Endocrine changes after burns: the bone involvement.

Any major burn is followed by a pronounced endocrine and metabolic response, by an acute phase response. In 30 burn subjects whose bone status was studied after burn trauma with the densitometer HOLOGIC 2000, bone involvement was found 6 and 12 months postburn: the Bone Mineral Density (BMD) of their lumbar vertebrae L1-4 and of their left hip dropped significantly in most of them. Elevated levels of cortisol both in blood and in urine (free cortisol) were found, accompanied by very low testosterone, dihydrotestosterone (DHT) and free testosterone levels in blood of the burned males, but not of the females. Elevated 17beta-estradiol levels were found in many burned males; they were generally not low in the burned females. DHEA-S levels were generally low. Very low levels of the triiodothyronine (T3) and of the free thyroxine (FT4) were found. Increased, even very high, PTH values were occasionally present. hGH and IGF-1 were generally normal, with a few exceptions (low or increased levels). Total and ionized calcium levels were low after burn, 250H vitamin D (calcidiol) was usually low or low normal too. Prolonged and very high levels of CTX and of NTX (both are indicators of bone resorpcion, of collagen catabolism) were found, as well as of the ACP (acid phosphatases), but the latter were less manifest, if compared with the CTX and NTX. ALP (alkaline phosphatases) were elevated too, but their elevated levels were much less pronounced than the levels of CTX and NTX. Osteocalcin levels were initially low to low normal, to increase later to the normal levels. As for the cytokines that had been investigated, mostly the elevated levels of TNFalpha were found, as well as those of IL-2, IL-6 and IL-8. Finally, a few suggestions have been given regarding the additional possibilities how to treat the burned patients: the use of anabolics, of vitamin D, of calcium, eventually of calcitonin.