Thyroid Dysfunction in Chronic Renal Failure

Abstract

A B S T R A C T Thyroid function was evaluated in 46patients with end-stage kidney disease and 42 normal subjects. Patients were studied before and after the institution of maintenance hemodialysis (HD) and after renal transplantation (RT). Serum total triiodothyronine concentrations (TT3, ng/100 ml, mean± SD) were 63±17 and 83±22 in the non-HD and HD groups, respectively. Values from normal subjects were 128±25 and from RT patients 134±20. The TT3 was in the hypothyroid range (<78 ng/100 ml; 2 SD below normal mean) in 80% of non-HD and 43% of HD patients. Mean serum total thyroxine concentration (TT4), although within the normal range, was lower than the control value. T4-binding globulin capacity was also slightly lower but the difference was not statistically significant. Among patients whose TT4 was 1 SD below the normal mean, the free T4 index was equally depressed, suggesting that factors other than decreased binding capacity might be responsible for the low TT4. In addition, there was a 37% incidence of goiter. Mean serum thyroid-stimulating hormone (TSH) was not elevated and the TSH response to thyrotropinreleasing hormone (TRH) was distinctly blunted, suggesting the possibility of pituitary dysfunction as well. In vivo '25I-L-T4 and 13'I-L-T3 kinetics during 0.2 mg/day of L-T4 replacement showed marked reduction in T3 turnover rate in the uremic patients, both before and during HD; the values (,tg T3/day, mean±SD) for the different groups were as follows: normal, 33.8+6.1; non-HD, 13.5±2.6; HD, 12.9±3.1; and RT, 30.3±7.1.The low T3 turnover rate was due to impaired extrathyroidal conversion of T4 to T3. The mean perThis work was presented in part at the 50th Annual

Peripheral Serum Thyroxine, Triiodothyronine and Reverse Triiodothyronine Kinetics in the Low Thyroxine State of Acute Nonthyroidal Illnesses

“…The T3 PR was markedly reduced in our patients, which is a feature common to other nonthyroidal illnesses (6)(7)(8). T3 production could be reduced as a result of decreased free T4 availability or to impaired enzymatic deiodination of T4.…”

“…roxine (TT4)' in association with normal serum thyrotropin (TSH) levels (1)(2)(3)(4)(5). In addition, total serum triiodothyronine (TT3) levels are decreased, and total reverse T3 (TrT3) values are usually increased (1, [3][4][5], as in other nonthyroidal illnesses (6)(7)(8)(9).…”

Response of hepatic mitochondrial alpha-glycerophosphate dehydrogenase and malic enzyme to constant infusions of L-triiodothyronine in rats bearing the Walker 256 carcinoma. Evidence for divergent postreceptor regulation of the thyroid hormone response.

“…In the human being, nonthyroidal illness results in marked alterations in thyroid hormone concentrations and binding to serum proteins (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Many patients with a variety of nonthyroidal disorders have normal circulating L-thyroxine (T4)' with an increase in free T4.…”

Variable Thyrotropin Response to Thyrotropin-releasing Hormone after Small Decreases in Plasma Free Thyroid Hormone Concentrations in Patients with Nonthyroidal Diseases

“…Despite the decrease in serum T3 and FT3-I, and variable changes in serum T4 and FT4-I, serum TSH and the TSH response to TRH have been normal in most reports of patients with nonthyroidal diseases (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). However, Bermudez et al (3) showed that a small increase in the TSH response to TRH occurred in sick patients with decreased serum T3as compared with similar patients with serum T3 in the normal range; and Burroughs et al (11) reported that the TSH response to TRH was blunted in about one-third of euthyroid geriatric patients with a variety of nonthyroidal diseases.…”

“…Changes occur frequently in peripheral thyroid hormone metabolism and in results of tests of thyroid function in patients with acute and chronic nonthyroidal diseases (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Characteristic laboratory data in such patients include normal to slightly decreased serum thyroxine (T4)l concentration and decreased serum T4 binding.…”