Pituitary-testicular axis dysfunction in burned men.

Plasma total testosterone, free testosterone, LH, and sex hormone-binding globulin (testosterone-estradiol-binding globulin) were measured in adult men hospitalized for treatment of burns. Total testosterone was below the normal range in 37 of 41 patients. Free and total testosterone levels declined very rapidly after the burn, remained low for weeks, and rose toward the end of hospitalization, but usually had not reached normal levels at discharge. The more severe the burns, the lower were the testosterone levels. LH levels were below normal during the first 4 days after the burn and remained in the low or mid normal range thereafter. Sex hormone-binding globulin levels were normal or slightly low. The data suggest the presence of a central defect in the release of LH. Large doses of opiate analgesics or an increase in endogenous opiate peptides related to severe persistent pain might be contributing factors to the pituitary-testicular hypofunction found in burned men.