| Based on two population-recruited surveys, I aimed to explore the use of body mass index (BMI) and waist circumference (WC) to predict clustering of cardiovascular risk factors and to investigate the associations of overweight/obesity with various lifestyle factors and cardiovascular risk factors in Hong Kong Chinese school children.;From the second cohort surveyed in 2007-2008 [n=2053,mean ages =13.0"b3.3 years (boys) and 13.6"b3.3 years (girls)], male gender and short sleep duration were associated with obesity in primary school children [OR=2.25 (1.38-3.68, p=0.001) and 2.88 (1.23-6.70,p=0.014)]. In secondary school children, long sleep duration was associated with a reduced risk of having high total cholesterol and low density lipoprotein cholesterol levels (all p<0.05). Gender, obesity status, pubertal stage, diastolic blood pressure and cardiovascular risk scores were significantly associated with physical activity levels (p<0.05).;In conclusions, BMI and WC are useful clinical tools to identify clustering of cardiovascular risk factors in Hong Kong Chinese adolescents. Overweight/obesity is independently associated with insulin resistance, SBP, hsCRP, ALT, low HDL-C, IGFBP-3, low to moderate levels of physical activity and reduced sleep duration in Hong Kong Chinese adolescents.;From the first cohort surveyed in 2003 (n=2012, median age=16 years), the optimal BMI thresholds were at the 78th percentile for girls and the 72nd percentile for boys. The respective values for WC were at the 77th percentile for girls and the 76th percentile for boys. The sensitivities and specificities of these cut-off values ranged from 72% to 80%. Compared with the groups with normal weight, high systolic blood pressure(SBP), increased insulin resistance (as measured by homeostasis model assessment, HOMA-IR), elevated high-sensitivity C-reactive protein (hsCRP) levels and low high-density lipoprotein cholesterol (HDL-C) levels were independently associated with overweight/obesity. Compared to adolescents in the lowest alanine aminotransferase (ALT) stratum, top stratum of ALT levels was associated with clustering of cardiovascular risk factors. Among subjects with IGF-1 and IGFBP-3 data available (765 boys and 877 girls), the top tertile of IGFBP-3 level was associated with increased odds of having overweight/obesity and clustering of cardiovascular risk factors when compared to the lowest tertiles (p for trend, all <0.05). |
