Anthropometric indices and cardiovascular disease risk in children and adolescents: CASPIAN study

Abstract

For the first time in the Eastern Mediterranean region, we assessed the anthropometric indices most closely correlated to cardiovascular disease risk factors in a large nationally representative sample of children and adolescents to be used as a simple tool for identifying those at risk. We also developed the first age- and gender-specific reference curves for waist and hip circumferences in an Asian population of children and adolescents. This cross- sectional population survey was conducted in 2003-2004 on a nationally representative sample of 21,111 school-students living in urban (84.6%) and rural (15.4%) areas of 23 provinces in Iran. Biochemical variables were determined in a subsample of 4,811 participants. The correlation of anthropometric indexes and cardiovascular disease risk factors were determined by using Receiver Operator Characteristic (ROC) curves and partial correlation. Furthermore, smoothed reference curves for waist and hip circumference and waist-to-hip ratio were developed by the LMS method. In both genders, waist and hip percentile values increased with age. For girls, the 50th-95th percentile curves for waist circumference had a sharp increase between 8 and 13 years and 11-15 years, respectively, and began to plateau after this age, whereas for boys, these curves had a persistent and less sharp increase with age until the age of 18 years. The most prevalent cardiovascular disease risk factors were low levels of highdensity lipoprotein-cholesterol (28%), followed by hypertriglyceridemia (20.1%), and overweight (17%). Among anthropometric indexes, body mass index (BMI) and waist circumference (WC) had the highest correlation (r = 0.77, p < 0.0001 in boys, and r = 0.82, p < 0.0001 in girls).The ROC analyses showed that among boys, all anthropometric indices had the same association with cardiovascular disease risk factors in 6-9.9-year-age group, while in the 10-13.9 and 14-18-year-age groups, respectively WC and BMI had the strongest association. Among girls, these indices were BMI and waist to stature ratio (WSR), WC and WSR, and WC, respectively. The obtained curves can provide baseline data for analysis of time trends, as well as for international comparisons. In the CASPIAN study, BMI, WC and WSR were more closely correlated with cardiovascular disease risk factors. Considering the close correlation between different anthropometric indices studied, and differences in the best predictive index according to age and gender, it may be clinically useful in the pediatric population to routinely measure WC and WSR in addition to BMI as a screening tool to identify high risk youths.