International Journal of Endocrinology and Metabolism
Volume:1 Issue: 1, Mar 2003

Diagnostic confusion results when subnormal free T4 values are reported in nonthyroidal illness (NTI) when a variety of free thyroxine index or analogue techniques are used to estimate free thyroxine levels. We tried to correct the changes in free thyroxine assessments by a mathematical method in nonthyroidal illness (NTI). Serum albumin was used to correct the measured hormone concentration by mathematical formulas. The study included 56 patients with acute and chronic systemic illnesses and control groups. Total T4 (TT4), total T3 (TT3), free T4 and free T3 by analogue method (FT4A and FT3A), free T4 by back titration (FT4B), TSH-IRMA, reverse T3, T3 Resin Uptake (T3RU), TBG, albumin and total serum proteins (TSP) were measured. Free T4 index (FT4I) and T4/TBG ratio (T4TBGR) were calculated. Mathematical correction for each hormone was done through equations based onpatient''s original hormone level and albumin concentration. As an example, the formula forcorrection of FT4A was: expected FT4A = (patient''s FT4A) - X (patient''s albumin) + Y;X = 1.11 × [(mean FT4A in normal subjects) ÷ (mean albumin in normal subjects)];Y = 1.11 × (mean FT4A in normal subjects). The decrease in albumin and TSP resulted in a decrease in TT4 and TT3, FT4A and FT3A in NTI, but it had no significant effect on FT4B. Mathematical correction resulted in an increase in sensitivity of FT4A from 55.4 to 96.4%, FT4B from 94.6 to 100%, T4TBGR from 80.4 to 98.2%, and FT4I from 69.6 to 100%, indifferentiating NTI from hypothyroidism. The specificity of tests remained unchanged. Thecorrections did not affect normal, hypothyroid, and hyperthyroid controls. Mathematical correction increased sensitivity of tests, which assess free T4 directly or indirectly, in differentiating NTI from hypothyroidism. NTI has been reported as the most common cause of errors reported in thyroid function tests so mathematical correction coul significantly increase overall accuracy of free T4 assessments.

Following bone marrow transplantation (BMT), life expectancy of many patients increases, necessitating medical follow up, especially function of the endocrine gland. Previous studies have shown that endocrine dysfunctions are caused not only by total body irradiation, but also by cytotoxic conditioning regimens. 46 patients (12 F, 34 M), aged 1.5-49 years were evaluated for thyroid (T3, T4, TSH, T3RU, FTI, Anti Tg-Ab, Anti TPO-Ab), parathyroid (Ca, Alkp, PTH), gonad function (LH, FSH, E2, progesterone in females and semen analysis in males) and function of β-cells of pancreas by O.G.T.T (in 12 major thalassemicpatients) before and 3, 6, 12, 24 months after BMT, by the “Little” Busulfan-Cyclophosphamide conditioning regimen. There are no differences between results of clinical examinations and laboratory tests of pre and post BMT function of thyroid or parathyroid and calcium metabolism. The function of leydig cells was normal in 11 adult men (G5P5) before and 3, 6, 12 months after BMT, but injury of germinal cells (oligo- or azospermia) before and 12 months after BMT was seen. There is no relation between FSH and injury of germinal cells. Development of puberty was normal in 5 boys (G2P2 or G3P3) before and one year after BMT Primary hypogonadism was induced in 4 females (B5P5) after BMT In one 14 year-old female, regular menstruation continued 2 years after BMT In one girl (P1B1 before BMT) ovarian failure developed 12 months after BMT. Function of β- cells in thalassemic patients (Ferritin>1000 before BMT) before and after BMT was normal. One year after B.M.T, the chemotherapy-conditioning regimen per se did not affect function of thyroid or parathyroid gland, but ovarian failure and germinal cells injuries developed (without effect on leydig cells). BMT had no effect on the function of β- cells of the pancreas.

The present study was designed to assess the influence of mode of delivery on fetal pituitary-thyroid axis. The endocrine profile (umbilical venous plasma) of three groups of term infants was compared immediately after delivery. Samples were taken after 30 vaginal deliveries, 30 emergency cesarean sections during labor and 30 elective cesarean sections before labor. The study was performed in the Kowsar Hospital in Qazvin. The samples were matched based on maternal age, parity and gestational age and none of them had previous history of medical complications. Measurements of TSH and thyroid hormone levels were performed using immunoenzymometric and radioimmuno assays, respectively. Mean cord plasma TSH level of vaginal and emergency cesarean section was significantly lower than that of the elective cesarean section (p<0.0001; 3.3±1.8, 9.0±3.2 and 12.1±6.4 μU/mL, respectively). Mean concentrations of T4 and T3 were significantly higher in the elective cesarean section as compared with the emergencycesarean section and vaginal deliveries (p<0.05; 8.5±1.3, 7.4±2.4 and 7.4±1.3 μg/dL for T4 and 76±12, 62±20 and 51±16 ng/dL for T3, respectively). These results suggest that labor may reduce plasma thyrotropin and thyroid hormone concentrations at birth.

THe study was designed to investigate the influence of hypothermia on thyroid gland function and its role in metabolic balances. Superficial hypothermia, bringing the body temperature to 25°C, was induced in ten rats (albino, Wistar race) with a mean age of 8 months. Serum levels of FT3, FT4, T3, T4, and TSH were determined before and just after hypothermia, repeated every 24hours for 4 days. Hormone levels, measured by radioimmunoassay, changed during the study. On different days of study, TSH levels altered, although not significantly, from basal values. Other hormones, decreased significantly after hypothermia, except for T3 that increased significantly on day 3 compared to basal levels. FT3 and FT4 showed the most decrease. Serum T4 level decreased significantly until 48 hours following hypothermia, after which the decrease was not significant and thereafter began to riseand return to basal levels. Although the body temperature of rats decreased significantly after hypothermia, it increased the day after hypothermia and reached closer to body basal temperature (37°c) after 96 hours. Our findings indicate reduced activity of the thyroid gland and hypothalamuspituitary axis during hypothermia, this being more prominent in the thyroid gland.

ix patients with adrenal myelolipoma (AML) are reported. They included 3 men and 3 women with mean age (+ SD) of 42.3 + 10.9 yrs ranging from 26 to 60 yrs. Four patients were symptomatic, while the other 2 had no symptoms. Detection of AML was‘incidental’ in 4 patients while being investigated for non-adrenal symptoms (pain bdomen in 2 and work-up for renal disease in 2), while the remaining 2 patients, one (#5) with congenital adrenal hyperplasia due to 21 alpha-hydroxylase deficiency had myelolipomatous alterations in the adrenal gland and the other (#6) had detectionof AML during work-up for hypertension. All patients were obese (BMI > 27), four werehypertensive and one had type 2 diabetes. Imaging was suggestive of AML in five of themHowever, in one case radiological diagnosis of angiomyolipoma of the kidney was considered. Interestingly, the right adrenal was involved in five of them. Four patients underwent adrenalectomy in view of symptoms and size of the mass, while the other 2 are under follow-up. Cyto/histopathology was consistent with AML in all these patients.However, in one case myelolipomatous alterations were noted in the background ofadreno-cortical tumor. No recurrence or alterations in tumor size was noted during thefollow-up period ranging from 6 months to 4 years. A brief review of literature is alsopresented.