Chromium Treatment Has No Effect in Patients With Type 2 Diabetes in a Western Population

Abstract

OBJECTIVE -Chromium treatment has been reported to improve glycemic control in patients with type 2 diabetes. However, concern exists about the possible toxic effects of chromium picolinate. The aim of this study was to determine the effect of chromium treatment in the form of chromium yeast on glycemic control in a Western population of patients with type 2 diabetes who were being treated with oral hypoglycemic agents.RESEARCH DESIGN AND METHODS -In this 6-month, double-blind study, patients with moderate glycemic control, being treated with oral hypoglycemic agents, were randomly assigned to receive either a placebo or treatment with 400 g of chromium daily in the form of chromium yeast. The primary efficacy parameter was a change in A1C. Secondary end points were changes in lipid profile, BMI, blood pressure, body fat, and insulin resistance.RESULTS -No differences were found for the change in A1C between the intervention and placebo groups, nor were any differences found between the groups for the secondary end points.CONCLUSIONS -There is no evidence that chromium in the form of chromium yeast is effective in improving glycemic control in Western patients with type 2 diabetes who are taking oral hypoglycemic agents. Diabetes Care 30:1092-1096, 2007T ype 2 diabetes is a chronic, progressive illness that causes considerable morbidity and premature mortality (1,2). The worldwide prevalence of type 2 diabetes is high and is increasing steadily (3). The majority of patients are insulin resistant (4). Although these patients may be treated with well-established hypoglycemic agents, studying alternative treatment options directed toward improving insulin sensitivity is important.For many decades, we have known that chromium plays a role in glucose metabolism, and, as early as 1957, it was already being referred to as "a glucose tolerance factor" (5). In vitro and animal studies have shown that chromium improves insulin resistance (6,7). One of the intracellular proteins that influences the insulin receptor is the oligopeptide apolipoprotein low-molecular weight chromium-binding substance (Apochromomodulin) (7). This peptide has the ability to increase tyrosine kinase activity eightfold, depending on the chromium concentration (8), thus strengthening the idea that chromium plays an influential role in glucose metabolism (5).The largest study (n ϭ 180) to date investigating the effect of chromium in patients with type 2 diabetes was published by Anderson et al. (9). They found that the A1C of Chinese patients treated with 1,000 g of chromium in the form of chromium picolinate decreased almost 2 percentage points compared with a placebo group after 4 months. However, two systematic reviews that addressed the effects of chromium on glycemic control concluded that, on the basis of the currently available data, the effects of chromium on glycemic control are inconclusive (10,11). Randomized studies with results on glucose, insulin, and/or A1C were collected by Althuis et al. (10) in their review. Reasons for the inconcl...

Effect of Chromium on Glucose and Lipid Profiles in Patients with Type 2 Diabetes; A Meta-analysis Review of Randomized Trials

“…They included both type 1 and type 2 DM, gestational DM, and even steroid-induced diabetes. In the present meta-analysis, four studies showed that Cr has no significant effect on HbA1c (13,15,16,19). In two other studies (17,18), a 0.7% and 1.16% reductions in HbA1c was reported for Cr, respectively.…”

“…The summary for effect size of weighted mean differences of BMI change "∆BMI" in diabetic patients in Cr supplement therapy for six included trials comparing to Pl retrieved from five studies (13,(15)(16)(17)19) was -0.07 with 95% CI= -0.37 to 0.23 (P= 0.66, Figure 9-a). The Cochrane Q test for heterogeneity indicated that the studies are not heterogeneous (P= 0.73) and could be combined, thus the fixed effects for individual and summary of effect size for weighted mean differences was applied.…”

Chromium does not belong in the diabetes treatment arsenal: Current evidence and future perspectives

“…Chromium supplementation may be beneficial in rare cases of prolonged total parental nutrition when standard chromium supplementation is lacking [6] . Despite the lack of sufficient evidence that chromium supplementation improves glycemic control [28,29] , chromium is still widely marketed as an effective supplement for improving glycemic control in patients with type 2 diabetes.…”

“…Significant effects in the meta-analysis were only found in studies with poor methodological quality or in studies sponsored by chromium supplement producing companies. In addition, the effects of chromium supplementation were shown to be absent or non-relevant after stratifying the studies according to methodological quality, sponsor involvement, and a western vs non-western study location [6,29] . After the review written by Balk et al [28] , a second Dutch double blind trial was performed in 2008 that studied the effects of chromium on HbA1c levels in patients with type 2 diabetes [29] .…”

“…In addition, the effects of chromium supplementation were shown to be absent or non-relevant after stratifying the studies according to methodological quality, sponsor involvement, and a western vs non-western study location [6,29] . After the review written by Balk et al [28] , a second Dutch double blind trial was performed in 2008 that studied the effects of chromium on HbA1c levels in patients with type 2 diabetes [29] . After 6 mo, the effect of chromium supplementation compared to placebo on HbA1c levels was 0.24% (95%CI: -0.06% to 0.54%).…”