Chromium effects on glucose tolerance and insulin sensitivity in persons at risk for diabetes mellitus.
OBJECTIVE
To investigate the effects of daily chromium picolinate supplementation on serum measures of glucose tolerance and insulin sensitivity in patients at high risk for type 2 diabetes mellitus.


METHODS
We conducted a randomized, double-blind, placebo-controlled, modified cross-over clinical trial with 6-month sequences of intervention and placebo followed by a 6-month postintervention assessment. Adult patients with impaired fasting glucose, impaired glucose tolerance, or metabolic syndrome were enrolled. Participants received 6-month sequences of chromium picolinate or placebo at 1 of 2 dosages (500 or 1000 mcg daily). Primary outcome measures were change in fasting plasma glucose, 2-hour plasma glucose during oral glucose tolerance testing, fasting and 2-hour insulin, and homeostasis model assessment of insulin resistance (HOMA-IR). Secondary outcomes included anthropometric measures, blood pressure, endothelial function, hemoglobin A1c, lipids, and urinary microalbumin.


RESULTS
Fifty-nine participants were enrolled. No changes were seen in glucose level, insulin level, or HOMA-IR (all P>.05) after 6 months of chromium at either dosage level (500 mcg or 1000 mcg daily) when compared with placebo. None of the secondary outcomes improved with either chromium dosage compared with placebo (P>.05).


CONCLUSIONS
Chromium supplementation does not appear to ameliorate insulin resistance or impaired glucose metabolism in patients at risk for type 2 diabetes and thus is unlikely to attenuate diabetes risk.
Ali
Ather
A
Prevention Research Center, Yale University School of Medicine, Derby, Connecticut 06418, USA.
Ma
Yingying
Y
Reynolds
Jesse
J
Wise
John Pierce
JP
Inzucchi
Silvio E
SE
Katz
David L
DL
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects*; D002857:Chromium / Q000627:therapeutic use*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D004311:Double-Blind Method; D005260:Female; D018149:Glucose Intolerance / Q000188:drug therapy*; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D002857:Chromium