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

Hypertension and Cardiovascular Risk Among Children with Chronic Kidney Disease

PURPOSE OF REVIEW

Cardiovascular disease is the most common cause of mortality across the lifespan of children with chronic kidney disease (CKD). Hypertension is a common and important contributor, but other factors such as obesity, dyslipidemia and mineral bone disease play a role. This narrative review focusses on studies published in the past five years that have investigated hypertension and cardiovascular risk among children with CKD.

RECENT FINDINGS

Cohort studies such as Chronic Kidney Disease in Children (CKiD) and Cardiovascular Comorbidity in Children with CKD (4C) have continued to develop our understanding of blood pressure (BP) phenotypes, and of progressive changes in the structure and function of the heart and blood vessels occurring in children with CKD. Metabolic risk factors, such as dyslipidemia, may represent an under-recognized component of care. Trial data are less common than observational evidence, but support lifestyle interventions currently used, mainly the low sodium dietary approaches to stop hypertension (DASH) diet. The findings of the recently reported Hypertension Optimal Treatment in Children with Chronic Kidney Disease trial (HOT-KID) are described in relation to the use of office BP treatment targets. Cardiovascular health is critical to the long-term outcomes of children with CKD. Recognizing and treating hypertension remains a critical component to improving outcomes, along with measures to improve concurrent cardiovascular risk factors. Some cardiovascular changes may not be reversible with transplantation and further research is needed for children at all stages of CKD.

Co-Development of Three Dietary Indices to Facilitate Dietary Intake Assessment of Pediatric Crohn's Disease Patients

Literature on dietary behaviours of the pediatric Crohn's Disease (CD) population and the relationship between dietary intake and CD activity is limited. Three dietary indices were developed and tested to conduct dietary pattern analysis in pediatric patients with CD consuming a free diet following remission induction via exclusive enteral nutrition (n = 11). Index scores underwent descriptive and inferential analysis. The mean adjusted scores (out of 100) for the Pediatric Western Diet Index, Pediatric Prudent Diet Index, and Pediatric-Adapted 2010 Alternate Healthy Eating Index (PA2010-AHEI) were 29.82 ± 15.22, 34.25 ± 15.18, and 51.50 ± 11.69, respectively. The mean Western-to-Prudent ratio was 0.94 ± 0.55. A significant correlation (r = -0.71) and relationship (F[1, 9] = 9.04, P < 0.05, R2 = 0.501) between the Western-to-Prudent ratio and PA2010-AHEI was found. The results suggest participants were not following a Western or Prudent diet, and were consuming foods not captured by the indices. More research is needed to describe dietary intake of individuals with CD, validate dietary indices in diverse samples, and explore the utility of these indices in CD assessment and treatment. The co-authors hope this work will stimulate/inspire subsequent interprofessional, dietitian-led research on this topic.

Is Family History for the Management of Cardiovascular Health in Youth Still Relevant in Clinical Practice?

PURPOSE OF REVIEW

Family history of premature cardiovascular disease is a strong predictor of individual cardiovascular risk. However, family history is not always available and not always reliable. Roughly 80% of health outcomes are influenced not by genetic risk but by societal factors, including adverse health behaviors and environment. Furthermore, in the present age of genetic testing, laboratory evaluations, and imaging, a key question remains: What is the contemporary relevance of family history screening in the management of cardiovascular disease in youth?

RECENT FINDINGS

Knowledge of an individual's family history can help clinicians identify not only inherited risk but also familial clustering of unhealthy behaviors and environmental adversity contributing to enhanced cardiovascular disease risk in youth. For those at greatest risk, prevention strategies can be applied sooner and more conservatively. Integrating family history into clinical practice is crucial for cardiovascular risk assessment and for optimizing outcomes, but, in some cases, is more reflective of social factors.

Canadian Society of Clinical Chemists Harmonized Pediatric Lipid Reporting Recommendations for Clinical Laboratories

Detecting dyslipidemia early is important because atherosclerosis originates in childhood and early treatment can improve outcomes. In 2022, the Canadian Cardiovascular Society (CCS) and Canadian Pediatric Cardiology Association (CPCA) published a clinical practice update to detect, evaluate, and manage pediatric dyslipidemia. However, guidance on its translation into clinical laboratories is lacking. The Canadian Society of Clinical Chemists Working Group on Reference Interval Harmonization Lipid Team aims to assist guideline implementation and promote harmonized pediatric lipid reporting across Canada. The 2022 CCS/CPCA clinical practice update, 2011 National Heart, Lung, and Blood Institute integrated guidelines, and new data analysis (Canadian pediatric reference values from the Canadian Laboratory Initiative on Pediatric Reference Intervals [CALIPER] and retrospective patient data from large community laboratories) were incorporated to develop 5 key recommendations. These include recommendations to: (1) offer nonfasting and fasting lipid testing; (2) offer a lipid panel including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, and triglycerides, with apolipoprotein B and lipoprotein(a) available as individually orderable tests; (3) flag total cholesterol, LDL-C, and non-HDL-C results ≥ 95th percentile, and HDL-C results < 10th percentile, as recommended by CCS/CPCA/National Heart, Lung, and Blood Institute and validated by CALIPER, and flag apolipoprotein B and nonfasting triglyceride results ≥ 95th percentile on the basis of CALIPER, and do not flag Lp(a) results but mention the adult cutoff in the interpretive comments; (4) implement interpretive comments listed in the current report; and (5) implement the National Institutes of Health LDL-C equation. The Canadian Society of Clinical Chemists Working Group on Reference Interval Harmonization Lipid Team will support clinical laboratories to implement these recommendations using knowledge translation strategies. Harmonizing pediatric lipid reporting across Canadian clinical laboratories will optimize clinical decision-making and improve cardiovascular risk management in youth.

Cholesterol Interference in the Assessment of Vitamin D Status: A Canadian Health Measures Survey Biobank Project

BACKGROUND

Matrix effects are a known problem with immunoassays measuring serum 25-hydroxyvitamin D [25(OH)D].

OBJECTIVES

To determine if the inverse association between serum 25(OH)D and serum cholesterol concentrations is a function of assay method: Diasorin Liaison 25(OH) Vitamin D Total Assay (Liaison Total Assay), an immunoassay, compared with liquid chromatography tandem mass spectrometry (LC-MS/MS).

METHODS

Canadian Health Measures Survey data and biobank serum (White males aged 20-79 y, n = 392) were evaluated for bias in serum 25(OH)D using Bland-Altman plots. Differences in serum 25(OH)D (Liaison Total Assay - LC-MS/MS) were compared among non-HDL-cholesterol <4.2 (n = 295) compared with ≥4.2 (n = 97) mmol/L and total cholesterol groups <5.2 (n = 256) compared with ≥5.2 (n = 136) mmol/L, and associations tested between 25(OH)D and non-HDL-cholesterol or total cholesterol concentrations, using regression.

RESULTS

Serum 25(OH)D measured using Liaison Total Assay ranged from 10.7 to 137.0 nmol/L and 14.4 to 137.9 nmol/L by LC-MS/MS. Liaison Total Assay - LC-MS/MS showed a negative bias of 5.5 (95% limits of agreement -23.8, 12.7) nmol/L. Differences in 25(OH)D were -4.0 ± 9.0 (±SD) nmol/L if non-HDL-cholesterol was <4.2 mmol/L and -10.2 ± 8.7 nmol/L if ≥4.2 mmol/L (P < 0.0001). Differences in 25(OH)D, if total cholesterol was <5.2 mmol/L, were -3.4 ± 8.6 nmol/L and -9.6 ± 9.3 nmol/L if ≥5.2 mmol/L (P < 0.0001). Serum non-HDL-cholesterol (beta -3.17, P = 0.0014) and total cholesterol (beta -2.77, P = 0.0046) were inversely associated with Liaison Total Assay 25(OH)D (adjusted for age, fasting, and body mass index), but not with LC-MS/MS measured 25(OH)D. Interference by these lipoproteins was not eliminated by standardization of the Liaison Total Assay. Similar associations were observed with triglycerides as for the lipoproteins.

CONCLUSIONS

Total cholesterol inversely associates with 25(OH)D, which is likely due to elevated non-HDL-cholesterol lipoprotein or triglyceride interference with the Liaison Total Assay. This is important as elevated cholesterol is common, and an underestimation of vitamin D status could be an unnecessary cause for concern.

Uncertain benefit of statins in pediatric heart transplant recipients: A PHTS analysis

BACKGROUND

Cardiac allograft vasculopathy (CAV) is a leading cause of graft failure in pediatric heart transplant recipients (HTRs). Early statin use has been shown to reduce CAV incidence and all-cause mortality in adult HTRs. We sought to evaluate the contemporary prevalence and trends of statin use in pediatric HTRs and the association between statin use with CAV development and graft failure.

METHODS

Patients aged <17 years at the time of primary heart transplant who survived to ≥3 years without CAV were identified from the Pediatric Heart Transplant Society database (2001-2018). Statin use in the first 3 years posttransplant was defined as consecutive, intermediate, or absent. Kaplan-Meier survival, multivariable modeling, and propensity score-matched analyses evaluated associations between statin use and CAV incidence and graft survival, with subanalyses performed on subjects aged ≥10 years at transplant.

RESULTS

Among 3,485 (of which 1,086 aged ≥10 years) HTRs, 584 (17%) received consecutive statin therapy, 647 (19%) received intermediate use, and 2,254 (65%) received no statin therapy. Statin use varied widely between sites, with increasing use in the ≥10-year-old cohort over time. By multivariate analysis, statin use was not associated with graft loss. Consecutive statin use was also not associated with graft survival or freedom from CAV development when compared to absent statin use in unmatched or propensity-matched analyses.

CONCLUSIONS

While statins remain commonly utilized in pediatric HTRs, early consecutive statin therapy did not decrease CAV incidence or graft loss. The differing effects of statins on CAV development and progression in pediatric vs adult HTRs suggest differing risk and mediating factors and require further study.

Establishing non-fasting reference values for plasma lipids levels based on age, sex, and puberty stage in a French-Canadian pediatric population

BACKGROUND

Dyslipidemias, including familial hypercholesterolemia (FH), are a significant risk factor for cardiovascular diseases. FH is a genetic disorder resulting in elevated levels of low-density lipoprotein cholesterol (LDL-C) and an increased probability of early cardiovascular disorders. Heterozygous familial hypercholesterolemia (HeFH) is the most common form, affecting approximately 1 in 250 individuals worldwide, with a higher prevalence among the French-Canadian population. Childhood is a critical period for screening risk factors, but the recommendation for non-fasting screening remains controversial due to a lack of specific reference values for this state. This study aims to establish reference values for lipid levels in non-fasting children from Sherbrooke, Quebec, Canada, that will be specific for sex, age, and pubertal stages.

METHODS

Blood samples and corresponding anthropometric data were collected from 356 healthy children aged from 6 to 13. They were categorized either into two age groups: Cohort 6-8 and Cohort 9-13, or into pubertal stages. Reference values, specifically the 2.5th, 5th, 10th, 50th, 90th, 95th, and 97.5th percentiles were determined using the CLSI C28-A3 guidelines.

RESULTS

Lipid profiles did not significantly differ between sexes, except for higher levels of high-density lipoprotein (HDL-C) in boys within Cohort 6-8. HDL-C levels significantly increased, while LDL-C and non-HDL-C levels significantly decreased in both sexes with age. Non-fasting age- and pubertal stages-specific reference values were established.

CONCLUSION

This study established reference intervals for lipid markers in non-fasting state within the pediatric French-Canadian population. These findings could be used in dyslipidemia screening in daily practice.

Prediction of atherosclerotic cardiovascular risk in early childhood

Atherosclerotic lesions are present even in very young individuals and therefore, risk stratification for cardiovascular (CV) disease should be implemented in childhood to promote early prevention strategies. In this review we critically appraise clinical, biochemical and genetic biomarkers available for pediatric clinical practice, which might be integrated to build effective algorithms to identify children at risk of future CV events. The first critical issue is to characterize in children aged 2-5 years, those CV risk factors/clinical conditions associated with dramatically accelerated atherosclerosis. Presence of clinical conditions such as obesity, diabetes mellitus, Kawasaki disease, etc., or positive family history for premature CV disease should be evaluated. Subsequently, a complete lipid profile and Lipoprotein(a) determination are recommended for children with increased baseline CV risk. Individuals with altered lipid profile could then undergo genetic testing for monogenic dyslipidemias to identify children with high CV genetic risk, who will be directed to appropriate therapeutic options. In perspective, calculation of a polygenic risk score, based on the analysis of several common single-nucleotide polymorphisms, could be integrated for better risk assessment. We here emphasize the importance of a "holistic" strategy integrating biochemical, anamnestic and genetic data to stratify CV risk in early childhood.

International Atherosclerosis Society guidance for implementing best practice in the care of familial hypercholesterolaemia

This contemporary, international, evidence-informed guidance aims to achieve the greatest good for the greatest number of people with familial hypercholesterolaemia (FH) across different countries. FH, a family of monogenic defects in the hepatic LDL clearance pathway, is a preventable cause of premature coronary artery disease and death. Worldwide, 35 million people have FH, but most remain undiagnosed or undertreated. Current FH care is guided by a useful and diverse group of evidence-based guidelines, with some primarily directed at cholesterol management and some that are country-specific. However, none of these guidelines provides a comprehensive overview of FH care that includes both the lifelong components of clinical practice and strategies for implementation. Therefore, a group of international experts systematically developed this guidance to compile clinical strategies from existing evidence-based guidelines for the detection (screening, diagnosis, genetic testing and counselling) and management (risk stratification, treatment of adults or children with heterozygous or homozygous FH, therapy during pregnancy and use of apheresis) of patients with FH, update evidence-informed clinical recommendations, and develop and integrate consensus-based implementation strategies at the patient, provider and health-care system levels, with the aim of maximizing the potential benefit for at-risk patients and their families worldwide.

Exploring Barriers and Facilitators to Indirect Cascade Screening for Familial Hypercholesteraemia in a Paediatric/Parent Population

Background

Familial hypercholesteraemia (FH), an inherited disorder of cholesterol metabolism, has a prevalence of 1:250 and an associated 6- to 22-fold increased risk for cardiovascular disease. Despite the prevalence and availability of effective risk-reduction treatments, 90% of at-risk Canadians are undiagnosed. Indirect cascade screening from an index case is useful but the uptake is low (<4%), suggesting that barriers may exist. Using the Theoretical Domains Framework, we sought to determine barriers and facilitators among parents of children diagnosed with FH that may influence the uptake of cascade screening among families.

Methods

A qualitative description approach was used for virtual interviews with 10 parents of children with FH, recruited from a regional Lipid Clinic in Toronto, Canada. Semistructured interviews were conducted. The data were analysed using a directed content analysis method.

Results

Five interconnecting themes were identified that captured both facilitators and barriers of indirect cascade screening: a high level of knowledge about FH after clinic attendance; parents' surprise of their child's diagnosis and ongoing worry; parents' willingness to communicate the need for cholesterol screening; parents' desire for educational materials, dictated by an external vs internal locus of control; and social and societal influences including the lack of awareness about FH in professional and public domains.

Conclusions

The themes identified will inform next steps in programme development. An urgent need was identified for strategies to educate the public and primary care providers about FH and blood cholesterol/genetic screening.

Factors Associated With the Development of Dyslipidemia Among Pediatric Patients With Diabetes: A Single-centre-based Study

OBJECTIVES

The prevalence of pediatric diabetes is increasing. Dyslipidemia is an important modifiable cardiovascular disease risk factor often present in children with diabetes. In this study, we evaluated the adherence to Diabetes Canada 2018 lipid screening guidelines in a pediatric diabetes program to determine the prevalence of dyslipidemia in youth with diabetes and to identify risk factors related to dyslipidemia.

METHODS

This retrospective chart review included patients at McMaster Children's Hospital with diabetes (types 1 and 2), who were at least 12 years of age as of January 1, 2019. Extracted data included age, sex, family history of diabetes or dyslipidemia, date of diagnosis, body mass index, glycemia monitoring system used, lipid profile, glycated hemoglobin (A1C), and thyroid-stimulating hormone values at the time the lipid profile was measured. Statistical methods included descriptive statistics and logistic regression modelling.

RESULTS

Of the 305 patients included, 61% had a lipid profile measured according to guidelines, 29% had lipid screening completed outside of the recommended window, and 10% had no lipid profile on record. Among screened patients, 45% had dyslipidemia, most commonly hypertriglyceridemia (35%). Dyslipidemia was highest amongst those with type 2 diabetes, obesity, older age, short duration of diabetes, higher A1C, and those who used capillary blood glucose for monitoring (p<0.05).

CONCLUSIONS

A high proportion of patients were screened for dyslipidemia, but many outside the recommended window. Dyslipidemia is highly prevalent in this patient population and was associated with the presence of obesity, but 44% of patients without obesity also had dyslipidemia.

Evaluating the prevalence of lipid assessments in children in Alberta, Canada

BACKGROUND

Familial hypercholesterolemia is a common, inherited, life-threatening and treatable condition that is characterized by marked elevations of low-density lipoprotein cholesterol (LDL-C), resulting in a high risk of cardiovascular disease, but treatment starting in childhood dramatically reduces this risk. We sought to evaluate the prevalence of pediatric lipid assessments among children in Alberta.

METHODS

We reviewed laboratory and administrative data from Alberta Health between Apr. 1, 2012, and Dec. 31, 2021. We evaluated 2 pediatric cohorts (children aged 2-10 yr and children aged 9-17 yr) to allow for longitudinal assessments throughout the pediatric period. We also reviewed annual frequencies of lipid assessment for all children between 2013 and 2021.

RESULTS

Pediatric lipid assessments were performed for 1972 (4.3%) of 46 170 children aged 2-10 years and for 8158 (19.9%) of 40 926 children aged 9-17 years. Female children (aged 2-10 yr) and those living in rural communities were significantly less likely to have a lipid assessment, compared with male children and those in nonrural communities. Among those with lipid assessments, 23 (1.2%) and 86 (1.1%) children aged 2-10 years and 9-17 years, respectively, had an LDL-C level suggestive of probable familial hypercholesterolemia (≥ 4.0 mmol/L). Statin therapy was prescribed in 16 children during the study period. The frequency of lipid assessments was relatively stable, with the exception of a decrease in 2020.

INTERPRETATION

Rates of pediatric lipid assessment in Alberta are suboptimal. These findings highlight the need to increase awareness of the benefits of early diagnosis and treatment of familial hypercholesterolemia with regard to long-term health and identify and overcome barriers to diagnosis and treatment.