Screening for Lipid Disorders in Children and Adolescents: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

"I don't think people should die young": perspectives of parents with children diagnosed with familial hypercholesterolemia

Familial Hypercholesterolemia (FH) is an inherited disorder that significantly increases an individual's risk of developing premature cardiovascular disease (CVD). Early intervention involving lifestyle modification and medication is crucial in preventing CVD. Prior studies have shown that lipid-lowering therapy in children is safe and effective. Despite FH being a treatable and manageable condition, the condition is still underdiagnosed and undertreated. Universal lipid screening (ULS) in children has been recommended by some medical experts in the United States as a strategy to identify cases of FH and maximize the benefits of early invention. However, lipid screening is not routinely offered in pediatric clinics. This study aimed to explore parental experience with FH diagnosis in their children, identify key facilitators and barriers in children's diagnosis and care, and examine parental perspectives on ULS in children in the United States. A total of fourteen semi-structured interviews were conducted with participants recruited through the Family Heart Foundation. Thematic analysis identified three key themes: role of family history in facilitating child's FH diagnosis, barriers and challenges in post-diagnosis care, and attitudes towards ULS in children. All participants supported ULS in children and emphasized the value of early diagnosis and treatment for FH. However, a lack of guidance or referral after the child's diagnosis was a concern raised by many participants. This underscores the need for accessible and comprehensive care amid ongoing efforts to increase pediatric diagnosis of FH.

Plasma lipids paediatric reference intervals: Indirect estimation using a large 14-year database

OBJECTIVES

Establishing direct reference intervals (RIs) for paediatric patients is a very challenging endeavour. Indirect RIs can address this problem, using existing clinical laboratory databases from real-world data research. Compared to the traditional direct method, the indirect approach is highly practical, widely applicable, and low-cost. Considering the relevance of dyslipidemia in the paediatric age, to provide better laboratory services to the local paediatric population, we established population-specific lipid RIs via data mining.

METHODS

Our laboratory information system was searched for cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) of patients aged less than 18 years, performed from January 2009 until December 2022. RIs were estimated using RefineR algorithm.

RESULTS

Values from 215,594 patients were initially collected. After refining data on the basis of specific exclusion criteria that left 17,933 patients, we determined the RIs for each analyte, including corresponding 95% confidence interval (95% CI). Age and sex partitions were required for proper stratification of the heterogenous subpopulations. Age-related variations in TC and TG values were observed mainly in children until 5 years. RIs were defined for children less than 3 years and for those of 3-18 years. In our population, the obtained RIs were comparable with those of the literature, but the upper TG limit in subjects under the age of 3 (2.03 mmol/L with 95% CI: 1.45-2.86) was lower than that previously reported.

CONCLUSIONS

Our RIs, necessary for paediatric lipid monitoring, are tailored to the serviced patient population as should be done whenever possible.

Pediatric Lipid Screening Prevalence Using Nationwide Electronic Medical Records

Importance

Universal screening to identify unfavorable lipid levels is recommended for US children aged 9 to 11 years and adolescents aged 17 to 21 years (hereafter, young adults); however, screening benefits in these individuals have been questioned. Current use of lipid screening and prevalence of elevated lipid measurements among US youths is not well understood.

Objective

To investigate the prevalence of ambulatory pediatric lipid screening and elevated or abnormal lipid measurements among US screened youths by patient characteristic and test type.

Design, Setting, and Participants

This cross-sectional study used data from the IQVIA Ambulatory Electronic Medical Record database and included youths aged 9 to 21 years with 1 or more valid measurement of height and weight during the observation period (2018-2021). Body mass index (BMI) was calculated and categorized using standard pediatric BMI percentiles (9-19 years) and adult BMI categories (≥20 years). The data were analyzed from October 6, 2022, to January 18, 2023.

Main Outcomes and Measures

Lipid measurements were defined as abnormal if 1 or more of the following test results was identified: total cholesterol (≥200 mg/dL), low-density lipoprotein cholesterol (≥130 mg/dL), very low-density lipoprotein cholesterol (≥31 mg/dL), non-high-density lipoprotein cholesterol (≥145 mg/dL), and triglycerides (≥100 mg/dL for children aged 9 years or ≥130 mg/dL for patients aged 10-21 years). After adjustment for age group, sex, race and ethnicity, and BMI category, adjusted prevalence ratios (aPRs) and 95% CIs were calculated.

Results

Among 3 226 002 youths (23.9% aged 9-11 years, 34.8% aged 12-16 years, and 41.3% aged 17-21 years; 1 723 292 females [53.4%]; 60.0% White patients, 9.5% Black patients, and 2.4% Asian patients), 11.3% had 1 or more documented lipid screening tests. The frequency of lipid screening increased by age group (9-11 years, 9.0%; 12-16 years, 11.1%; 17-21 years, 12.9%) and BMI category (range, 9.2% [healthy weight] to 21.9% [severe obesity]). Among those screened, 30.2% had abnormal lipid levels. Compared with youths with a healthy weight, prevalence of an abnormal result was higher among those with overweight (aPR, 1.58; 95% CI, 1.56-1.61), moderate obesity (aPR, 2.16; 95% CI, 2.14-2.19), and severe obesity (aPR, 2.53; 95% CI, 2.50-2.57).

Conclusions and Relevance

In this cross-sectional study of prevalence of lipid screening among US youths aged 9 to 21 years, approximately 1 in 10 were screened. Among them, abnormal lipid levels were identified in 1 in 3 youths overall and 1 in 2 youths with severe obesity. Health care professionals should consider implementing lipid screening among children aged 9 to 11 years, young adults aged 17 to 21 years, and all youths at high cardiovascular risk.

LDLR c.89_92dup: a novel frameshift variation in familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is a common inherited metabolic disease that causes premature atherosclerosis, cardiovascular disease, and even death at a young age. Approximately 95% of FH-causing genetic variants that have been identified are in the LDLR gene. However, only 10% of the FH population worldwide has been diagnosed and adequately treated, due to the existence of numerous unidentified variants, uncertainties in the pathogenicity scoring of many variants, and a substantial number of individuals lacking access to genetic testing.

OBJECTIVE

The aim of this study was to identify a novel variant in the LDLR gene that causes FH in a Chinese family, thereby expanding the spectrum of FH-causing variants.

METHODS

Patients were recruited from Beijing Anzhen Hospital, Capital Medical University. FH diagnosis was made according to the Dutch Lipid Clinical Network (DLCN) criteria. Whole-exome sequencing (WES) was conducted to identify the FH-causing variant in the proband, and amplicon sequencing was used to verify the variant in his family members.

RESULTS

A three-generation Chinese family was recruited, and two FH patients were clinically diagnosed, both without known FH-causing variants. These two FH patients and another possible patient carried a novel variant, NC_000019.9(NM_000527.5):c.89_92dup (NP_000518.1:p.Phe32Argfs*21), in the ligand-binding domain of the low-density lipoprotein (LDL) receptor that led to a frameshift. The FH adults in the family showed severe clinical symptoms and statin therapy resistance.

CONCLUSION

This study identified a novel pathogenic LDLR variant, c.89_92dup, associated with severe FH clinical manifestations and statin therapy resistance.

Universal lipid screening in adolescents to identify familial hypercholesterolemia in a large healthcare system

BACKGROUND

Familial hypercholesterolemia (FH) is an inherited condition that likely affects 1 in 300 people often requiring pharmacologic intervention in childhood.

OBJECTIVES

We hypothesized that current strategies for pediatric lipid screening fail to detect and treat most FH, but data analysis may suggest specific methods to improve outcomes.

METHODS

We retrospectively searched 392,129 patient records of 11-17-year-olds in Kaiser Permanente Southern California for data related to recommended universal pediatric lipid screening. We categorized subjects as Probable or Possible FH and evaluated FH pharmacotherapy status.

RESULTS

37% of the population received lipid screening with 0.13% (1 in 769) having Probable or Possible FH. Results at each step of the process showed progressive decreases in detection and treatment. We characterized 1 in 3448 subjects as Probable FH which is only 8.7% of cases expected from the prevalence of FH in the population. 45% of Probable FH cases received ongoing pharmacotherapy which is 1 in 7688 of the cohort (3.9% of expected cases). One major correctable reason for this drop-off was using obesity to target screening and treatment decisions rather than following the recommended universal screening. We found a strong association of obesity with screening (risk ratio (RR) 2.74 [confidence interval (CI) 2.71-2.76]), but not with FH (RR 0.72, CI 0.47-1.10).

CONCLUSION

This current universal lipid screening strategy, likely typical of US practice, fails to detect and treat the supermajority of FH cases, increasing risk for adult coronary artery disease. To address the specific deficiencies we observed, we suggest improvements to detect and treat FH.

Increasing lipids with risk of worsening cardiac damage in 1595 adolescents: A 7-year longitudinal and mediation study

BACKGROUND AND AIMS

Longitudinal evidence on the associations of changes in lipids level with changes in cardiac structure and function in youth is limited due to few repeated echocardiography measures. This study examined whether changes in lipid levels from adolescence through young adulthood associate with the risk of cardiac damage progression and potential mechanistic pathways.

METHODS

From the Avon Longitudinal Study of Parents and Children (ALSPAC), UK birth cohort, 1595 adolescents aged 17 years who had fasting plasma total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), and non-HDL-c measured at 17- and 24-year clinic visit were included. Echocardiography measured left ventricular mass indexed for height2.7 (LVMI2.7), and LV diastolic function from mitral E/A ratio (LVDF). LVMI2.7 ≥51 g/m2.7 and LVDF<1.5 were categorized as LV hypertrophy and LVD dysfunction, respectively. Multivariable adjusted associations were examined using generalized logit mixed-effect models and structural equation models for mediation analyses.

RESULTS

The prevalence of LV hypertrophy increased from 3.6% at baseline to 11.6% at follow-up in males and increased from 1.6% to 4.0% in females. The prevalence of LVD dysfunction increased from 7.8% at baseline to 16.6% at follow-up in males and increased from 10.3% to 15.4% in females. Each 1 mmol increase in total cholesterol (OR, 1.18; [95% CI, 1.09-1.27]), triglyceride (2.89; [1.54-5.43]), LDL-c (1.19; [1.08-1.32]), and non-HDL-c (1.21; [1.11-1.33]) was associated with higher odds of worsening LV hypertrophy progression over 7 years. Increased triglyceride was associated with the odds of progressively worsening LVD dysfunction (1.98; [1.06-3.71]). Increased HDL-c was not associated with the odds of cardiac structural and functional damage. Systolic blood pressure (12% mediation) and fat mass (25% mediation) partly mediated the associations of LDL-c with increased LVMI2.7.

CONCLUSIONS

Increased lipids may independently associate with the risk of progressively worsening structural and functional cardiac damage in youth but increased systolic blood pressure and fat mass explained circa forty percent of the relationship.

Comparison of Two Strategies for Hypercholesterolemia Detection through Point-of-Care Testing

BACKGROUND

Childhood dyslipidemia is a common condition that can lead to atherosclerotic cardiovascular disease in adulthood. It is usually multifactorial. Screening for cholesterol disorders in children varies based on risk factors, with some guidelines recommending cascade screening for children with a clear family history of familial hypercholesterolemia, targeted screening for those with specific risk factors, and universal screening. Point-of-care testing (POCT) cholesterol tests offer potential advantages, including ease of use, portability, increased patient access, low cost, fewer medical or laboratory visits, and instant results. This study aimed to evaluate the effect of POCT cholesterol screening on the diagnosis of hypercholesterolemia in children in a family practice setting.

METHODS

We used a POCT cholesterol analyzer to perform two different (universal and targeted) screening approaches for dyslipidemia in children. We used the NCEP guidelines for the classification of the results.

RESULTS

We screened 183 children, 105 in the universal screening group and 78 in the targeted screening group. Eight patients in the targeted screening group had elevated cholesterol levels (p = 0.02).

CONCLUSIONS

All participants received instant feedback and recommendations. Using a targeted screening approach, POCT could be a practical and effective tool for identifying at-risk children with 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.

Screening for Lipid Disorders in Children and Adolescents: US Preventive Services Task Force Recommendation Statement

Importance

Familial hypercholesterolemia and multifactorial dyslipidemia are 2 conditions that cause abnormally high lipid levels in children, which can lead to premature cardiovascular events (eg, myocardial infarction and stroke) and death in adulthood.

Objective

The US Preventive Services Task Force (USPSTF) commissioned a systematic review to evaluate the benefits and harms of screening for lipid disorders in asymptomatic children and adolescents.

Population

Asymptomatic children and adolescents 20 years or younger without a known diagnosis of a lipid disorder.

Evidence Assessment

The USPSTF concludes that the current evidence is insufficient and the balance of benefits and harms for screening for lipid disorders in asymptomatic children and adolescents 20 years or younger cannot be determined.

Recommendation

The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for lipid disorders in children and adolescents 20 years or younger. (I statement).