Corticosteroid-binding Globulin, Cortisol, Free Cortisol, and Sex Hormone-binding Globulin Responses Following Oral Glucose Challenge in Spinal Cord-injured and Able-bodied Men

Circulating cortisol, corticosteroid-binding glob- ulin, and sex hormone-binding globulin were measured retrospectively in plasma samples following the oral glucose tolerance test in 20 spinal cord-injured men and 20 able-bodied con- trols. Plasma-free cortisol responses attenuated more rapidly in the able-bodied men, compared to spinal cord-injured subjects, due to signicant rise in circulating corticosteroid-binding globu- lin whereas changes in total plasma cortisol were similar in both groups. The changes in plasma- free cortisol in both groups paralleled changes in insulin and glucose and show that spinal cord- injured men had heightened exposure to free cortisol during this dynamic test. This raises the possibility that the mechanism of abdomi- nal obesity and the propensity towards insulin resistance in spinal cord-injured men could be subtly mediated by perturbations in free cortisol. There were no signicant changes in plasma sex hormone-binding globulin in either group.