Rational approach to the treatment for heterozygous familial hypercholesterolemia in childhood and adolescence: a review

The Effect of Mipomersen in the Management of Patients with Familial Hypercholesterolemia: A Systematic Review and Meta-Analysis of Clinical Trials

Background: Familial hypercholesterolemia (FH) lead to significant adverse effects in coronary arteries. Mipomersen is a second-generation antisense oligonucleotide that inhibits the synthesis of apolipoprotein B-100, an essential component of low density lipoprotein (LDL), and thus decreases the production of LDL. We aimed to determine the effect of mipomersen in patients with FH. Methods: We searched Ovid Medline, Ovid EMBASE, WHO ICTRP search portal, ISI database, the reference lists of relevant articles, and also Google Scholar to retrieve articles. All randomized controlled trials (RCTs) comparing patients with FH receiving mipomersen as an add-on and a parallel group receiving a placebo or no intervention were selected. Results: Five studies with more than 500 patients were included. All had low risk of bias. Pooling data showed that mipomersen probably reduces LDL compared with placebo [mean difference: −24.79, 95% CI (−30.15, −19.43)] but with a moderate level of certainty. There was a high level of evidence for injection site reactions [RR = 2.56, CI (1.47–4.44)] and a low level for increased serum alanine transaminase (ALT) > 3 times upper limit of normal (ULN) [RR = 5.19, CI (1.01–26.69)]. Conclusion: A moderate level of evidence in decreasing serum LDL indicates that we are uncertain if this drug provides benefit in any outcome important to patients. Although a low level of evidence for an increase in serum ALT leaves uncertainty about this adverse effect, injection site reactions in 10% or more of patients can be an important concern.

Promoting cardiovascular health post-transplant through early diagnosis and adequate management of hypertension and dyslipidemia

Despite correction of underlying solid organ failure by transplantation, pediatric transplant recipients still have increased mortality rates compared to the general pediatric population, in part due to increased cardiovascular risk. In particular, pediatric kidney and non-kidney transplant recipients with chronic kidney disease have significant cardiovascular risk that worsens with declining kidney function. Biomarkers associated with future cardiovascular risk such as casual and ambulatory hypertension, dyslipidemia, vascular stiffness and calcification, and left ventricular hypertrophy can be detected throughout the post-transplant period and in patients with stable kidney function. Among these, hypertension and dyslipidemia are two potentially modifiable cardiovascular risk factors that are highly prevalent in kidney and non-kidney pediatric transplant recipients. Standardized approaches to appropriate BP measurement and lipid monitoring are needed to detect and address these risk factors in a timely fashion. To achieve sustained improvement in cardiovascular health, clinicians should partner with patients and their caregivers to address these and other risk factors with a combined approach that integrates pharmacologic with non-pharmacologic approaches. This review outlines the scope and impact of hypertension and dyslipidemia in pediatric transplant recipients, with a particular focus on pediatric kidney transplantation given the high burden of chronic kidney disease-associated cardiovascular risk. We also review the current published guidelines for monitoring and managing abnormalities in blood pressure and lipids, highlighting the important role of therapeutic lifestyle changes in concert with antihypertensive and lipid-lowering medications.

Efficacy of therapeutic lifestyle changes on lipid profiles assessed by NMR in children with familial and non-familial hypercholesterolemia

BACKGROUND AND AIMS

The first line of therapy in children with hypercholesterolaemia is therapeutic lifestyle changes (TLSC). The efficacy of lifestyle intervention in children with familial hypercholesterolaemia (FH), where LDL-C levels are genetically driven, deserves a focused study.

AIMS

To evaluate the impact of a lifestyle education program, focused on food patterns and physical activity, on lipid profiles assessed by nuclear magnetic resonance (NMR) in children with FH vs. non-FH.

METHODS

Phase 1 was a cross-sectional study of baseline characteristics, and phase 2 was a prospective TLSC intervention study. In total, the study included 238 children (4 to 18 years old; 47% girls) attending the lipid unit of our hospital due to high cholesterol levels. Eighty-five were diagnosed with FH (72% genetic positive), and 153 were diagnosed with non-Familial hypercholesterolaemia. A quantitative food frequency questionnaire (FFQ) including 137 items was used. Physical activity (PA) was assessed by the Minnesota questionnaire. The lipid profile was assessed using the 2D-1H-NMR (Liposcale test). A total of 127 children (81 in the FH group) participated in the prospective phase and were re-assessed after 1 year of the TLSC intervention, consisting of education on lifestyle changes delivered by a specialized nutritionist.

RESULTS

The FH and non-FH groups were similar in anthropometry and clinical data, except that those in the FH were slightly younger than those in the non-FH group. Both the FH and non-FH groups showed a similar diet composition characterized by a high absolute calorie intake and a high percentage of fat, mainly saturated fat. The PA was below the recommended level in both groups. After one year of TLSC, the percentage of total and saturated fats was reduced, and the amount of fiber increased significantly in both groups. The percentage of protein increased slightly. The number of children engaged in at least 1 hour/day of PA increased by 56% in the FH group and by 53% in the non-FH group, and both these increases were significant. The total and small-LDL particle numbers were reduced in both groups, although the absolute change was greater in the FH group than in the non-FH group.

CONCLUSIONS

Educational strategies to implement TLSC in children lead to empowerment, increased adherence, and overall metabolic improvement in children with high blood cholesterol, including those with FH.

Molecular aspects of hypercholesterolemia treatment: current perspectives and hopes

Hypercholesterolemia is a pathological condition which has been reported in 39% of the worlds' adult population. We aimed to review molecular aspects of current and novel therapeutic approaches based on low-density lipoprotein cholesterol lowering strategies. Pathogenic mutations in the LDLR, ApoB, PCSK9 and LDLRAP genes cause deficient clearance of circulating low-density lipoprotein cholesterol particles via hepatic LDL receptor. This leads to increased plasma LDL cholesterol levels from birth, which can cause LDL depositions in the arterial walls. Ultimately, it progresses to atherosclerosis and an increased risk of premature cardiovascular diseases. Currently, statins, Ezetimibe, Bile acid sequestrants and PCSK9 inhibitors are the main therapeutic agents for the treatment of hypercholesterolemia. Moreover, novel RNA-based therapy had a strong impact on therapeutic strategies in recent decades. Additional development in understanding of the molecular basis of hypercholesterolemia will provide opportunities for the development of targeted therapy in the near future. Key Messages The most common genes involved in hypercholesterolemia are LDLR, PCSK9 and ApoB. Pharmacogenetic effects are typically constrained to pathways closely related to the pharmacodynamics and pharmacokinetics. Change in lifestyle and diet along with treatment of the underlying disease and drug therapy are the current therapeutic strategies.

Treatment of familial hypercholesterolaemia in children and adolescents in the last three decades

BACKGROUND

This study evaluated the effectiveness of long-term intensive lipid-lowering therapy in children and adolescents with familial hypercholesterolaemia.

METHODS

The charts of 89 children and adolescents with heterozygous familial hypercholesterolaemia among ∼1000 patients treated from 1974 to 2008 were reviewed. Familial hypercholesterolaemia was defined as low-density lipoprotein cholesterol level >90th percentile in individuals with a history of familial hypercholesterolaemia.

RESULTS

Of the 89 patients, 51% were male; the mean age at diagnosis was 8 ± 4 years, and the mean follow-up was 13 ± 8 years. Baseline and most recent low-density lipoprotein cholesterol levels (mg/dl) under treatment were 250 ± 50 and 142 ± 49, respectively, reduced 43% from baseline (p < 0.0001). At the most recent visit, 39 patients received statin monotherapy, mainly atorvastatin or rosuvastatin, and 50 (56%) patients received combination therapy, mainly vytorin or rosuvastain/ezetimibe, 15 patients were >30 years of age, and none developed symptomatic cardiovascular disease or needed revascularisation.

CONCLUSIONS

Long-term statin-based therapy can reduce low-density lipoprotein cholesterol levels in most children and adolescents with heterozygous familial hypercholesterolaemia and decrease cardiovascular risk significantly.

Management of familial hypercholesterolemia in children and young adults: consensus paper developed by a panel of lipidologists, cardiologists, paediatricians, nutritionists, gastroenterologists, general practitioners and a patient organization

Since heterozygous familial hypercholesterolemia (HeFH) is a disease that exposes the individual from birth onwards to severe hypercholesterolemia with the development of early cardiovascular disease, a clear consensus on the management of this disease in young patients is necessary. In Belgium, a panel of paediatricians, specialists in (adult) lipid management, general practitioners and representatives of the FH patient organization agreed on the following common recommendations. 1. Screening for HeFH should be performed only in children older than 2 years when HeFH has been identified or is suspected (based on a genetic test or clinical criteria) in one parent.2. The diagnostic procedure includes, as a first step, the establishment of a clear diagnosis of HeFH in one of the parents. If this precondition is satisfied, a low-density-lipoprotein cholesterol (LDL-C) levelabove 3.5 mmol/L (135 mg/dL) in the suspected child is predictive for differentiating affected from non-affected children. 3. A low saturated fat and low cholesterol diet should be started after 2 years, under the supervision of a dietician or nutritionist.4. The pharmacological treatment, using statins as first line drugs, should usually be started after 10 years if LDL-C levels remain above 5 mmol/L (190 mg/dL), or above 4 mmol/L (160 mg/dL) in the presence of a causative mutation, a family history of early cardiovascular disease or severe risk factors. The objective is to reduce LDL-C by at least 30% between 10 and 14 years and, thereafter, to reach LDL-C levels of less than 3.4 mmol/L (130 mg/dL).

CONCLUSION

The aim of this consensus statement is to achieve more consistent management in the identification and treatment of children with HeFH in Belgium.

A systematic review of bile acid sequestrant therapy in children with familial hypercholesterolemia

Familial hypercholesterolemia, which arises as a result of a mutation in the low-density lipoprotein (LDL) receptor gene, is characterized by elevated levels of low-density lipoprotein cholesterol (LDL-C), regardless of dietary and lifestyle modifications. Pharmacological therapy is often required to adequately control the elevated LDL-C levels associated with familial hypercholesterolemia. However, children with this genetic condition present many challenges for physicians, who must weigh the benefits of lipid-lowering therapy against the risks associated with the various treatment options. Furthermore, because familial hypercholesterolemia is a chronic condition, children will likely require long-term lipid-lowering therapy. As such, the potential effect of pharmacological treatment on development is of paramount importance in this population. Bile acid sequestrants represent a unique treatment option for children with familial hypercholesterolemia in that these agents are not systemically absorbed but rather exert their lipid-lowering effects via binding to bile acids within the gastrointestinal tract. A literature search was performed to identify clinical data related to the use of bile acid sequestrant therapy in children (< 18 years of age) with familial hypercholesterolemia. Studies published in English between 1990 and December 2010 that were retrieved from MEDLINE and EMBASE were included in this systematic review. In total, five clinical studies were identified that evaluated bile acid sequestrant monotherapy, whereas two studies were identified that evaluated combination therapy with a bile acid sequestrant and low-dose statin. This review summarizes the clinical data regarding the efficacy and safety of bile acid sequestrants in this specialized population.

Optimal management of familial hypercholesterolemia: treatment and management strategies

Familial hypercholesterolemia is an autosomally dominant disorder caused by various mutations in low-density lipoprotein receptor genes. This will lead to elevated levels of total and low-density lipoprotein cholesterol, which may in turn lead to premature coronary atherosclerosis and cardiac-related death. The symptoms are more severe in the homozygous type of the disease. Different options for the treatment of affected patients are now available. Diet therapy, pharmacologic therapy, lipid apheresis, and liver transplantation are among the various treatments. We clinically review the treatment and management strategies for the disease in order to shed light on the optimal management of familial hypercholesterolemia.

Evaluation and management of hyperlipidemia in children and adolescents

PURPOSE OF REVIEW

To review the recent findings on evaluation and management of dyslipidemia in childhood and adolescence, giving a critical view on new therapeutic approaches.

RECENT FINDINGS

In 2008, the American Academy of Pediatrics released an updated policy statement recommending more frequent screening to detect dyslipidemia in childhood and the first-line use of statins in children with dyslipidemia who did not respond to lifestyle intervention and who were more than 8 years of age. These recommendations have caused a lot of controversy within the medical community and media. This debate is also sharpened by the fact that only few trials have investigated the long-term efficacy of statins on prevention of adult cardiovascular disease, their application in dyslipidemias other than familial hypercholesterolemia and the use of new pharmacological tools.

SUMMARY

The purpose of our paper could not be achieved clearly without a review of the physiology of cholesterol metabolism together with an analysis of causes of primary and secondary dyslipidemia affecting children. Moreover, recent knowledge on lipid-lowering therapy is reviewed.

Coronary insufficiency in children: Review of literature and report of a rare case with unknown aetiology

Myocardial ischemia due to coronary artery disease is a rare condition in children. The reported causes of this condition include vasculitis; commonest being Kawasaki' disease, pre-mature atherosclerosis due to familial dyslipidemias, congenital coronary artery anomalies and post-operative complications of procedures requiring coronary artery re-implantation in children, e.g. arterial switch procedure and Ross procedure. Allograft arteriopathy after heart transplantation is a more recent addition to this list (Mavroudis et al., 1996). Surgical procedures required for the treatment of coronary artery disease in children include, but are not limited to coronary artery re-implantation, re-routing, augmentation of the osteum, and coronary artery bypass grafting (CABG). We present our experience of a rare case of triple vessel coronary artery disease of unknown aetiology in a child, treated with coronary artery bypass grafting procedure.

Reduced pain and inflammation in juvenile and adult rats fed a ketogenic diet

The ketogenic diet is a high-fat, low-carbohydrate regimen that forces ketone-based rather than glucose-based cellular metabolism. Clinically, maintenance on a ketogenic diet has been proven effective in treating pediatric epilepsy and type II diabetes, and recent basic research provides evidence that ketogenic strategies offer promise in reducing brain injury. Cellular mechanisms hypothesized to be mobilized by ketone metabolism and underlying the success of ketogenic diet therapy, such as reduced reactive oxygen species and increased central adenosine, suggest that the ketolytic metabolism induced by the diet could reduce pain and inflammation. To test the effects of a ketone-based metabolism on pain and inflammation directly, we fed juvenile and adult rats a control diet (standard rodent chow) or ketogenic diet (79% fat) ad libitum for 3-4 weeks. We then quantified hindpaw thermal nociception as a pain measure and complete Freund's adjuvant-induced local hindpaw swelling and plasma extravasation (fluid movement from the vasculature) as inflammation measures. Independent of age, maintenance on a ketogenic diet reduced the peripheral inflammatory response significantly as measured by paw swelling and plasma extravasation. The ketogenic diet also induced significant thermal hypoalgesia independent of age, shown by increased hindpaw withdrawal latency in the hotplate nociception test. Anti-inflammatory and hypoalgesic diet effects were generally more robust in juveniles. The ketogenic diet elevated plasma ketones similarly in both age groups, but caused slowed body growth only in juveniles. These data suggest that applying a ketogenic diet or exploiting cellular mechanisms associated with ketone-based metabolism offers new therapeutic opportunities for controlling pain and peripheral inflammation, and that such a metabolic strategy may offer significant benefits for children and adults.