Overt Hypothyroidism Group Research Articles

The relationship between oxidative stress and autoimmunity in Hashimoto's thyroiditis.

We have aimed to study the relation between Hashimoto's thyroiditis (HT) and thyroid autoantibodies and oxidative stress parameters in euthyroid, subclinical and overt hypothyroid stages. A total of 124 patients were included in the study; 93 of whom were newly diagnosed with HT (31 patients in each of the euthyroid, subclinical hypothyroid and overt hypothyroid subgroups), aged over 18 and had not received any prior treatment and 31 of whom were healthy volunteers. Total oxidant status (TOS) and oxidative stress index (OSI) levels were higher, and total antioxidant status (TAS) and total thiol and arylesterase levels were lower in the overt hypothyroid group compared to other groups. TOS and OSI levels increased, and TAS levels decreased significantly in each phase from euthyroid, subclinical hypothyroid, to overt hypothyroid subgroups among HT patients. There was a negative correlation between TAS, log (paraoxonase1) and paraoxonase1/HDL and anti-thyroid peroxidase and a negative correlation between anti-thyroglobulin and total thiol. It was also determined that overt hypothroidism was an individual predictor that effects all of the oxidative stress parameters, but not total thiol, levels. Our results suggest that oxidative stress increases continuously during the development of subclinical hypothyroidism and overt hypothyroidism in patients with HT. To determine whether this is a cause or result, randomized, controlled trials that study the effect of antioxidant treatment on the development of overt hypothyroidism and its consequences, e.g., increase in total cholesterol levels, may be performed in euthyroid and/or subclinical hypothyroid patients with HT.

Mild hypothyroidism improves glucose tolerance in experimental type 2 diabetes

Background: Co-existence of type 2 diabetes and hypothyroidism is an emerging trend observed in clinical practice. Although the effects of isolated type 2 diabetes and hypothyroidism are well known, there are limited studies addressing the metabolic complications when these two conditions co-exist. The aim of the present study was to assess the interaction between type 2 diabetes and hypothyroidism with respect to glucose tolerance, dyslipidemia and redox balance in a state were these two diseases coexist. Methods: Sixty male Wistar Albino rats were randomised into six groups. Group 1: control, Group 2: overt hypothyroidism, Group 3: mild hypothyroidism, Group 4: type 2 diabetes, Group 5: mild hypothyroidism+type 2 diabetes, Group 6: overt hypothyroidism+type 2 diabetes. Experimental hypothyroidism was created by the administration of propyl-2-thiouracil and type 2 diabetes by feeding rats with 60% fructose (w/w). The duration of the study was 6weeks. All the parameters were estimated at the start (basal) and the end of the study. Intraperitoneal glucose tolerance test was carried out and area under curve (AUC) calculated to assess the glucose tolerance. Thyroid profile, lipid profile and oxidative stress parameters were also measured. Results: Plasma TSH level was elevated 3-fold in the mild hypothyroid group and 15.2-fold in the overt hypothyroid group in comparison to the control group. Thyroid profile was found to be normal in type 2 diabetic group. There was no significant difference between hypothyroidism and hypothyroidism+diabetes groups with respect to thyroid profile. Among the six groups the degree of glucose intolerance was found to be maximum for overt hypothyroidism+diabetes group, followed by diabetes group and overt hypothyroidism group. An interesting finding was that glucose intolerance was significantly reduced in mild hypothyroidism+diabetes group (increase in AUC: 48.04%) in comparison with isolated diabetes group (increase in AUC: 71.63%). Similar results were obtained with parameters of oxidative stress. Oxidative stress was observed in overt hypothyroidism+diabetes, diabetes, overt hypothyroidism groups with severity decreasing in that order. Coexistence of mild hypothyroidism with diabetes decreased oxidative stress in comparison with isolated diabetes group. There was no statistical difference in lipid profile between mild hypothyroidism+diabetes and isolated diabetes group. Conclusion: Presence of mild hypothyroidism in type 2 diabetes confers a protective effect with respect to glucose tolerance and redox balance whereas presence of overt hypothyroidism in type 2 diabetes has a deleterious effect. The increased incidence of hypothyroidism in diabetes, especially subclinical hypothyroidism, could be a reflection of a physiological attempt by the body to mitigate damage wrought by diabetes.

Ischemia-modified albumin levels in overt and subclinical hypothyroidism.

Free radical-mediated oxidative stress (OS) has been implicated in the pathogenesis of thyroid disorders. The ischemia-modified albumin (IMA) has been proposed as a marker of protein oxidative damage, which has been found to reflect hypoxic stress. Our aim was to evaluate IMA, malondialdehyde (MDA), and reduced glutathione (GSH) levels in patients with overt hypothyroidism (OHT) and subclinical hypothyroidism (SHT) in comparison to euthyroid controls. Albumin, IMA, IMA/albumin ratio, MDA, GSH, total cholesterol (TC), triglycerides (TG), HDL-Cholesterol were assessed in 105 subjects grouped into OHT, SHT patients, and euthyroid controls with 35 subjects in each group. MDA and IMA levels were significantly elevated while the GSH concentrations were significantly lower in OHT and SHT patients compared to controls (p < 0.01). When IMA values were normalized for albumin concentrations, the IMA/albumin ratio was also significantly elevated in both patient groups compared to controls (p < 0.01). These changes were more pronounced in the OHT group when compared to SHT group. In OHT group, thyroid-stimulating hormone (TSH) levels showed significant positive correlation with MDA (r = 0.470, p = 0.004), IMA (r = 0.530, p = 0.001), and IMA/albumin ratio (r = 0.525, p = 0.001). Both IMA (r = -0.342, p = 0.041), IMA/albumin ratio (r = -0.378, p = 0.023) showed significant negative correlation with GSH in OHT patients. No significant correlation between variables was, however, observed in SHT group. Increase of MDA and IMA levels with decreased antioxidant status indicate the presence of OS in hypothyroid patients, which was more pronounced in OHT patients. Elevated levels of IMA can be a clinically useful marker of protein oxidative damage and OS in hypothyroidism.

Metabolic Syndrome in Hypothyroid Patients

Thyroid functions affect metabolic syndrome (MetS) parameters including blood pressure, fasting plasma glucose, serum triglycerides and HDL-Cholesterol. But the relationship between MetS and thyroid functions is yet to be identified clearly. Metabolic syndrome is a state in which most features of hypothyroidism can be seen. The aim of the present study was to investigate the frequency of MetS in hypothyroid patients. Thirty one patients with overt hypothyroidism, 32 patients with subclinical hypothyroidism (SCH) and 58 euthyroid controls were enrolled in this study. NCEP-ATP III criteria was used to diagnose metabolic syndrome. Majority of the participants were in the age group of 30-40 years. Body mass index and waist circumference, blood pressure, fasting plasma glucose and serum triglycerides were found to be higher in hypothyroid patients compared to that of euthyroid controls (p&lt;0.001). On the other hand serum HDL-C was found to be significantly lower in hypothyroid patients compared to that of euthyroid controls (p&lt;0.001). Prevalence of MetS was 82.5% in the hypothyroid group and 27.6% in eythyroid controls (p&lt;0.001). No significant difference was found between SCH (81.3%) and overt hypothyroid (86.7%) groups in respect to prevalence of MetS (p&lt;0.05). The findings of the study suggest a need to investigate the presence of hypothyroidism during the management of MetS patients. DOI: http://dx.doi.org/10.3329/bjmb.v7i2.22414 Bangladesh J Med Biochem 2014; 7(2): 57-61

Impact of hypothyroidism on the development of non-alcoholic fatty liver disease: A 4-year retrospective cohort study

Background/AimsHypothyroidism is reported to contribute to the development of nonalcoholic fatty liver disease (NAFLD). We compared the risk of the development of NAFLD among three groups with different thyroid hormonal statuses (control, subclinical hypothyroidism, and overt hypothyroidism) in a 4-year retrospective cohort of Korean subjects.MethodsApparently healthy Korean subjects without NAFLD and aged 20-65 years were recruited (n=18,544) at health checkups performed in 2008. Annual health checkups were applied to the cohort for 4 consecutive years until December 2012. Based on their initial serum-free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels, they were classified into control, subclinical hypothyroidism (TSH >4.2 mIU/L, normal fT4), and overt hypothyroidism (TSH >4.2 mIU/L, fT4 <0.97 ng/dL) groups. NAFLD was diagnosed on the basis of ultrasonography findings.ResultsNAFLD developed in 2,348 of the 18,544 subjects, representing an overall incidence of 12.7%: 12.8%, 11.0%, 12.7% in the control, subclinical hypothyroidism, and overt hypothyroidism groups, respectively. The incidence of NAFLD did not differ significantly with the baseline thyroid hormonal status, even after multivariate adjustment (subclinical hypothyroidism group: hazard ratio [HR]=0.965, 95% confidence interval [CI]=0.814-1.143, P=0.67; overt hypothyroidism group: HR=1.255, 95% CI=0.830-1.899, P=0.28).ConclusionsOur results suggest that the subclinical and overt types of hypothyroidism are not related to an increased incidence of NAFLD.

Thyroid Function, Prevalent Coronary Heart Disease, and Severity of Coronary Atherosclerosis in Patients Undergoing Coronary Angiography.

This study investigated if free T4 and TSH concentrations or thyroid function categories were associated with prevalent CHD and the severity of coronary atherosclerosis in a population undergoing coronary angiography. This was a cross-sectional study including 1799 patients who were consecutively admitted and underwent coronary angiography. We evaluated the severity of coronary atherosclerosis using Gensini score. In the entire study population, free T4 level was inversely associated with prevalent CHD (OR = 0.95, 95% CI 0.91–0.99, P = 0.01) and the natural log-transformed Gensini score (ln(Gensini score)) (β = −0.03, 95% CI −0.05–−0.01, P = 0.005). The odds of CHD increased gradually across hyperthyroidism, subclinical hypothyroidism, and overt hypothyroidism groups using the euthyroid group as the reference, and the trend is borderline significant (P for trend = 0.051). When comparing to the euthyroid group, ln(Gensini score) of the overt hypothyroidism group was significantly higher (P = 0.009), but the trend was not significant (P for trend = 0.08). A significant association of thyroid function with CHD or ln(Gensini score) in euthyroid patients was not observed. The present study demonstrated an association of thyroid function with prevalent CHD and the severity of coronary atherosclerosis in a population undergoing coronary angiography. However, this association was not observed in euthyroid individuals.

Proprotein convertase subtilisin/kexin type 9 (PCSK9), soluble lectin-like oxidized LDL receptor 1 (sLOX-1) and ankle brachial index in patients with differentiated thyroid cancer.

The cardiovascular effects of short-term overt hypothyroidism are not well known. We investigated proprotein convertase subtilisin/kexin type 9 (PCSK9), soluble lectin-like oxidized LDL receptor 1 (sLOX-1) and the ankle brachial index (ABI) in thyroid cancer patients with short-term overt hypothyroidism due to thyroid hormone withdrawal (THW). Twenty-one patients requiring radioactive iodine (RAI) ablation or scanning and 36 healthy control subjects were enrolled. Patients were evaluated in the subclinical thyrotoxic phase when they were on suppressive levothyroxine therapy and in the overt hypothyroid phase due to THW for four weeks. PCSK9, sLOX-1, lipids and ABI were measured in the patient and control groups. Total cholesterol, LDL cholesterol, triglycerides and Apo B levels were increased in short overt hypothyroidism compared with the control group (p<0.001). PCSK9 levels increased before THW and after THW in the patients compared to control group (p<0.001, p=0.004, respectively). sLOX-1 levels were not different between patients with short term overt hypothyroidism and control group (p=0.27). ABI was found to be significantly decreased in patients with thyroid cancer before and after THW compared to control group (p=0.04, p=0.002 respectively). PCSK9 levels were correlated negatively with ABI (r=-0.38, p=0.004). In conclusion; our study demonstrated that patients with differentiated thyroid cancer both before and after THW which is a short term overt hypothyroid phase, had increased PCSK9 levels and decreased ABI. Short term overt hypothyroidism also leads to increased HDL, LDL, total cholesterol, Apo A and Apo B levels.

Evaluation of Metabolic Syndrome as a Complication in Thyroid Patients in Ghaziabad

Thyroid hormones play an important role in regulating energy homeostasis, glucose and lipid metabolism. Thyroid functions affect Metabolic Syndrome parameters including HDL-cholesterol, triglycerides (TG), blood pressure and plasma glucose. The impact of various degree of thyroid dysfunction on these factors, however’ continues to be debatable. Therefore present study was carried out in Santosh Medical College and Hospital. 118 patients with hypothyroidism were included in the study. Out of 118 cases 60 cases were of overt hypothyroidism and 58 of subclinical hypothyroidism. Total of 69 cases were diagnosed with Metabolic Syndrome, of which 34 (12 male, 22 female) were of overt hypothyroid group and 35 (11 male, 24 female) were of subclinical hypothyroidism. Therefore patient are at risk of developing metabolic syndrome and other related disorders i. e. Diabetes Mellitus and Vascular complications, and hence need to be followed up for aforesaid parameters of metabolic syndrome.

Altered thyroid profile in metabolic syndrome

Objectives The study was intended to access metabolic syndrome in hypothyroid patients and to investigate the association between hypothyroidism and metabolism syndrome inMeerut district.Methods The study was done on patients with symptoms of hypothyroidism or follow up cases of hypothyroidism having metabolic syndrome. T3, T4 and TSH were analysed by enzyme linked fluorescent assay (ELFA) technique using Minividas auto analyser fromBiomeriuex,France. Fasting blood sugar and lipid profile were estimated by Vitros-250 auto analyser using readymade dry chemistry kits from Ortho-Clinical diagnostics,Johnson&Johnson,USA. The data was analysed using SPSS-16 software package.Result In overt hypothyroid cases T3 values were found to be negatively correlated with waist circumference (WC), diastolic BP, FBS and TG level and positively correlated with FBS (p=0.03, r=0.24) in subclinical hypothyroidism.T4 values negatively correlated with FBS and TG level in overt hypothyroid group and with WC, systolic and diastolic BP in subclinical group. But there was significant positive correlation with TG levels (p=0.04, r = 0.23).TSH values shows negative correlation with WC, FBS, TG and HDL levels in overt hypothyroidism.Conclusion This study on metabolic syndrome in thyroid dysfunction population may help us to plan management strategies, resulting in significant reduction in cardiovascular morbidity and mortality due to metabolic syndrome.

Prevalence of hypothyroidism in patients with dyslipidemia: Tehran Thyroid Study (TTS).

Hypothyroidism is a relatively common endocrine disorder usually accompanied with changes in serum lipid profiles. The purpose of this study was to assess the association between dyslipidemia and hypothyroidism in a population-based study. In this cross-sectional study, 2,315 dyslipidemic patients, aged 20-90 years (mean age: 38.1 ± 13.2 years), were selected from among 5,760 participants of Tehran Thyroid Study and divided into 3 groups, the subclinical hypothyroid, overt hypothyroid, and euthyroid subjects, based on national reference ranges. Serum lipid profiles, free thyroxine (FT4), thyroid stimulating hormone (TSH), and thyroid peroxidase antibody (TPOAb) were measured in all subjects. In subjects with dyslipidemia and nondyslipidemia, the prevalence of subclinical was 7% and 4.1%, respectively, and for clinical hypothyroidism 3% and 1.2%, respectively. In dyslipidemic subjects, the mean low density lipoprotein-cholesterol (LDL-C) levels differed significantly (p = 0.03) among the overt hypothyroid (144.3 ± 36.1), subclinical hypothyroid (129.3 ± 39.2), and euthyroid (132.7 ± 39.0) groups. In the overt hypothyroid group, mean total cholesterol level was higher than in the normal group, but not significant. There were no differences in median triglycerides (TG) and mean high density lipoprotein-cholesterol (HDL-C) levels among the 3 groups mentioned. After adjusting for age and sex, hypothyroidism was not related to elevated serum lipid profiles in patient with dyslipidemia. In conclusion, there is significant difference in the prevalence of subclinical and clinical hypothyroidism between nondyslipidemic and dyslipidemic subjects; after adjustment for age and sex the presence of dyslipidemia did not predict the presence of hypothyroidism.

Serum H-FABP levels in patients with hypothyroidism.

Hypothyroidism (HT) has an increased risk for cardiovascular mortality and morbidity due to increased atherosclerosis. Heart-type fatty acid binding protein (H-FABP) is abundant in the cytosol of cardiomyocytes, and transports fatty acids into these cells. Although H-FABP has been shown to increase in several atherosclerotic and inflammatory conditions, there is no literature data indicating an alteration in other atherosclerotic processes such as HT. A total of 39 patients with subclinical hypothyroidism (SCH), 26 patients with overt hypothyroidism (OH), and 29 healthy subjects were enrolled in this study. Carotid artery intima media thickness (CIMT) was measured by high resolution B mode ultrasonography. H-FABP levels, thyroid function test, and biochemical tests of all subjects were measured. The associations between H-FABP and thyroid test and CIMT were examined with correlation and regression analysis. OH patients had higher H-FABP levels (mean, 6.18 ± 3.08 ng/mL) than both the SCH (mean, 3.81 ± 2.16 ng/mL) and the controls (mean, 2.12 ± 1.27 ng/mL) (P < 0.01 and < 0.001, respectively). SCH patients had increased serum H-FABP levels compared with control subjects (P < 0.01). CIMT of both OH and SCH patients was also significantly greater compared with control subjects (both of p < 0.01). H-FABP was significantly and positively correlated with age, systolic blood pressure, thyroid stimulating hormone (TSH) levels, and CIMT, and negatively correlated with fT4 levels. The H-FABP levels retained an independent and positive association with systolic blood pressure, and a negative association with fT4 levels. Serum H-FABP levels progressively increased from the control group to the OH group. This suggests that H-FABP may be an indicator of low-level myocardial damage in HT, especially when used together with CIMT. Decreasing serum fT4 levels seem also to have an effect on H-FABP levels.

Dyslipidemia and low-grade inflammation are associated with sympathovagal imbalance and cardiovascular risks in subclinical and overt hypothyroidism

Background and Aim: Hypothyroidism in both its subclinical and overt form has been reported to be associated with cardiovascular (CV) morbidities. Dyslipidemia, inflammation, and sympathovagal imbalance (SVI) contribute to CV risks. The present study has assessed role of dyslipidemia and inflammation in the genesis of SVI and hypertension status in subclinical hypothyroidism (SCH) and overt hypothyroidism (OH). Methods: Age-matched 209 females (70 euthyroids, 67 subclinical hypothyroids, and 72 overt hypothyroids) were recruited for this study. Body mass index (BMI), CV parameters, and autonomic function tests (AFT) like spectral analysis of heart rate variability (HRV), heart rate (HR) response to standing, HR response to deep breathing, and blood pressure (BP) response to isometric handgrip were assessed. Thyroid profile, lipid profile, and immunological and inflammatory markers were estimated. The independent association of the ratio of low-frequency to high-frequency (LF-HF ratio) power of HRV and the marker of SVI with various parameters were determined by multiple regression analysis. The prediction of hypertension status by LF-HF ratio was assessed by logistic regression. Results: CV and AFT parameters, lipid profile, and inflammatory marker were altered and correlated with LF-HF ratio in both SCH and OH groups. Mean arterial pressure, atherogenic index, and high-sensitive C-reactive protein had independent contribution to LF-HF ratio in both the groups. The prediction of hypertension status by LF-HF ratio was more significant in OH groups (odds ratio (OR) 2.15, CI 0.126-5.867, and P = 0.002) compared to SCH group (OR 1.90, CI 1.108-4.352, and P = 0.009). Conclusion: SVI due to sympathetic activation and vagal withdrawal occurs in SCH that progressively increases from SCH to OH. Dyslipidemia and low-grade inflammation are associated with SVI and CV risks in hypothyroidism.

Electrocardiographic and echocardiographic evidence of myocardial impairment in patients with overt hypothyroidism

ObjectiveOur aim was to evaluate cardiac function and myocardial contractility in patients with overt hypothyroidism using two-dimensional speckle tracking echocardiography (2D-STE) strain imaging and real-time three-dimensional echocardiography (RT3DE) and compare the changes at one month after starting the treatment. We also compared the P wave dispersion (Pdis) in patients with and without hypothyroidism. Subjects and methodsForty-one patients with overt hypothyroidism and forty age- and body mass index-matched healthy subjects underwent conventional echocardiography, RT3DE and 2D-STE for assessment of resting LV function. Electrocardiography (ECG) recordings were obtained and the P wave parameters were calculated. Measurements of RT3DE volumes and ejection fraction (EF) were performed. Global longitudinal strain (GLS) was calculated from 3 standard apical views using 2D-STE. ResultsPatients with overt hypothyroidism had significantly longer isovolumic contraction time (P<0.001), deceleration time (P<0.001) and isovolumic relaxation time (P<0.001). On RT3DE evaluation, none of the patients in both groups had LV systolic dysfunction with comparable LVEF and LV volumes. However, speckle tracking analysis showed that GLS was significantly reduced in the overt hypothyroidism group compared to control group (P<0.001). At one month follow-up after the treatment, GLS significantly improved in overt hypothyroidism group (P<0.001). Patients in the overt hypothyroidism group had increased Pdis compared to control group (P=0.02). ConclusionsOvert hypothyroidism may be related to impairment of LV longitudinal myocardial function, and 2D-STE is useful for the detection of early impairment. Successful treatment of overt hypothyroidism has a beneficial effect on cardiac functions. In addition, overt hypothyroidism has increased risk for atrial arrhythmias due to high Pdis value.

Carotid intima-media thickness and neutrophil/lymphocyte ratio in patient with overt and subclinical hypothyroidism

Objective: Hypothyroidism, whether overt or subclinical, has multiple effects on the cardiovascular system. Neutrophil-lymphocyte (N/L) rate is closely related to cardiovascular disorders and atherosclerosis. Our study aimed to assess N/L rate and carotid artery intima-media thickness (CIMT) in patients with overt and subclinical hypothyroidism (SCH). Methods: The study included 36 patients with SCH and 28 patients with overt hypothyroidism (OH) as well as 30 healthy controls. CIMT, thyroid hormone levels, complete blood count and lipid parameters were measured in all subjects. Correlation analysis and linear regression analysis were performed for N/L rate. Results: Mean CIMT was 0.51 ± 0.15, 0.58 ± 0.16, 0.67 ± 0.24 mm in control, SCH, and OH groups, respectively. CIMT of OH patients was high compared with control subjects (P 0.05). It was no correlation that CIMT between N/L ratio (p > 0.05). Conclusion: Neutrophil-lymphocyte rate was not found to be useful indicator of early atherosclerosis in SCH and OH patients. J Clin Exp Invest 2013; 4 (4): 463-467

Assessment of left atrial mechanical functions in thyroid dysfunction

Thyroid hormone deficiency can lead to the impairment of cardiac function. The aim of the study was to determine the left atrial (LA) mechanical function in patients with subclinical hypothyroidism (SHT) and overt hypothyroidism (OHT) and investigate associations of LA mechanical function with diastolic function. Twenty‑six patients with newly diagnosed SHT (mean age, 42.2 ±12.5 years), 21 patients with OHT (40.2 ±8.5 years) and 28 healthy volunteers (42.4 ±11.2 years) were enrolled in this study. Patients were evaluated by standard M‑mode echocardiographic measurements, mitral Doppler flow analysis, and tissue Doppler parameters at the lateral, septal, and right ventricular annuli. LA volumes were measured using the disc method, and the parameters of LA mechanical function were calculated. The active emptying volume (AEV) and active emptying fraction (AEF) were significantly higher in the OHT and SHT groups compared with controls. The passive emptying volume and passive emptying fraction were lower in the OHT and SHT groups compared with controls, but the differences were not significant. The conduit volume and the E/A ratio were significantly lower in the OHT and SHT groups compared with controls. The lateral and septal E/Em were significantly higher in the OHT and SHT groups than in the control group, but the septal Em/Am was significantly lower. Diastolic function parameters showed significant associations with AEV and AEF. LA mechanical function is impaired in patients with thyroid dysfunction. Our findings suggest that this impairment is secondary to that of the left ventricular diastolic function.

Evaluation of epicardial fat tissue thickness in patients with Hashimoto thyroiditis

Hypothyroidism, whether overt or subclinical, has multiple effects on the cardiovascular system. Epicardial fat tissue (EFT) is closely related to cardiovascular disorders and atherosclerosis. Our study aimed to assess EFT thickness and carotid artery intima-media thickness (CIMT) in patients with Hashimoto's thyroiditis (HT) displaying overt and subclinical hypothyroidism (SCH). The study included 33 patients with SCH and 24 patients with overt hypothyroidism (OH) with HT as well as 32 healthy controls. EFT thickness, CIMT, thyroid hormone levels and lipid parameters were measured in all subjects. Correlation analysis and linear regression analysis were performed for EFT thickness. Mean EFT thickness was 2·89±0·38, 3·53±0·92 and 4·56±1·61mm in control, SCH and OH groups, respectively (P<0·001). EFT thickness of OH patients was high compared with SCH and control subjects (P<0·01 and <0·001, respectively). CIMT of OH patients was high compared with SCH and control subjects (P<0·01 and <0·001, respectively). In addition, EFT was significantly thicker in SCH patients than in controls (P<0·05). Correlation analysis showed that EFT thickness was significantly positively correlated with CIMT, age, body mass index, systolic blood pressure, thyroid-stimulating hormone, total and LDL cholesterol and triglyceride and negatively correlated with free T4. In the regression analysis, EFT thickness retained its independent and positive association with CIMT, patient group (particularly OH) and systolic blood pressure. Epicardial fat tissue thickness may be a useful indicator of early atherosclerosis in SCH and OH patients with HT.

Glycosylation of sera thyroglobulin antibody in patients with thyroid diseases

Thyroglobulin antibody (TgAb) is an important autoantibody in thyroid diseases, which is a glycoprotein, predominantly of IgG class. Glycosylation of the IgG-Fc contributes to many effector functions exhibited by antibodies. The aim of our study was to investigate the glycosylation of sera TgAb in patients with different thyroid diseases. Sera from 146 patients were collected and divided into four groups: Hashimoto's thyroiditis (HT, n=90), Graves' disease (GD, n=20), papillary thyroid carcinoma (PTC, n=17), and PTC with histological lymphocytic thyroiditis (PTC-T, n=19). HT patients were further divided into euthyroidism and subclinical and overt hypothyroidism groups. Lectin-ELISAs were performed to detect the relative amount of core fucose, terminal galactose, and sialic acid on each TgAb respectively. Among HT, GD, and PTC groups, HT patients had significantly lower core fucose content on TgAb than the other two groups; an increasing trend of sialylation was found in PTC sera (P=0.076) compared with HT groups. PTC-T patients had significantly higher sialylated TgAb than HT and GD patients, and no significant difference was found between PTC and PTC-T. There was no significant difference in the three carbohydrate residue contents on sera TgAb among HT subgroups. In all the patients, negative correlation was found between sialic acid content and TgAb IgG levels (r=-0.736, P<0.001). Our study showed that glycosylation of sera TgAb varied in different thyroid diseases and it might be involved in pathogenesis of thyroid disorders.

Prevalence, Associated Risk Factors and Effects of Hypothyroidism in Pregnancy: A Study from North India

Background and Objective: There is a controversy regarding universal versus targeted screening for hypothyroidism during pregnancy. We studied the prevalence and the associated risk factors of hypothyroidism. The secondary objective of the study was to compare the maternal and perinatal outcomes in overt and subclinical hypothyroidism. Methods: We screened 1,005 antenatal patients for hypothyroidism with a thyrotropin assay. Patients diagnosed with hypothyroidism were further tested for anti-thyroid peroxidase antibodies and free thyroxin to determine the cause and type (overt or subclinical) of hypothyroidism. Maternal and perinatal outcomes were compared in the overt, subclinical and euthyroid groups. Results: The overall prevalence of hypothyroidism was 6.3% (overt 2.9% and subclinical 3.4%). Thirty-four (3.4%) new hypothyroid cases could be detected by universal screening. The risk factors for thyroid dysfunction were not significantly different in the screen-positive versus screen-negative patients except for excessive weight gain (p = 0.00). Targeted screening could have missed one third of subclinical hypothyroid cases. Gestational hypertension was significantly greater in the overt hypothyroid group (p = 0.007), and more patients required induction in this group (p = 0.013) but other maternal complications and perinatal outcomes were similar. Conclusion: We recommend universal screening for hypothyroidism in pregnancy in our population, as the prevalence of hypothyroidism is high.

Reassessment of elicitation of myoedema in evaluation of overt hypothyroidism: A pilot study

Introduction:There is a need to reassess the significance of myoedema in evaluation of overt hypothyroidism in the current day clinical practice. It is commonly checked for by flicking across the biceps belly expecting a transient mound at the points of tactile stimuli with mild pressure.Aim and Objective:To assess elicitation of myoedema in overt hypothyroidism (defined arbitrarily as TSH >50 mIU/L in primary hypothyroidism and fT4 <0.6 ng/dl in secondary hypothyroidism).Results:The 28 primary overt hypothyroid (OH) patients were divided into three groups as mild, moderate, and severe depending on TSH levels as those with 50-100, 100-150, and >150 mIU/L. Myoedema was elicited in 8 of 13 in the severe OH group, in 2 of 7 in moderate OH group and in 1 of 8 in the mild OH group. In the group of secondary hypothyroidism, myoedema was elicitable in one of two patients. The odds ratio for presence of both myoedema and clinical features of myopathy in a group of overt hypothyroid patients with TSH >150 mIU/L as compared to <150 mIU/L was 17.5. Similarly, the odds ratio for the presence of only myoedema was 6.4 while the odds ratio for presence of only clinical features of myopathy was 3.67. While the odds ratios involving presence of myoedema neared statistical significance, that with the presence of clinical features of myopathy alone did not.Conclusion:Examination for eliciting myoedema is useful when evaluating a case of overt hypothyroidism.

Characteristics of anemia in subclinical and overt hypothyroid patients

Thyroid hormones stimulate directly or indirectly growth of erythroid colonies through erythropoietin. Anemia is often the first sign of hypothyroidism. Hypothyroidism can cause a wide variety of anemic disorders. Numerous mechanisms are involved in the pathogenesis of these anemias that can be microcytic, macrocytic and normocytic. We designed this study to investigate the anemia frequency and if present, etiology of anemia in hypothyroid patients. 100 patients with overt hypothyroid, 100 patients with subclinical hypothyroid, and 200 healthy controls were enrolled in this study. Overt hypothyroidism diagnosis is done when elevated TSH and low levels of free T4 and/or free T3 have been observed. Subclinical hypothyroidism is defined as elevated serum TSH with normal free T(4) and free T(3) levels. Peripheral smears of the anemic patients were examined. Anemia prevalence was 43% in the overt hypothyroid group, 39% in the subclinical hypothyroid group, and 26% in the control group (p=0.0003 and p=0.021 respectively related to controls). Thus, the frequency of anemia in subclinical hypothyroidism is as high as that in overt hypothyroidism. There was no difference between the hypothyroid groups in terms of anemia. Vitamin B12, Fe, and folic acid were similar between these groups. According to our findings, anemia of chronic disease is the most common type of anemia in hypothyroid patients. Suspicion of hypothyroidism should be considered in anemias with uncertain etiology.