Kahn Henry S, El ghormli Laure, Jago Russell, Foster Gary D, McMurray Robert G, Buse John B, Stadler Diane D, Treviño Roberto P, Baranowski Tom
Division of Diabetes Translation, Centers for Disease Control & Prevention, CDC Mail Stop F-73, 4770 Buford Highway, Atlanta, GA 30341, USA.
The Biostatistics Center, George Washington University, Rockville, MD 20852, USA.
J Obes. 2014;2014:421658. doi: 10.1155/2014/421658. Epub 2014 Jul 14.
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.
传统上通过参照标准生长图表的体重指数z评分（BMIz）来定义儿童肥胖。腰高比（WHtR）不依赖于性别和年龄参考标准。在“健康研究”的入组样本中，我们比较了BMIz和WHtR识别不良心脏代谢风险的能力。在来自42所中学的5482名六年级学生中，我们估计了BMIz或WHtR对心脏代谢风险因素（胰岛素抵抗（HOMA-IR）、血脂、血压和血糖）的解释变异（R²）和标准化β系数。对于每个风险结果变量，我们针对按性别和高肥胖与低肥胖分层的四个亚组准备了调整回归模型。对于HOMA-IR，在高肥胖学生中，归因于BMIz或WHtR的R²为19%-28%，在低肥胖学生中为8%-13%。对于血脂变量，在高肥胖学生中R²为4%-9%，在低肥胖学生中为2%-7%。在低肥胖亚组中，BMIz对总胆固醇/高密度脂蛋白胆固醇和甘油三酯的标准化系数（0.13-0.20）往往比WHtR（0.17-0.28）弱。在高肥胖学生中，BMIz和WHtR与西班牙裔和白人的血压相关，但与黑人男孩（收缩压）或女孩（收缩压和舒张压）无关。在11-12岁的儿童中，通过WHtR进行评估可以提供与传统BMIz类似的心脏代谢风险估计，而无需参照标准生长图表。
