Lipoprotein (a) and other prothrombotic risk factors in Caucasian women with unexplained recurrent miscarriage. Results of a multicentre case-control study

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.

Systematic review and meta-analysis of association between plasminogen activator inhibitor-1 4G/5G polymorphism and recurrent pregnancy loss: an update

BACKGROUND

We conducted this systematic review and meta-analysis to better understand the association between rs1799762 PAI-1 gene polymorphism and the risk of RPL.

METHODS

A systematic search for studies that assessed the association between PAI-1 4G/5G polymorphism and RPL risk published in search sources, PubMed/Medline, ISI Web of Knowledge, Scopus, and Google Scholar till January 2024 was conducted.

RESULTS

There were 23 case-control studies in total, with a high degree of statistical heterogeneity among them which indicated the need for subgroup analysis. We found a significant positive association between the risk of RPL and 4G/4G PAI-1 (OR: 2.57; 95% CI: 1.69-3.90), likewise 4G/5G (OR: 2/02 95% CI: 1.39-2.92) and mixed genotype (4G/4G+4G/5G) (OR: 2.31 95% CI: 1.81-2.93). Considering the ethnicity, the 4G/4G polymorphism is significantly associated with Asian descent (OR: 2.10; CI: 1.65-2.69) while the strong association (OR: 6.47; CI: 3.23-12.97) observed in the Greater Middle East descent is not statistically significant (P=0.16). PAI-1 4G/5G polymorphism association with RPL was only significant in Greater Middle East descent (OR: 2.93; CI: 2.41-3.56), and mixed genotype was significantly associated with RPL in Asian (OR: 2.37; CI: 1.55-3.61), Greater Middle East (OR: 3.01; CI: 2.16-4.19), and European populations (OR: 1.38; CI: 0.91-2.10). The association between RPL and PAI-1 4G/4G was significant for RPLs both under 12 weeks (OR: 1.82; 95% CI: 1.34-2.47), and under 24 weeks (OR: 1.46; 95% CI: 1.11-1.92), while considering heterozygote form the association was only significant for RPLs under 24 weeks (OR: 1.91; 95% CI: 1.58-2.31). Regarding the mixed genotype, there is a significant positive association between PAI-1 and RPL for RPLs under 12 weeks (OR: 2.09; 95% CI: 1.49-2.93), and under 24 weeks (OR: 2.10; 95% CI: 1.52-2.92).

CONCLUSIONS

Our findings indicate a significant association between the rs1799762 PAI-1 polymorphism and the risk of RPL.

Trends and consequences of lipoprotein(a) testing: Cross-sectional and longitudinal health insurance claims database analyses

BACKGROUND AND AIMS

Lipoprotein(a) (Lp(a)) is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). Our goal was to characterize patients undergoing Lp(a) testing and to assess the impact of Lp(a) testing on treatment changes and subsequent ASCVD events.

METHODS

A cross-sectional and a longitudinal claims data analysis were performed on 4 million patient records in Germany. Patients were followed up for a maximum of 4 years.

RESULTS

In 2015 and 2018, 0.25% and 0.34% of patients were tested, respectively. Testing was more frequent in younger women in the overall population, and in men in the ASCVD population. Patients tested for Lp(a) had more comorbidities and higher ASCVD risk compared to matched control patients. ASCVD hospitalizations were more frequent prior to the first Lp(a) test (5.55 vs 1.42 per 100/person-years). The mortality rate of the Lp(a)-tested cohort and the control group was similar. Mortality was lower in patients with prior ASCVD and Lp(a) testing compared to matched controls with prior ASCVD and no Lp(a) test (2.30 vs 3.64 per 100/person-years, p <0.001). Patients with Lp(a) test received more laboratory examinations and cardiovascular medications and had more visits with specialized physicians.

CONCLUSIONS

Lp(a) testing is rarely performed even in patients with very high cardiovascular risk. Patients tested for Lp(a) have more comorbidities and a higher ASCVD risk. Lp(a) testing is associated with more intensive preventive treatment and with positive effects on clinical outcomes and survival. The data support the value of Lp(a) measurements to characterize ASCVD risk and to improve ASCVD prevention.

The Role of Plasminogen Activator Inhibitor Type 1 (PAI-1) in Placenta-Mediated Pregnancy Complications: A Systematic Review

Plasminogen activator inhibitor type 1 (PAI-1) is a main inhibitor of fibrinolysis. The PAI-1 gene (SERPINE1) harbors genetic variants with the potential of modifying plasma levels of PAI-1. A delicate balance exists between the coagulation and fibrinolytic system, and changes in PAI-1 have been suggested to compromise establishment of a successful pregnancy. Therefore, this systematic review investigated the association between genetic variants and/or plasma levels of PAI-1 and placenta-mediated pregnancy complications. An extensive literature search was conducted in PubMed, Embase, and Web of Science on the 29^th of April 2021. All studies underwent quality rating according to The Study Quality Assessment Tools checklist provided by National Heart, Lung and Blood Institute. A total of 71 studies were included, among which 60 studies investigated PAI-1 genotypes and 11 studies measured PAI-1 plasma levels. In 32 out of 59 studies, no association was found between the PAI-1 4G/5G polymorphism (rs1799768) and placenta-mediated pregnancy complications, which was stated as no significant difference in the genotype distribution comparing women with and without placenta-mediated pregnancy complications or no significantly increased odds of placenta-mediated pregnancy complications carrying the 4G/4G or 4G/5G genotype. Eight out of 11 studies reported significantly higher PAI-1 plasma levels in preeclamptic women than in women without preeclampsia. In conclusion, no clear evidence indicates that PAI-1 polymorphisms are associated with placenta-mediated pregnancy complications, and the possible association between high PAI-1 plasma levels and preeclampsia needs further investigations. Thus, investigation of PAI-1 genotypes and PAI-1 plasma levels does not currently seem to have a place in daily clinical practice managing placenta-mediated pregnancy complications.

Hereditary thrombophilia and recurrent pregnancy loss: a systematic review and meta-analysis

STUDY QUESTION

Is there an association between hereditary thrombophilia in pregnant women and risk of recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

Pregnant women with hereditary thrombophilia have an increased risk of RPL, especially for pregnant women with the G1691A mutation of the factor V Leiden (FVL) gene, the G20210A mutation of the prothrombin gene (PGM), and deficiency of protein S (PS).

WHAT IS KNOWN ALREADY

Prior studies have suggested that pregnant women with hereditary thrombophilia have a higher risk of RPL, however, the results are inconsistent; furthermore, a complete overview is missing. This lack of information is an obstacle to the risk assessment of RPL in pregnant women with hereditary thrombophilia. A comprehensive meta-analysis on the relation between hereditary thrombophilia and the risk of RPL is needed.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis was performed using observational studies published in English before 1 April 2020 to evaluate the relation between hereditary thrombophilia and risk of RPL.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Relevant studies were identified from PubMed, Web of Science, and EMBASE searches and complemented with perusal of bibliographies of retrieved articles. The exposure of interest was hereditary thrombophilia, including FVL mutation, PGM, deficiency of antithrombin (AT), deficiency of protein C (PC), and deficiency of PS. The overall risk estimates were pooled using random effects models. Subgroup and sensitivity analyses were carried out to explore possible sources of heterogeneity and assess the robustness of the results.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 89 studies involving 30 254 individuals were included. Results showed that women with FVL mutation (odds ratio (OR): 2.44, 95% CI: 1.96-3.03), PGM (OR: 2.08, 95% CI: 1.61-2.68), or deficiency of PS (OR: 3.45, 95% CI: 1.15-10.35) had higher risks of developing RPL. Compared with the reference group, there was no observed relation between a deficiency in AT or PC and RPL (all P > 0.05). Heterogeneity in the risk estimates of RPL was partially explained by geographic region, definitions of RPL, types of RPL, and controlled confounders. Sensitivity analyses validated the robustness of the findings.

LIMITATIONS, REASONS FOR CAUTION

Only 39 of the included studies controlled for one or more confounders, and the heterogeneity across all included studies was high. Based on the data available, we cannot determine whether this association is confounded by other potential risk factors of RPL.

WIDER IMPLICATIONS OF THE FINDINGS

This systematic review and meta-analysis show a possible association between hereditary thrombophilia and an increased risk of RPL, suggesting that testing for hereditary thrombophilia should be considered in individuals with RPL.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Hunan Provincial Key Research and Development Program (Grant number: 2018SK2062) and National Natural Science Foundation Program (Grant number: 81973137). There are no conflicts of interest.

REGISTRATION NUMBER

N/A.

A Novel Review of Homocysteine and Pregnancy Complications

Homocysteine (Hct) is a substance produced in the metabolism of methionine. It is an essential type of amino acid gained from the daily diet. Methylenetetrahydrofolate reductase (MTHFR) gene mutation is related to elevated total homocysteine (tHct) expressions, in particular, among women with low folate intake. Hyperhomocysteinemia (HHct) is caused by numerous factors, such as genetic defects, lack of folic acid, vitamin B₆ and B₁₂ deficiency, hypothyroidism, drugs, aging, and renal dysfunction. Increased Hct in peripheral blood may lead to vascular illnesses, coronary artery dysfunction, atherosclerotic changes, and embolic diseases. Compared to nonpregnant women, the Hct level is lower in normal pregnancies. Recent studies have reported that HHct was associated with numerous pregnancy complications, including recurrent pregnancy loss (RPL), preeclampsia (PE), preterm delivery, placental abruption, fetal growth restriction (FGR), and gestational diabetes mellitus (GDM). Besides, it was discovered that neonatal birth weight and maternal Hct levels were negatively correlated. However, a number of these findings lack consistency. In this review, we summarized the metabolic process of Hct in the human body, the levels of Hct in different stages of normal pregnancy reported in previous studies, and the relationship between Hct and pregnancy complications. The work done is helpful for obstetricians to improve the likelihood of a positive outcome during pregnancy complications. Reducing the Hct level with a high dosage of folic acid supplements during the next pregnancy could be helpful for females who have suffered pregnancy complications due to HHct.

Interactions between genetic variants involved in the folate metabolic pathway and serum lipid, homocysteine levels on the risk of recurrent spontaneous abortion

Background

The interaction between folate pathway gene polymorphisms and homocysteine, serum lipid leverls are poorly understood in patients with recurrent spontaneous abortion (RSA). The aim of this study is to explore the effects of folate pathway gene polymorphisms (the 5–10-methylenetetrahydrofolate reductase, MTHTR C677T, MTHFR A1298C and the methionine synthase reductase, MTRR A66G) and their interactions with homocysteine on serum lipid levels in patients with RSA.

Methods

A total of 403 RSA women and 342 healthy women were randomly selected. Genotyping of the MTHFR C677T, A1298C and MTRR A66G were performed by TaqMan-MGB technique. Serum homocysteine, folate, fasting glucose, fasting insulin, Interleukin 6, Tumor necrosis factorα (TNFα) and lipid profiles were measured according to the kits. Continuous variables were analyzed using 2-sample t-tests. Categorical variables were analyzed and compared by χ² or Fisher’s exact tests. Unconditional logistic regression model was applied to test the interactions of gene polymorphisms on RSA.

Results

The distribution of genotype of CC, CT TT and T allele of MTHFR C677T, genotype of AA and C allele of MTHFR A1298C, and genotype of AA, AG and G allele of MTRR A66G were different between cases and controls (all p were < 0.05). There were significant interactions between MTHFR C677T-A1298C and MTHFR A1298C-MTRR A66G in RSA group and control group, with ORs of 1.62 (95%CI: 1.28–2.04, p < 0.001) and 1.55 (95%CI: 1.27–1.88, p < 0.001), respectively. Serum TNFα level and insulin resistant status (HOMR-IR) were higher in RSA group than in control group (p = 0.038, 0.001, respectively). All the three gene SNPs except MTRR 66AG gene variant had detrimental effects on HOMA-IR (all p were < 0.05). RSA group who carried the MTHFR 677CT, TT, CT/TT genotypes and MTRR 66AG, AG/GG genotypes had detrimental effects on serum homocysteine levels, the MTHFR 677CT, CT/TT genotype carriers had favorable effects on serum folate levels, the MTHFR 677TT, CT/TT, 1298 AC, AC/CC genotype carriers had detrimental effects on serum low-density lipoprotein cholesterol (LDL-C) levels, and the MTRR 66AG genotype carriers had lower high-density lipoprotein cholesterol (HDL-C) levels than the AA genotype carriers (all p were < 0.05).

Conclusions

Interaction between the MTHFR C677T, A1298C and MTHFR A1298C, MTRR A66G are observed in our RSA group. Besides, all the three gene SNPs except MTRR 66AG gene variant had detrimental effects on HOMA-IR. MTHFR C677T and MTRR A66G gene variants had detrimental effects on serum homocysteine levels and insulin resistance status, while MTHFR C677T, A1298C and MTRR A66G gene variants had detrimental effects on certain serum lipid profiles.

Lipoprotein(a): An underrecognized genetic risk factor for malignant coronary artery disease in young Indians

Malignant coronary artery disease (CAD) refers to a severe and extensive atherosclerotic process involving multiple coronary arteries in young individuals (aged <45 years in men and <50 years in women) with a low or no burden of established risk factors. Indians, in general, develop acute myocardial infarction (AMI) about 10 years earlier; AMI rates are threefold to fivefold higher in young Indians than in other populations. Although established CAD risk factors have a predictive value, they do not fully account for the excessive burden of CAD in young Indians. Lipoprotein(a) (Lp(a)) is increasingly recognized as the strongest known genetic risk factor for premature CAD, with high levels observed in Indians with malignant CAD. High Lp(a) levels confer a twofold to threefold risk of CAD-a risk similar to that of established risk factors, including diabetes. South Asians have the second highest Lp(a) levels and the highest risk of AMI from the elevated levels, more than double the risk observed in people of European descent. Approximately 25% of Indians and other South Asians have elevated Lp(a) levels (≥50 mg/dl), rendering Lp(a) a risk factor of great importance, similar to or surpassing diabetes. Lp(a) measurement is ready for clinical use and should be an essential part of all CAD research in Indians.

Elevated lipoprotein (a) levels are an independent risk factor for retinal vein occlusion

PURPOSE

To investigate the prevalence of lipoprotein (a) [Lp(a)] and other thrombophilic disorders among retinal vein occlusion (RVO) patients with regard to age and various risk factors.

METHODS

We retrospectively reviewed the medical records of 100 patients with central, hemicentral or branch RVO who had undergone routine thrombophilia screening. Data were compared with 100 controls. Both cohorts were divided into three subgroups (≤45 years, >45-≤60 years or >60 years), depending on the patients' age at the time of the RVO or a previous thromboembolic event.

RESULTS

Elevated Lp(a) plasma levels were significantly more prevalent among RVO patients than among controls (p < 0.0001; OR: 4.8). Moreover, we determined age ≤60 years by the time of the first thromboembolic event as a strong predictor of elevated Lp(a) (p = 0.0002). The coincidence of elevated Lp(a) with other coagulation disorders further increased the OR for RVO to 9.3 (95% CI 2.1-41.8). Multivariate analysis revealed the presence of cardiovascular risk factors (OR: 3.1, p = 0.0004), elevated lipoprotein (a) levels (OR: 5.2, p = 0.0001) and increased factor VIII activity (OR: 5.9, p = 0.001) as independent risk factors for the development of RVO among patients.

CONCLUSION

Our results indicate that elevated plasma levels of Lp(a) are associated with the development of RVO. Selective screening of young patients and subjects with a personal or family history of thromboembolism may be helpful in identifying RVO patients with elevated Lp(a).

Acute lower limb ischemia due to thrombo-embolic arterial occlusions in two previously healthy men with markedly elevated Lp(a)

Lipoprotein (a) (Lp(a)) is a well-documented risk factor for atherosclerotic cardiovascular disease. Its role in acute thrombo-embolic occlusions of peripheral arteries is not known. We describe two cases of multiple, acute, peripheral arterial occlusions in two previously healthy men with markedly elevated Lp(a). Both cases had unsatisfactory results after percutaneous and surgical revascularization procedures. Experience yielded in these two cases suggests that when an unfavorable out-come occurs in a peripheral artery disease patient in the absence of the regular risk factors, Lp(a) should be determined and its role investigated.

Selective Thrombophilia Screening in Young Patients with Retinal Artery Occlusion

Purpose: To investigate the prevalence of various thrombophilic disorders among young patients with retinal artery occlusion (RAO). Procedures: We retrospectively reviewed thrombophilia screening data of young patients ≤60 years of age with RAO and healthy controls matched for gender and age. Results: Thrombophilia screening data of 25 young patients and 62 healthy controls were analyzed. Mean patient age by the time of the RAO was 43.3 ± 10.8 years. Overall, thrombophilic defects were found to be present in 17 patients (68%) compared with 11 of 62 controls (17.7%; p < 0.0001). Multivariate logistic regression analysis confirmed a statistically significant association between the development of RAO and increased levels of lipoprotein(a) (odds ratio: 9.48; p = 0.001) and factor VIII (odds ratio: 6.41; p = 0.024). There was a strong association between the presence of thrombophilic disorders and a personal or family history of thromboembolism (p = 0.01). Conclusions: Our results indicate that screening for thrombophilic disorders among selected young patients with RAO yields positive results in a high percentage of cases.

Association of a methylene tetrahydrofolate reductase C677T polymorphism with several blood chemical levels in a Chinese population

BACKGROUND

The methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism is associated with hypertension in certain populations. This study investigated the relationship between the MTHFR polymorphism and hypertension and correlated blood lipid indexes, including homocysteine (HCY), lipoprotein (a) [Lp (a)], high-density lipoprotein (HDL), low-density lipoprotein (LDL), apolipoprotein A I (Apo AI), Apo B, glucose (GLU), total cholesterol (TC), and triglyceride (TG), in a Chinese population.

MATERIALS AND METHODS

A total of 174 patients with hypertension and 634 healthy control individuals from Jiangxi Province were recruited between June 2012 and September 2012 for genotyping of the MTHFR C677T polymorphism using polymerase chain reaction-restriction fragment length polymorphism. Biochemical parameters were also assessed in these subjects and statistically compared to the MTHFR C677T polymorphism and the risk for hypertension.

RESULTS

HCY and Lp (a) levels were significantly higher in subjects with a MTHFR 677TT genotype than in those with a CC/CT genotype, independent of hypertension. The frequency of the TT genotype and the T allele in hypertension patients was significantly higher than in the healthy controls. Furthermore, in the male hypertension patient group, the average levels of HCY, HDL, Apo AI, and TC were significantly different from those in female hypertension patients (pHCY=0.001, pHDL=0.004, pApo AI<0.001, pTC=0.012). In the male control group, the average levels of HCY, HDL, Apo AI, GLU, and TC were significantly different from those of female controls (pHCY<0.001, pHDL<0.001, pApo AI<0.001, pGLU=0.001, and pTC=0.004).

CONCLUSION

Our data demonstrate that the MTHFR C677T polymorphism is positively correlated with an increased risk of hypertension through an increase in HCY levels. The blood lipid correlative index was different between male and female hypertension patients and controls.

Low-molecular-weight heparin for women with unexplained recurrent pregnancy loss: a multicenter trial with a minimization randomization scheme

BACKGROUND

A daily injection of low-molecular-weight heparin (LMWH) is often prescribed to women with unexplained recurrent pregnancy loss (RPL), although evidence suggesting a benefit is questionable.

OBJECTIVE

To determine whether LMWH increases ongoing pregnancy and live-birth rates in women with unexplained RPL.

DESIGN

Controlled, multicenter trial with randomization using minimization conducted from 2006 to 2013. (ClinicalTrials.gov: NCT00400387).

SETTING

14 university hospitals and perinatal care centers in Germany and Austria.

PATIENTS

449 women with at least 2 consecutive early miscarriages or 1 late miscarriage were included during 5 to 8 weeks' gestation after a viable pregnancy was confirmed by ultrasonography.

INTERVENTION

Women in the control group received multivitamin pills, and the intervention group received vitamins and 5000 IU of dalteparin-sodium for up to 24 weeks' gestation.

MEASUREMENTS

Primary outcome was ongoing pregnancy at 24 weeks' gestation. Secondary outcomes included the live-birth rate and late pregnancy complications.

RESULTS

At 24 weeks' gestation, 191 of 220 pregnancies (86.8%) and 188 of 214 pregnancies (87.9%) were intact in the intervention and control groups, respectively (absolute difference, -1.1 percentage points [95% CI, -7.4 to 5.3 percentage points]). The live-birth rates were 86.0% (185 of 215 women) and 86.7% (183 of 211 women) in the intervention and control groups, respectively (absolute difference, -0.7 percentage point [CI, -7.3 to 5.9 percentage points]). There were 3 intrauterine fetal deaths (1 woman had used LMWH); 9 cases of preeclampsia or the hemolysis, elevated liver enzyme level, and low platelet count (HELLP) syndrome (3 women had used LMWH); and 11 cases of intrauterine growth restriction or placental insufficiency (5 women had used LMWH).

LIMITATION

Placebo injections were not used, and neither trial staff nor patients were blinded.

CONCLUSION

Daily LMWH injections do not increase ongoing pregnancy or live-birth rates in women with unexplained RPL. Given the burden of the injections, they are not recommended for preventing miscarriage.

PRIMARY FUNDING SOURCE

Pfizer Pharma.

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.

Association of the R67X and W303X non-sense polymorphisms in the protein Z-dependent protease inhibitor gene with idiopathic recurrent miscarriage

Protein Z-dependent protease inhibitor (ZPI) is a 72 kDa single-chain serpin which inhibits the activated coagulation factors X and XI. Two non-sense polymorphisms of ZPI, R67X and W303X, were recently identified, and were linked with a prothrombotic state. Here, we investigated the association of the R67X (728C>T) and W303X (1438G>A) variants in the ZPI gene with recurrent spontaneous miscarriage (RSM). This was a case-control study involving a total of 288 women with a history of two consecutive or ≥3 non-consecutive pregnancy losses between 8 and 12th week of gestation, along with 304 age-matched and ethnically matched multiparous control women, with no personal or family history of pregnancy complications. The minor allele frequency of R67X (P = 0.003) and W303X (P = 0.014) were higher in RSM cases than in control women. Both single-nucleotide polymorphisms were significantly associated with RSM under the dominant genetic association model, and were in moderate linkage disequilibrium (D' = 0.412; P < 0.001). Taking the common (728)C/(1438)G haplotype as reference, multivariate analysis confirmed the positive association of (728)T/(1438)G [P = 0.043; odds ratio (OR) = 2.25; 95% confidence interval (CI) = 1.03-4.90], and (728)T/(1438)A (P = 0.022; OR = 3.93; 95% CI = 1.23-12.59) haplotypes with increased RSM risk. These differences remained significant after controlling for some covariates. These results demonstrate that both ZPI R67X and W303X non-sense variants and specific ZPI haplotypes are significantly associated with RSM.

Can Factor V Leiden and prothrombin G20210A testing in women with recurrent pregnancy loss result in improved pregnancy outcomes?: Results from a targeted evidence-based review

Women with recurrent pregnancy loss are offered Factor V Leiden (F5) and/or prothrombin G20210A (F2) testing to identify candidates for anticoagulation to improve outcomes. A systematic literature review was performed to estimate test performance, effect sizes, and treatment effectiveness. Electronic searches were performed through April 2011, with review of references from included articles. English-language studies addressed analytic validity, clinical validity, and/or clinical utility and satisfied predefined inclusion criteria. Adequate evidence showed high analytic sensitivity and specificity for F5 and F2 testing. Evidence for clinical validity was adequate. The summary odds ratio for association of recurrent pregnancy loss with F5 in case-controlled studies was 2.02 (95% confidence interval, 1.60-2.55), with moderate heterogeneity and suggestion of publication bias. Longitudinal studies in women with recurrent pregnancy loss or unselected cohorts showed F5 carriers were more likely to have a subsequent loss than noncarriers (odds ratios: 1.93 and 2.03, respectively). Results for F2 testing were similar. For clinical utility, evidence was adequate that anticoagulation treatments were ineffective (except in antiphospholipid antibody syndrome) and had treatment-associated harms. The certainty of evidence is moderate (high, moderate, and low) that anticoagulation of women with recurrent pregnancy loss and F5/F2 variants would currently lead to net harms.

Association of Apo(a)isoform size with dyslipoproteinemia in male venous thrombosis patients

BACKGROUND

Lp(a) is a proatherogenic lipoprotein that may also be prothrombotic. Apo(a) size isoforms have differential effects on fibrinolysis. Whereas Lp(a) concentrations have been linked to venous thromboembolic disease (VTE) risk, apo(a) polymorphisms in VTE have not been studied.

METHODS

We used a standardized high resolution agarose gel electrophoresis technique to determine apo(a) isoform size, and a Lp(a) immunoassay insensitive to apo(a) size to measure Lp(a) concentration in 46 men with VTE and 46 age-matched healthy controls.

RESULTS

Apo(a) isoform distribution in VTE cases and controls was bimodal and VTE patients tended to have more medium-sized isoforms K(4)-(19-27) (54.3% vs. 34.8%, p=0.06). Cases and controls had the same median predominant apo(a) size isoform (23.5 K(4) repeats) and comparable Lp(a) concentrations. However, subgroup analysis based on apo(a) isoform size (K(4)< or =23 or K(4)> or =24) revealed that cases in the K(4)> or =24 subgroup had higher Lp(a) concentrations than the controls in this isofrom subgroup (14.5 mmol vs. 6.6 mmol, p=0.029). Also, dyslipoproteinemia (smaller LDL and HDL particles, higher LDL and lower HDL parameters) was strongly associated with VTE only in this larger apo(a) isoform group.

CONCLUSIONS

These observations provide the first evidence that determination of apo(a) isoforms may provide useful novel insights into VTE risk.

Methylenetetrahydrofolate reductase C677T polymorphism and the risk of unexplained recurrent pregnancy loss: a meta-analysis

OBJECTIVE

To investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and the risk of unexplained recurrent pregnancy loss (URPL).

DESIGN

Meta-analysis of published case-control studies of the MTHFR C677T variant and URPL risk.

SETTING

A research institution in China.

PATIENT(S)

Women with URPL.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Odds ratios (ORs) and 95% confidence intervals (CIs) for TT versus CC genotype, CT versus CC genotype, TT versus CT and CC genotype combined, and for T versus C allele.

RESULT(S)

Twenty-six studies with 2120 URPL cases and 2949 controls were included. Overall random-effects ORs of 1.49 (95% CI, 1.12-2.00) for TT versus CC genotype, 1.40 (95% CI, 1.11-1.77) for TT versus CT and CC genotype combined, and 1.21 (95%CI, 1.04-1.40) for T versus C allele were found. Stratified analysis showed that significant strong associations between MTHFR C677T polymorphism and URPL were present only in the five Chinese studies (OR = 2.96 for TT versus CC genotype; OR = 2.30 for TT versus CT+CC genotype; OR = 1.73 for T versus C allele), but not in any other studies, including the studies conducted in the European countries.

CONCLUSION(S)

The MTHFR C677T mutation is not a genetic risk factor for URPL except in a Chinese population.