Preeclampsia and the risk of end-stage renal disease

Abnormal placentation, angiogenic factors, and the pathogenesis of preeclampsia

Preeclampsia is a common complication of pregnancy with potentially devastating consequences to both the mother and the baby.It is the leading cause of maternal deaths in developing countries. In developed countries it is the major cause of iatrogenic premature delivery and contributes significantly to increasing health care cost associated with prematurity. There is currently no known treatment for preeclampsia; ultimate treatment involves delivery of the placenta. Although there are several risk factors (such as multiple gestation or chronic hypertension), most patients present with no obvious risk factors. The molecular pathogenesis of preeclampsia is just now being elucidated. It has been proposed that abnormal placentation and an imbalance in angiogenic factors lead to the clinical findings and complications seen in preeclampsia. Preeclampsia is characterized by high levels of circulating antiangiogenic factors such as soluble fms-like tyrosine kinase-1 and soluble endoglin, which induce maternal endothelial dysfunction. These soluble factors are altered not only at the time of clinical disease but also several weeks before the onset of clinical signs and symptoms. Many methods of prediction and surveillance have been proposed to identify women who will develop preeclampsia, but studies have been inconclusive. With the recent discovery of the role of angiogenic factors in preeclampsia, novel methods of prediction and diagnosis are being developed to aid obstetricians and midwives in clinical practice. This article discusses the role of angiogenic factors in the pathogenesis, prediction, diagnosis, and possible treatment of preeclampsia.

Vascular Dysfunction in Women With a History of Preeclampsia and Intrauterine Growth Restriction

Background—

Women with a history of placental disease are at increased risk for the future development of vascular disease. It is unknown whether preexisting endothelial dysfunction underlies both the predisposition to placental disease and the later development of vascular disease. The aim of this study was to assess vascular function in postpartum women and to determine whether differences emerged depending on the presentation of placental disease.

Methods and Results—

Women with a history of early-onset preeclampsia (n=15), late-onset preeclampsia (n=9), intrauterine growth restriction without preeclampsia (n=9), and prior normal pregnancy (n=16) were studied 6 to 24 months postpartum. Flow-mediated vasodilatation and flow-independent (glyceryl trinitrate–induced) vasodilatation were studied through the use of high-resolution vascular ultrasound examination of the brachial artery. Arterial stiffness was assessed by pulse-wave analysis (augmentation index). Laboratory assessment included circulating angiogenic factors (vascular endothelial growth factor, soluble fms-like tyrosine kinase 1, placental growth factor, and soluble endoglin). Flow-mediated vasodilatation was significantly reduced in women with previous early-onset preeclampsia and intrauterine growth restriction compared with women with previous late-onset preeclampsia and control subjects (3.2±2.7% and 2.1±1.2% versus 7.9±3.8% and 9.1±3.5%, respectively; P <0.0001). Flow-independent vasodilatation was similar among all groups. Similarly, the radial augmentation index was significantly increased among women with previous early-onset preeclampsia and intrauterine growth restriction, but not among late preeclamptic women and control subjects ( P =0.0105). Circulating angiogenic factors were similar in all groups.

Conclusion—

Only women with a history of early-onset preeclampsia or intrauterine growth restriction without preeclampsia exhibit impaired vascular function, which might explain their predisposition to placental disease and their higher risk of future vascular disease.

Hypertension in pregnancy: a comprehensive update

Hypertensive disorders of pregnancies remain a central public health concern throughout the world, and are a major cause of maternal mortality in the developing world. Although treatment options have not significantly changed in recent years, insight on the pathogenesis of preeclampsia/eclampsia has been remarkable. With improved animal models of preeclampsia and large-scale human trials, we have embarked upon a new era where angiogenic biomarkers based on mechanism of disease can be designed to assist in early diagnosis and treatment. There is also a growing recognition of how elusive the diagnosis of eclampsia can be, especially in the postpartum period. Proper treatment of these patients depends heavily on the correct diagnosis, especially by the emergency physician. Finally, large epidemiologic studies have revealed that preeclampsia, once thought to be a self-limited entity, now appears to portend real damage to the cardiovascular and other organ systems in the long term. This review will present the latest update on our understanding of the various hypertensive disorders of pregnancies and their treatment options.

Risk factors for end-stage renal disease in a community-based population: 26-year follow-up of 25,821 men and women in eastern Finland

BACKGROUND AND OBJECTIVE

There are very few European cohort studies assessing the risk factors of end-stage renal disease (ESRD) in a community-based population. This study investigated the predictors of ESRD in Finland.

DESIGN

Prospective cohort study.

SETTING

Eastern Finland.

SUBJECTS

A random sample of 25,821 men and women aged 25-64 years from the national population register participating in three independent cross-sectional population surveys in 1972, 1977 and 1982. Only the subjects without diagnosis of ESRD or chronic kidney disease based on the national register data were included in the study.

MAIN OUTCOME MEASURE

Initiation of renal replacement therapy (dialysis or kidney transplantation) identified from the Finnish Registry for Kidney Diseases through December 31, 2006.

RESULTS

A total of 94 cases with ESRD were identified during a mean follow-up period of 26.5 years. In a multivariate proportional subdistribution hazard regression analysis, taking into account death as a competing risk event, diabetes (hazard ratio [HR] 4.76, 95% confidence interval [CI] 2.32-9.79), hypertension (HR 2.21, 95% CI 1.19-4.12), obesity defined as body mass index > or =30 kg m(-2) (HR 2.02, 95 %CI 1.10-3.71) and male gender (HR 1.68, 95% CI 1.19-4.12) were independent risk factors for ESRD.

CONCLUSION

The findings of the present study confirm that modifiable risk factors play a major role in the development of ESRD in the North-European population. People with diabetes, hypertension or obesity should be considered as the target groups when planning preventive measures to control the future epidemic of ESRD.

Are adverse pregnancy outcomes risk factors for development of end-stage renal disease in women with diabetes?

BACKGROUND

It is unknown whether adverse pregnancy-related outcomes in women with pregestational diabetes are associated with later development of end-stage renal disease (ESRD) or death.

METHODS

We linked data from the Medical Birth Registry of Norway with data from the Norwegian Renal Registry and the Norwegian Cause of Death Registry. Data from up to three pregnancies for women with a first singleton delivery from 1967 to 1994 were included and analysed in a cohort design using Cox regression.

RESULTS

Altogether, 639,018 women were included in the analyses, among whom 2204 women had diabetes mellitus before pregnancy. Their first pregnancy was complicated by pre-eclampsia in 13.2%, low birth weight offspring (<2.5 kg) in 11.0% and preterm birth in 25.1%, and their risk of ESRD and death in the follow-up period of up to 37 years was markedly higher. In women with pregestational diabetes, pre-eclampsia and preterm birth were associated with significantly increased risks of ESRD and death in women with only one pregnancy, but not in women with two or more pregnancies.

CONCLUSIONS

In women with pregestational diabetes, pre-eclampsia and preterm birth were associated with long-term increased risk of ESRD and death, but only in women who had only one pregnancy.

GLOMERULONEPHRITIS AND THE NEPHROTIC SYNDROME IN PREGNANCY

Glomerulonephritis (GN) may be manifest clinically in several ways. It may be asymptomatic and associated with only minor urinary dipstick abnormalities, GN may present with one of the classic renal nephritic or nephrotic syndromes, or may be associated with progressive chronic kidney disease with hypertension and the gradual development of uraemia, or it may present with fulminating life threatening illness with severe acute kidney injury. The development of GN may indicate a primary renal limited disease, or may be secondary in association with systemic diseases such as systemic lupus erythematosus (SLE), myeloma, infections or diabetes. Although immunological abnormalities underlie the development of many forms of GN, precise pathogenic mechanisms remain unclear and diagnostic labels may simply reflect a description of the glomerular histological changes observed (Table 1).

Pregnancy and chronic kidney disease: a challenge in all CKD stages

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is a challenge for pregnancy. Its recent classification underlines the importance of its early phases. This study's aim was to evaluate outcomes of pregnancy according to CKD stage versus low-risk pregnancies followed in the same center.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The prospective analysis was conducted from January 2000 to May 2009 with the start of observation at referral and end of observation 1 month after delivery. Ninety-one singleton deliveries were studied; 267 "low-risk" singleton pregnancies served as controls. Because of the lack of hard end points (death, start of dialysis), surrogate end points were analyzed (cesarean section, prematurity, neonatal intensive care).

RESULTS

CKD outcome was worse than physiologic pregnancies: preterm delivery (44% versus 5%); cesarean section (44% versus 25%); and need for neonatal intensive care (26% versus 1%). The differences were highly significant in stage 1 CKD (61 cases) versus controls (CKD stage 1: cesarean sections = 57%, preterm delivery = 33%, intensive care = 18%). In CKD, proteinuria and hypertension were correlated with outcomes [proteinuria dichotomized at 1 g/24 h at referral: need for intensive care, relative risk (RR) = 4.16 (1.05 to 16.46); hypertension: preterm delivery, RR = 7.24 (2.30 to 22.79); cesarean section, RR = 5.70 (1.69 to 19.24)]. Statistical significance across stages was reached for preterm delivery [RR = 3.32 (1.09 to 10.13)].

CONCLUSIONS

CKD is a challenge for pregnancy from early stages. Strict follow-up is needed for CKD patients, even when there is normal renal function.

Impact of bariatric surgery on hypertensive disorders in pregnancy: retrospective analysis of insurance claims data

OBJECTIVE

To determine whether women who had a delivery after bariatric surgery have lower rates of hypertensive disorders in pregnancy compared with women who had a delivery before bariatric surgery.

DESIGN

Retrospective cohort study.

SETTING

Claims data for 2002-6 from seven insurance plans in the United States.

PARTICIPANTS

585 women aged 16-45 who had undergone bariatric surgery, had at least one pregnancy and delivery, and had continuous insurance coverage during pregnancy plus two weeks after delivery.

MAIN OUTCOME MEASURE

Hypertensive disorders in pregnancy defined with ICD-9 codes. The independent variable was the timing of delivery in relation to bariatric surgery, classified as deliveries before and after surgery. We used logistic regression to calculate odds ratios and confidence intervals for each type of hypertensive disorder in pregnancy.

RESULTS

Among the 585 women who had undergone bariatric surgery and had a delivery, 269 delivered before surgery and 316 delivered after surgery. Gastric bypass was the surgery in 82% (477) of all women. Women who delivered before surgery were younger at the time of delivery (mean age 31.3 v 32.5) but had higher rates of pre-existing diabetes and gestational diabetes mellitus. Compared with women who delivered before surgery, women who delivered after surgery had substantially lower rates of pre-eclampsia and eclampsia (odds ratio 0.20, 95% confidence interval 0.09 to 0.44), chronic hypertension complicating pregnancy (0.39, 0.20 to 0.74), and gestational hypertension (0.16, 0.07 to 0.37), even after adjustment for age at delivery, multiple pregnancy (that is, twins or more), surgical procedure, pre-existing diabetes, and insurance plan.

CONCLUSION

In this retrospective analysis of US women, bariatric surgery was associated with lower rates of hypertensive disorders in subsequent pregnancy.

Differential expression and distribution of placental glutathione peroxidases 1, 3 and 4 in normal and preeclamptic pregnancy

Preeclampsia is a pregnancy-specific condition affecting 2-7% of women and a leading cause of perinatal and maternal morbidity and mortality; it may also predispose the mother and fetus to increased risks of adult cardiovascular disease. The selenoprotein glutathione peroxidases (GPxs) have critical roles in regulating antioxidant status.

OBJECTIVES, STUDY DESIGN AND MAIN OUTCOME MEASURES

Immunohistochemical measurements of GPx1, GPx3 and GPx4 protein expression were performed on samples taken from three standardised sampling sites between the cord insertion and the periphery of the placenta from 12 normotensive, and 12 preeclamptic women to establish if their expression differed between sampling sites. Total GPx activities were also examined from the three sampling sites of these placentae.

RESULTS

There were highly significant reductions in overall immunohistochemical staining of all 3 GPxs in the preeclampsia compared to normotensive placentae (GPx1: P=0.016; GPx3: P=0.003; GPx4: P<0.001). Furthermore, graded differences in expression between the standardised placental sampling sites were also found for GPx3 (higher in the inner region, P=0.05) and GPx4 (higher in the periphery, P=0.02) but not GPx1. Placental GPx enzyme activity was also significantly reduced in tissue from preeclamptic women as compared to normotensive women (P=0.007; the difference was more pronounced nearest the cord insertion).

CONCLUSIONS

We have shown highly significant reductions in expression of all three major classes of GPx in placentae from women with preeclampsia, and distribution gradients in activity, which may relate to the differential oxygenation of regions of the placenta.

The clinical importance of nephron mass

Abundant evidence supports the association between low birth weight (LBW) and renal dysfunction in humans. Anatomic measurements of infants, children, and adults show significant inverse correlation between LBW and nephron number. Nephron numbers are also lower in individuals with hypertension compared with normotension among white and Australian Aboriginal populations. The relationship between nephron number and hypertension among black individuals is still unclear, although the high incidence of LBW predicts low nephron number in this population as well. LBW, a surrogate for low nephron number, also associates with increasing BP from childhood to adulthood and increasing risk for chronic kidney disease in later life. Because nephron numbers can be counted only postmortem, surrogate markers such as birth weight, prematurity, adult height, reduced renal size, and glomerulomegaly are potentially useful for risk stratification, for example, during living-donor assessment. Because early postnatal growth also affects subsequent risk for higher BP or reduced renal function, postnatal nutrition, a potentially modifiable factor, in addition to intrauterine effects, has significant influence on long-term cardiovascular and renal health.

Hypertension during pregnancy is associated with coronary artery calcium independent of renal function

BACKGROUND

Hypertension during pregnancy (HDP) increases the risk of future coronary heart disease (CHD), but it is unknown whether this association is mediated by renal injury. Reduced renal function is both a complication of HDP and a risk factor for CHD.

METHODS

Logistic regression models were fit to examine the association between a history of HDP and the presence and extent of coronary artery calcification (CAC), a measure of subclinical coronary artery atherosclerosis, in 498 women from the Epidemiology of Coronary Artery Calcification Study (mean age 63.3 +/- 9.3 years).

RESULTS

Fifty-two (10.4%) women reported a history of HDP. After adjusting for age at time of study participation, HDP was associated with increased serum creatinine later in life (p = 0.014). HDP was positively associated with the presence of CAC after adjusting for age at time of study participation (OR = 2.7, 95% CI 1.4-5.4). This association was slightly attenuated with adjustment for body size and blood pressure (OR = 2.4, 95% CI 1.2-4.9) but was not further attenuated with adjustment for serum creatinine and urinary albumin/creatinine ratio (OR = 2.6, 95% CI 1.3-5.3). Results were similar for CAC extent.

CONCLUSIONS

HDP may increase a woman's risk of future CHD beyond traditional risk factors and renal function. Women with a history of HDP should be monitored for potential increased risk of CHD as they age.

PROTEINURIA IN PREECLAMPSIA: FROM BENCH TO BEDSIDE

Pre-eclampsia (PE) remains the leading cause of maternal and fetal mortality in the developed world and parts of the developing world. Morbidity and mortality from PE is increased in the developing world compared to the developed world, as availability and access to antenatal care and pathology services are limited.

Pre-eclampsia, soluble fms-like tyrosine kinase 1, and the risk of reduced thyroid function: nested case-control and population based study

OBJECTIVE

To determine if pre-eclampsia is associated with reduced thyroid function during and after pregnancy.

DESIGN

Nested case-control study during pregnancy and population based follow-up study after pregnancy.

SETTING

Calcium for Pre-eclampsia Prevention trial of healthy pregnant nulliparous women in the United States during 1992-5, and a Norwegian population based study (Nord-Trondelag Health Study or HUNT-2) during 1995-7 with linkage to the medical birth registry of Norway.

PARTICIPANTS

All 141 women (cases) in the Calcium for Pre-eclampsia Prevention trial with serum measurements before 21 weeks' gestation (baseline) and after onset of pre-eclampsia (before delivery), 141 normotensive controls with serum measurements at similar gestational ages, and 7121 women in the Nord-Trondelag Health Study whose first birth had occurred in 1967 or later and in whom serum levels of thyroid stimulating hormone had been subsequently measured.

MAIN OUTCOME MEASURES

Thyroid function tests and human chorionic gonadotrophin and soluble fms-like tyrosine kinase 1 concentrations in the Calcium for Pre-eclampsia Prevention cohort and odds ratios for levels of thyroid stimulating hormone above the reference range, according to pre-eclampsia status in singleton pregnancies before the Nord-Trondelag Health Study.

RESULTS

In predelivery specimens of the Calcium for Pre-eclampsia Prevention cohort after the onset of pre-eclampsia, thyroid stimulating hormone levels increased 2.42 times above baseline compared with a 1.48 times increase in controls. The ratio of the predelivery to baseline ratio of cases to that of the controls was 1.64 (95% confidence interval 1.29 to 2.08). Free triiodothyronine decreased more in the women with pre-eclampsia than in the controls (case ratio to control ratio 0.96, 95% confidence interval 0.92 to 0.99). The predelivery specimens but not baseline samples from women with pre-eclampsia were significantly more likely than those from controls to have concentrations of thyroid stimulating hormone above the reference range (adjusted odds ratio 2.2, 95% confidence interval 1.1 to 4.4). Both in women who developed pre-eclampsia and in normotensive controls the increase in thyroid stimulating hormone concentration between baseline and predelivery specimens was strongly associated with increasing quarters of predelivery soluble fms-like tyrosine kinase 1 (P for trend 0.002 and <0.001, respectively). In the Nord-Trondelag Health Study, women with a history of pre-eclampsia in their first pregnancy were more likely than other women (adjusted odds ratio 1.7, 95% confidence interval 1.1 to 2.5) to have concentrations of thyroid stimulating hormone above the reference range (>3.5 mIU/l). In particular, they were more likely to have high concentrations of thyroid stimulating hormone without thyroid peroxidase antibodies (adjusted odds ratio 2.6, 95% confidence interval 1.3 to 5.0), suggesting hypothyroid function in the absence of an autoimmune process. This association was especially strong (5.8, 1.3 to 25.5) if pre-eclampsia had occurred in both the first and the second pregnancies.

CONCLUSION

Increased serum concentration of soluble fms-like tyrosine kinase 1 during pre-eclampsia is associated with subclinical hypothyroidism during pregnancy. Pre-eclampsia may also predispose to reduced thyroid function in later years.

Insulin resistance in women's health: why it matters and how to identify it

PURPOSE OF REVIEW

To examine the significance of insulin resistance in women's health and review methods for diagnosing it.

RECENT FINDINGS

Clinical phenotypes in conjunction with standard clinical biochemical assays, that is, the metabolic syndrome, remain the key method to diagnose insulin resistance in clinical practice. Candidate alleles from type 2 diabetes offer little predictive value for cardiovascular events beyond traditional risk factors. Simple environmental factors such as irregular meal frequency appear to increase the risk of the metabolic syndrome and require greater scrutiny. Pregnancy complications, particularly gestational diabetes and preeclampsia in the mother and preterm birth in the fetus are events that suggest elevated risk for future cardiovascular morbidity in those affected.

SUMMARY

Clinical phenotypes of insulin resistance identify women at risk for perinatal and reproductive complications.

Preeclampsia: the role of angiogenic factors in its pathogenesis

Preeclampsia, a systemic syndrome of pregnancy clinically characterized by new onset of proteinuria and hypertension, is associated with significant morbidity and mortality to both mothers and fetuses. The pathogenesis of preeclampsia has been enigmatic; this review will focus on understanding the origins of this disorder. Preeclampsia originates in the placenta, starting with inadequate cytotrophoblast invasion and ending with widespread maternal endothelial dysfunction. Production of placental anti-angiogenic factors, specifically soluble fms-related tyrosine kinase 1 and soluble endoglin, have been shown to be upregulated in preeclampsia. These placental anti-angiogenic factors are released into the maternal circulation; their actions disrupt the maternal endothelium and result in hypertension, proteinuria, and the other systemic manifestations of preeclampsia. The molecular basis for placental dysregulation of these pathogenic factors remains unknown, remains unknown. Hypoxia is likely an important regulator. Other factors such as alterations in the renin-angiotensin-aldosterone axis, immune maladaption, excessive shedding of trophoblast debris, oxidative stress, and genetic factors likely contribute to the pathogenesis of the abnormal placentation. As of 2009, the only successful treatment for preeclampsia is delivery. No definitive preventive strategies have been identified. However, several of the recent observations related to phenotypic causality provide stimuli for the development of novel therapies.

Placental ischemia and breast cancer risk after preeclampsia: tying the knot

Although hypertensive disorders of pregnancy, such as preeclampsia, continue to be a significant source of maternal and fetal morbidity and mortality, there is emerging evidence that effects of the preeclamptic syndrome persist into later life. In contrast to recent studies that have reported that formerly preeclamptic women are at increased risk for cardiovascular disease, it appears that preeclampsia may be associated with a decreased risk of breast cancer. Recent investigations have provided exciting new insights into potential mechanisms underlying the pathogenesis of preeclampsia and some of these findings may bear relevance to the anticancer effects reported in the epidemiological literature. Placental ischemia is regarded to be a primary factor in preeclampsia and the ischemic placenta produces a variety of factors that generate profound effects on endothelial cell function and the cardiovascular system during pregnancy. Moreover, several of these factors are reportedly elevated many years after preeclamptic pregnancies. This group of molecules includes factors such as soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin/CD105 (sEng) and various cytokines. Many of these factors have been strongly associated with cancer incidence and, hence, could contribute to the modification of cancer risk observed in these women. Therefore, identifying potential connections between placental dysfunction and future cancer risk is an important endeavor towards realizing novel therapeutic regimens for cancer patients.

Gadd45a stress signaling regulates sFlt-1 expression in preeclampsia

Preeclampsia, which affects approximately 5-8% of all pregnancies and is one of the leading causes of maternal and fetal morbidity and mortality, is a pregnancy induced complex of multiple pathological changes, including elevated blood pressure, proteinuria and edema manifested after 20 weeks gestation. There is growing evidence that placental stresses during pregnancy, notably hypoxia, and an increase in circulating soluble Flt-1 (sFlt-1) are important in the etiopathogenesis of preeclampsia. How placental stress results in elevated sFlt-1 expression is currently unknown. Here we provide novel data implicating the Gadd45a stress sensor protein as an upstream modulator of pathophysiological changes observed in preeclampsia. It is shown that Gadd45a expression and activation of its downstream effector p38 kinase are elevated in preeclamptic placentas compared to non-preeclamptic controls, and correlate with elevated sFlt-1. Furthermore, a regulatory loop is demonstrated where stress, including hypoxia, IL-6 or hypertonic stress, caused induction of Gadd45a, leading to p38 activation and ultimately increasing sFlt-1 secretion in endothelial cells. These data provide a compelling working frame to further test the role of Gadd45 stress sensors in the etiology of preeclampsia, and set the stage for considering novel therapeutic regimens, including p38 inhibitors, for treatment of preeclampsia.

Kidney function and future risk for adverse pregnancy outcomes: a population-based study from HUNT II, Norway

BACKGROUND

Current knowledge on prepregnancy reduced kidney function and the risk of adverse pregnancy outcomes mainly relies on small studies in selected populations. We aim to investigate whether reduced kidney function is associated with the risk of adverse pregnancy-related outcomes in the general population.

METHODS

A population-based study linking all women attending the Second Health Study in Nord-Trøndelag, Norway (1995-97) and subsequent pregnancies registered in the Medical Birth Registry. Multivariable random-effect logistic regression analysis was used to explore the association between renal function and study outcome.

RESULTS

The mean eGFR among 3405 women was 107.6 +/- 19.4 ml/min/1.73 m(2) at baseline; 18.8% and 0.1% had eGFR of 60-89 and <60, respectively. Over the next 11 years, they gave birth to 5655 singletons of whom 885 (17.7%) were complicated with preeclampsia, small for gestational age (SGA) or preterm birth. Women with eGFR 60-89 were not at increased risk for this combined outcome compared to women with eGFR > or =90, although women with eGFR 60-74 tended to have an increased risk. Neither was reduced kidney function a risk factor among women with microalbuminuria, but those with an eGFR of 60-89 plus hypertension had a significantly increased risk: odds ratios for preeclampsia, SGA or preterm birth were 2.58 (95% CI 1.40-4.75, P < 0.001) and 10.09 (95% CI 2.38-42.87, P < 0.001) in hypertensive women with eGFR 75-89 and 60-74, respectively. Relative excess risk due to interaction between reduced kidney function and hypertension was 2.23 (95% CI 1.35-3.10, P < 0.001). Women with a reduced kidney function were not at increased risk for other pregnancy complications like caesarean section, maternal bleeding, dystocia, pre-labour rupture of membranes, Apgar score < or =7, stillbirth or congenital malformations.

CONCLUSIONS

Women with eGFR 60-89 ml/min/1.73 m(2) were not at increased risk for preeclampsia, SGA or preterm birth unless they were also hypertensive.

Prehypertension, obesity, and risk of kidney disease: 20-year follow-up of the HUNT I study in Norway

BACKGROUND

The combined effect of blood pressure (BP) and body weight on risk of kidney disease has not been previously studied. To improve risk stratification in prehypertensive individuals (ie, BP, 120 to 139/80 to 89 mm Hg), we examined the interaction between BP and body weight on the risk of end-stage renal disease or chronic kidney disease (CKD)-related death.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

74,986 adults participating in the first Health Study in Nord-Trøndelag (88% participation rate) were linked to the Norwegian Renal Registry and Cause of Death Registry.

PREDICTORS

BP and body weight were measured by using standard procedures, and other relevant covariates were obtained from an extensive questionnaire.

OUTCOME & MEASUREMENTS

Hazard ratios for treated end-stage renal disease and CKD-related death were calculated.

RESULTS

Mean systolic BP and body mass index (BMI) were 136.8 +/- 23.3 (SD) mm Hg and 25.2 +/- 3.9 kg/m(2), whereas 12.9% had treated hypertension at baseline, respectively. During a median follow-up of 21 years (1,345,882 person-years), 507 men (1.4%) and 319 women (0.8%) initiated renal replacement therapy (n = 157) or died of CKD (n = 669). Multiadjusted risk of these kidney outcomes increased continuously with no lower threshold for BP. The risk associated with body weight started to increase from a BMI of 25.0 kg/m(2). In participants with BP less than 120/80 mm Hg, risk did not increase with increasing BMI. In prehypertensive participants, multivariate adjusted hazard ratios in the BMI categories 18.5 to 24.9, 25.0 to 29.9, 30.0 to 34.9, and 35.0 kg/m(2) or greater were 1.21 (95% confidence interval [CI], 0.67 to 2.17), 1.10 (95% CI, 59 to 2.00), 2.66 (95% CI, 1.28 to 5.53), and 5.94 (95% CI, 1.94 to 18.20) compared with BP less than 120/80 mm Hg and BMI of 18.5 to 24.9 kg/m(2), respectively (P = 0.02 for trend). Corresponding risks in hypertensive participants were 2.13 (95% CI, 1.23 to 3.70), 2.40 (95% CI, 1.40 to 4.15), 3.32 (95% CI, 1.89 to 5.81), and 5.53 (95% CI, 3.01 to 10.20), respectively (P < 0.001 for trend).

LIMITATIONS

Baseline creatinine measurements were not available; hence, a secondary analysis was performed that excluded all individuals who experienced outcomes in the 5 years after the study start.

CONCLUSIONS

Participants with prehypertension are not at increased risk of serious kidney outcomes if BMI is less than 30.0 kg/m(2). However, the risk of kidney disease increases substantially if prehypertension is present in obese participants.

Sexual dimorphism in the aging kidney: differences in the nitric oxide system

Females-both rats and women-are substantially protected against the age-dependent decrease in renal function that occurs in males of the species. In part, this finding reflects the cardioprotective and renoprotective effects of estrogens, but estrogen has multiple actions, not all of which are beneficial. In addition, the low androgen level in women might be protective against a decline in renal function, but animal and clinical data on possible adverse effects of androgens are controversial. Androgens also have multiple actions, one of which-aromatization to estrogen-is likely to be protective. Sex steroids clearly have many complex actions, which explains the conflicting information on their relative benefits and dangers. Endothelial nitric oxide (NO) deficiency contributes importantly to cardiovascular risk and intrarenal NO deficiency is clearly linked to chronic kidney disease progression in animal models. Endothelial dysfunction develops with increasing age but is delayed in females, correlating with a delayed rise in asymmetric dimethylarginine level. There is no clear link between aging and arginine (the NO synthase substrate) deficiency. Animal data suggest that the aging kidney develops NO deficiency as a result of changes in neuronal NO synthase. The increased oxidative stress that occurs with aging affects multiple stages of the NO biosynthetic pathway and results in decreased production and/or action of NO. NO production is better preserved in females than in males, partly as a result of the actions of estrogens.

Pregnancy outcomes after kidney donation

The outcome of pregnancy in kidney donors has generally been viewed to be favorable. We determined fetal and maternal outcomes in a large cohort of kidney donors. A total of 2102 women have donated a kidney at our institution; 1589 donors responded to our pregnancy surveys; 1085 reported 3213 pregnancies and 504 reported none. Fetal and maternal outcomes in postdonation pregnancies were comparable to published rates in the general population. Postdonation (vs. predonation) pregnancies were associated with a lower likelihood of full-term deliveries (73.7% vs. 84.6%, p = 0.0004) and a higher likelihood of fetal loss (19.2% vs. 11.3%, p < 0.0001). Postdonation pregnancies were also associated with a higher risk of gestational diabetes (2.7% vs. 0.7%, p = 0.0001), gestational hypertension (5.7% vs. 0.6%, p < 0.0001), proteinuria (4.3% vs. 1.1%, p < 0.0001) and preeclampsia (5.5% vs. 0.8%, p < 0.0001). Women who had both pre- and post-donation pregnancies were also more likely to have these adverse maternal outcomes in their postdonation pregnancies. In this large survey of previous living donors in a single center, fetal and maternal outcomes and pregnancy outcomes after kidney donation were similar to those reported in the general population, but inferior to predonation pregnancy outcomes.

Placental ischemia and cardiovascular dysfunction in preeclampsia and beyond: making the connections

Hypertensive disorders of pregnancy continue to be a significant source of maternal and fetal morbidity and mortality, and recent evidence suggests that the incidence of preeclampsia (PE) is increasing. Recent epidemiological studies indicate that the effects of PE may persist long after pregnancy, in both the mother and the offspring, as increased incidence of cardiovascular disease. The last decade has produced new insights into the pathogenesis of PE. The initiating event in PE appears to be impaired placental perfusion and subsequent placental ischemia, which results in the elaboration of numerous factors. Factors such as soluble fms-like tyrosine kinase-1, soluble endoglin and the angiotensin II type-1 receptor autoantibodies contribute to maternal endothelial and cardiovascular dysfunction, marked by increased reactive oxygen species and decreased bioavailable VEGF, nitric oxide and prostacyclin. However, the importance of the various endothelial and humoral factors that mediate these changes during PE remain to be elucidated.