title: Age, sex, and ethnic variations in serum insulin concentrations among U.S. youth: findings from the National Health and Nutrition Examination Survey 1999-2002.
abstract: OBJECTIVE
  Distributions of serum concentrations of insulin among adolescents and young adults are poorly understood in the U.S. The objective of this study was to describe the distribution of serum insulin across demographic characteristics of U.S. adolescents and young adults.
  
  
  METHODS
  A total of 1,791 male and female subjects aged 12-19 years who participated in the National Health and Nutrition Examination Surveys for 1999-2002 were included in the analyses.
  
  
  RESULTS
  Among male participants, serum concentrations of insulin increased from age 12 to 14 years before decreasing. Among female participants, concentrations were highest at age 13 years before decreasing steadily through age 19 years. Among participants aged 12-17 years but not those aged 18-19 years, females had higher mean log-transformed concentrations than males (P, Wald, F = 0.038 and 0.125, respectively) after adjusting for age and ethnicity. After adjusting for age and BMI percentile, mean log-transformed concentrations were higher in African-American females aged 12-17 years than in white or Mexican-American participants. No significant ethnic differences were found among female participants aged 18-19 years or male participants aged 12-19 years. Concentrations of insulin increased strongly with increasing levels of BMI.
  
  
  CONCLUSIONS
  These results provide detailed information about serum concentrations of insulin in a representative sample of U.S. adolescents and young adults and may be useful to monitor future trends of this risk factor for diabetes and cardiovascular disease.
authors.affiliation: Division of Adult and Community Health, Centers for Disease Control Prevention, 4770 Buford Hwy., MS K66, Atlanta, GA 30341, USA. eford@cdc.gov
authors.forename: Earl S
authors.initials: ES
authors.lastname: Ford
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Li
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Imperatore
authors.forename: Stephen
authors.initials: S
authors.lastname: Cook
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D005006:Ethnicity; D005260:Female; D006306:Health Surveys; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D009752:Nutritional Status; D044469:Racial Groups; D012727:Sex Characteristics; D014481:United States
chemical_list: D007328:Insulin