Degree of Accuracy of the BMI Z-Score to Determine Excess Fat Mass Using DXA in Children and Adolescents

International Journal of Environmental Research and Public Health

Jose Antonio Quesada-Rico¹  Mercedes Rizo-Baeza²  David Monasor-Ortolá²  Asier Martínez-Segura²  Ana Pilar Nso-Roca³  Ernesto Cortés-Castell³  Francisco Sánchez-Ferrer³ 

[1] Department of Clinical Medicine, Miguel Hernández University of Elche, 03550 Elche, Spain;Department of Nursing, University of Alicante, 03690 Alicante, Spain;Department of Pharmacology, Pediatrics and Organic Chemistry, Miguel Hernández University of Elche, 03550 Elche, Spain;

关键词: BMI Z-score;    childhood obesity;    body composition;    fat mass;    growth charts;   

DOI  :  10.3390/ijerph182212114

来源: DOAJ

【 摘 要 】

Obesity is caused by fat accumulation. BMI Z-score is used to classify the different degrees of weight status in children and adolescents. However, this parameter does not always express the true percentage of body fat. Our objective was to determine the degree of agreement between the fat mass percentage measured by DXA and the stratification of weight according to BMI Z-score in the pediatric age group. We designed a descriptive cross-sectional study. The patients were classified as underweight/normal weight with Z-scores between −2 and +0.99, overweight from 1 to 1.99, obese from 2 to 2.99, and very obese ≥3. We included 551 patients (47% girls), with a mean age of 11.5 ± 2.8 years (3.7–18 years). Higher BMI Z-scores were associated with a higher percentage of total fat (p < 0.001). However, there were important overlaps between both parameters, such that the BMI Z-score classified patients with the same percentage of total fat mass as having a different nutritional status classification. In conclusion, the stratification of weight status according to BMI Z-score revealed that 46.7% of patients had a fat percentage that did not correspond to their classification. For a more accurate weight assessment in clinical practice, we recommend combining anthropometric indices with diagnostic tools that better correlate with DXA, such as electrical bioimpedance.

【 授权许可】

Unknown