Four measurement sites are commonly used in studies and tests : above the iliac crest, at the midpoint between the lowest rib and the superior border of the iliac crest, below the lowest rib, and at the narrowest waist. The requirement for a standardized anatomic point of WC measurement, which is selected as the best predictor of adverse cardiometabolic outcomes on a risk-weighted basis, has been proposed in previous studies. However, standardized protocols for WC measurement have not been established. Therefore, WC measurements provide unique predictive information regarding health risks. In multivariate regression models, WC is significantly more efficient than BMI in predicting health risk factors. Ĭompared with BMI, the WC of children provides a more reliable estimate of visceral adipose tissues measured with MRI at the level of the fourth lumbar vertebra (65% versus 56% variance). WC and related variables, such as waist circumference-to-hip circumference ratio and waist-to-height ratio, are regarded as reliable factors corresponding to the level of visceral adipose tissues these factors are associated with some risk factors of metabolic diseases among adults and children. Waist circumference (WC) has been extensively investigated as an indicator of extreme body fat and health risks among children and adults. Body mass index (BMI) is a highly recommended and widely used tool to define childhood obesity.
In large-scale population surveys and public health screenings, some anthropometric indices or variables are commonly used as surrogates for body fat. Therefore, body fat measurement is considered an essential aspect of childhood obesity research. Generally, overweight condition and obesity are defined as abnormal or excessive fat accumulation that poses human health risks. Other childhood clinical consequences include asthma, type 1 diabetes, low-grade systemic inflammation, sleep apnea, and musculoskeletal disorders, particularly those affecting the lower limbs and feet. Childhood obesity is significantly associated with the cardiovascular risk factors among children and adolescents. IntroductionĬhildhood obesity is a critical health challenge in the 21st century. Results indicate that standardizing the anatomic point for the WC measurements is necessary. The WC measurements at five commonly used sites among Chinese children are different from one another. The measured WCs were strongly correlated with FM, % BF, FM in the trunk, and % BF in the trunk. The WCs exhibited the following pattern: WC2 < WC1 < WC3 < WC4 < WC5 ( ) in males and WC2 < WC1 < WC4, WC3 < WC5 ( ) in females. The relationship of WC of each site with FM, % BF, FM in the trunk, and % BF in the trunk was examined through partial correlation. The WCs were then compared through ANOVA with repeated measurement. Body fat mass (FM), body fat percentage (% BF), body fat mass in the trunk (FM in the trunk), and fat percentage in the trunk (% BF in the trunk) were determined by dual-energy X-ray absorptiometry. WC was measured at five sites in 255 subjects aged 9–19 years: immediately below the lowest rib (WC1), at the narrowest waist (WC2), the midpoint between the lowest rib and the iliac crest (WC3), 1 cm above the umbilicus (WC4), and immediately above the iliac crest (WC5). This study compared the waist circumference (WC) measurements of Chinese children at different sites to determine the relationship between WC measurements and body fat.