Blood Pressure Trajectory From Birth to Preschool and School Age in the ENVIRONAGE Birth Cohort

IMPORTANCE: 

Blood pressure (BP) is a crucial modifiable risk factor associated with cardiovascular disease in adulthood. The modifiable impact of BP may begin from birth and operate across the whole life span. However, no up-to-date studies have tracked BP from birth onward.

OBJECTIVE: 

To explore BP trajectory in childhood and evaluate whether the risk of hypertension later in childhood is associated with BP at birth and in early childhood.

DESIGN, SETTING, AND PARTICIPANTS: 

This cohort study evaluated data from the Belgian ENVIRONAGE birth cohort study with longitudinal follow-up visits in children aged 4 to 6 years (first follow-up [FU1]) and aged 9 to 11 years (second follow-up [FU2]). The study was initiated February 2, 2010, and data were collected and analyzed until August 30, 2024.

EXPOSURE: 

Childhood blood pressure.

MAIN OUTCOMES AND MEASURES: 

The main outcomes were incidences of elevated BP and hypertension at the last follow-up (FU1 or FU2). Tracking was assessed using change in mean arterial pressure (MAP) percentiles between 2 visits. Elevated BP and hypertension at childhood were standardized for age, sex, and height following the 2017 American Academy of Pediatrics guideline. Analyses were performed using multivariable-adjusted linear, mixed, and Cox proportional hazards regression models.

RESULTS: 

The study included 500 healthy children (mean [SD] gestational age, 39.2 [1.6] weeks; 266 girls [53.2%]), with 445 having 2 BP measurements and 55 having 3 BP measurements. From birth to FU1, mean (SD) systolic BP (SBP), diastolic BP (DBP), and MAP tracked from 67.3 (8.8) mm Hg, 40.5 (8.3) mm Hg, and (8.2) mm Hg, respectively, to 100.2 (8.5) mm Hg, 57.5 (9.1) mm Hg, and 74.6 (7.8) mm Hg, respectively. At FU2, mean (SD) SBP, DBP, and MAP tracked to 107.7 (9.5) mm Hg, 65.1 (6.4) mm Hg, and 82.1 (6.7) mm Hg, respectively. Per 1-SD increase in initial BP at birth or age 4 to 6 years, for all children in the combined dataset, BP at the last follow-up increased by 2.66 mm Hg (95% CI, 1.65-3.67 mm Hg) for SBP, 1.37 mm Hg (95% CI, 0.28-2.46 mm Hg) for DBP, and 1.97 mm Hg (95% CI, 0.85-3.10 mm Hg) for MAP. In the fully adjusted models, for each 1-SD increase in the initial MAP, the hazard ratios of elevated BP and hypertension were 2.84 (95% CI, 1.50-5.38) and 3.75 (95% CI, 1.79-7.86), respectively.

CONCLUSIONS AND RELEVANCE:

This prospective cohort study found that BP tracked consistently from birth through childhood. Higher BP levels at birth and early childhood were associated with an increased risk of elevated BP and hypertension later in childhood. These findings highlight the importance of monitoring and managing BP from birth as a potential strategy to reduce cardiovascular risk later in life.