Prevalence of obesity and associated risk factors in Chinese pre-school children aged 6 to 72 months old in Singapore

Abstract

Objective To examine the prevalence and associated risk factors for overweight and obesity in 6 to 72 month old preschool-aged Chinese children in Singapore Methods A population-based cross-sectional study was carried out among 3,009 Chinese children aged 6? to 72?month?old of Singapore in the STARS (A Study on Refractive Error, Amblyopia and Strabimus in Singapore Chinese Preschoolers). Disproportionate stratified random sampling of households was conducted in the Western and South-Western part of Singapore. Among 5,648 Chinese children aged 6? to 72?month?old recruited, 3,009 were participated with the response rate of 72.2%. Height and weight were measured by trained staffs using standard protocols. We defined overweight and obesity using BMI values, with cut-off values proposed by the Centers for Disease Control, the International Obesity Task Force and the Singapore BMI for age chart. Family history, physical activity, birth weight and other risk factors were obtained by interviews. Multivariate regression analysis was used to explore the associations between overweight/obesity and potential associated factors as well as body mass index and potential predictors.

Results The prevalence of overweight and obesity in 6? to 72?month?old Chinese children were 8.1% and 7.1% (?CDC BMI for age? reference), 7.6% and 3.9% (?IOTF BMI for age? reference) and 7.0% and 5.3% (?Singapore BMI for age? reference), respectively. An increasing linear trend in the prevalence of obesity with age was seen in both genders, using the ?CDC and IOTF BMI for age? references (p-trend=<0.001 and 0.001 for ?CDC and IOTF BMI for age? references, respectively). Boys were more likely to be obese than girls, using the ?CDC BMI for age? reference (OR=1.42, 95% CI: 1.02,1.97, p=0.03) although there was no statistically significant gender differences in the prevalence of overweight by all three references. Variables found to be associated with overweight/obesity include higher birth weight (p=<0.001), shorter duration of preschool hours per day (p=0.01), more television time (p=0.02), more reading/drawing/coloring activities time (p=0.02), more total sedentary time (p=<0.001) and lower father?s education level (p=0.01). After adjusting for other variables (age, gender and father?s education) in multiple logistic regression models, birth weight (p=<0.001) and total sedentary time (p=0.01) were positively associated with overweight/obesity whereas duration of preschool hours per day (p=0.004) was negatively associated. Birth weight (p=<0.001) and watching television time (p=0.01) were also positively associated with body mass index in multiple linear regression models after controlling for age, gender and father?s education. Conclusion The prevalence of overweight and obesity in Singapore Chinese children aged 6? to 72?month?old was lower than most other countries. Obesity was more common in boys than girls. Birth weight, duration of preschool hours and total sedentary activities time were significantly associated with overweight and obesity after multivariate adjustments. Associated factors for body mass index after multivariate adjustment were birth weight and time spent on watching television.