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Chromium Supplementation Does Not Improve Glucose Tolerance, Insulin Sensitivity, or Lipid Profile: A Randomized, Placebo-Controlled, Double-Blind Trial of Supplementation in Subjects With Impaired Glucose Tolerance

Response to Komorowski and Juturu

¹ Department of Endocrinology, Royal North Shore Hospital, St. Leonards, Sydney, Australia
² Cellular and Molecular Physiology, Joslin Diabetes Center, Boston, Massachusetts
³ Department of Diabetes and Endocrinology, Western Sydney Area Health Service, Westmead and Nepean Hospitals, Sydney, Australia
⁴ Pacific Laboratory Medical Services, Royal North Shore Hospital, Sydney, Australia

Address correspondence to Jenny Gunton, c/o Kahn Laboratory, Level 6, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215. E-mail: jenny.gunton{at}joslin.harvard.edu

We thank Komorowski and Juturu (1) for their interest in our study, and we agree that it is possible that higher doses of chromium may show some effects. The subjects in this study received 100 µg of elemental chromium daily, administered as 800 µg of chromium picolinate, for 3 months. The small increase in serum chromium in the active group is probably appropriate for this dose. It is worth noting that significant uncertainty remains regarding how best to measure whole-body chromium status, as there are no well-defined outcomes to allow determination of a therapeutic range. This unfortunately includes assaying of serum.

The Australian Therapeutic Goods Administration daily dose recommendation was adopted in 2004 and is based on concerns about the safety of higher doses as raised by the Complementary Medicines Evaluation Committee (2), including two reports of renal failure (3,4). Our study commenced before 2003 and was scientifically reviewed by our local ethics committee.

We do not agree that the results of the study conflict with the literature. Studies of chromium supplementation in nondiabetic subjects and people with normal glucose tolerance, insulin resistance, and/or impaired glucose tolerance (IGT) have not produced any consistent benefits, as reviewed by Cefalu et al. (5), Yeh et al. (6), Althuis et al. (7), and Gunton et al. (8). In contrast, some studies in subjects with diabetes have shown significant benefits (5,8), and further studies in this group will be of great interest.

Our study was conducted in people diagnosed with impaired glucose tolerance according to the American Diabetes Association criteria. Efficacy was also evaluated using area under the curve during glucose tolerance testing, but this was also nonsignificant (data not shown). We feel that at this dose, chromium picolinate supplementation in subjects with impaired glucose tolerance is ineffective.

We note that Komorowski and Juturu are affiliated with Nutrition 21, Inc., which markets chromium picolinate.

References

1. Komorowski J, Juturu V: Chromium supplementation does not improve glucose tolerance, insulin sensitivity, or lipid profile: a randomized, placebo-controlled, double-blind trial of supplementation in subjects with impaired glucose tolerance: response to Gunton et al. (Letter). Diabetes Care 28:1841–1842, 2005[Free Full Text]
   
2. Complementary Medicines Evaluation Committee (CMEC), meeting 41, 1 August 2003, public recommendation summary [summary online]. Available at http://www.tga.gov.au/docs/html/cmec/cmecdr41.htm. Accessed April 2005
   
3. Wasser WG, Feldman NS: Chronic renal failure after ingestion of over-the-counter chromium picolinate. Ann Intern Med 126:410, 1997[Free Full Text]
   
4. Cerulli DW, Grabe I, Gauthier M, Malone and McGoldrick MD: Chromium picolinate toxicity. Ann Pharmacother 32:428–431, 1998[Abstract]
   
5. Cefalu WT, Hu FB: Role of chromium in human health and in diabetes. Diabetes Care 27:2741–2751, 2004[Free Full Text]
   
6. Yeh GY, Eisenberg DM, Kaptchuk TJ, Phillips RS: Systematic review of herbs and dietary supplements for glycemic control in diabetes (Review Article). Diabetes Care 26:1277–1294, 2003[Abstract/Free Full Text]
   
7. Althuis MD, Jordan NE, Ludington EA, Wittes JT: Glucose and insulin responses to dietary chromium supplements: a meta-analysis. Am J Clin Nutr 76:148–155, 2002[Abstract/Free Full Text]
   
8. Gunton JE, Hams G, Hitchman R, McElduff A: Serum chromium does not predict glucose tolerance in late pregnancy. Am J Clin Nutr 73:99–104, 2001[Abstract/Free Full Text]
   

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This Article Extract Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Gunton, J. E. Articles by McElduff, A. Search for Related Content PubMed Articles by Gunton, J. E. Articles by McElduff, A. Social Bookmarking                What's this?