Recent evidence suggests that glucose intolerance even in the absence of hyperglycemia is an independent risk factor for atherosclerosis [Saydamn et al., 2007]. Chromium supplementation may make an impact on this condition.
A randomized double-blind study of fasting insulin levels in healthy young adults (n = 26) found that 90 days of chromium (III)-nicotinate containing 220 mcg of chromium produced a significant decrease in immunoreactive insulin in those patients with initial fasting levels greater than 35 pmol/L [West et al., 2005]. Improvements in insulin sensitivity were seen in another small double-blind trial [Hudrat et al., 2007].
A double-blind crossover study of 67 healthy individuals found that in people with abnormal glucose tolerance chromium normalized glucose responses [Henderson et al., 2003]. This occurred whether the abnormality was elevated or depressed serum glucose. Chromium had no effect on participants with normal glucose tolerance.
However, a study of 26 elderly subjects with impaired glucose tolerance randomly treated with either chromium-rich yeast (160 mcg CR/day) or a placebo showed no effect on glucose tolerance [Hunk, 2002].