Computed tomography-based measurements of fat quality are associated with the prognostic nutritional index in gastric cancer patients

Malnutrition is common among gastric cancer (GC) patients and is associated with poor prognosis. Computed tomography (CT) measurements of the amount of visceral fat (VF) provide insights into nutrition status but the importance of fat density is unknown. The main objective of this prospective study was to examine the association between fat density and a nutrition-related index. The Prognostic Nutritional Index (PNI), which combines serum albumin and total lymphocyte count, was employed. Fat attenuation by 70-keV virtual monochromatic imaging (VMI), fat density by dual-energy CT (DECT), and bioelectrical impedance analysis (BIA) were used to assess the body composition of 54 GC patients. VMI- and DECT-based measurements of fat attenuation and density were negatively correlated. Regardless of sex, the PNI correlated with both VMI and DECT measurements of fat attenuation and density. Serum albumin levels also correlated with both fat attenuation and density. Because serum albumin levels regulate leakage of intravascular fluid into tissues, BIA was used to determine the extracellular water (ECW)/total body water (TBW) ratio. Importantly, the ECW/TBW ratio correlated with PNI, serum albumin, fat attenuation and fat density. Collectively, these findings indicate that PNI and serum albumin levels are associated with extracellular fluid balance and fat imaging characteristics.