The thyroid in end-stage renal disease.

Previous studies of patients with end-stage renal disease (ESRD) indicate that the prevalence of goiter varies from 0 to 58% while that of hypothyroidism ranges from 0 to 9.5%. In addition, altered serum thyroid hormone levels are present in euthyroid patients with ESRD and may be related to nonthyroidal disorders including malnutrition. To examine these issues further, 306 patients with ESRD were compared to 139 hospitalized patients without renal disease (control population). Goiter was present in 43% with ESRD compared to 6.7% of controls (P less than 0.001). Goiter frequency was greater (49.6%, P = 0.047) and serum parathyroid hormone levels higher (mean: 238.6 microlitersEq/ml, P less than 0.001; normal: less than 15 microlitersEq/ml) in 115 patients dialyzed for longer than 1 year than in 191 dialyzed for less than 1 year or not at all (38.7%, and 61.5 microlitersEq/ml, respectively). In addition, goiter was more common in females (50.0%) than in males (35.1%, P = 0.008) with ESRD. No significant relationships were observed between goiter frequency and age, race, diabetes mellitus, or elevated antimicrosomal antibody titers. The prevalence of primary hypothyroidism was higher in ESRD (2.6%) than in 2122 in- and out-patients (1.1%) (P = 0.024). Compared to the total group of ESRD patients, the hypothyroid patients were predominantly female (88% vs. 50%) and had a higher frequency of positive antimicrosomal antibody titers (50% vs. 6.7%, P = 0.029). The frequency of hyperthyroidism was not significantly different, being 1.0% in ESRD compared to 0.3% in the general population (P = 0.057). There was a higher frequency of reduced free T4 index values in the 287 euthyroid patients with ESRD (12.9%) than in controls (3.6%) (P = 0.002). Similarly, free T3 index values were reduced below 100 in 65.5% with ESRD compared to 33.8% of controls (P less than 0.001). In addition, serum albumin levels were lower in euthyroid patients with ESRD (3.5 g/dl, P less than 0.001) than in controls (3.8 g/dl). Serum T3 levels correlated directly with both serum albumin (r = 0.57, P less than 0.001) and transferrin (r = 0.54, P less than 0.001) levels in ESRD as well as in controls (r = 0.74, P less than 0.001, and r = 0.69, P less than 0.001, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute hemodynamic effects of levothyroxine loading in critically ill hypothyroid patients.

To evaluate the acute cardiovascular effects of high-dose levothyroxine sodium therapy, the hemodynamic findings in eight critically ill hypothyroid patients treated with high-dose levothyroxine were compared with those in two critically ill hypothyroid and nine critically ill euthyroid patients not receiving this therapy. The initial cardiac index was significantly lower in the hypothyroid group; all other hemodynamic values were similar to those of the euthyroid patients. Following levothyroxine loading, the free thyroxine index increased to normal while the free triiodothyronine index was unchanged; all patients had a significant rise in cardiac index but no consistent changes in the other hemodynamic values. Cardiac index correlated positively with heart rate (three patients) and/or stroke volume index (six patients). Increases in stroke volume index correlated with decreases in systemic vascular resistance (five patients), but not with increases in pulmonary artery wedge pressure. No consistent patterns of hemodynamic changes were observed in the untreated hypothyroid or the euthyroid patients.

Serum thyroid hormone indexes in patients with primary hyperparathyroidism.

Serum total reverse triiodothyronine (rT3) levels are normal in patients with renal diseases with and without renal insufficiency but elevated in nonrenal nonthyroidal illnesses. To evaluate the role of secondary hyperparathyroidism of renal diseases in this difference, serum thyroid hormone levels were studied in 27 patients with primary hyperparathyroidism (PHP) and normal renal function. In PHP, total T3 levels were reduced (118 +/- 6 ng/dL, normal: 147 +/- 3 ng/dL) and correlated with PTH levels. Serum rT3 levels were also decreased (27 +/- 3 ng/dL, normal: 34 +/- 2 ng/dL). Values for serum total thyroxine (T4), T3 uptake ratio, free T4 index, and thyrotrophin were not altered. Serum rT3 levels were increased (63 +/- 13 ng/dL) in patients with hypercalcemia due to malignant neoplasms who had low T3 levels, undetectable PTH and normal renal function. Thus, PTH excess may be the factor responsible for the failure of rT3 levels to increase in PHP and secondary hyperparathyroidism.

Severe hyperuricemia in patients with volume depletion.

Profound hyperuricemia (19-42 (27 +/- 3.3) mg/dl) was noted in seven adult patients with volume depletion and marked prerenal azotemia (SUN, 155 +/- 30 mg/dl and serum creatinine 5.2 +/- 1.1 mg/dl). The serum level of uric acid returned to normal following the administration of 3.2 +/- 0.4 liters of saline/day over a period of 3.4 +/- 0.6 days. Throughout the course of the illness, there were significant correlations (r = 0.83, p less than 0.01) between the serum levels of both urea nitrogen and creatinine and those of uric acid. Because of the rapid reversibility of this hyperuricemia with hydration, it should be differentiated from other clinical conditions associated with acute renal failure and profound hyperuricemia.