The Study of Cardiovascular Risk in Adolescents--ERICA: rationale, design and sample characteristics of a national survey examining cardiovascular risk factor profile in Brazilian adolescents.

BACKGROUND: The Study of Cardiovascular Risk in Adolescents (Portuguese acronym, "ERICA") is a multicenter, school-based country-wide cross-sectional study funded by the Brazilian Ministry of Health, which aims at estimating the prevalence of cardiovascular risk factors, including those included in the definition of the metabolic syndrome, in a random sample of adolescents aged 12 to 17 years in Brazilian cities with more than 100,000 inhabitants. Approximately 85,000 students were assessed in public and private schools. Brazil is a continental country with a heterogeneous population of 190 million living in its five main geographic regions (North, Northeast, Midwest, South and Southeast). ERICA is a pioneering study that will assess the prevalence rates of cardiovascular risk factors in Brazilian adolescents using a sample with national and regional representativeness. This paper describes the rationale, design and procedures of ERICA. METHODS/DESIGN: Participants answered a self-administered questionnaire using an electronic device, in order to obtain information on demographic and lifestyle characteristics, including physical activity, smoking, alcohol intake, sleeping hours, common mental disorders and reproductive and oral health. Dietary intake was assessed using a 24-hour dietary recall. Anthropometric measures (weight, height and waist circumference) and blood pressure were also be measured. Blood was collected from a subsample of approximately 44,000 adolescents for measurements of fasting glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, glycated hemoglobin and fasting insulin. DISCUSSION: The study findings will be instrumental to the development of public policies aiming at the prevention of obesity, atherosclerotic diseases and diabetes in an adolescent population.

Association between anthropometric measures and insulin resistance in Brazilian adolescents: data from the national study of cardiovascular risk factors in adolescents - ERICA.

OBJECTIVES: To evaluate anthropometric measures (AM) and insulin resistance (IR) association in adolescents aged 12-17 years and investigates how body mass index (BMI) interrelates with specific indicators of fat distribution in this association. METHODS: This analysis is from the Study of Cardiovascular Risks in Adolescents (ERICA) study, a national, cross-sectional study. AM was categorized by quartiles, and their means and 95% confidence intervals (95% CI) were estimated. The prevalence of IR was estimated for each AM according to the quartiles. The associations between AM and homeostatic model assessment of insulin resistance (HOMA-IR) levels were analyzed using Poisson models. RESULTS: 37,892 adolescents were included. IR prevalence tended to increase as quartiles increased for each AM. The association of BMI with IR persisted with the adjustment for others AM. The greatest reduction in the association's strength was achieved with the adjustment by the waist circumference (WC) and the waist-to-height ratio (WHtR). Most other AM were also associated with IR. CONCLUSION: AM has a positive association with the prevalence of IR, and the joint effect of BMI and central adiposity measures should be considered in cardiometabolic risk evaluation in adolescents.