Early BMI Trajectories Linked to Higher Cardiometabolic Risk in Children

Key Takeaways

• In 1072 mother-child pairs from Tianjin, China, late obesity growth and persistent obesity growth trajectories from ages 1 to 7 were associated with higher cardiometabolic risk at age 8 than the control trajectory.
• The persistent obesity growth pattern had a larger effect estimate for age-8 cardiometabolic risk than the late obesity growth pattern.
• Among individual cardiometabolic risk traits, significant associations were mainly observed for hypertension.
• Greater excess BMI-years, earlier adiposity rebound, and greater conditional BMI Z-score gain during ages 3 to 5 and 5 to 7 were also associated with higher cardiometabolic risk.

A single body mass index value can miss how long excess weight accumulates before school age or how quickly that acceleration unfolds across early childhood. Investigators in Tianjin, China tracked repeated growth measures through infancy and the preschool years and paired them with school-age assessment of blood pressure, fasting glucose, and lipids.

The study involved a prospective observational cohort of 1072 mother-child pairs from Tianjin for 8 years. Height and weight were measured annually from ages 1 to 7, and blood pressure, fasting glucose, and lipid concentrations were assessed at age 8. Group-based trajectory modeling was used to identify body mass index patterns, and the analysis also assessed excess BMI-years, adiposity rebound (AR) age, and conditional body mass index Z-score gain during ages 1 to 3, 3 to 5, and 5 to 7. Generalized linear and logistic regression models examined associations with the modified continuous cardiometabolic risk score (modified cMetS) and cardiometabolic risk traits (CRTs).

Two adverse trajectories emerged against the control trajectory: late obesity growth pattern (LOGP) and persistent obesity growth pattern (POGP). Relative to the control trajectory, LOGP was associated with higher modified cMetS, with a beta of 0.88 (95% confidence interval [CI] 0.53 to 1.22), while POGP showed a beta of 1.59 (95% CI 0.87 to 2.31). The persistent pattern carried the larger effect estimate.

Odds of cardiometabolic risk traits were also higher for both adverse trajectories, with LOGP showing an odds ratio (OR) of 1.70 (95% CI 1.20 to 2.41) and POGP an OR of 3.91 (95% CI 1.92 to 7.99) versus the control trajectory. Significant individual-trait associations were mainly observed for hypertension. Greater excess BMI-years, earlier AR, and greater conditional body mass index Z-score gain during ages 3 to 5 and 5 to 7 were also associated with higher modified cMetS and CRT risk.

According to the investigators, late-rising and persistent obesity growth patterns in early childhood were associated with higher cardiometabolic risk at age 8, with the larger signal seen for persistent obesity growth. The broader pattern also implicated cumulative BMI burden, earlier AR, and faster later early-childhood BMI gain.

Clinician Questions

How were early-childhood BMI trajectories defined in the Tianjin cardiometabolic risk cohort?

Annual body mass index measurements from ages 1 to 7 were entered into group-based trajectory modeling, which identified named growth patterns that included late obesity growth and persistent obesity growth alongside a control trajectory.

Which BMI gain intervals were associated with higher cardiometabolic risk at age 8?

Greater conditional body mass index Z-score gain during ages 3 to 5 and 5 to 7 was associated with higher modified cMetS and CRT risk, alongside greater excess BMI-years and earlier adiposity rebound.

How narrowly should these findings be applied beyond Tianjin children?

The reported association is directly supported in children from Tianjin, China, followed through age 8 within this cohort's developmental and health-system context.