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Thyroxine Replacement (thyroxine + replacement)
Selected AbstractsGastric emptying function changes in patients with thyroid cancer after withdrawal of thyroid hormone therapyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2004PAN-FU KAO Abstract Background:, Hypothyroidism is commonly thought to cause decreased gastric emptying but is mostly associated with autoimmune disease. In the present study the gastric emptying function of thyroid cancer patients with severe hypothyroidism of short duration was evaluated with a radionuclide solid meal gastric emptying study. Methods:, Twenty-two patients who had undergone surgical operation and 131I ablation for thyroid cancer participated in solid meal gastric emptying studies before the withdrawal of thyroxine and then again 4 weeks after the withdrawal of thyroxine. Eleven patients had an additional gastric emptying study at 6 weeks after withdrawal of thyroxine. Gastric emptying curves and emptying parameters were calculated. Student's paired t -test was used for statistical analysis of data for all cases between the baseline and at 4 weeks after withdrawal. An additional repeated measure anova with multiple comparisons was performed on data between baseline, 4 weeks and 6 weeks after withdrawal for the other 11 patients. All P values presented are two-tailed and the significance level is 0.05. Results:, Hypothyroidism status was confirmed by the marked change of the serum thyroxine and thyroid-stimulating hormone 4 weeks and 6 weeks after withdrawal of the thyroxine replacement (P < 0.001). The gastric half-emptying time and emptying rate changed significantly after short-term severe thyroid hormone deficiency (P < 0.005). However, the length of the lag phase did not have a statistically significant change at 4 weeks or 6 weeks after withdrawal of the thyroxin replacement (P = 0.219 and 0.142). Conclusions:, Hypothyroidism following the withdrawal of the thyroxine replacement in thyroid cancer patients preparing for 131I cancer work-up can significantly prolong gastric half-emptying time and emptying rate. [source] The effects of thyroxine replacement on the levels of serum asymmetric dimethylarginine (ADMA) and other biochemical cardiovascular risk markers in patients with subclinical hypothyroidismCLINICAL ENDOCRINOLOGY, Issue 2 2005Omer Ozcan Summary Background, The relationship between subclinical hypothyroidism (SH) and cardiovascular disease (CVD) is still under debate. The purpose of the present study was to evaluate plasma total homocysteine (tHcy), high sensitive C-reactive protein (hsCRP), small dense low-density lipoprotein (sdLDL), l -arginine and asymmetric dimethylarginine (ADMA) concentrations and their relationship to nitric oxide (NO) production, measured as plasma nitrite-plus-nitrate (NOx) concentration, in patients with SH before and after thyroxine replacement therapy and compared with control group values. Design, Eighty-four women with SH and 33 healthy women as controls matched to the patient group for sex, age and body mass index (BMI), were enrolled in this study. Lipoprotein profile, tHcy, hsCRP, sdLDL, ADMA, l -arginine and NOx were measured in pre- and post-treatment blood samples. Results, The pretreatment total cholesterol (TC), LDL-C, hsCRP, ADMA and l -arginine levels were significantly higher and NOx levels were lower than in the control group. After treatment, hsCRP, ADMA and l -arginine levels were significantly reduced and sdLDL and NOx levels were significantly increased. Conclusion, The present study demonstrated an elevation of hsCRP and ADMA plasma levels of patients with SH associated with a reduction in NO production, which may contribute to some cardiovascular alterations. The elevated ADMA and hsCRP levels were reduced after thyroxine replacement. Also the sdLDL levels of SH patients were found to be lower than the control group values whereas TC and LDL were elevated. Even though we found an elevation in sdLDL levels after treatment, those values were still not higher than in the control group. [source] Recombinant human TSH testing is a valuable tool for differential diagnosis of congenital hypothyroidism during l -thyroxine replacementCLINICAL ENDOCRINOLOGY, Issue 2 2003Laura Fugazzola Summary objective The differential diagnosis of congenital hypothyroidism (CH) is aimed to distinguish transitory from permanent forms, to optimize l-thyroxine (l-T4) therapy to replacement or TSH-suppressive regimens, and to reach accurate definition of the clinical and biochemical phenotype for subsequent genetic investigations and counselling. Therefore, l -T4 therapy is presently withdrawn in most instances and investigations are performed in a disturbing hypothyroid state. design The availability of recombinant human TSH (rhTSH) prompted us to assess its efficacy in the differential diagnosis of CH during l-T4 therapy. patients and measurements Eight adult patients with permanent CH remained on l -thyroxine and underwent a new protocol for rhTSH (Thyrogen®) testing with injections [4 g/kg/day intramuscularly (i.m.)] at days 1, 2 and 3. At day 3, 123I was administered and uptake obtained after 2 and 24 h. Serum TSH and thyroglobulin (Tg) levels were measured at days 1,4. Neck ultrasound was carried out in all cases. results Serum TSH reached levels > 20 mU/l at day 2 and remained above 30 mU/l on days 3 and 4. Stimulation of Tg levels was seen in five patients with peak at day 4. Lingual thyroid was documented at scintigraphy (TS) in three Tg-responsive patients who were previously diagnosed as having thyroid agenesia. In one patient with dyshormonogenesis and high Tg, TS confirmed the presence of goitre with positive perchlorate test. TS was negative in the remaining four cases. All tests indicated complete agenesia in one, whereas a minimal Tg response was marker of nearly complete agenesia in another. The last two TS-negative patients had hypoplastic glands at ultrasound, and refractoriness to TSH stimulation was confirmed by absent Tg response. conclusions We report the first application of rhTSH for differential diagnosis of patients with permanent CH, avoiding the undesirable transient hypothyroidism consequent to l-T4 withdrawal. The data obtained led to the change of the diagnosis at presentation in 4/8 patients and to a more accurate description of the clinical picture in all patients. The proposed protocol has been proved to cause Tg increases even in the presence of small amounts of responsive thyroid cells. The rhTSH testing led to the desired disease characterization, thus allowing specific management and targeted genetic analyses. [source] | ||||||||||