Not provided
Not provided
Not provided
Not provided
Not provided
Lack of successful recruiting, budget cuts, and potential study flaws.
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Moderate exercise is thought to be one of the best known means to improve how insulin works in people. Taking vitamin C and vitamin E is also thought to have the same effect. This study is being done to see if taking vitamin C and vitamin E improves or hinders how insulin works when people do not exercise and when they do exercise.
The objective of the study is to determine in humans whether anti-oxidant supplementation with ascorbate (vitamin C) or R,R,R-α-tocopherol acetate (vitamin E) improves insulin sensitivity in the untrained state but blocks exercise-induced increases in insulin sensitivity and other adaptations to exercise. The results will provide new information on the roles of anti-oxidant supplementation in modifying insulin sensitivity, and will inform guidelines for anti-oxidant supplementation as an adjunct to exercise.
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Vitamin E and Vitamin C | Active Comparator | 4 weeks with Vitamin E and Vitamin C supplementation with no exercise and 4 weeks of supplementation with prescribed exercise. |
|
| Placebo | No Intervention | Placebos instead of the Vitamin E and Vitamin C supplements |
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Vitamin E and Vitamin C | Dietary Supplement | Vitamin E 400 iu/dose daily times 56 days Vitamin C 500 mg/dose twice daily times 56 days |
|
| Measure | Description | Time Frame |
|---|---|---|
| (1) Blood glucose and insulin following glucose challenge in non-exercising and exercising people (BMI 27 to 35) taking anti-oxidants (vitamin E and vitamin C) or placebo. | Individuals will be in placebo and vitamin supplemented groups in a cross-over design. A total of 6 oral glucose tolerance tests will be performed per subject in the study. | 28 weeks |
| Measure | Description | Time Frame |
|---|---|---|
| (1) Resting metabolic rate, body composition, plasma oxidative stress, plasma vitamin E and vitamin C levels in non-exercising and exercising people (BMI 27 to 35) taking anti-oxidants (vitamin E and vitamin C) or placebo. | 28 weeks | |
| (2) Fitness measures (heart rate, exercise work, VO2, VCO2, blood lactate) in non-exercising and exercising people (BMI 27 to 35) taking anti-oxidants (vitamin E and vitamin C) or placebo. |
Not provided
Inclusion Criteria:
Exclusion Criteria:
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Matthew Picklo, PhD | Agriculture Research Service, United States Department of Agriculture, Grand Forks Human Nutrition Research Center | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Grand Forks Human Nutrition Research Center | Grand Forks | North Dakota | 58201 | United States |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 11832527 | Background | Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, Nathan DM; Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002 Feb 7;346(6):393-403. doi: 10.1056/NEJMoa012512. | |
| 15817846 | Background |
Not provided
Not provided
Not provided
| ID | Term |
|---|---|
| D009043 | Motor Activity |
| ID | Term |
|---|---|
| D001519 | Behavior |
Not provided
Not provided
| ID | Term |
|---|---|
| D014810 | Vitamin E |
| D001205 | Ascorbic Acid |
| ID | Term |
|---|---|
| D001578 | Benzopyrans |
| D011714 | Pyrans |
| D006573 | Heterocyclic Compounds, 1-Ring |
| D006571 | Heterocyclic Compounds |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| 28 weeks |
| Hathcock JN, Azzi A, Blumberg J, Bray T, Dickinson A, Frei B, Jialal I, Johnston CS, Kelly FJ, Kraemer K, Packer L, Parthasarathy S, Sies H, Traber MG. Vitamins E and C are safe across a broad range of intakes. Am J Clin Nutr. 2005 Apr;81(4):736-45. doi: 10.1093/ajcn/81.4.736. |
| 18191645 | Background | Devaraj S, Leonard S, Traber MG, Jialal I. Gamma-tocopherol supplementation alone and in combination with alpha-tocopherol alters biomarkers of oxidative stress and inflammation in subjects with metabolic syndrome. Free Radic Biol Med. 2008 Mar 15;44(6):1203-8. doi: 10.1016/j.freeradbiomed.2007.12.018. Epub 2007 Dec 23. |
| 19154960 | Background | Vincent HK, Bourguignon CM, Weltman AL, Vincent KR, Barrett E, Innes KE, Taylor AG. Effects of antioxidant supplementation on insulin sensitivity, endothelial adhesion molecules, and oxidative stress in normal-weight and overweight young adults. Metabolism. 2009 Feb;58(2):254-62. doi: 10.1016/j.metabol.2008.09.022. |
| 15599400 | Background | Furukawa S, Fujita T, Shimabukuro M, Iwaki M, Yamada Y, Nakajima Y, Nakayama O, Makishima M, Matsuda M, Shimomura I. Increased oxidative stress in obesity and its impact on metabolic syndrome. J Clin Invest. 2004 Dec;114(12):1752-61. doi: 10.1172/JCI21625. |
| 19219062 | Background | Gletsu-Miller N, Hansen JM, Jones DP, Go YM, Torres WE, Ziegler TR, Lin E. Loss of total and visceral adipose tissue mass predicts decreases in oxidative stress after weight-loss surgery. Obesity (Silver Spring). 2009 Mar;17(3):439-46. doi: 10.1038/oby.2008.542. Epub 2008 Dec 11. |
| 18803936 | Background | Manning PJ, Sutherland WH, Walker RJ, de Jong SA, Berry EA. The effect of glucose ingestion on inflammation and oxidative stress in obese individuals. Metabolism. 2008 Oct;57(10):1345-9. doi: 10.1016/j.metabol.2008.04.020. |
| 18541328 | Background | Manning PJ, Sutherland WH, Walker RJ, Williams SM, de Jong SA, Berry EA. The effect of rosiglitazone on oxidative stress and insulin resistance in overweight individuals. Diabetes Res Clin Pract. 2008 Aug;81(2):209-15. doi: 10.1016/j.diabres.2008.04.015. Epub 2008 Jun 9. |
| 17299112 | Background | Sutherland WH, Manning PJ, Walker RJ, de Jong SA, Ryalls AR, Berry EA. Vitamin E supplementation and plasma 8-isoprostane and adiponectin in overweight subjects. Obesity (Silver Spring). 2007 Feb;15(2):386-91. doi: 10.1038/oby.2007.546. |
| 15333479 | Background | Manning PJ, Sutherland WH, Walker RJ, Williams SM, De Jong SA, Ryalls AR, Berry EA. Effect of high-dose vitamin E on insulin resistance and associated parameters in overweight subjects. Diabetes Care. 2004 Sep;27(9):2166-71. doi: 10.2337/diacare.27.9.2166. |
| 11147782 | Background | Perticone F, Ceravolo R, Candigliota M, Ventura G, Iacopino S, Sinopoli F, Mattioli PL. Obesity and body fat distribution induce endothelial dysfunction by oxidative stress: protective effect of vitamin C. Diabetes. 2001 Jan;50(1):159-65. doi: 10.2337/diabetes.50.1.159. |
| 16126809 | Background | Chen H, Karne RJ, Hall G, Campia U, Panza JA, Cannon RO 3rd, Wang Y, Katz A, Levine M, Quon MJ. High-dose oral vitamin C partially replenishes vitamin C levels in patients with Type 2 diabetes and low vitamin C levels but does not improve endothelial dysfunction or insulin resistance. Am J Physiol Heart Circ Physiol. 2006 Jan;290(1):H137-45. doi: 10.1152/ajpheart.00768.2005. Epub 2005 Aug 26. |
| 18978171 | Background | Rizzo MR, Abbatecola AM, Barbieri M, Vietri MT, Cioffi M, Grella R, Molinari A, Forsey R, Powell J, Paolisso G. Evidence for anti-inflammatory effects of combined administration of vitamin E and C in older persons with impaired fasting glucose: impact on insulin action. J Am Coll Nutr. 2008 Aug;27(4):505-11. doi: 10.1080/07315724.2008.10719732. |
| 12626489 | Background | Bailey DM, Davies B, Young IS, Jackson MJ, Davison GW, Isaacson R, Richardson RS. EPR spectroscopic detection of free radical outflow from an isolated muscle bed in exercising humans. J Appl Physiol (1985). 2003 May;94(5):1714-8. doi: 10.1152/japplphysiol.01024.2002. Epub 2003 Mar 7. |
| 17364944 | Background | Bailey DM, Lawrenson L, McEneny J, Young IS, James PE, Jackson SK, Henry RR, Mathieu-Costello O, McCord JM, Richardson RS. Electron paramagnetic spectroscopic evidence of exercise-induced free radical accumulation in human skeletal muscle. Free Radic Res. 2007 Feb;41(2):182-90. doi: 10.1080/10715760601028867. |
| 15155256 | Background | Bailey DM, Young IS, McEneny J, Lawrenson L, Kim J, Barden J, Richardson RS. Regulation of free radical outflow from an isolated muscle bed in exercising humans. Am J Physiol Heart Circ Physiol. 2004 Oct;287(4):H1689-99. doi: 10.1152/ajpheart.00148.2004. Epub 2004 May 20. |
| 11585710 | Background | Mastaloudis A, Leonard SW, Traber MG. Oxidative stress in athletes during extreme endurance exercise. Free Radic Biol Med. 2001 Oct 1;31(7):911-22. doi: 10.1016/s0891-5849(01)00667-0. |
| 15110397 | Background | Mastaloudis A, Morrow JD, Hopkins DW, Devaraj S, Traber MG. Antioxidant supplementation prevents exercise-induced lipid peroxidation, but not inflammation, in ultramarathon runners. Free Radic Biol Med. 2004 May 15;36(10):1329-41. doi: 10.1016/j.freeradbiomed.2004.02.069. |
| 16394956 | Background | Mastaloudis A, Traber MG, Carstensen K, Widrick JJ. Antioxidants did not prevent muscle damage in response to an ultramarathon run. Med Sci Sports Exerc. 2006 Jan;38(1):72-80. doi: 10.1249/01.mss.0000188579.36272.f6. |
| 15059637 | Background | Mastaloudis A, Yu TW, O'Donnell RP, Frei B, Dashwood RH, Traber MG. Endurance exercise results in DNA damage as detected by the comet assay. Free Radic Biol Med. 2004 Apr 15;36(8):966-75. doi: 10.1016/j.freeradbiomed.2004.01.012. |
| 19433800 | Background | Ristow M, Zarse K, Oberbach A, Kloting N, Birringer M, Kiehntopf M, Stumvoll M, Kahn CR, Bluher M. Antioxidants prevent health-promoting effects of physical exercise in humans. Proc Natl Acad Sci U S A. 2009 May 26;106(21):8665-70. doi: 10.1073/pnas.0903485106. Epub 2009 May 11. |
| 18175748 | Background | Gomez-Cabrera MC, Domenech E, Romagnoli M, Arduini A, Borras C, Pallardo FV, Sastre J, Vina J. Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance. Am J Clin Nutr. 2008 Jan;87(1):142-9. doi: 10.1093/ajcn/87.1.142. |
| D006574 |
| Heterocyclic Compounds, 2-Ring |
| D000072471 | Heterocyclic Compounds, Fused-Ring |
| D013400 | Sugar Acids |
| D000144 | Acids, Acyclic |
| D002264 | Carboxylic Acids |
| D009930 | Organic Chemicals |
| D006880 | Hydroxy Acids |
| D002241 | Carbohydrates |