Heterogeneous body composition trajectories in infancy are associated with blood pressure in childhood: A latent class analysis

Background: Accelerated infant weight gain is associated with adult type 2 diabetes and hypertension and recent evidence suggests an effect on blood pressure (BP) already in childhood. However, the role of infant fat and lean tissue accretion patterns on childhood BP is unknown. We aimed to identify infants with distinct fat mass (FM) and fat-free mass (FFM) trajectories from 0-6 months of age and examined associations with BP at 4 years of age.

Material and methods: Air displacement plethysmography was used to measure body composition monthly from birth to 6 months of age in 364 Ethiopian infants. BP was assessed at 4 years of age. Data driven latent class trajectory models were used to establish distinct FM and FFM trajectories, and multiple linear regression to examine their associations with BP at 4 years of age adjusted for sex, weight and length at birth, 3 and 6 months of age.

Results: We identified four distinct FM and two distinct FFM growth trajectories (figure 1). Overall mean (SD) systolic BP (SBP) was 87.4 (6.8) mmHg and diastolic BP (DBP) was 52.9 (8.3) mmHg at 4 years of age. Compared to the "High intermediate FM" reference group, infants in the "Accelerated FM" group had a 3.8 mmHg (95%CI, 0.3; 7.4) higher SBP and 5.3 mmHg (95%CI, 1.1; 9.5) higher DBP. SBP was also significantly lower in the “Quadratic FFM” group compared to the “Linear FFM” reference group (figure 2).

Conclusions: Heterogeneous FM and FFM accretion patterns in infancy were identified and accelerated infant fat accretion was associated with higher BP in childhood. Association with other metabolic markers in childhood and long term disease risk should be further studied.