Depression and increased risk of non-alcoholic fatty liver disease in individuals with obesity.

Abstract.
Aims: The longitudinal relationship between depression and the risk of non-alcoholic fatty liver disease is uncertain. We examined: (a) the association between depressive symptoms and incident hepatic steatosis (HS), both with and without liver fibrosis; and (b) the influence of obesity on this association.
Methods: A cohort of 142 005 Korean adults with neither HS nor excessive alcohol consumption at baseline were followed for up to 8.9 years. The validated Center for Epidemiologic Studies-Depression score (CES-D) was assessed at baseline, and subjects were categorised as non-depressed (a CES-D < 8, reference) or depression (CES-D ⩾ 16). HS was diagnosed by ultrasonography. Liver fibrosis was assessed by the fibrosis-4 index (FIB-4). Parametric proportional hazards models were used to estimate the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).
Results: During a median follow-up of 4.0 years, 27 810 people with incident HS and 134 with incident HS plus high FIB-4 were identified. Compared with the non-depressed category, the aHR (95% CIs) for incident HS was 1.24 (1.15-1.34) for CES-D ⩾ 16 among obese individuals, and 1.00 (0.95-1.05) for CES-D ⩾ 16 among non-obese individuals (p for interaction with obesity <0.001). The aHR (95% CIs) for developing HS plus high FIB-4 was 3.41 (1.33-8.74) for CES-D ⩾ 16 among obese individuals, and 1.22 (0.60-2.47) for CES-D ⩾ 16 among non-obese individuals (p for interaction = 0.201).
Conclusions: Depression was associated with an increased risk of incident HS and HS plus high probability of advanced fibrosis, especially among obese individuals.