Lipid-lowering effect of a dietary chromium (III)—Nicotinic acid complex in male athletes

Abstract

Exercise-induced chromium (Cr) losses and marginal Cr intakes may place athletes in a suboptimal state for Cr nutritional status, possibly resulting in impaired insulin function. The purpose of this study was to assess the effects of a synthetic trivalent Cr-nicotinic acid (NA) supplement on insulin controlled variables in athletes. Thirty-four college-age male bodybuilders (BB) were randomly assigned to three groups: placebo (P), n=11; 200 μg Cr−1.8 mg NA (1X), n=12; or 800 μg Cr−7.2 mg NA (4X), n=11. Supplements were ingested daily for 8 weeks and training was controlled. Twelve hr fasting insulin, glucose, total cholesterol (TC), triglyceride, HDL-cholesterol, TC:HDL, LDL-cholesterol, and one hr post-challenge insulin and glucose values were determined at pre- and post-supplementation periods. All pre-supplementation values were within normal ranges. ANOVAs revealed two significant interactions. Mean TC in the P group increased from 139.9 to 153.4 mg/dl, yet decreased from 147.9 to 126.8 mg/dl and 159.2 to 131.3 mg/dl in the 1X and 4X groups, respectively (p<.03). Mean TC:HDL increased from 3.02 to 3.73 in the P group and decreased from 3.62 to 3.37 and 3.43 to 3.27 in the 1X and 4X groups, respectively (p<.04). Differences in insulin concentration and glucose tolerance, markers of insulin function, were not significant between groups. Since some lipid parameters were altered, yet glucose tolerance was unchanged, these data support independent effects of Cr on glucose and lipid metabolism.