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

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder with an estimated worldwide prevalence ranging from 1 in 200 individuals to 1 in 500 individuals in its heterozygous form. Individuals with FH exhibit high low-density lipoprotein cholesterol (LDLc) levels from birth, which leads to premature cardiovascular events. In Brazil, like in most countries around the world, FH is considered a public health problem but remains underdiagnosed and undertreated.

OBJECTIVE

The aim of this study was to evaluate the prevalence of LDLc or non-high-density lipoprotein cholesterol (non-HDLc) levels suggestive of FH among Brazilian adolescents.

METHODS

The Study of Cardiovascular Risk in Adolescents (ERICA) was a nationwide, school-based, cross-sectional study that assessed the prevalence of cardiovascular risk factors in approximately 75,000 adolescents between 12 and 17 years old. Data were analyzed according to sex, age, type of school (public or private), and geographic regions of Brazil. Adolescents with untreated fasting LDLc levels of 160 mg/dL or higher or non-HDLc levels of 190 mg/dL or higher were suspected to have FH. We also evaluated the prevalence of LDLc levels of 190 mg/dL or higher, which is highly suggestive of a diagnosis of FH in this age group.

RESULTS

A total of 38,069 adolescents were evaluated; more than half (59.9%) were female and most (74%) attended public schools. The prevalence of LDLc levels of 160 mg/dL or higher or non-HDLc levels of 190 mg/dL or higher among the adolescents was 0.49% (95% confidence interval: 0.34-0.71; n = 209). Moreover, 0.12% of the adolescents (95% confidence interval: 0.04-0.34; n = 44) had LDLc levels of 190 mg/dL or higher. We estimate that approximately 100,000 (1 in 200) Brazilian adolescents aged 12 to 17 years are suspected to have FH on the basis of LDLc and non-HDLc levels.

CONCLUSION

We identified a significant prevalence of cholesterol levels suggestive of FH among Brazilian adolescents. Further evaluation is needed to confirm the diagnoses among the students. Our results reinforce the importance of universal screening as a critical tool for early diagnosis and treatment of FH.