Factors associated with the metabolic syndrome in a national sample of youths: CASPIAN Study.

BACKGROUND AND AIM: To date, research on the influence of environmental factors on metabolic syndrome (MS) among youths is limited. This study was conducted to investigate for the first time the association of these factors with MS in a large national, representative sample of children from a non-Western population. METHODS AND RESULTS: The study population comprised of 4811 students (2248 boys and 2563 girls) aged 6-18 years, living in six different provinces in Iran. MS, defined based on criteria analogous to those of the Adult Treatment Panel III, was detected in 14.1% of participants. A birth weight of >4000 g in boys and <2500 g in girls increased the risk of having the MS [OR, 95% CI: 1.4 (1.007, 2.05) and 1.2 (1.1, 1.4), respectively]. Poorly educated parents and a positive parental history of chronic disease were other risks factors associated with MS. Low levels of physical activity significantly increased the risk of having MS [boys: 1.3 (1.1, 1.7); girls: 1.4 (1.2, 1.6)]. The risk of MS increased in-line with the consumption of solid hydrogenated fat [boys: 1.2 (1.07, 1.3); girls, 1.3 (1.1, 1.5)] and bread made with white flour [boys: 1.6 (1.3, 2.1); girls, 1.4 (1.1, 1.7)]. In contrast, an increased frequency of consumption of fruits and vegetable, as well as dairy products decreased the risk of having MS. CONCLUSION: Considering the effect of modifiable lifestyle habits and birth weight on MS in youths, urgent public health approaches should be directed towards primordial and primary prevention of this rapidly growing problem.

First reference curves of waist and hip circumferences in an Asian population of youths: CASPIAN study.

The Objective of the present study is to develop the first age- and gender-specific reference curves for waist and hip circumferences in an Asian population of youths. This cross-sectional population survey was conducted in 2003-04 on a nationally representative sample of 21111 school-students living in urban (84.6%) and rural (15.4%) areas of 23 provinces in Iran. After anthropometric measurements, smoothed reference curves for waist and hip circumference (WC, HiC) and waist-to-hip ratio (WHR) were developed by the LMS method. In both genders, WC and HiC percentile values increased with age. For girls, the 50th to 95th percentile curves for WC 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 WHR curves of girls decreased with age until 15 years and began to plateau thereafter, whereas for boys the 25th to 95th curves had a plateau pattern. Comparison of the current reference curves with the British ones showed that in boys, the 5th and 50th percentile curves were similar in both studies, but the 95th percentile curve of our study was higher than the British curves. For girls, the 5th percentile curves of both studies were similar, but the 50th and 95th percentile curves of our study were higher than the British ones. These curves represent the first childhood WC, HiC and WHR reference curves obtained in Asia. These curves can provide baseline data for analysis of time trends, as well as for international comparisons.

Association of physical activity and dietary behaviours in relation to the body mass index in a national sample of Iranian children and adolescents: CASPIAN Study.

OBJECTIVE: To examine the relation of dietary and physical activity (PA) patterns with the body mass index (BMI), and the associations between these patterns among children. METHODS: A representative sample of 21 111 school students aged 6-18 years was selected by multistage random cluster sampling from 23 provinces in the Islamic Republic of Iran. PA and dietary pattern were assessed by self-administered validated questionnaires. FINDINGS: Fruit and vegetables, dairy products and snacks (salty, fatty or sweet) had a similar consumption frequency of approximately twice a day. The type of fat most frequently consumed was hydrogenated solid fat (consumed by 73.8% of families). The PA level was significantly higher among boys than girls, in rural than in urban residents, and in intermediate students than high-school students. Among boys, the frequency of consumption of vegetables and plant proteins (R(2) = 0.46); and among girls, the frequency of consumption of dairy products and fruits, as well as high PA level had a significant inverse association with BMI (R(2) = 0.57). Among boys, the low frequency of consumption of fruits, the time spent on PA and the energy expenditure; and among girls, the time spent on PA and the energy expenditure, had significant relationships with overweight. When controlling for covariates, PA levels had significant relationships with the frequency of consumption of all food groups. CONCLUSION: Unhealthy lifestyles make Iranian young people prone to chronic diseases later in life. When examining their health benefits, the interrelationship of dietary and PA behaviours should be considered.