Changes of plasma lipoprotein(a) during and after normal pregnancy in Caucasians

Dyslipidemia management in women of reproductive potential: An Expert Clinical Consensus from the National Lipid Association

Cardiovascular disease (CVD) is the leading cause of death among women and its incidence has been increasing recently, particularly among younger women. Across major professional society guidelines, dyslipidemia management remains a central tenet for atherosclerotic CVD prevention for both women and men. Despite this, women, particularly young women, who are candidates for statin therapy are less likely to be treated and less likely to achieve their recommended therapeutic objectives for low-density lipoprotein cholesterol (LDL-C) levels. Elevated LDL-C and triglycerides are the two most common dyslipidemias that should be addressed during pregnancy due to the increased risk for adverse pregnancy outcomes, such as preeclampsia, gestational diabetes mellitus, and pre-term delivery, as well as pancreatitis in the presence of severe hypertriglyceridemia. In this National Lipid Association Expert Clinical Consensus, we review the roles of nutrition, physical activity, and pharmacotherapy as strategies to address elevated levels of LDL-C and/or triglycerides among women of reproductive age. We include a special focus on points to consider during the shared decision-making discussion regarding pharmacotherapy for dyslipidemia during preconception planning, pregnancy, and lactation.

Oxidized phospholipids in cardiovascular disease

Prolonged or excessive exposure to oxidized phospholipids (OxPLs) generates chronic inflammation. OxPLs are present in atherosclerotic lesions and can be detected in plasma on apolipoprotein B (apoB)-containing lipoproteins. When initially conceptualized, OxPL-apoB measurement in plasma was expected to reflect the concentration of minimally oxidized LDL, but, surprisingly, it correlated more strongly with plasma lipoprotein(a) (Lp(a)) levels. Indeed, experimental and clinical studies show that Lp(a) particles carry the largest fraction of OxPLs among apoB-containing lipoproteins. Plasma OxPL-apoB levels provide diagnostic information on the presence and extent of atherosclerosis and improve the prognostication of peripheral artery disease and first and recurrent myocardial infarction and stroke. The addition of OxPL-apoB measurements to traditional cardiovascular risk factors improves risk reclassification, particularly in patients in intermediate risk categories, for whom improving decision-making is most impactful. Moreover, plasma OxPL-apoB levels predict cardiovascular events with similar or greater accuracy than plasma Lp(a) levels, probably because this measurement reflects both the genetics of elevated Lp(a) levels and the generalized or localized oxidation that modifies apoB-containing lipoproteins and leads to inflammation. Plasma OxPL-apoB levels are reduced by Lp(a)-lowering therapy with antisense oligonucleotides and by lipoprotein apheresis, niacin therapy and bariatric surgery. In this Review, we discuss the role of role OxPLs in the pathophysiology of atherosclerosis and Lp(a) atherogenicity, and the use of OxPL-apoB measurement for improving prognosis, risk reclassification and therapeutic interventions.

Lipid-Lowering Therapy in Woman of Childbearing Age: a Review and Stepwise Clinical Approach

PURPOSE OF REVIEW

Women are less often recognized to have cardiovascular disease (CVD) risk and are underrepresented in randomized trials of lipid-lowering therapy. Here, we summarize non-pharmacologic and pharmacologic strategies for lipid-lowering in women of childbearing age, lipid changes during pregnancy and lactation, discuss sex-specific outcomes in currently available literature, and discuss future areas of research.

RECENT FINDINGS

While lifestyle interventions form the backbone of CVD prevention, some women of reproductive age have an indication for pharmacologic lipid-lowering. Sex-based evidence is limited but suggests that both statin and non-statin lipid-lowering agents are beneficial regardless of sex, especially at high cardiovascular risk. Pharmacologic lipid-lowering therapies, both during the pregnancy period and during lactation, have historically been and continue to be limited by safety concerns. This oftentimes limits lipid-lowering options in women of childbearing age. In this review, we summarize lipid-lowering strategies in women of childbearing age and the impact of therapies during pregnancy and lactation. The limited sex-specific data regarding efficacy, adverse events, and cardiovascular outcomes underscore the need for a greater representation of women in randomized controlled trials. More data on lipid-lowering teratogenicity are needed, and through increased clinician awareness and reporting to incidental exposure registries, more data can be harvested.

Cardiometabolic Profiles in Women with a History of Hypertensive and Normotensive Fetal Growth Restriction

Background: The majority of evidence on associations between pregnancy complications and future maternal disease focuses on hypertensive (Ht) complications. We hypothesize that impaired cardiometabolic health after pregnancies complicated by severe fetal growth restriction (FGR) is independent of the co-occurrence of hypertension. Materials and Methods: In a prospective cohort of women with a pregnancy complicated by early FGR (delivery <34 weeks gestation), with or without concomitant hypertension, cardiometabolic risk factors were assessed after delivery. A population-based reference cohort was used for comparison, and analyses were adjusted for age, current body mass index (BMI), smoking habits, and hormonal contraceptive use. Results: Median time from delivery to assessment was 4 months in both the Ht (N = 115) and normotensive (Nt) (N = 42) FGR groups. Compared with the reference group (N = 380), in both FGR groups lipid profile and glucose homeostasis at assessment were unfavorable. Women with Ht-FGR had the least favorable cardiometabolic profile, with higher prevalence ratios (PRs) for diastolic blood pressure >85 mmHg (PR 4.0, 95% confidence interval [CI] 2.1-6.7), fasting glucose levels >5.6 mmol/L (PR 2.9, 95% CI 1.4-5.6), and total cholesterol levels >6.21 mmol/L (PR 4.5, 95% CI 1.9-8.8), compared with the reference group. Women with Nt-FGR more often had a BMI >30 kg/m² (PR 2.5, 95% CI 1.2-4.7) and high-density lipoprotein-cholesterol levels <1.29 mmol/L (PR 2.4, 95% CI 1.4-3.5), compared with the reference group. Conclusions: Women with a history of FGR showed unfavorable short-term cardiometabolic profiles in comparison with a reference group, independent of the co-occurrence of hypertension. Therefore, women with a history of FGR may benefit from cardiovascular risk factor assessment and subsequent risk reduction strategies.

Maternal cholesterol levels during gestation: boon or bane for the offspring?

An increase in cholesterol levels is perceived during pregnancy and is considered as a normal adaptive response to the development of the fetus. In some pregnancies, excessive increase in total cholesterol with high levels of Low-Density Lipoprotein leads to maladaptation by the fetus to cholesterol demands, resulting in a pathological condition termed as maternal hypercholesterolemia (MH). MH is considered clinically irrelevant and therefore cholesterol levels are not routinely checked during pregnancy, as a consequence of which there is scarce information on its global prevalence in pregnant women. Studies have reported that MH during pregnancy can cause atherogenesis in adults emphasizing the concept of in utero programming of fetus. Moreover, Gestational Diabetes Mellitus, obesity and Polycystic Ovary Syndrome are potential risk factors which strengthen combined pathologies in placenta and fetuses of mothers with MH. However, lack of conclusive evidence on cholesterol transport and underlying programming demand substantial research to develop population-based life style strategies for women in their childbearing years. The current review focuses on the mechanisms and outcomes of MH from existing epidemiological as well as experimental data and presents a detailed insight on this novel risk factor of cardiovascular diseases.

Lipoprotein (a): impact by ethnicity and environmental and medical conditions

Levels of lipoprotein (a) [Lp(a)], a complex between an LDL-like lipid moiety containing one copy of apoB, and apo(a), a plasminogen-derived carbohydrate-rich hydrophilic protein, are primarily genetically regulated. Although stable intra-individually, Lp(a) levels have a skewed distribution inter-individually and are strongly impacted by a size polymorphism of the LPA gene, resulting in a variable number of kringle IV (KIV) units, a key motif of apo(a). The variation in KIV units is a strong predictor of plasma Lp(a) levels resulting in stable plasma levels across the lifespan. Studies have demonstrated pronounced differences across ethnicities with regard to Lp(a) levels and some of this difference, but not all of it, can be explained by genetic variations across ethnic groups. Increasing evidence suggests that age, sex, and hormonal impact may have a modest modulatory influence on Lp(a) levels. Among clinical conditions, Lp(a) levels are reported to be affected by kidney and liver diseases.

Lipoprotein(a) is not related to markers of insulin resistance in pregnancy

BACKGROUND

Dyslipidemia, a major risk factor for cardiovascular disease is a common finding in patients with type 2 diabetes and among women with gestational diabetes. Elevated levels of lipoprotein(a) [Lp(a)] are linked to increased risk of cardiovascular disease. However, its relationship with insulin resistance, type 2 diabetes and gestational diabetes is controversial and unproven. Here we aimed to clarify whether Lp(a) levels are associated with insulin sensitivity in pregnancy.

METHODS

Sixty-four women with gestational diabetes and 165 with normal glucose tolerance were enrolled in the study. Fasting Lp(a) serum levels were measured in all women at 24-28 weeks of gestation.

RESULTS

In pregnancy, there was no significant difference in serum Lp(a) concentrations between the two groups. Its level did not correlate with markers of insulin resistance (HOMA-IR), insulin sensitivity (HOMA-S%), pancreatic beta-cell function (HOMA-B%) and insulin sensitivity in dynamic conditions (OGIS). In addition, fasting glucose and insulin levels and those throughout an oral glucose tolerance test were independent of Lp(a) concentrations in our study group.

CONCLUSIONS

Lp(a) levels in pregnant women do not differ with respect to the presence or absence of gestational diabetes. Although influenced by some components of the lipid profile, such as triglycerides and HDL-C, insulin resistance in pregnancy is not affected by Lp(a).

The current status of lipoprotein (a) in pregnancy: a literature review

BACKGROUND AND PURPOSE

Lipoprotein (Lp) (a) is a neglected element of the blood lipid profile. It is now recognized as a determinant of coronary heart disease progression and its role in atherosclerosis and its ability to induce thrombosis make it potentially important in the course of normal and complicated pregnancies. Pregnancy involves a major transformation of metabolism to sustain fetal growth. Multiple studies have been conducted on Lp(a) in pregnancy, and it is timely to synthesize and evaluate this evidence.

METHODS AND SUBJECTS

We reviewed the MEDLINE database for all articles published concerning "lipoprotein a" and "pregnancy" from May 2003 to May 2012. A previous comprehensive review assessed the literature up to May 2003.

RESULTS

We critically analyzed 14 studies detailing the effect of complications in pregnancy on Lp(a) profile, and subsequent pregnancy outcomes where available. Studies evaluating the normal metabolic response to pregnancy, pregnancies complicated by pre-eclampsia and intra-uterine growth restriction were reviewed.

CONCLUSIONS

A substantial mass of data has accumulated describing Lp(a) changes in pregnancy. The diversity of study design limits the ability to draw broad-ranging conclusions, but brings into focus the important questions remaining, which we discuss.

The role of lipoprotein (a) in pregnancies complicated by pre-eclampsia

Endothelial cell dysfunction is a key feature of the pathogenesis of pre-eclampsia. The cause of the endothelial cell injury is probably multifactorial, but poor placenta perfusion plays a major role. In pre-eclampsia, characteristic pathological lesions in the placenta are fibrin deposits, acute atherosis and thrombosis. The similarity between the lesions of pre-eclampsia and atherosclerosis has led to speculations of a common pathophysiological pathway. An abnormal lipid profile is known to be strongly associated with atherosclerotic cardiovascular disease and has a direct effect on endothelial function. Abnormal lipid metabolism seems important in the pathogenesis of pre-eclampsia too. An elevated plasma lipoprotein (a) concentration is a known risk factor for atherosclerotic cardiovascular disease. In this paper, we discuss three hypotheses about the mechanisms by which lipoprotein (a) may be associated with pre-eclampsia: 1. Lp(a), as an acute-phase reactant, transporting cholesterol to sites of endothelial damage for reparation, temporarily increases during pregnancy and increases more during a pregnancy complicated by mild to moderate pre-eclampsia as compared to an uncomplicated pregnancy, in response to a greater extend of endothelial injury in pre-eclampsia. After delivery, pre-eclampsia subsides and Lp(a) concentrations return to baseline levels. 2. In cases of severe pre-eclampsia, there is even more extensive endothelial damage and consequently a higher consumption of Lp(a) in reparation of this vascular damage. These women will have lower concentrations of Lp(a). 3. High baseline concentrations of Lp(a), which are genetically determined, may induce or contribute to the development of pre-eclampsia by promoting endothelial dysfunction. In this line of reasoning one would expect to find higher concentrations of Lp(a) in women at risk for developing pre-eclampsia in a future pregnancy or with a history of pre-eclampsia. As discussed above, these women are also at increased risk for future cardiovascular disease as compared to women with a history of normal pregnancy. The pathophysiologic changes associated with cardiovascular disease may also be responsible for the increased incidence of pre-eclampsia in these women.