Ramel A, Martinéz A, Kiely M, Morais G, Bandarra N M, Thorsdottir I
Landspitali-University Hospital & Faculty of Food Science and Nutrition, Eiriksgata 29, 101, Reykjavik, Iceland.
Diabetologia. 2008 Jul;51(7):1261-8. doi: 10.1007/s00125-008-1035-7. Epub 2008 May 20.
AIMS/HYPOTHESIS: Epidemiological research indicates that long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) improve insulin resistance. The aim of this study was to investigate the effects of seafood consumption on insulin resistance in overweight participants during energy restriction.
In this 8 week dietary intervention, 324 participants (20-40 years, BMI 27.5-32.5 kg/m(2), from Iceland, Spain and Ireland) were randomised by computer to one of four energy-restricted diets (-30E%) of identical macronutrient composition but different LC n-3 PUFA content: control (n = 80; no seafood; single-blinded); lean fish (n = 80; 150 g cod, three times/week); fatty fish (n = 84; 150 g salmon, three times/week); (4) fish oil (n = 80; daily docosahexaenoic/eicosapentaenoic acid capsules, no other seafood; single-blinded). Fasting glucose, insulin, adiponectin, plasma triacylglycerol and fatty acids in erythrocyte membrane were measured at baseline and endpoint. Insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). Linear models with fixed effects and covariates were used to investigate the effects of seafood consumption on fasting insulin and HOMA-IR at endpoint in comparison with the control group.
Of the participants, 278 (86%) completed the intervention. Fish oil intake was a significant predictor of fasting insulin and insulin resistance after 8 weeks, and this finding remained significant even after including weight loss, triacylglycerol reduction, increased LC n-3 PUFA in membranes or adiponectin changes as covariates in the statistical analysis. Weight loss was also a significant predictor of improvements.
CONCLUSIONS/INTERPRETATION: LC n-3 PUFA consumption during energy reduction exerts positive effects on insulin resistance in young overweight individuals, independently from changes in body weight, triacylglycerol, erythrocyte membrane or adiponectin.
ClinicalTrials.gov NCT00315770.
目的/假设：流行病学研究表明，长链n-3多不饱和脂肪酸（LC n-3 PUFA）可改善胰岛素抵抗。本研究旨在探讨能量限制期间食用海鲜对超重参与者胰岛素抵抗的影响。
在这项为期8周的饮食干预中，324名参与者（年龄20 - 40岁，BMI 27.5 - 32.5 kg/m²，来自冰岛、西班牙和爱尔兰）通过计算机随机分配到四种能量限制饮食（-30E%）中的一种，这四种饮食的宏量营养素组成相同，但LC n-3 PUFA含量不同：对照组（n = 80；不食用海鲜；单盲）；瘦鱼组（n = 80；每周三次，每次150克鳕鱼）；肥鱼组（n = 84；每周三次，每次150克三文鱼）；（4）鱼油组（n = 80；每日服用二十二碳六烯酸/二十碳五烯酸胶囊，不食用其他海鲜；单盲）。在基线和终点测量空腹血糖、胰岛素、脂联素、血浆甘油三酯和红细胞膜脂肪酸。使用胰岛素抵抗稳态模型评估（HOMA-IR）计算胰岛素抵抗。使用具有固定效应和协变量的线性模型，研究与对照组相比，食用海鲜对终点时空腹胰岛素和HOMA-IR的影响。
参与者中有278人（86%）完成了干预。8周后，鱼油摄入量是空腹胰岛素和胰岛素抵抗的显著预测指标，即使在统计分析中纳入体重减轻、甘油三酯降低、膜中LC n-3 PUFA增加或脂联素变化作为协变量后，这一发现仍然显著。体重减轻也是改善情况的显著预测指标。
结论/解读：在能量减少期间食用LC n-3 PUFA对年轻超重个体的胰岛素抵抗有积极影响，独立于体重、甘油三酯、红细胞膜或脂联素的变化。
ClinicalTrials.gov NCT00315770。
