Abdominal skeletal muscle quality and quantity are independently and jointly associated with cardiometabolic health in children.

Objective: To investigate the independent and joint associations between intermuscular abdominal adipose tissue and abdominal skeletal muscle tissue with cardiometabolic health indicators in children.

Methods: This cross-sectional study included 114 children (10.6 ± 1.1 y, 54% girls) and 56 children (11.3 ± 1.5 y, 39% girls) from two cohorts. Total abdominal area (TAA), intermuscular abdominal adipose tissue (IMAAT) and abdominal skeletal muscular tissue (AMT) were measured by magnetic resonance imaging. Cardiometabolic health was evaluated by triglycerides-to-HDL ratio (TG/HDL), mean arterial pressure (MAP), HOMA-IR and metabolic syndrome z-score (MetSynd).

Results: IMAAT was associated with higher MetSynd regardless of total adiposity in both cohorts (P < 0.05). In the EFIGRO project, the associations of IMAAT with HOMA-IR and TG/HDL ratio were independent of total adiposity (P < 0.05). The relationship of IMAAT with MAP was attenuated after controlling for total adiposity in both cohorts (P < 0.09). The AMT/TAA ratio was inversely associated with the TG/HDL ratio, MAP, HOMA-IR, and MetSynd in both cohorts (P < 0.01). Joint associations showed that children with high IMAAT and low AMT/TAA ratio had significantly higher HOMA-IR (P < 0.01) and MetSynd (P < 0.05) than those with low IMAAT and high AMT/TAA ratio in both cohorts.

Conclusions: Both high IMAAT and low AMT are associated to poor cardiometabolic health already in childhood.