Metabolic syndrome in adolescents: definition based on regression of IDF adult cut-off points.

OBJECTIVES

The objective of this study was to derive a sex- and age-specific definition of the metabolic syndrome (MetS) and its abnormalities for adolescents.

STUDY DESIGN

This is a cross-sectional study.

METHODS

A total of 1100 adolescent students, aged 12-18 y, were randomly selected from schools and classrooms in the city of Constantine, Algeria; all had anthropometric measurements taken, and 989 had blood tests. Gender-specific growth curves for components of the MetS were derived, using the LMS (lambda-mu-sigma) method, and the percentiles corresponding to the thresholds of the MetS components proposed for adults by the International Diabetes Federation (IDF) were identified.

RESULTS

The prevalence of the MetS using this new definition was 4.3% for boys and 3.7% for girls (P = 0.64). Overall, a high waist circumference was the most frequent of the syndrome components, but the frequency was much higher in girls than that in boys, 33.6% and 6.9%, respectively. In contrast, a high systolic blood pressure was seen in 26.8% of the boys and only 11.4% of the girls. The prevalence of the MetS was higher among adolescents with a body mass index (BMI) ≥95th percentile of the study population, 28.8%, against 9.8% in adolescents with a BMI between the 95th and 85th percentile and 1.8% in those with a BMI <85th percentile (P < 0.0001).

CONCLUSION

MetS during adolescence requires more studies to establish a consensus definition. For clinical practice, we propose a simplified definition for boys and girls based on regression of IDF adult cut-off points. This definition should be tested in further studies with other adolescent populations.