Circadian Rhythm of Blood Pressure Challenges Office Values as the “Gold Standard” in the Diagnosis of Gestational Hypertension

Despite poor sensitivity and specificity, office blood pressure (BP) determinations are still the “gold standard” for diagnosing gestational hypertension. This prospective blind study evaluates the prognostic value of office values as compared with ambulatory monitoring in pregnancy. We analyzed 2175 BP series systematically sampled from 355 non-preeclamptic pregnant women for 48 h every 4 wks from the first hospital visit until delivery. Women were divided for comparative purposes into three groups: “detected” gestational hypertension, defined on the basis of casual clinical BP>140/90 mm Hg after 20 wks of gestation and hyperbaric index (area of BP excess above the upper limit of a time-specified tolerance interval adjusted for the circadian pattern of the reference population) consistently above the threshold for diagnosing hypertension in pregnancy; “undetected” gestational hypertension, women with office BP<140/90 mm Hg but hyperbaric index consistently above the threshold for diagnosis; and normotension, women with both office values and hyperbaric index below the respective thresholds for diagnosis. Small and insignificant differences in the 24 h mean BP between “detected” and “undetected” gestational hypertension is observed in all trimesters, in contrast with highly significant differences between these two groups and normotensive pregnancies. Normotensive women are characterized by highly significant lesser incidence by 60% in preterm delivery, 70% in intrauterine growth retardation, and 50% in delivery by cesarean section (P<0.001) compared with women with “detected” and “undetected” gestational hypertension (P>0.715). In pregnancy, the hyperbaric index is markedly superior to office BP measurements for diagnosis of what should be truly considered gestational hypertension, and for prediction of the outcome of pregnancy.     

Ambulatory Blood Pressure Monitoring for the Early Identification of Hypertension in Pregnancy

Gestational hypertension and preeclampsia are major contributors to perinatal morbidity and mortality. The diagnosis of gestational hypertension still relies on conventional clinic blood pressure (BP) measurements and thresholds of ≥140/90?mm Hg for systolic (SBP)/diastolic (DBP) BP. However, the correlation between BP level and target organ damage, cardiovascular disease risk, and long-term prognosis is greater for ambulatory BP monitoring (ABPM) than clinic BP measurement. Accordingly, ABPM has been suggested as the logical approach to overcoming the low sensitivity and specificity of clinic BP measurements in pregnancy. With the use of ABPM, differing predictable BP patterns throughout gestation have been identified for clinically healthy and hypertensive pregnant women. In normotensive pregnancies, BP steadily decreases up to the middle of gestation and then increases up to the day of delivery. In contrast, women who develop gestational hypertension or preeclampsia show stable BP during the first half of pregnancy and a continuous linear BP increase thereafter until delivery. Epidemiologic studies have also consistently reported sex differences in the 24-h patterns of ambulatory BP and heart rate. Typically, men exhibit a lower heart rate and higher BP than women, the differences being larger for SBP than DBP. Additionally, as early as in the first trimester of gestation, statistically significant increased 24-h SBP and DBP means characterize women complicated with gestational hypertension or preeclampsia compared with women with uncomplicated pregnancies. However, the normally lower BP in nongravid women as compared with men, additional decrease in BP during the second trimester of gestation in normotensive but not in hypertensive pregnant women, and significant differences in the 24-h BP pattern between healthy and complicated pregnancies at all gestational ages have not been taken into consideration when establishing reference BP thresholds for the diagnosis of hypertension in pregnancy. Several studies reported that use of the 24-h BP mean is not a proper test for an individualized early diagnosis of hypertension in pregnancy defined on the basis of cuff BP measurements, thus concluding that from such an awkward approach ABPM is not useful in pregnancy. The 24-h BP pattern that characterizes healthy pregnant women at all gestational ages suggests the use for diagnosis of a time-specified reference limit reflecting that mostly predictable BP variability. Once the time-varying threshold, given, for instance, by the upper limit of a tolerance interval, is available, the hyperbaric index (HBI), as a determinant of BP excess, can be calculated as the total area of any given subject's BP above the threshold. This tolerance-hyperbaric test, where diagnosis of gestational hypertension is based on the HBI calculated with reference to a time-specified tolerance limit, has been shown to provide high sensitivity and specificity for the early identification of subsequent hypertension in pregnancy, as well as a valuable approach for prediction of pregnancy outcome. ABPM during gestation, starting preferably at the time of the first obstetric check-up following positive confirmation of pregnancy, provides sensitive endpoints for use in early risk assessment and guide for establishing prophylactic or therapeutic intervention, and should thus be regarded as the required standard for the diagnosis of hypertension in pregnancy. (Author correspondence: rhermida@uvigo.es)     

Chronotherapy With Low-Dose Aspirin for Prevention of Complications in Pregnancy

Preeclampsia and gestational hypertension are major contributors to perinatal morbidity and mortality. Several studies aimed to test the effects of low-dose aspirin (ASA) in the prevention of preeclampsia concluded that the beneficial effects of such treatment outweigh adverse ones. Such benefits have not been fully corroborated by larger randomized trials usually carried out in low-risk women, testing a dose of 60?mg/d ASA presumably ingested in the morning, and including women randomized as late as at 26–32 wks of gestation. The authors conducted a prospective, randomized, double-blind, placebo-controlled, chronotherapy trial on 350 high-risk pregnant women (183 nulliparous), 30.7?±?5.3 (mean?±?SD) yrs of age, and 13.5?±?1.4 wks of gestation at the time of recruitment. Women were randomly assigned to one of six groups, defined according to treatment (placebo or ASA, 100?mg/d) and time of treatment: upon awakening, 8?h after awakening, or at bedtime. Intervention started at 12–16 wks of gestation and continued until delivery. Blood pressure (BP) was measured by ambulatory monitoring (ABPM) for 48-h at baseline, every 4 wks until the 7th month of gestation, every 2 wks thereafter until delivery, and at puerperium. The effects of ASA on ambulatory BP were markedly dependent on administration time: there was no effect on BP, compared with placebo, when ASA was ingested upon awakening, but the BP reduction was highly statistically significant when low-dose ASA was ingested 8?h after awakening and, to a greater extent, at bedtime (p?<?.001). At puerperium, 6–8 wks after discontinuation of treatment, there was no statistically significant difference in 24-h BP means between the groups of women who ingested ASA at different circadian times. Women ingesting low-dose ASA, compared with placebo, evidenced a significantly lower hazard ratio (HR) of serious adverse outcomes, a composite of preeclampsia, preterm delivery, intrauterine growth retardation (IUGR), and stillbirth (.35, 95% confidence interval [CI]: .22–.56; p?<?.001). The HR of individual outcome variables, i.e., preeclampsia, preterm delivery, IUGR, and gestational hypertension, were also significantly lower with ASA versus placebo (p always?<?.041). There were small and nonsignificant differences in outcomes between placebo and low-dose ASA ingested upon awakening. These four groups combined showed highly significant greater event rate of serious adverse outcomes than women ingesting ASA either in the evening or at bedtime (HR: .19, 95% CI: .10–.39; p?<?.001). There was no increased risk of hemorrhage, either before or after delivery, with low-dose ASA relative to placebo (HR: .57, 95% CI: .25–1.33; p =?.194). Results indicate that (i) 100?mg/d ASA should be the recommended minimum dose for prevention of complications in pregnancy; (ii) ingestion of low-dose ASA should start at ≤16 wks of gestation; and (iii) low-dose ASA ingested at bedtime, but not upon awakening, significantly regulates ambulatory BP and reduces the incidence of preeclampsia, gestational hypertension, preterm delivery, and IUGR. ABPM evaluation at the first trimester of pregnancy provides sensitive endpoints for identification of women at high risk for preeclampsia who might benefit most from the cost-effective preventive intervention with timed low-dose ASA. (Author correspondence: rhermida@uvigo.es)     

Circadian Blood Pressure Variability in Normotensive Pregnant Women as a Function of Parity,Maternal Age,and Stage of Gestation

Studies based on conventional office blood pressure (BP) measurements concluded that both maternal age and parity have significant effects on BP during pregnancy. Previous results have also indicated predictable trends of BP variability with gestational age. Accordingly, we have evaluated possible differences in the circadian pattern of ambulatory BP as a function of parity, maternal age, and stage of gestation in normotensive women who were systematically studied by ambulatory BP monitoring during their pregnancies. We analyzed 1408 BP profiles obtained from 126 nulliparous and 109 multiparous pregnant women sampled for 48 consecutive h every 4 weeks from the first obstetric visit (usually within the first trimester of pregnancy) until delivery. Data were divided for comparative analysis according to parity (nulliparous versus multiparous), age (≤25, 26–30, 31–35, and ≥36 yrs), and trimester of gestation. Circadian BP parameters established by population multiple‐components analysis were compared between groups using a nonparametric test. A highly statistically significant circadian pattern described by a model that includes components with periods of 24 and 12 h is demonstrated for systolic and diastolic BP for all groups of pregnant women in all trimesters (always p<0.001). There was no significant difference in the 24 h mean among groups divided by parity at any age or stage of pregnancy. A trend of increasing BP with age was found for diastolic but not for systolic BP. Although statistically significant, differences in the 24 h mean of diastolic BP among groups divided by age were always less than 2 mm Hg. Data obtained from systematic ambulatory monitoring in normotensive pregnant women indicate the lack of differences in BP according to parity. The small, although significant, increase in diastolic BP with age may have scarce influence in the proper identification of women with gestational hypertension. Reference thresholds for BP to be used in the early identification of hypertensive complications in pregnancy could thus be developed as a function of the rest‐activity cycle and gestational age only, and independently of parity or maternal age.     

Circadian blood pressure variability in normotensive pregnant women as a function of parity, maternal age, and stage of gestation

Studies based on conventional office blood pressure (BP) measurements concluded that both maternal age and parity have significant effects on BP during pregnancy. Previous results have also indicated predictable trends of BP variability with gestational age. Accordingly, we have evaluated possible differences in the circadian pattern of ambulatory BP as a function of parity, maternal age, and stage of gestation in normotensive women who were systematically studied by ambulatory BP monitoring during their pregnancies. We analyzed 1408 BP profiles obtained from 126 nulliparous and 109 multiparous pregnant women sampled for 48 consecutive h every 4 weeks from the first obstetric visit (usually within the first trimester of pregnancy) until delivery. Data were divided for comparative analysis according to parity (nulliparous versus multiparous), age (< or = 25, 26-30, 31-35, and > or = 36 yrs), and trimester of gestation. Circadian BP parameters established by population multiple-components analysis were compared between groups using a nonparametric test. A highly statistically significant circadian pattern described by a model that includes components with periods of 24 and 12h is demonstrated for systolic and diastolic BP for all groups of pregnant women in all trimesters (always p < 0.001). There was no significant difference in the 24h mean among groups divided by parity at any age or stage of pregnancy. A trend of increasing BP with age was found for diastolic but not for systolic BP. Although statistically significant, differences in the 24h mean of diastolic BP among groups divided by age were always less than 2 mm Hg. Data obtained from systematic ambulatory monitoring in normotensive pregnant women indicate the lack of differences in BP according to parity. The small, although significant, increase in diastolic BP with age may have scarce influence in the proper identification of women with gestational hypertension. Reference thresholds for BP to be used in the early identification of hypertensive complications in pregnancy could thus be developed as a function of the rest-activity cycle and gestational age only, and independently of parity or maternal age.     

Arterial hypertension assessed “out-of-office” in a contemporary cohort of rheumatoid arthritis patients free of cardiovascular disease is characterized by high prevalence,low awareness,poor control and increased vascular damage-associated “white coat” phenomenon

Introduction

Rheumatoid arthritis (RA) is associated with a high cardiovascular disease (CVD) risk, whereas arterial hypertension is a major modifiable CVD risk factor with still unclear prevalence in RA disease. We conducted a comprehensive study on hypertension characteristics evaluating for the first time out-of-office blood pressure (BP) in a typical contemporary RA cohort.

Methods

Assessment of office and out-of-office BP (when office systolic/diastolic BP was >129/79) and vascular studies including evaluation of aortic stiffness, carotid hypertrophy/plaques and ankle-brachial index, were performed in 214 consecutive, consenting RA patients free of CVD (aged 58.4 ± 12.3 years, 82% women). As comparators regarding office hypertension measurements, data from 214 subjects (1:1 matched for age and gender with the RA patients) derived from a cohort designed to assess the prevalence of hypertension in the general population were used.

Results

The prevalence of declared known hypertension in the RA population was 44%. Of the remaining RA patients, 2 in every 5 individuals had abnormal office BP (systolic/diastolic >139/89 mmHg), contributing to almost double the prevalence of declared/office hypertension compared to the general matched population (67% vs. 34%). Out-of-office (home or ambulatory 24 hour) BP measurements revealed that: (i) a 54% prevalence of actual hypertension in RA, in other words almost 10% of the patients were unaware of having hypertension and (ii) 29% of the RA patients with known hypertension were not well controlled. Actual hypertension was positively associated with age and body mass index, and inversely with the use of biologic drugs. Overall, almost 1 out of 5 presented the ''white coat’ phenomenon. An intermediately compromised vascular phenotype was evident in this “white coat” subgroup (lying between patients with sustained normotension and sustained hypertension) in terms of aortic stiffness, carotid hypertrophy and ankle-brachial index, even after adjustment for confounders.

Conclusion

Beyond any doubt on the basis of out-of-office evaluation, arterial hypertension in RA has a high prevalence, low awareness and poor control, as well as substantial and vascular damage-associated “white coat” phenomenon. Thus, correct diagnosis and effective treatment of hypertension is of key importance in RA for CVD risk reduction.     

Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy

OBJECTIVE: To provide Canadian physicians with comprehensive, evidence-based guidelines for the nonpharmacologic management and prevention of gestational hypertension and pre-existing hypertension during pregnancy. OPTIONS: Lifestyle modifications, dietary or nutrient interventions, plasma volume expansion and use of prostaglandin precursors or inhibitors. OUTCOMES: In gestational hypertension, prevention of complications and death related to either its occurrence (primary or secondary prevention) or its severity (tertiary prevention). In pre-existing hypertension, prevention of superimposed gestational hypertension and intrauterine growth retardation. EVIDENCE: Articles retrieved from the pregnancy and childbirth module of the Cochrane Database of Systematic Reviews; pertinent articles published from 1966 to 1996, retrieved through a MEDLINE search; and review of original randomized trials from 1942 to 1996. If evidence was unavailable, consensus was reached by the members of the consensus panel set up by the Canadian Hypertension Society. VALUES: High priority was given to prevention of adverse maternal and neonatal outcomes in pregnancies with established hypertension and in those at high risk of gestational hypertension through the provision of effective nonpharmacologic management. BENEFITS, HARMS AND COSTS: Reduction in rate of long-term hospital admissions among women with gestational hypertension, with establishment of safe home-care blood pressure monitoring and appropriate rest. Targeting prophylactic interventions in selected high-risk groups may avoid ineffective use in the general population. Cost was not considered. RECOMMENDATION: Nonpharmacologic management should be considered for pregnant women with a systolic blood pressure of 140-150 mm Hg or a diastolic pressure of 90-99 mm Hg, or both, measured in a clinical setting. A short-term hospital stay may be required for diagnosis and for ruling out severe gestational hypertension (preeclampsia). In the latter case, the only effective treatment is delivery. Palliative management, dependent on blood pressure, gestational age and presence of associated maternal and fetal risk factors, includes close supervision, limitation of activities and some bed rest. A normal diet without salt restriction is advised. Promising preventive interventions that may reduce the incidence of gestational hypertension, especially with proteinuria, include calcium supplementation (2 g/d), fish oil supplementation and low-dose acetylsalicylic acid therapy, particularly in women at high risk for early-onset gestational hypertension. Pre-existing hypertension should be managed the same way as before pregnancy. However, additional concerns are the effects on fetal well-being and the worsening of hypertension during the second half of pregnancy. There is, as yet, no treatment that will prevent exacerbation of the condition. VALIDATION: The guidelines share the principles in consensus reports from the US and Australia on the nonpharmacologic management of hypertension in pregnancy.     

Risk of development of diabetes mellitus after diagnosis of gestational diabetes

Background

It is generally appreciated that gestational diabetes is a risk factor for type 2 diabetes. However, the precise relation between these 2 conditions remains unknown. We sought to determine the incidence of diabetes mellitus after diagnosis of gestational diabetes.

Methods

We used a population-based database to identify all deliveries in the province of Ontario over the 7-year period from Apr. 1, 1995, to Mar. 31, 2002. We linked these births to mothers who had been given a diagnosis of gestational diabetes through another administrative database that records people with diabetes on the basis of either physician service claims or hospital admission records. We examined database records for these women from the time of delivery until Mar. 31, 2004, a total of 9 years. We determined the presence of diabetes mellitus according to a validated administrative database definition for this condition.

Results

We identified 659 164 pregnant women who had no pre-existing diabetes. Of these, 21 823 women (3.3%) had a diagnosis of gestational diabetes. The incidence of gestational diabetes rose significantly over the 9-year study period, from 3.2% in 1995 to 3.6% in 2001 (p < 0.001). The probability of diabetes developing after gestational diabetes was 3.7% at 9 months after delivery and 18.9% at 9 years after delivery. After adjustment for age, urban or rural residence, neighbourhood income quintile, whether the woman had a previous pregnancy, whether the woman had hypertension after the index delivery, and primary care level before the index delivery, the most significant risk factor for diabetes was having had gestational diabetes during the index pregnancy (hazard ratio 37.28, 95% confidence interval 34.99–40.88; p < 0.001). Age, urban residence and lower income were also important factors. When analyzed by year of delivery, the rate of development of diabetes was higher among the latest subcohort of women with gestational diabetes (delivery during 1999–2001) than among the earliest subcohort (delivery during 1995 or 1996) (16% by 4.7 years after delivery v. 16% by 9.0 years).

Interpretation

In this large population-based study, the rate of development of diabetes after gestational diabetes increased over time and was almost 20% by 9 years. This estimate should be used by clinicians to assist in their counselling of pregnant women and by policy-makers to target these women for screening and preventionRecently, the US Centers for Disease Control and Prevention predicted a 3-fold rise in the prevalence of diabetes mellitus in the United States between 2005 and 2050, from 16.2 million to 48.3 million.¹ Although evidence to support population-based screening as an approach to stem this epidemic is lacking, targeted screening of high-risk populations has been advocated.^2–5 One group at very high risk for diabetes consists of women with a history of gestational diabetes.During pregnancy, women with gestational diabetes display metabolic abnormalities similar to those of people with type 2 diabetes mellitus, such as insulin resistance and reduced β-cell compensation for that resistance.⁶ After delivery, most of these women return to a euglycemic state, but they are at increased risk for overt type 2 diabetes in the future. The rates of development of type 2 diabetes among women with previous gestational diabetes quoted in the literature have been extremely variable, between 3% and 70%.^7–11 Aside from genetic differences among populations, this large variation in the subsequent development of type 2 diabetes may also be due to the use of diverse tests for glucose tolerance in pregnancy, selection bias and, in particular, duration of follow-up.⁹In light of a growing body of evidence that it is possible to delay the development of diabetes among those at high risk,^12–16 it is important to determine the true risk of type 2 diabetes by means of a population-based study; this will allow accurate assessment of the cost-effectiveness and appropriateness of postpartum case management and screening. We sought to determine the incidence of diabetes mellitus in the years following a diagnosis of gestational diabetes.     

Maternal Prepregnancy Body Mass Index and Gestational Weight Gain on Pregnancy Outcomes

Objective

The aim of the present study was to evaluate the single and joint associations of maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) with pregnancy outcomes in Tianjin, China.

Methods

Between June 2009 and May 2011, health care records of 33,973 pregnant women were collected and their children were measured for birth weight and birth length. The independent and joint associations of prepregnancy BMI and GWG based on the Institute of Medicine (IOM) guidelines with the risks of pregnancy and neonatal outcomes were examined by using Logistic Regression.

Results

After adjustment for all confounding factors, maternal prepregnancy BMI was positively associated with risks of gestational diabetes mellitus (GDM), pregnancy-induced hypertension, caesarean delivery, preterm delivery, large-for-gestational age infant (LGA), and macrosomia, and inversely associated with risks of small-for-gestational age infant (SGA) and low birth weight. Maternal excessive GWG was associated with increased risks of pregnancy-induced hypertension, caesarean delivery, LGA, and macrosomia, and decreased risks of preterm delivery, SGA, and low birth weight. Maternal inadequate GWG was associated with increased risks of preterm delivery and SGA, and decreased risks of LGA and macrosomia, compared with maternal adequate GWG. Women with both prepregnancy obesity and excessive GWG had 2.2–5.9 folds higher risks of GDM, pregnancy-induced hypertension, caesarean delivery, LGA, and macrosomia compared with women with normal prepregnancy BMI and adequate GWG.

Conclusions

Maternal prepregnancy obesity and excessive GWG were associated with greater risks of pregnancy-induced hypertension, caesarean delivery, and greater infant size at birth. Health care providers should inform women to start the pregnancy with a BMI in the normal weight category and limit their GWG to the range specified for their prepregnancy BMI.     

Hypertensive Disorders of Pregnancy: A Systematic Review of International Clinical Practice Guidelines

Background

Clinical practice guidelines (CPGs) are developed to assist health care providers in decision-making. We systematically reviewed existing CPGs on the HDPs (hypertensive disorders of pregnancy) to inform clinical practice.

Methodology & Principal Findings

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, Health Technology Assessments, and Database of Abstracts of Reviews of Effects (Ovid interface), Grey Matters, Google Scholar, and personal records were searched for CPGs on the HDPs (Jan/03 to Nov/13) in English, French, Dutch, or German. Of 13 CPGs identified, three were multinational and three developed for community/midwifery use. Length varied from 3–1188 pages and three guidelines did not formulate recommendations. Eight different grading systems were identified for assessing evidence quality and recommendation strength. No guideline scored ≧80% on every domain of the AGREE II, a tool for assessing guideline methodological quality; two CPGs did so for 5/6 domains. Consistency was seen for (i) definitions of hypertension, proteinuria, chronic and gestational hypertension; (ii) pre-eclampsia prevention for women at increased risk: calcium when intake is low and low-dose aspirin, but not vitamins C and E or diuretics; (iii) antihypertensive treatment of severe hypertension; (iv) MgSO4 for eclampsia and severe pre-eclampsia; (v) antenatal corticosteroids at <34 wks when delivery is probable within 7 days; (vi) delivery for women with severe pre-eclampsia pre-viability or pre-eclampsia at term; and (vii) active management of the third stage of labour with oxytocin. Notable inconsistencies were in: (i) definitions of pre-eclampsia and severe pre-eclampsia; (ii) target BP for non-severe hypertension; (iii) timing of delivery for women with pre-eclampsia and severe pre-eclampsia; (iv) MgSO4 for non-severe pre-eclampsia, and (v) postpartum maternal monitoring.

Conclusions

Existing international HDP CPGs have areas of consistency with which clinicians and researchers can work to develop auditable standards, and areas of inconsistency that should be addressed by future research.     

Impairment of endothelial function in women with a history of preeclampsia: an indicator of cardiovascular risk

Preeclampsia is a disorder of pregnancy diagnosed by gestational hypertension and proteinuria. Epidemiological evidence suggests that women who experience preeclampsia are at a greater risk of hypertension and heart disease later in life compared with women who had normal pregnancies. Our objective was to determine whether endothelial function is impaired in postpartum women with a history of preeclampsia in their first pregnancy. We measured forearm blood flow (FBF) by venous occlusion plethysmography in 50 healthy women: 16 with prior preeclampsia, 14 with a prior normotensive pregnancy, and 20 never pregnant controls. The postpartum women participated 6-12 mo after delivery. Heart rate (HR) and blood pressure (BP) were concurrently monitored on the contralateral arm. Hemodynamic variables were assessed at baseline and during a mental stress test known to elicit endothelium-dependent vasodilatation. We found that baseline FBF, HR, systolic BP, and diastolic BP did not significantly differ among the groups, whereas mean arterial pressure in the preeclamptic group was greater than that of the normal pregnancy group (P = 0.03). Stress-induced FBF (percent change over baseline) was reduced in the preeclamptic group compared with both the normal pregnancy and never pregnant groups (P = 0.06) and was significantly attenuated compared with women with prior normal pregnancies (91% vs. 147%, P = 0.006). These data demonstrate that women with a history of preeclampsia exhibit impaired endothelial function up to 1 yr postpartum. This observation may explain their increased risk for hypertension and cardiovascular disease.     

Joint and Independent Associations of Gestational Weight Gain and Pre-Pregnancy Body Mass Index with Outcomes of Pregnancy in Chinese Women: A Retrospective Cohort Study

Objective

To explore the joint and independent effects of gestational weight gain (GWG) and pre-pregnancy body mass index (BMI) on pregnancy outcomes in a population of Chinese Han women and to evaluate pregnant women’s adherence to the 2009 Institute of Medicine (IOM) gestational weight gain guidelines.

Methods

This was a multicenter, retrospective cohort study of 48,867 primiparous women from mainland China who had a full-term singleton birth between January 1, 2011 and December 30, 2011. The independent associations of pre-pregnancy BMI, GWG and categories of combined pre-pregnancy BMI and GWG with outcomes of interest were examined using an adjusted multivariate regression model. In addition, women with pre-pregnancy hypertension were excluded from the analysis of the relationship between GWG and delivery of small-for-gestational-age (SGA) infants, and women with gestational diabetes (GDM) were excluded from the analysis of the relationship between GWG and delivery of large-for-gestational-age (LGA) infants.

Results

Only 36.8% of the women had a weight gain that was within the recommended range; 25% and 38.2% had weight gains that were below and above the recommended range, respectively. The contribution of GWG to the risk of adverse maternal and fetal outcomes was modest. Women with excessive GWG had an increased likelihood of gestational hypertension (adjusted OR 2.55; 95% CI = 1.92–2.80), postpartum hemorrhage (adjusted OR 1.30; 95% CI = 1.17–1.45), cesarean section (adjusted OR 1.31; 95% CI = 1.18–1.36) and delivery of an LGA infant (adjusted OR 2.1; 95% CI = 1.76–2.26) compared with women with normal weight gain. Conversely, the incidence of GDM (adjusted OR 1.64; 95% CI = 1.20–1.85) and SGA infants (adjusted OR 1.51; 95% CI = 1.32–1.72) was increased in the group of women with inadequate GWG. Moreover, in the obese women, excessive GWG was associated with an apparent increased risk of delivering an LGA infant. In the women who were underweight, poor weight gain was associated with an increased likelihood of delivering an SGA infant. After excluding the mothers with GDM or gestational hypertension, the ORs for delivery of LGA and SGA infants decreased for women with high GWG and increased for women with low GWG.

Conclusions

GWG above the recommended range is common in this population and is associated with multiple unfavorable outcomes independent of pre-pregnancy BMI. Obese women may benefit from avoiding weight gain above the range recommended by the 2009 IOM. Underweight women should avoid low GWG to prevent delivering an SGA infant. Pregnant women should therefore be monitored to comply with the IOM recommendations and should have a balanced weight gain that is within a range based on their pre-pregnancy BMI.     

Women With Hypertensive Pregnancies Have Difficulties in Regaining Pre‐pregnancy Weight and Show Metabolic Disturbances

The aim was to determine maternal weight gain and body composition during pregnancy and 3 months postpartum in women with uncomplicated singleton and twin pregnancies and in women with gestational diabetes (GDM) and gestational hypertension (GH). This prospective study includes four groups of subjects: those with an uncomplicated pregnancy (n = 32), those with a diagnosis of GH (n = 28), those with a diagnosis of GDM (n = 52), and those with twin pregnancy (n = 11). Their body compositions were estimated by a bioimpedance analysis and fasting lipids and glucose levels were determined during the pregnancy and 3 months after pregnancy. Women with GDM were 11.7 kg heavier than the reference group before pregnancy, whereas weight before pregnancy was not different in other investigated groups. Weight loss after delivery was attenuated in GH group. Percentage body fat remained elevated in women with GDM (34.1 ± 7.0%) and hypertension (31.5 ± 6.4%) at 3 months after pregnancy. Also their total cholesterol and low‐density lipoprotein (LDL)‐cholesterol levels as well as fasting glucose remained elevated in comparison to values of the reference group. In conclusion, women with hypertensive pregnancies, though not overweight before pregnancy, gain and retain excess gestational weight and this leads to metabolic abnormalities similar to those seen in women GDM. Thus, postpartum period appears to be critical for weight management and interventional programs are called for.     

Non-dipper treated hypertensive patients do not have increased cardiac structural alterations

Background

Non-dipping pattern in hypertensive patients has been shown to be associated with an excess of target organ damage and with an adverse outcome. The aim of our study was to assess whether a reduced nocturnal fall in blood pressure (BP), established on the basis of a single 24-h BP monitoring, in treated essential hypertensives is related to more prominent cardiac alterations.

Methods

We enrrolled 229 treated hypertensive patients attending the out-patient clinic of our hypertension centre; each patient was subjected to the following procedures : 1) clinic BP measurement; 2) blood and urine sampling for routine blood chemistry and urine examination; 3) standard 12-lead electrocardiogram; 4) echocardiography; 5) ambulatory BP monitoring (ABPM). For the purpose of this study ABPM was carried-out in three subgroups with different clinic BP profile : 1) patients with satisfactory BP control (BP < 140/90 mmHg; group I, n = 58); 2) patients with uncontrolled clinic BP (clinic BP values ≥ 140 and/or 90 mmHg) but lower self-measured BP (< 20 mmHg for systolic BP and/or 10 mmHg for diastolic BP; group II, n = 72); 3) patients with refractory hypertension, selected according to WHO/ISH guidelines definition (group III, n = 99). Left ventricular hypertrophy (LVH) was defined by two gender-specific criteria (LV mass index ≥125/m² in men and 110 g/m² in women, ≥51/gm^2.7 in men and 47/g/m^2.7 in women).

Results

Of the 229 study participants 119 (51.9%) showed a fall in SBP/DBP < 10% during the night (non-dippers). The prevalence of non-dippers was significantly lower in group I (44.8%) and II (41.6%) than in group III (63.9%, p < 0.01 III vs II and I). The prevalence of LVH varied from 10.3 to 24.1% in group I, 31.9 to 43.1% in group II and from 60.6 to 67.7% in group III (p < 0.01, III vs II and I). No differences in cardiac structure, analysed as continuous variable as well as prevalence of LVH, were found in relationship to dipping or non-dipping status in the three groups.

Conclusions

In treated essential hypertensives with or without BP control the extent of nocturnal BP decrease is not associated with an increase in LV mass or LVH prevalence; therefore, the non-dipping profile, diagnosed on the basis of a single ABPM, does not identify hypertensive patients with greater cardiac damage.     

Hypertensive diseases of pregnancy and risk of hypertension and stroke in later life: results from cohort study

ObjectiveTo examine the association between hypertensive diseases of pregnancy (gestational hypertension and pre-eclampsia) and the development of circulatory diseases in later life.DesignCohort study of women who had pre-eclampsia during their first singleton pregnancy. Two comparison groups were matched for age and year of delivery, one with gestational hypertension and one with no history of raised blood pressure.SettingMaternity services in the Grampian region of Scotland.ParticipantsWomen selected from the Aberdeen maternity and neonatal databank who were resident in Aberdeen and who delivered a first, live singleton from 1951 to 1970.ResultsThere were significant positive associations between pre-eclampsia/eclampsia or gestational hypertension and later hypertension in all measures. The adjusted relative risks varied from 1.13-3.72 for gestational hypertension and 1.40-3.98 for pre-eclampsia or eclampsia. The adjusted incident rate ratio for death from stroke for the pre-eclampsia/eclampsia group was 3.59 (95% confidence interval 1.04 to 12.4).ConclusionsHypertensive diseases of pregnancy seem to be associated in later life with diseases related to hypertension. If greater awareness of this association leads to earlier diagnosis and improved management, there may be scope for reducing a proportion of the morbidity and mortality from such diseases.

What is already known on this topic

Much is known about the effect of cardiovascular risks factors that are shared by men and women, but less on those specific to womenRetrospective studies, based on patient recall, suggest that hypertension in pregnancy may be associated with increased risk of cardiovascular diseases in later life

What this study adds

Prospective recording of blood pressure and proteinuria shows that women who experienced raised blood pressure in pregnancy have a long term risk of hypertensionWomen who experience raise blood pressure in pregnancy have an increased risk of stroke and, to a lesser extent, an increased risk of ischaemic heart diseaseLong term cardiovascular risks are greater for women who had pre-eclampsia than those who experienced gestational hypertension (hypertension without proteinuria)     

妊娠高血压疾病对妊娠结局的影响及防治对策探讨

目的：研究妊娠高血压疾病对妊娠结局的影响及防治对策讨论。方法：选择回顾性研究方法,选择2010年9月到2012年8月到我院的妊娠高血压患者60名作为观察组,并且同期选择60名正常妊娠妇女作为对照组,比较妊娠高血压患者的母体并发症（早产、胎盘早剥、产后出血）等及胎儿妊娠结局等情况与对照组的比较。结果：妊娠高血压患者不同程度对妊娠结局的影响不同P〈0．05,并且妊娠高血压患者的母体并发症与对新生儿的影响与对照组比较有差异P〈0．05,异常情况均较正常妊娠妇女要高。结论：妊娠高血压患者对妊娠结局的影响较为严重,对母婴危害严重,需积极预防。     

The tolerance-hyperbaric test: a chronobiologic approach for improved diagnosis of hypertension

Blood pressure (BP) displays predictable large-amplitude circadian variability. Thus, the identification and the proper definition of hypertension are highly ambiguous when based on single time-unspecified measurements. One way to deal with such variability in the diagnosis of hypertension is to replace the commonly used constant limits of BP by a time-specified reference interval based on the normal circadian BP rhythm assessed by ambulatory BP monitoring (ABPM). A proper reference limit can be constructed, for instance, as a tolerance interval computed for every specific time interval throughout the 24 h. Once such a threshold (given by the upper limit of the tolerance interval) is constructed, a hyperbaric index (HBI) can be computed by numerical integration of the total area of any given patient's BP profile above threshold. The HBI plus the duration of excess within the 24h day serves as nonparametric endpoints for assessing hypertension. Both retrospective and prospective evaluation of this tolerance-hyperbaric test validate its high sensitivity and specificity in the diagnosis of hypertension. We describe the theory of the HBI as well as a newly created dedicated software program that automatically derives the tolerance intervals from a reference database of normotensive subjects and calculates the HBI and other potentially valuable parameters based on data obtained by ABPM. The establishment of time-qualified tolerance limits and the assessment of the extent and timing of BP elevation represents a valuable tool for the more accurate diagnosis of hypertension as well as means of gauging response to treatment.     

Time trends in blood pressure, body mass index and smoking in the vietnamese population: a meta-analysis from multiple cross-sectional surveys

Introduction

Data for trends in cardiovascular disease (CVD) risk factors are needed to set priorities and evaluate intervention programmes in the community. We estimated time trends in blood pressure (BP), anthropometric variables and smoking in the Vietnamese population and highlighted the differences between men and women or between rural and urban areas.

Methods

A dataset of 23,563 adults aged 25–74 from 5 cross-sectional surveys undertaken within Vietnam from 2001 to 2009 by the Vietnam National Heart Institute was used to estimate mean BP, weight, waist circumference (WC), body mass index (BMI), the prevalence of hypertension, adiposity or smoking, which were standardised to the national age structure of 2009. Multilevel mixed linear models were used to estimate annual changes in the variables of interest, adjusted by age, sex, residential area, with random variations for age and surveyed provinces.

Findings

Among the adult population, the age-standardised mean systolic and diastolic BP increased by 0.8 and 0.3 mmHg in women, 1.1 and 0.4 mmHg in men, while the mean BMI increased by 0.1 kgm⁻² in women, 0.2 kgm⁻² in men per year. Consequently, the prevalence of hypertension and adiposity increased by 0.9 and 0.3% in women, 1.1 and 0.9% in men with similar time trends in both rural and urban areas, while smoking prevalence only increased in women by 0.3% per year. A U-shaped association was found between age-adjusted BP and BMI in both sexes and in both areas.

Conclusions

From 2001 to 2009, mean BP, weight and WC significantly increased in the Vietnamese population, leading to an increased prevalence of hypertension and adiposity, suggesting the need for the development of multi-sectoral cost-effective population-based interventions to improve CVD management and prevention. The U-shaped relationship between BP and BMI highlighted the hypertension burden in the underweight population, which is usually neglected in CVD interventions.     

THE TOLERANCE-HYPERBARIC TEST: A CHRONOBIOLOGIC APPROACH FOR IMPROVED DIAGNOSIS OF HYPERTENSION

Blood pressure (BP) displays predictable large-amplitude circadian variability. Thus, the identification and the proper definition of hypertension are highly ambiguous when based on single time-unspecified measurements. One way to deal with such variability in the diagnosis of hypertension is to replace the commonly used constant limits of BP by a time-specified reference interval based on the normal circadian BP rhythm assessed by ambulatory BP monitoring (ABPM). A proper reference limit can be constructed, for instance, as a tolerance interval computed for every specific time interval throughout the 24 h. Once such a threshold (given by the upper limit of the tolerance interval) is constructed, a hyperbaric index (HBI) can be computed by numerical integration of the total area of any given patient's BP profile above threshold. The HBI plus the duration of excess within the 24h day serves as nonparametric endpoints for assessing hypertension. Both retrospective and prospective evaluation of this tolerance-hyperbaric test validate its high sensitivity and specificity in the diagnosis of hypertension. We describe the theory of the HBI as well as a newly created dedicated software program that automatically derives the tolerance intervals from a reference database of normotensive subjects and calculates the HBI and other potentially valuable parameters based on data obtained by ABPM. The establishment of time-qualified tolerance limits and the assessment of the extent and timing of BP elevation represents a valuable tool for the more accurate diagnosis of hypertension as well as means of gauging response to treatment.