Association of serum 25-hydroxyvitamin D concentration with anthropometric measures in children and adolescents: the CASPIAN-V study.

BACKGROUND: Serum 25-hydroxyvitamin D (25(OH)D) concentrations reflect vitamin D status, with deficiency implicated as an underlying factor for many adverse health effects. This study aims to analyze the association between vitamin D status and different anthropometric measures in a large pediatric population. METHODS: This nationwide cross-sectional study was conducted in 2019 in blood samples obtained from school students of 30 provinces in Iran. Participants were 2596 children and adolescents aged 7-18 years. Weight, height, waist circumference (WC), hip circumference (HC), neck circumference (NC), and wrist circumference (WrC) were measured. Body mass index (BMI) and waist-to-height ratio (W/HtR) were calculated. Serum 25(OH)D concentrations were measured using chemiluminescent immunoassay. RESULTS: Participants consisted of 55% boys, 71.3% urban inhabitants, with a mean (SD) age of 12.1 (3.0) years. Overall, vitamin D deficiency was documented in 10.6% of participants, insufficiency in 60.4%, and sufficiency in 29% of the population studied. The mean of BMI and WC was higher in the vitamin D deficient than in the vitamin D sufficient group (19.31 kg/m2 and 69.24 cm vs. 18.34 kg/m2 and 65.73 cm, respectively, P < 0.01). Multivariate linear regression models revealed a significant association of vitamin D insufficiency with WC and W/HtR (P < 0.05). Likewise, in the multivariate regression models, vitamin D deficiency was associated with BMI, WC, and W/HtR (P < 0.05). CONCLUSION: Our findings on the inverse association between vitamin D status and some anthropometric measures underscore the importance of providing vitamin D by fortification and supplementation programs of vitamin D for the pediatric population. LEVEL OF EVIDENCE: V.

Is frequency of potato and white rice consumption associated with cardiometabolic risk factors in children and adolescents: the CASPIAN-V study.

BACKGROUND: This study evaluated the association of frequency of potato and rice consumption with cardiometabolic risk factors in children and adolescents. METHODS: This nationwide cross-sectional survey was conducted on 14,400 children and adolescents. Fasting blood was obtained from a sub-sample of 4200 randomly selected students. Physical examination and laboratory tests were conducted under standard protocols. Metabolic Syndrome (Mets) was defined based on the Adult Treatment Panel III criteria modified for the pediatric age group. The self-reported frequency consumption of white rice and potato was reported on a daily or non-daily basis. RESULTS: The participation rate for the whole study and for blood sampling were 99 and 91.5%, respectively. Overall, 49.4% of the participants were girls while 50.6% were boys. The frequency of daily consumption of white rice and potato was 84.4 and 21.3%, respectively. In the multivariable linear regression model, daily consumption of potato increased body mass index (ß: 0.05, SE: 0.20, p = 0.010), waist (ß: 0.63, SE: 0.24, p = 0.008), and hip circumferences (ß: 0.62, SE: 0.26, p = 0.019). Moreover, in the multivariable logistic regression, daily consumption of potato was significantly associated with an increased risk of overweight (OR: 1.21, 95% CI: 1.04-1.39, P = 0.012). The potato and rice consumption had no statistically significant association with other cardiometabolic risk factors. CONCLUSIONS: Daily consumption of potato was significantly associated with higher anthropometric measures, whereas rice consumption had no statistically significant association with cardiometabolic risk factors. Future research to examine the possible obesogenic effects of intake of potato on children and adolescents is recommended.

Validity of a continuous metabolic syndrome score as an index for modeling metabolic syndrome in children and adolescents: the CASPIAN-V study.

BACKGROUND: The purpose of the present study was to assess the validity of continuous metabolic syndrome score (cMetS) for predicting metabolic syndrome (MetS) and to determine the cutoff values in a representative sample of Iranian children and adolescents. METHODS: This national study was conducted among 3843 students, aged 7-18 years country during the fifth survey of a national school-based surveillance program. The cMetS was computed by standardizing the residuals of waist circumference, mean arterial blood pressure, high-density lipoprotein cholesterol, triglycerides, and glucose by regressing them according to age and sex and aggregating them. The optimal cut-off points of cMetS for predicting MetS were determined by the receiver operation characteristic (ROC) curve analysis in different gender and age categories. RESULTS: Totally, 3843 students (52.3% boys) with average age of 12.45 years were assessed. The mean of cMetS increased according to elevating the number of MetS components. The overall cMetS cut-off point was 1.76 (sensitivity 93% and specificity 82%) in total pediatrics. The area under the ROC curve was 94%. The values for boys and girls were 1.79 and 2.72, respectively. CONCLUSIONS: cMetS performed highly accurate in predicting pediatrics with MetS in all gender and age groups and it appears to be a valid index in children and adolescents.