Prise en charge des hypercholestérolémies de l’enfant : recommandations du Comité de nutrition de la Société française de pédiatrie et de la Nouvelle société française d’athérosclérose

Genetic and molecular architecture of familial hypercholesterolemia

Atherosclerotic cardiovascular disease is the leading cause of death globally. Despite its important risk of premature atherosclerosis and cardiovascular disease, familial hypercholesterolemia (FH) is still largely underdiagnosed worldwide. It is one of the most frequently inherited diseases due to mutations, for autosomal dominant forms, in either of the LDLR, APOB, and PCSK9 genes or possibly a few mutations in the APOE gene and, for the rare autosomal forms, in the LDLRAP1 gene. The discovery of the genes implicated in the disease has largely helped to improve the diagnosis and treatment of FH from the LDLR by Brown and Goldstein, as well as the introduction of statins, to PCSK9 discovery in FH by Abifadel et al., and the very rapid availability of PCSK9 inhibitors. In the last two decades, major progress has been made in clinical and genetic diagnostic tools and the therapeutic arsenal against FH. Improving prevention, diagnosis, and treatment and making them more accessible to all patients will help reduce the lifelong burden of the disease.

Intermediate-Term Efficacy and Tolerance of Statins in Children

OBJECTIVES

To evaluate the intermediate-term efficacy and tolerance of statins in children and adolescents with familial hypercholesterolemia.

STUDY DESIGN

A total of 131 children or adolescents treated with statins for familial hypercholesterolemia were prospectively included. The efficacy of treatment was established by the percentage of children who achieved low density lipoprotein-cholesterol (LDL-C) levels <160 mg/dL during treatment. Treatment tolerance was evaluated by the occurrence of clinical or laboratory side effects, regularity of increases in height and weight, and pubertal development.

RESULTS

The median duration of treatment with statins was 4 years. A median decrease of 32% in LDL-C levels was observed (P < .0001). The therapeutic target (LDL-C <160 mg/dL) was achieved in 67% of cases. Increases in height and weight and sexual maturation were not affected by the treatment. Minor side effects were reported for 24 (18.4%) patients including 3 cases of a clinically asymptomatic increase in creatine phosphokinase (CPK) levels, 2 cases of an increase in CPK levels with muscular symptoms, 14 cases of myalgia without an increase in CPK levels, 3 cases of abdominal pain, 1 case of dysuria, and 1 case of diffuse pain. None of these side effects led to the discontinuation of statin therapy, although a change of statin was required in 7 cases. This new statin was tolerated in all cases. No patients had abnormal liver function during treatment.

CONCLUSIONS

The results of this large cohort confirm the intermediate-term safety and efficacy of statin therapy in children with familial hypercholesterolemia.

Childhood/adult-onset lysosomal acid lipase deficiency: A serious metabolic and vascular phenotype beyond liver disease-four new pediatric cases

BACKGROUND

The childhood/adult-onset lysosomal acid lipase deficiency (LALD; late-onset LALD) is a rare genetic disease. Children present severe fatty liver disease with early cirrhosis. Before enzyme replacement therapy, statins were the standard treatment to improve the severe dyslipidemia. However, late-onset LALD should be considered as a systemic metabolic disease: chronic hyper-low-density lipoprotein and hypo-high-density lipoprotein cholesterolemia induces early atherosclerosis in addition to the liver morbidity.

OBJECTIVE

To assess 4 new pediatric cases of late-onset LALD with an evaluation of hepatic, metabolic, and vascular evolution under statin.

METHODS

Four patients were retrospectively described. Anthropometric data (weight, height, and body mass index) and laboratory data (LIPA mutations, acid lipase residual activity, liver and lipid profile, and homeostatic model assessment index) were collected. Liver histology was assessed by the noninvasive tests FibroScan and FibroTest and confirmed by liver biopsy. Vascular impact was followed up by carotid intima-media thickness (cIMT) assessment.

RESULTS

The 4 cases of late-onset LALD came from 2 families, each with a boy (aged 8.6 and 11 years at diagnosis) and a girl (aged 10.6 and 13 years at diagnosis). Treatment with statins was performed for 8 and 5 years, respectively, from diagnosis. Statins decreased the low-density lipoprotein cholesterol mean value of 40%. All children showed significant liver fibrosis (F3 [n = 3]; F2 [n = 1]). cIMT showed the following for all children: abnormal measures without improvement and atherosclerotic plaques. One child developed a deleterious metabolic phenotype with obesity and insulin resistance (homeostatic model assessment = 3.08) associated with higher mean hepatic transaminases (149 vs 98, 88, and 61 IU/L) and increased mean cIMT values (raising from 0.47 to 0.5 mm vs 0.43 and 0.43 mm).

CONCLUSION

Late-onset LALD is a rare metabolic disease with a larger impact than liver disease. Our work shows the importance of having a global metabolic view and to evaluate the cardiovascular impact of the new enzymatic treatment.

Hypercholesterolemia--a disease with expression from childhood

INTRODUCTION

Hypercholesterolemia results from an alteration, genetic or acquired, in lipoprotein metabolism. Evidence that hypercholesterolemia is associated with the atherosclerotic process from childhood justifies the screening of high-risk children and initiation of therapy at preschool ages.

OBJECTIVE

To assess children referred for pediatric consultations due to hypercholesterolemia.

METHODS

Children and adolescents referred for pediatric consultations with a diagnosis of hypercholesterolemia were enrolled. Information on family history and clinical, anthropometric and biochemical parameters was recorded and, when appropriate, molecular study was performed.

RESULTS

A total of 168 children were assessed. Forty-six presented a familial hypercholesterolemia phenotype and in 22 of these, a mutation in the low-density lipoprotein (LDL) receptor gene was identified. The lipid profile of the group with mutations showed significantly higher values of total and non-high-density lipoprotein (HDL) cholesterol compared to the group without mutations (total cholesterol 316.5±75.9 mg/dl vs. 260.9±42,0 mg/dl; non-HDL cholesterol 268.3±72.6 mg/dl vs. 203.5±43.9 mg/dl; p<0.05). Of the total, 55 were prescribed pharmacological therapy and the others underwent diet and exercise interventions only. A greater reduction in LDL cholesterol was observed in individuals under pharmacological therapy compared to those prescribed diet and exercise only (30.3% vs. 18.1%). Drug side effects were insignificant.

CONCLUSION

It is possible to maintain a normal lipid profile in most individuals with familial hypercholesterolemia in order to reduce the risk of early onset of atherosclerosis, which is associated with serious cardiovascular complications from childhood.