Study on reference value of waist circumference percentile curve and abdominal obesity cutoff points of children and adolescents aged 6-20 in Macao.

BACKGROUND

To develop a standardized percentile curve of waist circumference and abdominal obesity cutoff points for children and adolescents aged 6 to 20 in Macao, the study established a reference for screening abdominal obesity in this population.

METHODS

The waist circumference data of 10,095 children and adolescents from the 2015-2020 Macao People's Physical Fitness Surveys were used for modeling. The GAMLSS model with four parameters of "median, standard deviation, kurtosis and skewness" was used to construct the standardized percentile curve of waist circumference. Then, the percentile curve-joining adult method was applied to establish the critical value of high waist circumference. Finally, the curves of this study were compared with relevant domestic and international data.

RESULTS

(1) Standard curves of waist circumference percentile and standard deviation unit curves were obtained for children and adolescents aged 6-20 years in Macao. (2) Waist circumference of children and adolescents in Macao increased with age. After the age of 12, waist circumference growth gradually decreased. The waist circumference of males was larger than that of females. (3) Analysis of different percentile curves revealed a divergence in growth rates between P50 and P90. Specifically, from ages 6-11 in boys and 6-10 in girls, the annual increase in waist circumference at P90 exceeded that at P50. After these ages, the growth rate at P50 surpassed that at P90.

CONCLUSION

The standardized curves constructed for the percentile waist circumference of Macao's children and adolescents were smooth and tests showed good validity. We recommend using these standardized percentile curves (applicable to ages 6-20 years) and abdominal obesity thresholds (applicable to ages 6-18 years), combined with the other evaluation commonly used indicator of obesity, to identify abdominal obesity in Macao's children and adolescents and therefore, to improve the well-being of Macao's children and adolescents.