Association between high fatty liver index and development of colorectal cancer: a nationwide cohort study with 21,592,374 Korean

BACKGROUND/AIMS: In Korea, the incidence of colorectal cancer (CRC) and non-alcoholic fatty liver disease (NAFLD) has increased due to a westernized lifestyle. This study investigated whether a high fatty liver index that reflects NAFLD correlates with CRC. METHODS: Data from the National Health Insurance Corporation 2009 to 2012 were analyzed. NAFLD disease was defined as a fatty liver index > 60 in the absence of alcohol consumption of ≥ 30 g/day. RESULTS: NAFLD was identified in 2,543,649 (11.8%) of 21,592,374 participants. CRC was identified in 19,785 (0.8%) of participants with NAFLD (fatty liver index ≥ 60) and in 80,871 (0.6%) participants without NAFLD (fatty liver index < 30). Multivariate logistic regression analysis demonstrated an independent association between NAFLD and CRC after adjusting for other confounders (hazard ratio, 1.13; odds ratio, 1.12 to 1.15). In subgroup analyses, fatty liver index ≥ 60 was associated with CRC regardless of body mass index, but the association was more prominent in persons with a normal index. NAFLD, in the absence of diabetes, hypertension, or dyslipidemia, was more highly associated with CRC than when one or more of these conditions are present. CONCLUSIONS: CRC should be considered as a possibility in patients with fatty liver index ≥ 60, even in the absence of obesity or other metabolic syndromes.