[Prevalence of metabolic syndrome in a sample of Chilean children consulting in an obesity clinic]. / Síndrome metabólico en niños y adolescentes: asociación con sensibilidad insulínica y con magnitud y distribución de la obesidad.

BACKGROUND: In Chile between 1986 and 1998, the prevalence of obesity has increased from 4.6% to 24% in prepuberal and from 2.3% to 17% in puberal children. AIM: To assess the prevalence of metabolic syndrome (MS) in a sample of obese and overweight Chilean children. PATIENTS AND METHODS: Descriptive study in 489 children (273 females), aged from 6 to 16 years, consulting in an obesity program. Body mass index, Tanner puberal development, waist circumference, blood pressure, fasting blood glucose, insulin and lipid levels were measured. Insulin sensitivity was calculated using the mathematical models QUICKI and HOMA. MS was diagnosed when three or more of the following criteria were met: a waist circumference over percentile 90, a blood pressure over percentile 90, serum triglycerides over 110 mg/dl, HDL cholesterol of less than 40 mg/dl or a fasting blood glucose level over 100 mg/dl. RESULTS: MS was present in 4% of children with overweight and 30% of obese children. No differences in prevalence were observed for sex or puberal development. The most prevalent cardiovascular risk factors were abdominal obesity, present in 76% of the sample and high triclycerides levels in 39%. The less prevalent risk factor was a fasting blood glucose over 100 mg/dl in 3.7%. The risk for MS increased ten fold in children with severe obesity, compared with those with overweight. Those with abdominal obesity had a 17 times higher risk of MS. Basal insulin sensitivity was significantly associated with the number of cardiovascular risk factors and the presence of MS. CONCLUSIONS: In this sample of children, fat distribution and the severity of obesity were strong determinants of MS. Waist circumference had a higher impact on MS than body mass index.