Putting Into Perspective the Hazards of Untreated Familial Hypercholesterolemia

Cholesterol Screening in Children: Is a Universal Approach Working?

PURPOSE OF REVIEW

Ample evidence supports that an individual's lifetime risk of atherosclerotic cardiovascular disease correlates to long-term, cumulative exposure to circulating cholesterol levels, beginning in childhood. Selective screening strategies based on family history fail to identify many children with hypercholesterolemia. Universal cholesterol screening in childhood is a worthwhile goal. However, cholesterol screening rates through childhood remain low.

RECENT FINDINGS

Mounting evidence clarifies the barriers to cholesterol screening in children. Specific strategies to foster universal screening in childhood have been proposed.

SUMMARY

We present an overview of the present state of childhood cholesterol screening, summarizing historical and contemporary guidelines and collating evidence of low adherence to current guidelines. We contend that novel approaches to universal cholesterol screening in childhood are warranted, and we present potential opportunities for improvement. We call for new and universal pediatric cholesterol screening guidelines.

The Inherited Hypercholesterolemias

Inherited hypercholesterolemias include monogenic and polygenic disorders, which can be very rare (eg, cerebrotendinous xanthomatosis (CTX)) or relatively common (eg, familial combined hyperlipidemia [FCH]). In this review, we discuss familial hypercholesterolemia (FH), FH-mimics (eg, polygenic hypercholesterolemia [PH], FCH, sitosterolemia), and other inherited forms of hypercholesterolemia (eg, hyper-lipoprotein(a) levels [hyper-Lp(a)]). The prevalence, genetics, and management of inherited hypercholesterolemias are described and selected guidelines summarized.

Familial Hypercholesterolemia and Elevated Lipoprotein(a): Cascade Testing and Other Implications for Contextual Models of Care

Elevated lipoprotein(a) [Lp(a)], a predominantly genetic disorder, is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valvular disease, particularly in patients with familial hypercholesterolemia (FH), a Tier I genomic condition. The combination from birth of the cumulative exposure to elevated plasma concentrations of both Lp(a) and low-density lipoprotein is particularly detrimental and explains the enhanced morbidity and mortality risk observed in patients with both conditions. An excellent opportunity to identify at-risk patients with hyper-Lp(a) at increased risk of ASCVD is to test for hyper-Lp(a) during cascade testing for FH. With probands having FH and hyper-Lp(a), the yield of detection of hyper-Lp(a) is 1 individual for every 2.1-2.4 relatives tested, whereas the yield of detection of both conditions is 1 individual for every 3-3.4 relatives tested. In this article, we discuss the incorporation of assessment of Lp(a) in the cascade testing in FH as a feasible and crucial part of models of care for FH. We also propose a simple management tool to help physicians identify and manage elevated Lp(a) in FH, with implications for the care of Lp(a) beyond FH, noting that the clinical use of RNA therapeutics for specifically targeting the overproduction of Lp(a) in at risk patients is still under investigation.

Nutrition and physical activity intervention for families with familial hypercholesterolaemia: protocol for a pilot randomised controlled feasibility study

Background

Untreated heterozygous familial hypercholesterolaemia (FH) causes high low-density lipoprotein cholesterol (LDL-C) levels and increased cardiovascular disease (CVD) risk. Despite pharmacological treatment, many treated individuals remain at higher CVD risk than non-affected individuals. This may be due to LDL-C targets not being met and presence of other CVD risk factors. Adhering to dietary and physical activity (PA) recommendations developed for individuals with FH may further reduce CVD risk. However, there is insufficient research to support the efficacy of adhering to these guidelines on LDL-C and other CVD risk factors. The need for studies to investigate the effectiveness of nutrition and PA interventions in the FH population has been widely recognised and recommended. This paper describes the protocol of a pilot, randomised controlled trial designed to evaluate the feasibility and acceptability of a specifically developed nutrition and PA intervention aimed at improving the dietary intakes and PA levels of families with FH.

Methods

A two-arm randomised waitlist-controlled pilot trial will be conducted across three National Health Service (NHS) sites in England, UK. Twenty-four young people with FH, aged 10-18 years, and their affected parent, will be recruited and randomly assigned to the intervention or waitlist and usual care control. The primary aim is to provide evidence for the feasibility and acceptability of delivering the intervention, explored quantitatively (rates of recruitment, retention and outcome measure completeness) and qualitatively (qualitative interviews). The secondary aim is to provide evidence for the potential efficacy of the intervention on dietary intake, PA, sedentary time, body composition, CVD risk factors and quality of life determined at baseline and endpoint assessments. The intervention will involve an hour-long consultation with a dietitian at baseline and four follow-up contacts across the 12-week intervention. It has been specifically developed for use with individuals with FH and incorporates behavioural change techniques to target identified enablers and barriers to adherence in this population.

Discussion

This trial will estimate the feasibility and acceptability of the nutrition and PA intervention delivered to young people and parents with FH. If appropriate, this study can be used to inform the design of an adequately powered definitive trial.

Trial registration

ISRCTN, ISRCTN24880714. Registered 07/06/2018, http://www.isrctn.com/ISRCTN24880714.

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.