RESUMO
OBJECTIVE: To establish normative data for lipoprotein subfractions using a novel ion mobility assay in healthy lean children and to compare their data with those of obese children preselected with normal glucose, blood pressure, and relatively normal lipids. STUDY DESIGN: Fasting blood samples in 162 children aged 7.0-18.9 years (75 lean [body mass index: 18.6 ± 6.6 kg/m(2)] and 87 obese [body mass index: 31.7 ± 5.4 kg/m(2)]) were analyzed. Correlation of lipoprotein subfractions with anthropometric and laboratory markers was performed. Principal component analysis was used to avoid using correlated variables. RESULTS: Normative data for lipid subfractions were obtained in healthy children. Lean children had higher high-density lipoprotein (HDL)-large (76%), HDL-small (13%), and HDL-total (27%) compared with obese (P < .01), and lower low-density lipoprotein (LDL)-medium (-30%, P < .01) and medium + small (-21%, P = .02) as well as LDL-total (-13%, P = .035). In both groups, the LDL component was higher in males and pubertal children (P < .01). Prepubertal children had a higher HDL component than pubertal ones (P < .004). Adjusting for sex and pubertal status LDL component was positively, and HDL component negatively, correlated with obesity (P < .004). CONCLUSIONS: Despite relatively normal triglycerides and cholesterol measured with standard assays at screening, ion mobility analysis showed significant differences in lipid and apolipoprotein subfractions between lean and obese children, even those prepubertal. Long-term, prospective follow-up may better characterize the predictability of lipid subfractions for future cardiovascular disease risk in children.