Huerta A E, Prieto-Hontoria P L, Fernández-Galilea M, Sáinz N, Cuervo M, Martínez J A, Moreno-Aliaga M J
Department of Nutrition, Food Science and Physiology, University of Navarra, Pamplona, Spain.
J Physiol Biochem. 2015 Sep;71(3):547-58. doi: 10.1007/s13105-015-0400-5. Epub 2015 Mar 28.
Irisin is a myokine/adipokine with potential role in obesity and diabetes. The objectives of the present study were to analyse the relationship between irisin and glucose metabolism at baseline and during an oral glucose tolerance test (OGTT) and to determine the effects of eicosapentaenoic acid (EPA) and/or α-lipoic acid treatment on irisin production in cultured human adipocytes and in vivo in healthy overweight/obese women following a weight loss program. Seventy-three overweight/obese women followed a 30% energy-restricted diet supplemented without (control) or with EPA (1.3 g/day), α-lipoic acid (0.3 g/day) or both EPA + α-lipoic acid (1.3 + 0.3 g/day) during 10 weeks. An OGTT was performed at baseline. Moreover, human adipocytes were treated with EPA (100-200 μM) or α-lipoic acid (100-250 μM) during 24 h. At baseline plasma, irisin circulating levels were positively associated with glucose levels; however, serum irisin concentrations were not affected by the increment in blood glucose or insulin during the OGTT. Treatment with α-lipoic acid (250 μM) upregulated Fndc5 messenger RNA (mRNA) and irisin secretion in cultured adipocytes. In overweight/obese women, irisin circulating levels decreased significantly after weight loss in all groups, while no additional differences were induced by EPA or α-lipoic acid supplementation. Moreover, plasma irisin levels were positively associated with higher glucose concentrations at beginning and at endpoint of the study. The data from the OGTT suggest that glucose is not a direct contributing factor of irisin release. The higher irisin levels observed in overweight/obese conditions could be a protective response of organism to early glucose impairments.
鸢尾素是一种肌动蛋白/脂肪因子，在肥胖和糖尿病中具有潜在作用。本研究的目的是分析基线时以及口服葡萄糖耐量试验（OGTT）期间鸢尾素与葡萄糖代谢之间的关系，并确定二十碳五烯酸（EPA）和/或α-硫辛酸处理对培养的人脂肪细胞以及健康超重/肥胖女性在减肥计划后的体内鸢尾素产生的影响。73名超重/肥胖女性遵循了一项为期10周的30%能量限制饮食，分为不添加任何物质（对照组）、添加EPA（1.3克/天）、α-硫辛酸（0.3克/天）或两者同时添加（1.3 + 0.3克/天）。在基线时进行了OGTT。此外，人脂肪细胞用EPA（100 - 200微摩尔）或α-硫辛酸（100 - 250微摩尔）处理24小时。在基线血浆中，鸢尾素循环水平与葡萄糖水平呈正相关；然而，OGTT期间血糖或胰岛素的升高并未影响血清鸢尾素浓度。用α-硫辛酸（250微摩尔）处理可上调培养脂肪细胞中Fndc5信使核糖核酸（mRNA）和鸢尾素分泌。在超重/肥胖女性中，所有组减肥后鸢尾素循环水平均显著下降，而EPA或α-硫辛酸补充并未引起额外差异。此外，在研究开始和结束时，血浆鸢尾素水平与较高的葡萄糖浓度呈正相关。OGTT的数据表明，葡萄糖不是鸢尾素释放的直接促成因素。在超重/肥胖状态下观察到的较高鸢尾素水平可能是机体对早期葡萄糖损伤的一种保护反应。
