BACKGROUNDMaternal thyroid dysfunction is common during pregnancy, and physiological changes during pregnancy can lead to the overdiagnosis of hyperthyroidism and misdiagnosis of hypothyroidism with nongestation-specific reference intervals. Our aim was to compare sequential with nonsequential methods for the evaluation of thyroid function in pregnant women.

METHODSWe tested pregnant women who underwent their trimester prenatal screening at our hospital from February 2011 to September 2012 for serum thyroid stimulating hormone (TSH) and free thyroxine (FT4) using the Abbott and Roche kits. There were 447 and 200 patients enrolled in the nonsequential and sequential groups, respectively. The central 95% range between the 2.5th and the 97.5th percentiles was used as the reference interval for the thyroid function parameter.

RESULTSThe nonsequential group exhibited a significantly larger degree of dispersion in the TSH reference interval during the 2nd and 3rd trimesters as measured using both the Abbott and Roche kits (all P < 0.05). The TSH reference intervals were significantly larger in the nonsequential group than in the sequential group during the 3rd trimester as measured with both the Abbott (4.95 vs. 3.77 mU/L, P < 0.001) and Roche kits (6.62 vs. 5.01 mU/L, P = 0.004). The nonsequential group had a significantly larger FT4 reference interval as measured with the Abbott kit during all trimesters (12.64 vs. 5.82 pmol/L; 7.96 vs. 4.77 pmol/L; 8.10 vs. 4.77 pmol/L, respectively, all P < 0.05), whereas a significantly larger FT4 reference interval was only observed during the 2nd trimester with the Roche kit (7.76 vs. 5.52 pmol/L, P = 0.002).

CONCLUSIONSIt was more reasonable to establish reference intervals for the evaluation of maternal thyroid function using the sequential method during each trimester of pregnancy. Moreover, the exclusion of pregnancy-related complications should be considered in the inclusion criteria for thyroid function tests.

Female ; Humans ; Pregnancy ; physiology ; Reference Values ; Thyroid Gland ; physiology ; Thyrotropin ; blood ; Thyroxine ; blood

This study was to determine the daily fluctuation of serum thyroxine (tT4), free thyroxine (fT4), 3,5,3'-triiodothyronine (T3) concentrations in healthy dogs. Thyroid function of these dogs was evaluated on the basis of results of TSH response test. Samples for the measurement of serum tT4, fT4, and T3 concentrations were obtained at 3- hour intervals from 8 : 00 to 20 : 00. Serum tT4, fT4, and T3 concentrations were measured by the enzyme chemiluminescent immunoassay (ECLIA). Mean T3 concentrations had no significant differences according to the sample collection time during the day. Mean tT4 and fT4 concentrations at 11 : 00 were 3.28 +/- 0.86 microgram/dl and 1.30 +/- 0.37 ng/dl, respectively and mean tT4 and fT4 at 14:00 were 3.54 +/- 1.15 microgram/dl and 1.35 +/- 0.12 ng/dl, respectively. These concentrations were significantly high compared with tT4 and fT4 concentrations at 8:00, which were 1.75 +/- 0.75 microgram/dl and 0.97 +/- 0.25 ng/dl, respectively (p < 0.05). According to the sample collection time, mean tT4 and fT4 concentrations changed with similar fluctuation during the day. Based on these results, it was considered that measurement of serum tT4 and fT4 concentrations from 11 : 00 to 14 : 00 might more easily diagnose the canine hypothyroidism in practice.
Animals ; Circadian Rhythm/physiology ; Dogs/*blood ; Female ; Immunoenzyme Techniques/veterinary ; Male ; Thyroid Function Tests/veterinary ; Thyroxine/*blood ; Triiodothyronine/*blood

BACKGROUNDThe importance of diagnosis of thyroid dysfunction during pregnancy has been widely recognized. Our study was designed to compare two different detection reagents between Abbott and Roche and to establish the gestational related reference intervals for thyroid function tests (TFT) in Chinese women and to assay the reference ranges with the American Thyroid Association recommended standard.

METHODSSerum samples were collected from 693 normal pregnant Chinese women and divided into five groups according to their gestational age: 9-13, 16-20, 24-28, 32-34 and 37-40 weeks. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels were determined by two different detection reagents: Abbott Architect I 2000 and Roche Cobas Elecsys 600. The reference ranges of the TFT indexes were calculated according to the National Academy of Clinical Biochemistry (NACB). The 2.5th and 97.5th percentiles of each stage were calculated, and the results were analyzed by one-way analysis of variances, t-test, and Spearman correlation analysis.

RESULTSThyroid hormone levels varied greatly among different gestational stages. TSH levels, as assessed via two different TSH ELISA kits showed consistent changing pattern during pregnancy and displayed linear correlation (P < 0.001). In 9-13 gestational weeks, TSH levels were significantly lower than that of other groups; and in 37-40 gestational weeks, it was higher than that of other groups (all P < 0.001). TSH reference ranges determined by Roche detection reagent in each group were higher than those by Abbott detection reagent (P < 0.01 respectively). FT4 levels were higher in 9-13 gestational weeks than that of other groups (P < 0.001). FT4 levels determined by Roche reagent were higher than Abbott reagent in 9-13 weeks, (P < 0.001), and lower in 24-28 and 37-40 weeks (P < 0.001 and P = 0.016, respectively). The TSH level was correlated with FT4 levels in 9-13 gestational weeks by detection reagents (for Abbott reagent, r=-0.319 for FT4 P < 0.001; for Roche reagent, r=-0.352 for FT4, P <0.001).

CONCLUSIONAccurate evaluation of TFT in pregnant women should be based on the gestational-related reference intervals in Chinese population, and different detection reagents should also establish their own reference intervals.

Adult ; Female ; Gestational Age ; Humans ; Luminescent Measurements ; Pregnancy ; physiology ; Reference Values ; Thyroid Function Tests ; Thyroid Gland ; physiology ; Thyrotropin ; blood ; Thyroxine ; blood

OBJECTIVETo study the effect of chronic rapid eye movement sleep deprivation on energy metabolism, FT3, FT4 in serum.

METHODSRapid eye movement sleep deprivation of rats were deprived by flower pot, and then the energy metabolism were detected. The FT3, FT4 level in serum was determined by radioimmunoassay kit.

RESULTSRats after sleep deprivation displayed food intake increased from (75.06 +/- 25.37)g/(d x kg) to (122.30 +/- 20.43)g/(d x kg), body weight substantially decreased from (360.89 +/- 43.01) g to (295.97 +/- 37.95) g, body temperature from (37.62 +/- 1.12) degrees C up to the first (39.00 +/- 0.87) degrees C and then reduced to (37.72 +/- 0.84) degrees C, the basal metabolism rate increased significantly from (1.69 +/- 0.36) mlO2/(g x h) to (2.40 +/- 0.09) mlO2/(g x h), compared with the control group( P < 0.05). Sleep deprivation also resulted significantly lower serum thyroxine levels in comparison with the control, serum free triiodothyronine (FT3) level reduced from (3.38 +/- 0.88) pmol/L to (2.38 +/- 0.83) pmol/L, then free thyroxine(FT4) decreased from (14.62 +/- 3.62) pmol/L to (8.26 +/- 2.80) pmol/L (P < 0.05).

CONCLUSIONRapid eye movement sleep deprivation can change energy metabolism remarkable, as well as the alteration of FT3, FT4 levels in serum.

Animals ; Energy Metabolism ; physiology ; Male ; Rats ; Rats, Wistar ; Sleep Deprivation ; blood ; metabolism ; Sleep, REM ; physiology ; Thyroxine ; blood ; Time Factors ; Triiodothyronine ; analogs & derivatives ; blood

BACKGROUND: Systemic inflammatory reaction syndrome (SIRS) describes the systemic inflammatory process and can be seen following a wide variety of insults. This is the leading cause of morbidity and mortality for patients admitted to the ICU. The arterial keton body ratio (AKBR), serum lactate level and the thyroid hormones, thyroid stimulation hormone (TSH), thyroxine (T4), free thyroxine (FT4) and triiodothyronine (T3) deteriorate in critically ill patients with a poor prognosis. The APACHE (Acute Physiology, and Chronic Health Evaluation) III and multiple organ failure (MOF) score have been known as good prognostic predictors in the ICU. The object of this study was to compare the AKBR, lactate and thyroid hormone levels, and the APACHE III and MOF score between the survivors (SV) and nonsurvivors (NSV) and the correlation among the above predictors. METHODS: 35 patients with no known thyroid or liver disease who were admitted to the SICU with the criteria of SIRS were selected. Arterial blood was drawn for the AKBR, and the lactate and thyroid hormones studies. The APACHE III and MOF scorings were done in the first 24 hours of SICU admission. RESULTS: There were no significant difference between SV and NSV except APACHE III (SV: 68.7 24.6, NSV; 92.9 27.6). There were significant correlations between the APACHE III and MOF score (R = 0.688, P<0.01), APACHE III and lactate (R = 0.575, P<0.01), and MOF score and lactate (R =0.483, P<0.01). Thyroid hormones had positive correlations among themselves only. CONCLUSIONS: We conclude that APACHE III is the only good predictor of mortality. The APACHE III, MOF score, and lactate level show good correlations indicating the severity in condition of the ICU patients.
APACHE ; Critical Illness ; Humans ; Lactic Acid ; Liver Diseases ; Metabolism* ; Mortality ; Multiple Organ Failure ; Physiology ; Prognosis ; Survivors ; Thyroid Gland* ; Thyroid Hormones* ; Thyroxine ; Triiodothyronine

The aim of the present study is to investigate the alterations of cardiac hemodynamics, sodium current (I(Na)) and L-type calcium current (I(Ca-L)) in the cardiomyopathic model of rats. The model of cardiomyopathy was established by intraperitoneal injection of L-thyroxine (0.5 mg/kg) for 10 d. The hemodynamics was measured with biological experimental system, and then I(Na) and I(Ca-L) were recorded by using whole cell patch clamp technique. The results showed that left ventricular systolic pressure (LVSP), left ventricular developed pressure (LVDP), +/-dp/dt(max) in cardiomyopathic group were significantly lower than those in the control group, while left ventricular end-diastolic pressure (LVEDP) in cardiomyopathic group was higher than that in the control group. Intraperitoneal injection of L-thyroxine significantly increased the current density of I(Na) [(-26.2+/-3.2) pA/pF vs (-21.1+/-6.3) pA/pF, P<0.01], shifted steady-state activation and inactivation curves negatively, and markedly prolonged the time constant of recovery from inactivation. On the other hand, the injection of L-thyroxine significantly increased the current density of I(Ca-L) [(-7.9+/-0.8) pA/pF vs (-5.4+/-0.6) pA/pF, P<0.01)], shifted steady-state activation and inactivation curves negatively, and obviously shortened the time constant of recovery from inactivation. In conclusion, the cardiac performance of cardiomyopathic rats is similar to that of rats with heart failure, in which the current density of I(Na) and especially the I(Ca-L) are enhanced, suggesting that calcium channel blockade and a decrease in Na(+) permeability of membrane may play an important role in the treatment of cardiomyopathy.
Animals ; Calcium Channels, L-Type ; metabolism ; Cardiomyopathies ; chemically induced ; metabolism ; physiopathology ; Hemodynamics ; physiology ; Male ; Myocardium ; metabolism ; Patch-Clamp Techniques ; Rats ; Rats, Sprague-Dawley ; Sodium Channels ; metabolism ; Thyroxine

BACKGROUNDGrowing evidence links alternation of the thyroid function to the pathogenesis and progression of Alzheimer disease (AD). However, only a few studies evaluate the association between thyroid hormone levels and neuropsychiatric manifestations in patients with AD. This study aimed to investigate the relationship of thyroid hormone levels and neuropsychiatric symptoms in euthyroid patients with AD.

METHODSForty patients with AD (26 women and 14 men), with no prior AD treatment within 4 weeks before study entry, were evaluated on their thyroid status (total triiodothyronine (TT3), total thyroxine (TT4), and thyroid-stimulating hormone (TSH)), cognition (Mini-Mental State Examination (MMSE) and Alzheimer's disease Assessment Scale-Cognitive Subscale (ADAS-cog)), neuropsychiatric symptoms (Neuropsychiatric Inventory (NPI)) and depression (Hamilton Rating Scale for Depression (HAMD(17))). The unique relationship between thyroid hormones and cognitive function and mood was examined with multivariate linear regression analyses. The thyroid status between the neuropsychiatric symptoms group and the non-neuropsychiatric symptoms group was examined with independent-samples t-test.

RESULTSIn euthyroid AD patients with agitation and irritability has lower TSH serum level than those without these symptoms (t = -2.130, P < 0.05; t = -2.657, P < 0.05); and core score of HAMD is significantly associated with the serum level of TSH (β = 0.395, P < 0.01). There is no significant association between thyroid hormone levels and cognition (MMSE, ADAS-cog and its subscale score).

CONCLUSIONThere might be a relationship between thyroid hormone levels and the neuropsychiatric symptoms in euthyroid patients with AD.

Aged ; Aged, 80 and over ; Alzheimer Disease ; blood ; metabolism ; Cognition ; physiology ; Female ; Humans ; Male ; Middle Aged ; Multivariate Analysis ; Thyroid Gland ; metabolism ; Thyrotropin ; blood ; Thyroxine ; blood ; Triiodothyronine ; blood

Prolonged administration of anterior hypophyseal, adrenocortical, or thyroid hormones is known to cause degeneration, degranulation and necrosis of the beta-cells in the Langerhans islets of the pancreas. However, the effects of extirpation of these endocrine glands upon the Langerhans islets has not been reported, a1though it is known that removal of any of these glands bring about hypoglycemia, decreased tissue uptake of glucose, and increased tissue sensitivity to insulin. The present investigation is studies of the morphologic alterations of the beta-cells in the Langerhans islets following hypophysectomy, adrenalectomy, or thyroidectomy in rats. Hypophysectomy, adrenalectomy, and thyroidectomy, all induce similar morphologic alterations in the beta-cells of the islets. These consist of increased beta-cell population, the accumlnation of beta-granules, and atrophy of the individual betacell. Therefore, these changes are considered to be not specific following the withdrawal of specific hormones but a common effect of the hypoglycemia due to removal of the hypophysis, adrenals, or thyroid glands. A similar common degeneration of the beta-cells due to hyperglycemia occurs when hormones of these endocrine glands are given excessively.
Adrenal Cortex Hormones/physiology ; Adrenalectomy* ; Animal ; Atrophy/etiology ; Blood Glucose ; Diabetes Mellitus/etiology ; Glycogen/metabolism ; Hyperglycemia/etiology ; Hypoglycemia/etiology ; Hypophysectomy* ; Insulin/secretion ; Islets of Langerhans/pathology* ; Liver Glycogen/metabolism ; Muscles/metabolism ; Myocardium/metabolism ; Necrosis/etiology ; Rats ; Staining and Labeling ; Thyroidectomy* ; Thyroxine/physiology

OBJECTIVEAlthough several reports documented the association of congenital hypothyroidism (CH) and left ventricular (LV) function in infants or neonates, right ventricular (RV) function in neonates with CH has not been previously studied. The aim of the present study was to assess RV function in neonates with CH before and after thyroxine substitution therapy by quantitative tissue velocity imaging (QTVI) and tissue tracking imaging (TTI).

METHODSFifty-two neonates aged 18-28 days (25 males and 27 females) with CH and 35 healthy neonates aged 18-28 days (16 males and 19 females) were studied by QTVI, TTI as well as conventional pulsed-wave Doppler echocardiography (PWD). The standard apical four-chamber view for long-axis motion of the right ventricle was used for echocardiographic evaluation. Peak systolic displacement (D), peak systolic velocity (Vs), peak early (Ve) and late (Va) diastolic velocity of tricuspid annule were measured, Ve/Va ratio was calculated as well. Transtricuspid flow velocity during early diastole (E) and late diastole (A) were also measured by pulsed-wave Doppler echocardiography. PWD and E/A ratio were calculated too. For each neonate, serum hormone levels of TSH, TT(3), TT(4), FT(3) and FT(4) were measured with a standard chemiluminescent immunoassay. After 1 month of levothyroxine (L-T(4)) substitution therapy in CH neonates, all the echocardiographic evaluations and biochemical tests were re-evaluated. Correlation analysis was also made between serum thyroid hormones levels and right ventricular function.

RESULTSThe indices of right ventricular diastolic function by PWD (E and E/A ratio) in CH group were (45 +/- 10) cm/s and (0.8 +/- 0.3), respectively. Compared with controls, E and E/A ratio in CH neonates were significantly lower (P < 0.001, respectively), while A did not differ between the two groups (P > 0.05). QTVI and TTI showed that right diastolic function (Ve and Ve/Va ratio) as well as right systolic function (Vs and D) in CH group were (3.69 +/- 1.38) cm/s, (0.74 +/- 0.19) cm/s, (4.38 +/- 0.63) cm/s and (0.52 +/- 0.12) cm, respectively. CH neonates had significantly lower Ve, Ve/Va ratio, Vs and D of tricuspid annular velocity (P < 0.001, respectively), whereas there was no significant difference in Va between the two groups (P > 0.05). After 1 month of substitutive therapy, CH neonates showed a significant increase of Ve, Ve/Va ratio, Vs, D, E, and E/A ratio, (6.92 +/- 1.86) cm/s, (1.13 +/- 0.22), (5.92 +/- 1.03) cm/s, (0.78 +/- 0.17) cm, (61 +/- 10) cm/s and (1.1 +/- 0.4), respectively (P < 0.001). Those parameters were positively correlated with serum TT(3), TT(4), FT(3) and FT(4) levels (P < 0.01, respectively), and were negatively correlated with serum TSH levels (P < 0.01, respectively).

CONCLUSIONSOur findings suggest that neonates with CH are associated with right ventricular subclinical systolic and diastolic dysfunction, which can be reversed by early L-T(4) substitution therapy. QTVI and TTI are valuable methods to evaluate right ventricular function in neonates. Systolic and diastolic velocities of the tricuspid annulus measured by QTVI and TTI are useful and accurate to assess RV function in neonates.

Adult ; Blood Flow Velocity ; Child, Preschool ; Congenital Hypothyroidism ; physiopathology ; Diastole ; drug effects ; physiology ; Echocardiography ; Echocardiography, Doppler, Pulsed ; Female ; Heart Ventricles ; drug effects ; physiopathology ; Humans ; Male ; Systole ; drug effects ; physiology ; Thyrotropin ; pharmacology ; Thyroxine ; blood ; pharmacology ; Tricuspid Valve ; physiopathology ; Ventricular Function, Left ; drug effects ; physiology ; radiation effects ; Ventricular Function, Right ; drug effects ; physiology

OBJECTIVETo explore the effects of thyroid hormone (TH) on cardiac function and peripheral lymphocyte beta-adrenoceptors (beta-ARs) of patients with chronic congestive heart failure (CHF).

METHODSTwenty-eight patients with class III or IV advanced CHF due to dilated cardiomyopathy (DCM) or ischemic cardiomyopathy (ICM) were randomly divided into groups A and B. L-thyroxine (L-T(50)) was administered to group B. Exercise tolerance, chest X-rays, and echocardiographic parameters were obtained before and after one month of treatment, Ficoll-hypaque solution was used to separate peripheral lymphocytes, and (125)I-pindolol radioligand binding was used to measure beta-AR levels in peripheral lymphocytes.

RESULTSL-T(50) therapy improved cardiac output [CO, (2.98 +/- 0.31)L/min vs (3.24 +/- 0.28) L/min, P < 0.01], left ventricular ejection fraction (LVEF, 26.21% +/- 3.21% vs 37.93% +/- 9.01%, P < 0.01), and decreased isovolumetric relaxation time (IVRT, 0.12 +/- 0.04 vs 0.10 +/- 0.02, P < 0.01). Serum TH levels and the maximal number of beta-AR binding sites (beta(max)) in peripheral lymphocytes were lower in patients with CHF than in normal healthy people, but L-T(50) administration induced a beta-AR up-regulation on peripheral lymphocyte surfaces. L-T(50) was well tolerated without episodes of ischemia or arrhythmia. There was no significant change in heart rate or metabolic rate.

CONCLUSIONTH administration improves cardiac function and beta-AR expression in peripheral lymphocytes of patients with CHF.

Adult ; Aged ; Blood Pressure ; drug effects ; Chronic Disease ; Echocardiography ; Female ; Heart ; drug effects ; physiology ; Heart Failure ; physiopathology ; Heart Rate ; drug effects ; Humans ; Lymphocytes ; chemistry ; Male ; Middle Aged ; Receptors, Adrenergic, beta ; analysis ; Thyroxine ; pharmacology