Metabolic Syndrome in Children and Adolescents
Metabolic Syndrome in Children and Adolescents
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).
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).
Inclusion Criteria:

 The study was conducted in children attending 5th and 6th grade in all 20 public schools of
 the Municipality of Puente Alto, Santiago, Chile. All students were invited to participate
 in the study. Parents or their representatives signed an informed consent form and
 boys/girls an informed acceptance form.

 Exclusion Criteria:

 Subjects not signing the informed consent or acceptance forms were excluded from the study.