Background: The aim of this study was to compare bioelectrical impedance analysis (BIA) equations developed for healthy pediatric populations and for HIV-infected children using dual-energy X-ray absorptiometry (DXA) as the gold standard.
Materials and methods: A cross-sectional study was carried out with 40 prepubertal, HIV-infected children who regularly attended the Pediatric Infectious Disease Clinic at the Universidade Federal de São Paulo, São Paulo, Brazil. The study was conducted from August to November 2008. Demographic data, clinical parameters, immunological status, and use of antiretroviral therapy were obtained from the patients' medical records. We performed anthropometric parameters and body composition analyses, analyzed body composition by BIA and DXA, and compared the results obtained from BIA through using equations for both healthy and HIV-infected populations.
Results: The mean ± SD age of the study population was 9.8 ± 1.2 years. Half of the population were females, and 82.5% of the children were clinically classified as B and C. Total body fat, by both absolute mass and by percentage, exhibited high homogeneity between the results obtained from BIA and DXA. However, there was no concordance in fat-free mass. The equation for healthy children showed good sensitivity and specificity when comparing the percentage of total body fat measured by DXA.
Conclusion: BIA provides reliable data on total body fat but not fat-free mass when compared with DXA. The BIA equation developed for healthy pediatric populations can be used to determine total body fat in HIV-infected children.