Correlates of serum lipoprotein (A) in children and adolescents in the United States. The third National Health Nutrition and Examination Survey (NHANES-III)

Lipoprotein(a) serum concentrations in children in relation to body mass index, age and sex

BACKGROUND

Lipoprotein(a) (Lp(a)) is an inherited risk factor for atherosclerotic cardiovascular disease (ASCVD). Limited data exist on Lp(a) values in children. We aimed to evaluate whether Lp(a) concentrations in youth are influenced by BMI.

METHODS

756 blood samples of 248 children with obesity and 264 matched healthy children aged 5 and 18 years, enrolled in the population-based LIFE Child (German civilization diseases cohort) study, were analyzed. Repeat measurements were available in 154 children (1-4 follow ups, ~1 year apart).

RESULTS

The median Lp(a) concentration in the total cohort (n = 512) at first visit was 9.7 mg/dL (IQR 4.0-28.3). Lp(a) concentrations between 30-50 mg/dL were observed in 11.5%, while 12.5% exhibited Lp(a) ≧50 mg/dL. There was no association of Lp(a) with body mass index (BMI) (ß = 0.004, P = 0.49). Lp(a) levels did not correlate with age or sex, while Lp(a) was associated positively with low-density lipoprotein cholesterol (ß = 0.05, P < 0.0001). The Lp(a) risk category remained stable in 94% of all children in repeated measurements.

CONCLUSIONS

The data showed no association of Lp(a) levels in children with BMI, age or sex. Measurement of Lp(a) in youth may be useful to identify children at increased lifetime risk for ASCVD.

IMPACT

In youth, Lp(a) levels are not affected by age, sex and BMI. Lp(a) risk categories remain stable over time in repeated measurements in children. Measurement of Lp(a) in children may be useful as an additional factor to identify children at increased lifetime risk for ASCVD and for reverse family screening.

Lipoprotein(a) in Youth and Prediction of Major Cardiovascular Outcomes in Adulthood

BACKGROUND

Elevated lipoprotein(a) [Lp(a)] is a common risk factor for cardiovascular disease outcomes with unknown mechanisms. We examined its potential role in identifying youths who are at increased risk of developing adult atherosclerotic cardiovascular disease (ASCVD).

METHODS

Lp(a) levels measured in youth 9 to 24 years of age were linked to adult ASCVD and carotid intima-media thickness in the YFS (Cardiovascular Risk in Young Finns Study), in which 95 of the original 3596 participants (2.7%) recruited as children have been diagnosed with ASCVD at a median of 47 years of age. Results observed in YFS were replicated with the use of data for White participants from the BHS (Bogalusa Heart Study). In BHS, 587 White individuals had data on youth Lp(a) (measured at 8-17 years of age) and information on adult events, including 15 cases and 572 noncases. Analyses were performed with the use of Cox proportional hazard regression.

RESULTS

In YFS, those who had been exposed to high Lp(a) level in youth [defined as Lp(a) ≥30 mg/dL] had ≈2 times greater risk of developing adult ASCVD compared with nonexposed individuals (hazard ratio, 2.0 [95% CI, 1.4-2.6]). Youth risk factors, including Lp(a), low-density lipoprotein cholesterol, body mass index, and smoking, were all independently associated with higher risk. In BHS, in an age- and sex-adjusted model, White individuals who had been exposed to high Lp(a) had 2.5 times greater risk (95% CI, 0.9-6.8) of developing adult ASCVD compared with nonexposed individuals. When also adjusted for low-density lipoprotein cholesterol and body mass index, the risk associated with high Lp(a) remained unchanged (hazard ratio, 2.4 [95% CI, 0.8-7.3]). In a multivariable model for pooled data, individuals exposed to high Lp(a) had 2.0 times greater risk (95% CI, 1.0-3.7) of developing adult ASCVD compared with nonexposed individuals. No association was detected between youth Lp(a) and adult carotid artery thickness in either cohort or pooled data.

CONCLUSIONS

Elevated Lp(a) level identified in youth is a risk factor for adult atherosclerotic cardiovascular outcomes but not for increased carotid intima-media thickness.

Lipoprotein(a) levels in children with suspected familial hypercholesterolaemia: a cross-sectional study

AIMS

Familial hypercholesterolaemia (FH) predisposes children to the early initiation of atherosclerosis and is preferably diagnosed by DNA analysis. Yet, in many children with a clinical presentation of FH, no mutation is found. Adult data show that high levels of lipoprotein(a) [Lp(a)] may underlie a clinical presentation of FH, as the cholesterol content of Lp(a) is included in conventional LDL cholesterol measurements. As this is limited to adult data, Lp(a) levels in children with and without (clinical) FH were evaluated.

METHODS AND RESULTS

Children were eligible if they visited the paediatric lipid clinic (1989-2020) and if Lp(a) measurement and DNA analysis were performed. In total, 2721 children (mean age: 10.3 years) were included and divided into four groups: 1931 children with definite FH (mutation detected), 290 unaffected siblings/normolipidaemic controls (mutation excluded), 108 children with probable FH (clinical presentation, mutation not detected), and 392 children with probable non-FH (no clinical presentation, mutation not excluded). In children with probable FH, 32% were found to have high Lp(a) [geometric mean (95% confidence interval) of 15.9 (12.3-20.6) mg/dL] compared with 10 and 10% [geometric means (95% confidence interval) of 11.5 (10.9-12.1) mg/dL and 9.8 (8.4-11.3) mg/dL] in children with definite FH (P = 0.017) and unaffected siblings (P = 0.002), respectively.

CONCLUSION

Lp(a) was significantly higher and more frequently elevated in children with probable FH compared with children with definite FH and unaffected siblings, suggesting that high Lp(a) may underlie the clinical presentation of FH when no FH-causing mutation is found. Performing both DNA analysis and measuring Lp(a) in all children suspected of FH is recommended to assess possible LDL cholesterol overestimation related to increased Lp(a).

Pharmacotherapy for children with elevated levels of lipoprotein(a): future directions

INTRODUCTION

Elevated lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). With the advent of the antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs) targeted at LPA, the gene encoding apolipoprotein(a), that are highly effective for lowering Lp(a) levels, this risk factor might be managed in the near future. Given that Lp(a) levels are mostly genetically determined and once elevated, present from early age, we have evaluated future directions for the treatment of children with high Lp(a) levels.

AREAS COVERED

In the current review, we discuss different pharmacological treatments in clinical development and provide an in-depth overview of the effects of ASOs and siRNAs targeted at LPA.

EXPERT OPINION

Since high Lp(a) is an important risk factor for ASCVD and given the promising effects of both ASOs and siRNAs targeted at apo(a), there is an urgent need for well-designed prospective studies to assess the impact of elevated Lp(a) in childhood. If the Lp(a)-hypothesis is confirmed in adults, and also in children, the rationale might arise for treating children with high Lp(a) levels. However, we feel that this should be limited to children with the highest cardiovascular risk including familial hypercholesterolemia and potentially pediatric stroke.

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.

Longitudinal Assessment of Lipoprotein(a) Levels in Perinatally HIV-Infected Children and Adolescents

HIV is an independent risk factor of cardiovascular disease (CVD); therefore, perinatally HIV-infected (PHIV) children potentially have a greater CVD risk at older age. Lipoprotein(a) (Lp(a)) is an established risk factor for CVD in the general population. To evaluate a potential increased CVD risk for PHIV children, we determined their lipid profiles including Lp(a). In the first substudy, we assessed the lipid profiles of 36 PHIV children visiting the outpatient clinic in Amsterdam between 2012 and 2020. In the second substudy, we enrolled 21 PHIV adolescents and 23 controls matched for age, sex and ethnic background on two occasions with a mean follow-up time of 4.6 years. We assessed trends of lipid profiles and their determinants, including patient and disease characteristics, using mixed models. In the first substudy, the majority of PHIV children were Black (92%) with a median age of 8.0y (5.7–10.8) at first assessment. Persistent elevated Lp(a) levels were present in 21/36 (58%) children (median: 374 mg/L (209–747); cut off = 300). In the second substudy, the median age of PHIV adolescents was 17.5y (15.5–20.7) and of matched controls 16.4y (15.8–19.5) at the second assessment. We found comparable lipid profiles between groups. In both studies, increases in LDL-cholesterol and total cholesterol were associated with higher Lp(a) levels. A majority of PHIV children and adolescents exhibited elevated Lp(a) levels, probably associated with ethnic background. Nonetheless, these elevated Lp(a) levels may additionally contribute to an increased CVD risk.

Prevalence and status of Lipoprotein (a) among Lebanese school children

Lipoprotein a (Lp(a) is an independent risk factor for atherosclerotic cardiovascular disease. The prevalence of high Lipoprotein (a) (Lp(a)) in the Lebanese pediatric population is unknown. Our study aims to assess this prevalence and to study the relationship of Lp(a) with the lipid profile, age, body mass index (BMI) and socio-economic status (SES) in Lebanese schoolchildren. A total of 961 children aged 8–18 years (497 boys and 464 girls) were recruited from ten private and public schools in 2013–2014 using a stratified random sample. Schools were selected from the Greater Beirut and Mount Lebanon areas, and were categorized into three subgroups according to the schools’ SES status (high, medium, low). Lp(a) was assayed in 2018 on samples previously frozen at − 80 °C. Abnormal Lp(a) levels (≥ 75 nmol/L) were observed in 14.4% of the overall sample (13.5% for boys,15.3% of girls p = 0.56). The median of Lp(a) was 20(10–50) in the whole sample with no significant gender difference. No significant relationship was found between Lp(a) and age. However, Lp(a) was significantly correlated with BMI in whole sample, as well as in boys and girls (p = 0.02, p = 0.03, p = 0.03, respectively). A significant correlation was found between Lp(a) and non-HDL-C in the whole sample as well as in boys and girls (respectively p < 0.001,p = 0.024 and p = 0.03), but not with triglycerides and HDL-C. In a multivariate linear regression analysis, Lp(a) was only independently associated with BMI and non-HDL-C in boys and girls. Lp(a) was independently associated with BMI and non-HDL-C while no significant relationship was observed with age and sex confirming the strong genetic determination of Lp(a).

Lipoprotein(a) levels and association with myocardial infarction and stroke in a nationally representative cross-sectional US cohort

BACKGROUND

Lipoprotein(a) (Lp(a)) has not been well-studied in a nationally representative US cohort.

OBJECTIVE

The objective of this study was to investigate the distribution of Lp(a) and its associations with nonfatal cardiovascular events in a nationally representative cohort.

METHODS

Cross-sectional analysis using the National Health and Nutrition Examination Survey III cohort (1991-1994). We compared Lp(a) levels across demographics and tested the associations between Lp(a) and patient-reported nonfatal myocardial infarction (MI) and/or stroke using multivariate logistic regression.

RESULTS

Median Lp(a) was 14 mg/dL (interquartile range [IQR]: 3, 32) (n = 8214). 14.7% (95% CI: 13.6%-15.9%) had Lp(a) ≥50 mg/dL. Women had slightly higher median Lp(a) than men (14 mg/dL [IQR: 4, 33] vs 13 [(IQR: 3, 30], P = .001). Non-Hispanics blacks had the highest median Lp(a) (35 mg/dL [IQR: 21, 64]), followed by non-Hispanic whites (12 mg/dL [IQR: 3, 29]) and Mexican Americans (8 mg/dL [IQR:1, 21]). In multivariate analysis, Lp(a) was associated (odds ratio per SD increase [95% CI], P-value) with MI (1.41 [1.14-1.75], P = .001), but not stroke (1.14 [0.91-1.44], P = .26). Lp(a) associated with MI in men (1.52 [1.13-2.04], P = .006), non-Hispanic whites (1.60 [1.27-2.03], P < .001), and Mexican Americans (2.14 [1.29-3.55], P = .003), but not women or non-Hispanic blacks. Lp(a) was not associated with stroke among any subgroups.

CONCLUSION

In a nationally representative US cohort, 1 in 7 had Lp(a) ≥50 mg/dL, the guidelines-recommended threshold to consider Lp(a) a risk enhancing factor. Lp(a) was associated with nonfatal MI but not stroke, although there were differential associations by sex and race/ethnicity. Future nationally representative cohorts should test Lp(a) to get an updated estimation.

Nocturnal blood pressure dipping as a marker of endothelial function and subclinical atherosclerosis in pediatric-onset systemic lupus erythematosus

Background

Loss of the normal nocturnal decline in blood pressure (BP), known as non-dipping, is a potential measure of cardiovascular risk identified by ambulatory blood pressure monitoring (ABPM). We sought to determine whether non-dipping is a useful marker of abnormal vascular function and subclinical atherosclerosis in pediatric-onset systemic lupus erythematosus (pSLE).

Methods

Twenty subjects 9–19 years of age with pSLE underwent ABPM, peripheral endothelial function testing, carotid-femoral pulse wave velocity/analysis for aortic stiffness, and carotid intima-media thickness. We assessed the prevalence of non-dipping and other ABPM abnormalities. Pearson or Spearman rank correlation tests were used to evaluate relationships between nocturnal BP dipping, BP load (% of abnormally elevated BPs over 24-h), and vascular outcome measures.

Results

The majority (75%) of subjects had inactive disease, with mean disease duration of 3.2 years (± 2.1). The prevalence of non-dipping was 50%, which occurred even in the absence of nocturnal or daytime hypertension. Reduced diastolic BP dipping was associated with poorer endothelial function (r 0.5, p = 0.04). Intima-media thickness was significantly greater in subjects with non-dipping (mean standard deviation score of 3.0 vs 1.6, p = 0.02). In contrast, higher systolic and diastolic BP load were associated with increased aortic stiffness (ρ 0.6, p = 0.01 and ρ 0.7, p < 0.01, respectively), but not with endothelial function or intima-media thickness.

Conclusion

In a pSLE cohort with low disease activity, isolated nocturnal BP non-dipping is prevalent and associated with endothelial dysfunction and atherosclerotic changes. In addition to hypertension assessment, ABPM has a promising role in risk stratification and understanding heterogeneous mechanisms of cardiovascular disease in pSLE.

Elevated Lipoprotein(a) in Perinatally HIV-Infected Children Compared With Healthy Ethnicity-Matched Controls

Background

HIV-associated cardiovascular disease (CVD) risk in combination antiretroviral therapy (cART)-treated perinatally HIV-infected patients (PHIV+) remains unknown due to the young age of this population. Lipoprotein(a) (Lp(a)) has been established as an independent causal risk factor for CVD in the general population but has not been well established in the population of PHIV+.

Methods

We cross-sectionally compared lipid profiles, including nonfasting Lp(a), together with total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides between 35 cART-treated PHIV+ children aged 8-18 years and 37 controls who were matched for age, sex, ethnicity, and socioeconomic status. We explored associations between Lp(a) and disease- and treatment-related factors (inflammation, monocyte activation, and vascular), biomarkers, and neuroimaging outcomes using linear regression models.

Results

PHIV+ children had significantly higher levels of Lp(a) compared with controls (median, 43.6 [21.6-82.4] vs 21.8 [16.8-46.6] mg/dL; P = .033). Other lipid levels were comparable between groups. Additional assessment of apolipoprotein B, apolipoprotein CIII, apolipoprotein E, and APOE genotype revealed no significant differences. Higher Lp(a) levels were associated with higher plasma apoB levels and with lower monocyte chemoattractant protein-1 and TG levels in PHIV+ children. Lp(a) was not associated with HIV- or cART-related variables or with neuroimaging outcomes.

Conclusions

cART-treated PHIV+ children appear to have higher levels of Lp(a) compared with ethnicity-matched controls, which may implicate higher CVD risk in this population. Future research should focus on the association between Lp(a) and (sub)clinical CVD measurements in cART-treated PHIV+ patients.

Dutch Trial Register number

NRT4074.

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

PURPOSE

Proprotein convertase subtilisin/kexin type 9 (PCSK9) and lipoprotein (a) (Lp[a]) levels are associated with cardiovascular risk. To investigate PCSK9 and Lp(a) levels of children born after assisted reproduction technologies (ART) compared with naturally conceived (NC) controls.

METHODS

In this exposure-matched cohort study, 73 racial-, sex-, and age-matched children (mean age 98 ± 35 months) of ART (intracytoplasmic sperm injection [ICSI] n = 33, classic in vitro fertilization [IVF] n = 40) and 73 NC children were assessed. Blood lipid profile, including PCSK9 and Lp(a) levels, was measured. Children were grouped according to age (< 8 years, 8-10 years, ≥ 10 years).

RESULTS

In the overall population, PCSK9 levels were related to total cholesterol, low-density lipoprotein, and systolic blood pressure, while Lp(a) levels were related to age, apolipoprotein-B, birth weight, height, waist-to-hip ratio, insulin resistance, insulin, and high-sensitivity C-reactive protein. No significant differences were observed regarding lipid biomarkers between ART and NC children. However, a significant interaction was found between age groups and conception method (p < 0.001) showing that PCSK9 levels increase with age in ART children, while they decline with age in NC offspring. IVF children showed higher levels of adjusted mean Lp(a) than ICSI (13.5 vs. 6.8 mg/dl, p = 0.010) and NC children (12.3 vs. 8.3 mg/dl, p = 0.048).

CONCLUSIONS

We show that PCSK9 levels increase with age in ART children, indicating a gradual deterioration of lipidemic profile that could lead to increased cardiovascular risk. Moreover, our results indicate that ART method may be of importance given that classic IVF is associated with higher levels of Lp(a).

Lipoprotein (a): Examination of Cardiovascular Risk in a Pediatric Referral Population

Atherosclerotic cardiovascular disease (CVD), a leading cause of death globally, has origins in childhood. Major risk factors include family history of premature CVD, dyslipidemia, diabetes mellitus, and hypertension. Lipoprotein (a) [Lp(a)], an inherited lipoprotein, is associated with premature CVD, but its impact on cardiovascular health during childhood is less understood. The objective of the study was to examine the relationship between Lp(a), family history of premature CVD, dyslipidemia, and vascular function and structure in a high-risk pediatric population. This is a single-center, cross-sectional study of 257 children referred to a preventive cardiology clinic. The independent variable, Lp(a), separated children into high-Lp(a) [Lp(a) ≥ 30 mg/dL] and normal-Lp(a) groups [Lp(a) < 30 mg/dL]. Dependent variables included family history of premature CVD; dyslipidemia, defined as low-density lipoprotein cholesterol > 130 mg/dL, high-density lipoprotein cholesterol (HDL-C) < 45 mg/dL, triglycerides (TG) > 100 mg/dL; and vascular changes suggesting early atherosclerosis, as measured by carotid-femoral pulse wave velocity (PWV) and carotid artery intima-media thickness (CIMT). Of the 257 children, 110 (42.8%) had high Lp(a) and 147 (57.2%) had normal Lp(a). There was a higher prevalence of African-American children in the high-Lp(a) group (19.3%) compared to the normal-Lp(a) group (2.1%) (p < 0.001). High Lp(a) was associated with positive family history of premature CVD (p = 0.03), higher-than-optimal HDL-C (p = 0.02), and lower TG (p < 0.001). There was no difference in PWV or CIMT between groups. High Lp(a) in children is associated with family history of premature CVD and is prevalent in African-American children. In children with high Lp(a), promotion of intensive lifestyle modifications is prudent to decrease premature CVD-related morbidity.

Lipoprotein(a): Its relevance to the pediatric population

Lipoprotein(a) (Lp(a)) is a highly atherogenic and heterogeneous lipoprotein that is inherited in an autosomal codominant trait. A unique aspect of this lipoprotein is that it is fully expressed by the first or second year of life in children, a pattern that is distinctly different from other lipoproteins, which typically only reach adult levels after adolescence. Despite decades of research, Lp(a) metabolism is still poorly understood but what is abundantly clear is that it is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). The Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents does not recommend measuring Lp(a) levels as part of routine screening except in youth with an ischemic or hemorrhagic stroke or youth with a parental history of ASCVD not explained by classical risk factors. One of the reasons that both the pediatric and adult guidelines fail to include this lipoprotein as part of routine lipid screening is the absence of data to show that lowering Lp(a) will reduce current or future ASCVD risk independently of low-density lipoprotein cholesterol (LDL-C) lowering. The cholesterol carried by Lp(a) is included in the low-density lipoprotein cholesterol measurement, but a separate test is used to measure the lipoprotein mass and/or cholesterol carried only by Lp(a). Because levels seem to be largely under genetic control, studies of lifestyle modification have been inconclusive although one study in obese children showed a decrease in the Lp(a) level comparable with the favorable effect on other lipids. The most compelling data regarding the importance of Lp(a) in the pediatric population are the increased risk associated with arterial ischemic stroke, a risk that is comparable with that associated with antiphospholipid antibodies or protein C deficiency. Although no specific pharmaceutical treatments are recommended to lower Lp(a) levels in youth, it is vitally important to educate youth and their parents about the excessive risk associated with this lipoprotein and the need to avoid the acquisition of other lifestyle-related risk factors such as smoking, excess weight, and physical inactivity to preserve more ideal cardiovascular health in adulthood.

Lipoprotein (a) and cardiovascular risk factors in children and adolescents

OBJECTIVE:

To review the relationship between lipoprotein (a) [Lp(a)] and other risk factors for cardiovascular disease (CVD) in children and adolescents.

DATA SOURCES:

This systematic review included studies from 2001 to 2011, a ten-year time period. Epidemiological studies with children and/or adolescents published in English, Portuguese or Spanish and fully available online were included. The searches were performed in Science Direct, PubMed/Medline, BVS (Biblioteca Virtual em Saúde) and Cochrane Library databases, using the following combination of key-words: "lipoprotein a" and "cardiovascular diseases" and "obesity".

DATA SYNTHESIS:

Overall, 672 studies were obtained but only seven were included. Some studies assessed the family history for CVD. In all of them, Lp(a) levels were increased in patients with family history for CVD. There was also a positive correlation between Lp(a) and LDL-cholesterol, total cholesterol, and apolipoprotein B levels, suggesting an association between Lp(a) levels and the lipid profile.

CONCLUSIONS:

The evidence that CVD may originate in childhood and adolescence leads to the need for investigating the risk factors during this period in order to propose earlier and possibly more effective interventions to reduce morbidity and mortality rates.

High lipoprotein(a) concentrations are associated with impaired endothelial function in children

OBJECTIVE

To examine the association between familial high lipoprotein(a), or Lp(a), concentrations and endothelial function in children participating in the Special Turku Coronary Risk Factor Intervention Project study.

STUDY DESIGN

Seven-month-old children (n = 1062) with their families were randomized to a risk intervention group or to a control group. The intervention group received individualized dietary counseling to reduce the total cholesterol concentration. Children's Lp(a) and lipid values were measured repeatedly. At age 11 years, children were recruited to an ultrasound study of the flow-mediated dilation (FMD) of the brachial artery. The association between relative peak FMD and Lp(a) concentration was examined in 198 control and 193 intervention group children by linear regression analyses adjusted for sex, total cholesterol concentration, and basal artery diameter. The analyses were made in both the control and intervention groups and in the familial risk children who had a parent with Lp(a) concentration greater than 250 mg/l.

RESULTS

Lp(a) concentrations were similar at age 11 years in the intervention and control groups. In all control children, FMD (%) associated inversely with Lp(a) concentration: (β [%/1000 mg/L] = -3.74, 95% CI [-6.43, -1.45]; P = .007) and in 68 familial risk children (β = -4.92, 95% CI [-8.18, -1.66]; P = .0037). In the intervention group the associations were lacking (P > .5), and FMD in the children with high Lp(a) concentrations (>500 mg/L, n = 12) had no attenuation (P = .027).

CONCLUSIONS

Familial high Lp(a) concentration is associated with attenuated endothelial function. This association may be mitigated by an early lifestyle intervention.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00223600.

Atherosclerotic effects of long-term old and new antiepileptic drugs monotherapy: a cross-sectional comparative study

This work aimed to evaluate the metabolic and atherogenic effects of long-term antiepileptic drugs in a group of Egyptian epileptic patients. Sixty-nine epileptic patients on antiepileptic drug monotherapy for at least 2 years and 34 control subjects were recruited in this study. Patients were divided into 5 subgroups according to antiepileptic drugs used (valproate, carbamazepine, lamotrigine, topiramate, and levetiracetam). Fasting lipid profile (total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol), lipoprotein(a), homocysteine, free thyroxine, thyroid-stimulating hormone, and common carotid artery intima-media thickness were measured for all subjects. Significant higher mean values of low-density lipoprotein cholesterol, low-density lipoprotein / high-density lipoprotein ratio, lipoprotein(a), homocysteine, significantly lower mean value of high-density lipoprotein cholesterol, and significantly larger diameter of common carotid artery intima-media thickness were observed in each drug-treated group versus control group. Our study supports that long-term monotherapy treatment with valproate, carbamazepine, lamotrigine, and topiramate had altered markers of vascular risk that might enhance atherosclerosis, whereas levetiracetam exerted minimal effect.

Lipoprotein(a) in Children of Asian Indian Descendants and Their Caucasian Neighbors: The Slovak Lipid Community Study

To elucidate a higher rate of premature cardiovascular disease (CVD) in Asian Indian descendants (Roma) in Slovakia, we investigated frequency distribution, correlates and relationship of lipoprotein(a) [Lp(a)] to family CVD risk factors in Roma children and their Caucasian neighbors. The study sample consisted of 607 healthy children aged 7-18 years (55% Roma, 48% male) as part of the biracial (Roma-Caucasian) Slovak Lipid Community Study. Overall, frequency distribution data of Lp(a) were highly skewed to low concentrations, with markedly higher Lp(a) levels in Roma than in Caucasian children (median and range, mg/dL: 14.5; 0-159.2 vs 6.2; 0-112.3, P < 0.001), regardless of age and gender. Lp(a) was positively correlated with apo B (0.159, P = 0.004) in Roma, and LDL cholesterol (0.170, P = 0.005) in Caucasian children. In addition, daily income of the family was negatively related with Lp(a) in Roma (-0.134, P = 0.036) while positively in Caucasians (0.136, P = 0.047). For both race groups, no significant association was found between Lp(a) and age, body mass index, mean arterial pressure, smoking, and physical activity. Also, no significant relationships were examined between serum Lp(a) levels >30 mg/dL in children and family CVD risk factors, except for diabetes mellitus in parents of Caucasian origin (OR 4.46; 95%CI: 1.23-16.20). In a multivariate analysis, daily income, LDL cholesterol or apo B explained ~7% of the variance of Lp(a). This study suggests a significantly higher serum Lp(a) levels in Roma than in Caucasian children and a small effect, in general, of relevant CVD risk factors on the variation of Lp(a) levels in childhood.

Lipoprotein(a) concentration does not differ between sexes in healthy offspring of patients with premature myocardial infarction

AIMS

Although a family history of coronary artery disease (CAD) is an established factor influencing lipoprotein(a) [Lp(a)] levels, the effect of sex on Lp(a) concentration remains unclear. A potential cause of the conflicting findings regarding the effect of sex on this novel CAD risk factor is the limited ability of the studies, to date, to adequately control for the potential confounding effect of CAD familial predisposition. Our purpose was to evaluate the influence of sex on Lp(a) concentration in healthy young individuals by controlling for family history of CAD. In order to achieve our goal, we compared Lp(a) levels in pairs of brothers and sisters with a positive parental history of premature myocardial infarction (PHPMI).

METHODS

We measured Lp(a) concentration in 77 healthy brother-sister pairs with PHPMI (mean age: brothers: 18.4 ± 6.2 years and sisters: 18.1 ± 5.8 years). Total cholesterol, low-density lipoprotein (LDL)-cholesterol and high-density lipoprotein (HDL)-cholesterol, triglycerides, apolipoprotein (Apo) A-I and B were also measured.

RESULTS

Lp(a) levels did not differ between siblings of different sex (male vs. female sex: 0.994 ± 1.29 vs. 0.860 ± 0.82 μmol/l, P = 0.940); moreover, the prevalence of elevated (>1.071 μmol/l) Lp(a) concentrations between sexes was the same (29.9%). As expected, compared to female sex, male sex showed higher total/HDL-cholesterol ratio (3.642 ± 0.99 vs. 3.329 ± 0.89, P = 0.017) and lower HDL-cholesterol (1.221 ± 0.24 vs. 1.343 ± 0.28 mmol/l, P = 0.001), Apo A-I (1.390 ± 0.20 vs. 1.474 ± 0.23 g/l, P = 0.003) concentrations and Apo A-I/Apo B ratio (1.632 ± 0.49 vs. 1.830 ± 0.66, P = 0.016).

CONCLUSION

Our results show that healthy young men with PHPMI have a similar Lp(a) levels but worse lipid profile than women.

Laboratory markers of cardiovascular risk in pediatric SLE: the APPLE baseline cohort

As part of the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) Trial, a prospective multicenter cohort of 221 children and adolescents with systemic lupus erythematosus (SLE) (mean age 15.7 years, 83% female) underwent baseline measurement of markers of cardiovascular risk, including fasting levels of high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG), lipoprotein A (Lpa), homocysteine and high-sensitivity C-reactive protein (hs-CRP). A cross-sectional analysis of the baseline laboratory values and clinical characteristics of this cohort was performed. Univariable relationships between the cardiovascular markers of interest and clinical variables were assessed, followed by multivariable linear regression modeling. Mean levels of LDL, HDL, Lpa, TG, hs-CRP and homocysteine were in the normal or borderline ranges. In multivariable analysis, increased Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), prednisone dose, and hypertension (HTN) were independently associated with higher LDL levels. Higher hs-CRP and creatinine clearance were independently related to lower HDL levels. Higher body mass index (BMI), prednisone dose, and homocysteine levels were independently associated with higher TG levels. Only Hispanic or non-White status predicted higher Lpa levels. Proteinuria, higher TG and lower creatinine clearance were independently associated with higher homocysteine levels, while use of multivitamin with folate predicted lower homocysteine levels. Higher BMI, lower HDL, and longer SLE disease duration, but not SLEDAI, were independently associated with higher hs-CRP levels. The R(2) for these models ranged from 7% to 23%. SLE disease activity as measured by the SLEDAI was associated only with higher LDL levels and not with hs-CRP. Markers of renal injury (HTN, proteinuria, and creatinine clearance) were independently associated with levels of LDL, HDL, and homocysteine, highlighting the importance of renal status in the cardiovascular health of children and adolescents with SLE. Future longitudinal analysis of the APPLE cohort is needed to further examine these relationships.

Periodontal pathogens in erupting third molars of periodontally healthy subjects

The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Tannerella forsythensis in bacteriologic samples of 5-7-mm deep mandibular third-molar pericoronal pockets was analysed by polymerase chain reaction, to test the hypothesis that these sites would harbour the bacteria. The patients were periodontally healthy 20-year-old Finnish male conscripts. Sixteen had acute pericoronitis, 28 chronic pericoronitis, and 15 were symptom-free controls. A. actinomycetemcomitans was detected in only 7% of the samples from chronic pericoronitis cases, whereas P. gingivalis was positive in 20% of the symptom-free versus 69% (P = 0.018) of the acute and 57% (P = 0.044) of the chronic cases. The percentages for P. intermedia were 93, 94 and 93%, and for T. forsythensis 47, 63 and 57%, respectively. These results confirm that, apart from A. actinomycetemcomitans, periodontopathogens are common in third-molar sites in periodontally healthy individuals.

Apheresis in Coronary Heart Disease With Elevated Lp (a): A Review of Lp (a) As a Risk Factor and Its Management

Lipoprotein (a) (Lp (a)) increases global cardiovascular risk, especially when LDL cholesterol is concomitantly elevated. Epidemiologic data show that Lp (a) concentration in plasma can be used to predict the risk of early atherogenesis in a dose-dependent manner and late stages of atherosclerosis are accelerated by elevated Lp (a). Therapeutic means to lower Lp (a) are limited. The most effective method to reduce plasma Lp (a) concentration significantly is therapeutic apheresis. Because apheresis is laborious and expensive, patients considered for this procedure should suffer from high Lp (a) concentrations, well beyond 50 mg/dL, and have manifested and progressive coronary heart disease despite maximal drug therapy. Experimental data and therapeutic results will be discussed in the present paper.

Ethnicity and lipoprotein(a) polymorphism in Native Mexican populations

BACKGROUND

Lp(a) is a lipoparticle of unknown function mainly present in primates and humans. It consists of a low-density lipoprotein and apo(a), a polymorphic glycoprotein. Apo(a) shares sequence homology and fibrin binding with plasminogen, inhibiting its fibrinolytic properties. Lp(a) is considered a link between atherosclerosis and thrombosis. Marked inter-ethnic differences in Lp(a) concentration related to the genetic polymorphism of apo(a) have been reported in several populations.

AIM

The study examined the structural and functional features of Lp(a) in three Native Mexican populations (Mayos, Mazahuas and Mayas) and in Mestizo subjects.

METHODS

We determined the plasma concentration of Lp(a) by immunonephelometry, apo(a) isoforms by Western blot, Lp(a) fibrin binding by immuno-enzymatic assay and short tandem repeat (STR) polymorphic marker genetic analysis by capillary electrophoresis.

RESULTS

Mestizos presented the less skewed distribution and the highest median Lp(a) concentration (13.25 mg dL(-1)) relative to Mazahuas (8.2 mg dL(-1)), Mayas (8.25 mg dL(-1)) and Mayos (6.5 mg dL(-1)). Phenotype distribution was different in Mayas and Mazahuas as compared with the Mestizo group. The higher Lp(a) fibrin-binding capacity was found in the Maya population. There was an inverse relationship between the size of apo(a) polymorphs and both Lp(a) levels and Lp(a) fibrin binding.

CONCLUSION

There is evidence of significative differences in Lp(a) plasma concentration and phenotype distribution in the Native Mexican and the Mestizo group.