title: Cardiometabolic risk assessments by body mass index z-score or waist-to-height ratio in a multiethnic sample of sixth-graders.
abstract: Convention defines pediatric adiposity by the body mass index z-score (BMIz) referenced to normative growth charts. Waist-to-height ratio (WHtR) does not depend on sex-and-age references. In the HEALTHY Study enrollment sample, we compared BMIz with WHtR for ability to identify adverse cardiometabolic risk. Among 5,482 sixth-grade students from 42 middle schools, we estimated explanatory variations (R (2)) and standardized beta coefficients of BMIz or WHtR for cardiometabolic risk factors: insulin resistance (HOMA-IR), lipids, blood pressures, and glucose. For each risk outcome variable, we prepared adjusted regression models for four subpopulations stratified by sex and high versus lower fatness. For HOMA-IR, R (2) attributed to BMIz or WHtR was 19%-28% among high-fatness and 8%-13% among lower-fatness students. R (2) for lipid variables was 4%-9% among high-fatness and 2%-7% among lower-fatness students. In the lower-fatness subpopulations, the standardized coefficients for total cholesterol/HDL cholesterol and triglycerides tended to be weaker for BMIz (0.13-0.20) than for WHtR (0.17-0.28). Among high-fatness students, BMIz and WHtR correlated with blood pressures for Hispanics and whites, but not black boys (systolic) or girls (systolic and diastolic). In 11-12 year olds, assessments by WHtR can provide cardiometabolic risk estimates similar to conventional BMIz without requiring reference to a normative growth chart.
authors.affiliation: Division of Diabetes Translation, Centers for Disease Control & Prevention, CDC Mail Stop F-73, 4770 Buford Highway, Atlanta, GA 30341, USA.
authors.forename: Henry S
authors.initials: HS
authors.lastname: Kahn
authors.affiliation: The Biostatistics Center, George Washington University, Rockville, MD 20852, USA.
authors.forename: Laure
authors.initials: L
authors.lastname: El ghormli
authors.affiliation: School for Policy Studies, University of Bristol, Bristol BS8 1TZ, UK.
authors.forename: Russell
authors.initials: R
authors.lastname: Jago
authors.affiliation: Center for Obesity Research and Education, Temple University, Philadelphia, PA 19122, USA.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Foster
authors.affiliation: Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Robert G
authors.initials: RG
authors.lastname: McMurray
authors.affiliation: Division of Endocrinology, Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: John B
authors.initials: JB
authors.lastname: Buse
authors.affiliation: Division of Health Promotion & Sports Medicine, Oregon Health & Science University, Portland, OR 97239, USA.
authors.forename: Diane D
authors.initials: DD
authors.lastname: Stadler
authors.affiliation: Social & Health Research Center, San Antonio, TX 78210, USA.
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Treviño
authors.affiliation: Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Baranowski
authors.affiliation: The Biostatistics Center, George Washington University, Rockville, MD 20852, USA.
mesh_terms: D050154:Adiposity; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000208:ethnology / Q000517:prevention & control*; D002648:Child; D002652:Child Behavior; D008076:Cholesterol, HDL / Q000097:blood; D005260:Female; D006266:Health Education; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008297:Male; D063766:Pediatric Obesity / Q000208:ethnology / Q000517:prevention & control* / Q000523:psychology; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors; D013334:Students / Q000523:psychology; D014280:Triglycerides / Q000097:blood; D014481:United States / Q000453:epidemiology; D065927:Waist-Height Ratio
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008055:Lipids; D014280:Triglycerides