There is substantial cross-sectional data suggesting a link between childhood obesity and increasing cardiometabolic risk factors. However, little was known regarding the long-term relationships between child BMI trajectories and indicators of cardiometabolic risk. Therefore, for a study, researchers sought to identify unique BMI trajectories during childhood between the ages of 2 and 11 years and assess the correlation of these BMI trajectories with biomarkers of cardiometabolic risk between the ages of 7 and 11 years.

The study comprised 338 children from low-income and racially/ethnically diverse homes who took part in the NET-Works randomized intervention trial and the NET-Works 2 prospective follow-up study. BMI was assessed at baseline (when children were 2-4 years old) and at one, two, three, and five-year follow-up visits. The BMI measure determined at each time point was the percent of the 95th percentile of BMI (percent BMIp95). In addition, children (aged 7 to 11 years) completed tests for carotid to anterior tibial artery pulse wave velocity (PWV), C-reactive protein (CRP), leptin, adiponectin, and oxidized low-density lipoprotein (OLDL) during the 5-year follow-up visit (oxLDL). To identify kid %BMIp95 trajectory groupings, group-based trajectory modeling was performed. The correlations between %BMIp95 trajectory groups and PWV, CRP, leptin, adiponectin, and oxLDL were studied using adjusted linear regressions. 

They found two trajectory groups: 75% of children had a moderate-decreasing trajectory (baseline BMI was below the 95th percentile of BMI and followed a moderate-decreasing trajectory through time), and 25% had a marked-increasing trajectory (baseline BMI was above the 95th percentile of BMI and followed a steep increase over time). Children in the marked-increase trajectory group had higher mean adjusted CRP (3.3 mg/L, 95% CI [1.6, 4.9]) and leptin (62.5 ng/mL, 95% CI [44.0, 80.9]), but lower levels of adiponectin (-1.4 μg/mL, 95% CI [-2.5, -0.1]). PWV and oxLDL differences were modest and not statistically significant. 

Two distinct BMI trajectories were detected among children from low-income and racially/ethnically diverse families. Those with a constant BMI increase over time had a higher baseline BMI and worse inflammatory and adipokine profiles later in childhood compared to children with a consistent BMI decline over time. However, no variations in arterial stiffness were detected, which might arise later in adolescence or adulthood. This study adds to the objective data supporting the usefulness of early-life BMI surveillance using the %BMIp95 measure and lifestyle interventions to lower the risk of juvenile obesity and developing cardiometabolic risk.