Laine Saara, Sjöros Tanja, Garthwaite Taru, Honka Miikka-Juhani, Löyttyniemi Eliisa, Norha Jooa, Eskola Olli, Koivumäki Mikko, Vähä-Ypyä Henri, Sievänen Harri, Vasankari Tommi, Hirvonen Jussi, Laitinen Kirsi, Houttu Noora, Kalliokoski Kari K, Saunavaara Virva, Knuuti Juhani, Heinonen Ilkka H A
Turku PET Centre, University of Turku, Åbo Akademi University, and Turku University Hospital, Turku, Finland.
Department of Biostatistics, University of Turku and Turku University Hospital, Turku, Finland.
Am J Physiol Endocrinol Metab. 2025 Jun 1;328(6):E756-E771. doi: 10.1152/ajpendo.00446.2024. Epub 2025 Apr 17.
Metabolic syndrome increases the risk of developing noncommunicable diseases such as metabolic dysfunction-associated steatotic liver disease. The aim was to investigate the effects of sedentary behavior (SB) reduction on liver glucose uptake (LGU), endogenous glucose production (EGP), liver fat content (LFC), and liver enzyme levels [alanine aminotransferase (ALT), aspartate aminotransferase, and γ-glutamyltransferase]. Forty-four sedentary (daily SB time ≥ 10 h), physically inactive middle-aged adults with metabolic syndrome were randomized into intervention (INT; = 23, 21 completed) and control (CON; = 21, 19 completed) groups. For 6 mo, INT aimed to limit SB by 1 h/day, whereas CON aimed to maintain usual habits. SB and physical activity (PA) were measured continuously with hip-worn accelerometers. Before and at the end of the intervention, LGU was measured using positron emission tomography during the hyperinsulinemic-euglycemic clamp. EGP was calculated, and LFC was measured by magnetic resonance spectroscopy. INT reduced SB by 51 [95% confidence interval (CI): 22, 78] min/day and increased moderate-to-vigorous physical activity (MVPA) by 22 (95% CI: 12, 33) min/day, with no significant change in CON. Differences in liver health markers between the groups were not significant. However, according to the exploratory analyses among participants who successfully reduced SB, ALT decreased (-1.1 [95% CI: 0.93, 1.36] U/L) compared with the continuously sedentary participants (+0.8 [95% CI: 0.65, 1.05] U/L) (group × time, = 0.006). To enhance liver health, reducing SB for longer durations and/or increasing the intensity of PA may be necessary. However, successfully reducing SB may lead to better levels of circulating ALT liver enzymes. Aiming to reduce sedentary behavior (SB) by 1 h/day did not significantly influence liver health markers, suggesting that more substantial reductions or a different approach might be necessary to see improvements. However, achieving the desired behavioral change could lead to improvements in ALT levels. This study is the first to analyze how reducing SB and replacing it with nonguided physical activity impacts liver health in adults with metabolic syndrome, offering insights for future intervention strategies.
代谢综合征会增加患非传染性疾病的风险，如代谢功能障碍相关脂肪性肝病。本研究旨在探讨减少久坐行为（SB）对肝脏葡萄糖摄取（LGU）、内源性葡萄糖生成（EGP）、肝脏脂肪含量（LFC）以及肝脏酶水平[丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶和γ-谷氨酰转移酶]的影响。44名久坐（每日SB时间≥10小时）、缺乏身体活动的中年代谢综合征患者被随机分为干预组（INT；n = 23，21人完成）和对照组（CON；n = 21，19人完成）。为期6个月，INT组旨在将SB时间限制为每天减少1小时，而CON组旨在维持日常习惯。使用佩戴在髋部的加速度计连续测量SB和身体活动（PA）。在干预前后，通过正电子发射断层扫描在高胰岛素-正常血糖钳夹期间测量LGU。计算EGP，并通过磁共振波谱测量LFC。INT组每天减少SB时间51[95%置信区间（CI）：22，78]分钟，中度至剧烈身体活动（MVPA）增加22（95%CI：12，33）分钟，CON组无显著变化。两组之间肝脏健康标志物的差异不显著。然而，根据对成功减少SB的参与者进行的探索性分析，与持续久坐的参与者（+0.8[95%CI：0.65，1.05]U/L）相比，ALT水平下降（-1.1[95%CI：0.93，1.36]U/L）（组×时间，P = 0.006）。为了改善肝脏健康，可能需要更长时间地减少SB和/或增加PA强度。然而，成功减少SB可能会使循环中的ALT肝脏酶水平更好。旨在每天减少1小时久坐行为（SB）对肝脏健康标志物没有显著影响，这表明可能需要更大幅度的减少或采用不同的方法才能看到改善。然而，实现预期的行为改变可能会导致ALT水平的改善。本研究首次分析了减少SB并用无指导的身体活动替代它对患有代谢综合征的成年人肝脏健康的影响，为未来的干预策略提供了见解。
