Revisiting the association between metabolic dysfunction-associated steatotic liver disease and sleep: Moving from correlation to causation.

The retrospective study by Hyatt et al reported that metabolic dysfunction-associated steatotic liver disease (MASLD) with fibrosis was associated with poorer sleep, which in turn correlated with worse life quality in patients with human immunodeficiency virus. While their findings were significant, some limitations warrant consideration. First, the cross-sectional design precludes causal relationships. Second, no subgroup analyses stratified were conducted, leaving it unclear which sleep disturbances may increase MASLD risk. Third, baseline differences between groups may have introduced confounding. To address these limitations, we conducted a Mendelian randomization analysis to minimize confounding and assess the potential causal relationship between sleep traits and MASLD. Mendelian randomization results indicated that sleep apnea significantly increases the risk of MASLD (P = 0.014), whereas no causal associations were identified for other sleep traits. These findings complement and extend those of Hyatt et al, providing further insight into the association between MASLD and sleep.