Associations of the Triglyceride-Glucose Index and Body Fat Composition with Blood Pressure in Children and...

While the triglyceride-glucose (TyG) index is a recognized marker of cardiometabolic risk, its influence on blood pressure through body composition in children has not been fully elucidated.

This study aimed to investigate the associations between the TyG index and blood pressure in children and adolescents, and to examine the mediating role of body composition in this relationship.

A cross-sectional analysis was conducted using data from 408 children aged 6-17 years in Guangdong Province, representing a subsample of the National Nutrition and Health Systematic Survey for children aged 0-18 years in China. The participants underwent venous blood tests (TyG index calculation), body composition assessments (InBody 770 bioelectrical impedance analyzer), and blood pressure measurements. Linear/logistic regression and mediation analyses were performed to evaluate associations and mediating effects.

The TyG index showed the strongest positive associations with systolic blood pressure (SBP: β = 4.49, 95% CI 2.36-6.61; P<0.001) and diastolic blood pressure (DBP: β = 2.07, 95% CI 0.56-3.58; P=0.007). Elevated blood pressure risk was significantly linked to the TyG index (OR = 2.04, 95% CI 1.29-3.22; P=0.002) and obesity-related parameters, particularly the fat mass index (FMI: OR = 1.50) and waist‒hip ratio (WHR-z: OR = 2.10). Mediation analysis revealed partial indirect effects of body composition on the TyG-SBP association (total effect: 4.49, 95% CI 2.36-6.61) but no mediation effect for the TyG-DBP.

Our findings demonstrate that the TyG index is independently associated with elevated blood pressure in children and adolescents. Importantly, obesity-related body fat composition, especially measured by the FMI and WHR, partially mediates the association between TyG index and SBP.