不同减肥策略下肌内三酰甘油的积累情况；CENTRAL试验的子研究
Intramyocellular triacylglycerol accumulation across weight loss strategies; Sub-study of the CENTRAL trial.
作者信息
Gepner Yftach, Shelef Ilan, Schwarzfuchs Dan, Cohen Noa, Bril Nitzan, Rein Michal, Tsaban Gal, Zelicha Hila, Yaskolka Meir Anat, Tene Lilac, Sarusy Benjamin, Rosen Philip, Hoffman Jay R, Stout Jeffrey R, Thiery Joachim, Ceglarek Uta, Stumvoll Michael, Blüher Matthias, Stampfer Meir J, Shai Iris
机构信息
Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Institute of Exercise Physiology and Wellness, Sport and Exercise Science; University of Central Florida, Orlando, FL, United States of America.
出版信息
PLoS One. 2017 Nov 30;12(11):e0188431. doi: 10.1371/journal.pone.0188431. eCollection 2017.
BACKGROUND
Intramyocellular triacylglycerol (IMTG) is utilized as metabolic fuel during exercise and is linked to insulin resistance, but the long-term effect of weight loss strategies on IMTG among participants with abdominal fat, remain unclear.
METHODS
In an 18-month trial, sedentary participants with abdominal fat/dyslipidemia were randomized to either a low-fat (LF) or Mediterranean/low-carbohydrate (MED/LC) diet (including 28g·day-1 of walnuts). After 6-months, the participants were re-randomized to moderate intense physical activity (PA+) or non-physical activity (PA-). Magnetic resonance imaging (MRI) was used to quantify changes of IMTG, abdominal sub-depots, hepatic and intermuscular fats.
RESULTS
Across the 277 participants [86% men, age = 48 years, body-mass-index (BMI) = 31kg/m2, visceral fat = 33%] 86% completed the 18-m trial. At baseline, women had higher IMTG than men (3.4% vs. 2.3%, p<0.001) and increased IMTG was associated with aging and higher BMI, visceral and intermuscular fats, HbA1c%, HDL-c and leptin(p<0.05), but not with intra-hepatic fat. After 18 month of intervention and a -3 kg mean weight loss, participants significantly increased IMTG by 25%, with a distinct effect in the MED/LCPA+ group as compared to the other intervention groups (57% vs. 9.5-18.5%, p<0.05). Changes in IMTG were associated with visceral and intermuscular fat, metabolic syndrome, insulin and leptin (p<0.05 for all), however, these associations did not remain after adjustment for visceral fat changes.
CONCLUSIONS
Lifestyle strategies differentially affect IMTG accumulation; combination of exercise with decreased carbohydrate/increased unsaturated fat proportion intake greatly increase IMTG. Our findings suggest that increased IMTG during diet-induced moderate weight loss may not be directly related to cardiometabolic risk.
TRIAL REGISTRATION
ClinicalTrials.gov NCT01530724.
背景
肌内三酰甘油（IMTG）在运动期间用作代谢燃料，并且与胰岛素抵抗相关，但减肥策略对腹部脂肪参与者IMTG的长期影响仍不清楚。
方法
在一项为期18个月的试验中，将有腹部脂肪/血脂异常的久坐参与者随机分为低脂（LF）或地中海/低碳水化合物（MED/LC）饮食组（包括每天28克核桃）。6个月后，参与者重新随机分为中等强度体力活动（PA+）或非体力活动（PA-）组。使用磁共振成像（MRI）量化IMTG、腹部亚脂肪库、肝脏和肌间脂肪的变化。
结果
在277名参与者中（86%为男性，年龄=48岁，体重指数（BMI）=31kg/m2，内脏脂肪=33%），86%完成了18个月的试验。在基线时，女性的IMTG高于男性（3.4%对2.3%，p<0.001），IMTG增加与衰老、更高的BMI、内脏和肌间脂肪、糖化血红蛋白百分比、高密度脂蛋白胆固醇和瘦素相关（p<0.05），但与肝内脂肪无关。经过18个月的干预和平均体重减轻3kg后，参与者的IMTG显著增加了25%，与其他干预组相比，MED/LCPA+组有明显效果（57%对9.5-18.5%，p<0.05）。IMTG的变化与内脏和肌间脂肪、代谢综合征、胰岛素和瘦素相关（所有p<0.05），然而，在调整内脏脂肪变化后，这些关联不再存在。
结论
生活方式策略对IMTG积累有不同影响；运动与减少碳水化合物/增加不饱和脂肪比例摄入相结合可大大增加IMTG。我们的研究结果表明，饮食诱导的适度体重减轻期间IMTG增加可能与心脏代谢风险无直接关系。
试验注册
ClinicalTrials.gov NCT01530724。
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