The role of reproductive hormones in vascular disease and hypertension

Steroid Hormones in Cord Blood Mediate the Association Between Maternal Prepregnancy BMI and Birth Weight

OBJECTIVE

Maternal overweight has been associated with increasing offspring birth weight, but epidemiological data on potential biological mechanisms are limited. This study aimed to examine whether steroid hormones mediate the association between maternal prepregnancy BMI (pre-BMI) and birth weight.

METHODS

This study involving 2,039 participants was conducted from an ongoing cohort study in Wuhan, China. Mediation analysis was used to identify the extent to which steroid hormones mediated associations.

RESULTS

Each one-unit increase in pre-BMI was significantly associated with lower log₂ -transformed cord blood levels of cortisol and corticosterone. Levels of cortisol and corticosterone were also negatively associated with birth weight. It was estimated that corticosterone mediated 3.48% of the association between pre-BMI and birth weight, and no significant mediation effect was observed in cortisol. After stratification by maternal gestational weight gain (GWG; within or in excess of the Institute of Medicine [IOM] guidelines), the associations of pre-BMI with cortisol and corticosterone levels were significant in the women with GWG > IOM but not in women with GWG ≤ IOM. When the mediation analysis in the women with GWG > IOM was limited, the mediation effects of cord blood cortisol and corticosterone were both significant (P < 0.05).

CONCLUSIONS

Cord blood cortisol and corticosterone partially mediate the association of increased maternal pre-BMI with higher birth weight.

The expression and activation of sex steroid receptors in the preeclamptic placenta

Estrogen and progesterone are the main pregnancy hormones produced by the placenta. It is well understood that estrogen stimulates angiogenesis in the uterus during the reproductive cycle. Although the estrogen and progesterone signaling pathways are assumed to be associated with placental vascularization and preeclampsia, expression of estrogen receptors (ESRs) and progesterone receptor (PGR) in the placenta have not been well studied. The present study examined the expression patterns of steroid hormone receptors in placentas. Human placenta samples were collected and divided into normal and preeclampsia groups. Results revealed that expression levels of ESR1 were reduced, whereas ESR2 and PGR were elevated in preeclamptic placentas. To generate an in vitro preeclampsia environment, human placenta‑derived BeWo cells were incubated under hypoxic conditions, or treated with catechol‑O‑methyl transferase inhibitor (COMT‑in) or L‑NG‑nitroarginine methyl ester (L‑NAME). Expression levels of ESR1, ESR2 and PGR in hypoxic cells demonstrated similar regulation as those in placentas from women with preeclampsia. Although COMT‑in and L‑NAME did not significantly regulate the expression levels of the receptors, COMT‑in translocated ESR2 and PGR from the nucleus to the cytoplasm, indicating that these receptors were inactivated. These results suggested that ESRs and PGR are associated with symptoms of preeclampsia in the placenta. The expression of ESR1 was reduced in preeclamptic placenta and hypoxic BeWo cells. In addition, the activation of ESR2 and PGR was blocked in placenta cells subjected to COMT‑in treatment. The reduced ESR1 expression and inactivation of ESR2 and PGR proteins may affect the physiological complications of preeclampsia in the placenta.

Aneurysmal Subarachnoid Hemorrhage in Pregnancy-Case Series, Review, and Pooled Data Analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) during pregnancy represents an important cause of maternal and fetal morbidity and mortality. Approaches to diagnostics and treatment are still controversial, and there are only a limited number of cases described in the literature. Our study examines the management of aSAH in pregnant patients, creating a case series by combining patients from our hospital records with those from the limited available literature.

METHODS

Data collected from Addenbrooke's Hospital records and cases published between January 1995 and January 2015 were studied. Chi-square test, exact Fisher's test, and chi-square test for trend were used for analyzing categorical data, while the t-test and Mann-Whitney-Wilcoxon test were used for continuous data.

RESULTS

Fifty-two patients were included. The mean age was 31.47 ± 5.80, and most patients were in their third trimester. A univariate pooled data analysis suggested that the maternal outcome may depend on the mother's age, mother's Hunt and Hess scale score, Glasgow Coma Scale at arrival, treatment modality for the aneurysm, mode, and timing of delivery. However, at the multivariate analysis only the presence of general complications resulted in a significant impact on maternal outcome.

CONCLUSIONS

Ruptured aneurysms in pregnant patients with aSAH may be safely secured in a timely manner. The diagnostic and treatment strategy for each of these patients should consider peculiar maternal and obstetric factors and requires a multidisciplinary assessment involving obstetrics, neurosurgeons, and intensivists. Considering the observed statistical power of our series, our findings should be taken with caution and should be supported by further systematic data collection.

Arterial stiffness and related variables across menopausal status: an epidemiologic study

OBJECTIVES

To determine if postmenopausal women have different arterial stiffness, blood pressure (BP) values, or metabolic patterns in comparison to fertile women and to men at a population level.

METHODS

This is a population-based epidemiologic study of 1853 representative men and women aged 18-95 years. Clinostatic humeral BP was measured using Omron 705CP. Aortic BP, augmentation index (AI), and pulse wave velocity (PWV) were determined using applanation tonometry. Body mass index (BMI) and subscapular skinfold thickness were used as measures of adiposity. Fasting and postload blood glucose, homeostasis model assessment (HOMA), low-density and high-density lipoprotein serum cholesterol (LDL-C and HDL-C) and triglycerides were assessed.

RESULTS

Age was higher in postmenopausal women than in fertile women (68.8 ± 9.5 vs. 35.7 ± 10.2 years, p<0.001), and BMI was 16% higher (p<0.01) in the postmenopausal women after age adjustment. Humeral and aortic BP, carotid and radial AI, carotid-femoral PWV, BMI, LDL-C, LDL-C/HDL ratio, triglycerides, glucose tolerance, HOMA, and skinfold thickness were apparently higher in postmenopausal than in fertile women. Using multivariate analysis, however, all these differences were abolished after adjusting for confounders (age and, when appropriate, BMI), except for LDL-C, which remained 19% higher (p<0.01) in postmenopausal women than in fertile women after adjusting for many confounders (age, BMI, cholesterol, ethanol intake, caloric intake, and triiodothyronine).

CONCLUSIONS

Only LDL-C increases in postmenopausal women, whereas other differences attributed to menopause, including BP and arterial stiffness, seem to be confounding effects of age and BMI.

Association between genetic polymorphisms in androgen receptor gene and the risk of preeclampsia in Korean women

PURPOSE

To investigate associations between the androgen receptor (AR) polymorphisms as CAG repeats, GGC repeats and c.211G>A polymorphism and the risk of preeclampsia.

METHODS

The AR polymorphisms were experienced in 184 preeclamptic patients and 190 normal pregnancies and analyzed by multiple logistic regression.

RESULTS

Women with GGC repeats>16 were more frequently observed in preeclampsia, compared to those with GGC repeats≤16 [adjOR (95% CI): 3.64 (1.71-6.23)]. However, no significant differences were observed between the two groups with respect to CAG repeats. The genotypic and allelic frequencies of c.211G>A variant were significantly higher in cases than in controls (P < 0.05 for both). In the combined distribution of these polymorphisms, the highest risk of preeclampsia was found among women with the haplotype as CAG > 20/GA/GGC >16 [adjOR (95% CI): 4.26 (1.92-12.23)].

CONCLUSIONS

Our findings suggest that longer GGC repeats and c.211G>A variant in the AR gene are associated with increased susceptibility to the risk of preeclampsia.

Progesterone for preventing pre-eclampsia and its complications

BACKGROUND

In the past, progesterone has been advocated for prevention of pre-eclampsia and its complications. Although progestogens are not used for this purpose in current clinical practice, it remains relevant to assess the evidence on their possible benefits and harms.

OBJECTIVES

To assess the effects of progesterone during pregnancy on the risk of developing pre-eclampsia and its complications.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 2), and EMBASE (1974 to August 2005).

SELECTION CRITERIA

Randomised trials evaluating progesterone or any other progestogen during pregnancy for prevention of pre-eclampsia and its complications were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

Two trials of uncertain quality were included (296 women). These trials compared progesterone injections with no progesterone. There was insufficient evidence to demonstrate any clear differences between the two groups on the risk of pre-eclampsia (one trial, 128 women; relative risk (RR) 0.21, 95% confidence interval (CI) 0.03 to 1.77), death of the baby (two trials, 296 women; RR 0.72, 95% CI 0.21 to 2.51), preterm birth (one trial, 168 women; RR 1.10, 95% CI 0.33 to 3.66), small-for-gestational-age babies (one trial, 168 women; RR 0.83, 95% CI 0.19 to 3.57) or major congenital defects (one trial, 168 women; RR 1.65, 95% CI 0.28 to 9.62). There were no reported cases of masculinisation of female babies (one trial, 128 women). Long-term follow up for the children has been reported in one trial, but the data are excluded from the review as 54% were lost to follow up at one year and 80% at 16 years.

AUTHORS' CONCLUSIONS

There is insufficient evidence for reliable conclusions about the effects of progesterone for preventing pre-eclampsia and its complications. Therefore, progesterone should not be used for this purpose in clinical practice at present. Unless new and plausible hypotheses emerge for the role of progesterone in development of pre-eclampsia, further trials of progesterone are unlikely to be a priority.

Castration reduces blood pressure and autonomic venous tone in male spontaneously hypertensive rats

OBJECTIVE

The development of arterial hypertension is sexually dimorphic. Venous tone is elevated in the spontaneously hypertensive rat model of hypertension. This study tested the hypothesis that endogenous androgens exacerbate venous tone in the developmental stages of spontaneous hypertension.

METHODS

Male spontaneously hypertensive rats (SHRs) were subjected to sham operation, castration or castration + testosterone treatment. Ten-week-old SHR rats were instrumented for the measurement of arterial and venous pressure. A balloon catheter was advanced into the right atrium. Mean circulatory filling pressure (MCFP), an index of venous tone, was calculated. Mean arterial pressure (MAP) and MCFP were recorded from conscious rats. Postsynaptic adrenergic responsiveness was assessed by constructing cumulative dose-response curves to norepinephrine (NE). Baseline values and responsiveness to NE were obtained before and after autonomic blockade.

RESULTS

MAP and MCFP were significantly reduced in castrated (MAP, 130 +/- 4 mmHg; MCFP, 5.5 +/- 0.2 mmHg) versus sham-operated SHRs (MAP, 149 +/- 5 mmHg; MCFP, 6.7 +/- 0.3 mmHg) or castrated + testosterone-treated SHRs (MAP, 145 +/- 6 mmHg; MCFP, 7.1 +/- 0.4 mmHg). Ganglion blockade abolished these differences in MAP and MCFP. Infusion of NE caused dose-dependent increases in MAP and MCFP. The MAP responses in castrated SHRs were displaced to the right of those for sham and castrated + testosterone-treated SHRs. This was not evident in the venous circulation, where there were no marked differences in the NE dose-MCFP response curves.

CONCLUSION

Accordingly we conclude that endogenous male sex steroids contribute to the elevated arterial and venous pressures observed in the SHR.

Co-localization of estrogen and angiotensin receptors within subfornical organ neurons

A double-staining immunocytochemical study was done in ovariectomized (OVX) female rats that were either treated with 17beta-estradiol (E(2)) (OVX+E(2)) to produce an approximate circulating level of 30 pg/ml plasma, or not-treated with E(2) (OVX), to investigate the distribution of subfornical organ (SFO) neurons that contained estrogen receptors (ER), and to determine whether these neurons also contained the angiotensin II AT(1)-receptor (AT(1)R). Neurons that contained either ER-like immunoreactivity only, AT(1)R-like immunoreactivity only, or both ER and AT(1)R immunoreactivity were found throughout the extent of the SFO in both the OVX+E(2) and OVX rats. However, some regional differences were apparent in both groups of female rats. Neurons containing the ER were predominantly found in the peripheral regions of the SFO, near large blood vessels and the ependymal layer of the third ventricle. A number of lightly stained ER containing neurons was also observed scattered throughout the central core region of the SFO. OVX only animals were found to have a larger number of ER containing neurons in the SFO compared to the E(2) treated animals. Neurons containing AT(1)R were also found throughout the SFO, but without a distinct distribution pattern in either group of rats, although there were more neurons that exhibited AT(1)R immunoreactivity in the OVX animals. Finally, a distinct group of SFO neurons was found that exhibited both ER and AT(1)R immunoreactivity in both groups of animals, although a larger number of these double labelled neurons was found in the OVX animal. Most of these neurons were also found along the peripheral border of the SFO in close proximity to blood vessels and the ventricular lining. These data have demonstrated the co-existence of ER and AT(1)R in SFO neurons of the female rat, and suggest that circulating level of E(2) alter the expression of both the ER and AT(1)R in these neurons. In addition, these data suggest that E(2) may alter the physiological responses of SFO neurons to angiotensin II by down regulating the number of AT(1)R.

Apolipoproteins and their electrophoretic pattern throughout the reproductive cycle in the green frog Rana esculenta

Lipoprotein fractions in Rana esculenta were separated using the same salt intervals currently applied for human lipoproteins. Very low density lipoproteins (VLDL), low density lipoproteins (LDL) and high density lipoproteins (HDL) were analyzed with reference to the electrophoretic pattern. The lipoprotein electrophoretic pattern in males and females throughout the reproductive cycle showed minor differences. In general, each fraction was characterized by a specific apolipoprotein content. VLDL and LDL fractions were dominated by a high molecular weight (MW) band, most likely the counterpart of human Apolipoprotein B (apo B). The apo B in R. esculenta cross reacted, although weakly, with antibodies raised against chicken apo B. The HDL fraction showed a band with an apparent MW of 29 kDa. The electrophoretic mobility of the protein moiety of HDL was similar to human apolipoprotein A-I (apo A-I). However, HDL apolipoprotein of R. esculenta did not cross react with antibodies against chicken apo A-I under either denaturing or native conditions. The HDL apolipoprotein of R. esculenta was purified by DEAE-Sephacel chromatography followed by HPLC. Its amino acid composition showed a moderate correlation with trout, salmon, chicken and human apo A-I.

Stress reduction and preventing hypertension: preliminary support for a psychoneuroendocrine mechanism

Our objective was to identify endocrine-related mechanisms capable of mediating preventive effects of stress reduction in hypertensive heart disease. Since beneficial effects of stress reduction accrue over time, this cross-sectional, descriptive study sought differences between healthy students not practicing a systematic technique for reducing stress (the average stress, or AS, group, n = 33) and a similar group who for 8.5 years had practiced the Transcendental Meditation (TM) technique, used widely to reduce stress (the low stress, or LS, group, n = 22). The two groups of students, matched for age and area of study, performed timed collections of urine that included (separately) the entire waking and sleeping portions of 1 day. They also completed the Profile of Mood States and the State-Trait Anxiety Inventory, self-report instruments sensitive to subjective level of stress. Urine samples were analyzed for adrenocortical steroids by radioimmunoassay, for Na+, K+, Mg2+, Ca2+, and Zn2+ by atomic absorption spectrometry, and for neurotransmitter metabolites by reverse-phase, high-performance, liquid chromatography, and spectrophotometry. The two groups differed significantly on most measures. Specifically, the LS group was lower in cortisol and aldosterone and higher in dehydroepiandrosterone sulfate (DS) and the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA). Excretion of sodium, calcium, zinc, and the norepinephrine metabolite, vanillylmandelic acid (VMA), was also lower in this group, as were Na+/K+ ratio, mood disturbance, and anxiety. In women practicing TM, cortisol correlated inversely and DS directly with number of months of TM practice. The results identify improvements in mood state, adrenocortical activity, and kidney function as probable factors in the preventive and treatment effects of stress reduction. Because suboptimal levels of these parameters result from chronic, subjective stress, the findings add mechanistic support to the contention that hypertensive heart disease is avoidable, even in modern industrialized societies.

Do gonadotropins influence serum lipoprotein(a) concentrations? Observations on children, adolescents and adults

Data from 7045 subjects were examined. The main groups consisted of the following in- and outpatients: 1414 neonates, 2554 children and adolescents (1336 males, 1218 females), 1209 women directly postpartum, 786 non-pregnant women and 1090 men aged between 18 and 100 years of age. Unless otherwise stated, persons were under medical observation or therapy. The results were obtained over a three-year period using an in-house immunoluminometric assay specific for apolipoprotein(a) using two polyclonal antibodies and single lot of reagents to allow for comparability of results. Girls aged between 10 and 12 years of age had significantly higher serum lipoprotein(a) (median 124 mg/l) levels than boys (median 88 mg/l) of the same age (p < 0.05-Mann-Whitney U-test). Post-pubertal lipoprotein(a) concentrations were not significantly different from pre-pubertal levels. Between the ages of 0-9 and 13-17 years there were no statistically significant sex-linked differences in serum lipoprotein(a). In adults, lipoprotein(a) serum levels were significantly higher in women (median 163 mg/l) aged between 50 and 59 years, when compared with men (median 128 mg/l) of the same age group (p = 0.05-Kruskal-Wallis one way ANOVA followed by the Nemenyi test). There was no significant difference in serum lipoprotein(a) concentrations between healthy women (median 91 mg/l), women direct postpartum (median 116 mg/l) and in-patient women (median 117 mg/l) aged between 18 and 41 years of age (p = 0.11-0.96). There was no correlation between maternal lipoprotein(a) and birth weight in mature newborns (r = -0.028-0.085). The results may indicate a direct influence of gonadotropins at puberty and during the menopause which cause an increase in serum lipoprotein(a) concentrations.

Role of energy balance in athletic menstrual dysfunction

The cessation of menstrual function in the female athlete may reflect her inability to adapt to the environmental and lifestyle stressors associated with training and competition. As society's emphasis on thinness, dieting, and exercise continues to increase, so will the incidence of menstrual dysfunction in active females. Unfortunately, some individuals view athletic menstrual dysfunction as a benign consequence of strenuous exercise. Conversely, it is most likely a strong indicator of overtraining and a marker for future decrements in performance, and it can have long-term health consequences. Thus, it is imperative that the active female be appropriately educated regarding the adverse consequences of menstrual dysfunction and the interventions available. This paper focuses on the most current information regarding athletic menstrual dysfunction and its multifactorial etiology, especially the role of energy drain. In addition, common misconceptions, adverse health and performance effects, and available treatment options are discussed.