Lim Soo, Choi Sung Hee, Jeong In-Kyong, Kim Jae Hyeon, Moon Min Kyong, Park Kyong Soo, Lee Hong Kyu, Kim Young-Bum, Jang Hak Chul
Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 28 Yongon-dong Chongno-gu, Seoul, Korea.
J Clin Endocrinol Metab. 2008 Jun;93(6):2263-8. doi: 10.1210/jc.2007-2028. Epub 2008 Mar 11.
Exercise training enhances insulin sensitivity. Changes in retinol-binding protein-4 (RBP4) and adiponectin levels are linked to insulin resistance.
We tested whether the insulin-sensitizing effect of exercise is associated with age-related changes in circulating RBP4 and adiponectin levels in women.
DESIGN, SUBJECTS, AND INTERVENTION: We studied 36 healthy young (22.4 +/- 2.8 yr) and 38 middle-aged (59.8 +/- 5.9 yr) women. All subjects performed 60 min of aerobic exercise three times per week for 10 wk at about 70% maximal exercise capacity.
After a 10-wk training program, maximal exercise capacity was significantly increased in both young and middle-aged women, suggesting increased oxidative capacity. Insulin sensitivity was also improved, as indicated by decreases in plasma insulin levels and homeostasis model assessment for insulin resistance index. Serum adiponectin and RBP4 concentrations were increased and decreased more in older than younger women, respectively (P < 0.01). Concurrently, circulating transthyretin levels were also decreased in older subjects in response to exercise training. The older women showed higher correlations between changes in adiponectin or RBP4 levels and obesity indices or metabolic parameters than the younger group. When subjects showing increasing adiponectin or decreasing RBP4 levels were classified as responders, there were higher correlations between these changes in responders than in nonresponders.
We conclude that the mechanism for the insulin-sensitizing effects of exercise could involve increased adiponectin and reduced RBP4 levels in exercise-trained women. These data suggest that alterations in circulating RBP4 and adiponectin levels could play an important role in regulating insulin sensitivity.
运动训练可增强胰岛素敏感性。视黄醇结合蛋白4（RBP4）和脂联素水平的变化与胰岛素抵抗有关。
我们测试了运动的胰岛素增敏作用是否与女性循环中RBP4和脂联素水平的年龄相关变化有关。
设计、研究对象与干预措施：我们研究了36名健康年轻女性（22.4±2.8岁）和38名中年女性（59.8±5.9岁）。所有研究对象每周进行3次60分钟的有氧运动，持续10周，运动强度约为最大运动能力的70%。
经过10周的训练计划，年轻和中年女性的最大运动能力均显著提高，表明氧化能力增强。胰岛素敏感性也得到改善，表现为血浆胰岛素水平降低和胰岛素抵抗指数的稳态模型评估值降低。老年女性血清脂联素浓度升高幅度大于年轻女性，而血清RBP4浓度降低幅度大于年轻女性（P<0.01）。同时，老年受试者运动训练后循环甲状腺素转运蛋白水平也降低。老年女性脂联素或RBP4水平变化与肥胖指数或代谢参数之间的相关性高于年轻组。当将脂联素水平升高或RBP4水平降低的受试者分类为反应者时，反应者的这些变化之间的相关性高于无反应者。
我们得出结论，运动的胰岛素增敏作用机制可能涉及运动训练女性脂联素增加和RBP4水平降低。这些数据表明，循环中RBP4和脂联素水平的改变可能在调节胰岛素敏感性中起重要作用。
