, 95% CI 0.52 to 0.95, moderate quality evidence) and coronary heart disease (composite of death from cardiovascular causes and non-fatal myocardial infarction) (RR 0.52, 95% CI 0.29 to 0.96; moderate quality evidence), though they were still at increased risk of venous thromboembolism (RR 1.74, 95% CI 1.11 to 2.73, high quality evidence) compared to placebo or no treatment. There was no strong evidence of effect on risk of stroke in this group. In those who started treatment more than 10 years after the menopause there was high quality evidence that it had little effect on death or coronary heart disease between groups but there was an increased risk of stroke (RR 1.21, 95% CI 1.06 to 1.38, high quality evidence) and venous thromboembolism (RR 1.96, 95% CI 1.37 to 2.80, high quality evidence).

AUTHORS' CONCLUSIONS

Our review findings provide strong evidence that treatment with hormone therapy in post-menopausal women overall, for either primary or secondary prevention of cardiovascular disease events has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events.

Blood pressure, internal carotid artery flow parameters, and age-related white matter hyperintensities

White matter hyperintensities (WMH) are associated with hypertension. We examined interactions among blood pressure (BP), internal carotid artery (ICA) flow velocity parameters, and WMH. We obtained BP measurements from 694 community-dwelling subjects at mean ages 69.6 (±0.8) years and again at 72.6 (±0.7) years, plus brain MRI and ICA ultrasound at age 73±1 years. Diastolic and mean BP decreased and pulse pressure increased, but systolic BP did not change between 70 and 73 years. Multiple linear regression, corrected for vascular disease and risk factors, showed that WMH at the age of 73 years were associated with history of hypertension (β=0.13; P<0.001) and with BP at the age of 70 years (systolic β=0.08, mean β=0.09, diastolic β=0.08; all P<0.05); similar but attenuated associations were seen for BP at the age of 73 years. Lower diastolic BP and higher pulse pressure were associated with higher ICA pulsatility index at the age 73 years (diastolic BP age 70 years: standardized β=-0.24, P<0.001; pulse pressure age 70 years: β=0.19, P<0.001). WMH were associated with higher ICA pulsatility index (β=0.13; P=0.002) after adjusting for BP and correction for multiple testing. Therefore, falling diastolic BP and increased pulse pressure are associated with increased ICA pulsatility index, which in turn is associated with WMH. This suggests that hypertension and WMH may either associate indirectly because hypertension increases arterial stiffness that leads to WMH over time, or coassociate through advancing age and stiffer vessels, or both. Reducing vascular stiffness may reduce WMH progression and should be tested in randomized trials, in addition to testing antihypertensive therapy.

Differential influence of distinct components of increased blood pressure on cardiovascular outcomes: from the atherosclerosis risk in communities study

Elevation in blood pressure (BP) increases risk for all cardiovascular events. Nevertheless, the extent to which different indices of BP elevation may be associated to varying degrees with different cardiovascular outcomes remains unclear. We studied 13340 participants (aged 54 ± 6 years, 56% women and 27% black) of the Atherosclerosis Risk in Communities Study who were free of baseline cardiovascular disease. We used Cox proportional hazards models to compare the relative contributions of systolic BP, diastolic BP, pulse pressure, and mean arterial pressure to risk for coronary heart disease, heart failure, stroke, and all-cause mortality. For each multivariable-adjusted model, the largest area under the receiver-operating curve (AUC) and smallest -2 log-likelihood values were used to identify BP measures with the greatest contribution to risk prediction for each outcome. A total of 2095 coronary heart disease events, 1669 heart failure events, 771 stroke events, and 3016 deaths occurred during 18 ± 5 years of follow-up. In multivariable analyses adjusting for traditional cardiovascular risk factors, the BP measures with the greatest risk contributions were the following: systolic BP for coronary heart disease (AUC=0.74); pulse pressure for heart failure (AUC=0.79); systolic BP for stroke (AUC=0.74); and pulse pressure for all-cause mortality (AUC=0.74). With few exceptions, results were similar in analyses stratified by age, sex, and race. Our data indicate that distinct BP components contribute variably to risk for different cardiovascular outcomes.

Hormone therapy for preventing cardiovascular disease in post-menopausal women

BACKGROUND

Evidence from systematic reviews of observational studies suggest that hormone replacement therapy (HT) may have beneficial effects in reducing the incidence of cardiovascular disease (CVD) events in post-menopausal women. This is an updated version of a Cochrane review first published in 2005 (Gabriel-Sanchez 2005).

OBJECTIVES

To assess the effects of HT for the prevention of CVD in post-menopausal women, and whether there are differential effects between use of single therapy alone compared to combination HT and use in primary or secondary prevention.

SEARCH METHODS

We searched the following databases to April 2010: Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, MEDLINE, EMBASE and LILACS.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of women comparing orally administered HT with placebo with a minimum of six-months follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Risk Ratios (RR) with 95% confidence intervals were calculated for each outcome. Results were combined using fixed-effect meta-analyses, and where possible, further stratified analyses conducted to assess the effect of time on treatment. Additionally, univariate meta-regression analyses were undertaken to assess whether length of trial follow-up, single or combination treatment, or whether treatment for primary or secondary prevention were potential predictors for a number of CVD outcomes in the trials.

MAIN RESULTS

Four new trials were identified through the update; one trial included in the previous review was excluded. Therefore the review included 13 trials with a total of 38,171 post-menopausal women. Overall, single and combination HT in both primary and secondary prevention conferred no protective effects for all cause mortality, CVD death, non-fatal MI, or angina. There were no significant differences in the number of coronary artery by-pass procedures or angioplasties performed between the trial arms. However there was an increased risk of stroke for both primary and secondary prevention when combination and single HT was combined, RR 1.26 (95% CI 1.11 to 1.43), in venous thromboembolic events, RR 1.89 (95% CI 1.58 to 2.26) and in pulmonary embolism RR 1.84 (95% CI 1.42 to 2.37) relative to placebo. The associated numbers needed-to-harm (NNH) were 164, 109 and 243 for stroke, venous thromboembolism and pulmonary embolism respectively.

AUTHORS' CONCLUSIONS

Treatment with HT in post-menopausal women for either primary or secondary prevention of CVD events is not effective, and causes an increase in the risk of stroke, and venous thromboembolic events. HT should therefore only be considered for women seeking relief from menopausal symptoms. Short-term HT treatment should be at the lowest effective dose, and used with caution in women with predisposing risk factors for CVD events.

Hyperintense white matter lesions in 50 high-altitude pilots with neurologic decompression sickness

INTRODUCTION

Neurologic decompression sickness (NDCS) can affect high-altitude pilots, causing variable central nervous system symptoms. Five recent severe episodes prompted further investigation.

METHODS

We report the hyperintense white matter (HWM) lesion imaging findings in 50 U-2 pilot volunteers, and compare 12 U-2 pilots who experienced clinical NDCS to 38 U-2 pilots who did not. The imaging data were collected using a 3T magnetic resonance imaging scanner and high-resolution (1-mm isotropic) three-dimensional fluid-attenuated inversion recovery sequence. Whole-brain and regional lesion volume and number were compared between groups.

RESULTS

The NDCS group had significantly increased whole brain and insular volumes of HWM lesions. The intergroup difference in lesion numbers was not significant.

CONCLUSION

A clinical episode of NDCS was associated with a significant increase in HWM lesion volume, especially in the insula. We postulate this to be due to hypobaric exposure rather than hypoxia since all pilots were maintained on 100% oxygen throughout the flight. Further studies will be necessary to better understand the pathophysiology underlying these lesions.

Effects of oral estradiol and levonorgestrel on cardiovascular risk markers in postmenopausal women

PURPOSE

This study aimed at investigating changes in postmenopausal women's cardiovascular risk markers induced by hormone therapy regimens of low (1.0 mg) or ultra-low (0.5 mg) doses of micronized estradiol (mE(2)) and levonorgestrel (LNG).

METHODS

Three randomized placebo-controlled trials were reanalyzed with regard to changes in cardiovascular risk markers, such as serum lipids, lipoproteins, and coagulation parameters. Trial 1 (n = 210) was an 8-week study comparing the effects of 1.0 or 0.5 mg of unopposed mE(2) on menopausal symptoms. Trial 2 (n = 194) was a 24-week study comparing the effects of 1.0 mg of mE(2) combined with 10, 20, or 40 μg of LNG on endometrial safety. Trial 3 (n = 195) was a 52-week study comparing the effects of 1.0 or 0.5 mg mE(2) + 40 μg LNG on bone metabolism.

RESULTS

1.0 mg of unopposed mE(2) reduced low-density lipoprotein cholesterol (LDL-C) after as little as 8 weeks. 1.0 mg mE(2) for 24 weeks lowered the serum levels of total cholesterol (TC) and LDL-C, whereas the addition of LNG caused decreases in the levels of high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) in a dose-dependent fashion. 1.0 or 0.5 mg mE(2) + 40 μg LNG for 52 weeks also lowered the levels of TC, HDL-C, LDL-C, and TG. Both regimens slightly lowered antithrombin and Protein C activities within normal limits.

CONCLUSIONS

Hormone therapy using 1.0 or 0.5 mg of mE(2) and LNG lowers the serum levels of TC, HDL-C, LDL-C, and TG without significantly affecting coagulation/fibrinolysis parameters.

Chronic estradiol-17β exposure increases superoxide production in the rostral ventrolateral medulla and causes hypertension: reversal by resveratrol

Women are exposed to estrogen in several forms, such as oral contraceptive pills and hormone replacement therapy. Although estrogen was believed to be cardioprotective, lately, its beneficial effects are being questioned. Recent studies indicate that oxidative stress in the rostral ventrolateral medulla (RVLM) may play a role in the development of hypertension. Therefore, we hypothesized that chronic exposure to low levels of estradiol-17β (E(2)) leads to hypertension in adult-cycling female Sprague Dawley (SD) rats potentially through generation of superoxide in the RVLM. To test this hypothesis, young adult (3 or 4 mo old) female SD rats were either sham-implanted or implanted (subcutaneously) with slow-release E(2) pellets (20 ng/day) for 90 days. A group of control and E(2)-treated animals were fed lab chow or chow containing resveratrol (0.84 g/kg of chow), an antioxidant. Rats were implanted with telemeters to continuously monitor blood pressure (BP) and heart rate (HR). At the end of treatment, the RVLM was isolated for measurements of superoxide. E(2) treatment significantly increased mean arterial pressure (mmHg) and HR (beats/min) compared with sham rats (119.6 ± 0.8 vs. 105.1 ± 0.7 mmHg and 371.7 ± 1.5 vs. 354.4 ± 1.3 beats/min, respectively; P < 0.0001). Diastolic and systolic BP were significantly increased in E(2)-treated rats compared with control animals. Superoxide levels in the RVLM increased significantly in the E(2)-treated group (0.833 ± 0.11 nmol/min·mg) compared with control (0.532 ± 0.04 nmol/min·mg; P < 0.05). Treatment with resveratrol reversed the E(2)-induced increases in BP and superoxide levels in the RVLM. In conclusion, these findings support the hypothesis that chronic exposure to low levels of E(2) induces hypertension and increases superoxide levels in the RVLM and that this effect can be reversed by resveratrol treatment.

Whole brain and regional hyperintense white matter volume and blood pressure: overlap of genetic loci produced by bivariate, whole-genome linkage analyses

BACKGROUND AND PURPOSE

The volume of T2-hyperintense white matter (HWM) is an important neuroimaging marker of cerebral integrity with a demonstrated high heritability. Pathophysiology studies have shown that the regional, ependymal, and subcortical HWM lesions are associated with elevated arterial pulse pressure and arterial blood pressure (BP), respectively. We performed bivariate, whole-genome linkage analyses for HWM volumes and BP measurements to identify chromosomal regions that contribute jointly to both traits in a population of healthy Mexican Americans. Our aims were to localize novel quantitative trait loci acting pleiotropically on these phenotypes and to replicate previous genetic findings on whole brain HWM volume and BP measurements.

METHODS

BP measurements and volumes of whole-brain (WB), subcortical, and ependymal HWM lesions, measured from high-resolution (1 mm(3)) 3-dimensional fluid-attenuated inversion recovery images, served as focal quantitative phenotypes. Data were collected from 357 (218 females; mean age=47.9±13.2 years) members of large extended families who participated in the San Antonio Family Heart Study.

RESULTS

Bivariate genomewide linkage analyses localized a significant quantitative trait locus influencing WB and regional (ependymal) HWM volumes and pulse pressure and systolic BP to chromosomal location 1q24 between markers D1S196 and D1S1619. Several other chromosomal regions (1q42, 10q24-q26, and 15q26) exhibited suggestive linkages. The results of the post hoc analyses that excluded 55 subjects taking antihypertensive medication showed no substantive differences from the results obtained in the full cohort.

CONCLUSIONS

This study confirms several previously observed quantitative trait loci influencing BP and cerebral integrity and identifies a novel significant quantitative trait locus at chromosome 1q24. The genetic results strongly support a role for pleiotropically acting genes jointly influencing BP and cerebral white matter integrity.

Decreased lung function is associated with increased arterial stiffness as measured by peripheral pulse pressure: data from NHANES III

BACKGROUND

Individuals with impaired lung function have an elevated risk of cardiovascular events. Improved understanding of the factors associated with increased cardiovascular risk in the setting of lung function impairment is needed. We set out to determine in a nationwide population-based cohort whether impaired lung function as measured by forced expiratory volume in 1 s (FEV1) is associated with evidence of increased arterial stiffness measured by peripheral pulse pressure, a risk factor for cardiovascular events.

METHODS

Cross-sectional study of adults > or = 20 years of age in the Third National Health and Nutrition Examination Survey (NHANES III) who had valid and reproducible FEV1 data and serial blood pressure measurements allowing for the calculation of a mean pulse pressure, a measure of central arterial stiffness (n = 13,090).

RESULTS

There was a significant negative correlation between FEV1 and mean pulse pressure (r = -0.37). After controlling for demographic variables and confounders including cardiovascular risk factors, smoking history, and lung disease, the negative relationship between pulse pressure and FEV1 varies with age and becomes apparent only after age 40. In individuals aged 40-59 and > or = 60 years, there was respectively a 2 and 3 mm Hg increment in pulse pressure for every one standard deviation decrement in FEV1.

CONCLUSIONS

FEV1 is significantly related to pulse pressure, a clinically important measure of arterial stiffness, among those aged > or = 40 years. This relationship may help to explain the increased risk of cardiovascular events found in individuals with impaired lung function.

Comparative effects of conventional vs. novel hormone replacement therapy on blood pressure in postmenopausal women

Menopause is commonly characterized by an increase in blood pressure. Higher blood pressure may partially explain the elevated risk for cardiovascular events observed in postmenopausal women. There is a graded relationship between blood pressure and cardiovascular risk which extends to levels of blood pressure well below 140/90 mmHg, the classical established blood pressure limit for the diagnosis of hypertension. Despite this knowledge and the wide availability of consensus treatment guidelines for hypertension, high blood pressure remains untreated or poorly treated in many postmenopausal patients. It is clear that novel and innovative population strategies for lowering blood pressure in postmenopausal women are warranted. Clinical trials suggest that oral estrogen administration may produce either a neutral effect or a small increase in blood pressure in postmenopausal women. Transdermal estrogen administration has not been studied as extensively but may produce a decrease in blood pressure. The mechanisms for the differences observed between oral and transdermal estrogen have not been completely elucidated. Drospirenone (DRSP) is a novel progestin with aldosterone receptor antagonist activity that has been developed for hormone therapy as DRSP/17beta-estradiol (DRSP/E2). In several clinical trials, DRSP/E2 has demonstrated a significant antihypertensive effect as well an additive effect when combined with existing antihypertensive therapy. Despite the wide availability of treatment guidelines, a wide array of antihypertensive agents, and the introduction of hormone replacement therapy that can lower blood pressure, optimizing blood pressure control remains a serious issue confronting the physician who cares for the postmenopausal woman.

Analysis of genetic variability and whole genome linkage of whole-brain, subcortical, and ependymal hyperintense white matter volume

BACKGROUND AND PURPOSE

The cerebral volume of T2-hyperintense white matter (HWM) is an important neuroimaging marker of cerebral integrity. Pathophysiology studies identified that subcortical and ependymal HWM are produced by 2 different mechanisms but shared a common risk factor: high arterial pulse pressure. Recent studies have demonstrated high heritability of the whole-brain HMW volume and reported significant and suggestive evidence of genetic linkage. We performed heritability and whole-genome linkage analysis to replicate previous reported findings and to study shared genetic variance, and possible overlap for specific loci, between subcortical and ependymal HWM volumes in a population of healthy Mexican Americans.

METHODS

The volumes of subcortical and ependymal HWM regions were measured from high-resolution (1 mm(3)), 3-dimensional fluid-attenuated inversion recovery images acquired for 459 (283 females, 176 males) active participants in the San Antonio Family Heart Study. Subjects ranged in age from 19 to 85 years of age (47.9+/-13.5 years) and were part of 49 families (9.4+/-8.5 individuals per family).

RESULTS

The volumes of whole-brain, subcortical, and ependymal HWM were highly heritable (h(2)=0.72, 0.66, and 0.73, respectively). The subcortical and ependymal HWM volumes shared 21% of genetic variability indicating significant pleiotropy. Genomewide linkage analysis showed only a suggestive bivariate linkage for subcortical and ependymal HWM volumes (log of odds=2.12) on chromosome 1 at 288 cM.

CONCLUSIONS

We replicated previous findings of high heritability for the whole-brain HWM volume. We also showed that subcortical and ependymal volume shared a significant portion of genetic variability and the bivarate linkage analysis produced a suggestive linkage near the locus previously identified in a study of whole-brain HWM volume and arterial pulse pressure.

Association between pulse pressure and 30-month all-cause mortality in peritoneal dialysis patients

BACKGROUND

Pulse pressure (PP) is an independent predictor of cardiovascular and/or all-cause mortality in patients with underlying cardiovascular disease. We examined whether PP can be used to predict overall mortality in peritoneal dialysis (PD) patients.

METHODS

We studied 153 PD patients (mean age, 54.5 +/- 14.2 years) with end-stage renal disease. PP was measured monthly for 3 months. At the time of the third PP measurement, baseline demographic, clinical, biochemical, and dialysis data were collected. Patients were stratified into tertiles according to average PP, and the relationship between blood pressure parameters and all-cause mortality over a 30-month follow-up was assessed using Cox regression.

RESULTS

There were 27 deaths; three deaths occurred after the change to hemodialysis (HD) (subjects died within 3 months after HD) and were counted as events during survival analysis. The overall 30-month survival (Kaplan-Meier curves) times were significantly different among the tertiles of PP (P < 0.05). Increased PP was significantly associated with overall mortality regardless of adjustment for systolic blood pressure (SBP) or diastolic blood pressure (DBP).

CONCLUSIONS

PP may be the most consistent blood pressure indicator of mortality risk. All-cause mortality events in PD patients are more related to pulsatile stress caused by the stiffness of large arteries during systole (reflected in a rise of PP) than to steady-state stress stemming from resistance during diastole (reflected in a rise of SBP and DBP).

Estrogen and hypertension

Menopause is accompanied by a dramatic rise in the prevalence of hypertension in women, suggesting a protective role of endogenous estradiol on blood pressure (BP). Both animal experimental and human clinical investigations suggest that estrogen engages several mechanisms that protect against hypertension, such as activation of the vasodilator pathway mediated by nitric oxide and prostacyclin and inhibition of the vasoconstrictor pathway mediated by the sympathetic nervous system and angiotensin. However, emerging evidence from recent clinical trials indicates a small increase, rather than decrease, in systolic BP with oral estrogen administration in postmenopausal women, without any detectable effect on diastolic BP. Mechanisms underlying this selective rise in systolic BP in postmenopausal women and oral contraceptive-induced hypertension in premenopausal women remain unknown, but the rise may be related to supraphysiologic concentration of estrogen in the liver. To date, transdermal delivery of estrogen, which avoids the first-pass hepatic metabolism of estradiol, appears to have a small BP-lowering effect in postmenopausal women and may be a safer alternative in hypertensive women.

Effects of normal, pre-hypertensive, and hypertensive blood pressure levels on progression of coronary atherosclerosis

OBJECTIVES

The purpose of this study was to evaluate the effects of normal blood pressure (BP), pre-hypertension, and hypertension on progression of coronary atherosclerosis.

BACKGROUND

The Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) classifies BP as normal, pre-hypertension, and hypertension. The effects of these categories on progression of coronary atherosclerosis are unknown.

METHODS

The 274 patients who completed the intravascular ultrasound (IVUS) substudy of the CAMELOT (Comparison of Amlodipine Versus Enalapril to Limit Occurrences of Thrombosis) trial were included. The entry criteria were > or =1 angiographic coronary stenosis >20% and diastolic BP <100 mm Hg. Patients underwent a baseline coronary IVUS, which was repeated after 2 years of amlodipine, enalapril, or placebo therapy. The BP was evaluated periodically, and the averages of the measurements were used in the analyses.

RESULTS

Mean BP throughout the study was 127.0 +/- 12.0/75.5 +/- 6.8 mm Hg. In multivariable analysis, significant determinants of progression included systolic BP (r = 0.16; p = 0.006) and pulse pressure (r = 0.14; p = 0.02). Patients with "hypertensive" average BP had a 12.0 +/- 3.6 mm3 (least-square mean +/- SE) increase in atheroma volume, those with "pre-hypertensive" BP had no major change (0.9 +/- 1.8 mm3), and those with "normal" BP had a decrease of 4.6 +/- 2.6 mm(3) (p < 0.001 by analysis of covariance; p < 0.05 for comparison of all pairs).

CONCLUSIONS

The most favorable rate of progression of coronary atherosclerosis is observed in patients whose BP falls within the "normal" JNC-7 category (i.e., systolic BP <120 mm Hg and diastolic BP <80 mm Hg). This study suggests that in patients with coronary artery disease, the optimal BP goal may be substantially lower than the <140/90 mm Hg level.

The role of pulse pressure in the hemodynamic control of hypertension: exploring the link to cardiovascular remodeling

OBJECTIVE

To correlate the values in the basic blood pressure groups presented in the JNC 7th with the computed values of the Noninvasive Hemodynamic Analyzer (NHA) and to demonstrate the pathophysiological alterations by three proportional hypertensive models.

DESIGN

Hemodynamic values of each of the blood pressure groups presented in the JNC 7th are tabulated for men between 20 and 50 years of age with particular interest in Pulse Pressure.

PATIENTS

Idealized patients were used in the three groups of the proportional hypertensive models.

VALIDITY

Previous studies demonstrated that the Bias, Precision, and Accuracy of Cardiac Output measurement, compared to Thermodilution technique, resulted in statistically acceptable clinical values.

CONCLUSION

This research has successfully demonstrated, with the use of the NHA, the leading role of Pulse Pressure in normal and hypertensive patients. We are convinced that this technique can be used as an economical and time-saving alternative screening tool in clinical medicine.

Age-related cerebral white matter changes and pulse-wave encephalopathy: observations with three-dimensional MRI

Our purpose was to investigate leukoaraïosis (LA) using three-dimensional MR imaging combined with advanced image-processing technology to attempt to group signal abnormalities according to their etiology. Coronal T2-weighted fast fluid-attenuated inversion-recovery (FLAIR) sequences and three-dimensional T1-weighted fast spoiled gradient recalled echo sequences were used to examine cerebral white matter changes in 75 elderly people with memory complaint but no dementia. They were otherwise healthy, community-dwelling subjects. Three subtypes of LA were defined on the basis of their shape, geography and extent: the so-called subependymal/subpial LA, perivascular LA and "bands" along long white matter tracts. Subependymal changes were directly contiguous with ventricular spaces. They showed features of "water hammer" lesions with ventricular systematisation and a more frequent location around the frontal horns than around the bodies (P=.0008). The use of cerebrospinal fluid (CSF) contiguity criterion allowed a classification of splenial changes in the subpial group. Conversely, posterior periventricular lesions in the centrum ovale as well as irregular and extensive periventricular lesions were not directly contiguous with CSF spaces. The so-called perivascular changes showed features of small-vessel-associated disease; they surrounded linear CSF-like signals that followed the direction of perforating vessels. Distribution of these perivascular changes appeared heterogeneous (P ranging from .04 to 5.10(-16)). These findings suggest that subependymal/subpial LA and subcortical LA may be separate manifestations of a single underlying pulse-wave encephalopathy.