Racial/ethnic discrepancies in the metabolic syndrome begin in childhood and persist after adjustment for environmental factors

Abstract

Background and aims: Evaluation of metabolic syndrome (MetS) characteristics across an age spectrum from childhood to adulthood has been limited by a lack of consistent MetS criteria for children and adults and by a lack of adjustment for environmental factors. We used the pediatric and adult International Diabetes Federation (IDF) criteria to determine whether gender-specific and race-specific differences in MetS and its components are present in adolescents as in adults after adjustment for socio-economic status (SES) and lifestyle factors.

Methods and results: Waist circumference, blood pressure, triglycerides, HDL cholesterol, and fasting glucose measures were obtained from 3100 adolescent (12-19 years) and 3419 adult (20-69 years) non-Hispanic white, non-Hispanic black, and Mexican-American participants of the 1999-2006 National Health and Nutrition Examination Surveys. We compared odds of having MetS and its components across racial/ethnic groups by age group, while adjusting for income, education, physical activity and diet quality. After adjusting for possible confounding influences of SES and lifestyle, non-Hispanic-black adolescent males exhibited a lower odds of MetS and multiple components (abdominal obesity, hypertriglyceridemia, low HDL, hyperglycemia) compared to non-Hispanic-white and Mexican-American adolescents. Compared to non-Hispanic-white adolescent males, Mexican-American adolescent males had less hypertension. There were no differences in MetS prevalence among adolescent females, though non-Hispanic-black girls exhibited less hypertriglyceridemia.

Conclusion: Racial/ethnicity-specific differences in MetS and its components are present in both adolescence and adulthood, even after adjusting for environmental factors. These data help strengthen arguments for developing racial/ethnic-specific MetS criteria to better identify individuals at risk for future cardiovascular disease.

FIGURE 1

Adjusted Odds Ratios for Metabolic Syndrome Components by Age, Race, and Gender. OR's for non-Hispanic blacks and Mexican Americans are shown using non-Hispanic whites as the comparator group after adjustment for education level, income:poverty ratio, physical inactivity and dietary quality (Healthy Eating Index). Data are from NHANES ′99-′06 for all individuals with complete information regarding IDF MetS components. * p<0.05 vs. white non-Hispanic; ** p<0.01 vs. white non-Hispanics