PCSK9 and Lp(a) levels of children born after assisted reproduction technologies

Vascular function in a cohort of children, adolescents and young adults conceived through assisted reproductive technologies-results from the Munich heARTerY-study

Background

Over 8 million individuals worldwide have been conceived through assisted reproductive technologies (ART). There is conflicting evidence on the cardiovascular health of ART offspring. This study aimed to investigate vascular function in a cohort of children, adolescents and young adults conceived through ART compared to spontaneously conceived peers.

Methods

Anthropometric variables, diet quality, level of physical activity and sedentary behavior were assessed. An extensive evaluation of vascular function was conducted. Blood pressure as well as endothelial function were evaluated. Carotid intima-media thickness was recorded sonographically. Blood draws were taken to determine blood lipids as well as HbA1c.

Results

In total, 66 ART subjects conceived through in vitro fertilization (IVF) or intracytoplasmic sperm injection and 86 spontaneously conceived peers were included in this observational cohort study. Both groups were similar in age [11.31 (8.10-18.00) vs. 11.85 (8.72-18.27) years, P=0.373]. ART subjects displayed a significantly higher body fat percentage [19.30% (15.80-26.02%) vs. 15.91% (13.21-21.00%), P=0.007]. Both groups did not differ significantly in diet quality, physical activity, sedentary behavior, and vascular function. Blood lipids and HbA1c were comparable between both groups. ART subjects showed significantly lower levels of triglycerides compared to spontaneously conceived peers. The prevalence of lipoprotein (a) [Lp(a)] ≥50 mg/dL tended to be higher within the ART cohort. Vascular function did not deteriorate more profoundly with age in ART subjects than in spontaneously conceived peers.

Conclusions

The results of the current study do not indicate a significantly lower vascular function in a cohort of children, adolescents and young adults conceived through ART compared to spontaneously conceived peers. Future studies should address the prevalence of elevated Lp(a) levels in infertile individuals who sought ART treatment. In addition, more studies evaluating body fat percentage as well as cardiovascular morbidity in adult ART subjects are required. For a more precise cardiovascular risk stratification, multi-center studies with larger ART sample sizes, preferably at adult age, are required in the future.

Similar Myocardial Perfusion and Vascular Stiffness in Children and Adolescents with High Lipoprotein (a) Levels, in Comparison with Healthy Controls

Background and Aims

This study investigated the possible correlation between elevated lipoprotein (a) (Lp(a)) levels and early vascular aging biomarkers in healthy children and adolescents.

Methods

Twenty-seven healthy children/adolescents, mean age 9.9 ± 3.7 years, with high Lp(a) levels without other lipid abnormalities and 27 age- and sex-matched controls with normal Lp(a) levels, were included in the study. The investigation of possible early vascular aging was assessed by measuring vascular function indices: carotid intima-media thickness (c-IMT), pulse wave velocity (PWV), augmentation index (AIx), and subendocardial viability ratio (SEVR).

Results

Although serum lipid values were within normal levels, mean values of total cholesterol and apolipoprotein B were higher in the group of children with high Lp(a) levels than controls (p = 0.006 and p < 0.001, respectively). Vascular function indices did not show significant differences, neither between the 2 groups nor in the subgroups of children with increased Lp(a) levels. These subgroups were defined by the presence or absence of family history of premature coronary artery disease. Lp(a) levels did not show a significant correlation with the other parameters studied, both regarding the whole sample (patients and controls), as well as in the subgroups of elevated Lp(a) levels. However, in the group of children with high Lp(a) levels, c-IMT and PWV were positively correlated with diastolic blood pressure (r = 0.427, p = 0.026 and r = 0.425, p = 0.030, respectively), while SEVR was negatively correlated with AIx (r = -0.455, p = 0.017).

Conclusions

Healthy children and adolescents with high Lp(a) levels do not yet have impaired vascular indices, compared to controls. However, in order to prevent early atherosclerosis, it is crucial to early identify and follow up children with high Lp(a) levels and positive family history of premature coronary disease or other cardiovascular risk factors.

PCSK9: Associated with cardiac diseases and their risk factors?

PCSK9 plays a critical role in cholesterol metabolism via the PCSK9-LDLR axis. Liver-derived, circulating PCSK9 has become a novel drug target in lipid-lowering therapy. Accumulative evidence supports the possible association between PCSK9 and cardiac diseases and their risk factors. PCSK9 exerts various effects in the heart independently of LDL-cholesterol regulation. Acute myocardial infarction (AMI) induces local and systemic inflammation and reactive oxygen species generation, resulting in increased PCSK9 expression in hepatocytes and cardiomyocytes. PCSK9 upregulation promotes excessive autophagy and apoptosis in cardiomyocytes, thereby contributing to cardiac insufficiency. PCSK9 might also participate in the pathophysiology of heart failure by regulating fatty acid metabolism and cardiomyocyte contractility. It also promotes platelet activation and coagulation in patients with atrial fibrillation. PCSK9 is an independent predictor of aortic valve calcification and accelerates calcific aortic valve disease by regulating lipoprotein(a) catabolism. Accordingly, the use of PCSK9 inhibitors significantly reduced infarct sizes and arrhythmia and improves cardiac contractile function in a rat model of AMI. Circulating PCSK9 levels are positively correlated with age, diabetes mellitus, obesity, and hypertension. Here, we reviewed recent clinical and experimental studies exploring the association between PCSK9, cardiac diseases, and their related risk factors and aiming to identify possible underlying mechanisms.

PCSK9 in African Americans and Caucasians in Relation to Lp(a) Level, Apo(a) Size and Heritability

Context

Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduces lipoprotein(a) [Lp(a)] levels, but the association of PCSK9 with Lp(a) level and its major determinant, apolipoprotein(a) [apo(a)] size, is not fully understood.

Objective

To assess the relationship between PCSK9, Lp(a) level, apo(a) size, age, and ethnicity/race.

Design

Cross-sectional

Setting

General population

Participants

Healthy African Americans and Caucasians (n = 267); age range: 6 to 74 years.

Interventions

None.

Main outcome measure(s)

PCSK9 levels, apo(a) isoform and LPA allele sizes, and isoform-specific Lp(a) levels.

Results

Plasma PCSK9 levels were significantly higher in African Americans vs Caucasians, in females vs males, and in adults vs children. PCSK9 levels were not associated with total plasma Lp(a) levels either in all participants or in ethnicity-specific analyses. However, PCSK9 levels were significantly positively associated with isoform-specific Lp(a) levels carried by the larger apo(a) size in all participants (r = 0.139, P = 0.0361). In ethnicity/race analyses, a significant association was seen for African Americans (r = 0.268, P = 0.0199), but not for Caucasians. In contrast, there were no significant associations of PCSK9 with isoform-specific Lp(a) levels for the smaller apo(a) sizes in all participants nor in ethnic-specific analyses. Furthermore, heritability (h²) analyses revealed a significant heritability for PCSK9 level in both ethnic groups, with a higher estimate in Caucasians than in African Americans (47% vs 22%, respectively).

Conclusions

Among African Americans, but not Caucasians, PCSK9 levels were associated with isoform-specific Lp(a) levels carried on larger, but not smaller, apo(a) sizes. The findings illustrate a diverging relationship of PCSK9 with isoform-specific Lp(a) levels across ethnicity.

Eligibility for PCSK-9 inhibitors treatment in acute coronary syndrome, chronic coronary artery disease and outpatient dyslipidemic patients

BACKGROUND AND AIMS

We aimed to investigate potential eligibility for proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors in patients with coronary artery disease and dyslipidaemia according to patient characteristics and variable criteria.

METHODS

We prospectively enrolled 2000 patients (acute coronary syndrome = 407, chronic coronary artery disease inpatients = 1087, outpatient Lipid's clinic = 506). To calculate PCSK-9 inhibitors real-world eligibility, a proprietary adjustable software was developed, which stores data and patient characteristics and can determine eligibility depending on different criteria. We tested four scenarios with different LDL thresholds according to ESC/EAS 2016 and 2019 Guidelines, 2017 American College of Cardiology Expert Consensus, and National criteria.

RESULTS

The eligible percentage was 18.85%, 9.75%, 8.55% and 2.15%, in the total population for the four classifications, respectively, and it varied according to clinical status. The increase toward more recent guidelines was mostly attributed to the increasing number of coronary patients who become eligible as our criteria become stricter.

CONCLUSIONS

For the first time, a realistic estimation of PCSK-9 eligibility is provided via an adjustable predictive model in a population of 2000 patients with acute coronary syndrome, chronic coronary artery disease and dyslipidaemia. This can be a valuable tool for the incorporation of PCSK-9 inhibitors in health care systems.

Tauroursodeoxycholic acid (TUDCA) enhanced intracytoplasmic sperm injection (ICSI) embryo developmental competence by ameliorating endoplasmic reticulum (ER) stress and inhibiting apoptosis

PURPOSE

The objective of this study was to examine the effect of tauroursodeoxycholic acid (TUDCA) on intracytoplasmic sperm injection (ICSI) embryos by evaluating endoplasmic reticulum (ER) stress, apoptosis, and embryo developmental competence in vitro and in vivo.

METHODS

ER stress-associated genes and apoptosis-associated genes were measured and apoptosis index was analyzed. Embryo developmental competence was assessed in vitro and in vivo via the inner cell mass (ICM)/trophectoderm (TE) index, pregnancy and implantation rates, and birth rate.

RESULTS

The relative mRNA and protein expression of binding immunoglobulin protein (BIP) was significantly higher in the ICSI embryo group without TUDCA treatment (ICSI-C) than in the in vitro fertilization (IVF) group and in the ICSI embryo group with TUDCA treatment (200 μM) (ICSI-T), while TUDCA ameliorated ER stress in ICSI embryos. Embryos in the ICSI-C group showed a higher apoptosis index than those in the IVF group and ICSI-T group, and there was no significant difference between the IVF group and ICSI-T group. TUDCA can significantly improve ICSI embryo developmental competence in vitro and in vivo based on the ICM/TE index, pregnancy and implantation rates, and birth rate.

CONCLUSION

ICSI embryos manifested high ER stress and high apoptosis, while TUDCA ameliorated ER stress and reduced apoptosis in ICSI embryos. TUDCA can significantly improve the developmental competence of ICSI embryos in vitro and in vivo. This study provides a new idea for improving the efficiency of ICSI, and it will also have a positive effect on the development of assisted reproduction technologies for humans and other animals.