Lipoprotein(a) and risk of myocardial infarction--genetic epidemiologic evidence of causality

The dynamic inflammatory profile of pregnancy can be monitored using a novel lipid-based mass spectrometry technique

The lipid environment changes throughout pregnancy both physiologically with emergent insulin resistance and pathologically e.g., gestational diabetes mellitus (GDM). Novel mass spectrometry (MS) techniques applied to minimally processed blood might lend themselves to monitoring changing lipid profiles to inform care decisions across pregnancy. In this study we use an intact-sandwich, MALDI-ToF MS method to identify phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) species and calculate their ratio as an indicator of inflammation. Plasma and sera were prepared from venous blood of non-pregnant women (aged 18-40) and pregnant women at 16 weeks, 28 weeks (including GDM-positive women), and 37+ weeks (term) of gestation alongside umbilical cord blood (UCB). Women with a normal menstrual cycle and age-matched men provided finger-prick derived capillary sera at 6 time-points over a month. Serum rather than plasma was preferable for PC/LPC measurement. As pregnancy progresses, an anti-inflammatory phenotype dominates the maternal circulation, evidenced by increasing PC/LPC ratio. In contrast, the PC/LPC ratio of UCB was aligned to that of non-pregnant donors. BMI had no significant effect on the PC/LPC ratio, but GDM-complicated pregnancies had significantly lower PC/LPC at 16 weeks of gestation. To further translate the use of the PC/LPC ratio clinically, the utility of finger-prick blood was evaluated; no significant difference between capillary versus venous serum was found and we revealed the PC/LPC ratio oscillates with the menstrual cycle. Overall, we show that the PC/LPC ratio can be measured simply in human serum and has the potential to be used as a time-efficient and less invasive biomarker of (mal)adaptative inflammation.

Relationship between lipoprotein (a) and subclinical carotid atherosclerosis in asymptomatic individuals

BACKGROUND

This study aimed to evaluate the associations between Lipoprotein (a) ‒ Lp(a) levels and carotid Intima-Media Thickness (cIMT) and with carotid plaques in healthy subjects because of previous contradictory data.

METHODS

A total of 317 healthy normolipidemic subjects (20‒77 years old) were selected. The cIMT and atherosclerotic plaques were determined by B-mode ultrasonography. Mann-Whitney tests were performed to compare the groups according to Lp(a) levels and to explore the associations between Lp(a), carotid plaques, and cIMT, logistic and linear regression analyses were performed.

RESULTS

Studied population (51% females, median age 43 years old) presented carotid plaques and cIMT ≥ 0.9 mm in 23% and 18% of the participants, respectively. The group with Lp(a) levels > 30 mg/dL presented significantly higher age and atherosclerotic plaques. Indeed, multivariate linear regression analysis showed a significant association between Lp(a), age, and race. On the other hand, logistic regression analysis demonstrated that the subjects with Lp(a) > 30 mg/dL have a significantly high risk of carotid plaques.

CONCLUSION

The data from the present study indicate that Lp(a) levels above 30 mg/dL contribute to the development of carotid plaques even in apparently healthy participants.

Changes of Certain Metabolic and Cardiovascular Markers Fructosamine, H-FABP and Lipoprotein (a) in Patients with Hypothyroidism

Background:

Disorders of thyroid gland are common in general population, and it’s the most common affecting the endocrine system after diabetes mellitus. Thyroid function regulates a wide range of metabolic parameters, as well as affects some cardiovascular disease risk factors. Fructosamine is produced by a reaction between albumin (protein) and glucose; it is used to monitor patients with diabetes for short-term glycemic changes. H-FABP is present in the cytoplasm of cardiac myocytes, and delivers fatty acids into these cells. It has been shown to increase in myocardial injury. Lipoprotein LP(a) is consist of a special apolipoprotein called apoprotein (a), and it’s recognized as a cardiovascular disease independent risk factor.

Objective:

To study whether certain metabolic and cardiovascular markers (fructosamine, H-FABP and lipoprotein (a) are changed in hypothyroid patients.

Methods:

The current study included 280 overt hypothyroid, 272 with subclinical hypothyroidism compared with 270 healthy individuals of matched age and gender. For all subjects serum (TSH, T4, T3, FBS, HbA1c, fructosamine, triglycerides, cholesterol, lipoprotein (a), and Heart-type Fatty Acid-Binding Protein (H-FABP)) was measured.

Results:

Serum fructosamine level significantly elevated (p value <0.05) in patient with hypothyroidism when compared with control group, and no significant change between subclinical and control groups. There is no significant change in serum H-FABP between study subjects. There is significant increase in lipoprotein (a) in patient with hypothyroidism and those with subclinical group when compared with control group.

Conclusion:

Serum fructosamine and level is significantly changed in patients with overt hypothyroidism when compared with euthyroid subjects. Also, we conclude that hypothyroidism increase risk of cardiovascular diseases by changing non-traditional marker such as lipoprotein (a), and no effect on H-FABP concentration.

Identification and analyses of inhibitors targeting apolipoprotein(a) kringle domains KIV-7, KIV-10, and KV provide insight into kringle domain function

Increased plasma concentrations of lipoprotein(a) (Lp(a)) are associated with an increased risk for cardiovascular disease. Lp(a) is composed of apolipoprotein(a) (apo(a)) covalently bound to apolipoprotein B of low-density lipoprotein (LDL). Many of apo(a)'s potential pathological properties, such as inhibition of plasmin generation, have been attributed to its main structural domains, the kringles, and have been proposed to be mediated by their lysine-binding sites. However, available small-molecule inhibitors, such as lysine analogs, bind unselectively to kringle domains and are therefore unsuitable for functional characterization of specific kringle domains. Here, we discovered small molecules that specifically bind to the apo(a) kringle domains KIV-7, KIV-10, and KV. Chemical synthesis yielded compound AZ-05, which bound to KIV-10 with a K_d of 0.8 μm and exhibited more than 100-fold selectivity for KIV-10, compared with the other kringle domains tested, including plasminogen kringle 1. To better understand and further improve ligand selectivity, we determined the crystal structures of KIV-7, KIV-10, and KV in complex with small-molecule ligands at 1.6-2.1 Å resolutions. Furthermore, we used these small molecules as chemical probes to characterize the roles of the different apo(a) kringle domains in in vitro assays. These assays revealed the assembly of Lp(a) from apo(a) and LDL, as well as potential pathophysiological mechanisms of Lp(a), including (i) binding to fibrin, (ii) stimulation of smooth-muscle cell proliferation, and (iii) stimulation of LDL uptake into differentiated monocytes. Our results indicate that a small-molecule inhibitor targeting the lysine-binding site of KIV-10 can combat the pathophysiological effects of Lp(a).

Plasma proteomic and autoantibody profiles reveal the proteomic characteristics involved in longevity families in Bama, China

Background

Chinese Bama Yao Autonomous County is a well-known longevity region in the world. In the past 30 years, population and genome studies were undertaken to investigate the secret of longevity and showed that longevity is the result of a combination of multiple factors, such as genetic, environmental and other causes. In this study, characteristics of the blood plasma proteomic and autoantibody profiles of people from Bama longevity family were investigated.

Methods

Sixty-six plasma donors from Chinese Bama longevity area were recruited in this study. Thirty-three offsprings of longevous families were selected as case studies (Longevous group) and 33 ABO (blood type), age, and gender-matched subjects from non-longevous families were selected as controls (Normal group). Each group contains 3 biological replicates. Tandem mass tag-based proteomic technique was used to investigate the differentially expressed plasma proteins between the two groups. The auto-reactive IgG antibody profiles of the 3 pooled samples in each group were revealed by human proteome microarrays with 17,000 recombinant human proteins.

Results

Firstly, 525 plasma proteins were quantified and 12 proteins were discovered differentially expressed between the two groups. Secondly, more than 500 proteins were recognized by plasma antibodies, 14 proteins ware differentially reacted with the autoantibodies in the two groups. Bioinformatics analysis showed some of the differential proteins and targeted autoantigens were involved in cancer, cardiovascular disease and immunity.

Conclusions

Proteomic and autoantibody profiles varied between the offspring of longevous and normal families which are from the same area and shared the same environmental factors. The identified differences were reported to be involved in several physiological and pathological pathways. The identified proteins will contribute to a better understanding of the proteomic characteristics of people from Bama longevous area and a revelation of the molecular mechanisms of longevity.

Lipoprotein(a)-an interdisciplinary challenge

Lipoprotein(a) (Lp(a)) is an internationally recognized atherogenic risk factor which is inherited and not changed by nutrition or physical activity. At present, only proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors may modestly decrease its concentration (but not in all patients)-leading to a certain decrease in cardiovascular events (CVE) in controlled studies. However, at present an elevation of Lp(a) is not a generally accepted indication for their use. More effective is lipoprotein apheresis (LA) therapy with respect to both lowering Lp(a) levels and reduction of CVE. In the future, an antisense oligonucleotide against apolipoprotein(a) will probably be available. Atherosclerosis in patients with an elevation of Lp(a) may affect several vessel regions (carotids, aorta, coronaries, leg arteries). Thus, Lp(a) should be measured in high-risk patients. These patients are usually cared for by their family doctors and by other specialists who should closely cooperate. Lipidologists should decide whether costly therapies like PCSK9 inhibitors or LA should be started. The main aim of current therapy is to optimize all other risk factors (LDL cholesterol, hypertension, diabetes mellitus, body weight, renal insufficiency). Patients should be regularly monitored (lab data, heart, arteries). This paper describes the duties of physicians of different specialties when caring for patients with high Lp(a) concentrations.

Lipoprotein(a): An independent, genetic, and causal factor for cardiovascular disease and acute myocardial infarction

Lipoprotein(a) [Lp(a)] is a circulating lipoprotein, and its level is largely determined by variation in the Lp(a) gene (LPA) locus encoding apo(a). Genetic variation in the LPA gene that increases Lp(a) level also increases coronary artery disease (CAD) risk, suggesting that Lp(a) is a causal factor for CAD risk. Lp(a) is the preferential lipoprotein carrier for oxidized phospholipids (OxPL), a proatherogenic and proinflammatory biomarker. Lp(a) adversely affects endothelial function, inflammation, oxidative stress, fibrinolysis, and plaque stability, leading to accelerated atherothrombosis and premature CAD. The INTER-HEART Study has established the usefulness of Lp(a) in assessing the risk of acute myocardial infarction in ethnically diverse populations with South Asians having the highest risk and population attributable risk. The 2018 Cholesterol Clinical Practice Guideline have recognized elevated Lp(a) as an atherosclerotic cardiovascular disease risk enhancer for initiating or intensifying statin therapy.

South Asian Cardiovascular Disease & Cancer Risk: Genetics & Pathophysiology

South Asians (SAs) are at heightened risk for cardiovascular disease as compared to other ethnic groups, facing premature and more severe coronary artery disease, and decreased insulin sensitivity. This disease burden can only be partially explained by conventional risk factors, suggesting the need for a specific cardiovascular risk profile for SAs. Current research, as explored through a comprehensive literature review, suggests the existence of population specific genetic risk factors such as lipoprotein(a), as well as population specific gene modulating factors. This review catalogues the available research on cardiovascular disease and genetics, anthropometry, and pathophysiology, and cancer genetics among SAs, with a geographical focus on the U.S. A tailored risk profile will hinge upon population customized classification and treatment guidelines, informed by continued research.

The effects of coenzyme Q10 supplementation on gene expression related to insulin, lipid and inflammation in patients with polycystic ovary syndrome

OBJECTIVE

This research was conducted to assess the effects of coenzyme Q10 (CoQ10) intake on gene expression related to insulin, lipid and inflammation in subjects with polycystic ovary syndrome (PCOS).

METHODS

This randomized double-blind, placebo-controlled trial was conducted on 40 subjects diagnosed with PCOS. Subjects were randomly allocated into two groups to intake either 100 mg CoQ10 (n = 20) or placebo (n = 20) per day for 12 weeks. Gene expression related to insulin, lipid and inflammation were quantified in blood samples of PCOS women with RT-PCR method.

RESULTS

Results of RT-PCR shown that compared with the placebo, CoQ10 intake downregulated gene expression of oxidized low-density lipoprotein receptor 1 (LDLR) (p < 0.001) and upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (p = 0.01) in peripheral blood mononuclear cells of subjects with PCOS. In addition, compared to the placebo group, CoQ10 supplementation downregulated gene expression of interleukin-1 (IL-1) (p = 0.03), interleukin-8 (IL-8) (p = 0.001) and tumor necrosis factor alpha (TNF-α) (p < 0.001) in peripheral blood mononuclear cells of subjects with PCOS.

CONCLUSIONS

Overall, CoQ10 intake for 12 weeks in PCOS women significantly improved gene expression of LDLR, PPAR-γ, IL-1, IL-8 and TNF-α.

Eligibility for alirocumab or evolocumab treatment in 1090 hypercholesterolemic patients referred to a regional cholesterol treatment center with LDL cholesterol ≥70 mg/dL despite maximal-tolerated LDL-cholesterol-lowering therapy

Background

Proprotein convertase subtilisin/kexin type 9 inhibitors, Praluent (alirocumab [ALI]) and Repatha (evolocumab [EVO]) have been approved as adjuncts to the standard-of-care maximal-tolerated dose (MTD) of low-density lipoprotein cholesterol (LDLC)-lowering therapy (LLT), statin therapy, in heterozygous (HeFH) (ALI or EVO) or homozygous (EVO) familial hypercholesterolemia, or clinical atherosclerotic cardiovascular disease (CVD) where LDLC lowering is insufficient (both). Since LDLC lowering has been revolutionized by ALI and EVO, specialty pharmaceutical pricing models will be applied to a mass market.

Methods

We applied US Food and Drug Administration (FDA) and insurance eligibility criteria for ALI and EVO to 1090 hypercholesterolemic patients serially referred over 3 years who then received ≥2 months maximal-tolerated dose of standard-of-care LDL cholesterol-lowering therapy (MTDLLT) with follow-up LDLC ≥70 mg/dL. MTDLLT did not include ALI or EVO, which had not been commercially approved before completion of this study.

Results

Of the 1090 patients, 140 (13%) had HeFH by clinical diagnostic criteria and/or CVD with LDLC >100 mg/dL despite ≥2 months on MTDLLT, meeting FDA insurance criteria for ALI or EVO therapy. Another 51 (5%) patients were statin intolerant, without HeFH or CVD.

Conclusion

If 13% of patients with HeFH-CVD and LDLC >100 mg/dL despite MTDLLT are eligible for ALI or EVO, then specialty pharmaceutical pricing models (~$14,300/year) might be used in an estimated 10 million HeFH-CVD patients. Whether the health care savings arising from the anticipated reduction of CVD events by ALI or EVO justify their costs in populations with HeFH-CVD and LDLC >100 mg/dL despite MTDLLT remains to be determined.

The Effects of Omega-3 Fatty Acids Supplementation on Gene Expression Involved in the Insulin and Lipid Signaling Pathway in Patients with Polycystic Ovary Syndrome

Limited data are available evaluating the effects of omega-3 fatty acids supplementation on gene expression involved in the insulin and lipid-signaling pathway in women with polycystic ovary syndrome (PCOS). This study was conducted to evaluate the effects of omega-3 fatty acids supplementation on gene expression involved in the insulin and lipid signaling pathway in women with PCOS. This randomized double blind, placebo-controlled trial was done among 60 women aged 18-40 years old and diagnosed with PCOS according to the Rotterdam criteria. Participants were randomly assigned into 2 groups to receive either 1 000 mg omega-3 fatty acids from flaxseed oil containing 400 mg α-linolenic acid (n=30) or placebo (n=30) twice a day for 12 weeks. Gene expressions involved in the insulin and lipid-signaling pathway were quantified in blood samples of PCOS women with RT-PCR method. Quantitative results of RT-PCR demonstrated that compared with the placebo, omega-3 fatty acids supplementation upregulated peroxisome proliferator-activated receptor gamma (PPAR-γ) mRNA (p=0.005) in peripheral blood mononuclear cells of women with PCOS. In addition, compared to the placebo, omega-3 fatty acids supplementation downregulated expressed levels of oxidized low-density lipoprotein receptor (LDLR) mRNA (p=0.002) in peripheral blood mononuclear cells of women with PCOS. We did not observe any significant effect of omega-3 fatty acids supplementation on expressed levels of glucose transporter 1 (GLUT-1) and lipoprotein(a) [Lp(a)] genes in peripheral blood mononuclear cells. Overall, omega-3 fatty acids supplementation for 12 weeks in PCOS women significantly improved gene expression of PPAR-γ and LDLR.

The effects of omega-3 fatty acids and vitamin E co-supplementation on gene expression of lipoprotein(a) and oxidized low-density lipoprotein, lipid profiles and biomarkers of oxidative stress in patients with polycystic ovary syndrome

This study was conducted to determine the effects of omega-3 fatty acids and vitamin E co-supplementation on gene expression of lipoprotein(a) (Lp[a]) and oxidized low-density lipoprotein (Ox-LDL), lipid profiles and biomarkers of oxidative stress in women with polycystic ovary syndrome (PCOS). This randomized double-blind, placebo-controlled trial was done on 68 women diagnosed with PCOS according to the Rotterdam criteria aged 18-40 years old. Participants were randomly assigned into two groups to receive either 1000 mg omega-3 fatty acids from flaxseed oil containing 400 mg α-Linolenic acid plus 400 IU vitamin E supplements (n = 34) or placebo (n = 34) for 12 weeks. Lp(a) and Ox-LDL mRNA levels were quantified in peripheral blood mononuclear cells of PCOS women with RT-PCR method. Lipid profiles and biomarkers of oxidative stress were quantified at the beginning of the study and after 12-week intervention. Quantitative results of RT-PCR demonstrated that compared with the placebo, omega-3 fatty acids and vitamin E co-supplementation downregulated expressed levels of Lp(a) mRNA (P < 0.001) and Ox-LDL mRNA (P < 0.001) in peripheral blood mononuclear cells of women with PCOS. In addition, compared to the placebo group, omega-3 fatty acids and vitamin E co-supplementation resulted in a significant decrease in serum triglycerides (-22.1 ± 22.3 vs. +7.7 ± 23.6 mg/dL, P < 0.001), VLDL- (-4.4 ± 4.5 vs. +1.5 ± 4.7 mg/dL, P < 0.001), total- (-20.3 ± 16.6 vs. +12.2 ± 26.1 mg/dL, P < 0.001), LDL- (-16.7 ± 15.3 vs. +11.9 ± 26.1 mg/dL, P < 0.001) and total-/HDL-cholesterol (-0.5 ± 0.6 vs. +0.4 ± 0.8, P < 0.001). There were a significant increase in plasma total antioxidant capacity (+89.4 ± 108.9 vs. +5.9 ± 116.2 mmol/L, P = 0.003) and a significant decrease in malondialdehyde levels (-0.3 ± 0.4 vs. -0.008 ± 0.6 μmol/L, P = 0.01) by combined omega-3 fatty acids and vitamin E intake compared with the placebo group. Overall, omega-3 fatty acids and vitamin E co-supplementation for 12 weeks in PCOS women significantly improved gene expression of Lp(a) and Ox-LDL, lipid profiles and biomarkers of oxidative stress.

Association of a gain-of-function variant in LGR4 with central obesity

OBJECTIVE

To determine the relationship of the gain-of-function variant A750T in leucine-rich repeat containing G protein-coupled receptor 4 (LGR4) with central obesity and related metabolic phenotypes.

METHODS

The LGR4 A750T (c.2248 G > A) variant was detected by Sanger sequencing in a discovery young population and a validation community-based population with obesity from eastern China. Fat indices determined by anthropometry and computed tomography scans and clinical biochemical measurements were collected for association analysis.

RESULTS

LGR4 A750T was significantly correlated with waist circumference (P = 0.030) and waist-to-height ratio (P < 0.001) in the young cohort (N = 594) and with waist-to-hip ratio (P = 0.013) in the community population (N = 1067). Combined analysis showed a significant correlation of the variant with waist circumference (P < 0.001) and waist-to-hip ratio (P = 0.021). Moreover, the variant had a remarkable correlation with abdominal visceral fat area (P = 0.004) and was associated with 2-h plasma insulin (P = 0.009) and the Matsuda index (P = 0.027) after an oral glucose tolerance test in young subjects with obesity.

CONCLUSIONS

The LGR4 A750T variant may contribute to central obesity characterized by abdominal visceral fat accumulation.

Systems analysis of gene ontology and biological pathways involved in post-myocardial infarction responses

Background

Pathway analysis has been widely used to gain insight into essential mechanisms of the response to myocardial infarction (MI). Currently, there exist multiple pathway databases that organize molecular datasets and manually curate pathway maps for biological interpretation at varying forms of organization. However, inconsistencies among different databases in pathway descriptions, frequently due to conflicting results in the literature, can generate incorrect interpretations. Furthermore, although pathway analysis software provides detailed images of interactions among molecules, it does not exhibit how pathways interact with one another or with other biological processes under specific conditions.

Methods

We propose a novel method to standardize descriptions of enriched pathways for a set of genes/proteins using Gene Ontology terms. We used this method to examine the relationships among pathways and biological processes for a set of condition-specific genes/proteins, represented as a functional biological pathway-process network. We applied this algorithm to a set of 613 MI-specific proteins we previously identified.

Results

A total of 96 pathways from Biocarta, KEGG, and Reactome, and 448 Gene Ontology Biological Processes were enriched with these 613 proteins. The pathways were represented as Boolean functions of biological processes, delivering an interactive scheme to organize enriched information with an emphasis on involvement of biological processes in pathways. We extracted a network focusing on MI to demonstrate that tyrosine phosphorylation of Signal Transducer and Activator of Transcription (STAT) protein, positive regulation of collagen metabolic process, coagulation, and positive/negative regulation of blood coagulation have immediate impacts on the MI response.

Conclusions

Our method organized biological processes and pathways in an unbiased approach to provide an intuitive way to identify biological properties of pathways under specific conditions. Pathways from different databases have similar descriptions yet diverse biological processes, indicating variation in their ability to share similar functional characteristics. The coverages of pathways can be expanded with the incorporation of more biological processes, predicting involvement of protein members in pathways. Further, detailed analyses of the functional biological pathway-process network will allow researchers and scientists to explore critical routes in biological systems in the progression of disease.

Tolerability, pharmacokinetics and pharmacodynamics of TA-8995, a selective cholesteryl ester transfer protein (CETP) inhibitor, in healthy subjects

AIMS

Two double-blind, randomized studies were conducted to assess the tolerability, pharmacokinetics and pharmacodynamics of oral TA-8995, a new cholesteryl ester transfer protein (CETP) inhibitor, in healthy subjects.

METHODS

Study 1: Subjects received single doses of TA-8995 or placebo (fasted). Doses were 5, 10, 25, 50 (fed/fasted), 100 and 150 mg (Caucasian males, 18-55 years), 25 mg (Caucasian males, > 65 years and Caucasian females, 18-55 years), 25, 50, 100 and 150 mg (Japanese males, 18-55 years). Study 2: Caucasian males (18-55 years) received 1, 2.5, 10 or 25 mg once daily TA-8995 or placebo for 21-28 days. Blood and urine for pharmacokinetics and/or pharmacodynamics were collected. Tolerability was assessed by adverse events, vital signs, electrocardiograms and laboratory safety tests.

RESULTS

Peak TA-8995 concentrations occurred approximately 4 h post-dose. Mean half-lives ranged from 81 to 166 h, without an obvious dose relationship. Exposure increased less than proportionally to dose. TA-8995 was not excreted in urine. Following 2.5 to 25 mg once daily dosing, TA-8995 demonstrated nearly complete inhibition of CETP activity (92-99%), increased high density lipoprotein-cholesterol (HDL-C) by 96 to 140% and decreased low density liporotein-cholesterol (LDL-C) by 40% to 53%. There were dose-related increases in apolipoproteins A-1 and E, HDL2-C and HDL3-C, and decreases in apolipoprotein B and lipoprotein A. There was no evidence of significant effects of age, gender, ethnicity or food on pharmacokinetics or pharmacodynamics. All doses were well tolerated.

CONCLUSIONS

TA-8995 is a potent CETP inhibitor and warrants further investigation.

Low birthweight and elevated levels of lipoprotein(a) in prepubertal children

AIM

To evaluate whether healthy prepubertal children with low birthweight (LBW) exhibited higher serum levels of lipoprotein(a) (Lp(a)) than did those with normal birthweight (NBW).

METHODS

A total of 350 healthy children aged 6 to 9 years and in Tanner stage 1 were enrolled in a community-based cross-sectional study. Family history of hypertension, diabetes or cardiovascular disease (CVD) in parents and grandparents; active smoking; a diagnosis of acute or chronic illness; and intake of vitamins or nutritional supplements were exclusion criteria. The cut-off point for Lp(a) was 0.79 μmol/L.

RESULTS

LBW was identified in 51 (14.6%) children. In total, 42 (12.0%) children had elevated Lp(a) levels, with 25 (49.0%) and 17 (5.7%) in the LBW and NBW groups, respectively (P < 0.0005). None of the children had adverse cardiovascular outcomes. Average body mass index (BMI) (17.1 ± 3.3 and 18.8 ± 3.9, P = 0.001), glucose levels (4.5 ± 0.5 and 4.8 ± 0.4 mmol/L, P = 0.007), insulin levels (67.4 ± 45.1 and 86.1 ± 54.9 pmol/L, P = 0.02), and Lp(a) levels (0.52 ± 0.21 and 1.40 ± 0.49 μmol/L, P < 0.0005) were higher in the children with LBW than in the children with NBW. A multivariate analysis adjusted by age, sex, raw BMI, BMI standard deviation score and insulin level showed a significant association between LBW and elevated levels of Lp(a) (odds ratio 8.02, 95% confidence interval 7.3-21.3; P < 0.0005).

CONCLUSIONS

LBW was shown to be strongly associated with elevated serum levels of Lp(a).

Lp(a) is not associated with diabetes but affects fibrinolysis and clot structure ex vivo

Lipoprotein (a) [Lp(a)] is a low density lipoprotein (LDL) with one apolipoprotein (a) molecule bound to the apolipoprotein B-100 of LDL. Lp(a) is an independent risk factor for cardiovascular disease (CVD). However, the relationship of Lp(a) to diabetes and metabolic syndrome, both known for increased CVD risk, is controversial. In a population based study on type two diabetes mellitus (T2DM) development in women, Lp(a) plasma levels showed the well known skewed distribution without any relation to diabetes or impaired glucose tolerance. A modified clot lysis assay on a subset of 274 subjects showed significantly increased clot lysis times in T2DM subjects, despite inhibition of PAI-1 and TAFI. Lp(a) plasma levels significantly increased the maximal peak height of the clot lysis curve, indicating a change in clot structure. In this study Lp(a) is not related to the development of T2DM but may affect clot structure ex vivo without a prolongation of the clot lysis time.

The association between circulating lipoprotein(a) and type 2 diabetes: is it causal?

Epidemiological evidence supports a direct and causal association between lipoprotein(a) [Lp(a)] levels and coronary risk, but the nature of the association between Lp(a) levels and risk of type 2 diabetes (T2D) is unclear. In this study, we assessed the association of Lp(a) levels with risk of incident T2D and tested whether Lp(a) levels are causally linked to T2D. We analyzed data on 18,490 participants from the European Prospective Investigation of Cancer (EPIC)-Norfolk cohort that included adults aged 40-79 years at baseline 1993-1997. During an average 10 years of follow-up, 593 participants developed incident T2D. Cox regression models were used to estimate the association between Lp(a) levels and T2D. In Mendelian randomization analyses, based on EPIC-Norfolk combined with DIAbetes Genetics Replication And Meta-analysis data involving a total of 10,088 diabetes case participants and 68,346 control participants, we used a genetic variant (rs10455872) as an instrument to test whether the association between Lp(a) levels and T2D is causal. In adjusted analyses, there was an inverse association between Lp(a) levels and T2D: hazard ratio was 0.63 (95% CI 0.49-0.81; P trend = 0.003) comparing the top versus bottom quintile of Lp(a). In EPIC-Norfolk, a 1-SD increase in logLp(a) was associated with a lower risk of T2D (odds ratio [OR] 0.88 [95% CI: 0.80-0.95]). However, in Mendelian randomization analyses, a 1-SD increase in logLp(a) due to rs10455872, which explained 26.8% of the variability in Lp(a) levels, was not associated with risk of T2D (OR 1.03 [0.96-1.10]; P = 0.41). These prospective findings demonstrate a strong inverse association of Lp(a) levels with risk of T2D. However, a genetic variant that elevated Lp(a) levels was not associated with risk of T2D, suggesting that elevated Lp(a) levels are not causally associated with a lower risk of T2D.

Niacin, an old drug with a new twist

Niacin (nicotinic acid) has been used for decades as a lipid-lowering drug. The clinical use of niacin to treat dyslipidemic conditions is limited by its side effects. Niacin, along with fibrates, are the only approved drugs which elevate high density lipoprotein cholesterol (HDLc) along with its effects on low density lipoprotein cholesterol (LDLc) and triglycerides. Whether niacin has a beneficial role in lowering cardiovascular risk on the background of well-controlled LDLc has not been established. In fact, it remains unclear whether niacin, either in the setting of well-controlled LDLc or in combination with other lipid-lowering agents, confers any therapeutic benefit and if so, by which mechanism. The results of recent trials reject the hypothesis that simply raising HDLc is cardioprotective. However, in the case of the clinical trials, structural limitations of trial design complicate their interpretation. This is also true of the most recent Heart Protection Study 2-Treatment of HDLc to Reduce the Incidence of Vascular Events (HPS2-THRIVE) trial in which niacin is combined with an antagonist of the D prostanoid (DP) receptor. Human genetic studies have also questioned the relationship between cardiovascular benefit and HDLc. It remains to be determined whether niacin may have clinical utility in particular subgroups, such as statin intolerant patients with hypercholesterolemia or those who cannot achieve a sufficient reduction in LDLc. It also is unclear whether a potentially beneficial effect of niacin is confounded by DP antagonism in HPS2-THRIVE.

Cardiovascular disease in women

Gender-specific data focused on cardiovascular disease (CVD) are becoming increasingly available. This is of great importance, given that CVD has become the number 1 killer of women, and unlike for men, mortality rates do not seem to be declining. Many factors are cited as the causes of sex-based differences, including delays in recognizing symptoms, underutilization of diagnostic tests and treatments, as well as anatomic, physiological, and genetic factors. Evidence of fundamental biological differences in vascular function and the underlying pathologic processes is only beginning to elucidated, motivated by growing evidence of differences in clinical presentations and outcomes between men and women. The good news is that we are starting to see improvements in outcomes for women, such as after coronary revascularization; decrease in complication rates with the advent of new techniques, such as radial access for cardiac catheterizations; as well as increased participation of women in clinical trials. The underlying mechanisms of ischemic heart disease remain to be elucidated, and will help guide therapy and ultimately may explain the higher prevalence of : subendocardial myocardial infarctions, spontaneous arterial dissections, plaque erosion, increased vasospastic disorders, such as coronary microvascular disease, and pulmonary hypertension in women compared with men. We have made great progress in understanding gender-related differences in CVDs, but much remains to be done to optimize the prevention of CVD for both men and women.

Myocardial infarction and other co-morbidities in patients with chronic obstructive pulmonary disease: a Danish nationwide study of 7.4 million individuals

AIMS

Myocardial infarction is nominally the most important co-morbidity in patients with chronic obstructive pulmonary disease, and the one with the greatest potential for treatment and prevention to improve the overall prognosis of chronic obstructive pulmonary disease patients. We assessed the extent of myocardial infarction and other co-morbidities in individuals with chronic obstructive pulmonary disease in the general population.

METHODS AND RESULTS

We used individual participant data for the entire Danish population from 1980 through 2006, comprising 140 million person-years of follow-up. We used information from four national Danish registries with 100% follow-up and detected ever-diagnosed chronic obstructive pulmonary disease (n = 313,958) and incident cases of a first myocardial infarction (n = 422,344), lung cancer (n = 116,629), hip fracture (n = 53,756), depression (n = 93 038), and diabetes mellitus (n = 292 228). Multivariate adjusted hazard ratios for life-time association with ever-diagnosed chronic obstructive pulmonary disease were 1.26 (95% CI 1.25-1.27) for myocardial infarction, 2.05 (2.03-2.08) for lung cancer, 2.12 (2.07-2.17) for hip fracture, 1.74 (1.70-1.77) for depression, and 1.21 (1.20-1.23) for diabetes mellitus, compared with controls; these risk estimates were highest in women and the youngest age groups. Before the first hospitalization with chronic obstructive pulmonary disease, multivariate adjusted odds ratios were 1.47 (1.44-1.49) for myocardial infarction, 3.68 (3.52-3.84) for lung cancer, 1.16 (1.13-1.18) for hip fracture, 1.88 (1.80-1.96) for depression, and 1.16 (1.13-1.18) for diabetes mellitus, compared with matched controls. Corresponding values after a chronic obstructive pulmonary disease hospitalization were 0.74 (0.73-0.76), 1.48 (1.45-1.51), 1.23 (1.20-1.27), 1.21 (1.18-1.24), and 0.83 (0.81-0.85), respectively.

CONCLUSION

Chronic obstructive pulmonary disease was associated with higher rates of myocardial infarction, lung cancer, diabetes, hip fracture, and depression, but the strength of these associations was modified after a first admission for chronic obstructive pulmonary disease. These associations may be related to common genetic and/or lifestyle/environmental risk factors, and therefore these factors are likely to have an adverse health impact rather than chronic obstructive pulmonary disease per se.