BACKGROUND: The role of chromium in human nutrition was first reported in 1977 on a patient on total parenteral nutrition manifesting with neuropathy and impaired glucose tolerance attributed to chromium deficiency. After correction, nerve conduction and glucose tolerance tests normalized. Chromium is postulated to act as a cofactor for insulin action by enhancing insulin receptor phosphorylation and stimulating insulin receptor tyrosine kinase.
OBJECTIVE: To compare the effect of chromium picolinate versus placebo on glycated hemoglobin (HbA1C), fasting blood sugar (FBS), 2-hours postprandial blood sugar (2HPPBS), fasting insulin (FI) and lipid profile among T2DM patients.
METHODS: Literature search in Medicine, Cochrane and Herdin was made using terms such as chromium, chromium picolinate intake of >= 3 months among T2DM patients. Two reviewers independently screened abstracts and full articles. Results were plotted using Revman 4.2.
RESULTS: Thirty four trials were found and six trials were included in the meta-analysis. The pooled data for 467 patients with T2DM reported lowering of HbA1c -0.34% (CI -0.45, 0.24 p0.06); FBS -16.6 mg/dl (CI -18.9, -14.41 p 0.30); 2HPPBS -17.33 mg/dL (CI -20.21, -18..81 p <0.01) and FI -19.51 mg/dL (CI -20.21, -18.81 p<0.01). Chromium picolinate has no effect on lipids.
CONCLUSION: Chromium picolinate lowers HbA1c, FBS, 2HPPBS and FI moderately but it has no effect on lipids, However, the short duration of studies, variable quality and large heterogeneity across these data limits the strength of our conclusion, hence further studies are recommended.