Central obesity in Yemeni children: A population based cross-sectional study

Aim: To establish percentile curves for central obesity indices and explore prevalence and correlates of central obesity among Yemeni children. Methods: Data were collected in 2008 as part of a cross-sectional population-based survey, including 1550 girls and 1564 boys aged 6 to 19 years enrolled in the HYpertension and Diabetes in Yemen (HYDY) study. Data collection was conducted at home by survey teams composed of two investigators of both genders. Study questionnaire included questions about demographics, lifestyle, and medical history. Anthropometric measurements included body weight, height, waist circumference (WC) and hip circumferences. Waist to hip ratio (WHR) and waist-to-height ratio (WHtR) were then calculated. Age- and gender-specific percentiles (reference curves) of WC, WHR and WHtR were obtained with the LMS method. The independent predictors of central obesity defined as 1) WC percentile ≥90th; 2) WHtR≥0.5; or 3) WC percentile ≥90th and WHtR≥0.5, were identified at multivariate logistic regression analysis adjusted for age, gender, urban/rural location, years of school education, sedentary/active life-style. Results: Percentile curves for WC, WHR and WHtR are presented. Average WC increased with age for both genders. Boys had a higher WC than girls until early adolescence and thereafter girls had higher values than boys. WHR decreased both in boys and girls until early adolescence. Thereafter while in boys it plateaued in girls it continued to decrease. Mean WHtR decreased until early adolescence with no gender related differences and thereafter increased more in girls than in boys towards adult age. Prevalence of central obesity largely varied according to the definition used which was 10.9% for WC ≥ 90th percentile, 18.3% for WHtR ≥ 0.5, and 8.6% when fulfilling both criteria. At adjusted logistic regression WC ≥ 90th percentiles and WHtR ≥ 0.5 were less prevalent in rural than in urban areas (OR 0.52, 95% CI 0.41 to 0.67 and 0.66, 0.54 to 0.79 respectively), being more prevalent in children with sedentary lifestyle rather than an active one (1.52, 1.17 to 1.98 and 1.42, 1.14 to 1.75 respectively). Conclusion: Yemeni children central obesity indices percentile curves are presented. Central obesity prevalence varied according to the definition used and was more prevalent in urban sedentary subjects.