Racial and ethnic variations of metabolic indicators associated with childhood obesity: a comparative cross-sectional...

Susceptibility to adult metabolic diseases varies significantly across ethnicities. Asian adults exhibit elevated risks associated with obesity at lower body mass index (BMI) levels; whether similar patterns occur in pediatric populations remains unclear. This study aimed to evaluate how metabolic indicators associated with childhood obesity vary across diverse racial/ethnic groups.

Age-matched adolescents (12-18 years) from diverse regions across China-along with adolescents from Hispanic, Mexican American (MA), Non-Hispanic Black (NHB), Non-Hispanic White (NHW), and Other ethnic groups from the National Health and Nutrition Examination Survey (NHANES)-were enrolled. Comprehensive demographic, anthropometric and metabolic data-including glycemic parameters, lipid profiles, and insulin resistance indices-were analyzed. Cross-sectional mediation analysis was conducted to explore the potential biological pathways underlying the relationship between obesity (BMI standard deviation score [SDS] as the exposure) and metabolic dysfunction (metabolic indicators as the outcomes), testing cortisol and adrenocorticotropic hormone (ACTH) as potential mediators. Average direct and causal mediation effects were evaluated, with results interpreted as statistical associations consistent with the mediation framework.

The study included 632 adolescents (55.22% male, mean age 14.51 ± 1.87 years, median BMI 31.55 kg/m²). Compared to Chinese adolescents, NHB had higher HbA1c, NHW had lower HbA1c; both showed lower HOMA-β. All groups had higher HDL-C, lower total cholesterol and LDL-C levels than Chinese adolescents. HbA1c correlated positively with BMI SDS in Chinese and MA adolescents. Fasting insulin and HOMA-IR correlated positively with BMI SDS in all groups except Hispanic adolescents, while HOMA-β correlated positively in all groups except Hispanic and NHW adolescents. In Chinese adolescents, ACTH mediated the associations of BMI SDS with fasting insulin and HOMA-IR (P = 0.014 and 0.020 for mediation effects, respectively).

This first multiethnic pediatric metabolic comparison reveals distinct racial/ethnic patterns, with ACTH emerging as a novel mediator in Chinese adolescents. Findings underscore the need for ethnicity-tailored prevention strategies.