CHROMIUM PICOLINATE SUPPLEMENTATION AND RESISTIVE TRAINING BY OLDER MEN - EFFECTS ON IRON-STATUS AND HEMATOLOGIC INDEXES

Chromium competes with iron for binding to transferrin, and high-dose chromium supplementation has been hypothesized to adversely affect iro n status. This study examined the effects of chromium picolinate suppl ementation on hematologic indexes and selected indexes of iron status in 18 men aged 56-69 y who participated in an introductory resistive t raining program. The men were randomly assigned (double-blind design) to groups (n = 9) that consumed either 17.8 mu mol Cr/d (924 mu g Cr/d ) as chromium picolinate or a low-chromium placebo for 12 wk while eng aging in resistive training twice weekly (3 sets of 8-12 repetitions a t 80% of one repetition maximum for 5 exercises). Hematocrit, hemoglob in, red blood cell (erythrocyte) count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red blood cell distribution width, platelet count, and mean platelet volu me were within normal clinical ranges and were unchanged by either chr omium picolinate supplementation or resistive training. Resistive trai ning decreased total-iron-binding capacity from 38.4 +/- 9.3 to 27.3 /- 5.6 mu mol/L (P < 0.0001) and increased transferrin saturation from 35.7 +/- 16.3% to 45.4 +/- 16.9% (P = 0.050). Chromium picolinate sup plementation did not influence these responses. Serum iron concentrati ons and serum ferritin concentrations were unchanged by either resisti ve training or chromium picolinate supplementation. These data suggest that high-dose chromium picolinate supplementation for 12 wk did not influence hematologic indexes or indexes of iron metabolism or status in older men. The decrease in total-iron-binding capacity and increase in transferrin saturation (%) with resistive training are largely opp osite to changes associated with iron depletion and suggest a novel ef fect of resistive training on iron transport.