Abdominal CT-derived metabolic phenotypes are associated with the MRI-derived brain age gap in women.

In joint models including both primary CT phenotypes and the same clinical covariates, FatRatio ( β = 0.095, p = 0.037) and liver-to-spleen attenuation ratio ( β = -0.115, p = 0.001) retained independent associations.

These findings persisted after age-bias correction of brain age gap and exclusion of extreme brain age gap outliers.

CT-derived markers added modest but significant explanatory value beyond conventional clinical covariates.