Effects of individual components, time, and sex on prevalence of metabolic syndrome in adolescents.

OBJECTIVES: To examine selected clinical characteristics for cohorts of similar adolescents over 4 survey periods from 1999-2006, to examine changes in rates of adolescents who exceed cutoff points for individual components of metabolic syndrome (MetS), to describe sex differences in individual components of MetS, to describe changes in MetS prevalence from 1999-2006 using 4 common MetS definitions, and to describe sex differences in MetS prevalence from 1999-2006.

DESIGN: Cross-sectional, US representational National Health and Nutrition Examination Survey from 1999-2006.

SETTING: Mobile examination centers conducted by the Centers for Disease Control and Prevention.

PARTICIPANTS: For 1999-2000, 613 adolescents (aged 12-19 years); for 2001-2002, 892 adolescents; for 2003-2004, 857 adolescents; and for 2005-2006, 814 adolescents. Exclusions were pregnancy, taking insulin or diabetic pills, and incomplete measurements.

MAIN OUTCOME MEASURES: Fasting plasma glucose level, triglyceride level, high-density lipoprotein cholesterol level, waist circumference, and systolic and diastolic blood pressures.

RESULTS: Increases in fasting plasma glucose and high-density lipoprotein cholesterol levels and decreases in diastolic blood pressure were observed. Rates of adolescents exceeding cutoff points for fasting plasma glucose levels have increased. Compared with girls, adolescent boys had higher rates exceeding cutoff points for fasting plasma glucose and high-density lipoprotein cholesterol levels. Adolescent girls had higher rates exceeding cutoff points for waist circumference. The prevalence of MetS among adolescents has not changed. No sex differences in MetS prevalence were observed.

CONCLUSIONS: Some criteria for MetS have remained stable (triglyceride level and systolic blood pressure) and one has improved for boys (high-density lipoprotein cholesterol level), but waist circumference has increased in girls and the rate of an elevated fasting plasma glucose level has nearly doubled for both boys and girls. Adolescent MetS prevalence has remained stable from 1999-2006.