salicylates and Hypothyroidism

Topics: Blood Chemical Analysis; Blood Proteins; Chemistry, Clinical; Chromatography, Ion Exchange; Clinical Trials as Topic; Diatrizoate; Humans; Hyperthyroidism; Hypothyroidism; Iopanoic Acid; Methods; Phenytoin; Protein Binding; Salicylates; Thyroxine

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Cardiomyopathies; Clinical Laboratory Techniques; False Positive Reactions; Humans; Hyperlipidemias; Hypothyroidism; Indicators and Reagents; Lipids; Male; Salicylates; Spectrophotometry, Ultraviolet

To evaluate how the nonsteroidal anti-inflammatory agent salsalate affects the results of routine thyroid function tests.. In a cohort of patients taking salsalate for various rheumatic conditions, thyroid function tests were performed with patients on and off the drug.. Primary care of ambulatory patients in a university medical center.. A convenience sample of 14 euthyroid subjects, none of whom was taking thyroid hormone or other medication recognized to alter thyroid function.. Treatment with therapeutic doses of salsalate for a mean period of 44 weeks.. Serum levels of thyroxine (T4), free T4, thyroid hormone binding ratio, free T4 index (the product of T4 and the thyroid hormone binding ratio), triiodothyronine, and thyrotropin.. Serum T4 dropped from a mean baseline level of 96.7 nmol/L off salsalate to 53.4 nmol/L on it (P less than .001), and the free T4 index showed a parallel decline from 85.9 to 50.4 (P less than .001), with both values falling into the hypothyroid range. Similarly, free T4 levels and total triiodothyronine concentrations were low in several patients treated with salsalate. Serum thyrotropin levels declined transiently, falling from a mean of 3.2 to 1.7 mU/L (P less than .02) in patients treated for less than 3 weeks. Patients treated for longer periods had levels comparable to baseline. Despite these changes in the thyroid function test results, all subjects remained clinically euthyroid.. Salsalate commonly produces abnormalities in routine thyroid function test results similar to those found in central hypothyroidism.

Topics: Adult; Aged; Aged, 80 and over; Cohort Studies; Female; Humans; Hypothyroidism; Male; Middle Aged; Rheumatic Diseases; Salicylates; Thyroid Function Tests; Thyroid Gland; Thyroid Hormones; Thyroxine

Progressive dilution of normal sera causes little change in free T4 concentrations. Similar dilution of sera containing drug inhibitors of T4 binding to serum proteins causes a progressive fall in free T4. The low T4 syndrome of nonthyroidal illness is thought to be associated with a circulating inhibitor(s) of T4 binding. It would be expected, therefore, that dilution of sera from the low T4 syndrome might also result in a fall in free T4 concentrations. We compared the effect of progressive serum dilution on free T4 concentrations in low T4 syndrome sera to those in normal, hyperthyroid, pregnancy, TBG-deficient and salicylate-containing sera. A tracer dialysis method proved inappropriate for studying dilution effects. Using a new dialysate RIA method to measure free T4, we found a progressive fall in free T4 concentrations in sera from patients with the low T4 syndrome similar to that in serum containing salicylate, but not to that in normal sera. The magnitude of the fall varied widely among individual patients. Free T4 methods which use a diluted serum sample will underestimate free T4 concentrations in the low T4 syndrome.

Topics: Adult; Aged; Dialysis; Electrolytes; Female; Humans; Hyperthyroidism; Hypothyroidism; Indicator Dilution Techniques; Male; Middle Aged; Pregnancy; Radioimmunoassay; Salicylates; Salicylic Acid; Thyroxine; Thyroxine-Binding Proteins

We evaluated a new thyroxin analog-based assay for free thyroxin (FT4) (Corning Medical), finding it technically simple and precise (between-assay CVs of 3.3 and 4.2% for FT4 concentrations of 12 and 25 ng/L, respectively). We measured FT4 in a total of 325 serum samples from euthyroid patients; patients receiving replacement thyroxin; patients receiving estrogens or who were pregnant; hyperthyroid, hypothyroid, and non- thyroidally ill patients; and patients receiving salicylates, phenytoin, or heparin. This assay clearly identified hyper- and hypothyroid patients, and produced similar results in euthyroid patients with above-normal, normal, or low concentration of thyroxin-binding globulin. Results in some non-thyroid-illness patients and patients receiving salicylates or phenytoin were low compared with euthyroid patients receiving no medications, but the diagnostic accuracy of the Corning FT4 assay exceeded that of another analog-based assay (Amersham) in these particular groups. We believe the new Corning analog FT4 assay offers an attractive alternative to other commercial FT4 systems.

Topics: Female; Glass; Heparin; Humans; Hyperthyroidism; Hypothyroidism; Male; Methods; Phenytoin; Pregnancy; Reagent Kits, Diagnostic; Salicylates; Thyroxine; Thyroxine-Binding Proteins

Topics: Asthma; Congenital Hypothyroidism; Ephedrine; Female; Goiter; Humans; Hypothyroidism; Infant, Newborn; Iodides; Maternal-Fetal Exchange; Phenobarbital; Pregnancy; Pregnancy Complications; Respiratory Insufficiency; Salicylates; Theophylline

Binding of triiodothyronine (T3) and thyroxine (T4) to nuclei of intact human lymphocytes was studied. The binding characteristics were analysed by Scatchard's method. In lymphocytes from euthyroid healthy subjects there was a single set of saturable nuclear T3 and T4 binding sites with an apparent mean equilibrium association constant of 3.3 X 10(10) l/mol and 1.7 X 10(10) l/mol, respectively. The estimated mean maximal specific binding capacity for T3 was 50 fmol/mg DNA and for T4 was 55 fmol/mg DNA, indicating that these two hormones may have a common receptor. In hyperthyroid and hypothyroid patients nuclear affinity for T3 and T4 was very similar to that for euthyroid reference subjects. In hyperthyroidism, T3 and T4 binding capacity was unaltered, whereas in hypothyroidism it was nearly twice as high as in euthyroidism. Lymphocytes from three members of a family with hereditary peripheral resistance to thyroid hormone action were studied. One set of saturable T3 and T4 nuclear binding sites with affinity constants similar to those in the euthyroid group was found. However, in these subjects the estimated binding capacity for T3 and T4 was rather low, indicating that the biochemical defect in this family might be a mild deficiency of nuclear receptor protein. Incubation with diphenylhydantoin and salicylate added in vitro did not alter the binding of T3 and T4 to lymphocyte nuclei. Nuclear binding was also not affected in patients receiving therapeutic amounts of diphenylhydantoin.

Topics: Adult; Binding, Competitive; Cell Nucleus; Cells, Cultured; Female; Humans; Hyperthyroidism; Hypothyroidism; Lymphocytes; Male; Phenytoin; Salicylates; Thyroxine; Triiodothyronine

The ultimate cause of the clinical abnormalities associated with changes in oxygen supply and oxygen utilization is the development of abnormal tissue oxygen metabolism. Until now, there has been no satisfactory term to describe abnormal tissue oxygen metabolism. We propose the term "dysoxia" to fill this gap. There are a number of causes of dysoxia. One of the most interesting is that form of dysoxia related to abnormal mitochondrial structure and function. In this group of disorders, there is abnormal tissue oxygen metabolism, although oxygen supply is normal. Another interesting cause of dysoxia is exposure to high oxygen concentrations. High oxygen concentrations are involved in producing abnormal tissue oxygen metabolism under a number of different circumstances. The concept underlying dysoxia provides a unified approach to a large and important group of disorders involving most branches of clinical medicine.

Topics: Child; Child, Preschool; Cyanides; Dinitrophenols; Edema; Electron Transport; Humans; Hyperthyroidism; Hypothyroidism; Hypoxia; Infant, Newborn; Iron; Menkes Kinky Hair Syndrome; Mitochondria; Muscles; Oxygen; Oxygen Consumption; Reye Syndrome; Salicylates

Topics: Diuretics; Gout; Humans; Hypertension; Hypothyroidism; Kidney Diseases; Nicotinic Acids; Nucleoproteins; Proteins; Purines; Salicylates; Thioridazine; Uric Acid

Topics: Contraceptives, Oral; Female; Humans; Hyperthyroidism; Hypothyroidism; Injections, Intravenous; Iodine Isotopes; Male; Mathematics; Methods; Phenytoin; Salicylates; Sex Factors; Thyroxine; Time Factors

Topics: Autoanalysis; Basal Metabolism; Cholesterol; Dialysis; Gentisates; Humans; Hypothyroidism; Iodine Isotopes; Protein Binding; Radioimmunoassay; Salicylates; Sodium; Thyrotropin

Topics: Androgens; Antithyroid Agents; Drug Therapy; Estrogens; Humans; Hyperthyroidism; Hypothyroidism; Iodides; Iodine Isotopes; Phenytoin; Protein Binding; Salicylates; Thyroid Function Tests; Thyroid Hormones

Topics: Aminosalicylic Acids; Antithyroid Agents; Goiter; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Hydantoins; Hypothyroidism; Iatrogenic Disease; Iodides; Iodine Isotopes; Perchlorates; Phenothiazines; Phenylbutazone; Pituitary Gland; Radiotherapy; Reserpine; Salicylates; Sulfonamides; Sulfur; Thyroid Hormones

Topics: Blood Protein Disorders; Chromatography, Paper; Estrogens; Humans; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Methods; Phenytoin; Salicylates; Serum Albumin; Thyroid Function Tests; Thyroxine; Thyroxine-Binding Proteins

Topics: Androgens; Chloroquine; Diethylstilbestrol; Estrogens; Female; Humans; Hydrocortisone; Hydroflumethiazide; Hyperthyroidism; Hypothyroidism; In Vitro Techniques; Male; Prednisolone; Pregnancy; Salicylates; Serum Globulins; Testosterone; Thyroid Function Tests; Thyroxine; Thyroxine-Binding Proteins; Tolbutamide