Effect of Chromium Supplementation on Glucose Metabolism and Lipids

A systematic review of randomized controlled trials

  1. Ethan M. Balk, MD, MPH1,
  2. Athina Tatsioni, MD1,
  3. Alice H. Lichtenstein, DSC2,
  4. Joseph Lau, MD1 and
  5. Anastassios G. Pittas, MD, MSC3
  1. 1Institute for Clinical Research and Health Policy Studies, Tufts-New England Medical Center, Boston, Massachusetts
  2. 2Clinical Nutrition Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
  3. 3Division of Endocrinology, Diabetes and Metabolism, Tufts-New England Medical Center, Boston, Massachusetts
  1. Address correspondence and reprint requests to Ethan Balk, Institute for Clinical Research and Health Policy Studies, Tufts-New England Medical Center, 750 Washington St., NEMC #63, Boston, MA 02111. E-mail: ebalk{at}tufts-nemc.org

Abstract

OBJECTIVE—A systematic review of the effect of chromium supplementation on glucose metabolism and lipid levels.

RESEARCH DESIGN AND METHODS—A literature search was conducted in MEDLINE and the Commonwealth Agricultural Bureau. Eligible studies were English language randomized controlled trials of chromium supplement intake ≥3 weeks, with ≥10 participants receiving chromium. All trials with glucose metabolism outcomes and trials of individuals with diabetes or glucose intolerance for lipid outcomes were included. Meta-analyses were performed as appropriate.

RESULTS—Forty-one studies met criteria, almost half of which were of poor quality. Among participants with type 2 diabetes, chromium supplementation improved glycosylated hemoglobin levels by −0.6% (95% CI −0.9 to −0.2) and fasting glucose by −1.0 mmol/l (−1.4 to −0.5) but not lipids. There was no benefit in individuals without diabetes. There were some indications of dose effect and differences among chromium formulations. Larger effects were more commonly observed in poor-quality studies. The evidence was limited by poor study quality, heterogeneity in methodology and results, and a lack of consensus on assessment of chromium status.

CONCLUSIONS—No significant effect of chromium on lipid or glucose metabolism was found in people without diabetes. Chromium supplementation significantly improved glycemia among patients with diabetes. However, future studies that address the limitations in the current evidence are needed before definitive claims can be made about the effect of chromium supplementation.

Footnotes

  • Published ahead of print at http://care.diabetesjournals.org on 22 May 2007. DOI: 10.2337/dc06-0996.

    Additional information for this article can be found in an online appendix at http://dx.doi.org/10.2337/dc06-0996.

    A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

    • Accepted May 14, 2007.
    • Received May 15, 2006.
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This Article

  1. Diabetes Care vol. 30 no. 8 2154-2163
  1. Online-Only Appendix
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