High Blood Pressure and Cardiovascular Disease

Fragmented investigation has masked the overall picture for causes of cardiovascular disease (CVD). Among the risk factors for CVD, high blood pressure (BP) is associated with the strongest evidence for causation and it has a high prevalence of exposure. Biologically, normal levels of BP are considerably lower than what has typically been characterized as normal in research and clinical practice. We propose that CVD is primarily caused by a right-sided shift in the population distribution of BP. Our view that BP is the predominant risk factor for CVD is based on conceptual postulates that have been tested in observational investigations and clinical trials. Large cohort studies have demonstrated that high BP is an important risk factor for heart failure, atrial fibrillation, chronic kidney disease, heart valve diseases, aortic syndromes, and dementia, in addition to coronary heart disease and stroke. In multivariate modeling, the presumed attributable risk of high BP for stroke and coronary heart disease has increased steadily with progressive use of lower values for normal BP. Meta-analysis of BP-lowering randomized controlled trials has demonstrated a benefit which is almost identical to that predicted from BP risk relationships in cohort studies. Prevention of age-related increases in BP would, in large part, reduce the vascular consequences usually attributed to aging, and together with intensive treatment of established hypertension would eliminate a large proportion of the population burden of BP-related CVD.

Oxytocin receptors in the human uterus during pregnancy and parturition

We have determined the concentration and distribution of oxytocin receptors in myometrial and decidual tissues obtained at cesarean section or hysterectomy during pregnancy. Myometrial receptor concentration was low at 13 to 17 weeks but had risen about twelvefold by 37 to 41 weeks. After the onset of labor, either preterm or term, the receptor levels were maximal and significantly higher than before the onset of labor. In cases of failed induction of labor with oxytocin and in postterm pregnancies (43 to 46 weeks), the receptor concentration was significantly lower than in spontaneous labor. Myometrial receptor concentrations in the fundus and the corpus were similar and significantly higher than in the lower part of the uterine segment, and the cervix had the lowest concentration. The parietal decidua had oxytocin receptor concentrations of the same magnitude as the myometrium. These results are consistent with a functional role of endogenous oxytocin in the activation of the human uterus during pregnancy and parturition.

Oxytocin receptors and human parturition: a dual role for oxytocin in the initiation of labor

The concentration of oxytocin receptors increased in the myometrium of pregnant women and reached maximum levels in early labor. Concentrations of oxytocin receptors were also high in the decidua and reached a maximum at parturition. In vitro, prostaglandin production by the decidua, but not by the myometrium, was increased by the addition of oxytocin. Oxytocin may therefore stimulate uterine contractions by acting both directly on the myometrium and indirectly on decidual prostaglandin production. Oxytocin receptors are probably crucial for the onset of human labor, and the stimulus for the increase in uterine prostaglandins may be oxytocin originating from the fetus.

Alcohol consumption and the incidence of hypertension: The Atherosclerosis Risk in Communities Study

A close relationship between alcohol consumption and hypertension has been established, but it is unclear whether there is a threshold level for this association. In addition, it has infrequently been studied in longitudinal studies and in black people. In a cohort study, 8334 of the Atherosclerosis Risk in Communities (ARIC) Study participants, aged 45 to 64 years at baseline, who were free of hypertension and coronary heart disease had their blood pressures ascertained after 6 years of follow-up. Alcohol consumption was assessed by dietary interview. The type of alcoholic beverage predominantly consumed was defined by the source of the largest amount of ethanol consumed. Incident hypertension was defined as a systolic blood pressure >/=140 mm Hg or diastolic blood pressure >/=90 mm Hg or use of antihypertensive medication. There was an increased risk of hypertension in those who consumed large amounts of ethanol (>/=210 g per week) compared with those who did not consume alcohol over the 6 years of follow-up. The adjusted odds ratios (95% confidence interval) were 1.2 (0.85 to 1.67) for white men, 2.02 (1.08 to 3.79) for white women, and 2.31 (1.11 to 4.86) for black men. Only 4 black women reported drinking >210 g ethanol per week. At low to moderate levels of alcohol consumption (1 to 209 g per week), the adjusted odds ratios (95% confidence interval) were 0.88 (0.71 to 1.08) in white men, 0.89 (0.73 to 1.09) in white women, 1.71 (1.11 to 2.64) in black men, and 0.88 (0.59 to 1.33) in black women. Systolic and diastolic blood pressures were higher in black men who consumed low to moderate amounts of alcohol compared with the nonconsumers but not in the 3 other race-gender strata. Models with polynomial terms of alcohol exposure suggested a nonlinear association in white and black men. Higher levels of consumption of all types of alcoholic beverages were associated with a higher risk of hypertension for all race-gender strata. The consumption of alcohol in amounts >/=210 g per week is an independent risk factor for hypertension in free-living North American populations. The consumption of low to moderate amounts of alcohol also appears to be associated with a higher risk of hypertension in black men.

Sleep duration and mortality in the elderly: a systematic review with meta-analysis

OBJECTIVE

The purpose of our study was to evaluate the association between short and long sleep duration and all-cause and cardiovascular mortality among elderly individuals.

DESIGN

Systematic review and meta-analysis of population-based cohort studies.

SETTING

Articles were retrieved from international and national electronic databases.

STUDY SELECTION

Studies were identified in PubMed, EMBASE, LILACS (Latin American and Caribbean Health Sciences Literature), IBECS (Bibliographic Index on Health Sciences from Spain) and CAPES (PhD thesis repository) between 1980 and 2015. Studies which met all criteria were eligible: participants aged 60 years or over, assessment of sleep duration as 24 h, nighttime or daytime sleep, evaluation of all-cause or cause-specific mortality, population-based cohort studies conducted on representative samples. There was no language restriction and studies published as abstracts were excluded.

DATA EXTRACTION

Data were analysed using the Comprehensive Meta-Analysis software (V.3.3.070), and summary estimates (relative risk (RR), 95% CI) were calculated using a random effects model. Heterogeneity and consistency were evaluated through Cochran's Q and the I(2) statistics, respectively, and sensitivity analyses were conducted.

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause and cardiovascular mortality.

RESULTS

Overall, 27 cohort studies were selected, comprising >70,000 elderly individuals, and followed up from 3.4 to 35 years. In the pooled analysis, long and short sleep duration were associated with increased all-cause mortality (RR 1.33; 95% CI 1.24 to 1.43 and RR 1.07; 95% CI 1.03 to 1.11, respectively), compared with the reference category. For cardiovascular mortality, the pooled relative risks were 1.43 (95% CI 1.15 to 1.78) for long sleep, and 1.18 (95% CI 0.76 to 1.84) for short sleep. Daytime napping ≥ 30 min was associated with risk of all-cause mortality (RR 1.27; 95% CI 1.08 to 1.49), compared with no daytime sleep, but longer sleep duration (≥ 2.0 h) was not (RR 1.34; 95% CI 1.95 to 1.90).

CONCLUSIONS

Among elderly individuals, long and short sleep duration are associated with increased risk for all-cause mortality. Long sleep duration is associated with cardiovascular mortality.

Does psychosocial stress cause hypertension? A systematic review of observational studies

Acute stress promotes transient elevation of blood pressure, but there is no consistent evidence that this effect results in hypertension. In this systematic review of cohort and case-control studies that investigated the association between psychosocial stress and hypertension, we conducted a complete search up to February 2007 in MEDLINE, EMBASE, PSYCINFO and LILACS, through a search strategy that included eight terms to describe the exposure, six related to the design of the studies and one term for outcome. The quality was assessed by the Newcastle-Ottawa Quality Assessment Scale. The selection was done in duplicate by two teams of independent reviewers. Among 82 studies selected in the second phase, only 14 (10 cohort studies and 4 case-control studies), totalling 52,049 individuals, fulfilled the selection criteria. The average quality of the studies was 6.6+/-1.3 in a 9-point scale. Acute life events were associated with hypertension in one and were not associated in two studies. Five out of seven studies found a significant and positive association between measures of chronic stress and hypertension, with risk ratios ranging from 0.8 to 11.1. Three out of five studies reported high and significant risks of affective response to stress for hypertension, one a significant risk close to a unit and one reported absence of risk. Acute stress is probably not a risk factor for hypertension. Chronic stress and particularly the non-adaptive response to stress are more likely causes of sustained elevation of blood pressure. Studies with better quality are warranted.

A series of 238 cytomegalovirus primary infections during pregnancy: description and outcome

OBJECTIVE

To analyze the outcome of maternal primary cytomegalovirus (CMV) infection.

METHODS

Retrospective analysis of a cohort of 238 patients with maternal primary CMV infection detected at routine screening. The cases were managed with serial ultrasound (US) scans, and amniocentesis was performed in 36.1% of cases. All prenatal results were confirmed at birth.

RESULTS

The average age was 31.9 (18-44) years. Patients were symptomatic in 21% of cases. The rate of intrauterine transmission was 24.9%, and it was 8.8%, 19%, 30.6%, 34.1% and 40% in the preconceptional period, the periconceptional period, and the first, second and third trimesters of pregnancy, respectively (p = 0.025). There was a significantly higher risk of US abnormalities when maternal infection occurred during the preconceptional or periconceptional period and the first trimester compared with later (p < 0.001). Because of US abnormalities, pregnancy was terminated in 18 cases at the parents' request. Three infected newborns were symptomatic; all three cases were suspected at US before birth. We did not observe any symptomatic fetal infection when maternal infection occurred after 14 weeks of gestation. A number of clinically asymptomatic cases (5.5%) developed hearing loss.

CONCLUSION

The rate of materno fetal transmission is linearly correlated to the gestational age at infection. No severe case of congenital infection was observed if maternal infection occurred after 14 weeks of gestation.

Length, force, and Ca(2+)-troponin C affinity in cardiac and slow skeletal muscle

Troponin C occurs as two isoforms, one (sTnC) expressed in fast skeletal muscle and the other (cTnC) expressed in cardiac and slow skeletal muscle. On the basis of subunit exchange experiments it has been suggested that cTnC may play a specific role as a length-sensing molecule. In this study we have compared skinned fibers from bovine ventricle and slow rabbit soleus muscle with respect to the effects of force and sarcomere length on Ca2+ binding to troponin C. A double-isotope technique was used to measure Ca2+ binding concurrent with force generation. The phosphate analogue vanadate was used to regulate force independent of free Ca2+ concentration. To determine the effect of sarcomere length, muscle fibers were released from longer sarcomere length to shorter sarcomere length, and bound Ca2+ was determined either before or after the release. Reduction in force or length was associated with reduced binding of Ca2+ to cTnC in cardiac muscle, but no effect of these interventions was seen in soleus muscle. Thus the nature of the mechanical feedback on the regulatory Ca(2+)-binding sites appears to be a property of the myofilament system rather than the troponin C isoform.

Endocrinology of human parturition: a review

The existing data on the hormonal factors involved in human parturition indicate that the steroid hormones, progesterone and the oestrogens, play only a facilitatory role in the initiation of labour. A definite role for fetal adrenal steroids in this process has yet to be established, and they too may serve only a facilitating function. The stimulation of the uterine muscle during labour results from an interaction of oxytocin and prostaglandin (PG) F2 alpha. Recent evidence suggests that oxytocin is most important for the initial phase of labour, whereas increased synthesis of PGF2 alpha is essential for the progression of labour. The role of PGE2 remains unclear, but this PG may play an important role in the ripening of the cervix which in turn is essential for successful parturition. The finding of maximal oxytocin receptor concentrations in the myometrium in labour adds strong support to the notion that oxytocin is the trigger for uterine contractions. The factors which control oxytocin receptor formation are therefore important; this may be one of the processes where the steroids play a crucial role. Oxytocin is also one of the stimuli that increase uterine PG synthesis; the coupling of oxytocin receptor occupancy and PG synthetase activity in uterine tissues may be another crucial factor in the mechanism of labour. The formation of gap junctions between the myometrial cells also seems essential for the synchronization and progression of myometrial activity. We propose, therefore, that the co-ordinating of oxytocin receptor formation, PG synthesis and gap junction formation is a key to the initiation and maintenance of human labour. The fetus may fulfil such a co-ordinating role through its influence on placental oestrogen production, through mechanical distention of the uterus, and through its secretion of neuro-hypophysial hormones and other stimulators of PG synthesis.

Effect of length and cross-bridge attachment on Ca2+ binding to cardiac troponin C

The sensitivity of skinned cardiac muscle bundles to Ca2+ is a function of sarcomere length. Ca2+ sensitivity is increased as fiber length is extended along the ascending limb of the force-length curve and it has been suggested that this phenomenon makes a major contribution to the steep force-length relationship that exists in living cardiac muscle. To gain greater insight into the mechanism behind the length dependence of Ca2+ sensitivity isotopic measurements of Ca2+ binding to detergent-extracted bovine, ventricular muscle bundles were made under conditions in which troponin C was the only major Ca2+ binding species. Experiments were designed to determine whether 1) Ca2+-troponin C affinity varies in the sarcomere length range corresponding to the ascending limb of the force-length curve, and 2) Ca2+ binding correlates with length per se or with changes in the number of length-dependent cross-bridge attachments. Measurements were made of Ca2+ binding in the rigor and relaxed states. The latter state was produced by suppressing actin-myosin interaction with the phosphate analogue, sodium vanadate. After vanadate treatment it is possible to obtain a complete Ca2+ saturation curve in the presence of physiological MgATP concentrations and at constant sarcomere length. The results show that the binding of Ca2+ to the regulatory site of cardiac troponin C is length dependent but this length dependence is actually a dependence on the number of attached cross bridges.

Trends in prevalence of hypertension in Brazil: a systematic review with meta-analysis

Background

The prevalence of hypertension in emerging nations was scarcely described to date. In Brazil, many population-based surveys evaluated the prevalence in cities throughout the country. However, there is no population-based nationwide study of prevalence of hypertension. In this study, we estimated the prevalence of hypertension for the country and analyzed the trends for the last three decades.

Methods

Cross-sectional and cohort studies conducted from 1980 to 2010 were independently identified by two reviewers, without language restriction, in the PubMed, Embase, LILACS, and Scielo electronic databases. Unpublished studies were identified in the Brazilian electronic database of theses and in annals of Cardiology congresses and meetings. In total, 40 studies were selected, comprising 122,018 individuals.

Results

Summary estimates of prevalence by the former WHO criteria (BP≥160/95 mmHg) in the 1980’s and 1990’s were 23.6% (95% CI 17.3–31.4%) and 19.6% (16.4–23.3%) respectively. The prevalence of hypertension by the JNC criteria (BP≥140/90 mmHg) in the 1980’s, 1990’s and 2000’s were 36.1% (95% CI 28.7–44.2%), 32.9% (29.9–36.0%), and 28.7% (26.2–31.4%), respectively (P<0.001). In the 2000’s, the pooled prevalence estimates of self-reported hypertension on telephone inquiries was 20.6% (19.0–22.4%), and of self-reported hypertension in home surveys was 25.2% (23.3–27.2%).

Conclusions

The prevalence of hypertension in Brazil seems to have diminished 6% in the last three decades, but it still is approximately 30%. Nationwide surveys by self-reporting by telephone interviews underestimate the real prevalence. Rates of blood pressure control decreased in the same period, corresponding currently to only one quarter of individuals with hypertension.

Spironolactone Versus Clonidine as a Fourth-Drug Therapy for Resistant Hypertension: The ReHOT Randomized Study (Resistant Hypertension Optimal Treatment)

The aim of this study is to compare spironolactone versus clonidine as the fourth drug in patients with resistant hypertension in a multicenter, randomized trial. Medical therapy adherence was checked by pill counting. Patients with resistant hypertension (no office and ambulatory blood pressure [BP] monitoring control, despite treatment with 3 drugs, including a diuretic, for 12 weeks) were randomized to an additional 12-week treatment with spironolactone (12.5-50 mg QD) or clonidine (0.1-0.3 mg BID). The primary end point was BP control during office (<140/90 mm Hg) and 24-h ambulatory (<130/80 mm Hg) BP monitoring. Secondary end points included BP control from each method and absolute BP reduction. From 1597 patients recruited, 11.7% (187 patients) fulfilled the resistant hypertension criteria. Compared with the spironolactone group (n=95), the clonidine group (n=92) presented similar rates of achieving the primary end point (20.5% versus 20.8%, respectively; relative risk, 1.01 [0.55-1.88]; P=1.00). Secondary end point analysis showed similar office BP (33.3% versus 29.3%) and ambulatory BP monitoring (44% versus 46.2%) control for spironolactone and clonidine, respectively. However, spironolactone promoted greater decrease in 24-h systolic and diastolic BP and diastolic daytime ambulatory BP than clonidine. Per-protocol analysis (limited to patients with ≥80% adherence to spironolactone/clonidine treatment) showed similar results regarding the primary end point. In conclusion, clonidine was not superior to spironolactone in true resistant hypertensive patients, but the overall BP control was low (≈21%). Considering easier posology and greater decrease in secondary end points, spironolactone is preferable for the fourth-drug therapy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01643434.

Sarcomere length versus interfilament spacing as determinants of cardiac myofilament Ca2+ sensitivity and Ca2+ binding

The Ca2+ sensitivity of skinned cardiac muscle can be increased by either an increase in sarcomere length or osmotic compression of the myofilament lattice. The length-dependent change in Ca2+ sensitivity is considered to be an important component of the steep force-length relation along the ascending limb of the force-length curve (Frank-Starling relation). Since an increase in sarcomere length is accompanied by a reduction in the spacing between myosin and actin filaments it is not clear whether length-dependent changes in Ca2+ sensitivity are related to changes in sarcomere length, interfilament spacing or some combination of both. To obtain quantitative information on the relative contributions of these two parameters to the determination of Ca2+ sensitivity skinned bovine cardiac muscle bundles of varying sarcomere lengths (1.7-2.3 microns) were exposed to varying concentrations (0-5%) of Dextran T-500. Measurements were made of changes in muscle width in response to Dextran T-500 addition and both force-pCa curves and bound Ca(2+)-pCa curves were obtained as a function of sarcomere length and lattice compression. From the data obtained it was possible to compare Ca2+ sensitivity and Ca(2+)-troponin C affinity at different sarcomere lengths under conditions of changing interfilament spacing and constant interfilament spacing. Both Ca2+ sensitivity and Ca2+ binding correlated more closely with change in interfilament spacing than with change in sarcomere length. These results suggest that length-dependent force generation in cardiac muscle is based primarily on length-dependent changes in the separation between myosin and actin filaments.

Evidence for a force-dependent component of calcium binding to cardiac troponin C

The duration of activation in cardiac muscle is a function of the load. On the basis of studies of Ca2+ transients in muscles subjected to quick release, it has been suggested that force or shortening-mediated changes in Ca2+-troponin C affinity may provide a mechanism for a contraction-activation feedback. This study was designed to test the hypothesis that the formation of force-generating complexes between actin and myosin enhances the affinity of cardiac troponin C for Ca2+. This was done by first establishing the normal relationship between Ca2+ binding and force development in chemically skinned bovine ventricular muscle bundles and then comparing the Ca2+-saturation curves obtained with relaxed and contracting muscle bundles. A double isotope technique was used to measure Ca2+ binding during ATP-induced force generation and during relaxation maintained by the phosphate analogue vanadate. The results showed that the generation of force was associated with an enhanced binding of Ca2+ to the Ca2+-specific regulatory site of cardiac troponin C. These data provide direct evidence that feedback between force and activation in the heart may be mediated by the Ca2+-regulatory site of troponin C.

The site of calcium binding in relation to the activation of myofibrillar contraction

Skeletal muscle myofibrils, in the presence of 2 mM MgCl(2) at pH 7.0, were found to have two classes of calcium-binding sites with apparent affinity constants of 2.1 x 10(6)M(-1) (class 1) and approximately 3 x 10(4)M(-1) (class 2), respectively. At free calcium concentrations essential for the activation of myofibrillar contraction ( approximately 10(-6)M) there would be significant calcium binding only to the class 1 sites. These sites could bind about 1.3 micromoles of calcium per g protein. Extraction of myosin from the myofibrils did not alter their calcium-binding parameters. Myosin A, under identical experimental conditions, had little affinity for calcium. The class 1 sites are, therefore, presumed to be located in the I filaments. The class 1 sites could only be detected in F actin and myosin B preparations which were contaminated with the tropomyosin-troponin complex. Tropomyosin bound very little calcium. Troponin, which in conjunction with tropomyosin confers calcium sensitivity on actomyosin systems, could bind 22 micromoles of calcium per g protein with an apparent affinity constant of 2.4 x 10(6)M(-1). In view of the identical affinity constants of the myofibrils and troponin and the much greater number of calcium-binding sites on troponin it is suggested that calcium activates myofibrillar contraction by binding to the troponin molecule.

Oxytocin and the initiation of human parturition. II. Stimulation of prostaglandin production in human decidua by oxytocin

In the present study we have investigated the effect of oxytocin on the production of prostaglandins E and F (PGE and PGF) by human decidua, amnion, and myometrium in vitro. We found that oxytocin causes a significant increase in the production of both PGE and PGF in the decidua and in the production of PGE in the amnion. In the myometrium the stimulatory effect of oxytocin on PGF production was small and not statistically significant, and PGE production was not affected at all. On the basis of these results, we propose that oxytocin provides the stimulus for the accelerated prostaglandin production in decidua and fetal membranes at the onset of labor. Since oxytocin levels rise in the fetal circulation at this time, the oxytocin stimulus may be of fetal origin as well as of maternal origin.

Multiple gestations and preterm birth

Preterm birth is a major concern in modern obstetrics, and an important source of morbidity and mortality in newborns. Among twin pregnancies, especially, preterm birth is highly prevalent, and it accounts for almost 50% of the complications observed in this obstetrical population. In this article, we review the existing literature regarding the prediction and prevention of preterm birth in both symptomatic and asymptomatic twin pregnancies. In asymptomatic twin pregnancies, the best two predictive tests were cervical length (CL) measurement and cervicovaginal fetal fibronectin (fFN) testing. A single measurement of transvaginal CL at 20-24 weeks of gestation <20 mm or <25 mm is a good predictor of spontaneous preterm birth at <28, <32, and <34 weeks of gestation. A CL beyond 25 mm is associated with a 2% risk for birth before 28 weeks and with a 65% chance for a term pregnancy. Cervicovaginal fFN may be slightly less accurate than CL; however, it has a high negative predictive value in women presenting with threatened preterm labor, as <2% of these women will deliver within one week if the fFN is negative. In symptomatic twin pregnancies, no tests have proven accurate in predicting the risk of preterm birth. For the prevention of preterm birth in asymptomatic twins, regardless of CL, no treatment including bed rest, limitation of home activities, prophylactic tocolysis, progesterone, or cerclage has been shown to reduce the rate of preterm birth. Cervical pessaries might be of interest in cases where there is a short cervix (<25 mm and <38 mm, respectively) but these results need to confirmed in future trials.

Inhibition of premature labor: a multicenter comparison of ritodrine and ethanol

A randomized controlled study was carried out at three medical centers to compare the efficacy and side effects of ethanol and ritodrine in the treatment of threatened premature labor. One hundred and thirty-five patients judged to be between the twentieth and thirty-sixth week of gestation and presenting with clinical symptoms of premature labor were included. Sixty-seven patients were treated with intravenous infusion of 10 per cent ethanol. Sixty-eight patients were treated with intravenous infusion of ritodrine for 12 hours followed by oral ritodrine. If labor recurred prematurely, up to two additional courses of ethanol or ritodrine were given. Delivery was postponed for more than 72 hours in 49 of 67 patients (73 per cent) with ethanol and in 61 of 68 patients (90 per cent) with ritodrine; this difference was significant. Patients in the ethanol group gained a mean of 27.6 days while patients in the ritodrine group gained a mean of 44.0 days. Fifty-four per cent of the ethanol group and 72 per cent of the ritodrine group carried their infants to 36 weeks of gestation. Five infants in the ethanol group and one infant in the ritodrine group died from respiratory distress syndrome. The most frequent side effect of ethanol were nausea and vomiting. The most frequent side effects of ritodrine were tachycardia and blood pressure changes which were easily controlled by lowering the infusion rate. Ethanol and ritodrine were both found to be effective inhibitors of premature labor with ritodrine giving the most favorable results.

Prostaglandins in primary dysmenorrhea. Comparison of prophylactic and nonprophylactic treatment with ibuprofen and use of oral contraceptives

Prostaglandin synthetase inhibitors have been used in clinical trials for the treatment of primary dysmenorrhea on the theory that the disorder may be caused by a high level of prostaglandins. However, a causal role of prostaglandin in dysmenorrhea has not been established, and there is only indirect evidence that the amelioration of dysmenorrhea by prostaglandin synthetase inhibitors is related to their inhibition of prostaglandin synthesis in the uterus. We, therefore, monitored menstrual prostaglandin release in 14 dysmenorrheic patients in a controlled, double-blind, cross-over trial of ibuprofen (Motrin) and in two dysmenorrheic subjects while they were receiving oral contraceptive therapy and while they were not. A total of 89 menstrual cycles were studied. We found that ibuprofen therapy reduced menstrual prostaglandin release and relieved dysmenorrhea but that placebo therapy did not. Oral contraceptives decreased menstrual flow, reduced prostaglandin release and also alleviated dysmenorrhea. We conclude that primary dysmenorrhea is related to a high level of menstrual prostaglandin release. Ibuprofen inhibits prostaglandin synthesis whereas oral contraceptives inhibit ovulation and cyclic endometrial development. Thus, the two drugs suppress endometrial prostaglandin through different mechanisms. Reduction of menstrual prostaglandin release leads to alleviation of dysmenorrhea.

Oxytocin release and plasma anterior pituitary and gonadal hormones in women during lactation

Serial plasma oxytocin (OT), PRL, TSH, FSH, LH, estrone, estradiol, and progesterone were measured by RIA in 12 women before and during a 30-min breast-feeding period on the third or fifth postpartum day. Plasma OT increased significantly from 10.8 +/- 3.4 to 22.4 +/- 3.5 pg/ml (mean +/- SE) within 2 min of suckling (P = less than 0.05) to reach the mean peak level of 53.2 pg/ml at 10 min. The increase in plasma OT was bimodal. Plasma PRL and TSH also increased significantly from baseline levels of 192 +/- 39 ng/ml and 16.9 +/- 5.6 microU/ml, respectively, to reach maximum levels of 427 +/- 91 ng PRL/ml at 10 min (P = less than 0.025) and 281.5 +/- 56.6 microU TSH/ml at 25 min (P = less than 0.005). Plasma FSH-beta (range of means, 3.5-4.6 ng/ml), LH (range of means, 1.7-2.6 mIU/ml), and estradiol (range of means, 29.8-38.2 pg/ml) were low and remained unchanged throughout breast feeding. Plasma progesterone was 6.0 +/- 0.4 ng/ml before breast feeding and did not alter significantly during breast feeding. The significance of these findings is discussed in relation to the milk let-down reflex and the relationship of TSH to PRL.

Hypertensive retinopathy and incident coronary heart disease in high risk men

BACKGROUND/AIM

Although routine ophthalmoscopy is recommended in the evaluation of people with hypertension, the prognostic significance of retinopathy is unknown. The purpose of this study is to determine if hypertensive retinopathy predicts coronary heart disease (CHD).

METHODS

A prospective cohort study involving 560 hypertensive, hyperlipidaemic, middle aged men enrolled in the Lipid Research Clinic's Coronary Primary Prevention Trial. Signs of hypertensive retinopathy (generalised and focal arteriolar narrowing, arteriovenous nicking, widened arteriolar light reflex, retinal haemorrhage and exudates, microaneurysms, and disc swelling) were evaluated by direct funduscopy during a baseline examination by study physicians. Incident CHD events were ascertained from hospital records, necropsy reports, and death certificates, and reviewed by a masked panel of cardiologists.

RESULTS

There were 51 definite CHD events (definite CHD deaths or myocardial infarctions) during a median follow up of 7.8 years. After adjusting for age, blood pressure, electrocardiographic manifestations of left ventricular hypertrophy, cholesterol levels and treatment, glucose and creatinine levels, and smoking status in proportional hazards analysis, the presence of hypertensive retinopathy predicted a doubling of the risk of definite CHD events (relative risk 2.1; 95% confidence interval (CI) 1.0 to 4.2 ). The presence of either generalised or focal arteriolar narrowing predicted almost a tripling of the risk (relative risk 2.9; 95% CI 1.3 to 6.2). Associations were similar for stage 1 hypertension (systolic and diastolic blood pressures of 140-159 and 90-99 mm Hg, respectively) and for other CHD end points.

CONCLUSION

Hypertensive retinopathy predicts CHD in high risk men, independent of blood pressure and CHD risk factors. The data support the concept that retinal microvascular changes are markers of blood pressure damage and may be useful in risk stratification and in the tailoring of hypertension treatment decisions.

Association between alcoholic beverage consumption and incidence of coronary heart disease in whites and blacks: the Atherosclerosis Risk in Communities Study

The authors evaluated the relation between consumption of alcoholic beverages and incidence of coronary heart disease in White and African-American participants in the Atherosclerosis Risk in Communities Study. The average duration of follow-up was 9.8 years between 1987 and 1998. The association was analyzed by means of Cox proportional hazards regression models. The authors found a positive association between ethanol consumption and incident coronary heart disease for Black men (for a 13-g/day increment in ethanol consumption, adjusted hazard ratio (HR) = 1.13, 95% confidence interval (CI): 1.01, 1.28) and an inverse association for White men (HR = 0.88, 95% CI: 0.79, 0.99). There was an inverse association of coronary heart disease with rare drinking (HR = 0.47, 95% CI: 0.28, 0.80) and with consumption of > or =70 g of ethanol per week (HR = 0.49, 95% CI: 0.24, 0.98) in White women and with consumption of > or =210 g/week (HR = 0.56, 95% CI: 0.33, 0.95) in White men. In Black men, the association was positive for consumption of 140-<210 g/week (HR = 2.61, 95% CI: 1.11, 6.17). The contrasting findings in Whites and Black men in this cohort raise the question of whether the cardioprotective effect of alcohol is real or may be confounded by lifestyle characteristics of drinkers.

Oxytocin and the initiation of human parturition. I. Prostaglandin release during induction of labor by oxytocin

Concentrations of plasma prostaglandins E and F and the 15-keto-13,14 dihydrometabolite of PGF2 alpha (PGFM) were determined by radioimmunoassay in 15 women who underwent induction of labor with oxytocin. Plasma PGFM rose significantly during the oxytocin infusion in nine women who went on to deliver vaginally but did not change in six women in whom induction of labor failed. Plasma PGE and PGF levels also rose during the infusion in the nine women with successful induction of labor but the changes were not statistically significant. In comparison to the six women in whom induction failed, however, plasma PGE in the nine women with successful induction reached significantly higher levels. Oxytocin infusions elicited uterine contractions of similar frequency in both groups of women, but the cervix failed to dilate in the six women in whom induction failed. The oxytocin-induced rise in plasma PGFM is, therefore, not simply a consequence of uterine contractions. We suggest that oxytocin stimulates PGF production in the pregnant uterus when it is appropriately sensitized to oxytocin, causing a potentiation of the oxytocin-induced contractions which is necessary for the contractions to become efficient in dilating the cervix. We further suggest that the stimulation of PGF production by oxytocin is mediated by oxytocin receptors, probably in the decidua.