Background: No studies have assessed the association between change in weight status and subclinical cardiovascular outcomes in children.

Objective: To examine the association of change in weight status over 2 years with carotid intima-media thickness (cIMT) among Chinese children.

Methods: A total of 1184 children aged 6-11 years at baseline with complete data were included, and there were 1073 children after excluding those with cIMT ≥ sex- and age-specific 90th percentile values at baseline. Overweight (including obesity) at baseline or follow-up was defined by criteria for overweight and obesity for Chinese school-aged children and adolescents. High cIMT at follow-up was defined as cIMT ≥ age- and sex-specific 90th percentile based on the study population at follow-up.

Results: Compared with children who were in persistent normal-weight group, those in the incident or persistent overweight groups had higher cIMT change (incident overweight: β = 0.0149, p < 0.05; persistent overweight: β = 0.0068, p < 0.05) and had higher odds of high cIMT at follow-up (incident overweight: odds ratio [OR] = 3.58, 95% confidence interval [CI] = 1.34-9.61; persistent overweight: OR = 13.41, 95% CI = 7.58-23.73). In contrast, there was no significant increase in cIMT change (β = 0.0106, p > 0.05) and odds of high cIMT (OR = 2.50, 95% CI = 0.69-9.01) in the resolution group.

Conclusion: Children who developed overweight or maintained overweight over 2 years had increased odds of high cIMT, whereas those able to resolve their overweight status had a similar odds of developing high cIMT in childhood at follow-up. These findings highlight the potential role of managing weight status among children to preserve vascular health.