triiodothyronine--reverse and Wounds-and-Injuries

To investigate whether early selenium (Se) supplementation can modify the post-traumatic alterations of thyroid hormone metabolism, since the first week after trauma is characterised by low plasma Se and negative Se balances.. Prospective, placebo-controlled randomised supplementation trial.. Surgical ICU in a tertiary university hospital.. Thirty-one critically ill trauma patients aged 42 +/- 16 years (mean +/- SD), with severe multiple injury (Injury Severity Score 30 +/- 7).. Supplementation during the first 5 days after injury with either Se or placebo. The selenium group was further randomised to receive daily 500 microg Se, with or without 150 mg alpha-tocopherol (AT) and 13 mg zinc supplements. The placebo group received the vehicle. Circulating Se, AT, zinc, and thyroid hormones were determined on D0 (= day 0, admission), D1, D2, D5, D10, and D20.. Plasma Se, low on D0, normalised from D1 in the selenium group; total T4 and T3 increased more and faster after D2 (P = 0.04 and 0.08), reverse T3 rising less between D0 and D2 (P = 0.05).. Selenium supplements increased the circulating Se levels. Supplementation was associated with modest changes in thyroid hormones, with an earlier normalisation of T4 and reverse T3 plasma levels. The addition of AT and zinc did not produce any additional change.

Topics: Adult; Analysis of Variance; Antioxidants; Drug Therapy, Combination; Euthyroid Sick Syndromes; Humans; Prospective Studies; Selenium; Thyroxine; Triiodothyronine, Reverse; Vitamin E; Wounds and Injuries; Zinc

Different elements of the hypothalamic-pituitary-thyroid axis have been found to be implicated in the normal physiology of the human skin. Their effects on wound healing and hair growth in rats have been described previously. There is close homology between the thyroid hormone receptors in humans and guinea pigs.. To assess the effect of different doses of topical 3,3',5-triiodo-L-thyronine (T3) and recombinant human thyroid-stimulating hormone (TSH) on wound healing in guinea pigs.. Wounds were dressed every other day for 7 days, during which clinical measurements of the wounded areas were performed. Histological examination was performed at the end of the study.. Application of high and low concentrations of topical T3 but not TSH demonstrated a significant dose-dependent reduction in the wound surface area through a process of contraction. The main significant histological result was an increase in the hair-follicle count.. Topical T3 enhances wound healing in guinea pigs, primarily by wound contraction. As this is a critical stage in healing of chronic ulcers, topical T3 could be a useful treatment for wounds.

Topics: Administration, Topical; Analysis of Variance; Animals; Dermatologic Agents; Dose-Response Relationship, Drug; Guinea Pigs; Hair Follicle; Male; Prospective Studies; Recombinant Proteins; Thyrotropin; Triiodothyronine, Reverse; Wound Healing; Wounds and Injuries

Topics: Animals; Catecholamines; Fasting; Female; Fluorescent Antibody Technique; Glucose; Kidney; Kinetics; Liver; Male; Rats; Rats, Inbred Strains; Swine; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse; Water Deprivation; Wounds and Injuries; Wounds, Gunshot

Alterations in circulating thyroid hormone concentrations occur in a variety of nonthyroidal disease states. In the present study, thyroid hormone levels were measured every 8 to 12 hours in 19 otherwise healthy individuals suffering acute severe trauma necessitating admission to the Maryland Institute for Emergency Medical Services Systems. Four fatalities occurred within 48 hours of admission. The mean total T3 level fell rapidly after the onset of trauma and remained low throughout the observation period. Reverse T3 rose concurrent with the fall in T3 but gradually returned to normal in the survivors. Total and free T4 levels remained normal in the survivors but fell below normal in the fatalities on the samples obtained preceding death. Changes in free T4 were consistent in three separate radioimmunoassay systems. Pharmacologic doses of glucocorticoids administered to seven of the 15 survivors and to the four fatalities did not result in an acute depression in total and free T4 levels in the survivors. Post-mortem examination of three fatalities did not reveal evidence of significant thyroid or pituitary disease. These results suggest that in acutely traumatized patients: 1) T3 declines rapidly and remains depressed throughout the illness; 2) continued fall of T4 to subnormal levels is associated with a poor prognosis; and 3) steroid therapy alone cannot explain the acute changes observed in hormone levels.

Topics: Acute Disease; Adolescent; Adult; Aged; Female; Glucocorticoids; Humans; Male; Middle Aged; Prognosis; Thyroxine; Time Factors; Triiodothyronine; Triiodothyronine, Reverse; Wounds and Injuries

In order to evaluate the effects of severe trauma on the levels of thyroxine (T4), 3,3',5-triiodothyronine (T3), and 3,3',5'-triiodothyronine (reverse-T3, r-T3), blood samples were collected from traumatized patients on the first post-trauma day. The plasma concentrations of T3 were significantly decreased (mean, 47.4 ng/dl); T4 levels were in the normal range (mean, 6.6 mcg/dl) and r-T3 levels were significantly elevated (mean, 80.8 ng/dl). The oxygen extraction by the muscular tissue was also determined in these patients and found to be elevated; however, no correlation could be established between the extraction ratios and the thyroid hormone levels. This deviation in the peripheral conversion of T4 into r-T3 with a decreased production of T3 also accompanies severe systemic illnesses and probably represents a form of T4 inactivation conditioned by the metabolic demands of the body. This alternate pathway of thyroid hormone metabolism is enhanced by elevated blood levels of catecholamines, glucose, or glucocorticoids as well as by decreased insulin plasma concentrations, all known to follow major trauma and other catabolic conditions.

Topics: Adult; Aged; Humans; Male; Middle Aged; Muscles; Oxygen Consumption; Surgical Procedures, Operative; Thyroid Hormones; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse; Wounds and Injuries

Thyroid function tests were obtained from 335 consecutive patients admitted to an intensive care unit. Twenty patients suffering from severe non-endocrine diseases (septicaemia, fulminant hepatic and renal failure, acute pancreatitis, polytrauma, cerebral haemorrhage) were found to have serum thyroxine levels in the hypothyroid range (less than 4 micrograms/dl). Serum concentrations of total thyroxine (2.3 +/- 0.2 micrograms/dl), triiodothyronine (0.23 +/- 0.03 ng/ml), and thyroxine binding globulin (15.1 +/- 1.3 micrograms/ml) were reduced, but were above normal for reverse triiodothyronine (0.43 +/- 0.06 ng/ml). Response of TSH secretion to iv TRH was found to be either normal, lowered or absent. Primary hypothyroidism was excluded, as no enhanced TSH response was observed in any case. Although decreased thyroxine levels may be due to increased thyroid hormone degradation it appears that associated impaired TSH responsiveness to TRH may result from illness-related inhibition of pituitary TSH release. Although the finding of decreased thyroid hormone levels is not rare in care patients, it represents an index of poor prognosis. Differentiation between this "low-T4 syndrome" and true hypothyroidism depends essentially on clinical symptoms and course of disease.

Topics: Acute Disease; Acute Kidney Injury; Adolescent; Adult; Aged; Critical Care; Female; Hepatic Encephalopathy; Humans; Hypothyroidism; Male; Middle Aged; Pancreatitis; Pituitary Gland; Sepsis; Thyroid Function Tests; Thyroid Gland; Thyrotropin; Thyroxine; Thyroxine-Binding Proteins; Triiodothyronine; Triiodothyronine, Reverse; Wounds and Injuries