Relationship between waist circumference and cardiorespiratory fitness in Chinese children and adolescents: Results from a cross-sectional survey

Abstract

Background: This article assessed the relationship between waist circumference (WC) and cardiorespiratory fitness (CRF) of children and adolescents aged 7-18 years.

Methods: Using a stratified cluster random sampling method, 92,574 children and adolescents (47,364 males and 45,210 females) were extracted. CRF was measured by performance in the 20 m shuttle run test (20mSRT) and the subsequent estimation of maximal oxygen consumption ( $\dot{\text{V}}$ O_2max) using the Léger equations. Participants were divided into five groups of WC percentiles and three groups of CRF percentiles by the Lambda Mu Sigma (LMS). The correlation between WC and CRF was examined by one-way ANOVA and curvilinear regression analysis.

Results: WC increased with age, while $\dot{\text{V}}$ O_2max showed an age-related decline. Controlling for gender, urban, and rural factors, for children and adolescents aged 10-12, 13-15, and 16-18 years, the $\dot{\text{V}}$ O_2max Z-score of the normal WC group was significantly higher than the very low WC group (P < 0.05). Controlling for gender, urban, and rural factors, for participants aged 7-18 years, the $\dot{\text{V}}$ O_2max Z-score of the normal WC group was significantly higher than the high WC group and the very high WC group (P < 0.05).

Conclusions: It generally shows a "parabolic" trend between WC-Z and $\dot{\text{V}}$ O_2max-Z. The CRF among children and adolescents in the normal WC group is significantly higher than that in the low and the high WC groups.

Keywords: 20 m shuttle Run test; Cardiorespiratory fitness; Children and adolescents; Maximal oxygen consumption; Waist circumference.

Fig. 1

$\dot{\text{V}}$O_2max of Chinese children and adolescents aged 7–18 years in different waist circumference groups. Note: A = waist circumference < percentile 5; B = waist circumference ≥ percentile 5 and < percentile 15; C = waist circumference ≥ percentile 15 and < percentile 85; D = waist circumference ≥ percentile 85 and < percentile 95; E = waist circumference ≥ percentile 95.

Fig. 2

Relationship between WC-Z-score and $\dot{\text{V}}$O2max Z-score of children and adolescents.

Fig. 3

Standardized differences in 20mSRT (number of completed shuttles) performance between age-matched boys and girls for Chinese children and adolescents compared with the international values.