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Written by By Dan Gwartney, MD
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Wednesday, 21 January 2009 |
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Page 6 of 6
SIDEBAR
Key Facts Relating To IL6 During Exercise And Fat Loss:
• Resting IL6 comes from the visceral fat and is a sign of ongoing inflammation.
• Resting IL6 causes insulin resistance in the liver and can promote dangerous health conditions.
• Resting IL6 levels are three times higher in obese (BMI>30) compared to normal-weight people, four times higher in the super-obese (BMI>40).
• In addition to inflammatory cells and fat cells, skeletal muscle is a major source of IL6.
• A lifestyle that includes exercise lowers resting IL6.
• During exercise, muscle contractions lead to the production/release of IL6, increasing blood levels nearly 100-fold. This is rapidly cleared once exercise ends.
• Niacin and high-carbohydrate drinks during exercise lower the IL6 response to exercise in muscle.
• A low-carbohydrate diet may allow for a greater IL6 response by keeping muscle glycogen levels low.
• Supplementation with Antioxidants may lower IL6 production during exercise.
• Exercise-related IL6 acts as an anti-insulin at the liver and fat cell to increase energy substrate (fat and sugar) to the working muscle. This leads to fat loss.
• Exercise-related IL6 works with insulin at the working muscle to increase sugar intake from the blood.
• Exercise-related IL6 increases calorie burning in muscle and fatty acid oxidation specifically.
• Exercise-related IL6 promotes the recruitment of satellite cells into muscle cells to promote muscle hypertrophy.
• Low testosterone is associated with high IL6, aging and chronic diseases.
References:
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3. Senn JJ, Klover PJ, et al. Interleukin-6 induces cellular insulin resistance in hepatocytes. Diabetes, 2002;51:3391-9.
4. Rotter V, Nagaev I, et al. Interleukin-6 (IL-6) induces insulin resistance in 3T3-L1 adipocytes and is, like IL-8 and tumor necrosis factor-alpha, overexpressed in human fat cells from insulin-resistant subjects. J Biol Chem, 2003;278:45777-84.
5. Senn JJ, Klover PJ, et al. Suppressor of cytokine signaling-3 (SOCS-3), a potential mediator of interleukin-6-dependent insulin resistance in hepatocytes. J Biol Chem, 2003;278:13740-6.
6. Carey AL, Steinberg GR, et al. Interleukin-6 increases insulin-stimulated glucose disposal in humans and glucose uptake and fatty acid oxidation in vitro via AMP-activated protein kinase. Diabetes, 2006;55:2688-97.
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10. Pedersen BK, Febbraio MA. Point: Interleukin-6 does have a beneficial role in insulin sensitivity and glucose homeostasis. J Appl Physiol, 2007;102;814-9.
11. Mooney RA. Counterpoint: Interleukin-6 does not have a beneficial role in insulin sensitivity and glucose homeostasis. J Appl Physiol, 2007;102:814-9.
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13. Hamdy O, Porramatikul S, et al. Metabolic obesity: the paradox between visceral and subcutaneous fat. Curr Diabet Rev, 2006;2:367-73.
14. Kim JH, Kim JE, et al. Regulation of interleukin-6-induced hepatic insulin resistance by mammalian target of rapamycin through the STAT3-SOCS3 pathway. J Biol Chem, 2008;283:708-15.
15. Barnett A. Exenatide. Expert Opin Pharmacother, 2007;8:2593-608.
16. Pedersen BK, Steensberg A, et al. Searching for the exercise factor: is IL-6 a candidate? J Muscle Res Cell Motil, 2003;24:113-9.
17. Pedersen BK, Akerstrom TC, et al. Role of myokines in exercise and metabolism. J Appl Physiol, 2007;103:1093-8.
18. Huang S, Czech MP. The GLUT4 glucose transporter. Cell Metab, 2007;5:237-52.
19. Kim HJ, Higashimori T, et al. Differential effects of interleukin-6 and -10 on skeletal muscle and liver insulin action in vivo. Diabetes, 2004;53:1060-67.
20. Carey AL, Steinberg GR, et al. IL-6 increases insulin stimulated glucose disposal in humans and glucose uptake and fatty acid oxidation in vitro via AMPK. Diabetes, 2006;55:2688-97.
21. Petersen EW, Carey AL, et al. Acute IL-6 treatment increases fatty acid turnover in elderly humans in vivo and in tissue culture in vitro: evidence that IL-6 acts independently of lipolytic hormones. Am J Physiol Endocrinol Metab, 2005;288:E155-62.
22. Jessen N, Goodyear LJ. Contraction signaling to glucose transport in skeletal muscle. J Appl Physiol, 2005;99:330-7.
23. Hoene M, Weigert C. The role of interleukin-6 in insulin resistance, body fat distribution and energy balance. Obes Rev, 2008;9:20-9.
24. Serrano AL, Baeza-Raja B, et al. Interleukin-6 is an essential regulator of satellite cell-mediated skeletal muscle hypertrophy. Cell Metabolism, 2008;7:33-44.
25. Kapoor D, Clarke S, et al. The effect of testosterone replacement therapy on adipocytokines and C-reactive protein in hypogonadal men with type 2 diabetes. Eur J Endocrinol, 2007;156:595-602.
26. Maggio M, Guralnik JM, et al. Interleukin-6 in aging and chronic disease: a magnificent pathway. J Gerontol, 2006;61A:575-84.
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