A new randomized trial published in the American Journal of Physiology - Endocrinology and Metabolism has explored whether reducing on sedentary behavior (SB) could improve liver health markers in physically inactive, middle-aged adults with metabolic syndrome—a condition known to increase the risk of noncommunicable diseases such as metabolic dysfunction-associated steatotic liver disease. Despite promising behavioral changes, the intervention's overall effects on liver function were limited.
In the study, 44 sedentary individuals (spending ≥10 hours/day seated) were randomly assigned to either an intervention group (INT, n = 23) or a control group (CON, n = 21). The intervention group was instructed to reduce their SB by at least one hour daily for six months without structured exercise, while the control group was asked to continue their habits. SB and physical activity levels were tracked continuously using hip-worn accelerometers. At baseline and after six months, researchers measured liver glucose uptake (LGU) via positron emission tomography and calculated endogenous glucose production (EGP). They assessed liver fat content (LFC) with magnetic resonance spectroscopy. They analyzed liver enzyme levels, including ALT, AST, and γ-GT.
The intervention group had reduced their sedentary time by 51 minutes per day and increased moderate-to-vigorous physical activity (MVPA) by 22 minutes daily. On the other hand, the control group had no significant changes in behavior. Despite these improvements, no significant differences emerged between the groups in terms of LGU, EGP, LFC, or liver enzymes.
Participants who successfully reduced their SB demonstrated a significant decrease in ALT levels (−1.1 U/L). In comparison, ALT increased in participants who remained sedentary (+0.8 U/L).