Follow-up of children diagnosed with familial hypercholesterolemia in a national genetic screening program

Nailfold capillaroscopy reveals early peripheral microcirculation abnormalities in children affected by heterozygous familial hypercholesterolemia

BACKGROUND

nailfold capillaroscopy (NCF) is a non-invasive imaging technique to seek peripheral microcirculation abnormalities in children and adults. Familial hypercholesterolemia is a genetic disorder caused by mutations capable of increasing blood levels of low-density lipoproteins cholesterol (LDL-C), thus triggering early atherosclerosis. The study aims at evaluating peripheral microcirculation in children with heterozygous familial hypercholesterolemia (HeFH) by means of NFC in comparison with healthy peers and at searching for possible correlations between these abnormalities and patients' lipid panel.

METHODS

thirty-six HeFH patients were enrolled (13 males and 23 females. Mean age 8 ± 3 years; age range 3-13 years). They had increased levels of total cholesterol (237.9 ± 34.2 mg/dl) and LDL-C (154.2 ± 37.6 mg/dl). Both values were ≥95th gender and age specific centile. All the subjects in the study underwent NFC.

RESULTS

In 69.4 % of HeFH children nailfold capillaries were tortuous (p < 0.00001 compared to healthy controls). In 41.6 % the number of capillaries was markedly reduced (<7 capillaries/mm). The mean number of capillaries was 8.4 ± 2.6/mm in HeFH and 12.2 ± 1.4/mm in healthy controls (p < 0.00001). In 100 % of the sample size capillary blood flow was slowed down (p < 0.00001). In 50 % of the sample size a blood "sludge" phenomenon was seen (p < 0.00001). No gender differences were detected. Sludge phenomenon was seen only in those with LDL-C over 99th centile (p < 0.00001).

CONCLUSION

NCF allows the identification of an early peripheral microvascular dysfunction in HeFH children which is similar to that already seen in atherosclerotic disease. Prompt identification of these capillary abnormalities may be crucial in implementing early prevention measures.

Should We Be Screening for Ischaemic Heart Disease Earlier in Childhood?

Ischaemic heart disease is the most common cause of death in males and the second in the female gender. Yet we often only focus on identification and treatment of this foremost cause of death in adulthood. The review asks the question what form of coronary disease do we encounter in childhood, what predisposing factors give rise to atherosclerosis and what strategies in childhood could we employ to detect and reduce atherosclerosis development in later life.

Patient Perspectives Regarding Genetic Testing for Familial Hypercholesterolemia

Background

Familial hypercholesterolemia (FH) is a common genetic disorder resulting in high levels of low-density lipoprotein cholesterol and increased risk of atherosclerotic cardiovascular disease. Genetic testing for FH is recommended but is not available in most of Canada. Consequently, there is a paucity of data regarding patient experiences with genetic testing. The objectives of this study were to investigate the attitudes and perspectives of patients with FH who underwent genetic testing.

Methods

We administered an anonymous online survey to participants in the British Columbia Familial Hypercholesterolemia Registry who had undergone research-based genetic testing for FH. The survey included 25 questions and explored patients’ experiences with the genetic testing process, willingness to recommend genetic screening, and motivation to lower cholesterol levels.

Results

Among 183 respondents, 38 (20.7%) had a positive genetic test result, 27 (14.8%) had a negative result, and 118 (64.4%) were awaiting their results. Compared with individuals awaiting their test results, participants with a positive genetic test were more likely to believe lipid-lowering therapy was highly important (74.3% vs 55.4%; P = 0.05). They were also more likely to strongly agree that a diagnosis of FH was important to them (71.1% vs 46.2%; P = 0.008), and were more likely to recommend genetic screening to their family members (85.9% vs 72.9%; P = 0.04).

Conclusions

To our knowledge, this is the first study in Canada to explore the perspectives of patients with FH who underwent genetic testing. These results suggest that genetic testing for FH might offer benefits in important patient-centred outcomes.

Reducing cardiovascular disease risk among families with familial hypercholesterolaemia by improving diet and physical activity: a randomised controlled feasibility trial

OBJECTIVE

Familial hypercholesterolaemia (FH) elevates low-density lipoprotein cholesterol (LDL-C) and increases cardiovascular disease (CVD) risk. This study aimed to provide evidence for the feasibility of conducting a randomised controlled trial to evaluate the efficacy of an intervention designed to improve diet and physical activity in families with FH.

DESIGN

A parallel, randomised, waitlist-controlled, feasibility pilot trial.

SETTING

Three outpatient lipid clinics in the UK.

PARTICIPANTS

Families that comprised children (aged 10-18 years) and their parent with genetically diagnosed FH.

INTERVENTION

Families were randomised to either 12-week usual care or intervention. The behavioural change intervention aimed to improve dietary, physical activity and sedentary behaviours. It was delivered to families by dietitians initially via a single face-to-face session and then by four telephone or email follow-up sessions.

OUTCOME MEASURES

Feasibility was assessed via measures related to recruitment, retention and intervention fidelity. Postintervention qualitative interviews were conducted to explore intervention acceptability. Behavioural (dietary intake, physical activity and sedentary time) and clinical (blood pressure, body composition and blood lipids) outcomes were collected at baseline and endpoint assessments to evaluate the intervention's potential benefit.

RESULTS

Twenty-one families (38% of those approached) were recruited which comprised 22 children and 17 adults with FH, and 97% of families completed the study. The intervention was implemented with high fidelity and the qualitative data revealed it was well accepted. Between-group differences at the endpoint assessment were indicative of the intervention's potential for improving diet in children and adults. Evidence for potential benefits on physical activity and sedentary behaviours was less apparent. However, the intervention was associated with improvements in several CVD risk factors including LDL-C, with a within-group mean decrease of 8% (children) and 10% (adults).

CONCLUSIONS

The study's recruitment, retention, acceptability and potential efficacy support the development of a definitive trial, subject to identified refinements.

TRIAL REGISTRATION NUMBER

ISRCTN24880714.

The development of a theory informed behaviour change intervention to improve adherence to dietary and physical activity treatment guidelines in individuals with familial hypercholesterolaemia (FH)

BACKGROUND

Familial hypercholesterolaemia (FH) is a genetic condition characterised by elevated levels of low-density lipoprotein cholesterol (LDL-C) and an increased risk of cardiovascular disease (CVD). Following dietary and physical activity guidelines could help minimise this risk but adherence is low. Interventions to target these behaviours are therefore required. A comprehensive understanding of the target behaviours and behaviour change theory should drive the process of intervention development to increase intervention effectiveness and scalability. This paper describes the application of a theoretical framework to the findings of a qualitative evidence synthesis (QES) to inform the content and delivery of an intervention to improve adherence to dietary and physical activity guidelines in individuals with FH.

METHODS

The Behaviour Change Wheel (BCW) was used to guide intervention development. Factors influencing dietary and physical activity behaviours were identified from an earlier QES and mapped onto factors within the BCW. A comprehensive behavioural diagnosis of these factors was conducted through application of the theoretical domains framework (TDF). Using these data, the most appropriate intervention functions and behaviour change techniques (BCTs) for inclusion in the intervention were identified. Decision making was guided by evaluation criteria recommended by BCW guidance and feedback from individuals with FH.

RESULTS

Factors influencing dietary and physical activity behaviours mapped onto twelve of the fourteen TDF domains, with seven intervention functions deemed suitable to target the domains' theoretical constructs. Twenty-six BCTs were identified as being appropriate for delivery within these functions and were included in the intervention. For instance, within the enablement intervention function, the BCT problem solving was incorporated by inclusion of a 'barriers and solutions' section. Guided by evaluation criteria and feedback from individuals with FH, the intervention will be delivered as an hour-long family-based appointment, followed up with four telephone calls.

CONCLUSIONS

The novel application of the BCW and TDF to the results of a QES has enabled the development of a theory and evidence informed behaviour change intervention. This systematic approach facilitates evaluation of the intervention as part of an ongoing feasibility trial. The transparent approach taken can be used to guide intervention development by researchers in other fields.

Enablers and barriers to treatment adherence in heterozygous familial hypercholesterolaemia: a qualitative evidence synthesis

OBJECTIVES

Individuals with heterozygous familial hypercholesterolaemia (FH) are at high risk of developing cardiovascular disease (CVD). This risk can be substantially reduced with lifelong pharmacological and lifestyle treatment; however, research suggests adherence is poor. We synthesised the qualitative research to identify enablers and barriers to treatment adherence.

DESIGN

This study conducted a thematic synthesis of qualitative studies.

DATA SOURCES

MEDLINE, Embase, PsycINFO via OVID, Cochrane library and CINAHL databases and grey literature sources were searched through September 2018.

ELIGIBILITY CRITERIA

We included studies conducted in individuals with FH, and their family members, which reported primary qualitative data regarding their experiences of and beliefs about their condition and its treatment.

DATA EXTRACTION AND SYNTHESIS

Quality assessment was undertaken using the Critical Appraisal Skills Programme for qualitative studies. A thematic synthesis was conducted to uncover descriptive and generate analytical themes. These findings were then used to identify enablers and barriers to treatment adherence for application in clinical practice.

RESULTS

24 papers reporting the findings of 15 population samples (264 individuals with FH and 13 of their family members) across 8 countries were included. Data captured within 20 descriptive themes were considered in relation to treatment adherence and 6 analytical themes were generated: risk assessment; perceived personal control of health; disease identity; family influence; informed decision-making; and incorporating treatment into daily life. These findings were used to identify seven enablers (eg, 'commencement of treatment from a young age') and six barriers (eg, 'incorrect and/or inadequate knowledge of treatment advice') to treatment adherence. There were insufficient data to explore if the findings differed between adults and children.

CONCLUSIONS

The findings reveal several enablers and barriers to treatment adherence in individuals with FH. These could be used in clinical practice to facilitate optimal adherence to lifelong treatment thereby minimising the risk of CVD in this vulnerable population.

PROSPERO REGISTRATION NUMBER

CRD42018085946.

Genetic testing for familial hypercholesterolemia: Impact on diagnosis, treatment and cardiovascular risk

Aims

Familial hypercholesterolemia (FH) is the most common genetic disorder in medicine, with a prevalence of 1/250. Affected individuals have elevated low-density lipoprotein cholesterol (LDL-C) and an increased lifetime risk of atherosclerotic cardiovascular disease (ASCVD). The diagnosis of FH is based on algorithms that include LDL-C levels, physical manifestations, family history of high LDL-C and premature ASCVD, and, more recently, genetic testing. We sought to determine the impact of genetic testing on the: 1) diagnosis of ‘definite familial hypercholesterolemia’, 2) initiation and adherence of lipid-lowering therapy and 3) risk of ASCVD.

Methods

We performed a systematic review and meta-analysis, pooling odds ratios and 95% confidence intervals for ASCVD from studies comparing risk estimates in individuals harboring FH-causing variants and unaffected individuals.

Results

After screening 3304 unique publications, 56 studies were included in the analysis. 1) Genetic testing provided confirmation of FH in 28–80%, over clinical criteria alone, depending on the diagnostic algorithm and the method of analysis. In two large population-based studies comprising 76,751 individuals, an FH-causing variant was identified in only 1.7–2.5% of subjects with an LDL-C > 4.9 mmol/L (190 mg/dL). 2) A confirmed molecular diagnosis increased lipid-lowering therapy adherence (five studies, n = 4181 definite FH). 3) Loss-of-function variant of the LDLR were at a markedly increased risk of myocardial infarction (odds ratio 6.77, 95% confidence interval 4.75–9.66), and patients with a milder (hypomorphic) pathogenic LDLR change had a 4.4-fold increase in risk (odds ratio 4.4, 95% confidence interval 2.34–8.26), compared with controls.

Conclusion

DNA sequencing confirms the diagnosis of FH but has a poor yield in unselected patients whose sole criterion is an elevated LDL-C. Initiation and adherence to treatment is improved. The risk of ASCVD is 4.4- to 6.8-fold increased in patients with an FH-causing variant compared with controls, depending on the severity of the DNA change.

How do the experiences and beliefs of adults and children with heterozygous familial hypercholesterolaemia influence their adherence to treatment? A systematic review of qualitative evidence protocol

BACKGROUND

Heterozygous familial hypercholesterolaemia (FH) is a genetic disorder characterised by elevated levels of low density lipoprotein (LDL) cholesterol from birth, estimated to affect 1 in 250 of the UK population. Left untreated, FH substantially increases an individual's risk of premature coronary heart disease (CHD) and associated mortality. This risk can be minimised with timely diagnosis and successful treatment with medication and lifestyle changes, as advocated in national and international guidelines. Despite these recommendations, the limited research available suggests adherence to treatment may be sub-optimal. This review will identify and synthesise the available qualitative research regarding the experiences and beliefs of adults and children with FH in relation to their condition and its treatment, and the influence of these upon treatment adherence.

METHODS

The following electronic databases will be searched from their inception: Cochrane library, MEDLINE, Embase, PsycINFO (via OVID) and CINAHL. Studies available in English and reporting primary qualitative data will be included. Database searching will be supplemented with searches in relevant specialist websites. The references of identified papers will also be hand searched. Two reviewers will independently screen titles and abstracts of identified studies, with full texts of potentially relevant papers retrieved for review against pre-defined inclusion and exclusion criteria. The Critical Appraisal Skills Programme (CASP) Qualitative Research checklist will be used to assess quality of the included studies, and the results will be taken into consideration when reporting the findings. A data extraction tool will be created for use in this review to extract study findings relevant to the review questions. A thematic synthesis approach will be taken to analyse the results.

DISCUSSION

Adherence to treatment recommendations is crucial for the successful management of FH and subsequent decrease in risk of CHD later in life. Common identified themes could provide an understanding of the beliefs and experiences which influence adherence to treatment recommendations and provide an insight into perceived barriers and facilitators. The findings are intended to be used in the development of future interventions or guidelines regarding treatment of children and adults with FH.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42018085946.

Analysis of Children and Adolescents with Familial Hypercholesterolemia

OBJECTIVE

To evaluate the effectiveness of criteria based on child-parent assessment in predicting familial hypercholesterolemia (FH)-causative mutations in unselected children with hypercholesterolemia.

STUDY DESIGN

LDLR, APOB, and PCSK9 genes were sequenced in 78 children and adolescents (mean age 8.4 ± 3.7 years) with clinically diagnosed FH. The presence of polygenic hypercholesterolemia was further evaluated by genotyping 6 low-density lipoprotein cholesterol (LDL-C)-raising single-nucleotide polymorphisms.

RESULTS

Thirty-nine children (50.0%) were found to carry LDLR mutant alleles but none with APOB or PCSK9 mutant alleles. Overall, 27 different LDLR mutations were identified, and 2 were novel. Children carrying mutations showed higher LDL-C (215.2 ± 52.7 mg/dL vs 181.0 ± 44.6 mg/dL, P <.001) and apolipoprotein B levels (131.6 ± 38.3 mg/dL vs 100.3 ± 30.0 mg/dL, P <.004), compared with noncarriers. A LDL-C of ~190 mg/dL was the optimal value to discriminate children with and without LDLR mutations. When different diagnostic criteria were compared, those proposed by the European Atherosclerosis Society showed a reasonable balance between sensitivity and specificity in the identification of LDLR mutations. In children without mutation, the FH phenotype was not caused by the aggregation of LDL-C raising single-nucleotide polymorphisms.

CONCLUSIONS

In unselected children with hypercholesterolemia, LDL-C levels >190 mg/dL and a positive family history of hypercholesterolemia appeared to be the most reliable criteria for detecting FH. As 50% of children with suspected FH did not carry FH-causing mutations, genetic testing should be considered.

Attainment of LDL Cholesterol Treatment Goals in Children and Adolescents With Familial Hypercholesterolemia. The SAFEHEART Follow-up Registry

INTRODUCTION AND OBJECTIVES

Little is known about the characteristics of persons with familial hypercholesterolemia (FH) younger than 18 years, the lipid-lowering therapy used in these patients, and the lipid goals reached in real life. Our aim was to evaluate the achievement of low-density lipoprotein cholesterol (LDL-C) treatment goals in FH patients younger than 18 years enrolled in a large national registry.

METHODS

We analyzed patients younger than 18 years enrolled in a large ongoing registry of molecularly-defined patients with FH in Spain. The attainment of guideline-recommended plasma LDL-C goals at entry and follow-up was analyzed in relation to the use of lipid-lowering therapy.

RESULTS

We enrolled 392 individuals younger than 18 years. Of these, 217 were molecularly-diagnosed FH patients and had a complete follow-up. The median follow-up time was 4.69 years (interquartile range, 2.48-6.38 years), 68.2% of FH patients were on statins, and 41.5% patients had LDL-C < 130mg/dL. Statin use was the only predictor of LDL-C goal attainment.

CONCLUSIONS

This study shows that a high proportion of FH patients younger than 18 years have high LDL-C levels and fail to achieve recommended LDL-C targets. Statin use was the only independent predictor of LDL-C goal achievement. No safety concerns were detected during follow-up. These results indicate that many FH patients are not adequately controlled and that there is still room for treatment improvement.

Patterns and predictors of medication adherence to lipid-lowering therapy in children aged 8 to 20 years

BACKGROUND

The American Academy of Pediatrics recommends lipid-lowering therapy (LLT) for children at high risk of cardiovascular disease. However, the use of LLT in children is rare, and rates of nonadherence are unknown.

OBJECTIVE

To identify patterns of use and predictors of nonadherence to LLT in children aged 8 to 20 years and the subgroup with dyslipidemia.

METHODS

Commercially insured patients with a new dispensing for an LLT were included. Nonadherence was defined as a gap of >90 days between the last dispensing plus the medication days supply and the next dispensing or censoring. Descriptive statistics characterize the patterns of LLT adherence and class-specific drug switching. Kaplan-Meier curves and multivariable Cox proportional hazard models identified time to, and predictors of, nonadherence for the cohort and the dyslipidemia subgroup.

RESULTS

Of the 8710 patients meeting inclusion criteria, 87% were nonadherent. Statins were the most common index prescription, and patients with an index statin dispensing were more likely to have multiple comorbidities and other prescription drug use. In multivariable analyses, nonadherence was inversely associated with dyslipidemia (hazard ratio [HR] = 0.61, 95% confidence interval [CI] = 0.57-0.65), chronic kidney disease (HR = 0.69, 95% CI = 0.54-0.88), higher outpatient (HR = 0.87, 95% CI = 0.77-0.98), and inpatient (HR = 0.83, 95% CI = 0.70-0.97) use. When limited to patients with dyslipidemia, nonadherence was related to age (HR = 1.21, 95% CI = 1.07-1.38) and obesity (HR = 1.23, 95% CI = 1.02-1.49).

CONCLUSIONS

Despite recommendations to begin continuous treatment early for high-risk children, nonadherence to LLT is frequent in this population, with modestly higher adherence in children with dyslipidemia.

Expert and Advocacy Group Consensus Findings on the Horizon of Public Health Genetic Testing

Description: Among the two leading causes of death in the United States, each responsible for one in every four deaths, heart disease costs Americans $300 billion, while cancer costs Americans $216 billion per year. They also rank among the top three causes of death in Europe and Asia. In 2012 the University of Michigan Center for Public Health and Community Genomics and Genetic Alliance, with the support of the Centers for Disease Control and Prevention Office of Public Health Genomics, hosted a conference in Atlanta, Georgia to consider related action strategies based on public health genomics. The aim of the conference was consensus building on recommendations to implement genetic screening for three major heritable contributors to these mortality and cost figures: hereditary breast and ovarian cancer (HBOC), familial hypercholesterolemia (FH), and Lynch syndrome (LS). Genetic applications for these three conditions are labeled with a “Tier 1” designation by the U.S. Centers for Disease Control and Prevention because they have been fully validated and clinical practice guidelines based on systematic review support them. Methodology: The conference followed a deliberative sequence starting with nationally recognized clinical and public health presenters for each condition, followed by a Patient and Community Perspectives Panel, working group sessions for each of the conditions, and a final plenary session. The 74 conference participants represented disease research and advocacy, public health, medicine and nursing, genetics, governmental health agencies, and industry. Participants drew on a public health framework interconnecting policy, clinical intervention, surveillance, and educational functions for their deliberations. Results: Participants emphasized the importance of collaboration between clinical, public health, and advocacy groups in implementing Tier 1 genetic screening. Advocacy groups could help with individual and institutional buy-in of Tier 1 programs. Groups differed on funding strategies, with alternative options such as large-scale federal funding and smaller scale, incremental funding solutions proposed. Piggybacking on existing federal breast and colorectal cancer control programs was suggested. Public health departments need to assess what information is now being collected by their state cancer registries. The groups advised that information on cascade screening of relatives be included in toolkits for use by states. Participants stressed incorporation of family history into health department breast cancer screening programs, and clinical HBOC data into state surveillance systems. The carrying out of universal LS screening of tumors in those with colorectal cancer was reviewed. Expansion of universal screening to include endometrial tumors was discussed, as was the application of guidelines recommending cholesterol screening of children 9–11 years old. States more advanced in terms of Tier 1 testing could serve as models and partners with other states launching screening and surveillance programs. A multidisciplinary team of screening program champions was suggested as a means of raising awareness among the consumer and health care communities. Participants offered multiple recommendations regarding use of electronic health records, including flagging of at-risk family members and utilization of state-level health information exchanges. The paper contains an update of policy developments and happenings for all three Tier 1 conditions, as well as identified gaps. Conclusions: Implementation of cascade screening of family members for HBOC and FH, and universal screening for LS in CRC tumors has reached a point of readiness within the U.S., with creative solutions at hand. Facilitating factors such as screening coverage through the Patient Protection and Affordable Care Act, and state health information exchanges can be tapped. Collaboration is needed between public health departments, health care systems, disease advocacy groups, and industry to fully realize Tier 1 genetic screening. State health department and disease networks currently engaged in Tier 1 screening can serve as models for the launch of new initiatives.

Importance of early recognition of heterozygous familial hypercholesterolaemia

PURPOSE OF REVIEW

To outline recent updates in the diagnosis and management of heterozygous familial hypercholesterolaemia.

RECENT FINDINGS

Recent guidelines have suggested that familial hypercholesterolaemia is vastly underdiagnosed in most countries worldwide. Improvements in next-generation sequencing have led to the detection of novel mutations and the cheaper cost of this technology makes the early identification of asymptomatic individuals a feasible option. With more widespread use of high doses of more potent statins in affected adults, cardiovascular mortality has decreased in adults with hypercholesterolaemia.

SUMMARY

Barriers to cascade testing of relatives of index cases remain worldwide despite improvements in gene technology and the marked recent decrease in costs of genetic testing. Recent guidelines recommending screening of young children, for example, 8-10 years with measurement of LDL cholesterol concentrations will increase the diagnosis of familial hypercholesterolaemia among children but long-term safety data of the use of statins in this young age group are not available. To date, the benefit of statin-induced decreases in LDL cholesterol concentration in children is based on effects of treatment on proxy measures of cardiovascular disease and not a reduction in cardiovascular events.

Cascade Screening in Familial Hypercholesterolemia: Advancing Forward

Familial hypercholesterolemia is a genetic disorder associated with elevated LDL-cholesterol and high lifetime cardiovascular risk. Both clinical and molecular cascade screening programs have been implemented to increase early definition and treatment. In this systematic review, we discuss the main issues found in 65 different articles related to cascade screening and familial hypercholesterolemia, covering a range of topics including different types/strategies, considerations both positive and negative regarding cascade screening in general and associated with the different strategies, cost and coverage consideration, direct and indirect contact with patients, public policy around life insurance and doctor-patient confidentiality, the "right to know," and public health concerns regarding familial hypercholesterolemia.

Patterns of Lipid Lowering Therapy among Children Ages 8-20 Years

OBJECTIVES

Pediatric guidelines in 2008 and 2011 recommended lipid lowering therapy in children ≥ 8 years of age with high-risk cardiovascular conditions, such as familial hypercholesterolemia (FH). Our objective was to describe the patterns and predictors of lipid lowering therapy initiation in commercially insured children between 2005 and 2010.

STUDY DESIGN

Using commercial health plan data on children ages 8-20 years from 2004-2010, we estimated rates of lipid lowering therapy initiation overall and stratified by age. Using a nested case-control design, we used multivariable logistic regression to identify temporal, demographic, clinical, and health utilization characteristics associated with lipid lowering therapy initiation.

RESULTS

Among >13 million children, 665 initiated lipid lowering therapy for an incidence rate 2.6/100,000 person-years (PY). Incidence rates were highest in 2005 (4.1/100,000 PY) and 2008 (3.9/100,000 PY), with no discernable secular trend. Rates of lipid lowering therapy initiation were significantly greater in children ≥ 15 years of age (OR 2.9 [95% CI 5.2-13.0]), males (2.1 [1.7-2.4]), and those with a diagnosis of FH (165.2 [129.0-211.6]), other dyslipidemia (175.5 [143.2-215.3]), diabetes type I (7.7 [4.7-12.4]), diabetes type II (13.6 [8.5-21.7]), hypertension (8.1 [4.9-13.3]), obesity (7.8 [4.7-12.7]), and ≥ 5 outpatient visits (1.5 [1.2-1.7]), and children with dispensing of ≥ 2 nonlipid lowering therapy prescriptions were less likely to initiate lipid lowering therapy (0.2 [0.2-0.3]).

CONCLUSIONS

Despite new guidelines, lipid lowering therapy initiation in children is low and has not increased through 2010. Although diagnosis of FH and other dyslipidemias was associated with higher probability of lipid lowering therapy initiation, our findings suggest lipid lowering therapy is underutilized in this population given the prevalence of these disorders.

Update on screening, etiology, and treatment of dyslipidemia in children

CONTEXT

Cardiovascular disease is a leading cause of morbidity and mortality. Early identification and treatment of risk factors that accelerate this condition are paramount to preventing disease. To this effect, the National Heart Lung and Blood Institute (NHLBI), endorsed by the American Academy of Pediatrics, issued updated pediatric guidelines for cardiovascular risk reduction in 2011. Integration of these guidelines into pediatric practice may lessen cardiovascular morbidity.

EVIDENCE ACQUISITION

In addition to reviewing the NHLBI guidelines, a detailed literature search was performed on PubMed for clinical studies published between 2010 and 2013. Key search terms included "pediatric dyslipidemia/hyperlipidemia," "cardiovascular disease," "atherosclerosis," "familial hypercholesterolemia," "hypertriglyceridemia," and "diabetes." Additional citations from these publications were also reviewed. Final publications were selected for their relevance to the topic.

EVIDENCE SYNTHESIS

These guidelines contain several important recommendations relative to lipid management, including screening all children with nonfasting non-high-density lipoprotein-cholesterol at ages 9-11 years, incorporation of aggressive lifestyle changes to meet cholesterol targets, and initiation of statin therapy for those with low-density lipoprotein-cholesterol elevation. In addition, both type 1 and type 2 diabetes are now considered high-risk conditions and have stringent cholesterol targets. The primary aim is early identification of children with familial hypercholesterolemia; however, these recommendations have met with some controversy. The purpose of this update is to summarize these recent lipid guidelines, present the relevant controversies, highlight common cholesterol disorders, and discuss dyslipidemia specific to the pediatric diabetes population.

CONCLUSION

Identification and treatment of youth with dyslipidemia is of paramount importance to the reduction of future cardiovascular disease. Increasing the comprehension and application of the newest NHLBI guidelines is critical to improving cardiovascular outcomes.

Management of hypercholesterolemia in children

Cardiovascular disease (CVD) remains the leading cause of death and morbidity in our society. One of the major risk factors for CVD is hypercholesterolemia. Hypercholesterolemia in children can be caused by a hereditary disorder or can be secondary to other diseases or drugs. In order to prevent CVD later in life, children with hypercholesterolemia should be identified and treated as early as possible. Currently, several different screening strategies have been developed, using either universal screening or case finding to search for children at risk. Once those children are identified, the first step in treatment is lifestyle adjustment. If cholesterol levels remain elevated, the drugs of first choice are statins. Other pharmacological options are ezetimibe or bile acid sequestrants. These agents have all proven to be safe and effective in lowering low-density lipoprotein cholesterol levels and improving surrogate markers of CVD. However, there is a need for long-term follow-up studies to answer the question as to whether it is safe to initiate treatment at a young age to prevent CVD later in life.

Familial hypercholesterolemia affects microvascular autoregulation in children

OBJECTIVE

Familial hypercholesterolemia (FH) impairs macrovascular endothelial function in childhood and causes an increase of cardiovascular risk in later life. Whether microvascular function is affected in children with FH is unknown. The aim of this study was to investigate the impact of FH on microvascular autoregulation in children by post occlusive reactive hyperemia (PORH).

METHODS

PORH of the skin was assessed using laser Doppler fluxmetry. Baseline perfusion, biological zero, defined as no-flow laser Doppler signal during suprasystolic occlusion, peak perfusion after release of suprasystolic occlusion, as well as time to peak perfusion and recovery time, defined as time until baseline perfusion is resumed, were measured in 16 children, who were diagnosed with FH according to current guidelines, and in 91 healthy controls.

RESULTS

In children with FH, peak perfusion was higher (FH: 1.60±0.68 vs. controls: 1.26±0.50 AU [arbitrary units], p=0.02), recovery time was longer (110±42.61 vs. 83.18±35.08 s, p=0.01) and biological zero was lower than in controls (0.12±0.04 vs. 0.18±0.05 AU, p<0.001). Baseline perfusion and time to peak were not different between children with FH and controls (baseline perfusion: 0.43±0.21 vs. 0.38±0.15 AU, p=0.18; time to peak: 15.44±12.25 vs. 18.18±17.79 s, p=0.56).

CONCLUSION

For the first time the present study reveals an impact of FH on microvascular autoregulation in children: the differences of PORH between children with FH and controls indicate an affected autoregulation of microvascular blood flow in FH, which has its onset in childhood.

Familial hypercholesterolemia in children and adolescents

PURPOSE OF REVIEW

This review provides an update and highlights the controversies regarding recent advances and recommendations regarding screening, diagnosis and treatment of children and adolescents with familial hypercholesterolemia.

RECENT FINDINGS

Both general cardiovascular risk and specific familial hypercholesterolemia guidelines for children and adolescents have recently been released. Universal lipid screening of children has been recommended, in addition to targeted screening. The role of genetic testing for targeted screening and diagnostic confirmation is less clear. Although lifestyle therapy remains of key importance, increasing evidence of safety and efficacy support the use of statin therapy. Early therapy has been associated with improvements in noninvasive measures of early atherosclerosis in children, which likely can be extrapolated to improved freedom from cardiovascular disease events over the lifespan, as has been observed in adults. The new guidelines provide general and specific recommendations as to how family history and additional risk factors and risk conditions should be incorporated in decisions regarding initiation of statin therapy at LDL-cholesterol cutpoints. Emerging evidence from observational studies are beginning to address concerns regarding the initiation at young ages and longer-term efficacy and safety.

SUMMARY

Children and adolescents with familial hypercholesterolemia can be identified and effective therapy with a statin initiated with consideration of the patients' overall cardiovascular risk profile, remaining mindful of the uncertainties regarding long-term safety.