2024 KSoLA consensus on secondary dyslipidemia.

Elevated blood cholesterol and triglyceride levels induced by secondary causes are frequently observed. The identification and appropriate handling of these causes are essential for secondary dyslipidemia treatment. Major secondary causes of hypercholesterolemia and hypertriglyceridemia include an unhealthy diet, diseases and metabolic conditions affecting lipid levels, and therapeutic side effects. It is imperative to correct secondary causes prior to initiating conventional lipid-lowering therapy. Guideline-based lipid therapy can then be administered based on the subsequent lipid levels.

Cardiovascular Risk Estimation and Stratification Among Individuals with Hypercholesterolemia.

PURPOSE OF THE REVIEW: This review aims to assess the variability in considering hypercholesterolemia for cardiovascular risk stratification in the general population. Recent literature on the integration of hypercholesterolemia into clinical risk scores and its interaction with other risk factors will be explored. RECENT FINDINGS: The impact of hypercholesterolemia on risk estimation varies among different cardiovascular risk calculators. Elevated lipid levels during early life stages contribute to atherosclerotic plaque development, influencing disease severity despite later treatment initiation. The interplay between low-density lipoprotein cholesterol (LDLc), inflammatory markers and non-LDL lipid parameters enhances cardiovascular risk stratification. Studies have also examined the role of coronary artery calcium (CAC) score as a negative risk marker in populations with severe hypercholesterolemia. Furthermore, polygenic risk scores (PRS) may aid in diagnosing non-monogenic hypercholesterolemia, refining cardiovascular risk stratification and guiding lipid-lowering therapy strategies. Understanding the heterogeneity in risk estimation and the role of emerging biomarkers and imaging techniques is crucial for optimizing cardiovascular risk prediction and guiding personalized treatment strategies in individuals with hypercholesterolemia.

Dried blood spot-based free sterol signatures in sitosterolemia diagnostics.

BACKGROUND: Sitosterolemia is a rare inherited lipid metabolic disorder characterized by increased levels of plant sterols and accelerated atherosclerosis. Although early detection is beneficial for the prevention of disease progression, it is largely underdiagnosed by routine screening based on conventional lipid profiles. MATERIALS AND METHODS: A gas chromatography-mass spectrometry (GC-MS)-based profiling has been developed and validated to measure the levels of biologically active free sterols, including five endogenous sterols and three plant sterols (sitosterol, campesterol, and stigmasterol) in dried blood spot (DBS). RESULTS: Within- and between-run precisions were 1.4-11.1 % and 2.2-14.1 %, respectively, while the accuracies were all 86.3 âˆ¼ 121.9 % with the correlation coefficients (r2) > 0.988 for all the sterols. In the patients (four girls and two boys, 6.5 ± 2.8 years), sitosterol levels were significantly increased, with an optimal cut-off value of 2.5 µg/mL distinguishing them from ninety-three age-matched healthy children. A cut-off value of 31.9 µg/mL differentiated the patients from six ABCG5/ABCG8 heterozygous carriers. In addition, the molecular ratios of sitosterol to cholesterol, desmosterol, and 7-dehydrocholesterol provided excellent cut-off values of 26.3, 67.6, and 21.6, respectively, to distinguish patients from both healthy controls and heterozygous carriers. CONCLUSIONS: The novel DBS-based GC-MS profiling of free sterols accurately identified patients with sitosterolemia, with a performance comparable to that of a serum assay. The DBS profiling could be more feasible method in clinical practice as well as population screening programs, and it can provide diagnostic cut-off values for individual plant sterols.

Efficacy and safety of ongericimab given by prefilled syringe or autoinjector in primary hypercholesterolemia and mixed hyperlipidemia.

BACKGROUND AND AIMS: Limited evidence exist regarding the association between ongericimab, a novel recombinant humanized anti-PCSK9 monoclonal antibody, and primary hypercholesterolemia and mixed dyslipidemia. This study aimed to evaluate the efficacy and safety of ongericimab administered by prefilled syringe (PFS) or autoinjector (AI) in Chinese patients with primary hypercholesterolemia and mixed dyslipidemia on stable optimized lipid-lowering therapy. METHODS AND RESULTS: A total of 255 patients on stable optimized lipid-lowering therapy were randomized in a 2:1:2:1 ratio to receive PFS for the subcutaneous injection of ongericimab 150 mg every 2 weeks (Q2W) or a matching placebo, or AI for the subcutaneous injection of ongericimab 150 mg Q2W or a matching placebo. The primary efficacy endpoint was the percent change in low-density lipoprotein cholesterol (LDL-C) levels from baseline to week 12. Safety was also evaluated. At week 12, the least squares mean percent changes were -72.7% (3.9%) for PFS and -71.1% (3.8%) for AI (all P < 0.001) compared to respective matching placebo groups. Beneficial effects were also seen for all secondary lipid parameters, notably with robust reduction in Lp (a). Treatment-emergent adverse events (TEAEs) and serious AEs with ongericimab were reported in 46.2% and 2.4% of patients, compared to 44.2% and 3.5% with placebo. CONCLUSION: In Chinese patients with primary hypercholesterolemia and mixed dyslipidemia, a 12-week treatment regimen with ongericimab administered by PFS or AI significantly reduced LDL-C and other lipid parameters, proving to be safe and well tolerated. Patients experienced consistent effects from PFS or AI devices. CLINICAL TRIAL REGISTRATION: CTR20220027; January 11, 2022; http://www.chinadrugtrials.org.cn/index.html.

Short-term effects of gastric bypass versus sleeve gastrectomy on high LDL cholesterol: The BASALTO randomized clinical trial.

BACKGROUND: There has been a substantial increase in the use of laparoscopic sleeve gastrectomy (SG) to treat morbid obesity despite observational evidence demonstrating the superiority of Roux-en-Y gastric bypass (RYGB) for reducing low-density lipoprotein (LDL) cholesterol. The main aim was to ascertain whether high LDL cholesterol levels should be considered when selecting the most appropriate surgical procedure for each patient (RYGB or SG). METHODS: In this single-center, randomized clinical trial using intention-to-treat analysis, 38 patients with severe obesity and elevated levels of LDL cholesterol were randomly assigned to undergo RYGB or SG. The primary outcome was LDL cholesterol remission at 12 months, defined as LDL cholesterol < 3.36 nmol/l without lipid-lowering medications. Secondary outcomes included changes in weight, other comorbidities, qualitative lipoprotein traits, cholesterol esters, glycoproteins, cholesterol absorption and synthesis metabolites and complications. RESULTS: Intention-to-treat analysis revealed that LDL cholesterol remission occurred in 66.6% of RYGB patients compared to 27.8% of SG patients (p = 0.019). Among patients completing follow-up, RYGB demonstrated superior remission (80.0% vs. 29.4%, p = 0.005). Exclusive benefits of RYGB included a reduction in large, medium, and small LDL particles. Cholesterol absorption markers showed differential behavior after both techniques: campesterol (Δ -15.2 µg/mg, 95% CI -30.2 to -0.1) decreased after RYGB, and sitosterol (Δ 21.1 µg/mg, 95% CI 0.9 to 41.2), cholestanol (Δ 30.6 µg/mg, 95% CI 14.8 to 57.9) and campesterol (Δ 18.4 µg/mg, 95% CI 4.4 to 32.3) increased after SG. No differences in weight loss, cholesterol esters, glycoproteins, cholesterol synthesis metabolites or postoperative complications were observed between techniques. CONCLUSION: In conclusion, RYGB is superior to SG in terms of short-term of high LDL cholesterol remission. Furthermore, RYGB also led to a greater improvement in lipoprotein parameters that confer an atherogenic profile. Therefore, the presence of elevated levels of LDL cholesterol should be considered when determining the optimal bariatric surgery procedure for each patient. TRIAL REGISTRATION: Clinicaltrials.gov number, NCT03975478).

Efficacy and Safety of Ongericimab in Chinese Patients With Primary Hypercholesterolemia and Mixed Dyslipidemia.

BACKGROUND: A phase 3 trial was conducted to evaluate the efficacy and safety of ongericimab, a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9, as an add-on treatment to optimized lipid-lowering therapy in Chinese patients with primary hypercholesterolemia and mixed dyslipidemia. METHODS AND RESULTS: A total of 806 patients who were receiving stable and optimized lipid-lowering therapy but did not achieve their low-density lipoprotein cholesterol (LDL-C) targets were enrolled and randomly assigned in a 2:1:2:1 ratio to receive either ongericimab 150 mg or matching placebo every 2 weeks, or ongericimab 300 mg or matching placebo every 4 weeks for 52 weeks. Efficacy and safety were evaluated in 802 patients who received at least 1 dose of ongericimab or placebo. The primary end point was the percentage change in LDL-C from baseline to week 24. Our findings demonstrated that the least-squares mean difference of percentage change in LDL-C from baseline to week 24 was -67.7% (95% CI, -72.5% to -63.0%; P<0.0001) in the ongericimab 150 mg every 2 weeks group compared with the placebo every 2 weeks group, and -61.2% (95% CI, -67.1% to -55.2%; P<0.0001) in the ongericimab 300 mg every 4 weeks group compared with the placebo every 4 weeks group. These reductions were sustained up to week 52. Furthermore, treatment with ongericimab favorably altered other lipid parameters. A similar incidence of adverse events was observed in the ongericimab and placebo groups. CONCLUSIONS: Ongericimab, as an add-on treatment to optimized lipid-lowering therapy, significantly reduced LDL-C and was well-tolerated in Chinese patients with primary hyperlipidemia and mixed dyslipidemia who did not achieve their LDL-C targets. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04781114.

Targeting PCSK9 as a key player in lipid metabolism: exploiting the therapeutic and biosensing potential of aptamers.

The degradation of low-density lipoprotein receptor (LDLR) is induced by proprotein convertase subtilisin/kexin type 9 (PCSK9), resulting in elevated plasma concentrations of LDL cholesterol. Therefore, inhibiting the interactions between PCSK9 and LDLR is a desirable therapeutic goal for managing hypercholesterolemia. Aptamers, which are RNA or single-stranded DNA sequences, can recognize their targets based on their secondary structure. Aptamers exhibit high selectivity and affinity for binding to target molecules. The systematic evolution of ligands by exponential enrichment (SELEX), a combination of biological approaches, is used to screen most aptamers in vitro. Due to their unique advantages, aptamers have garnered significant interest since their discovery and have found extensive applications in various fields. Aptamers have been increasingly utilized in the development of biosensors for sensitive detection of pathogens, analytes, toxins, drug residues, and malignant cells. Furthermore, similar to monoclonal antibodies, aptamers can serve as therapeutic tools. Unlike certain protein therapeutics, aptamers do not elicit antibody responses, and their modified sugars at the 2'-positions generally prevent toll-like receptor-mediated innate immune responses. The focus of this review is on aptamer-based targeting of PCSK9 and the application of aptamers both as biosensors and therapeutic agents.

Family sitosterolemia: report of two cases in Colombia. / Sitosterolemia familiar: reporte de dos casos en Colombia.

Sitosterolemia is an autosomal recessive and very rare disease. Its main characteristic is that there is a greater absorption and a decrease in the excretion of sterols, which leads to them being deposited in tissues. It is given by mutations in the ABCG5 or ABCG8 genes found on chromosome 2p21. In this clinical note, we describe the first two patients with familial sitosterolemia described in Colombia, brothers, one of them with xanthomas in extremities as the only symptom, and the other, completely asymptomatic. Genetic studies were performed as a diagnostic test in both patients, where a pathogenic homozygous variant could be identified in the ABCG8 gene in the first case (symptomatic), and a heterozygous variant in the ABCG8 gene in the second case (asymptomatic); the first patient has responded to treatment with ezetimibe. In conclusion, xanthomas should be studied in depth in pediatric age as they may be the only visible sign of such complex and hereditary diseases as familial sitosterolemia, which can be controlled and prevent cardiovascular complications of the disease.

[Child with sitosterolemia initially presenting with hemolytic anemia and thrombocytopenia: a case repore and literrature review].

This article focuses on a case study of sitosterolemia in a child who initially presented with hemolytic anemia and thrombocytopenia. Sitosterolemia is a rare autosomal recessive lipid metabolism disorder, difficult to diagnose due to its non-typical clinical manifestations. The 8-year-old patient was initially misdiagnosed with pyruvate kinase deficiency. Comprehensive biochemical and molecular biology analyses, including gene sequencing, eventually led to the correct diagnosis of sitosterolemia. This case highlights the complexity and diagnostic challenges of sitosterolemia, emphasizing the need for increased awareness and accurate diagnosis in patients presenting with similar symptoms.

Identification of multiple plasma lipids as diagnostic biomarkers of hypercholesterolemia and the underlying mechanisms based on pseudo-targeted lipidomics.

RATIONALE: Hypercholesterolemia is an important risk factor for cardiovascular diseases and death. This study performed pseudo-targeted lipidomics to identify differentially expressed plasma lipids in hypercholesterolemia, to provide a scientific basis for the diagnosis and pathogenesis of hypercholesterolemia. METHODS: Pseudo-targeted lipidomic analyses of plasma lipids from 20 patients with hypercholesterolemia and 20 normal control subjects were performed using liquid chromatography-mass spectrometry. Differentially expressed lipids were identified by principal component analysis and orthogonal partial least squares discriminant analysis. Receiver operating characteristic curves were used to identify differentially expressed lipids with high diagnostic value. The Kyoto Encyclopedia of Genes and Genomes pathway database was used to identify enriched metabolic pathways. RESULTS: We identified 13 differentially expressed lipids in hypercholesterolemia using variable importance of projection > 1 and p < 0.05 as threshold parameters. The levels of eight sphingomyelins and cholesterol sulfate were higher and those of three triacylglycerols and lysophosphatidylcholine were reduced in hypercholesterolemia. Seven differentially expressed plasma lipids showed high diagnostic value for hypercholesterolemia. Functional enrichment analyses showed that pathways related to necroptosis, sphingolipid signaling, sphingolipid metabolism, and steroid hormone biosynthesis were enriched. CONCLUSIONS: This pseudo-targeted lipidomics study demonstrated that multiple sphingomyelins and cholesterol sulfate were differentially expressed in the plasma of patients with hypercholesterolemia. We also identified seven plasma lipids, including six sphingomyelins and cholesterol sulfate, with high diagnostic value.

Monitoring and treatment of hypercholesterolemia after an atherosclerotic cardiovascular disease event in Denmark from 2015 to 2020.

BACKGROUND AND AIMS: Lowering the blood concentration of low-density lipoprotein cholesterol (LDL-C), is a cornerstone in preventing atherosclerotic cardiovascular disease (ASCVD). Current European guidelines recommends LDL-C < 1.4 mmol/L for secondary prevention in high-risk patients. The aim of this study is to investigate monitoring and treatment of hypercholesterolemia one year after a ASCVD event. METHODS: Danish patients with hypercholesterolemia and an incident ASCVD event from 2015 to 2020 were included in this nationwide cohort study. Patients' LDL-C measurements and lipid-lowering treatment were followed for one year after ASCVD event, or until death or migration. Imputation was used to estimate absolute LDL-values when patients were unmeasured. RESULTS: A total of 139,043 patients were included in the study with a mean follow-up time of 10.4 months. During the one-year period, 120,020 (86%) patients had their LDL-C measured at least once, 83,723 (60%) patients were measured at least twice. During the period one to six months after ASCVD event 25,999 (19%) achieved an LDL-C < 1.4 mmol/L, 93,349 (67%) failed to achieve an LDL-C < 1.4 mmol/L, and 196,950 (14%) had died or migrated. Missing LDL-C values were estimated via imputation. At the end of month twelve, 60,583 (44%) patients were in statin monotherapy, 2926 (2%) were treated with other lipid-lowering treatment, 42,869 (31%) were in no treatment, and 32,665 (23%) had died or migrated. CONCLUSIONS: Many Danish patients are not appropriately followed-up with LDL-C measurements, and a substantial number of patients are not in lipid-lowering treatment one year after an ASCVD event.

Inhibition of Proprotein Convertase Subtilisin/Kexin-9 After Kidney Transplant: Single-Center Experience Among Patients With High Cardiovascular Risk.

OBJECTIVES: The benefits of reduction in low-density lipoprotein cholesterol by evolocumab by nearly 60% has not been evaluated among kidney transplant recipients to our knowledge. We assessed the efficacy and safety of evolocumab, a proprotein convertase subtilisin/kexin-9 inhibitor, in reducing lipids and cardiovascular events among kidney transplant recipients in a randomized controlled study. MATERIALS AND METHODS: Between June 2017 and June 2019, we enrolled 197 kidney transplant recipients with high cardiovascular risk score (>20). Patients who received evolocumab (140 mg/2 weeks) comprised group 1 (n = 98), and patients maintained on statin therapy comprised group 2 (n = 99). We followed patients clinically and with necessary laboratory investigations over 24 months. RESULTS: The 2 groups had comparable demographic characteristics (P > .05). Before enrollment in the study, smokers were significantly more prevalent in group 1, whereas posttransplant diabetes mellitus was more prevalent in group 2 (P = .033). Moreover, baseline serum creatinine was higher in group 1, whereas immunosuppression was equivalent in both groups (P > .05). We found no significant differences between the 2 groups concerning cardiovascular events, and both graft and patient outcomes were comparable (P > .05). The higher baseline cholesterol in group 1 (5.5 vs 4.7 mmol/L; P < .001) decreased significantly after 3 months and thereafter (P = .031) compared with levels in group 2 and baseline values (P < .001). We reported 2 cases of acute myocardial infarction and 1 atrial fibrillation in group 2. CONCLUSIONS: Proprotein convertase subtilisin/kexin-9 inhibitors, as an added therapy to statins, are safe and effective in treating hypercholesterolemia after kidney transplant. Evolocumab can minimize cardiovascular events after kidney transplant in patients with high events at baseline. Longer-term trials with larger number of patients are needed to confirm its beneficial effects on cardiovascular complications and patient and graft survival.

Dietary cholesterol intake is not associated with the development of chronic kidney disease: Results from two Korean cohort studies.

BACKGROUND AND AIMS: Although dyslipidemia is a major risk factor for chronic kidney disease (CKD), the relationship between dietary cholesterol and CKD remains unknown. We investigated the association between cholesterol intake and CKD risk. METHODS AND RESULTS: The Korea National Health and Nutrition Examination Survey (KNHANES) 2019-2021 (n = 13,769) and the Korean Genome and Epidemiology Study (KoGES) (n = 9225) data were used for this study. Cholesterol intake was assessed using a 24-h recall food frequency questionnaire, and participants were categorized into three groups (T1, T2, and T3) based on cholesterol intake. Primary outcomes were prevalence and incidence of CKD. Higher cholesterol intake was modestly associated with increased serum levels of total, low-density lipoprotein, and high-density lipoprotein cholesterol in the KNHANES. However, we found no significant association between cholesterol intake and CKD prevalence in the KNHANES, regardless of a history of hypercholesterolemia. In the KoGES, during a median follow-up of 11.4 years, cholesterol intake was not associated with incident CKD in participants without hypercholesterolemia (hazard ratio [HR] per 10 mg increase, 1.00; 95 % confidence interval [CI], 0.99-1.01) and in those with hypercholesterolemia (HR, 1.01; 95 % CI, 0.98-1.04). Egg consumption also showed no significant association with the risk of incident CKD. Additionally, cholesterol intake had no significant interaction on the relationships between serum cholesterol levels and incident CKD. CONCLUSION: Although cholesterol intake was associated with increased serum cholesterol levels, it was not associated with CKD prevalence and incidence. Our findings suggest that reducing cholesterol intake alone may not be sufficient to prevent CKD.

Establishing a multi-specialty consensus in the clinical need for hypercholesterolemia management and its implication for patients access to innovative therapies.

BACKGROUND: Increased level of blood LDL-C has a causal and cumulative effect on advancing atherosclerotic cardiovascular diseases (ASCVD). European guidelines for treating high LDL-C levels have been recently updated. However, in France, several challenges (e.g., physician and patient awareness, healthcare management) limit the application of management guidelines. The aim of this study was to understand the current opinions and perceived unmet clinical needs in recognising and managing hypercholesterolemia as an ASCVD risk factor, and to explore consensus around factors that support the effective management of elevated LDL-C. METHODS: An expert group of cardiologists, endocrinologists, biology/genetics researchers, and a health technology assessments expert, from France was convened. The current management of hypercholesterolemia and barriers to achieving LDL-C goals in France were discussed and 44 statements were developed. Wider consensus was assessed by sending the statements as a 4-point Likert Scale questionnaire to cardiologists and endocrinologists across France. The consensus threshold was defined as ≥75%. RESULTS: A total of 101 responses were received. Consensus was very high (>90%) in 25 (57%) statements, high (≥75%) in 18 (41%) statements and was not achieved (<75%) only in 1 (2%) of statements. Overall, 43 statements achieved consensus. CONCLUSIONS: Based on consensus levels, key recommendations for improving current guidelines and approaches to care have been developed. Implementation of these recommendations will lead to better concordance with international treatment guidelines and increase levels of education for healthcare practitioners and patients. In turn, this will improve the available treatment pathways for cardiovascular diseases, potentially creating improved patient outcomes in the future.

Clinical characteristics and treatment patterns in patients with atherosclerotic cardiovascular disease with hypercholesterolemia: a retrospective analysis of a large US real-world database cohort.

OBJECTIVE: Guidelines developed by the American College of Cardiology/American Heart Association (ACC/AHA) recommend lipid-lowering therapies (LLTs) to reduce low-density lipoprotein cholesterol (LDL-C) and atherosclerotic cardiovascular disease (ASCVD) risk. This study described LLT utilization patterns and LDL-C goal achievement (to <70 mg/dL) among patients with ASCVD in the United States. METHODS: This retrospective study was conducted using Optum's de-identified Clinformatics Data Mart Database (CDM). Patients with their first ASCVD diagnosis (index date) in the CDM database between July 1, 2015, and December 31, 2018, were followed for ≥12 months to assess LLT utilization patterns and change in LDL-C. LLTs included were statins and non-statin LLTs (ezetimibe, fibrates, and proprotein convertase subtilisin/kexin type 9 inhibitors). Adherence was measured as the proportion of days covered (PDC), defined as the number of days with drug on-hand (or number of days exposed to drug) divided by the 12-month follow-up period. Patients with PDC ≥0.8 were considered adherent. RESULTS: Among the patients with ASCVD (N = 1,424,893) included in this study, only 621,978 (43.7%) had at least one LDL-C measurement at baseline (6 months prior to and 3 months after the index date). The mean age was 71.5 years, and almost half of the patients were female. Patients were followed for a mean (standard deviation [SD]) duration of 30.6 (11.4) months (median of 29.9 months). During the follow-up, about one-quarter of the patients did not receive any LLT. Among treated patients, 89.5% received statins and 10.5% received non-statin LLT. Less than half (47.6%) of the patients were adherent to the index treatment during the 12-month follow-up. Even in patients receiving combination therapy (statin + non-statin LLT), a sizable proportion (35.8%) showed an increase in LDL-C over the follow-up period. CONCLUSIONS: This retrospective study highlighted limited LDL-C monitoring in patients with ASCVD, and unmet need in terms of suboptimal utilization of non-stain LLTs, limited adherence to LLTs, and inadequate lipid control after treatment (among those with LDL-C measurements during the follow-up period) need to be addressed to improve outcomes in this patient cohort.

International societies of cardiologists recommend use of medications to lower the "bad" cholesterol, and its risk of cardiovascular diseases like stroke. We aimed to describe how those medications are being used and to what extent patients with cardiovascular diseases in the United States have their "bad" cholesterol under control. Results of this study indicate that cholesterol check-up among the patients was limited. Among recommended medications, statins were mostly used, whereas use of other recently approved medications was minimal. One-quarter of patients were not prescribed medications to control their cholesterol. Moreover, patients were not taking the medications as frequently as prescribed.

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study.

BACKGROUND: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. METHODS: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. FINDINGS: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. INTERPRETATION: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life. FUNDING: Pfizer, Amgen, Merck Sharp & Dohme, Sanofi-Aventis, Daiichi Sankyo, and Regeneron.