Abstract Body: Introduction: High blood pressure (BP) is a modifiable risk factor for cardiovascular disease (CVD) and there is increasing recognition that BP elevations in early life track into adulthood. Higher BP during childhood may therefore confer long-term risk for CVD and CVD-related mortality.
Hypothesis: Children with higher BP at age 7 have higher risk of premature death from CVD.
Methods: Data are from a prospective cohort study of children born to over 40,000 pregnant women enrolled in the US Collaborative Perinatal Project between 1959-1965. BP was measured at age 7 by a pediatrician or nurse using a manual sphygmomanometer. Systolic BP (SBP) and diastolic BP (DBP) were converted to age-, sex-, and height-specific percentiles according to the American Academy of Pediatrics Guidelines. Children’s vital status (and for decedents, cause of death) through 2016 was ascertained via linkage to the National Death Index. Survival analysis was used to estimate associations of childhood BP with CVD mortality adjusted for childhood BMI, maternal race, education, and marital status, and study site. Fixed-effects regression was used to estimate associations within sibling clusters, controlling for shared familial and environmental characteristics.
Results: Among 38,252 included children, the mean SBP was 102 mmHg (SD: 10), the mean DBP was 61 mmHg (SD: 10), and the mean BMI was 16 kg/m² (SD: 2) at age 7. During a median follow-up of 54 years (interquartile range: 52, 55), there were 2,837 deaths from all causes, and 504 deaths from CVD. A 1-SD higher SBP (HR: 1.13 [95% CI: 1.03, 1.25]) and DBP (1.18 [1.07, 1.29]) was significantly associated with premature CVD mortality. Elevated BP (≥90^th percentile) was also associated with greater risk of CVD mortality (1.43 [1.19, 1.73], Figure 1). Findings were consistent in magnitude and direction in the fixed-effects sibling analysis (1,913 children in 819 sibling clusters) for a 1-SD higher SBP (1.15 [0.91, 1.46]) and DBP (1.19 [0.93, 1.53]).
Conclusion: Higher BP at age 7 was associated with greater risk of premature CVD mortality with >50 years of follow-up. The consistency in the magnitude of the associations within siblings mitigates concerns regarding unmeasured confounding due to shared family or lifestyle characteristics. The findings support the importance of early-life cardiovascular health promotion with a focus on monitoring and modifying BP-associated risk beginning as early as age 7 years.