Correlation of liver-to-spleen ratio on computed tomography with colorectal polyps

Aim of the study
To explore the correlation of the liver-to-spleen (L/S) ratio on computed tomography (CT) with colorectal polyps.

Material and methods
Consecutive participants from Jinling Hospital Affiliated to Nanjing University who underwent routine biochemical tests, colonoscopies, and CT between January 2018 and December 2019 were selected. The L/S ratio on CT was used to measure the liver fat content. Colonoscopy findings were applied to create the polyp-free group and colorectal polyp group. All included subjects were also classified in the non-alcoholic fatty liver disease (NAFLD) group or the non-NAFLD group according to the CT (L/S) ratio to identify risk factors for colorectal polyps. All data were analysed with SPSS 25 software.

Results
Among 481 participants, 27.8% (79/284) of the patients were diagnosed with NAFLD in the colorectal group, which was higher than the corresponding proportion of the polyp-free group [9.1% (18/197)]. In NAFLD patients, most adenomatous polyps were found in the transverse colon, and hyperplastic polyps were largely located in the rectum. Linear regression suggested that the CT (L/S) ratio correlated with the number of colorectal polyps and with the number of adenomatous polyps. After adjusting for confounding factors, multivariate analysis indicated that NAFLD was an independent risk factor for adenomatous polyps and hyperplastic polyps.

Conclusions
A lower CT (L/S) ratio (higher liver fat content) was significantly correlated with a higher risk of colorectal polyps. This finding suggested that NAFLD patients with a reduced CT (L/S) ratio need to undergo colonoscopy examinations to detect high-risk colorectal polyps in a timely manner.