Euthyroid Control Subjects Research Articles

Association of High Serum Leptin Level with Papillary Thyroid Carcinoma: A Case-Control Study.

Background: Recently, the prevalence of thyroid cancer has increased. Although there are known risk factors for thyroid cancer, none of them can justify this recent increase. In addition to the known risk factors, other risk factors have been proposed. Leptin can be considered as one of these risk factors due to the recent increase in the prevalence of obesity in the population. Leptin is a common factor in obesity and thyroid cancer. Leptin exerts anti-apoptotic and mitogenic effects on cancer cells and also acts as an angiogenic factor. This study aimed to evaluate the serum leptin level in individuals who suffer from papillary thyroid carcinoma (PTC), cases with benign thyroid nodules (BTN), and a healthy group. Materials and Methods: In this study, newly diagnosed patients with PTC, BTNs, as well as euthyroid healthy control subjects without nodules were included. In all these participants, various clinical and laboratory parameters including thyroid function tests and serum leptin levels were measured and compared between the three study groups. For patients with PTC, leptin was assessed 12 weeks after total thyroidectomy. Results: Ninety-one cases with PTC, 90 cases with BTNs, and 88 controls were recruited. Serum leptin levels in the PTC group, benign group, and the control group were 22.34, 17.60, and 13.83 ng/ml, respectively, which was considerably higher in PTC cases compared to those with benign nodules and control group (P<0.001). There was a significant association between leptin with BMI, tumor size, and tumor stage in PTC patients. Also, in patients with BTNs, a correlation between BMI, tumor size, and leptin was observed. Conclusion: Serum leptin levels were considerably higher in cases with PTC than those with BTNs and controls and can be considered as a potential tumor marker for papillary thyroid cancer.

Mean Platelet Volume in Patients With Subclinical Hypothyroidism Attending at A Tertiary Care Hospital of Bangladesh

Background: Subclinical hypothyroidism (SCH) is a common endocrine disorder affecting about 3-8% of the general population. On the other hand, mean platelet volume (MPV) is an indicator of platelet activity, and elevated MPV is associated with adverse cardio-metabolic complications. This study was conducted to observe MPV in SCH and to correlate it with thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels. Materials and Methods: This cross-sectional observational study was conducted in Medicine and Endocrinology OPD of US- Bangla Medical College &amp; Hospital over twelve (12) months from September 2020 to August 2021. This study included forty (40) cases of newly detected SCH and twenty (20) age &amp; body mass index (BMI) matched euthyroid control subjects as per inclusion and exclusion criteria. Results: SCH group had higher TSH and MPV than controls (P value &lt;0.001 and &lt;0.05 respectively) where age, BMI, and FT4 level were comparable (P value&gt;0.05). MPV shows a positive correlation with BMI in SCH &amp; controls (P values &lt;0.05). MPV shows a significant positive correlation with TSH and a negative correlation with FT4 only in SCH (P&lt;0.05) but not in controls (P value&gt;0.05). Conclusion: Patients with SCH have elevated MPV, so they are at increased risk of developing an adverse cardiovascular outcome. J Dhaka Med Coll. 2022; 31(1) : 61-65

Static and dynamic pupillary features in graves’ ophthalmopathy

ABSTRACT Clinical Relevance Pupillary characteristics may be affected in patients with Graves’ ophthalmopathy (GO). However, small changes cannot be observed with clinical examination. Ophthalmologists and optometrists should be aware that dynamic pupillometry may have an important place in the quantitative assessment of pupillary characteristics in this patient population. Background The aim of this study was to compare the static and dynamic pupillary responses of hyperthyroid and euthyroid GO patients and healthy control subjects. Methods The study enrolled 20 hyperthyroid patients with GO (Group 1), 20 euthyroid patients with GO (Group 2) and 40 control subjects with normal thyroid function tests and no known illness (Group 3). Following detailed ophthalmological examination, static and dynamic pupillometry measurements were performed. Dynamic pupillometry measurements including resting diameter, amplitude of pupil contraction, latency of pupil contraction, duration of pupil contraction, latency of pupil dilation, duration of pupil dilation, and velocity of pupil dilation were undertaken. Static pupillometry measurements including scotopic, mesopic, low-photopic, and high-photopic pupil diameters (PD) were undertaken. Data from the right eyes of the participants were used for statistical analysis. Results Regarding the dynamic pupillary measurements, the latency of pupil contraction value was significantly higher (p = 0.007), and the velocity of pupil dilatation was significantly lower (p = 0.004) in Groups 1 and 2 compared to the Group 3. In static pupillary measurements, there were statistically significant differences between the GO group (Group 1 and 2) and Group 3 with regard to scotopic (p = 0.002), mesopic (p = 0.002), and low-photopic PD (p = 0.001). Conclusion Scotopic, mesopic and low photopic PD, latency of pupil contraction and velocity of pupil dilatation values were significantly different in both hyperthyroid and euthyroid GO patients when compared to healthy control subjects.

Epigenetics effect on pathogenesis of thyroid-associated ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO) is an autoimmune disease. Recent studies have found the aberrant epigenetics in TAO, including DNA methylation, non-coding RNAs, and histone modification. Many genes have an aberrant level of methylation in TAO. For example, higher levels are found in CD14, MBP, ANGLE1, LYAR and lower levels in DRD4 and BOLL. Non-coding RNAs are involved in the immune response (miR-146a, miR-155, miR-96, miR-183), fibrosis regulation (miR-146a, miR-21, miR-29), adipogenesis (miR-27) and are thought to play roles in TAO. MicroRNA is also related to the clinical activity score (miR-Let7d-5p) and may be a predictor of glucocorticoid therapy (miR-224-5p). The quantities of H4 in TAO are increased compared with euthyroid control subjects, and the role of histone modifications in Graves' disease may lead to better understanding of its role in TAO. More studies are needed to explain the role of epigenetics in TAO and provide potential therapeutic strategies.

Prevalence and Risk Factors of Left Ventricular Diastolic Dysfunction in Patients With Hyperthyroidism.

BackgroundLeft ventricular (LV) diastolic dysfunction has been demonstrated to be an independent predictor of the future heart failure. Heart failure is one of the severe complications caused by overt hyperthyroidism. However, the effects of overt hyperthyroidism on diastolic dysfunction are conflicting, and little is known about the prevalence and risk factors of the diastolic dysfunction in patients with overt hyperthyroidism.MethodsA total of 388 patients with overt hyperthyroidism were included and compared with 388 age- and gender- matched euthyroid control subjects. LV diastolic function was evaluated by traditional and tissue-Doppler echocardiography. Routine clinical medical data and echocardiographic parameters were recorded for analysis.ResultsThe prevalence of LV diastolic dysfunction was 35.1% among hyperthyroid patients and significantly higher than control subjects whose prevalence was 25.5% (P = 0.003), and it increased with age and body mass index (BMI) in patients with overt hyperthyroidism. The possible risk factors for LV diastolic dysfunction, such as hypertension, diabetes, decreased estimated glomerular filtration rate (eGFR), and increased level of thyroid hormones weren’t associated with LV diastolic dysfunction. However, overweight or obese were significantly associated with LV diastolic dysfunction (OR = 3.024, 95% CI = 1.517–6.027, P = 0.002) compared with normal BMI. When compared with age <40 years old group, 40-50 years old group, 50-60 years old group and age ≥60 years old group were significantly associated with LV diastolic dysfunction, with ORs of 2.976 (95% CI = 1.744–5.019), 12.424 (95% CI = 4.934–31.283), 24.966 (95% CI = 5.975–104.321), respectively.ConclusionLV diastolic dysfunction was very common, in particular, in older and overweight or obese patients with overt hyperthyroidism. Additionally, age and BMI were independent risk factors for LV diastolic dysfunction, while the level of thyroid hormones was not. Therefore, besides the LV systolic function, we also need focus on the diastolic function in patients with overt hyperthyroidism in clinical work, especially the older and overweight or obese patients.

Role of reduced thyroid hormone status on bone mineral metabolism

Background: The most common endocrine disorder is hypothyroidism which accounts to 11%. Thyroid hormones have a wide array of functions such as physiological growth and development of skeletal system, maintenance of basal metabolic rate and regulation of various metabolisms, including mineral metabolism. Nowadays due to its direct action on bone turn over, thyroid hormones are considered to have an important role on bone mineral metabolism. Thyroid disorders are important cause for secondary osteoporosis. So the present study was done to know the levels of bone minerals, calcium and phosphorus in hypothyroidism and its relation with thyroid hormone levels. Methods: A case-control study was conducted on 30 hypothyroid patients and 30 euthyroid healthy controls in the age group of 20-60 years. Blood samples were collected from all the study population. Serum total triiodothyronine, total thyroxine and TSH by Enzyme-Linked Immunosorbent Assay, Serum calcium by Arsenazo III method, phosphorous by ammonium molybdate method were estimated. Results: Serum calcium levels in cases was found to significantly reduced when compared to controls (p&lt;0.001). Serum phosphorous levels also showed considerable elevation in cases when compared to controls (p&lt;0.001). There was a significant negative correlation between TSH and serum calcium in cases. Conclusion: The present study indicated the important role of reduced thyroid hormone status on bone mineral metabolism. This study concludes that serum calcium was significantly reduced and phosphorus levels were significantly increased in hypothyroid patients when compared to euthyroid control subjects. So frequent monitoring of serum calcium and phosphorus in hypothyroid patients would reduce the burden of bone pathologies.

Altered attention networks in patients with thyroid dysfunction: A neuropsychological study

Patients with thyroid dysfunction (31 hypothyroid, 32 subclinical hypothyroidism, 34 hyperthyroid, and 30 subclinical hyperthyroidism) and 37 euthyroid control subjects were recruited and performed the attention network test (ANT), which can simultaneously examine the alertness, orientation and execution control of the participants. Patients with hypothyroidism had abnormalities in the alerting network, and those with hyperthyroidism had impairments of the alerting and executive control networks. No attention networks deficit existed in patients with subclinical hyperthyroidism and subclinical hypothyroidism. The anxiety and depression scores of patients with thyroid dysfunction were significantly higher than those of the healthy control group. Covariance analysis demonstrated that interactions between group and Hamilton Anxiety Scale scores, group and HAMD score were not significant, but there was a significant main effect for group when analyzing the difference in values of the alerting network between groups. Further, the efficiency of the executive control network was negatively correlated with the T4 level in the hypothyroidism group, and positively correlated with the T4 level in the hyperthyroidism group. T4 or T3 level and efficiencies of the executive control network had a significant quadratic U-shaped relationship in all participants. In summary, the patients with four kinds of thyroid dysfunction exhibited different characteristics of ANT performance. Patients with thyroid dysfunction had various degrees of anxiety and depression disorders, but anxiety and depression disorders had no effect on the differences in the executive control network between the groups.

The association of circulating sclerostin level with markers of bone metabolism in patients with thyroid dysfunction.

The aim of this study was to compare serum sclerostin concentrations in patients with thyroid dysfunction with euthyroid control subjects and to assess the relationship between sclerostin and markers of bone metabolism (osteocalcin and beta-cross-laps). The study included 30 patients with thyroid dysfunction (hypothyroidism, hyperthyroidism and subclinical hyperthyroidism) and ten euthyroid controls. Free thyroxine (FT4) was measured by radioimmunoassay, while thyroid stimulating hormone (TSH) concentration was determined immunoradiometrically. We used an ELISA kit to determine the sclerostin level. The electrochemiluminescence method was applied for measuring the bone markers. Sclerostin levels were significantly lower in hypothyroid patients (p=0.009) and significantly elevated in hyperthyroid patients (p=0.008) compared to control values. Hyperthyroid patients also had higher sclerostin than patients with subclinical hyperthyroidism (p=0.013). Sclerostin concentrations were negatively correlated with TSH levels (r=-0.746, p<0.001), but positively with FT4 (r=0.696, p < 0.001). Moreover, sclerostin was positively associated with osteocalcin (r=0.605, p=0.005) and beta-cross-laps levels (r=0.573, p=0.008) in all thyroid patients. Serum sclerostin is significantly affected in subjects with thyroid dysfunction. Both sclerostin and thyroid status affect bone homeostasis, which is reflected through the significant correlations with osteocalcin and beta-cross-laps.

Stimulatory TSH-Receptor Antibodies and Oxidative Stress in Graves Disease.

We hypothesized that TSH-receptor (TSHR) stimulating antibodies (TSAbs) are involved in oxidative stress mechanisms in patients with Graves disease (GD). Nicotinamide adenine dinucleotide phosphate oxidase, isoform 2 (NOX2); oxidative parameters; and oxidative burst were measured in serum, urine, and whole blood from patients with GD and control subjects. Superoxide production was investigated in human embryonic kidney (HEK)-293 cells stably overexpressing the TSHR. Lipid peroxidation was determined by immunodot-blot analysis for protein-bound 4-hydroxy-2-nonenal (4-HNE) in human primary thyrocytes and HEK-293-TSHR cells. Serum NOX2 levels were markedly higher in hyperthyroid untreated vs euthyroid treated patients with GD, hyperthyroid patients with toxic nodular goiter, and euthyroid healthy control subjects (all P < 0.0001). Urine oxidative parameters were increased in patients with GD vs patients with toxic goiter (P < 0.01) and/or control subjects (P < 0.001). The maximum of the zymosan A- and phorbol 12,13-dibutyrate-induced respiratory burst of leukocytes was 1.5-fold higher in whole blood from hyperthyroid patients with GD compared with control subjects (P < 0.001 and P < 0.05). Monoclonal M22 TSAbs stimulated cAMP (HEK cells) in a dose-dependent manner. M22 (P = 0.0082), bovine TSH (P = 0.0028), and sera of hyperthyroid patients with GD (P < 0.05) increased superoxide-specific 2-hydroxyethidium levels in HEK-293 TSHR cells after 48-hour incubation vs control subjects. In contrast, triiodothyronine (T3) did not affect reactive oxygen species (ROS) production. In primary thyrocytes, the 4-HNE marker was higher in patients with GD vs control subjects at 6 and 48 hours (P = 0.02 and P = 0.04, respectively). Further, after 48-hour incubation of HEK-293 TSHR cells with patient sera, 4-HNE was higher in patients with untreated GD compared with control subjects (P < 0.05). Monoclonal M22 and polyclonal serum TSAbs augment ROS generation and/or induce lipid peroxidation.

Cognitive functioning and quality of life in patients with Hashimoto thyroiditis on long-term levothyroxine replacement.

Intrinsic imperfections of thyroid hormone replacement therapy may affect long-term general well-being. In patients with Hashimoto thyroiditis (HT), cognitive functioning may be affected via altered thyroid hormones action as well as by the autoimmune process. The aim of this study was to evaluate cognitive function and quality of life (QoL) in patients on long-term levothyroxine replacement for HT in relation to thyroid function tests and TPO (thyroid-peroxidase) antibody (TPOAb) status. Retrospective cross-sectional study. One-hundred-and thirty patients with HT on long-term levothyroxine replacement and 111 euthyroid control subjects. Both groups were divided into two age subgroups, 20-49 years (N = 59 vs N = 79) and > 50 years (N = 71 vs N = 32). Evaluation included biochemical and neuropsychological tests, evaluating attention, global cognitive status, verbal and working memory, executive function, depression and anxiety, and quality of life. We used ANOVA and partial correlations to test for significant associations. FT4 (free-thyroxine), FT3 (free-triiodothyronine) levels and FT3/FT4 ratio were not different between patients and controls. Mean TSH (thyroid-stimulating hormone) was normal in all subjects but significantly higher in the patients (20-49 yrs:3.64 ± 2.74 vs 1.93 ± 1.10, >50 yrs:3.93 ± 2.84 vs 1.91 ± 0.90). Antibodies (TgAb,TPOAb) were higher in patients. Global cognitive function (MMSE-Mini mental state examination), conceptual tracking (TMT-Trail Making Test:A/B), verbal divergent thinking (like Phonemic fluency test), and anxiety and depression scores were significantly worse in patients vs controls. QoL was impaired in patients. there was a significant negative correlation between antibodies (TPOAb, TgAb) and quality in life (total SF36 score). Patients on long-term levothyroxine replacement show persistent impairments in both cognitive functioning and general well-being.

Is thyroid autoimmunity itself associated with psychological well-being in euthyroid Hashimoto's thyroiditis?

Recent studies imply that euthyroid Hashimoto's thyroiditis (HT) might be related with impaired HRQoL, depression and anxiety. Ninety three patients with euthyroid HT and 31 age- and gender-matched euthyroid control subjects were enrolled into this study. SF-36 questionnaire, Beck Depression Inventory and Beck Anxiety Inventory tests were used for evaluating HRQoL, depression and anxiety. Beck Depression Inventory scores were higher in patients with HT compared to control subjects (7.5 (4.0-14.75) vs. 5.0 (2.25-9.0), p=0.008). Beck Anxiety Questionnaire scores were also higher in patients with HT than controls (9.50 (5.0-17.0) vs. 5.0 (2.0-11.75), p=0.021). In SF-36 questionnaire; physical functioning (26.0 (20.0-28.0) vs. 29.0 (26.0-30.0), p=0.038), general health (16.4 (13.4-20.4) vs. 19.4 (16.3-21.2), p=0.026) and mental health (20.5 (16.0-23.0) vs. 23.0 (21.0-25.0), p=0.001) scores were lower in patients with HT than control subjects. There were no significant differences between patients with HT under levothyroxine replacement therapy compared to those without therapy in terms of depression and anxiety scores and components of SF-36 questionnaire. Beck Depression Inventory scores were positively correlated with TSH (r=0.250, p=0.01). In SF-36, role physical (r=0.192, p<0.05) and vitality (r=0.181, p<0.05) were positively correlated with fT4. Role emotional was negatively correlated with TSH (r=-0.185, p<0.05) and anti-TPO (r=-0.234, p<0.05). Mental health was negatively correlated with anti-TPO (r=-0.287, p<0.01). HRQoL is impaired and depression and anxiety scores are high in patients with euthyroid HT independent of levothyroxine replacement. Therefore, our results indicate that thyroid autoimmunity itself may have an impact on psychological well-being in euthyroid patients with HT.

Thickening of the epicardial adipose tissue can be alleviated by thyroid hormone replacement therapy in patients with subclinical hypothyroidism.

Subclinical hypothyroidism (SCH) is a common disorder which has adverse cardiovascular effects. Epicardial adipose tissue (EAT), a novel marker of cardiovascular risk, is increased in SCH. We aimed to investigate whether L-thyroxine treatment can reverse the thickening of EAT in SCH. Forty-four patients with SCH and 42 euthyroid control subjects were included. EAT thickness was measured using transthoracic echocardiography at baseline and after restoration of the euthyroid status with 3 months of L-thyroxine treatment. At baseline, mean EAT thickness was significantly greater in the SCH group when compared to the control group (6.3 ± 1.7 mm vs. 4.1 ± 0.9 mm, respectively, p < 0.001). There was a significant positive correlation between baseline serum thyroid stimulating hormone (TSH) level and EAT thickness in the SCH group. There was a significant reduction in mean EAT thickness in response to L-thyroxine treatment (6.3 ± 1.7 mm vs. 5.1 ± 1.4 mm, p < 0.001). The decrease in EAT thickness after L-thyroxine treatment when compared to baseline (DEAT) significantly correlated to the difference in TSH levels before and after treatment (DTSH; r = 0.323; p = 0.032). Epicardial adipose tissue thickness is increased in patients with SCH. This thickening was alleviated with restoration of the euthyroid status with L-thyroxine treatment in our study population of predominantly male, relatively old subjects with greater baseline EAT thickness.

Subclinical Hypothyroidism in PCOS: Impact on Presentation, Insulin Resistance, and Cardiovascular Risk.

Aim of Study. To assess status of thyroid function and thyroid disorders particularly subclinical hypothyroidism (SCH) in subjects with polycystic ovarian syndrome (PCOS) and impact of SCH on various clinical and biochemical parameters and cardiovascular risk in PCOS. Methods. Hundred females diagnosed with PCOS as per Rotterdam criteria and 100 normal controls were recruited and were subjected to elaborate anthropometric, clinical, and biochemical assessment. Results. Notable findings included significantly higher frequency of subjects with subclinical hypothyroidism (p = 0.0002), autoimmune thyroiditis (p < 0.001), and goitre (p = 0.02) in polycystic ovarian syndrome subjects compared to control subjects. Further SCH PCOS subjects were found to harbor significantly higher HOMA-IR (p < 0.05) and frequency of subjects with dyslipidemia (p < 0.05) compared to both euthyroid PCOS and euthyroid control subjects. Though frequency of subjects with cardiovascular risk factors was higher in SCH PCOS group than euthyroid PCOS group, it failed to reach statistical significance. Conclusion. We concluded that PCOS is associated with high incidence of SCH and AIT compared to normal population and SCH poses increased risk of cardiovascular disorder in PCOS.

Insulin Resistance in Patients with Benign Thyroid Nodules.

Recently, it has been questioned whether insulin resistance is associated with thyroid nodules. The aim of this study was to examine insulin resistance prevalence in a case-control study of patients with benign thyroid nodules in an iodine-sufficient area. This was a single-center, case-control study on euthyroid patients with benign nodular diseases. Thirty newly diagnosed patients with benign thyroid nodules according to fine needle aspiration cytology were investigated for insulin resistance. As a control group, 30 euthyroid control subjects with normal thyroid sonography without nodule were recruited from the general population. The participants were matched in pairs by age, gender, and body mass index. The diagnosis of insulin resistance was made when the homeostasis model assessment of insulin resistance (HOMA-IR) index was more than 2.5. The mean of HOMA-IR value was significantly higher in patients compared to controls (1.32 ± 0.65 vs. 0.76 ± 0.36, P-value < 0.001). Insulin resistance was seen in two subjects with thyroid nodules (6.7%), but none in the control group. There was a positive significant correlation between HOMA-IR and thyroid nodule size (r-value: +0.38, P < 0.03). Patients with thyroid nodules have higher HOMA-IR value. There is an association between insulin resistance and benign thyroid nodules. More investigations are required to define the role of this factor in thyroid nodule formation.

Biochemical role of serum fructosamine in patients with thyroid disorders

Background: Fructosamine (FA) is the product of a reaction between glucose (sugar) and albumin (protein). It is used to monitor the short-term glycemic changes in patients with diabetes and may have a role in conjugation with glycated hemoglobin. Aims & Objective: Fructosamine test is used to evaluate the average amount of glucose in blood over a period of 2–3 weeks. FA is a useful indicator to measure the peripheral metabolic function in patients with thyroid disorders. As serum thyroid function tests, fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), serum FA ratios occupied our attention, their inconsistency in the subjects with subclinical hypothyroidism, overt hypothyroidism, and hyperthyroidism in relation to the euthyroid healthy control subjects was studied here. Materials and Methods: This study was conducted on 100 patients with overt hypothyroidism, subclinical hypothyroidism, and hyperthyroidism attending the medical OPD and radioimmunoassay laboratory of the Department of Biochemistry, Jawaharlal Nehru Medical College and Hospital, Ajmer, Rajasthan, India. Results: The mean glycated hemoglobin level was higher in study group than in controls, and it was not statistically significant. The mean serum FA level was higher in patients with overt hypothyroidism and subclinical hyperthyroidism and lower in those with hyperthyroidism than that in controls. It was found to be highly statistically significant. Conclusion: The FA values, which are largely higher than FPG and HbA1c values, indicate a higher propensity to glycation and a decrease turnover of the proteins in the patients with overt hypothyroidism and subclinical hypothyroidism; contrary results were observed in individuals with hyperthyroidism.

Effect of treatment of overt hypothyroidism on insulin resistance

To investigate the impact of hypothyroidism and thyroxine therapy on insulin sensitivity in patients with overt hypothyroidism. The study included twenty seven overtly hypothyroid and fifteen healthy euthyroid South Western Asian females. Both groups had matching age and body mass index. Physiological and pathological conditions as well as medications that may alter thyroid function, glucose homeostasis or serum lipids were ruled out. Serum thyrotropin (TSH), free tetraiodothyronine (FT4), free triiodothyronine (FT3), fasting insulin (FI), fasting plasma glucose (FPG), total cholesterol and triglycerides were measured before and six months after initiating thyroxine therapy for hypothyroid patients and once for the control group. Insulin resistance (IR) was estimated using homeostasis model assessment (HOMA-IR) and Body mass index (BMI) was calculated. Both study groups, hypothyroid patients and euthyroid control subjects, had matching age and body mass index (P-value 0.444, 0.607 respectively). No significant difference was found between the hypothyroid patients and the euthyroid control group regarding fasting plasma glucose, fasting insulin, insulin resistance, total cholesterol and triglycerides (P-values 0.432, 0.621, 0.883, 0.586, 0.05 respectively). In the hypothyroid patients, triglycerides showed direct correlation to TSH and inverse correlation to FT3. Similarly total cholesterol inversely correlated to FT3 but its direct correlation to TSH did not reach statistical significance. After thyroxine replacement and reaching an euthyroid state as confirmed by clinical and laboratory data, there was no significant change in fasting plasma glucose, insulin resistance or triglyceride level (P-value 0.216, 0.204, 0.175 respectively) while total cholesterol significantly decreased (P-value 0.043) and fasting insulin significantly increased (P-value 0.047). Hypothyroidism has no impact on insulin sensitivity. Correction of hypothyroidism is not associated with a significant change of insulin sensitivity or triglycerides, but with a significant reduction of total cholesterol.

Different patterns of fibrinolytic abnormalities and lipid profile in hypothyroid and hyperthyroid patients

Altered fibrinolytic parameters and serum lipid profile are strongly related to thyroid dysfunction. To investigate the patterns of the fibrinolytic abnormalities and serum lipid profile in the hypo- and hyperthyroid patients. We also took an aim at studying the relationships between free T4 levels (FT4) and these parameters. Hyperthyroid (n = 30), hypothyroid (n = 20) patients and euthyroid control subjects (n = 30) were evaluated for several fibrinolytic parameters including plasma plasminogen activator inhibitor-1 (PAI-1) and D-dimer (D-D). Serum lipid profile and lipoprotein(a) (Lp(a)) were also measured. We found different patterns of fibrinolytic abnormalities and lipid profile in hypo- and hyperthyroid patients. The hypothyroid patients had low plasma PAI-1 levels and high D-D values as compared to hyperthyroid patients (p < 0.001) and euthyroid control subjects (p < 0.05 and 0.001, respectively). In sharp contrast, the hyperthyroid patients had high plasma PAI-1 levels (p < 0.001) but without concomitant change in plasma D-D values, as compared to the euthyroid control subjects. Hypothyroidism was associated with high total cholesterol, triglycerides, LDL-C and Lp(a) levels and low HDL-C levels as compared to both hyperthyroid and euthyroid states (p < 0.001). FT4 levels were correlated positively with HDL-C but negatively with total cholesterol, triglycerides, LDL-C and Lp(a) levels in both hypo- and hyperthyroid patients. Also FT4 levels were correlated positively with PAI-1 but negatively with D-D in both hypo- and hyperthyroid patients (p < 0.02, 0.01, 0.001 and 0.03 respectively). We found hyperfibrinolytic, and hypofibrinolytic patterns in hypothyroid, hyperthyroid patients, respectively. The hypothyroid patients had atherogenic lipid profile. These variations indicate possible pathophysiologic roles for thyroid hormones in the regulation of the fibrinolytic system and lipid profile. Mechanisms of these variations are open for future investigations.

Mean Peak Systolic Velocity of the Superior Thyroid Artery is Correlated with Radioactive Iodine Uptake in Untreated Thyrotoxicosis

To evaluate the correlation between mean superior thyroid artery peak systolic velocity (STA-PSV) and radioactive iodine uptake (RAIU) in Chinese patients with untreated thyrotoxicosis, using retrospectively and prospectively collected data. Patients with untreated thyrotoxicosis (n = 220) and euthyroid control subjects (n = 30) underwent thyroid function, thyroid autoantibody and thyroid ultrasonography tests. Mean STA-PSV was measured by ultrasonography. RAIU tests identified 168 patients with Graves' disease and 52 with destructive thyroiditis. Linear correlation of mean STA-PSV with 3-h and 24-h RAIU, and sensitivity, specificity and receiver operating characteristic (ROC) curves for mean STA-PSV in the differential diagnosis of Graves' disease and destructive thyroiditis were calculated. Mean STA-PSV was significantly higher in Graves' disease than in destructive thyroiditis. Mean STA-PSV correlated positively and significantly with 3-h and 24-h RAIU. Area under the ROC curve of mean STA-PSV for the differential diagnosis of Graves' disease and destructive thyroiditis was 0.825 (optimum cut-off value of mean STA-PSV, 45.25 cm/s; sensitivity, 80.4%; specificity, 81.4%). Detection of mean STA-PSV by ultrasonography agrees with RAIU and is useful for the differential diagnosis of thyrotoxicosis in Chinese patients.

Effects of Physical Activity on Body Composition and Fatigue Perception in Patients on Thyrotropin-Suppressive Therapy for Differentiated Thyroid Carcinoma

Subclinical thyrotoxicosis (scTox) may be associated with alterations in body composition and fatigue that can be possibly reversed with physical activity. The aim of the present study was to evaluate whether the systematic practice of physical activity improves lower extremity muscle mass and fatigue perception in patients with scTox. We studied 36 patients (2 men) with median age of 48.0 (43.0-51.0) years, body mass index of 27.4 (22.1-30.2) kg/m(2), thyrotropin <0.4 mU/L, and free thyroxine between 0.8 and 1.9 ng/dL and 48 control subjects (C group; 7 men). Patients were randomly divided in two groups according to the adherence to the exercise training: scTox-Tr (n = 19)-patients who adhered to the exercise intervention and scTox-Sed (n = 17)--patients who did not adhere to it. The C group did not participate in the randomization. The exercise training was supervised by a physical education instructor, and it was composed of 60 minutes of aerobic activity and stretching exercises, twice a week, during 12 weeks. In both groups, body composition was assessed (anthropometric method), and the Chalder Fatigue Scale was determined at baseline and after 3 months of intervention (scTox-Tr group) or observation (scTox-Sed group). At baseline, patients with scTox had lower muscle mass and mid-thigh girth and more fatigue on the Chalder Fatigue Scale than euthyroid control subjects. The scTox-Tr group had an increase in muscle mass, reduction in the variables reflecting whole body fat, and lesser perception of fatigue during the exercise training period (p ≤ 0.05 for these parameters at the start and end of the exercise training period). scTox is associated with lower muscle mass and mid-thigh girth and more fatigue. Physical activity training can partially ameliorate these characteristics. More studies are needed to determine what training program would be optimum, both in terms of beneficial effects and for avoiding potential adverse responses.

Effects of Thyroid Hormone on A1C and Glycated Albumin Levels in Nondiabetic Subjects With Overt Hypothyroidism

OBJECTIVEWe aimed to determine the effects of thyroid hormone on A1C and glycated albumin (GA) in nondiabetic patients with overt hypothyroidism.RESEARCH DESIGN AND METHODSA1C levels were measured in 45 nondiabetic patients with overt hypothyroidism and 180 euthyroid control subjects. A1C, GA, fasting blood glucose (FBG), 1,5-anhydroglucitol, and erythrocyte indexes were determined in 30 nondiabetic patients with overt hypothyroidism before and after thyroid hormone replacement.RESULTSA1C levels were higher in patients with hypothyroidism compared with control subjects. A1C levels were decreased by thyroid hormone replacement. Thyroid hormone replacement increased serum erythropoietin, reticulocyte count, and mean corpuscular hemoglobin (MCH). The change in A1C level was significantly correlated with the change in reticulocyte count or MCH. Thyroid hormone replacement decreased serum levels of albumin and GA. However, FBG and 1,5-anhydroglucitol levels were not altered.CONCLUSIONSLevels of A1C and GA are spuriously high in nondiabetic patients with overt hypothyroidism.