Context: Knowledge about ethnic differences in cardiovascular disease (CVD) risk factors among children and young adults from national samples is limited.
Objective: To evaluate ethnic differences in CVD risk factors, the age at which differences were first apparent, and whether differences remained after accounting for socioeconomic status (SES).
Design: Third National Health and Nutrition Examination Survey, 1988-1994.
Setting: Eighty-nine mobile examination centers.
Participants: A total of 2769 black, 2854 Mexican American, and 2063 white (non-Hispanic) children and young adults aged 6 to 24 years.
Main outcome measures: Ethnicity and household level of education (SES) in relation to body mass index (BMI), percentage of energy from dietary fat, cigarette smoking, systolic blood pressure, glycosylated hemoglobin (HbA1c), and non-high-density lipoprotein cholesterol (non-HDL-C [the difference between total cholesterol and HDL-C]).
Results: The BMI levels were significantly higher for black and Mexican American girls than for white girls, with ethnic differences evident by the age of 6 to 9 years (a difference of approximately 0.5 BMI units) and widening thereafter (a difference of >2 BMI units among 18- to 24-year-olds). Percentages of energy from dietary fat paralleled these findings and were also significantly higher for black than for white boys. Blood pressure levels were higher for black girls than for white girls in every age group, and glycosylated hemoglobin levels were highest for black and Mexican American girls and boys in every age group. In contrast, smoking prevalence was highest for white girls and boys, especially for those from low-SES homes (77% of young men and 61% of young women, aged 18-24 years, from low-SES homes were current smokers). All ethnic differences remained significant after accounting for SES and age.
Conclusion: These findings show strong ethnic differences in CVD risk factors among youths of comparable age and SES from a large national sample. The differences highlight the need for heart disease prevention programs to begin early in childhood and continue throughout young adulthood to reduce the risk of atherosclerosis.