Prevalence of high cholesterol levels suggestive of familial hypercholesterolemia in Brazilian adolescents: Data from the study of cardiovascular risk in adolescents

Consensus document on diagnosis and management of familial hypercholesterolemia from the Italian Society for the Study of Atherosclerosis (SISA)

AIMS

Familial Hypercholesterolemia (FH) is a genetic disorder of lipoprotein metabolism that causes an increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Although early diagnosis and treatment of FH can significantly improve the cardiovascular prognosis, this disorder is underdiagnosed and undertreated. For these reasons the Italian Society for the Study of Atherosclerosis (SISA) assembled a Consensus Panel with the task to provide guidelines for FH diagnosis and treatment.

DATA SYNTHESIS

Our guidelines include: i) an overview of the genetic complexity of FH and the role of candidate genes involved in LDL metabolism; ii) the prevalence of FH in the population; iii) the clinical criteria adopted for the diagnosis of FH; iv) the screening for ASCVD and the role of cardiovascular imaging techniques; v) the role of molecular diagnosis in establishing the genetic bases of the disorder; vi) the current therapeutic options in both heterozygous and homozygous FH. Treatment strategies and targets are currently based on low-density lipoprotein cholesterol (LDL-C) levels, as the prognosis of FH largely depends on the magnitude of LDL-C reduction achieved by lipid-lowering therapies. Statins with or without ezetimibe are the mainstay of treatment. Addition of novel medications like PCSK9 inhibitors, ANGPTL3 inhibitors or lomitapide in homozygous FH results in a further reduction of LDL-C levels. LDL apheresis is indicated in FH patients with inadequate response to cholesterol-lowering therapies.

CONCLUSION

FH is a common, treatable genetic disorder and, although our understanding of this disease has improved, many challenges still remain with regard to its identification and management.

Differences in pediatric cholesterol screening rates between family physicians and pediatricians correlate with conflicting guidelines

Conflicting guidelines regarding universal pediatric cholesterol screening were released between 2011 and 2019, but the impact on screening rates remains understudied. The purpose of this study was to examine trends in pediatric cholesterol screening rates within a single institution in the United States and their association with release of national guidelines, local educational tools, and electronic health record (EHR) modifications. Order placement was defined as ordering a high-density lipoprotein cholesterol level in a patient aged 9-21 years with ≥1 well visit in prior 3 years. Order placement rate (OPR) was calculated per month using 3 months' moving average smoothing and analyzed based on date, patient age, and specialty of ordering clinician. Timing of educational tools, EHR modifications, and national guideline release were analyzed for changes in OPR. Prior to release of 2011 guidelines recommending universal pediatric cholesterol screening, pediatrician OPR was 35% (95% CI: 29-43%) compared to 8% (7-11%) for family physicians. For both specialties, OPR increased after 2011 guidelines, educational initiatives, and EHR changes, but decreased after 2016, with a larger decrease for family physicians (p < 0.001 for all). OPR was consistently higher for pediatricians than for family physicians during the study period, with largest OPR changes correlating with release of guidelines. The findings from the study suggest that conflicting guidelines may contribute to lower overall OPR, and to different screening rates for children cared for by pediatricians compared to family physicians.

Cascade Screening and Treatment Initiation in Young Adults with Heterozygous Familial Hypercholesterolemia

Heterozygous familial hypercholesterolemia (HeFH) creates elevated low-density lipoprotein cholesterol (LDL-C), causing premature atherosclerotic cardiovascular disease (ASCVD). Guidelines recommend cascade screening relatives and starting statin therapy at 8–10 years old, but adherence to these recommendations is low. Our purpose was to measure self-reported physician practices for cascade screening and treatment initiation for HeFH using a survey of 500 primary care physicians and 500 cardiologists: 54% “always” cascade screen relatives of an individual with FH, but 68% would screen individuals with “strong family history of high cholesterol or premature ASCVD”, and 74% would screen a child of a patient with HeFH. The most likely age respondents would start statins was 18–29 years, with few willing to prescribe to a pediatric male (17%) or female (14%). Physicians who reported previously diagnosing a patient with HeFH were more likely to prescribe to a pediatric patient with HeFH, either male (OR = 1.34, 95% CI = 0.99–1.81) or female (OR = 1.31, 95% CI = 0.99–1.72). Many physicians do not cascade screen and are less likely to screen individuals with family history of known HeFH compared to “high cholesterol or premature ASCVD”. Most expressed willingness to screen pediatric patients, but few would start treatment at recommended ages. Further education is needed to improve diagnosis and treatment of HeFH.

Prevalence of Familial Hypercholesterolemia Among the General Population and Patients With Atherosclerotic Cardiovascular Disease

Background:

Contemporary studies suggest that familial hypercholesterolemia (FH) is more frequent than previously reported and increasingly recognized as affecting individuals of all ethnicities and across many regions of the world. Precise estimation of its global prevalence and prevalence across World Health Organization regions is needed to inform policies aiming at early detection and atherosclerotic cardiovascular disease (ASCVD) prevention. The present study aims to provide a comprehensive assessment and more reliable estimation of the prevalence of FH than hitherto possible in the general population (GP) and among patients with ASCVD.

Methods:

We performed a systematic review and meta-analysis including studies reporting on the prevalence of heterozygous FH in the GP or among those with ASCVD. Studies reporting gene founder effects and focused on homozygous FH were excluded. The search was conducted through Medline, Embase, Cochrane, and Global Health, without time or language restrictions. A random-effects model was applied to estimate the overall pooled prevalence of FH in the general and ASCVD populations separately and by World Health Organization regions.

Results:

From 3225 articles, 42 studies from the GP and 20 from populations with ASCVD were eligible, reporting on 7 297 363 individuals/24 636 cases of FH and 48 158 patients/2827 cases of FH, respectively. More than 60% of the studies were from Europe. Use of the Dutch Lipid Clinic Network criteria was the commonest diagnostic method. Within the GP, the overall pooled prevalence of FH was 1:311 (95% CI, 1:250–1:397; similar between children [1:364] and adults [1:303], P =0.60; across World Health Organization regions where data were available, P =0.29; and between population-based and electronic health records–based studies, P =0.82). Studies with ≤10 000 participants reported a higher prevalence (1:200–289) compared with larger cohorts (1:365–407; P <0.001). The pooled prevalence among those with ASCVD was 18-fold higher than in the GP (1:17 [95% CI, 1:12–1:24]), driven mainly by coronary artery disease (1:16; [95% CI, 1:12–1:23]). Between-study heterogeneity was large ( I 2 >95%). Tests assessing bias were nonsignificant ( P >0.3).

Conclusions:

With an overall prevalence of 1:311, FH is among the commonest genetic disorders in the GP, similarly present across different regions of the world, and is more frequent among those with ASCVD. The present results support the advocacy for the institution of public health policies, including screening programs, to identify FH early and to prevent its global burden.

Prevalence of Combined Lipid Abnormalities in Brazilian Adolescents and Its Association with Nutritional Status: Data from the Erica Study

Background:

Cardiovascular diseases are the leading cause of death in Brazil and worldwide. The growing incidence of obesity in children and adolescents and its association with lipid abnormalities may worsen this scenario, mainly in developing countries where obesity has reached epidemic levels. Dyslipidemias have several patterns, and the combination of some lipid abnormalities may have higher atherogenic potential.

Objectives:

To evaluate the prevalence of single or multiple combined lipid abnormalities in adolescents and its association with nutritional status assessed by body mass index.

Methods:

Data were obtained from the Study of Cardiovascular Risks in Adolescents (ERICA), a school-based, national representative study with Brazilian adolescents between 12 and 17 years of age. Adolescents whose lipid profiles were available were included, and lipid abnormalities were defined as LDL-C ≥ 100 mg/dL, HDL-C < 45 mg/dL, and tryglicerides (TG) ≥ 100 mg/dL. We assessed the prevalence of single or combined lipid abnormalities and correlated this nutritional status with body mass index of low weight, normal, overweight, and obesity.

Results:

A total of 38,069 adolescents were included, with more than 24,000 of them presenting at least one lipid abnormality (64.7%), and 3.7% showing alterations in all of them. The most prevalent combination was high TG with low HDL-C levels. The higher the BMI, the more lipid abnormalities were found.

Conclusions:

In this large and representative sample of Brazilian adolescents, the majority had at least one lipid abnormality. Higher BMI was associated with a higher prevalence of combined lipid abnormalities.

Highlights: