Repeated detection of non-alcoholic fatty liver disease increases the incidence risk of type 2 diabetes in young adults

Aim: This study aimed to investigate the effects of repeated detection of non-alcoholic fatty liver disease (NAFLD) on the incidence risk of type 2 diabetes in young adults. Materials and Methods: In this nationwide population-based observational study using data from the Korean National Health Insurance Service, approximately 1 125 015 young adults aged 20-39 years who underwent health screening four times between 2009 and 2013 were included. NAFLD was defined as a fatty liver index (FLI) of ≥60. Repeated detection of NAFLD scores was defined as the number of times the participants met the criteria for NAFLD (0-4). To account for the degree of repeated detection of NAFLD, weighted repeated NAFLD scores were scaled as a sum by assigning points (0 points for FLI <30, 1 point for 30 ≤ FLI < 60, and 2 points for FLI ≥60) ranging from 0 to 8 points. Results: The multivariable-adjusted hazard ratios of type 2 diabetes associated with repeated detection of NAFLD scores of 1, 2, 3 and 4 were 2.74 (95% confidence interval 2.57-2.921), 3.45 (3.221-3.694), 4.588 (4.303-4.892) and 6.126 (5.77-6.504), respectively. The incidence risk of type 2 diabetes increased significantly with repeated detection of the NAFLD score. In the analysis of the weighted repeated NAFLD score, the hazard ratios for the incidence of type 2 diabetes showed a significant continuous positive linear association with increasing scores. Conclusions: Repeated detection of NAFLD influenced the incidence risk of type 2 diabetes in young adults, and a higher degree of repeated detection of NAFLD was independently associated with the risk of type 2 diabetes in young adults.