Socio-economic position, cognitive function and clustering of cardiovascular risk factors in adolescence: findings from the Mater-University study of pregnancy and its outcomes

Objectives: The objectives of this study were to examine the extent of clustering of smoking, high levels of television watching, overweight, and high blood pressure among adolescents and whether this clustering varies by socioeconomic position and cognitive function. Methods: This study was a cross-sectional analysis of 3613 (1742 females) participants of an Australian birth cohort who were examined at age 14. Results: Three hundred fifty-three (9.8%) of the participants had co-occurrence of three or four risk factors. Risk factors clustered in these adolescents with a greater number of participants than would be predicted by assumptions of independence having no risk factors and three or four risk factors. The extent of clustering tended to be greater in those from lower-income families and among those with lower cognitive function. The age-adjusted ratio of observed to expected co-occurrence of three or four risk factors was 2.70 (95% confidence interval [CI], 1.80–4.06) among those from low-income families and 1.70 (95% CI, 1.34–2.16) among those from more affluent families. The ratio among those with low Raven’s scores (nonverbal reasoning) was 2.36 (95% CI, 1.69–3.30) and among those with higher scores was 1.51 (95% CI, 1.19–1.92); similar results for the WRAT 3 score (reading ability) were 2.69 (95% CI, 1.85–3.94) and 1.68 (95% CI, 1.34–2.11). Clustering did not differ by sex. Conclusion: Among adolescents, coronary heart disease risk factors cluster, and there is some evidence that this clustering is greater among those from families with low income and those who have lower cognitive function.