The effect of serum free fatty acid on serum free thyroid hormone fractions in low T3 syndrome

We studied the role of serum free fatty acid (FFA) in the elevation of serum dializable fraction of T4 (DFT4) and evaluated the serum free T4 (FT4) level in low T3 syndrome. Serum DFT4 and DFT3 were measured by equilibrium dialysis method with phosphate buffer, and serum FFA concentration was obtained by gas chromatography. In patients with nonthyroidal systemic illnesses who showed reduced serum total T3 (TT3) and normal total T4 (TT4) (low T3 group, TT3 48 +/- 14 ng/dl, n = 10), mean (+/- SD) DFT4 value (0.032 +/- 0.05%) was significantly higher than that of the group of systemic illnesses with normal TT3 and TT4 (normal T3 group, TT3 79 +/- 7 ng/dl, n = 10). Mean TT4 value of low T3 group (6.5 +/- 1.0 micrograms/dl) was lower than that of normal T3 group (8.6 +/- 2.4 microgram/dl, p less than 0.02). There was no difference in mean absolute FT4 (AFT4) value between the two groups (2.07 +/- 0.46 vs 2.19 +/- 0.53 ng/dl). On the other hand, there was no significant difference in DFT3 value between the groups (0.274 +/- 0.043 vs 0.247 +/- 0.035%), and mean AFT3 of low T3 group (1.29 +/- 0.39 pg/ml) was low than that of normal T3 group (1.92 +/- 0.26 pg/ml, p less than 0.01). In cases of low and normal T3 groups (n = 20), serum thyroxine binding globulin (TBG) concentration had a negative correlation with DFT3 (r = -0.707, p less than 0.001), but not with DFT4. Although there were no significant differences in serum albumin and TBG concentrations between the two groups, the mean serum total FFA concentration and molar ratio of FFA to albumin in low T3 group (579 +/- 249 microM and 1.31 +/- 0.61) were significantly higher than those in normal T3 group (345 +/- 170 microM and 0.75 +/- 0.32, p less than 0.05 and less than 0.025, respectively). All of FFA concentrations in low T3 group, especially oleate, were higher than those in normal T3 group. Moreover, the higher the total FFA concentration was, the greater was the percent fraction of oleate. DFT4 values were significantly increased by the addition of 1 mM oleate to the sera of low T3 group, and this effect was more marked in the sera of the patients with lower albumin concentration.(ABSTRACT TRUNCATED AT 400 WORDS)     

Fatty acid induced changes in circulating total and free thyroid hormones: in vivo effects and methodological artefacts

Elevated levels of nonesterified fatty acids (NEFA) are frequently found in acute illnesses, and they may contribute to changes in serum thyroid hormone concentrations in nonthyroidal illnesses (NTI) by displacing protein bound hormones. We therefore examined the effects of low and raised plasma NEFA levels on circulating total and free thyroxine (TT4 and FT4) and triiodothyronine (TT3 and FT3) concentrations, the Free T4 Index (FT4I) and TSH, in a randomized crossover study in 10 normal subjects. Subjects ate either a high carbohydrate breakfast (low NEFA protocol) or a high fat breakfast followed by an iv injection of 1000 u heparin (high NEFA protocol). Possible biological effects of changes in FT4 and FT3 were evaluated by a 200 micrograms iv TRH test. Free T4 and T3 were measured by a direct analogue method (AFT4 and AFT3). In a similar high NEFA study, but without TRH, FT4 was also measured by equilibrium dialysis (DFT4) and a 2-step RIA method (2-step FT4). Acute elevations of plasma NEFA from 0.67 +/- 0.08 mmol/L to a peak of 2.6 +/- 0.54 mmol/L resulted in a prompt reciprocal fall of mean TT4 (-8.7%, p less than 0.01), AFT4 (-30%, p less than 0.005) and TT3 (-11.5%, p less than 0.01) and AFT3 (-16%, p less than 0.005); DFT4 rose significantly from 23.7 +/- 1.9 pmol/L to 33.0 +/- 3.7 pmol/L (+39%, p less than 0.025) and 2-step FT4 rose by 16% (p less than 0.05). TSH levels declined consistently from 3.3 +/- 0.5 mIU/L to 2.6 +/- 0.4 mIU/L (p less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum angiotensin-converting enzyme in severe nonthyroidal illnesses associated with low serum thyroxine concentration

We evaluated serum angiotensin-converting enzyme levels as an index of thyroid hormone action in severe systemic illness. Angiotensin-converting enzyme was elevated in hyperthyroid patients (37.3 +/- 3.2 U/mL, p less than 0.01) and depressed in hypothyroid patients (17.9 +/- 1.4 U/mL, p less than 0.05). Compared with normal controls (22.6 +/- 1.6 U/mL), patients in an intensive care unit with free thyroxine index greater than 5.0 had normal angiotensin-converting enzyme levels (19.1 +/- 2.5 U/mL), but patients with a free thyroxine index less than 5.0 had angiotensin-converting enzyme levels significantly lower than the normal and hypothyroid groups (10.7 +/- 1.0 U/mL, p less than 0.05). A group of patients in an intensive care unit with alcoholic liver disease (known to elevate angiotensin-converting enzyme) and a low free thyroxine index had depressed angiotensin-converting enzyme levels (16.9 +/- 1.5 U/mL, p less than 0.01). A strong correlation was seen in the combined groups of all patients studied between levels of angiotensin-converting enzyme and a free thyroxine index (r = 0.70, p less than 0.01) and free T3 index (r = 0.72, p less than 0.01).     

Thyroid hormones and thermogenesis: a microcalorimetric study of overall cell metabolism in lymphocytes from patients with different degrees of thyroid dysfunction

We used microcalorimetry to measure lymphocyte heat production rate in patients with clinical and laboratory hyperthyroidism (serum TSH decreases, serum FT4 increases, serum FT3 increases), subclinical hyperthyroidism (serum TSH decreases, serum FT1 increases, serum FT3 =), and subclinical hypothyroidism (serum TSH increases, serum FT4 decreases, serum FT3 =) compared with healthy controls (N = 13). The lymphocyte heat production rate was significantly correlated to the free thyroxine level (r = 0.53, p less than 0.01) and to the free triiodothyronine level (r = 0.51, p less than 0.01) when calculated from pooled data for the three patients groups. The hyperthyroid patients (N = 8) had a significantly increased lymphocyte heat production rate, 3.43 +/- 0.25 pW/cell, as compared with 2.31 +/- 0.12 pW/cell in the control group (p less than 0.001). The groups with subclinical hyperthyroidism (N = 7) and subclinical hypothyroidism (N = 9) had lymphocyte heat production rates of 2.14 +/- 0.11 and 2.56 +/- 0.15 pW/cell, respectively, not significantly different from that in the controls. Consistently, there was no significant difference between patients with subclinical hyperthyroidism (N = 5) and controls (N = 5) with regard to lymphocyte energy production as calculated from separately measured oxygen consumption rates in vitro, 1.36 +/- 0.20 and 1.56 +/- 0.12 pW/cell, respectively. Thus microcalorimetry seems to be suitable for studying the influence of thyroid hormones on cellular metabolism. Subclinical thyroid dysfunction does not seem to alter the overall rate of lymphocyte metabolism.     

Effects of severity of chronic obstructive pulmonary disease on thyroid function

To investigate thyroid function in chronic obstructive pulmonary disease (COPD), 46 consecutive patients (35 men) with stable, mild-to-severe disease, having a mean (SD) age of 67 +/- 7 years were studied. All subjects underwent pulmonary function tests (PFTs), arterial blood gas determination, and measurement of serum total thyroxine (TT4), total triiodothyronine (TT3), resin T3 uptake (RT3U), reverse triiodothyronine (rT3), and thyroid-stimulating hormone (TSH) levels. The free thyroxine and free triiodothyronine indexes (FT4I = RT3U/30TT4 and FT3I = RT3U/30TT3, respectively) along with the TT3/TT4 ratio were calculated; the latter was used as a marker of peripheral conversion of thyroxine into triiodothyronine. Interleukin (IL)-6 was also measured to evaluate its potential associations with thyroidal hormone levels. On the basis of forced expiratory volume in 1 second (FEV1), patients were divided in 2 groups: group 1, (FEV1 > or = 50% of predicted, n = 26), with mild-to-moderate COPD and group 2 (FEV1 < 50% of predicted, n = 20) having severe disease. All subjects had normal serum thyroid hormone levels; for the entire COPD population, mean values were 7.80 +/- 1.60 microg/dL for TT4, 1.12 +/- 0.20 ng/mL for TT3, 29.0 +/- 1.88 for RT3U, 7.54 +/- 1.34 for FT4I, 1.07 +/- 0.16 for FT3I, 18.71 +/- 5.89 ng/dL for rT3, and 1.15 +/- 0.6 microU/mL for TSH. Mean TT3/TT4 ratio was 0.14 +/- 0.03. In group 1, TT3, TT4, and TT3/TT4 ratio did not correlate with age, FEV1, PaO2, or inhaled corticosteroids. Similarly, in group 2, TT3 and TT4 were unrelated to the above-mentioned variables; however, there was a strong positive correlation between TT3/TT4 ratio and PaO2 (r =.61, P =.004). IL-6 was within normal limits in all subjects, and it did not correlate with any thyroid hormone either in group 1 or in group 2. It is concluded that in stable COPD, severity of disease through hypoxemia is important in determining the peripheral metabolism of thyroid hormones. Whether this constitutes an adaptation is not known.     

2型糖尿病患者参考范围甲状腺激素与糖尿病肾病的相关性分析

目的:探讨甲状腺功能正常的2型糖尿病患者甲状腺激素与血糖控制及糖尿病肾病(diabetic kidney disease,DKD)的关系。方法:收集240例年龄≥45岁甲状腺功能正常的2型糖尿病患者临床及实验室资料,分析甲状腺激素与血糖控制及DKD的关系。结果:糖化血红蛋白(hemoglobin A1c,HbA1c)分别与总三碘甲状腺原氨酸(total triiodothyronine,TT3)(r=-0.183,P<0.01)、游离三碘甲状腺原氨酸(free triiodothyronine,FT3)(r=-0.221,P<0.01)呈显著负相关。将TT3、FT3、总甲状腺素(total thyroxine,TT4)、游离甲状腺素(free thyroxine,FT4)以四分位法分为4组,以促甲状腺激素(thyroid stimulating hormone,TSH)2.5 mU/L为界分为2组,发现FT3-Q1(2.94~3.52)、FT3-Q2(3.53~3.84)组DKD的患病率分别显著高于FT3-Q4(4.11~4.81)组(FT3-Q1比FT3-Q4χ^2=9.636,P<0.01;FT3-Q2比FT3-Q4χ^2=5.227,P<0.05)。TT3-Q1(0.33~1.27)组DKD的患病率显著高于TT3-Q4(1.54~1.94)组(χ^2=7.557,P<0.01)。多元Logistic回归分析显示,与FT3-Q4组相比,FT3-Q1、FT3-Q2组发生DKD的危险性显著升高[优势比(odds ratio,OR)=5.132,95%可信区间(confidence interval,CI):1.561~16.872,P<0.01;OR=3.775(95%CI:1.131~12.596),P<0.05]。结论:甲状腺功能正常的2型糖尿病患者体内FT3可反映血糖控制情况。参考范围内低水平的FT3与DKD的高患病率显著相关,为DKD的危险因素。     

健康高龄老年人甲状腺激素水平变化趋势分析

目的 探讨80岁以上高龄老年人甲状腺激素水平变化趋势.方法 将602例健康志愿者按年龄分为中青年组(20～59岁)226例、老年组(60～79岁)195例和高龄组(80～102岁)181例,采用化学发光法及放射免疫法测定志愿者血清三碘甲状腺原氨酸(TT3)、甲状腺素(TT4)、游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、促甲状腺激素(TSH)、反T3(rT3)水平,并以SPSS 13.0进行统计分析.结果 老年组与中青年组比较,血清FT3和TT3降低,差异有统计学意义(t值分别为2.793和3.627,均为P＜0.01);高龄组与中青年组比较,TT3、TT4、FT3、TSH、rT3浓度差异有统计学意义(t值分别为10.930、6.065、15.398、-2.933、-5.643,均为P＜0.01);老年组与高龄组比较,TT3、TT4、FT3、TSH、rT3浓度差异有统计学意义(t值分别为8.382、4.298、11.573、-3.383、-5.148,均为P＜0.01).FT3、TT3、TT4浓度与年龄呈负相关(r值分别为-0.51、-0.39、-0.25,P＜0.01),rT3、TSH浓度与年龄呈正相关(r值分别为0.32、0.12,P＜0.01),FT4与年龄无相关.高龄组高于或低于临床正常参考值范围的阳性发生率,在TT3、TT4、FT3、FT4、TSH、rT3中分别为0、0、13.8%、0、6.6%、21%.结论 随着年龄增长,老年人血清甲状腺激素水平及促甲状腺激素均有改变,特别是80岁及以上高龄老年人,血清FT3、rT3、TSH变化更为明显,建议临床设立老年人不同年龄段的血清甲状腺激素正常参考值范围,以减少假阳性的发生率.

Abstract：

Objective To explore the variation tendency of serum thyroid hormone level in the elderly aged over 80 years.Methods The 602 healthy volunteers were divided into 3 groups by age:young group (20-59 years of age,n= 226),elderly group (60-79 years of age,n= 195),and advanced age group (80-102 years of age,n=181).Fasting blood of all persons was harvested,then the levels of serum total triiodothyroxine (TT3),total thyroxine (TT4),free tri-iodothyronine (FT3),free thyroxine (FT4),thyroid-stimulating hormone (TSH) and reverse tri-iodothyronine (rT3) were determined by chemistry luminescence technique and radioimmunoassay.Statistical analysis was made by the software SPSS 13.0.Results The levels of serum FT3 and TT3 were lower in elderly group than in young group (t=2.793,3.627,P=0.005,0.000).There were significant differences in the levels of serum TT3,TT4,FT3,TSH and rT3 between young group and advanced-age group (t =10.930,6.065,15.398,- 2.933,- 5.643,all P = 0.000),also between elderly group and advanced-age group (t= 8.382,4.298,11.573,-3.383,-5.148,all P＜0.001).The levels of serum FT3,TT3 and TT4 were negatively correlated with age (r=- 0.51,-0.39 and -0.25,respectively,all P＜0.01).And the levels of serum rT3 and TSH showed positive relationships with age (r=0.32,0.12,all P＜0.01).There were no relationships between the level of serum FT4 and age.The positive rate of serum TT3,TT4,FT3,FT4,TSH and rT3 concentration beyond the reference value was 0,0,13.8%,0,6.6% and 21% in advanced-age group,respectively.Conclusions The levels of serum thyroid hormone and thyroid-stimulating hormone change with age.The levels of FT3,rT3 and TSH change obviously in the elderly aged over 80 years.It could reduce the false positive rate in clinical practice if normal reference range for serum thyroid hormone levels in different aged elderly is established.     

Effects of growth hormone administration on fuel oxidation and thyroid function in normal man.

In a randomized, double-blind, placebo-controlled, cross-over study, we examined the effects of 14 days of growth hormone (GH) administration (12 IU/d subcutaneously) on energy expenditure (EE), respiratory exchange ratio (RER), and thyroid function in 14 normal adults of normal weight (eight men and six women). EE (kcal/24 h) was significantly elevated after GH administration (2,073 +/- 392, [GH], 1,900 +/- 310, [placebo], P = .01). RER was significantly lowered during GH administration (0.73 +/- 0.04 v 0.78 +/- 0.06, P = .02), reflecting increased oxidation of lipids. Total triiodothyronine (TT3) (nmol/L) and free T3 (FT3) (pmol/L) increased significantly during GH (TT3: 1.73 +/- 0.06 [GH], 1.48 +/- 0.08 [placebo], P = .01; FT3: 6.19 +/- 0.56 [GH], 5.49 +/- 0.56 [placebo], P = .01). Concomitantly, an insignificant decrease in reverse T3 (rT3) (nmol/L) was observed (0.07 +/- 0.01 [GH], 0.15 +/- 0.01 [placebo], P = .08). GH caused a highly significant increase in T3/thyroxine (T4) (x 100) ratio (1.84 +/- 0.12 [GH], 1.37 +/- 0.06 [placebo]). Serum thyrotropin (TSH) was not significantly changed by GH. No changes in total thyroxine (TT4) (nmol/L) (98 +/- 6 [GH], 111 +/- 8 [placebo], P = .40) and free thyroxine (FT4) (pmol/L) (17.4 +/- 1.3 [GH], 18.6 +/- 1.1 [placebo], P = .37) after 14 days of GH administration were observed. In conclusion, 2 weeks of GH administration increases EE and lipidoxidation. This finding may partly be mediated by an increase in peripheral T4 to T3 conversion.     

Clinical study on thyroid hormone levels in tuberculous patients]

The article reported the results of serum total thyroxine (TT4), triiodothyronine (TT3), reverse triiodothyronine (rT3), triiodothyronine resin uptake ratio (T3RU) thyroid stimulating hormone (TSH), free thyroxine index (FT4I), and ratio of T3/rT3 in 103 tuberculous patients. The results showed the levels of serum TT4, TT3 and ratio T3/rT3 in tuberculous patients were lower than those of 50 healthy subjects (total P less than 0.01), rT3, T3RU and TSH were higher than those (total P less than 0.01). FT4I has no significant difference between the two groups (P greater than 0.05).     

AECOPD甲状腺功能变化及与肺功能的关系

目的探讨COPD血清甲状腺激素水平变化及与肺功能的关系。方法用电化学发光法检测100例AECOPD病人、96例COPD稳定患者、100例健康体检者血清三碘甲状腺原氨酸(TT3)、游离三碘甲状腺原氨酸(FT3)、甲状腺素(TT4)、游离甲状腺素(FT4)、超敏促甲状腺激素(h-TSH)。结果 3组间TT3、TT4、FT3、h-TSH检测结果有统计学意义(P<0.05);AECO-PD组和COPD稳定组血清TT3、TT4、FT3、h-TSH水平明显低于对照组(P<0.05);AECOPD组血清TT3、FT3水平明显低于COPD稳定组(P<0.05)。AECOPD组与COPD稳定组中重、极重度亚组血清TT3、TT4、FT3、h-TSH水平明显低于轻、中度亚组(P<0.05)。AECOPD组患者FEV1和FVC与血清TT3、TT4、FT3、h-TSH水平呈显著性正相关(r分别为0.541、0.435、0.419、0.316和0.583、0.502、0.345、0.310,P<0.05)。结论检测甲状腺激素水平有助于COPD病人病情严重程度的判断。     

Basal oxygen uptake: a new technique for an old test

To assess the metabolic effects of T4 and T3, we measured serum total T4 (TT4), free T4 (FT4), total T3 (TT3), TSH, and basal oxygen uptake (VO2) in eight normal subjects in the basal state and after treatment with L-T3 (T3) and sodium ipodate for 2 weeks. T3 treatment resulted in a rise of serum TT3 from a baseline of 137 +/- 16 (+/- SE) to a peak of 239 +/- 15 ng/dl. Serum TT4 declined from 8.14 +/- 0.56 to 6.08 +/- 0.43 micrograms/dl, FT4 from 1.59 +/- 0.13 to 1.03 +/- 0.05 ng/dl, and TSH from 1.74 +/- 0.24 to 0.56 +/- 0.16 microU/ml. Basal VO2 increased from 2.66 +/- 0.11 to 3.15 +/- 0.09 ml/kg X min. Ipodate, on the other hand, led to a lower serum TT3 concentration (102 +/- 21 ng/dl), higher serum TT4 and FT4 (9.59 +/- 0.5 micrograms/dl and 1.91 +/- 0.13 ng/dl, respectively), and elevated TSH (3.64 +/- 0.14 microU/ml). Basal VO2 was reduced to 2.44 +/- 0.06 ml/kg X min. Linear regression analysis revealed an excellent positive correlation between serum TT3 and basal VO2 (n = 25; r = 0.747; P less than 0.001) and a significant negative correlation between serum TT3 and TSH (n = 26; r = -0.526; P less than 0.01). Serum TT4 and FT4 correlated negatively with VO2 and positively with serum TSH. The higher T4 level during ipodate treatment was associated with lower VO2 and higher TSH, and vice versa when T4 was suppressed while receiving T3. When ipodate was given concomitantly with T3 to five subjects, only the effects of T3, characterized by increased VO2 and decreased TSH, were evident. These data indicate that both basal VO2 and serum TSH are sensitive indices of thyroid hormone activities. The latter gives only the directional change (hyper- or hypothyroidism), while the former more accurately quantitates the magnitude of the derangement. Moreover, it appears that in man, T3, and not T4, is the primary hormone that regulates thermogenesis and TSH secretion.     

Free thyroxine values in dried blood spots on filter paper in newborns are related to both gestational age and birth body weight

The results of free thyroxine (FT4) measurements in dried blood spots on filter paper in 744 euthyroid newborns (616 at term, 128 preterm), 10 newborns with congenital hypothyroidism and 4 euthyroid newborns with congenital TBG deficiency are reported. FT4 was measured by column adsorption chromatography of free hormone followed by radioimmunoassay in the eluate. FT4 values averaged 24 +/- 0.2 pmol/L (mean +/- SE) in euthyroid newborns, 23.0 +/- 0.9 pmol/L in euthyroid newborns with TBG deficiency (p = NS), and 5.7 +/- 0.4 pmol/L in hypothyroid newborns (p less than 0.001 vs both groups). Total T4 (TT4) values in newborns with TBG deficiency were not different from those in hypothyroid newborns, but were significantly lower than those in euthyroid newborns without TBG abnormalities. FT4 values were higher in full-term newborns than in preterm newborns (25.2 +/- 0.3 vs 21.2 +/- 0.5 pmol/L, p less than 0.001). In both full-term and preterm newborns FT4 values in dried blood spots increased with birth body weight (bbw), virtually plateauing when bbw was greater than 2,500 g. The cut-off values established on the basis of the bbw (8.0 and 13.1 pmol/L for a bbw of less than or equal to 2,500 g and greater than 2,500 g, respectively) showed higher specificity and predictive value of positive results than the cut-off values based on the gestational age. In any case, the sensitivity, specificity and predictive values of FT4 determinations proved to be higher than those of TT4 and TSH measurements.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum free thyroid hormones in subclinical hypothyroidism

Serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations were measured in a group of 52 patients with subclinical hypothyroidism (SH) and in an equal group of age and sex-matched normal controls. SH was defined by normal total T4 (TT4) and total T3 (TT3) concentrations, normal FT4 and FT3 indices, raised TSH levels, in the absence of signs and symptoms of hypothyroidism. Serum FT4 levels averaged 6.1 +/- 1.6 pg/ml (mean +/- SD, p less than 0.001 vs controls), with values below lower normal limits in 33/52 patients; mean FT3 concentrations averaged 3.1 +/- 0.7 pg/ml (p less than 0.001 vs controls), with values below lower normal limits in 8/52 patients. The analysis of results by the Galen and Gambino predictive value model demonstrated a higher sensitivity, but a lower specificity of FT4 as compared to FT3 in the diagnosis of SH. These results indicate that FT4 should be measured in addition to TSH for the diagnosis of impending thyroid failure, thus showing that in many cases patients with so-called subclinical hypothyroidism are actually already mild hypothyroid.     

Intestinal Dysmotility Syndromes in the Elderly: Measurement of Orocecal Transit Time

Altered bowel habits are common symptoms in the elderly, yet the pathophysiology of age-related gastrointestinal dysmotility syndromes is poorly understood. The present study was designed to correlate changes in orocecal transit time (TT) in healthy elderly subjects with or without gastrointestinal dysmotility complaints. Twenty-two geriatric facility resident volunteers, mean age 82 yr (range 65-94 yr) participated, of whom 16 had gastrointestinal dysmotility symptoms. Orocecal TT in the elderly subjects did not differ from that in younger adult controls (100 +/- 11 min vs 93 +/- 20 min). However, orocecal TT was longer in geriatric females (112 +/- 14 min) than in males (70 +/- 6 min, p less than 0.01). We conclude that age alone does not prolong orocecal TT, except when dysmotility symptoms have been present for a prolonged period.     

Subclinical hypothyroidism may be associated with elevated high-sensitive c-reactive protein (low grade inflammation) and fasting hyperinsulinemia

The association between coronary heart disease and subclinical hypothyroidism (SCH) is unclear. We aimed to determine hs-CRP concentrations in patients with SCH. Seventy-seven patients (age 34.6 +/- 13.7 yr) with SCH (TSH > 4.2 microIU/ml and serum free thyroxine level between 0.932-1.71 ng/dL), and 80 control subjects (age 33.9 +/- 13.3 yr) were studied. Thyroid hormones, C-reactive protein, insulin, glucose, total, HDL, LDL and VLDL-cholesterol levels and HOMA-IR index were also determined. TSH levels of SCH group were higher than control (7.4 +/- 2.9 and 1.55 +/- 0.78 microIU/ml, respectively, p = 0.0001). However, FT4 levels were lower than control subjects (1.18 +/- 0.22 ng/dL and 1.38 +/- 0.26, respectively, p = 0.001). Serum hs-CRP levels of subjects with SCH were higher than control subjects (4.2 +/- 0.8 mg/l and 1.05 +/- 0.3 mg/l respectively, p = 0.0001). Insulin levels of SCH group were higher than control (8.5 +/- 4.3 microU/ml and 7.1 +/- 3.1 microU/ml respectively, p<0.02) but, Homa-IR levels of the two groups were not different. Mean total and LDL-cholesterol levels of SCH group were higher than control (p = 0.01 and p<0.02). We also found a positive correlation between hs-CRP levels and insulin (r = 0.362, p = 0.002 in men, r = 0.358, p = 0.0001 in women), TSH (r = 0.611, p = 0.0001 in men, r = 0.411 p = 0.0001 in women), and prolactin (r = 0.340, p = 0.01 in men r = 0.553, p = 0.0001 in women). Conclusions: Patients with SCH, irrespective of gender, have higher serum hs-CRP, insulin, total and LDL-cholesterol levels than healthy subjects. 2- High hs-CRP level, and thereby low grade inflammation may be associated with fasting hyperinsulinemia before insulin resistance becomes evident in patients with SCH.     

高血压脑出血甲状腺功能异常患者再出血及预后的观察

目的 探讨高血压脑出血(HICH)甲状腺功能异常患者再出血的发生与预后情况.方法 纳入盐城市亭湖区人民医院2014年5月至2019年5月收治的HICH甲状腺功能异常患者80例.根据患者是否发生再出血,分成再出血组14例、未再出血组66例.比较两组甲状腺功能指标,包括促甲状腺激素(TSH)、总甲状腺素(TT4)、总三碘甲...     

SERUM IODOTHYRONINE CONCENTRATIONS DURING INTRODUCTION OF THYROXINE REPLACEMENT THERAPY IN HYPOTHYROIDISM

Serum concentrations of total and free T4 (TT4 and FT4), total and free T3 (TT3 and FT3), rT3, T4 binding globulin (TBG), T3 uptake (T3U) and TSH were measured in 12 patients with severe hypothyroidism before and during the introduction of replacement therapy with oral T4. The dose of T4 was increased by increments of 50 micrograms at intervals of 4 weeks to a total of 200 micrograms daily. There was a linear correlation between the concentrations of FT3 and FT4 (FT3 = 1.35 + 0.23FT4, r = 0.916, P less than 0.001). The correlation between TT3 and TT4 was more complex: the data were best fitted by the expression TT3 = 0.195 square root TT4, (r = 0.936, P less than 0.001). The relatively greater rise in TT3 initially may reflect a greater binding of T3 by TBG when the concentration of T4 is low. TBG concentration fell after 50 and 100 micrograms of T4 but did not change at the higher doses. There was a simple linear relation between TT4 and rT3 (rT3 = -0.022 + 0.0027TT4, r = 0.921, P less than 0.001). The expected inverse relation between TSH concentration and the thyroid hormones was seen, the three closest correlations being between the logarithm of the TSH concentration and FT3, the ratio T4/TBG and FT4 (r = 0.927, -0.917 and -0.900 respectively). These correlations were significantly better (P less than 0.05) than the correlations with untransformed TSH values. Suppression of TSH occurred while FT3 tended to remain within normal limits, but FT4 was often raised.(ABSTRACT TRUNCATED AT 250 WORDS)     

Atrial natriuretic peptide in chronic heart failure in the rat: a correlation with ventricular dysfunction

To assess the relation between atrial natriuretic peptide and ventricular dysfunction, we simultaneously measured both atrial and plasma immunoreactive atrial natriuretic peptide concentrations in rats 4 weeks after myocardial infarction induced by left coronary artery ligation. When compared to controls (n = 39), rats with infarction (n = 16) had markedly elevated plasma immunoreactive atrial natriuretic peptide concentrations (1205.8 +/- 180.9 vs. 126.7 +/- 8.9 pg/ml, p less than 0.001) and reduced immunoreactive atrial natriuretic peptide concentrations in right and left atria (31.4 +/- 4.6 vs. 61.2 +/- 3.2 ng/mg, p less than 0.001; 14.9 +/- 2.2 vs. 32.7 +/- 2.4 ng/mg, p less than 0.001, respectively). Right ventricular weight increased in proportion to infarct size, and both were correlated with plasma immunoreactive atrial natriuretic peptide levels (r = 0.825, p less than 0.001 and r = 0.816, p less than 0.001, respectively). Right atrial immunoreactive atrial natriuretic peptide content was significantly higher than left in both controls and rats with infarction. Both right and left atrial immunoreactive atrial natriuretic peptide concentrations were negatively correlated with both right ventricular weight as well as plasma immunoreactive atrial natriuretic peptide concentrations (right atrium: r = -0.816, p less than 0.001, r = -0.708, p less than 0.01; left atrium: r = -0.687, p less than 0.01, r = -0.644, p less than 0.01, respectively). These results suggest that chronic stimulation of atrial natriuretic peptide release from both atria is associated with increased turnover and depleted stores of atrial natriuretic peptide in atria in proportion to the severity of heart failure. It also suggests that plasma atrial natriuretic peptide levels may be used as a reliable index of cardiac decompensation in chronic heart failure.     

Thyroid function in hyperemesis gravidarum

Plasma total T4 (TT4), T3 (TT3), free T4 (FT4), free T3 (FT3), thyroxine binding globulin, hCG, and erythrocyte zinc content were measured in 43 women with uncomplicated pregnancy and in 71 patients admitted with hyperemesis gravidarum. Plasma concentration of thyroid hormones in hyperemesis subjects showed wide variability and 32% of subjects had high TT4 (higher than mean +2 SD of normal pregnant subjects), 33% had high FT4, 20% had high TT3, and 20% had high FT3. Red cell zinc content, a tissue marker of thyroid status, in the hyperthyroxinemic subjects was not different from that of normothyroxinemic hyperemesis subjects or of subjects with uncomplicated pregnancy. The elevated TT4 concentration decreased spontaneously in all but two of the hyperemesis subjects to normal pregnant levels. The plasma FT4 concentration at presentation correlated with plasma hCG in hyperemesis gravidarum (partial correlation coefficient r = 0.411, P less than 0.01), but not in normal pregnancy (partial correlation coefficient r = 0.043) after allowing for the effect of gestational age. We conclude that approximately one third of hyperemesis subjects show transient hyperthyroxinemia and suggest that hCG or a molecular variant of hCG may stimulate the thyroid gland.     

Growth hormone replacement improves thyroxine biological effects: implications for management of central hypothyroidism

CONTEXT: The biological significance of GH-induced changes in serum TH concentrations is unknown. It has been suggested that serum free T(4) (FT(4)) should be targeted at the high-normal range during GH replacement. OBJECTIVE: Our objective was to evaluate the effects of GH replacement on T(4) biological effects. HYPOTHESIS: If GH modulates thyroxine biological effects, serum FT(4) should be targeted accordingly. DESIGN AND SETTING: We conducted observational (study 1) and interventional (studies 2 and 3)/outpatient studies. PATIENTS: Thirty-two GH-deficient patients (13 off GH; 22 on l-T(4)) participated in the study. INTERVENTIONS: In study 2, levothyroxine was administered to increase FT(4) (>1.0 ng/dl). In study 3, GH was administered or withdrawn. MAIN OUTCOME MEASURES: We measured FT(4), total T(3) (TT(3)), myocardial isovolumic contraction time (ICT), and resting energy expenditure (REE). RESULTS: In study 1, off-GH and on-GH groups had similar FT(4), but off GH showed lower TT(3) (P < 0.01) and REE (P = 0.02), higher ICT (P < 0.05) than on-GH and controls. On GH, ICT and REE correlated only with TT(3) (r = -0.48; r = 0.58; P < 0.05). Off GH, ICT correlated only with FT(4) (P < 0.01). In study 2, off GH, levothyroxine intervention increased FT(4) (P = 0.005) and TT(3) (P = 0.012), decreased ICT (P = 0.006), and increased REE (P = 0.013); ICT and FT(4) changes correlated (r = -0.72; P = 0.06). On GH, levothyroxine increased FT(4) (P = 0.0002), TT(3) (P = 0.014), and REE (P = 0.10) and decreased ICT (P = 0.049); REE and TT(3) changes correlated (r = 0.60; P = 0.05). In study 3, GH decreased FT(4), increased TT(3), decreased ICT, and increased REE (P < 0.05). REE correlated (P < 0.05) with IGF-I (r = 0.57) and TT(3) (r = 0.64). ICT correlated only with TT(3) (r = -0.46). CONCLUSIONS: GH replacement improves the biological effects of T(4). Serum FT(4) should be targeted at the high-normal range in GH-deficient patients only off GH replacement.