Metabolically healthy obesity, its resolution, and the risk of incident hepatic steatosis in Chinese children: evidence from two prospective cohorts

INTRODUCTION: The prospective association between metabolically healthy obesity (MHO) and incident hepatic steatosis in children remains unclear. This study aimed to investigate the prospective associations of baseline MHO and its dynamic changes with incident hepatic steatosis in Chinese children. METHODS: We included 2,192 children aged 6-11 years, drawn from two prospective cohorts with approximately 4 years of follow-up. Weight status was classified using body mass index according to the World Health Organization growth charts, and metabolic status was defined based on International Diabetes Federation criteria. Changes in metabolic health phenotypes from baseline to follow-up were also assessed. Incident hepatic steatosis was defined by ultrasonographic steatosis and/or elevated alanine aminotransferase. RESULTS: MHO at baseline was associated with a significantly higher risk of incident hepatic steatosis (OR = 7.23, 95% CI: 4.73-11.07) compared with metabolically healthy normal weight (MHN). Relative to children who remained MHN at both time points, those with persistent MHO had a markedly higher risk of hepatic steatosis (OR = 9.40, 95% CI: 5.47-16.15). In contrast, transition from MHO to MHN was not significantly associated with incident hepatic steatosis (OR = 1.89, 95% CI: 0.24-15.10). DISCUSSION: Among Chinese children, baseline or persistent MHO was associated with an increased risk of incident hepatic steatosis. Importantly, conversion from MHO to MHN was not significantly associated with this risk, suggesting that the resolution of MHO may attenuate future hepatic risk. These findings extend the existing evidence on childhood obesity by highlighting the dynamic nature of MHO and support early weight management and liver health monitoring in children with obesity, irrespective of their baseline metabolic status.