Introduction: Diastolic blood pressure (DBP) instead of systolic BP (SBP) or pulse pressure (PP) has been suggested as an important predictor for cardiovascular disease (CVD) events in those <50 years of age. Observations in those ages 18 to 30 years are sparse, and racial differences are also unknown.
Methods: Using data from the Coronary Artery Risk Development in Young Adults (CARDIA), which recruited healthy black and white young adults ages 18 to 30 years (n=4880) in 1985-1986, we assessed the associations between distinct BP components (SBP, DBP, mean arterial pressure [MAP], and PP) and incident CVD, defined as a composite endpoint of CVD deaths, myocardial infarction, angina, stroke, and heart failure.
Results: The mean SBP, DBP, and PP at baseline (mean age 25 years) were 112, 69, and 43 mmHg in blacks (n=2473) and 109, 68, and 41 mmHg in whites (n=2407), respectively. Over 25 years of follow-up (100,291 person-years), 210 CVD events (140 events in blacks) occurred before the age of 55. Results from Cox proportional hazards models suggest that SBP was superior to DBP for predicting incident CVD in blacks, while DBP was superior to SBP in whites (Table). In blacks, CVD risk associated with higher PP was significant in models including MAP. Significant interactions were found between race and PP (P=0.02) but not SBP (P=0.14) and DBP (P=0.38) in association with incident CVD risk.
Conclusions: In this long-term follow-up study, SBP outperformed DBP for predicting incident CVD in young blacks, while DBP outperformed SBP in young whites. In blacks, higher PP, representing large arterial stiffness, was associated with CVD risk. These racial differences may be attributable to earlier development of arterial stiffness in blacks compared with whites.