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Endocrinology, Diabetes and Hypertension Division (E.W.S.) and Divisions of General Medicine and Womens Health (C.G.S.), Department of Medicine, Brigham and Womens Hospital, Harvard Medical School, Boston, Massachusetts 02115
Address all correspondence and requests for reprints to: Ellen W. Seely, M.D., Endocrine, Diabetes, and Hypertension Division, Brigham and Womens Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, Massachusetts 02115.
| Abstract |
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, tissue plasminogen activator, plasminogen activator inhibitor-1, and testosterone. The documentation of these features before the onset of hypertension in pregnancy suggests that insulin resistance or associated abnormalities may have a role in this disorder. Furthermore, the recognition that features of the insulin resistance syndrome persist many years after pregnancy among women with this condition raises the possibility that these women may have increased risk for future cardiovascular disease. These observations suggest that interventions to reduce insulin resistance may reduce the risk of both hypertension in pregnancy and later life cardiovascular complications, and warrant further study. | Introduction |
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| Classification of hypertensive disorders of pregnancy |
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| Potential causes |
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Some data have suggested that abnormalities of the placenta are the primary cause of preeclampsia. However, the observations that several metabolic abnormalities predispose to the development of preeclampsia, and that these abnormalities are also observed in the nonpregnant state in women who have had preeclampsia, suggest that features of the mother must also be considered.
All cases of de novo hypertension in pregnancy are unlikely to be attributable to a single cause. Rather, different etiologies may lead to the same phenotype in different women. Here we focus on the potential role of insulin resistance and associated abnormalities as pathogenic factors for the development of hypertensive pregnancy and its complications. The insulin resistance syndrome provides a plausible link between hypertensive pregnancy and many of its risk factors and sequelae in both pregnancy and later life.
| Insulin resistance and cardiovascular risk outside of pregnancy |
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, C-reactive protein (CRP), and cellular adhesion molecules (2, 3). Other endocrine correlates of insulin resistance in women include elevated androgen levels and reduced levels of SHBG (4). | Insulin resistance and normal pregnancy |
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increase as normal pregnancy and associated insulin resistance progress (6, 7, 8). Levels of CRP are slightly elevated in normal pregnancy, but unlike the other markers noted, do not increase serially with advancing gestation (9). | Hypertensive pregnancy |
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In women whose pregnancies are complicated by hypertension, there appears to be an exaggeration of insulin resistance and associated metabolic changes (Table 2
). Although it remains uncertain to what extent these factors are pathogenic in hypertensive pregnancy, the available data suggest that some may play a role in disease evolution, whereas others may be markers of the underlying disease process. Exaggerated hyperinsulinemia relative to normal pregnancy is well described in women with established preeclampsia (10, 11) or gestational hypertension (10). Studies more directly assessing insulin resistance have also suggested differences between women with de novo hypertension in pregnancy and normotensive women. In a small study using the euglycemic clamp technique, insulin resistance was greatest in women with gestational hypertension, whereas results were similar in women with normotensive pregnancy and women with preeclampsia (12). A recent study using minimal model analysis (13) yielded comparable results, although in another report using this method, women with preeclampsia were more insulin resistant than normotensive controls (14). These seemingly discrepant observations may be explained by small sample sizes, diagnostic misclassification, and/or the likely multifactorial nature of this condition.
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Obesity and physical inactivity, two factors closely associated with insulin resistance, are also predictive of hypertensive pregnancy. A higher body mass index before pregnancy or early in pregnancy is associated with increased risk for both preeclampsia and gestational hypertension (17, 18, 21, 22, 23). Furthermore, greater gestational weight gain has also predicted risk for preeclampsia (17) or gestational hypertension (23), as has higher waist circumference (a measure of central adiposity) between 6 and 16 wk (22). In contrast, increased participation in leisure time physical activity in the first 20 wk of pregnancy has been associated with reduced risk (24). Although these observations are consistent with a role for insulin resistance in hypertensive pregnancy, it is also possible that other factors, such as diet composition, may explain the observed associations.
Furthermore, some studies (16, 25) suggest that gestational diabetes (which itself is associated with underlying insulin resistance) is a risk factor for the development of hypertensive pregnancy. This association persists even after adjusting for obesity and maternal age (26).
Lipids.
In women with established preeclampsia, triglyceride (6, 13, 14) and free fatty acid levels (14, 27) have been reported to be higher and high density lipoprotein cholesterol levels lower (6, 14) than those in women with normotensive pregnancy. Other investigators have documented these abnormalities only in women with gestational hypertension (12). Studies have reported an increased proportion of small dense LDL particles in women with established preeclampsia (6, 7).
Similar to hyperinsulinemia, elevated total cholesterol levels (18, 28) have been reported to antedate the development of either preeclampsia or gestational hypertension. Elevated triglyceride (29, 30) and free fatty acid levels (29) during pregnancy have similarly preceded the development of preeclampsia specifically, as have lower levels of high density lipoprotein cholesterol (30).
Oxidized lipids may impair endothelial function directly or indirectly by effects on prostaglandins, including increasing synthesis of thromboxane and inhibiting synthesis of prostacyclin (31). Increases in small dense LDL and triglycerides may also contribute to impaired endothelial function.
Leptin.
Some data suggest that leptin levels are elevated in women with established preeclampsia (32, 33, 34), although not in women with gestational hypertension (34) Leptin levels as early as 20 wk gestation were reported to predict the development of preeclampsia in a high risk population (30).
Increased leptin levels may in part reflect maternal adiposity and have also been hypothesized to reflect placental insufficiency. Leptin might also contribute to endothelial dysfunction by increasing free fatty acid oxidation (35).
TNF
, CRP, and VCAM.
Elevations in TNF
(36, 37, 38) or its receptor (38) have been reported in women with established preeclampsia compared with normotensive controls in several studies, although some data are inconsistent (39). Elevated TNF
levels in the early third trimester (40) may predict the development of preeclampsia, although levels measured earlier have generally not been predictive (40, 41). In small studies polymorphisms in the TNF
gene have been associated with preeclampsia (42, 43). Another inflammatory marker, CRP, was not predictive of preeclampsia (41).
TNF
may promote hypercoagulability and increased lipolysis, with resulting impairment of endothelial relaxation. TNF
also causes the release of VCAM-1, elevations of which have been reported in established preeclampsia (38, 44), although not before its development (45).
PAI-1 and TPA Ag.
Women with established preeclampsia have higher levels of TPA Ag than normotensive pregnant women, and elevations are proportional to the magnitude of proteinuria (46). PAI-1 is likewise elevated in established preeclampsia and is higher in more severe disease (47). Among women at high risk for preeclampsia, the ratio of PAI-1 to PAI-2 (the latter primarily produced by the placenta) was increased before the development of disease (30). Increased PAI-1 may reflect impaired fibrinolytic function, which might predispose to the coagulopathy associated with preeclampsia.
Testosterone and SHBG.
Cross-sectional data indicate higher levels of total and free testosterone, but comparable levels of SHBG, in women with established preeclampsia compared with normotensive women; differences were not explained by body mass index (48). In a prospective study, although neither total nor free testosterone in the first trimester predicted later development of preeclampsia, lower levels of SHBG were predictive (4). Polycystic ovary syndrome, which is associated with insulin resistance, elevated testosterone, and low SHBG levels, has been linked to increased risk for pregnancy-induced hypertension even in the absence of associated obesity (49). Elevated androgen levels may be explained at least in part by increases in inhibin A, which have also been described in women with preeclampsia (50).
In animal models, androgens increase vasoconstriction in response to pressors (51). Androgens also affect the prostaglandin balance to decrease the synthesis of prostacyclin (52), leading to increased platelet aggregation. Both of these abnormalities are characteristic of preeclampsia.
| Postpartum findings in women with a history of new-onset hypertension in pregnancy |
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In several studies conducted postpartum, women with a history of preeclampsia have been shown to be insulin resistant, as demonstrated by elevated fasting insulin and glucose levels (53) (at 6 months to 2 yr postpartum), greater insulin response to oral glucose tolerance testing (54, 55) (at 8 wk and as late as 17 yr postpartum), or decreased glucose disposal by minimal model analysis (14) (on average at 12 wk postpartum) compared with women with normotensive pregnancy. Other components of the metabolic syndrome that have been reported postpartum among women with prior preeclampsia include elevated triglyceride levels and higher uric acid levels (53). Total cholesterol and very low density lipoprotein levels were also demonstrated to be elevated 25 yr after preeclamptic pregnancy (56), and elevated testosterone levels were found 17 yr after preeclamptic pregnancy (57), compared with levels after uncomplicated pregnancy. Abnormal brachial artery flow mediated (endothelium-dependent) dilatation has also been described in women studied a median of 3 yr after a pregnancy complicated by preeclampsia as compared to women with normotensive pregnancy, even after adjustment for body mass index and other potential confounders (58). These and other similar findings (56) suggest that endothelial dysfunction in preeclampsia is an underlying characteristic of affected women.
| Later life risks |
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Although some earlier studies suggested no increase in future risk of hypertension among women who had preeclampsia or eclampsia (59, 60), the recognition that hypertensive pregnancy is associated with features of the insulin resistance syndrome has resulted in renewed interest in long-term sequelae of this condition. In a large study comparing women with severe preeclampsia or eclampsia to women with uncomplicated pregnancy, the risk for hypertension was increased almost 3-fold at 224 yr of follow-up; the magnitude of risk was correlated with the length of follow-up and was higher among women who had recurrent preeclampsia in their second pregnancy (61). Likewise, blood pressure was higher in women with preeclampsia on average 17 yr after pregnancy than among women who had uncomplicated pregnancy, despite similar body mass indexes in the two groups (55).
Similar to hypertension, the risk of other cardiovascular diseases may also be increased in women with prior preeclampsia, although studies of cardiovascular risk are likewise limited by the difficulty in ruling out essential hypertension misdiagnosed as preeclampsia. In a study of Norwegian women (62), mortality due to cardiovascular causes was increased among women who had preeclampsia and preterm delivery (considered a proxy for severity of preeclampsia) compared with preeclamptic women who delivered at term or women with preterm delivery alone. In another report, women who had a prior discharge diagnosis of preeclampsia were twice as likely as women with uncomplicated pregnancy to be admitted to the hospital for or die from ischemic heart disease (63).
| Clinical implications |
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Women who have had preeclampsia in one pregnancy are at increased risk in subsequent pregnancies. Thus, lifestyle interventions may be particularly relevant to reducing future preeclamptic pregnancy among these women, and studies are particularly warranted in this population.
Even beyond reproductive years, a history of hypertensive pregnancy may have important implications for medical care. The observations of increased prevalence of hypertension and other cardiovascular disease many years after a pregnancy complicated by de novo hypertension suggests that this pregnancy complication might reasonably be viewed as another cardiovascular risk factor in women. In other words, the hormonal milieu of normal pregnancy may cause women with underlying insulin resistance to manifest transient hypertension, which would otherwise not be evident until later in life (64).
Asking women about a history of hypertension in pregnancy may be useful in stratifying future cardiovascular risk, although more data are needed to assess to what extent the risk associated with this condition is independent of obesity and other well established predictors of cardiovascular disease. In women who have had hypertensive pregnancy, attention to cardiovascular risk factors and counseling regarding weight control, diet, and exercise may be particularly important.
| Future directions |
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| Footnotes |
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Abbreviations: CRP, C-reactive protein; LDL, low density lipoprotein; PAI-1, plasminogen activator inhibitor-1; TPA Ag, tissue plasminogen activator antigen; VCAM, vascular cell adhesion molecule.
Received February 13, 2003.
Accepted March 18, 2003.
| References |
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release in preeclampsia. Acta Obstet Gynecol Scand 81:713719[CrossRef][Medline]
(TNF-
) in preeclampsia. Eur J Obstet Gynecol Reprod Biol 100:143145[CrossRef][Medline]
(TNF-
) gene polymorphism expression in preeclampsia. Clin Exp Immunol 104:154159[CrossRef][Medline]
gene in women with preeclampsia. J Assist Reprod Gen 19:220223[CrossRef][Medline]
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