Metabolic Syndrome in Children and Adolescents
Condition: Children; Cardiovascular; Risk Factors
MeSH terms: Metabolic Syndrome
Study type: Observational

Summary: 
      The purpose of this study was to cross-sectionally evaluate nutritional status and the
      metabolic syndrome in a sample of school-age children 10-15 years of age from 20 public
      schools in Santiago, Chile. In addition, the investigators retrospectively assessed the
      association of those variables with perinatal variables (birth weight, birth length, and
      gestational age at delivery).
    

Detailed description: 
      Subjects and methods Subjects The study was conducted in 2009-2011 in a cross-sectional way
      in 3,325 children attending 5th and 6th grade in 20 public schools of Santiago, Chile. All
      students were invited to participate in the study.

      Anthropometry and other physical examinations Field measurements were performed by a nurse
      and a nutritionist. Height and weight were measured with children barefoot and lightly
      clothed using a stadiometer and a beam-scale Seca ®, with an accuracy of 50 g. The individual
      height and weight values were established by averaging three measurements of each parameter.
      BMI was calculated and expressed in percentiles and z-scores (13): z-scores were calculated
      according to Center for Disease Control-National Center of Statistics 2000. Nutritional
      status was classified according to BMI percentiles in the obese category as ≥ 95 (14). WC was
      measured with an inextensible tape on the upper lateral border of the right ilium in the
      mid-axillary line at the end of an exhalation (15) ; two measurements were averaged and the ≥
      90th percentile was used as cutoff value (16). The triceps and subscapular skin folds were
      measured with a Harpenden ® caliper using a standard technique (15); both were used to
      calculate the percentage of FM using Slaughter equations (17) previously validated in Chilean
      children (18, 19). Elevated FM was established as ≥ 42% for girls with 10-15 years old, ≥ 38%
      for boys with ≤ 12 years old, and 40% for boys with ≥ 13 years old (20).

      A Critikon ® Dinamap Pro 100 BP monitor was used according to international norms and the
      averages of three measurements of systolic BP (SBP) were obtained and classified as abnormal
      using the ≥ 90 percentile of the same reference (21). A voluntary private self-report of
      pubertal status was requested by observation of standardized photos of breast development in
      girls and genitalia in boys including the presence of pubic hair (22). Maternal years of
      education were registered to estimate socio-economic level (23).

      Blood samples Subjects were instructed to fast (water was allowed) for 12 hours prior to
      drawing of blood; non compliers were asked to return another day for the blood sampling. A
      single laboratory was used for all blood analyses at the Faculty of Medicine, Pontificia
      Universidad Católica de Chile.

      Fasting venous blood samples were collected for determination of glucose (Gluco-quant method,
      Glucose / Hexokinase, Roche Diagnostics GmbH, Mannheim) and insulin (immunoassay direct
      luminometer chemotherapy, ADVIA Centaur ® XP, Bayer HealthCare LLC, Kyowa Medex Co. Japan);
      this method measures concentrations of insulin from 0.5 to 300 mUI / mL (sensitivity 0.5 mUI
      / mL) with a coefficient of variation of 3.48% and 6.17% for concentrations of 23.51 mUI / mL
      and 62.49 mUI / mL. respectively. Triglycerides and HDL-C were analyzed on the Modular
      Analytics P-800 platform (Roche Diagnostics GmbH, Mannheim, Germany).
    

Intervention name(s): anthropometric measures of fatness
Intervention type(s): Diagnostic Test
Intervention description(s): The aim of this study was to determine the discrimination capacity for cardiovascular risk factors of BMI, fat mass (FM), waist circumference (WC), and waist to height ratio (WHtR) in a population of Chilean children from Puente Alto County. Additionally, new cutoff points were established and compared with those described by other authors
Observational model: Other
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Initially 5,614 students were eligible for the study (2,616 females and 2,998 males) but
        2,289 students refused to participate (34.5% females and 47.4% males (p <0.001)). A total
        of 3,325 children and adolescents who presented a signed informed consent were included. No
        significant differences in age and years of maternal education were found between the study
        subjects and those who refused to participate.