title: Prevalence of high HbA1c levels in Brazilian adolescents: The Study of Cardiovascular Risk in Adolescents.
abstract: OBJECTIVE
  To evaluate the prevalence of elevated glycated haemoglobin (HbA1c) levels in a population of adolescents participating in the Study of Cardiovascular Risk in Adolescents.
  
  
  METHODS
  This is a school-based cross-sectional study based on a complex sample of adolescents 12-17years old representative at the national and macro-regional levels and for each Brazilian state capital. Blood was collected in schools and then evaluated in a single laboratory. HbA1c levels were considered elevated if ⩾5.7% (39mmol/mol) and were analyzed according to sex, age, macro-region, type of school, skin color, and nutritional status.
  
  
  RESULTS
  Data from 37,804 adolescents were analyzed. The mean level of HbA1c was 5.4% (95%CI 5.4-5.4) (36mmol/mol [95%CI 36-36]), and 20.5% (95%CI 19.1-22.0) of adolescents presented values ⩾5.7% (⩾39mmol/mol). Among males, 23.6% (95%CI 21.8-25.6) showed elevated HbA1c levels compared to 17.5% (95%CI 15.9-19.2) observed in females. The prevalence of elevated levels of HbA1c was higher in adolescents with black skin color (27.6%; 95%CI 23.2-32.4) vs. white skin color (16.9%; 95%CI 15.4-18.5), and higher in those who studied in public schools (21.6%; 95%CI 20.0-23.4) vs. private schools (16.7%; 95%CI 14.7-19.0). Among obese adolescents, 29.7% (95%CI 25.4-34.3) had elevated levels of HbA1c, compared to 19.3% (95%CI 18.0-20.7) in normal weight students and 19.7% (95%CI 17.1-22.6) in overweight adolescents.
  
  
  CONCLUSIONS
  Obese male adolescents of lower socioeconomic status had a higher prevalence of elevated HbA1c levels. Our findings highlight the importance of focusing on this high risk group for interventions to prevent diabetes.
authors.affiliation: Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Rita
authors.initials: R
authors.lastname: de Cássia Lima Fernandes
authors.affiliation: Post-graduate Program in Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Gabriela H
authors.initials: GH
authors.lastname: Teló
authors.affiliation: Post-graduate Program in Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Felipe V
authors.initials: FV
authors.lastname: Cureau
authors.affiliation: Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasília, DF, Brazil.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Barufaldi
authors.affiliation: Núcleo de Estudos da Saúde do Adolescente, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Maria Cristina C
authors.initials: MC
authors.lastname: Kuschnir
authors.affiliation: Post-graduate Program in Endocrinology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Endocrinology Department, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Beatriz D
authors.initials: BD
authors.lastname: Schaan
authors.affiliation: Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Moyses
authors.initials: M
authors.lastname: Szklo
authors.affiliation: Instituto de Estudos em Saúde Coletiva, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. Electronic address: kbloch@iesc.ufrj.br.
authors.forename: Katia V
authors.initials: KV
authors.lastname: Bloch
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002648:Child; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors
chemical_list: D006442:Glycated Hemoglobin
keywords: Adolescent; Developing countries; Diabetes mellitus; Hemoglobin A, glycosylated; Obesity