Predictive value of bioelectrical impedance analysis-measured body fat to abnormal lipid profiles in children and adolescents: the optimal cut-off values of body fat / 中华实用儿科临床杂志

ABSTRACT

Objective:To assess the predictive values of bioelectrical impedance analysis(BIA)-measured body fat indices to abnormal lipid profiles, and to preliminary propose optimal cut-off values of body fat in children and adolescents.Methods:Children and adolescents, aged 6-16 years, were selected from 30 schools (8 primary schools, 21 middle schools and one 12-year education school) in Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by adopting a stratified cluster sampling method from November 2017 to January 2018.Questionnaire survey, body mass index(BMI), body fat mass index (FMI), fat mass percentage (FMP) and four lipid profiles were conducted.Results:A total of 14 309 participants, aged (11.0±3.3) years, were enrolled in the analysis, with 49.9% boys.In boys and girls, the percentile values ( P60- P95) fitted by FMI and FMP with K-median-coefficient of variation(LMS) method were taken as the cutting points, and P75 values were selected as the cut-off points of excessive body fat for their better sensitivity, specificity, predictive value and area under curve (AUC) for identification of abnormal lipid profiles.Boys with FMI above P75 accounted for 28% of the total population, and controlling boys with FMI below P75 could prevent dyslipidemia of 8%-57%.FMI in girl population occupied about 26% of the above, and controlling FMI in girl population below this cut-off point may prevent dyslipidemia from 8%-42%.FMP observed similar results to FMI.Assessed by FMI or FMP with P75 cut-off values, adiposity performed better than BMI for recognizing abnormal lipid profiles in boys (AUC 52.4%-69.6% vs.50.2%-67.1%, P<0.05) rather than in girls ( P>0.05). In addition, when FMI or FMP beyond P90, the specificity of each abnormal lipid profiles was around 90%. Conclusions:The recommend cut-off points for body fat may be to assess children′s adiposity, and can be applied in preventive activities.