Section on Gerontology and Geriatric Medicine, Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina.
Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands.
J Appl Physiol (1985). 2020 Apr 1;128(4):872-883. doi: 10.1152/japplphysiol.00576.2019. Epub 2020 Mar 12.
Our objective was to determine the influence of a high-fat diet (HFD) on fasting and postprandial skeletal muscle substrate metabolism in endurance-trained (ET) compared with sedentary (SED) humans. SED ( = 17) and ET ( = 7) males were control-fed a 10-day moderate-fat diet followed by a 5-day isocaloric HFD (55% fat, 30% carbohydrate). Skeletal muscle biopsies were taken in the fasted condition and 4 h after a high-fat meal (820 kcals; 63% fat and 25% carbohydrate). Palmitate-induced suppression of pyruvate oxidation, an indication of substrate preference, and oxidation of fat and glucose were measured in homogenized skeletal muscle in fasted and fed states. Postprandial responses were calculated as percent changes from fasting to fed states. Postprandial suppression of pyruvate oxidation was maintained after the HFD in ET, but not SED skeletal muscle, suggesting greater adaptability to dietary intake changes in the former. Fasting total fat oxidation increased due to the HFD in ET skeletal muscle ( = 0.006), which was driven by incomplete fat oxidation ( = 0.008). Fasting fat oxidation remained unchanged in skeletal muscle of SED individuals. Yet, postprandial fat oxidation was similar between groups. Fasting glucose oxidation was elevated after the HFD in ET ( = 0.036), but not SED, skeletal muscle. Postprandial glucose oxidation was reduced due to the HFD in SED ( = 0.002), but not ET, skeletal muscle. These findings provide insight into differing substrate metabolism responses between SED and ET individuals and highlight the role that the prevailing diet may play in modulating fasting and postprandial metabolic responses in skeletal muscle. The relationship between high dietary fat intake and physical activity level and their combined effect on skeletal muscle substrate metabolism remains unclear. We assessed the influence of the prevailing diet in modulating substrate oxidation in skeletal muscle of endurance-trained compared with sedentary humans during a high-fat challenge meal. Collectively, our findings demonstrate the adaptability of skeletal muscle in endurance-trained individuals to high dietary fat intake.
我们的目的是确定高脂肪饮食（HFD）对耐力训练（ET）与久坐不动（SED）人类空腹和餐后骨骼肌底物代谢的影响。SED（= 17）和 ET（= 7）男性先接受 10 天中等脂肪饮食控制喂养，然后再接受 5 天等热量 HFD（55%脂肪，30%碳水化合物）。在空腹和高脂肪餐后 4 小时（820 千卡；63%脂肪和 25%碳水化合物）采集骨骼肌活检。在空腹和喂养状态下测量匀浆骨骼肌中棕榈酸诱导的丙酮酸氧化抑制作用（指示底物偏好）以及脂肪和葡萄糖的氧化作用。餐后反应计算为从空腹到喂养状态的百分比变化。ET 骨骼肌中的 HFD 后仍能维持餐后丙酮酸氧化的抑制作用，但 SED 骨骼肌中则不然，表明前者对饮食摄入变化具有更强的适应性。ET 骨骼肌中的 HFD 使空腹总脂肪氧化增加（= 0.006），这是由于不完全脂肪氧化（= 0.008）所致。SED 个体的骨骼肌中空腹脂肪氧化保持不变。然而，两组之间的餐后脂肪氧化相似。ET 骨骼肌中的 HFD 后空腹葡萄糖氧化升高（= 0.036），但 SED 骨骼肌中则不然。SED 骨骼肌中的 HFD 导致餐后葡萄糖氧化减少（= 0.002），但 ET 骨骼肌中则不然。这些发现提供了关于 SED 和 ET 个体之间不同底物代谢反应的深入了解，并强调了流行饮食在调节空腹和餐后骨骼肌代谢反应中的作用。高膳食脂肪摄入与体力活动水平之间的关系及其对骨骼肌底物代谢的综合影响仍不清楚。我们评估了流行饮食在调节耐力训练与久坐不动的人类在高脂肪挑战餐后骨骼肌中底物氧化中的作用。总的来说，我们的研究结果表明，耐力训练个体的骨骼肌具有适应高膳食脂肪摄入的能力。
