Is the association of continuous metabolic syndrome risk score with body mass index independent of physical activity? The CASPIAN-III study

BACKGROUND/OBJECTIVES: Although the association of body mass index (BMI) with metabolic syndrome (MetS) is well documented, there is little knowledge on the independent and joint associations of BMI and physical activity with MetS risk based on a continuous scoring system. This study was designed to explore the effect of physical activity on interactions between excess body weight and continuous metabolic syndrome (cMetS) in a nationwide survey of Iranian children and adolescents. SUBJECTS/METHODS: Data on 5,625 school students between 10 and 18 years of age were analyzed. BMI percentiles, screen time activity (STA), leisure time physical activity (LTPA) levels, and components of cMetS risk score were extracted. Standardized residuals (z-scores) were calculated for MetS components. Linear regression models were used to study the interactions between different combinations of cMetS, LTPA, and BMI percentiles. RESULTS: Overall, 984 (17.5%) subjects were underweight, whereas 501 (8.9%) and 451 (8%) participants were overweight and obese, respectively. All standardized values for cMetS components, except fasting blood glucose level, were directly correlated with BMI percentiles in all models (P-trend < 0.001); these associations were independent of STA and LTPA levels. Linear associations were also observed among LTPA and standardized residuals for blood pressure, high-density lipoprotein, and waist circumference (P-trend < 0.01). CONCLUSIONS: Our findings suggest that BMI percentiles are associated with cMetS risk score independent of LTPA and STA levels.

Methodology and early findings of the fourth survey of childhood and adolescence surveillance and prevention of adult non-communicable disease in Iran: the CASPIAN-IV study

The fourth survey of the surveillance system named ''childhood and adolescence surveillance and prevention of adult non-communicable disease'' [CASPIAN-IV study], was conducted among a national representative sample of Iranian students. This paper describes the methods and early findings of this survey. This nationwide school-based study was conducted in 2011-2012 in 30 provinces of Iran among 13,486 students, 6-18 years [6640 girls, 75.6% from urban areas] and one of their parents. Mean age of students was 12.5 years. Based on the World Health Organization growth curves, 12.2% were underweight, 9.7% overweight and 11.9% were obese. Abdominal obesity was observed in 19.1% of students. The dominant type of cooking oil in urban families was liquid oil and hydrogenated fat [39% and 32%], most rural families used hydrogenated fat [53%], respectively. A total of 18% of students had at least 30 min of daily physical activity; 41% of students used computer in weekdays and 44% used it in weekends. Almost 34.5% of students reported to have at least one cigarette smoker and 21.5% reported to have a waterpipe smoker in their relatives. Moreover, 20.3% of students reported that they had suffered an injury needing the help of school health providers during the year prior to the study. Current evidence on the health risky behaviors among Iranian children and adolescents confirms the importance of conducting comprehensive surveillance surveys to identify health risk behaviors. Data of this survey and the trend of variables provide necessary information for health policy makers to implement action-oriented interventions

[Effects of milk replacement with regular yogurt and probiotic yogurt on blood lipid profiles of hypercholesterolemic and normocholesterolemic individuals]

Milk and fermented milk products have been known as foods with possible hypocholesterolemic effects. In this study we compared the effects of milk replacement with regular and probiotic yogurt in normocholesterolemic [N] and hypercholesterolemic [H] subjects. Twenty eight subjects with total serum cholesterol 160-280 mg/dl were included. They did not consume yogurt for 2 weeks after that 300 g/day of milk was added to their diet. Then, blood lipids were measured and they were randomly allocated to 2 groups to receive either 300g/day of ordinary yogurt or probiotic yogurt for 6 weeks as a substitution for milk. Blood lipid tests were repeated at the end of the study. Subjects in both groups were divided into these two subgroups according to their baseline blood cholesterol level: subgroup N [cholesterol < 220 mg/dl] and H [cholesterol >/= 220mg/dl]. Blood lipid changes were compared between these subgroups in each experimental group. Total cholesterol and LDL-C levels reduced in the H as compared to N subgroup after regular yogurt consumption instead of milk and the reduction of LDL-C was significant [P=0.033]. The effect of milk replacement with probiotic yogurt on total cholesterol and LDL-C reduction in H compared to N subgroup was higher than regular yogurt consumption [P=0.028 and P=0.014 for total cholesterol and LDL-C respectively]. The higher the baseline blood cholesterol level, the more beneficial effects of milk replacement with yogurt, especially probiotic yogurt. So, it is suggested for hypercholesterolemic individuals to consume more yogurt as the source of dairy products in their diet