Lee SoJung, Hudson Robert, Kilpatrick Katherine, Graham Terry E, Ross Robert
School of Physical and Health Education, Queen's University, Kingston, Ontario, Canada, K7L 3N6.
Diabetes Care. 2005 Mar;28(3):566-72. doi: 10.2337/diacare.28.3.566.
We investigated the effect of caffeine ingestion on insulin sensitivity in sedentary lean men (n = 8) and obese men with (n = 7) and without (n = 8) type 2 diabetes. We also examined whether chronic exercise influences the relationship between caffeine and insulin sensitivity in these individuals.
Subjects underwent two hyperinsulinemic-euglycemic clamp procedures, caffeine (5 mg/kg body wt) and placebo, in a double-blind, randomized manner before and after a 3-month aerobic exercise program. Body composition was measured by magnetic resonance imaging.
At baseline, caffeine ingestion was associated with a significant reduction (P < 0.05) in insulin sensitivity by a similar magnitude in the lean (33%), obese (33%), and type 2 diabetic (37%) groups in comparison with placebo. After exercise training, caffeine ingestion was still associated with a reduction (P < 0.05) in insulin sensitivity by a similar magnitude in the lean (23%), obese (26%), and type 2 diabetic (36%) groups in comparison with placebo. Exercise was not associated with a significant increase in insulin sensitivity in either the caffeine or placebo trials, independent of group (P > 0.10).
Caffeine consumption is associated with a substantial reduction in insulin-mediated glucose uptake independent of obesity, type 2 diabetes, and chronic exercise.
我们研究了摄入咖啡因对久坐不动的瘦男性（n = 8）以及患有（n = 7）和未患（n = 8）2型糖尿病的肥胖男性胰岛素敏感性的影响。我们还研究了长期运动是否会影响这些个体中咖啡因与胰岛素敏感性之间的关系。
受试者在为期3个月的有氧运动计划前后，以双盲、随机的方式接受两次高胰岛素-正常血糖钳夹试验，分别摄入咖啡因（5 mg/kg体重）和安慰剂。通过磁共振成像测量身体成分。
在基线时，与安慰剂相比，摄入咖啡因后，瘦人群组（33%）、肥胖人群组（33%）和2型糖尿病患者组（37%）的胰岛素敏感性均显著降低（P < 0.05），降低幅度相似。运动训练后，与安慰剂相比，摄入咖啡因后，瘦人群组（23%）、肥胖人群组（26%）和2型糖尿病患者组（36%）的胰岛素敏感性仍显著降低（P < 0.05），降低幅度相似。在咖啡因或安慰剂试验中，无论组别如何，运动均未使胰岛素敏感性显著增加（P > 0.10）。
摄入咖啡因与胰岛素介导的葡萄糖摄取大幅降低有关，且不受肥胖、2型糖尿病和长期运动的影响。
