Estimation of percent body fat based on anthropometric measurements in children and adolescents with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.
OBJECTIVE
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is associated with a high risk for obesity. Anthropometric measures are simple and inexpensive methods to assess body fat. However, the accuracy of alternative methods in these patients is unknown. This study aim to develop and evaluate the accuracy of predictive anthropometric equations in the estimation of percent body fat in individuals with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.


METHODS
A total of 31 female and 22 male patients, aged 7-20 years, were evaluated. Dual-energy X-ray absorptiometry was used as the reference method for body fat, and anthropometric measurements were performed.


RESULTS
Three new predictive equations showed similar results: Equation (1) (R² = 0.85; SEE = 2.89%), Equation (2) (R² = 0.86; SEE = 2.82%), and Equation (3) (R² = 0.86; SEE = 2.81%). Internal cross-validation procedures showed a high R² (range, 0.84-0.85) and low SEE (<3%). The limits of agreement ranged from -5.6% to 5.6% and no trend was observed.


CONCLUSIONS
In children and adolescents with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, three new predictive equations were validated for the estimation of percent body fat, with dual-energy X-ray absorptiometry as the reference method.
Growth and Body Composition Laboratory, Center for Investigation in Pediatrics (CIPED), Faculty of Medical Sciences (FCM), State University of Campinas (UNICAMP), Campinas, SP, Brazil. ezequiel@fcm.unicamp.br
Ezequiel M
EM
Gonçalves
Analiza M
AM
Silva
Catarina N
CN
Matias
Sofia H V
SH
Lemos-Marini
Allan O
AO
Santos
Gil
G
Guerra-Júnior
D015502:Absorptiometry, Photon; D050154:Adiposity; D000293:Adolescent; D041923:Adolescent Development; D000312:Adrenal Hyperplasia, Congenital / Q000473:pathology / Q000503:physiopathology*; D000328:Adult; D000465:Algorithms; D000886:Anthropometry / Q000379:methods; D015992:Body Mass Index; D001837:Body Weights and Measures; D002648:Child; D002657:Child Development; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009765:Obesity / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D050177:Overweight / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D012727:Sex Characteristics; D055815:Young Adult