pituitrin and Myxedema

We monitored the plasma and urine osmolalities, fractional excretion of sodium, fractional excretion of chloride, plasma levels of antidiuretic hormone (ADH, AVP), aldosterone and atrial natriuretic peptide (ANP) before and after acute water ingestion in 12 patients with overt hypothyroidism. The ability of the patients to dilute and concentrate urine was found impaired and the ability of excretion of water load decreased and delayed. Acute water load test was proved to be effective in evaluating the urinary excreting function for the patients. We hypothesize that inappropriate secretion of anti-diuretic hormone and elevated plasma ANP may be homeostatic factors for abnormal urinary excretion in patients with hypothyroidism.

Topics: Adolescent; Adult; Aldosterone; Atrial Natriuretic Factor; Body Water; Female; Humans; Male; Middle Aged; Myxedema; Natriuresis; Osmolar Concentration; Vasopressins; Water-Electrolyte Balance

We studied osmoregulation of plasma vasopressin (AVP) in eight patients with untreated myxedema due to primary hypothyroidism. All patients had severe thyroid hormone deficiency due to chronic thyroiditis and had been receiving no medication at the time of this study. AVP release was defined by 5% hypertonic saline infusion test in all patients, and urinary diluting capacity was estimated by the iv water-loading tests in five patients. Plasma AVP was measured by sensitive and specific RIA. The mean basal plasma AVP level in the patients (0.5 +/- 0.1 pmol/L) was significantly lower (P less than 0.01) than that in normal adults (2.5 +/- 0.5 pmol/L). During hypertonic saline infusion, the rise in plasma AVP was normal or subnormal in all patients. In two patients who showed mild to moderate hyponatremia in the basal state and mild urinary diluting defect during water loading, plasma AVP was appropriately suppressed in each case. These results indicate that inappropriate elevation of plasma AVP is not common in myxedema, and that impaired water excretion is due mainly to AVP-independent mechanisms.

Topics: Adult; Aged; Female; Humans; Hypothyroidism; Middle Aged; Myxedema; Osmolar Concentration; Radioimmunoassay; Thyroid Hormones; Thyrotropin; Vasopressins; Water Deprivation; Water-Electrolyte Balance

Hyponatremia is usual during myxedema coma. Hereafter we report two cases with increased plasma arginine vasopressin (AVP). Patients were admitted because of hypothyroid coma. In each case, there was an hyponatremia with normal urine sodium and low serum osmolality. Renal function was normal. On hormonal results, primary hypothyroidism was evident. Plasma AVP was increased. The plasma cortisol of one patient was high. Immediate therapy associated: water restriction, hypertonic saline infusion, furosemide, oral thyroid hormones with low doses. On the fourth day, conscience improved obviously. Natremia and plasma AVP went back to normal state before returning to euthyroid state. Patients went on improving along with normalizing thyroid status. Hyponatremia can be a serious sign of hypothyroidism. In case of myxedema coma with hyponatremia, clinical improvement seems to be related to fast correction of water and electrolyte disturbances and we prefer to give low doses of thyroid hormones at first. The hyponatremia and increased plasma AVP mechanisms are complex. However, in each of these cases, plasma AVP come back to normal before returning to euthyroid state. In one case, high plasma cortisol level rules out adrenal insufficiency as causal mechanism of electrolyte disorders.

Topics: Aged; Coma; Female; Humans; Hyponatremia; Hypothyroidism; Male; Myxedema; Vasopressins

A 45-year-old woman with myxedema coma due to primary hypothyroidism manifested hyponatremia, impaired water excretion, and elevated urine osmolarity as well as natriuresis suggestive of a syndrome of inappropriate antidiuretic hormone secretion. However, plasma vasopressin was undetectable or very low and plasma aldosterone levels were suppressed in the presence of hyponatremia. Subsequent replacement therapy with levothyroxine caused a rapid decline in sodium clearance which was independent of the change in glomerular filtration rate, and corrected the impaired water excretion and hyponatremia. Plasma vasopressin levels returned to the normal range after the correction of hyponatremia. Thus, the results indicate that neither vasopressin nor aldosterone plays a dominant role in the pathogenesis of the hyponatremia in this patient. It appears that thyroid hormone deficiency itself caused the derangement of tubular cell function, which resulted in the development of the impaired water excretion and hyponatremia.

Topics: Coma; Female; Glomerular Filtration Rate; Humans; Hyponatremia; Hypothyroidism; Inappropriate ADH Syndrome; Middle Aged; Myxedema; Osmolar Concentration; Sodium; Thyroxine; Vasopressins

The plasma vasopressin response to acute water ingestion was evaluated in 20 patients with myxedema prior to definitive treatment and in eight of these same patients following therapy of their hypothyroidism. Vasopressin levels were elevated and failed to completely suppress following water ingestion in 15 subjects (75 per cent). Two hypothyroid patients with elevated plasma vasopressin levels (10 per cent) had a normal renal response to the water challenge suggesting partial end organ hormonal unresponsiveness. In three (15 per cent) of the five patients with suppressible vasopressin, water excretion was impaired indicating a nonvasopressin-mediated renal defect. In eight patients restudied after achievement of a euthyroid state, vasopressin inhibition and urinary excretion were normal following the oral water load. Although intrinsic renal changes in the hypothyroid state may contribute to the observed defect in water diuresis, the present study suggests a role of endogenous vasopressin in this disorder.

Topics: Adult; Aged; Arginine Vasopressin; Body Water; Humans; Hypothyroidism; Male; Middle Aged; Myxedema; Vasopressins; Water

A case report is presented in which myxedema coma and inappropriate antidiuretic hormone secretion developed as a result of radiation therapy and surgery to the neck area in a patient with recurrent metastatic squamous cell carcinoma of the floor of the mouth. Laboratory findings of low thyroxine level and the findings of persistent hyponatremia and hypoosmolality of serum in spite of persistent sodium loss in the urine were helpful in diagnosing the problem. Treatment included thyroid hormone replacement and fluid restriction resulting in complete reversal of her condition. We believe that patients with head and neck cancer who have undergone a course of radiation to the neck, and particularly when thyroid function might have been altered by previous subtotal thyroidectomy as part of a curative resection, should be carefully followed with periodic thyroid function assays and serum electrolytes with particular attention to serum sodium values.

Topics: Carcinoma, Squamous Cell; Coma; Female; Head and Neck Neoplasms; Humans; Hyponatremia; Hypothyroidism; Middle Aged; Myxedema; Neoplasm Metastasis; Radiation Injuries; Vasopressins

The authors report a case of coma due to peripheral myxoedema with severe hyponatremia (111 mq) and low urinary sodium. The clinical and metabolic disorders regressed within ten days under treatment with thyroid. The frequency of hyponatremia during myxoedema coma is recalled and the pathogenic mechanism discussed. Although the adrenal origin seems excluded, there is possibly some hypervasopresinism, but it seems finally that the thyroxin-dependent hyponatremia is of renal origin.

Topics: Coma; Female; Humans; Hydrocortisone; Hyponatremia; Hypothyroidism; Kidney; Male; Mineralocorticoids; Myxedema; Vasopressins

Indwelling, exteriorized, jugular vein catheters were placed in five thyroidectomized ewes at a time when myxedema was manifested clinically and chemically and three euthyroid sheep were used as controls. Post-operatively, tracer doses of [125I]-iodovasopressin were injected and serial blood specimens were obtained for determination of volume of distribution, plasma disappearance, and blood production rates. Serum vasopressin was measured by radioimmunoassay. The mean volumes of distribution for vasopressin in the hypothyroid and euthyroid sheep, respectively, were 8.15 and 5.90 liters, mean t1/2 of vasopressin 9.5 and 19.3 min, mean serum vasopressin concentrations 5.1 and 1.2 muU/ml, and mean blood production rates 2.84 and 0.23 mU/kg/h. Renal and organ biologic effectiveness of the elevated vasopressin levels was suggested by the lowered serum osmolalities in the hypothyroid sheep over controls (272 vs. 301 mosmol/kg). These results suggest an augmented secretion of vasopressin in the myxedematous state.

Topics: Animals; Arginine Vasopressin; Female; Myxedema; Sheep; Thyroidectomy; Vasopressins

Twenty-six patients with the syndrome of inappropriate secretion of antidiuretic hormone were reviewed. The underlying diseases were bronchogenic carcinoma (12 cases); myxoedema (five cases); diseases of the nervous system (five cases); bronchopneumonia, carcinoma of the oesophagus, acute intermittent porphria and chlorpropamide therapy (each one case). Serum sodium levels ranged between 104 and 125 mEq per litre. Eighteen patients presented neurological manifestations, which in 14 were considered to be due to hyponatraemia. Neurological signs included disorders of consciousness (stage I and II coma), extrapyramidal signs, asterixis and epileptic seizures. An hyponatraemic coma was the first manifestation of the syndrome in five cases. In all cases where the EEG was recorded it showed non-specific signs of metabolic coma. The fundi never showed signs of intracranial hypertension. Blood urea and creatinine levels were invariably low in the euthyroid patients; these values were normal or elevated in patients with myxoedema and hyponatraemia. Hypokalaemia was frequent, and hypocalcaemia constant. In eleven cases an excess of water intake revealed the clinical syndrome: six patients were excessive beer drinkers and five had received extensive intravenous infusions. In one case the deleterious effect of diuretics was evident, and in another, the syndrome became evident during radiotherapy of an oesophageal tumour. Treatment of the syndrome was successful in all cases. A review of the literature concerning the various pathogenic mechanisms corresponding to the different underlying diseases is presented. The concept of aberrant hormonal production by a tumour is illustrated by an electron microscopic study.

Topics: Adult; Aged; Carcinoma, Bronchogenic; Cerebrovascular Disorders; Esophageal Neoplasms; Female; Hormones, Ectopic; Humans; Hyponatremia; Hypothyroidism; Lung Neoplasms; Male; Middle Aged; Myxedema; Neurologic Manifestations; Vasopressins; Water Intoxication

Topics: Heart Failure; Humans; Hyponatremia; Liver Cirrhosis; Myxedema; Pituitary Diseases; Radioimmunoassay; Vasopressins

Topics: Aged; Diuresis; Humans; Male; Myxedema; Osmolar Concentration; Vasopressins; Water-Electrolyte Balance

Topics: Adult; Aged; Body Weight; Cholesterol; Diuresis; Female; Glomerular Filtration Rate; Humans; Hydrocortisone; Hyponatremia; Kidney; Male; Middle Aged; Myxedema; Osmolar Concentration; Potassium; Sodium; Thyroid Gland; Thyroid Hormones; Thyroxine; Vasopressins; Water-Electrolyte Balance

Topics: Adult; Aged; Female; Glomerular Filtration Rate; Humans; Kidney Concentrating Ability; Kidney Function Tests; Kidney Glomerulus; Kidney Tubules; Lung Neoplasms; Male; Mannitol; Middle Aged; Myxedema; Natriuresis; Osmolar Concentration; Triiodothyronine; Vasopressins; Water-Electrolyte Balance

Topics: Aged; Female; Humans; Hyponatremia; Injections, Intravenous; Myxedema; Osmolar Concentration; Thyroid Hormones; Thyroxine; Vasopressins

Topics: Carcinoma; Diagnosis, Differential; Exudates and Transudates; Female; Humans; Hyponatremia; Intestinal Obstruction; Middle Aged; Myxedema; Osmolar Concentration; Pelvic Inflammatory Disease; Pelvic Neoplasms; Sodium; Thyroid Hormones; Vasopressins; Water Intoxication; Water-Electrolyte Balance

Topics: Adult; Aged; Blood Glucose; Fatty Acids, Nonesterified; Female; Glucocorticoids; Growth Hormone; Humans; Hypothalamus; Insulin; Male; Middle Aged; Myxedema; Pituitary Gland; Vasopressins

Topics: Adolescent; Adrenal Glands; Adrenocorticotropic Hormone; Adult; Aged; Female; Humans; Hydrocortisone; Injections, Intramuscular; Lysine; Male; Metyrapone; Middle Aged; Myxedema; Pituitary Gland; Pituitary-Adrenal Function Tests; Pituitary-Adrenal System; Stimulation, Chemical; Thyroxine; Vasopressins

Topics: Humans; Hypertension; Hypogonadism; Hypothyroidism; Myxedema; Thyroid Function Tests; Vasopressins

Topics: Aged; Female; Humans; Hyponatremia; Hypothyroidism; Myxedema; Sodium; Thyroid Hormones; Vasopressins; Water-Electrolyte Balance

Topics: Carcinoma, Bronchogenic; Endocrine System Diseases; Hormones, Ectopic; Humans; Hyponatremia; Infections; Lung Neoplasms; Male; Middle Aged; Myxedema; Pituitary Diseases; Porphyrias; Vasopressins

Topics: Aged; Heart Failure; Humans; Hyponatremia; Hypopituitarism; Male; Myxedema; Propylthiouracil; Triiodothyronine; Vasopressins

Topics: Adrenocorticotropic Hormone; Cushing Syndrome; Female; Humans; Hydrocortisone; Insulin; Liver Diseases; Metyrapone; Myxedema; Obesity; Pituitary-Adrenal Function Tests; Pregnancy; Vasopressins

Topics: Amphetamine; Amyl Nitrite; Atropine; Edema; Female; Humans; Liver Diseases; Myxedema; Pre-Eclampsia; Pregnancy; Premenstrual Syndrome; Sodium Chloride; Vasopressins

Topics: Coma; Congenital Hypothyroidism; Female; Humans; Hyponatremia; Infant; Myxedema; Vasopressins; Water Intoxication

Topics: Drug Therapy; Geriatrics; Humans; Hyponatremia; Myxedema; Thyroid Function Tests; Thyroxine; Vasopressins; Water-Electrolyte Balance

Topics: Diabetes Insipidus; Diabetes Insipidus, Neurogenic; Disease; Humans; Medical Records; Myxedema; Pituitary Gland; Pituitary Gland, Anterior; Thyroid Gland; Vasopressins