Percentiles of waist-to-sitting-height ratio and its relationship with obesity and elevated blood pressure among children and adolescents in Shandong, China.

BACKGROUND: Waist circumference (WC) and related anthropometric indices have been recognized as useful measures of abdominal obesity. However, little is known about the association of waist-to-sitting-height ratio (WSHtR) with obesity and elevated blood pressure (BP).

PARTICIPANTS AND METHODS: Data for this study were obtained from a large cross-sectional survey of school children. A total of 6889 students (3438 boys and 3451 girls) aged 7-17 years participated in this study. Height, sitting height, weight, WC, triceps and subscapular skinfold thickness, systolic blood pressure (SBP), and diastolic blood pressure (DBP) of all participants were measured. WSHtR was calculated as WC divided by sitting height. The BMI cutoff points recommended by the Working Group on Obesity in China (WGOC) were used to define overweight and obesity. Relatively high BP status was defined as SBP and/or DBP greater than or equal to the 95th percentile for age and sex.

RESULTS: WSHtR was positively correlated with BMI, skinfold thickness, SBP, and DBP in both boys and girls in all age groups (7-17 years). Children and adolescents with high WSHtR (≥75th) had a higher prevalence of overweight and obesity and a relatively high BP compared with their peers with low WSHtR (<25th). The prevalence of overweight plus obesity was 0.57 versus 90.91% for boys and 0.81 versus 61.03% for girls, and the prevalence of relatively high BP was 6.78 versus 31.35% for boys and 6.04 versus 22.18% for girls.

CONCLUSION: Large WSHtR is associated with obesity and elevated BP. Our results suggest that WSHtR may be a new useful index for screening obesity and related health risks.