This study shows that independent of race/ethnicity, economically disadvantaged youth had a worse CVD risk profile. The pattern of SEP-CVD risk factor associations was more noteworthy and consistent for proximal behavioral (sedentary behavior and tobacco exposure) than for metabolic risk factors (elevated non–HDL-C, HbA1c
, sBP, and hs-CRP). This study’s findings add to existing literature that shows household socioeconomic circumstances (20
) and access (to material, information, social, and environmental resources) affect health outcomes through shaping health-related awareness and behaviors (dietary preferences, activity levels, and tobacco use) (21
In our data, socioeconomic disparities in behavioral-environmental risk factors (physical inactivity and tobacco exposure) were similar in both sexes and more strongly evident among adolescents but not young adults. This may be related to similarly high prevalence of behavioral and anthropometric risks across all income tertiles in young adults. For example, we observed large differences between SEP strata in the prevalence of central obesity in boys and tobacco exposure in both sexes, among the youngest age-groups, which tended to diminish with age. This highlights how age-related transitions and social context adjustments (e.g., adoption of detrimental health behaviors in response to different psychosocial, environmental [school, college, and early career], or socioeconomic stressors) may contribute to behavioral and anthropometric changes.
Our data further highlight that the pathways mediating SEP influences on risk factor emergence are nonlinear and complex (22
). The sociodemographic and economic exposures that cumulatively define SEP are interconnected (1
). In particular, socioeconomic disparities in the U.S. mirror race/ethnicity differences with worse CVD risk profiles noted among minority race/ethnicity youth (8
). In analyses accounting for PIR (), we found NHB and MA youth exhibited significantly higher odds of obesity, central obesity, sedentary behavior, elevated sBP, elevated non–HDL-C, and elevated HbA1c
but also lower likelihood of tobacco exposure—these patterns were broadly consistent with 1988–1994 NHANES estimates (8
). Also, in keeping with previous estimates, lowest PIR group youth of all races/ethnicities were significantly more likely to be sedentary and exposed to tobacco. These findings identify specific behavioral risks among youth that can be targeted with health promotion strategies and highlight that poverty is associated with health risks among all race/ethnic groups.
These analyses are, however, cross-sectional. Thus, temporal and causal inferences are limited, as are estimations of population-level cardiovascular benefits from alleviating poverty in lowest PIR tertiles. We transparently used sophisticated imputation and sensitivity analyses to address limitations of missing income data; sensitivity analyses treating missing PIR data as a separate category showed CVD risk factor prevalence estimates in this group were no different from those in referent highest PIR tertile. Furthermore, our NHANES-derived estimates of households below poverty were consistent with those of the U.S. Census Bureau (19
). Also, although PIR is a robust indicator of current resources, we recognize that this national-level threshold cannot account for regional cost-of-living differences and does not comprehensively represent the multiple domains of SEP, each of which provides a unique lens on how disadvantage affects health. The limited number of per-survey observations precluded examination of CVD risk profile trends over time. Lastly, we focused on overarching SEP-CVD risk relationships and could not account for individual variability in growth, maternal and paternal BMI, and intrauterine exposures.
This study’s strengths are the following: large, nationally representative, high-response rate sample; use of objective outcome measures; exposure (PIR) that integrates variations in household need and purchasing power over time; design-adjusted statistical methods; and stratification by age and sex to account for pubertal changes and/or socially patterned differences between sexes.
These findings showing greater preponderance of behavioral CVD risks among youths from lowest-income households provide two important inferences. First, viewed in the context of established trends, these data forewarn of recurring health and economic burdens. Second, this study offers insights into meaningful avenues for intervention, reinforcing that poor SEP hinders achievement of positive lifestyle choices. These implications are discussed separately.
The U.S. Census Bureau (19
) estimates that during the past decade, 16–19% of those <18 years lived below the federal poverty level (for a family of four, annual household income <$17,463 [year 2000] and <$21,834 [year 2008]). This estimate has not varied greatly (range 15–23%) during the past 4 decades (10
). Since the previous national-level reported data (8
) collected 2 decades ago, our findings show persistent socioeconomic and health disparities among U.S. youth.
Early life socioeconomic conditions indirectly affect life course (adult SEP and health risks) (24
) plus foretell low SEP over ensuing generations. Early life opportunities (e.g., education) shape future occupation, income, parity, personal (self-esteem and resilience) and social capital (relationships and networks), and investments in opportunities for the next generation (1
). Moreover, metabolic, vascular, and orthopedic consequences associated with CVD risk cumulatively translate into high health care costs and potentially less productive life years, further reducing prospects of escaping low SEP.
Health-related behaviors are established early, and CVD risks persist into adulthood (25
). Sedentary behaviors and tobacco exposure were common among adolescents but ominously twofold higher among young adults, suggesting that earlier intervention may circumvent future burdens. Also, national youth surveillance shows that previous declines in tobacco use are leveling off and positive weight-related behaviors have both been declining, emphasizing the need to reenergize prevention and promotion programs. However, the complexity of constraints faced by disadvantaged groups necessitate that CVD prevention policies address multiple levels (8
). For example, since poverty contributes to low awareness of health risks, food insecurity, and restricted choice (21
), regulations targeting price and content of foods and beverages are less meaningful without greater affordability of healthy alternatives. In a similar manner, neighborhood planning and safety are requisites for promoting physical activity. Lastly, to achieve population-level benefits, health promotion programs must reach low-income minority populations.
This study reports the most recent youth CVD risk factor distributions across SEP strata and isolates relationships between income disparities and health behaviors. These results are hypothesis generating—to reduce health and sociodemographic disparities nationally, policies that attenuate the effects of socioeconomic stressors must be judiciously tested to evaluate if they enhance the effectiveness of health promotion strategies. Finally, since our data predate the current economic downturn that may impose greater disparities, it will be imperative to continue surveillance of disparities among children and youth.