Body mass index reference charts for individuals with Down syndrome aged 2-18 years

To develop Brazilian growth charts for body mass index (BMI-for-age) for individuals with Down syndrome (DS). The secondary objective was to compare the BMI-for-age with the Centers for Disease Control and Prevention standards (CDC).

A retrospective and cross-sectional growth study of 706 youth with DS (56.7% males) was performed in 51 centers in São Paulo state, Brazil. Weight and height were used to calculate the BMI (kg/m²). The LMS method was applied to construct the growth charts. Z-scores were based on the CDC 2000 growth standards.

The BMI-for-age reference charts showed excellent goodness of fit statistics for boys and girls with DS aged 2-18 years. At 2 years of age, the mean BMI Z-scores of boys and girls with DS were lower compared to those of the CDC (Z-score=-0.2). In contrast, children with DS aged 3-18 years had higher mean Z-scores for BMI-for-age when compared to those of the CDC (Z-scores=+0.2 to +1.3).

The BMI of Brazilian youth with DS differs from those references established by CDC. These are the first Brazilian BMI-for-age charts for individuals with DS and will hopefully guide clinicians and parents in the evaluation and management of the nutritional status in children and adolescents with DS in Brazil.