title: Infant BMI or Weight-for-Length and Obesity Risk in Early Childhood.
abstract: Weight-for-length (WFL) is currently used to assess adiposity under 2 years. We assessed WFL- versus BMI-based estimates of adiposity in healthy infants in determining risk for early obesity.
  
  
  
  Anthropometrics were extracted from electronic medical records for well-child visits for 73 949 full-term infants from a large pediatric network. World Health Organization WFL and BMI z scores (WFL-z and BMI-z, respectively) were calculated up to age 24 months. Correlation analyses assessed the agreement between WFL-z and BMI-z and within-subject tracking over time. Logistic regression determined odds of obesity at 2 years on the basis of adiposity classification at 2 months.
  
  
  
  Agreement between WFL-z and BMI-z increased from birth to 6 months and remained high thereafter. BMI-z at 2 months was more consistent with measurements at older ages than WFL-z at 2 months. Infants with high BMI (≥85th percentile) and reference WFL (5th-85th percentiles) at 2 months had greater odds of obesity at 2 years than those with high WFL (≥85th percentile) and reference BMI (5th-85th percentiles; odds ratio, 5.49 vs 1.40; P < .001). At 2 months, BMI had a higher positive predictive value than WFL for obesity at 2 years using cut-points of either the 85th percentile (31% vs 23%) or 97.7th percentile (47% vs 29%).
  
  
  
  High BMI in early infancy is more strongly associated with early childhood obesity than high WFL. Forty-seven percent of infants with BMI ≥97.7th percentile at 2 months (versus 29% of infants with WFL ≥97.7th percentile at 2 months) were obese at 2 years. Epidemiologic studies focused on assessing childhood obesity risk should consider using BMI in early infancy.
authors.affiliation: Divisions of Endocrinology and Diabetes.
authors.forename: Sani M
authors.initials: SM
authors.lastname: Roy
authors.affiliation: Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and.
authors.forename: Jordan G
authors.initials: JG
authors.lastname: Spivack
authors.affiliation: Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Myles S
authors.initials: MS
authors.lastname: Faith
authors.affiliation: Human Genetics, and.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Chesi
authors.affiliation: Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania;
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Mitchell
authors.affiliation: Divisions of Endocrinology and Diabetes, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kelly
authors.affiliation: Divisions of Endocrinology and Diabetes, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and Human Genetics, and.
authors.forename: Struan F A
authors.initials: SF
authors.lastname: Grant
authors.affiliation: Divisions of Endocrinology and Diabetes, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; and.
authors.forename: Shana E
authors.initials: SE
authors.lastname: McCormack
authors.affiliation: Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; zemel@email.chop.edu.
authors.forename: Babette S
authors.initials: BS
authors.lastname: Zemel
mesh_terms: D050154:Adiposity; D015992:Body Mass Index; D001837:Body Weights and Measures / Q000379:methods*; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D063766:Pediatric Obesity / Q000453:epidemiology*; D011237:Predictive Value of Tests; D012307:Risk Factors