Lipoprotein particle number and size predict vascular structure and function better than traditional lipids in adolescents and young adults

Use of lipid ratios to predict vascular target organ damage in youth

BACKGROUND

Elevated lipid levels are risk factors for early atherosclerosis. Lipid ratios have emerged as potentially stronger predictors of adverse cardiovascular changes and atherogenic cholesterol. Risk stratification in youth with obesity or type 2 diabetes may be improved by using lipid ratios. We sought to determine if lipid ratios would identify abnormalities in arterial structure and stiffness in adolescents and young adults.

METHODS

A total of 762 youth aged 10-24 years had laboratory, anthropometric, blood pressure, and carotid intima-media thickness and arterial stiffness data collected. Subjects were stratified into tertiles (low, mid, high) of lipid ratios and non-high-density lipoprotein cholesterol (HDL-C). Vascular outcomes by tertile were assessed by analyses of variance. General linear models were constructed for each lipid value and included demographics, risk factors, and vascular measures. Correlations between lipid markers, vascular measures, and low-density lipoprotein (LDL) particle size and number were conducted.

RESULTS

There was a progressive increase in arterial thickness and stiffness across all three lipid ratios and non-HDL-C. The triglyceride to HDL-C (TG/HDL-C) ratio remained an independent predictor of arterial thickness and stiffness after adjusting for other cardiovascular risk factors. TG/HDL-C had the highest correlations with arterial stiffness and small, dense LDL.

CONCLUSIONS

Arterial stiffness is increased in youth with high lipid ratios with TG/HDL-C being the most consistent marker of vascular changes. These data suggest that identification of high TG/HDL-C in these individuals may lead to earlier intervention to prevent atherosclerotic cardiovascular disease.

Exploring the Interactions between Obesity and Diabetes: Implications for Understanding Metabolic Dysregulation in a Saudi Arabian Adult Population

The rising prevalence of obesity in Saudi Arabia is a major contributor to the nation's high levels of cardiometabolic diseases such as type 2 diabetes. To assess the impact of obesity on the diabetic metabolic phenotype presented in young Saudi Arabian adults, participants (n = 289, aged 18-40 years) were recruited and stratified into four groups: healthy weight (BMI 18.5-24.99 kg/m2) with (n = 57) and without diabetes (n = 58) or overweight/obese (BMI > 24.99 kg/m2) with (n = 102) and without diabetes (n = 72). Distinct plasma metabolic phenotypes associated with high BMI and diabetes were identified using nuclear magnetic resonance spectroscopy and ultraperformance liquid chromatography mass spectrometry. Increased plasma glucose and dysregulated lipoproteins were characteristics of obesity in individuals with and without diabetes, but the obesity-associated lipoprotein phenotype was partially masked in individuals with diabetes. Although there was little difference between diabetics and nondiabetics in the global plasma LDL cholesterol and phospholipid concentration, the distribution of lipoprotein particles was altered in diabetics with a shift toward denser and more atherogenic LDL5 and LDL6 particles, which was amplified in the presence of obesity. Further investigation is warranted in larger Middle Eastern populations to explore the dysregulation of metabolism driven by interactions between obesity and diabetes in young adults.

Improvement of lipid and lipoprotein profiles in children and adolescents with cystic fibrosis on CFTR modulator therapy

BACKGROUND

Association of a high-fat diet with increased risks of cardiovascular disease (CVD) and type 2 diabetes, has prompted evaluation of lipids in people with CF (pwCF). However, most evidence on dyslipidemia was published before CF transmembrane conductance regulator (CFTR) modulators became a standard of care. The main goal of this study was to investigate the effect of CFTR modulator therapies on lipid and lipoprotein profiles in children and adolescents with CF.

METHODS

Blood samples were collected from 153 pwCF (10.1 ± 4.7 years of age) and 60 age-matched controls. Most pwCF were pancreatic insufficient on pancreatic enzyme replacement therapy. By the end of the study, 65% of CF participants were on CFTR modulator therapy for >1 month. The results of traditional and advanced lipid testing in pwCF were correlated with clinical and dietary information.

RESULTS

Total cholesterol and low-density lipoprotein (LDL) cholesterol were significantly lower in pwCF compared to non-CF participants. Those not receiving CFTR modulators also had significantly lower high-density lipoprotein (HDL) cholesterol and HDL particle number than controls. Individuals with CF on modulator therapy had significantly higher concentrations of anti-atherogenic HDL cholesterol and HDL particles along with lower levels of atherogenic large very-low density lipoprotein (VLDL) particles, total and small LDL particles, and triglycerides compared to those without CFTR modulator therapy.

CONCLUSION

CFTR modulator therapy has a beneficial effect on dyslipidemia in CF. It remains to be seen if these positive changes translate into decreased CVD risk later in life given the increasing life expectancy in CF.

Lipoprotein profile assessed by 1H NMR, BMI and blood pressure are associated with vascular alterations in children with familial hypercholesterolaemia

BACKGROUND AND AIMS

Children with familial hypercholesterolaemia (FH) have elevated low-density lipoprotein cholesterol (LDL-C) concentrations since birth, which increases the risk of cardiovascular disease in adulthood. Arterial injury and stiffness parameters, including carotid intima media thickness (cIMT), pulse wave velocity (PWV) and distensibility (DIST), can be detected early in childhood. We studied the associations between cIMT, PWV and DIST with the lipoprotein profile assessed by proton nuclear magnetic resonance (1H NMR) and with influential variables such as blood pressure (BP) or body mass index (BMI) in children with FH.

METHODS AND RESULTS

In this cross-sectional study, we included 201 children (96 with FH and 105 non-FH controls). Clinical history, physical examination and standard biochemical studies were performed. FH genetic testing was performed when clinically indicated. Carotid ultrasonography and an advanced lipoprotein profile by 1H NMR were performed. Multivariate and classification methods were used. There were no differences between cIMT, PWV and DIST between FH and non-FH children. FH children presented more total LDL and large, medium and small particles. Small LDL particles, BMI and systolic BP determined the presence of pathological IMT in the FH group. LDL size, high-density lipoproteins and very low-density lipoprotein particles together with blood pressure determined the presence of pathological arterial wall elasticity.

CONCLUSIONS

Alterations in lipoprotein parameters assessed by are associated with early structural and functional arterial characteristics in children with FH. BMI and BP act as boosting factors. Cardiovascular prevention should start early in children with FH, encompassing all components of a healthy lifestyle.

Nuclear magnetic resonance-determined lipoprotein profile and risk of breast cancer: a Mendelian randomization study

PURPOSE

While crudely quantified lipoproteins have been reported to affect the risk of breast cancer, the effects of subclass lipoproteins characterized by particle size, particle number, and lipidomes remain unknown.

METHODS

Utilizing nuclear magnetic resonance-based GWAS of 85 lipoprotein traits, we performed two-sample univariable Mendelian randomization (MR) to evaluate the causal relationship between each trait with breast cancer (Ncase/control = 133,384/113,789) and with its estrogen receptor (ER) subtypes. Then, we applied multivariable MR to investigate the independent effects considering both general and central obesity.

RESULTS

In univariable MR, a heterogeneous effect of subclass high-density lipoproteins (HDL) was observed, in which small HDL traits (ORs ranged from 0.89 to 0.94) were associated with a decreased risk of breast cancer while non-small HDLs traits (OR ranged from 1.04 to 1.08) were associated with an increased risk of breast cancer. Very-low-density lipoproteins (VLDL) traits and serum total triglycerides (TG) were associated with a decreased risk of breast cancer (ORs ranged from 0.88 to 0.94). Similar association patterns were found for ER + subtype. In multivariable MR, only the protective effects of small HDL, VLDL and TG on ER + subtype remained significant.

CONCLUSION

We identified a heterogeneous effect of subclass HDLs and a consistent protective effect of VLDL on breast cancer. Only the effects of small HDL and VLDL on ER + subtype remained robust after controlling for obesity. These findings provide new insight into the causal pathway underlying lipoproteins and breast cancer.

Can Surrogate Markers Help Define Cardiovascular Disease in Youth?

PURPOSE OF REVIEW

Non-invasive measurements such as arterial stiffness serve as proxy surrogates for detection of early atherosclerosis and ASCVD risk stratification. These surrogate measurements are influenced by age, gender, and ethnicity and affected by the physiological changes of puberty and somatic growth in children and adolescents.

RECENT FINDINGS

There is no consensus of the ideal method to measure surrogate markers in youth (< 18 years of age), nor standardized imaging protocols for youth. Currently, pediatric normative data are available but not generalizable. In this review, we provide rationale on how currently used surrogates can help identify subclinical atherosclerosis in youth and affirm their role in identifying youth at risk for premature CVD.

HDL Function and Size in Patients with On-Target LDL Plasma Levels and a First-Onset ACS

Patients admitted for acute coronary syndrome (ACS) usually have high cardiovascular risk scores with low levels of high-density lipoprotein cholesterol (HDL-C) and high low-density lipoprotein cholesterol (LDL-C) levels. Here, we investigated the role of lipoprotein functionality as well as particle number and size in patients with a first-onset ACS with on-target LDL-C levels. Ninety-seven patients with chest pain and first-onset ACS with LDL-C levels of 100 ± 4 mg/dL and non-HDL-C levels of 128 ± 4.0 mg/dL were included in the study. Patients were categorized as ACS and non-ACS after all diagnostic tests were performed (electrocardiogram, echocardiogram, troponin levels and angiography) on admission. HDL-C and LDL-C functionality and particle number/size by nuclear magnetic resonance (NMR) were blindly investigated. A group of matched healthy volunteers (n = 31) was included as a reference for these novel laboratory variables. LDL susceptibility to oxidation was higher and HDL-antioxidant capacity lower in the ACS patients than in the non-ACS individuals. ACS patients had lower HDL-C and Apolipoprotein A-I levels than non-ACS patients despite the same prevalence of classical cardiovascular risk factors. Cholesterol efflux potential was impaired only in the ACS patients. ACS-STEMI (Acute Coronary Syndrome—ST-segment-elevation myocardial infarction) patients, had a larger HDL particle diameter than non-ACS individuals (8.4 ± 0.02 vs. 8.3 ± 0.02 and, ANOVA test, p = 0.004). In conclusion, patients admitted for chest pain with a first-onset ACS and on-target lipid levels had impaired lipoprotein functionality and NMR measured larger HDL particles. This study shows the relevance of HDL functionality rather than HDL-C concentration in ACS patients.

Effects of a yoga-based stress reduction intervention on stress, psychological outcomes and cardiometabolic biomarkers in cancer caregivers: A randomized controlled trial

Caregiving stress is a risk factor for cardiometabolic disease. Therefore, integrating cardiometabolic biomarkers into caregiving research provides a more comprehensive assessment of an individual’s health and response to an intervention. The objective of this study was to examine the effects of a yoga-based stress reduction intervention on stress, psychological outcomes, and cardiometabolic biomarkers in cancer caregivers. This prospective randomized controlled trial enrolled family caregivers of adult patients who underwent an allogeneic HSCT at the National Institutes of Health (NIH) Clinical Center. All subjects received usual care education. Participants in the intervention group received an Iyengar yoga intervention self-administered over six weeks using an audio recording file. The primary outcome was perceived stress (measured using the NIH toolbox Perceived Stress). The secondary outcomes were psychological factors (depression and anxiety measured using PROMIS® Depression and Anxiety), and cardiometabolic biomarkers measured by nuclear magnetic resonance spectroscopy. A total of 50 family caregivers (mean [SD] age, 44.9 [15.2] years; 42 [84.0%] women) were randomized, 25 to the intervention group and 25 to the control group. No group differences were noted in stress, depression, and anxiety. Significant interaction effects between group and time were found in large TRL-P (F(1,43) = 10.16, p = 0.003) and LP-IR (F(1,42) = 4.28, p = 0.045). Post-hoc analyses revealed that the levels of large TRL-P (mean difference = 1.68, CI = [0.86, 2.51], p< .001) and LP-IR (mean difference = 5.67, CI = [1.15, 10.18], p = 0.015) significantly increased over time in the control group but while remained stable in the intervention group (mean difference = -0.15, CI = [-0.96, 0.66], p = 0.718; mean difference = -0.81, CI = [-5.22, 3.61], p = 0.714, respectively). Even when perceptions of psychological distress remain unchanged, incorporating gentle yoga poses and breathing exercises may reduce the risk of cardiometabolic disease in caregivers by inhibiting the development of insulin resistance. Standard lipids of cardiometabolic risk do not appear to be robust enough to detect short-term early changes of cardiometabolic risk in caregivers.

Trial registration: ClinicalTrials.gov Identifier: NCT02257853.

The Detection, Evaluation, and Management of Dyslipidemia in Children and Adolescents: A Canadian Cardiovascular Society/Canadian Pediatric Cardiology Association Clinical Practice Update

Atherosclerosis begins in youth and is directly linked with the presence and severity of cardiovascular risk factors, including dyslipidemia. Thus, the timely identification and management of dyslipidemia in childhood might slow atherosclerotic progression and decrease the risk of cardiovascular disease in adulthood. This is particularly true for children with genetic disorders resulting in marked dyslipidemia, including familial hypercholesterolemia, which remains frequently undiagnosed. Universal and cascade screening strategies can effectively identify cases of pediatric dyslipidemia. In the clinical evaluation of children with dyslipidemia, evaluating for secondary causes of dyslipidemia, including medications and systemic disorders is essential. The first line therapy generally centres around lifestyle modifications, with dietary changes specific to the dyslipidemia phenotype. Indications for medication depend on the severity of dyslipidemia and an individualized assessment of cardiovascular risk. Despite an expanding evidence base supporting the detection and timely management of pediatric dyslipidemia, numerous knowledge gaps remain, including a sufficient evidence base to support more widespread screening, thresholds for initiation of pharmacotherapy, and treatment targets. Further studies on the most appropriate age for statin initiation and long-term safety studies of statin use in youth are also required. The most pressing matter, however, is the development of knowledge translation strategies to improve the screening and detection of lipid disorders in Canadian youth.

The Relationship Between Lipoproteins and Insulin Sensitivity in Youth With Obesity and Abnormal Glucose Tolerance

CONTEXT

Youth with obesity and abnormal glucose tolerance have an increased risk for atherosclerosis but the relative contributions of insulin resistance and hyperglycemia to dyslipidemia and the development of subclinical atherosclerosis are unknown.

OBJECTIVE

This work aims to determine the association between insulin resistance, dyslipidemia, and carotid intimal thickness (cIMT) in adolescents with normal and abnormal glucose tolerance.

METHODS

An observational cohort study in 155 youth: 44 obese insulin sensitive (OIS; fasting insulin ≤ 20 µM/mL, body mass index [BMI] ≥ 95th percentile), 35 obese insulin resistant (OIR; fasting insulin > 20 µM/mL, BMI ≥ 95th percentile), 34 obese abnormal glucose tolerant (AGT; BMI ≥ 95th percentile), and 42 Lean (BMI 5th-85th percentile). Lipids, lipoprotein particle size and concentration (-P), insulin sensitivity (SI an intravenous glucose test), and CMIT were compared using linear models adjusted for age, race/ethnicity, biological sex, and Tanner stage. Lipid/lipoprotein profile and CMIT were reevaluated in a subset after 2 years.

RESULTS

Compared to OIS and Lean, OIR and AGT had elevated triglycerides and low high-density lipoprotein cholesterol (HDL-C) but similar total cholesterol and low-density lipoprotein cholesterol (LDL-C). Among OIS, OIR, AGT, lower SI was associated with atherogenic lipids (higher triglycerides, LDL-C, non-HDL-C, and lower HDL-C) and lipoproteins (higher total LDL-P and small HDL-P, and lower large HDL-P). There was a steeper decline in the association of SI with HDL-C and large HDL-P in AGT compared with OIR and OIS. cIMT was comparable across groups and inversely correlated with SI, with no change after 2 years.

CONCLUSION

Among youth with obesity, insulin resistance was associated with an atherogenic lipoprotein/lipid profile and cIMT, regardless of glucose tolerance status. Insulin resistance in AGT youth was associated with a shift to smaller HDL-P compared to normoglycemic youth with obesity. Alterations in HDL-P metabolism may be early adverse manifestations of hyperglycemia in youth with obesity.

Different profiles of lipoprotein particles associate various degrees of cardiac involvement in adolescents with morbid obesity

INTRODUCTION

Dyslipidemia secondary to obesity is a risk factor related to cardiovascular disease events, however a pathological conventional lipid profile (CLP) is infrequently found in obese children. The objective is to evaluate the advanced lipoprotein testing (ALT) and its relationship with cardiac changes, metabolic syndrome (MS) and inflammatory markers in a population of morbidly obese adolescents with normal CLP and without type 2 diabetes mellitus, the most common scenario in obese adolescents.

METHODS

Prospective case-control research of 42 morbidly obese adolescents and 25 normal-weight adolescents, whose left ventricle (LV) morphology and function had been assessed. The ALT was obtained by proton nuclear magnetic resonance spectroscopy, and the results were compared according to the degree of cardiac involvement - normal heart, mild LV changes, and severe LV changes (specifically LV remodeling and systolic dysfunction) - and related to inflammation markers [highly-sensitive C-reactive protein and glycoprotein A (GlycA)] and insulin-resistance [homeostatic model assessment for insulin-resistance (HOMA-IR)]. A second analysis was performed to compare our results with the predominant ALT when only body mass index and metabolic syndrome criteria were considered.

RESULTS

The three cardiac involvement groups showed significant increases in HOMA-IR, inflammatory markers and ALT ratio LDL-P/HDL-P (40.0 vs. 43.9 vs. 47.1, p 0.012). When only cardiac change groups were considered, differences in small LDL-P (565.0 vs. 625.1 nmol/L, p 0.070), VLDL size and GlycA demonstrated better utility than just traditional risk factors to predict which subjects could present severe LV changes [AUC: 0.79 (95% CI: 0.54-1)]. In the second analysis, an atherosclerotic ALT was detected in morbidly obese subjects, characterized by a significant increase in large VLDL-P, small LDL-P, ratio LDL-P/HDL-P and ratio HDL-TG/HDL-C. Subjects with criteria for MS presented overall worse ALT (specially in triglyceride-enriched particles) and remnant cholesterol values.

CONCLUSIONS

ALT parameters and GlycA appear to be more reliable indicators of cardiac change severity than traditional CV risk factors. Particularly, the overage of LDL-P compared to HDL-P and the increase in small LDL-P with cholesterol-depleted LDL particles appear to be the key ALT's parameters involved in LV changes. Morbidly obese adolescents show an atherosclerotic ALT and those with MS present worse ALT values.

Caregiving stress and burden associated with cardiometabolic risk in family caregivers of individuals with cancer

Chronic stress is a well-established risk factor for cardiometabolic disease. Caregiving for individuals with cancer is perceived as a chronic stressor yet research on the risk for cardiometabolic disease in this population, opposed to the elderly and those with Alzheimer's disease, is limited. Additionally, few studies have explored the early physiological changes that occur in family caregivers suggesting an elevated risk for illness. This cross-sectional study was designed to examine levels of cardiometabolic risk biomarkers and their correlates in caregivers of patients with colorectal cancer. Caregivers completed questionnaires that measure exposures to stress and vulnerability factors, psychological distress, and health habits as potential correlates. Traditional lipid and nontraditional lipoprotein particle biomarkers (e.g. concentration and size for all lipoprotein classes) were assayed from blood serum. Caregivers (N = 83, mean age = 49.8, 73% female) displayed levels of cardiometabolic biomarkers that suggest an elevated risk for cardiometabolic disease. Caregivers who were Hispanic, married, highly educated, employed, reported more hours spent caregiving daily, experienced higher caregiver burden associated with the lack of family support and impact on schedule, and psychological distress, demonstrated an elevated risk for cardiometabolic disease; primarily determined by nontraditional lipid biomarkers - large TRL-P, LDL-P, small HDL-P, large HDL-P, TRL-Z, LDL-Z and HDL-Z. These findings suggest that traditional lipid biomarkers may not be robust enough to detect early physiological changes associated with cardiometabolic disease risk in family caregivers. Moreover, findings reiterate the importance of assessing caregiver burden and providing evidence-based interventions to manage caregiving stress with the potential to improve caregivers' cardiometabolic health.

Lipoprotein-subclass particle numbers in children with abdominal obesity

BACKGROUND

The lipoprotein particle number (PN) profile may be a better marker of cardiovascular risks than standard serum lipid measurements. The aim of this study was to analyze the lipoprotein PNs in Japanese children with abdominal obesity and to determine the subclass profile.

METHODS

The participants included 164 Japanese children (79 boys and 85 girls) aged 9-13 years. We obtained waist-to-height ratios (WHtR) and serum lipids for all participants. The lipoprotein PNs in 12 subclasses were analyzed using high performance liquid chromatography (HPLC).

RESULTS

Both boys and girls with abdominal obesity (WHtR ≧ 0.5) had significantly higher triglyceride (TG), very-low-density lipoprotein (VLDL)-PN, and all VLDL-subclass PNs compared to those without abdominal obesity. In boys with abdominal obesity, low-density lipoprotein (LDL)-PN was higher, but lipoprotein cholesterol (LDL-C) was not, and high-density lipoprotein cholesterol (HDL-C) was lower, but HDL-PN was not compared to those without abdominal obesity. In girls with abdominal obesity, LDL-C and LDL-PN were not significantly different and both HDL-C and HDL-PN were lower compared to those without abdominal obesity. Subclass analyses demonstrated that boys and girls with abdominal obesity had significantly lower very large and large HDL-PNs than those without abdominal obesity. In addition, medium, small, and very small LDL-PNs were higher in boys with abdominal obesity than those without abdominal obesity.

CONCLUSIONS

This study found that Japanese children with abdominal obesity are affected by the lipoprotein-subclass PN profile, with sex differences in the LDL- and HDL-subclasses, which is different from results obtained by standard serum lipid measurements.

Direct and indirect effects of obesity on progression of carotid arterial injury in youth

OBJECTIVE

Increased carotid intima-media thickness (cIMT) is associated with cardiovascular (CV) events in adults and with elevated CV risk factors in youth. The aim of this study was to determine whether obesity has an direct or indirect association with cIMT.

METHODS

Structural equation modeling was used to elucidate pathways for obesity to change cIMT. Complete data were collected twice on 294 participants (mean age 17.5 years, 16% with type 2 diabetes). Latent baseline and follow-up cIMT, BMI, and CV risk factors were analyzed with SAS 9.4. Model fit was assessed.

RESULTS

There were increases in BMI, mean arterial pressure (MAP), low-density lipoprotein cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, C-reactive protein, and glucose and a decrease in insulin and glycosylated hemoglobin over 5 years (all p < 0.05). Only bulb (0.031 mm) and internal (0.027 mm) cIMT increased (all p < 0.001). Significant direct effects on cIMT change were baseline MAP (β 0.23), BMI z score (β 0.16), change in glucose (β 0.37), and age (β 0.37; all p < 0.05). Change in MAP showed a trend (β 0.14, p = 0.10). BMI also had a significant indirect effect (β 0.17), whereas non-HDL demonstrated no significant effect.

CONCLUSIONS

Baseline adiposity drives increasing blood pressure and glucose in high-risk youth leading to accelerated accumulation of carotid arterial injury. Prevention of acquisition of obesity in youth is critical in slowing development of CV disease.

Dyslipidemia Is Negatively Associated With the Cumulative Live-Birth Rate in Patients Without PCOS Following IVF/ICSI

Objective: To evaluate the effect of dyslipidemia on the cumulative live-birth rate (cLBR) in patients without polycystic ovary syndrome (PCOS) undergoing in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) cycles. Methods: A total of 1,132 patients from the Yantai Yuhuangding Hospital Affiliated to Qingdao University from January 2016 to December 2017 were retrospectively included. The subjects were distributed into two groups based on their lipid profiles, namely, dyslipidemia group (n = 195) and control group (n = 937). The clinical and laboratory parameters of the two groups were analyzed, and a multivariate logistic regression analysis of the cLBR was conducted. In addition, subgroup analysis was carried out to avoid deviation according to the body mass index (BMI). Results: Patients with dyslipidemia had significantly greater BMI and longer duration of infertility, as well as lower antral follicle count and basal follicle-stimulating hormone level compared with patients without dyslipidemia. Stratified analysis showed that dyslipidemia was associated with a significantly higher total gonadotrophin dosage required for ovarian stimulation as well as lower number of oocytes retrieved, independent of obesity. The live-birth rate in fresh cycle and cLBR were higher in the control group, although the difference between the groups was not significant (54.9% vs. 47.3%, p = 0.116; 67.6% vs. 62.1%, p = 0.138). However, multivariate logistic regression analysis adjusting for potential confounders showed that dyslipidemia was negatively associated with cLBR (OR, 0.702, 95% CI, 0.533-0.881, p = 0.044). Conclusion: Our findings demonstrate for the first time that dyslipidemia has a deleterious impact on cLBR, independent of obesity, in non-PCOS population considered to have good prognosis. Assessment of serum lipid profiles as well as the provision of nutritional counseling is essential for increasing successful outcomes in assisted reproductive techniques.

Pregnancy is accompanied by larger high density lipoprotein particles and compositionally distinct subspecies

Pregnancy is accompanied by significant physiological changes, which can impact the health and development of the fetus and mother. Pregnancy-induced changes in plasma lipoproteins are well documented, with modest to no impact observed on the generic measure of high density lipoprotein (HDL) cholesterol. However, the impact of pregnancy on the concentration and composition of HDL subspecies has not been examined in depth. In this prospective study, we collected plasma from 24 nonpregnant and 19 pregnant women in their second trimester. Using nuclear magnetic resonance (NMR), we quantified 11 different lipoprotein subspecies from plasma by size, including three in the HDL class. We observed an increase in the number of larger HDL particles in pregnant women, which were confirmed by tracking phospholipids across lipoproteins using high-resolution gel-filtration chromatography. Using liquid chromatography-mass spectrometry (LC-MS), we identified 87 lipid-associated proteins across size-speciated fractions. We report drastic shifts in multiple protein clusters across different HDL size fractions in pregnant females compared with nonpregnant controls that have major implications on HDL function. These findings significantly elevate our understanding of how changes in lipoprotein metabolism during pregnancy could impact the health of both the fetus and the mother.

Biomarker Discovery in Atherosclerotic Diseases Using Quantitative Nuclear Magnetic Resonance Metabolomics

Despite great progress in the management of atherosclerosis (AS), its subsequent cardiovascular disease (CVD) remains the leading cause of morbidity and mortality. This is probably due to insufficient risk detection using routine lipid testing; thus, there is a need for more effective approaches relying on new biomarkers. Quantitative nuclear magnetic resonance (qNMR) metabolomics is able to phenotype holistic metabolic changes, with a unique advantage in regard to quantifying lipid-protein complexes. The rapidly increasing literature has indicated that qNMR-based lipoprotein particle number, particle size, lipid components, and some molecular metabolites can provide deeper insight into atherogenic diseases and could serve as novel promising determinants. Therefore, this article aims to offer an updated review of the qNMR biomarkers of AS and CVD found in epidemiological studies, with a special emphasis on lipoprotein-related parameters. As more researches are performed, we can envision more qNMR metabolite biomarkers being successfully translated into daily clinical practice to enhance the prevention, detection and intervention of atherosclerotic diseases.

Characterization of Particle Size Distribution of Plasma Lipoproteins in Dairy Cattle Using High-Resolution Polyacrylamide Electrophoresis

Plasma lipoproteins play critical roles in energy metabolism and inflammation. Concentrations of high-density lipoproteins (HDL) are linked to reproductive outcomes and milk yields in dairy cattle. Low-density lipoproteins (LDL), which are enzymatically formed in the blood from very low-density lipoproteins (VLDL) following secretion by the liver, have been used as a surrogate marker of liver function due to the rapid influx of circulating VLDL into the lactating mammary gland. In humans, the composition of plasma lipoproteins is reflected in lipoprotein particle size distribution, and both of these parameters are highly predictive of disease development and related health outcomes. Bovine HDL are overall larger, less dense particles compared to human HDL. Lipoprotein particle size distribution in both health and disease is understudied in the bovine. We hypothesize that a more detailed analysis of lipoproteins could hold diagnostic and/or prognostic value in the study of dairy cattle health and production. In this study, we took the first steps in this characterization and used a high-resolution polyacrylamide gel electrophoretic assay to better define LDL and HDL at the subfraction level in Holstein cows at different stages of lactation. We extensively characterized the lipoprotein particle size distribution in healthy lactating dairy cattle. We identified subfractions of LDL that were prominent only in the dry period and subfractions of HDL that were highest in cows during mid-lactation. Use of this method could be informative in the study of multiple herds and management strategies, including longitudinal evaluation of animals and production parameters.

Physicochemical Properties of Lipoproteins Assessed by Nuclear Magnetic Resonance as a Predictor of Premature Cardiovascular Disease. PRESARV-SEA Study

Some lipoprotein disorders related to the residual risk of premature cardiovascular disease (PCVD) are not detected by the conventional lipid profile. In this case-control study, the predictive power of PCVD of serum sdLDL-C, measured using a lipoprotein precipitation method, and of the physicochemical properties of serum lipoproteins, analyzed by nuclear magnetic resonance (NMR) techniques, were evaluated. We studied a group of patients with a first PCVD event (n = 125) and a group of control subjects (n = 190). Conventional lipid profile, the size and number of Very Low Density Lipoproteins (VLDL), Low Density Lipoproteins (LDL), High Density Lipoproteins (HDL) particles, and the number of particles of their subclasses (large, medium, and small) were measured. Compared to controls, PCVD patients had lower concentrations of all LDL particles, and smaller and larger diameter of LDL and HDL particles, respectively. PCVD patients also showed higher concentrations of small dense LDL-cholesterol (sdLDL), and triglycerides (Tg) in LDL and HDL particles (HDL-Tg), and higher concentrations of large VLDL particles. Multivariate logistic regression showed that sdLDL-C, HDL-Tg, and large concentrations of LDL particles were the most powerful predictors of PCVD. A strong relationship was observed between increased HDL-Tg concentrations and PCVD. This study demonstrates that beyond the conventional lipid profile, PCVD patients have other atherogenic lipoprotein alterations that are detected by magnetic resonance imaging (MRI) analysis.

Lipid Metabolic Disorders and Ovarian Hyperstimulation Syndrome: A Retrospective Analysis

OBJECTIVES

To evaluate the effect of dyslipidemia on the incidence of moderate and severe Ovarian hyperstimulation syndrome (OHSS) in the duration of assisted reproduction technique (ART).

METHODS

The study included 233 moderate and severe OHSS patients who received hospitalization after in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles to avoid severe complications. They were divided into dyslipidemia group and normal lipid metabolism group to evaluate whether dyslipidemia contributes to the development of severe OHSS. Subgroup analysis was set to avoid deviation including the freeze-all group and fresh embryo transfer (ET) group according to whether the eligible women chose fresh embryo transfer immediately after their IVF or ICSI cycles. The main outcome measures included the incidence of moderate OHSS and severe OHSS, total gonadotropin dose, number of oocytes retrieved, age and body mass index (BMI). In the ET groups, the rate of pregnancy is also included for analysis.

RESULTS

In the freeze-all group, lipid metabolism was ultimately identified as the factor affecting the morbidity of severe OHSS and the ones with dyslipidemia were more likely to develop to severe OHSS (P < 0.05), while the incidence of severe OHSS among the ET groups had no statistical significance (P > 0.05).

CONCLUSION

The findings of this study suggested that dyslipidemia might contribute to the development of OHSS, especially for those patients who chose the cryopreservation of all embryos. It is essential to consider the risk of OHSS in patients with dyslipidemia although they required cryopreservation of all embryos.

Dyslipidemia in Pediatric Type 2 Diabetes Mellitus

PURPOSE OF REVIEW

Cardiovascular (CV) disease is a major cause of mortality in type 2 diabetes mellitus (T2D). Dyslipidemia is prevalent in children with T2D and is a known risk factor for CVD. In this review, we critically examine the epidemiology, pathophysiology, and recommendations for dyslipidemia management in pediatric T2D.

RECENT FINDINGS

Dyslipidemia is multifactorial and related to poor glycemic control, insulin resistance, inflammation, and genetic susceptibility. Current guidelines recommend lipid screening after achieving glycemic control and annually thereafter. The desired lipid goals are low-density lipoprotein cholesterol (LDL-C) < 100 mg/dL, high-density lipoprotein cholesterol (HDL-C) > 35 mg/dL, and triglycerides (TG) < 150 mg/dL. If LDL-C remains > 130 mg/dL after 6 months, statins are recommended with a treatment goal of < 100 mg/dL. If fasting TG are > 400 mg/dL or non-fasting TG are > 1000 mg/dL, fibrates are recommended. Although abnormal levels of atherogenic TG-rich lipoproteins, apolipoprotein B, and non-HDL-C are commonly present in pediatric T2D, their measurement is not currently considered in risk assessment or management.

Consensus document of an expert group from the Spanish Society of Arteriosclerosis (SEA) on the clinical use of nuclear magnetic resonance to assess lipoprotein metabolism (Liposcale®)

The assessment and prevention of cardiovascular risk (CVR) that persists in patients with dyslipidaemia despite treatment and achievement of goals specific to the plasma concentration of cholesterol linked to low density (c-LDL) is a clinical challenge today, and suggests that conventional lipid biomarkers are insufficient for an accurate assessment of CVR. Apart from their lipid content, there are other lipid particle characteristics. The results of this study show that there are a number of lipoprotein compounds that determine atherogenic potential and its influence on the CVR. However, such additional characteristics cannot be analysed by the techniques commonly used in clinical laboratories. Nuclear Magnetic Resonance (NMR) is a technique that allows a detailed analysis to be made of the amount, composition, and size of lipoproteins, as well as providing more information about the detailed status of lipid metabolism and CVR in dyslipidaemia patients. In this article a group of lipidologists from the Spanish Society of Arteriosclerosis review the existing evidence on the atherogenic mechanisms of particles and describe the technical basis and interpretation of the profiles lipoproteins obtained by MRI, with special reference to the test available in Spain (Liposcale®). Likewise, the main patient profiles are defined as such that an analysis would provide information of greater clinical interest. These include: a) Suspected mismatch between lipid concentrations and particles, a common situation in diabetes, obesity, metabolic syndrome; b) Early atherothrombotic cardiovascular disease (ECVA) or recurrent without CVR factors to justify it; c) Lipid disorders, rare or complex, such as extreme concentrations of c-HDL, and d) Clinical situations where classical analytical techniques cannot be applied, such as very low c-LDL values.

Postprandial Dyslipidemia, Hyperinsulinemia, and Impaired Gut Peptides/Bile Acids in Adolescents with Obesity

BACKGROUND

With increased rates of obesity and insulin resistance in youth, development of postprandial dyslipidemia, an important cardiovascular disease risk factor, is a concern. Glucagon-like peptides (ie, GLP-1 and GLP-2) and bile acids have been shown to regulate dietary fat absorption and postprandial lipids in animal models and humans. We hypothesize that the physiological response of GLPs and bile acids to dietary fat ingestion is impaired in adolescents with obesity and this associates with marked postprandial dyslipidemia and insulin resistance.

METHODS

In this cross-sectional study, normal weight adolescents and adolescents with obesity underwent a 6-hour oral fat tolerance test. The postprandial lipoprotein phenotype profile was determined using various assays, including nuclear magnetic resonance spectroscopy, to characterize lipoprotein particle number, size, lipid content, and apolipoproteins. GLP-1 and GLP-2 were quantified by electrochemiluminescent immunoassays. Total bile acids were measured by an automated enzymatic cycling colorimetric method and the bile acid profile by mass spectrometry.

RESULTS

Adolescents with obesity exhibited fasting and postprandial dyslipidemia, particularly augmented postprandial excursion of large triglyceride-rich lipoproteins. Postprandial GLPs were reduced and inversely correlated with postprandial dyslipidemia and insulin resistance. Postprandial bile acids were also diminished, particularly lithocholic acid, a potent stimulator of GLP-1 secretion.

CONCLUSION

Blunted postprandial GLP and bile acid response to dietary fat ingestion strongly associates with marked postprandial dyslipidemia. Further investigation is needed to assess their potential utility as early biomarkers for postprandial dyslipidemia in adolescents with obesity.

Postprandial dyslipidemia in insulin resistant states in adolescent populations

Obesity and the metabolic syndrome are becoming increasingly prevalent not only in adults, but also in adolescents. The metabolic syndrome, a complex cluster of metabolic abnormalities, increases one's risk of developing type 2 diabetes and cardiovascular disease (CVD). Dyslipidemia, a key component of the metabolic syndrome, is highly associated with insulin resistance and contributes to increased CVD risk. Dyslipidemia has traditionally been assessed using a fasting lipid profile [i.e. fasting triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C)]. However, the postprandial state predominates over the course of a day and non-fasting triglycerides independently predict CVD risk. In insulin resistant states, the intestine overproduces triglyceride-rich lipoprotein (TRL) particles, termed chylomicrons (CMs), following ingestion of a fat-containing meal, as well as in the fasting state. Along with elevated hepatic TRLs (i.e. very-low density lipoproteins), CMs contribute to remnant lipoprotein accumulation, small dense LDL particles, and reduced HDL-C, which collectively increase CVD risk. Given the early genesis of atherosclerosis and physiological metabolic changes during adolescence, studying postprandial dyslipidemia in the adolescent population is an important area of study. Postprandial dyslipidemia in the pediatric population poses a significant public health concern, warranting a better understanding of its pathogenesis and association with insulin resistance and CVD. This review discusses the metabolic syndrome, focusing on the link between insulin resistance, postprandial dyslipidemia, and CVD risk. Furthermore, the clinical significance and functional assessment of postprandial dyslipidemia, specifically in the adolescent population, is discussed in more detail.

Lipoprotein particles in patients with pediatric Cushing disease and possible cardiovascular risks

BACKGROUND

Cardiovascular (CV) complications are the most significant cause of mortality in adults with Cushing disease (CD); little is known about CV risk factors in children with CD. Measurement of lipoprotein particles by nuclear magnetic resonance (NMR) spectroscopy is a novel technology to assess CV risk. The objective of the current study is to analyze the NMR lipid profile in pediatric CD patients before and 1 year after remission.

METHODS

NMR lipid profile was obtained via the Vantera NMR analyzer, using frozen serum samples from 33 CD patients (mean age 13.8 ± 4.0 years) evaluated between 1997 and 2017 at the National Institutes of Health (NIH) Clinical Center (CC).

RESULTS

GlycA (glycosylated acute-phase proteins), triglyceride-rich particles (TRLP medium and very small sizes), low-density lipoprotein (LDL) particles (LDLP total and large size), high-density lipoprotein (HDL) particles (HDLP total, medium and small sizes), total cholesterol, LDL-cholesterol, HDL-cholesterol, GlycA inflammatory biomarker, and apolipoprotein B and apolipoprotein A1 (ApoA1) concentrations showed statistically significant changes after remission of CD (p < 0.05).

CONCLUSION

In our study population, most of the lipid variables improved post-CD remission, with the exception of HDL and ApoA1, indicating that NMR lipoprotein profile may be a helpful tool in assessing the CV risk in pediatric patients with CD.

Natural History of Atherosclerosis and Abdominal Aortic Intima-Media Thickness: Rationale, Evidence, and Best Practice for Detection of Atherosclerosis in the Young

Atherosclerosis underlies most myocardial infarctions and ischemic strokes. The timing of onset and the rate of progression of atherosclerosis differ between individuals and among arterial sites. Physical manifestations of atherosclerosis may begin in early life, particularly in the abdominal aorta. Measurement of the abdominal aortic intima-media thickness by external ultrasound is a non-invasive methodology for quantifying the extent and severity of early atherosclerosis in children, adolescents, and young adults. This review provides an evidence-based rationale for the assessment of abdominal aortic intima-media thickness-particularly as an age-appropriate methodology for studying the natural history of atherosclerosis in the young in comparison to other methodologies-establishes best practice methods for assessing abdominal aortic intima-media thickness, and identifies key gaps in the literature, including those that will identify the clinical relevance of this measure.

Quantitative Lipoprotein Subclass and Low Molecular Weight Metabolite Analysis in Human Serum and Plasma by 1H NMR Spectroscopy in a Multilaboratory Trial

We report an extensive 600 MHz NMR trial of quantitative lipoprotein and small-molecule measurements in human blood serum and plasma. Five centers with eleven 600 MHz NMR spectrometers were used to analyze 98 samples including 20 quality controls (QCs), 37 commercially sourced, paired serum and plasma samples, and two National Institute of Science and Technology (NIST) reference material 1951c replicates. Samples were analyzed using rigorous protocols for sample preparation and experimental acquisition. A commercial lipoprotein subclass analysis was used to quantify 105 lipoprotein subclasses and 24 low molecular weight metabolites from the NMR spectra. For all spectrometers, the instrument specific variance in measuring internal QCs was lower than the percentage described by the National Cholesterol Education Program (NCEP) criteria for lipid testing [triglycerides <2.7%; cholesterol <2.8%; low-density lipoprotein (LDL) cholesterol <2.8%; high-density lipoprotein (HDL) cholesterol <2.3%], showing exceptional reproducibility for direct quantitation of lipoproteins in both matrixes. The average relative standard deviations (RSDs) for the 105 lipoprotein parameters in the 11 instruments were 4.6% and 3.9% for the two NIST samples, whereas they were 38% and 40% for the 37 commercially sourced plasmas and sera, respectively, showing negligible analytical compared to biological variation. The coefficient of variance (CV) obtained for the quantification of the small molecules across the 11 spectrometers was below 15% for 20 out of the 24 metabolites analyzed. This study provides further evidence of the suitability of NMR for high-throughput lipoprotein subcomponent analysis and small-molecule quantitation with the exceptional required reproducibility for clinical and other regulatory settings.

Lipids and Lipoproteins in Risk Prediction

Ischemic heart disease remains the leading cause of death worldwide. Low-density lipoprotein cholesterol (LDL-C) has proved to have a causal relationship with atherosclerotic cardiovascular disease. Lowering LDL-C improves outcomes, although some patients continue to have residual risk of cardiovascular disease. Cardiovascular risk prediction calculators are routinely used in to identify patients most at risk. Research into other lipoprotein factors has suggested that they may have advantages over LDL-C and improve the ability to identify those most at risk. Although some technology is not widely available, there is potential for better risk prediction in specific groups.