Body mass index assessment using three reference standards among school adolescents in Sokoto Metropolis, North-Western Nigeria

Abstract

Abstract:Background:Undernutrition and overweight in chil-dren co-exist in developing coun-tries and may persist into adult-hood. Interpretation of body massindex (BMI), a useful measure ofnutritional status in children re-quires age related reference stan-dards, many of which were devel-oped from different internationalsources. It is necessary to deter-mine which of these referencestandards is most suitable for usein the assessment of BMI distribu-tion among adolescents in Nige-ria.Objective:To determine theprevalence of thinness, over-weight and obesity using theWorld Health Organization(WHO), International ObesityTask Force (IOTF), and Centrefor Disease Control (CDC) refer-ence standards and assess theirlevel of agreement amongst ado-lescents in Sokoto metropolis.Methods:800 students were se-lected through multi-stage sam-pling technique from secondaryschools. BMI was classified ac-cording to three reference stan-dards (WHO, CDC, IOTF). Datawas analysed with SPSS version22. The level of agreement be-tween the reference standards indiagnosing nutritional status wasassessed using Kappa statistics.Level of significance was put at p<0.05.Results:The prevalence rate ofthinness was highest with theIOTF at 22.6% compared to19.4%, and 19.6% by the WHOand CDC respectively. The preva-lence rates of overweight and obe-sity were highest with the WHOreference standards at 7.0% and1.3% followed by the IOTF (6.1%and 0.6%) and lowest with theCDC (5.8% and 0.3%). Substantialagreement was observed betweenWHO and IOTF (Kappa = 0.77),while the level of agreement was0.68 for IOTF/CDC and 0.64 forWHO/CDC. All agreement statis-tics were significant (p < 0.001).Conclusion:The WHO and IOTFreference charts may be more suit-able for our population