Subclinical Hyperthyroidism Group Research Articles

Assessment of Cerebral Arterial Flow Volume Changes with Carotid Vertebral Artery Duplex Doppler Ultrasound in Young-Middle-aged Subclinical Hashimoto Thyroiditis Patients.

To demonstrate cerebral arterial flow volume changes during the hypothyroid, euthyroid, and hyperthyroid phases and comparing between laboratory findings and cerebral arterial flow changes with carotid-vertebral duplex Doppler ultrasound (CVA-DUSG) in subclinical Hashimoto thyroiditis (HT) patients. According to the TSH level, 3 groups were constructed between patient cases. Group 1 (n=29) was the subclinical hyperthyroid group. In this group, the TSH level was between 0.0005 and 0.3 IU/ml. Group 2 (n=175) was the euthyroid group. TSH level in this group was between 0.3 and 4.2 IU/ml. Group 3 (n=76) was the subclinical hypothyroid group. In this group, the TSH level was above 4.2 IU/ml. The control-group (group 4) (n=71) included healthy people. In this group, the TSH level was between 0.3 and 4.2 IU/ml. After obtaining at least three consecutive waves from the bilateral internal cerebral artery and bilateral vertebral artery, volume flows were calculated using CVA-DUSG. Volume flows were calculated as peak systolic velocity + end diastolic velocity/2 × mean arterial diameter. The mean ICA(Internal Carotid Artery) and VA(Vertebral Artery) diameter was measured per ICA and VA. Total cerebral artery flow volume was defined as right ICA + right VA flow volume and left ICA + left VA flow volume. We also demonstrated topographic cerebral artery blood flow changes. Total ICA flow volume was used to assess the anterior part of the brain, total VA flow volume was used to evaluate the posterior part of the brain, right ICA + right VA flow volume was used to assess the right part of the brain, and left ICA + left VA flow volume was used to verify the left part of the brain. There were significant differences between RVA(Right Vertebral Artery) flow volume, LICA (Left Internal Carotid Artery) flow volume, total flow volume, TSH, and T3 and T4 levels in all groups according to the Dunn's multiple comparison test.(p<0.001) Mean TSH level was 0.03 (0.005-0.06) IU/ml in group 1, 2.8 (1.8-3.97) IU/ml in group 2, 7.32 (6.14-9.93) IU/ml in group 3, and 1.76 (1.17-2.49) IU/ml in the control group. The mean T3 level was 4.18 (3.55-5.38) in group 1, 2.88 (2.63-3.16) in group 2, 2.82 (2.49-3.15) in group 3, 3.14 (2.92-3.15) in the control group. The mean T4 level was 1.92 (1.29-2.5) in group 1, 1.16(1.03-1.31) in group 2, 1.01 (0.91-1.16) in group 3, 1.12 (0.97-1.30) in the control group (group 4). Mean total flow volume was 793 (745-898) ml/min in group 1, 742 (684.25-822.5) ml/min in group 2, 747 (692-824) ml/min in group 3, and 700 (673-675) ml/min in the control group. We also demonstrated topographic cerebral arterial volume flow changes with CVA-DUSG. There was a significant difference among all groups in the right and anterior parts of the brain (p < 0.001), and there was a significant difference between groups 1 and 4 in the left part of the brain (p = 0.009). This study demonstrated that total cerebral arterial volume flow increased in the hyperthyroid phase of subclinical HT cases without any internal carotid and vertebral artery diameter changes compared with the euthyroid and hypothyroid phases of subclinical HT and healthy cases. We also verified topographic cerebral arterial blood flow changes in subclinical HT cases with a real-time, easily applicable modality (CVA-DUSG) that does not include X-ray or contrast agents. There was a significant difference between all groups in the right and anterior parts of the brain and there was a significant difference between groups 1 and 4 in the left part of the brain.

Four-dimensional speckle tracking echocardiography and fragmented QRS in detection of early left ventricular systolic dysfunction in patients with subclinical hyperthyroidism.

Thyroid disorders are associated with many cardiovascular risk factors. The importance of thyroid hormones in the pathophysiology of heart failure is underlined by the European guidelines of the European Society of Cardiology. However, the role of subclinical hyperthyroidism (SCH) in subclinical left ventricular (LV) systolic dysfunction is not entirely clear. This cross-sectional study included 56 SCH patients and 40 healthy volunteers. The 56 SCH group was divided into two subgroups depending on the presence of fragmented QRS (fQRS). In both groups, left ventricular global area strain (LV-GAS), global radial strain (GRS), global longitudinal strain (GLS), and global circumferential strain (GCS) were obtained with four-dimensional (4D) echocardiography. GAS, GRS, GLS, and GCS values were significantly different in SCH patients and in healthy volunteers. GLS and GAS values were lower in the fQRS+ than in the fQRS- group (-17.06 ± 1.00 vs. -19.08 ± 1.71, p < .001, and -26.61 ± 2.38 vs. -30.61 ± 2.57, p < .001, respectively). ProBNP was positively correlated with LV-GLS (r = 0.278, p = .006) and LV-GAS (r = 0.357, p < .001). Multiple linear regression analysis showed that fQRS was an independent predictor of LV-GAS. 4D strain echocardiography may be helpful for the prediction of early cardiac dysfunction in patients with SCH. The presence of fQRS may be an indicator of subclinical LV dysfunction in SCH.

Evaluation of Bone Turnover Markers Such as Osteoprotegerin, Sclerostin and Dickkopf-1 in Subclinical Hyperthyroidism.

In this study, it was aimed to assess effects of subclinical hyperthyroidism (SH) on bone metabolism using osteoprotegerin (OPG), sclerostin, Dickkopf-1 (DKK1) and biochemical parameters. This cross-sectional prospective study included 40 patients with SH and 40 euthyroid controls. Serum OPG, sclerostin, DKK-1, type-1 procollagen, C-terminal polypeptide (CTx) and 24-hours urine N-terminal telopeptide (NTx) were measures using ELISA kit. Bone mineral density measurements were performed using dual energy X-ray absorptiometry (DEXA). Risk for 10-years hip and major fracture was estimated by Turkish version of FRAX. No significant difference was detected in age, gender, body mass index, smoking and menopause rates between SH and control groups. The risk for 10-years hip fracture and major osteoporotic fracture were estimated as 4.45% and 0.55% in SH group, respectively. The OPG levels were significantly lower in patients with SH than controls (P = 0.017). No significant difference was detected in other bone formation and degradation parameters. No significant correlation was detected between OPG level and risk for major osteoporotic fracture (P > 0.05); however, a negative correlation was detected between OPG level and risk for hip fracture (rho = 0.233; P = 0.038). Serum OPG is markedly affected in patients with SH. In addition, OPG seemed to be associated with osteoporotic fracture risk. Available data show that SH is significantly associated with risk for fracture; thus, it is important to assess risk for fracture in patients with SH.

Maternal subclinical hyperthyroidism and adverse pregnancy outcomes considering the iodine status: Tehran thyroid and pregnancy study

BackgroundUnlike overt thyroid diseases, the impacts of subclinical thyroid dysfunction, especially subclinical hyperthyroidism (SH), on adverse pregnancy outcomes are inconclusive. ObjectiveWe aimed to investigate the effect of maternal SH on adverse maternal and neonatal outcomes based on urinary iodine concentration (UIC). MethodsA secondary analysis was run on data collected in the Tehran Thyroid and Pregnancy study (TTPs). We used the data of 131 women with SH and 1650 cases of euthyroid. Serum levels of thyroid-stimulating hormone (TSH), thyroxine (T4), free thyroxine index (FT4I), and thyroid peroxidase antibody (TPOAb) were assessed at the first prenatal visit. A generalized linear regression model was applied to identify the effect of SH on the pregnancy outcomes based on UIC, and the effects were estimated with a 95% confidence interval. ResultsPreterm delivery was observed in 12.3% of women with SH and 6.7% of those with euthyroid (P = 0.03). Women with TSH< 0.3 mIU/L had a higher odds of preterm delivery than those with TSH≥ 0.3 regardless of urine iodine cut-off [OR= 2.27; 95% CI: (1.15, 4.48), p = 0.02]. Among those with UIC levels≥ 150 μg/L, the odds ratio of preterm delivery was 4.61 folds higher in the SH group compared to those with euthyroid [95%CI: (1.36, 15.71), p = 0.01)]. No significant difference between these two study groups was found in Neonatal Intensive Care Unit admission. Moreover, the results revealed no statistically significant difference in the means of neonatal anthropometric parameters in the SH and euthyroid groups in none of the subgroups of UIC (<150 or ≥150 µg/l). ConclusionsAccording to our results, maternal SH appears to be a risk factor for preterm delivery. This effect is more pronounced in women with higher UIC than those with lower UIC.

Protective effects of Portulaca oleracea and vitamin E on cardiovascular parameters in rats with subclinical hyperthyroidism

ABSTRACT Introduction Subclinical hyperthyroidism (SHT) is an endocrine disorder that is associated with abnormalities in heart structure and function. Oxidative stress plays an important role in the pathophysiology of cardiac disorders caused by SHT. Portulaca oleracea (P. Oleracea) is a herbaceous plant with many pharmacologic effects including antioxidant, and anti-inflammatory properties. In the present study, the effects of Portulaca oleracea and vitamin E on the biochemical, hemodynamic, and functional parameters of the cardiac tissue was studied in rats with subclinical hyperthyroidism. Methods Fifty-six male rats were divided into seven groups: 1-Control group: daily injection of saline, 2-SHT group: daily injection of levothyroxine sodium (LS) (20 µg/kg), 3- T4+Po groups were given LS and P. oleracea (100, 200, and 400 mg/kg in drinking water), 4- the T4+vit E groups received LS and a daily injection of vitamin E (100 and 200 mg/kg). Cardiac index, systolic blood pressure (SBP), also malondialdehyde and total thiol levels were measured in cardiac tissue. Results SBP and maximum dP/dt were significantly increased and minimum dP/dt was significantly decreased in SHT group. In P. oleracea groups, maximum dP/dt were significantly reduced and minimum dP/dt was increased. Malondialdehyde levels and cardiac index in groups receiving vitamin E and P. oleracea were significantly decreased. Maximum dP/dt was decreased in the group receiving LS+vitamin E. Minimum dP/dt was significantly higher in group received LS+ vitamin E. Conclusion This study showed that Portulaca oleracea has a positive effect on cardiac dysfunction caused by subclinical hyperthyroidism.

Menopausal Impact on the Association Between Thyroid Dysfunction and Lipid Profiles: A Cross-Sectional Study.

BackgroundBoth dyslipidemia and thyroid dysfunction have a high prevalence rate and are important risk factors for cardiovascular diseases. However, the relationship between blood lipids and thyroid dysfunction is still controversial. This study aims to analyze the blood lipids in people with different thyroid functions.MethodsA total of 80937 adults were included in this population-based cross-sectional TIDE survey, which collected demographic and clinical data on thyroid function, blood lipid levels and other metabolic indicators. After screening, the final analysis included 10,747 participants, who were divided into hypothyroidism (n=311), subclinical hypothyroidism (n=5015), hyperthyroidism (n=203), subclinical hyperthyroidism (n=118) and control (n=5100) groups. The risk of dyslipidemia was analyzed by a logistic regression model and divided into groups of female menopausal.ResultsAfter full adjustment, significant associations were found between hypothyroidism and hypertriglyceridemia. Subclinical hypothyroidism was associated with a significantly higher risk of hypertriglyceridemia and hyper-low density lipoprotein cholesterolemia. Hyperthyroidism was significantly correlated with a reduced risk of hypercholesterolemia and hyper-low density lipoprotein cholesterolemia but positively correlated with the risk of low-high density lipoprotein cholesterolemia. There was no significant association between subclinical hyperthyroidism and blood lipids. Hypothyroidism increased the risk of hypertriglyceridemia in both premenopausal and postmenopausal females. Subclinical hypothyroidism was significantly associated with increased hypertriglyceridemia and low-high density lipoprotein cholesterolemia in premenopausal females. Hyperthyroidism was significantly associated with a reduced risk of hypercholesterolemia and hyper-low density lipoprotein cholesterolemia in premenopausal females and an increased risk of low-high density lipoprotein cholesterolemia in postmenopausal female.ConclusionAbnormal thyroid function has an important effect on blood lipids and is closely related to female menopause.

Association of subtle alterations in thyroid function with presarcopenia in patients with type 2 diabetes mellitus.

ABSTRACTAims/IntroductionTo investigate the association of subtle alterations in thyroid function with presarcopenia among patients with type 2 diabetes mellitus.Materials and MethodsA total of 1,865 adult patients with type 2 diabetes mellitus were enrolled in this cross‐sectional study, excluding patients with overt thyroid dysfunction. Skeletal muscle mass measured by dual energy X‐ray absorptiometry was used to assess presarcopenia. Logistic regression models were used to estimate the effects of thyroid hormones on presarcopenia, and subgroup analyses were carried out in different strata of age, sex and body mass index, respectively.ResultsCompared with the euthyroid group (Euthy), the subclinical hyperthyroidism group had an increased odds of presarcopenia (multivariate‐adjusted odds ratio 1.99, 95% confidence interval 1.09–3.63), but the subclinical hypothyroidism group did not (P > 0.05). In the subclinical hyperthyroidism group, age and body mass index <24 kg/m2 were independent risk factors for presarcopenia. In the overall Euthy group, an increased odds of presarcopenia was correlated with the elevated free thyroxine : free triiodothyronine ratio (all P for trend <0.05), whereas not with increment in free triiodothyronine level (P for trend >0.05). Additionally, in Euthy subgroup analyses stratified by middle‐age, sex and body mass index, a similar association was noted (all P for trend <0.05), but not in the older‐aged patients (P for trend >0.05).ConclusionsSubclinical hyperthyroidism was an independent risk factor for presarcopenia in patients with type 2 diabetes mellitus, but subclinical hypothyroidism was not. In the Euthy group with type 2 diabetes mellitus, a high free thyroxine : free triiodothyronine ratio was a good index of presarcopenia in addition to older age.

Clinical Implication of TSH Screening in Venous Thromboembolism Patients

Background: Venous thromboembolism (VTE) that have significant morbidity and mortality for patients in the community and hospital. A recent meta-analysis found a significantly increased risk of incidence VTE among patients with hyperthyroidism compared to patients without hyperthyroidism. To our knowledge, no study has attempted to explore whether screening for TSH levels in VTE patients leads to a diagnosis of undiagnosed thyroid dysfunction as VTE could be the first presenting symptom. Method: We conducted a retrospective cohort study and analyzed data of all patients treated at University Medical Center, Lubbock, Texas in 18-85 years of age with a diagnosis of DVT and/or PE in 2019. Qualitative chart review to identify cases of clinically significant TSH screening in VTE patients that leads to thyroid dysfunction diagnosis. Associations between variables tested using Student’s t-test, chi-square, and Fisher’s exact test. Results: Of total of 533 participants with diagnosis of VTE in 2019, 85 participants were included in the study. Seven participants (8.24%) were found to have high TSH level (>4.2 mIU/mL). None of them was found to have low level of TSH. Participants in high TSH group were more likely to be female (71.43%) and Caucasian (71.43%). In high TSH group patients tended to have both PE and DVT diagnosis at the same admission (71.43%). Weight and BMI were significance higher than those with normal TSH level. Segna et al conducted a prospective multicenter cohort study on association between thyroid dysfunction and venous thromboembolism. The study measure thyroid hormones and thrombophilic biomarkers at 1 year after the acute VTE and follow for the recurrent VTE (rVTE). They found that after 20.8 months of follow-up, 9% developed rVTE. However, none of them was found in subclinical hyperthyroidism group. Furthermore, in their multi-variate analyses, the hazard ratio for rVTE was 0.80 (95%CI 0.23-2.81) subclinical hyperthyroidism compared with euthyroid participants. They concluded that subclinical hyperthyroidism may be associated with lower rVTE risks. Similarly, with Liviu study found hyperthyroidism was not associated with an increased risk of VTE. Qualitative chart review in our patients with high TSH resulted that none of them had history of tobacco use. One participant was on birth control pills with the history of cervical carcinoma. Conclusion:The association of thyroid dysfunction and the development of VTE is debated on the literature review. In our study we found multiple patients with high TSH level (8.24%) in VTE patients with no prior history of thyroid dysfunction. TSH could play an important role in hypercoagulable state. Subclinical hypothyroidism and/or hypothyroidism may induce a prothrombotic event. However, larger cohort studies with higher prevalence of high TSH participants are needed to prove a relationship between TSH level and VTE events.

Subclinical Hyperthyroidism Could Predict Poor Outcomes in Patients With Acute Ischemic Stroke Treated With Reperfusion Therapy

Background: Evidence for the effect of subclinical thyroid dysfunction on the prognosis of patients suffering from acute ischemic stroke and receiving reperfusion therapy remains controversial. We aimed to investigate the association between subclinical thyroid dysfunction and the outcomes of patients with acute ischemic stroke who were treated with reperfusion therapy.Methods: One hundred fifty-six consecutively recruited patients with acute ischemic stroke receiving reperfusion therapy (intravenous thrombolysis, intraarterial thrombectomy and combined intravenous thrombolysis and intraarterial thrombectomy) were included in this prospective observational study. We divided patients with subclinical thyroid dysfunction into the following 2 groups and defined a euthyroid group: subclinical hyperthyroidism (a thyroid-stimulating hormone level <0.35 μU/mL), subclinical hypothyroidism (a thyroid-stimulating hormone level >4.94 μU/mL), and a euthyroid state (0.35 μU/mL ≤ thyroid-stimulating hormone level ≤ 4.94 μU/mL). Patients with overt thyroid dysfunction were excluded. The primary outcome was functional disability at 3 months (modified Rankin Scale, mRS), and the secondary outcome was successful reperfusion. A multivariate analysis was performed to evaluate the associations between subclinical thyroid dysfunction and the primary and secondary outcomes.Results: The subclinical hyperthyroidism group appeared to have poor functional outcomes, but the differences were not significant. However, compared with patients in the euthyroid state, patients with subclinical hyperthyroidism had an increased risk of poor functional outcomes at 3 months after a stroke (adjusted odds ratio [OR] 2.50, 95% confidence interval [CI] 1.01–6.14 for a mRS score of 3 to 6) and a decreased rate of successful reperfusion after reperfusion therapy (OR 0.13, 95% CI 0.04–0.43).Conclusion: Subclinical hyperthyroidism may be independently associated with a poor prognosis at 3 months and unsuccessful reperfusion in patients with acute ischemic stroke receiving reperfusion therapy.

Hyperthyroidism influences renal function.

While the effects of hypothyroidism on renal function have been studied extensively, there is less information concerning the effect of hyperthyroidism. We aimed to elucidate the effect of overt and subclinical hyperthyroidism, on estimated glomerular filtration rate (eGFR) with large number of patients treated for hyperthyroidism and after euthyroidism was achieved. A total of 433 consecutive overt and subclinical hyperthyroid patients were included in the study. We assessed serum fT3, fT4, TSH, BUN, creatinine, and eGFR measurements during both hyperthyroid and euthyroid states of the same patients. The eGFR was calculated using the simplified modification of diet in renal disease (MDRD) Formula. Among these patients, 367 had overt, and 66 had subclinical hyperthyroidism. fT3, fT4, and eGFR measurements decreased, meanwhile BUN, creatinine and TSH levels increased significantly after euthyroidism was achieved (p < 0.0001 for all). The correlation analyses revealed that eGFR in hyperthyroid state (eGFRh) and fT3 in hyperthyroid state (fT3h) (r = 0,210, p < 0,0001), and fT4 in hyperthyroid state (fT4h) (r = 0,176, p < 0,0001) were significantly correlated. ∆GFR did not differ between overt hyperthyroid group and subclinical hyperthyroid group. We observed a significant decline in eGFR measurements after the patients became euthyroid. Some of these patients had lower values than 60 mL/min/1.73 m2, which mean that hyperthyroidism may be masking mild renal failure.

Association of Overt and Subclinical Hyperthyroidism During Weeks 4-8 with Adverse Pregnancy Outcomes.

Background: Although increasing data suggest that hyperthyroidism is associated with adverse pregnancy outcomes, there are only a few reports with different conclusions on whether the mild transient reduction in thyrotropin (TSH) with or without free thyroxine (FT4) elevation during the early stage of pregnancy also causes adverse pregnancy outcomes. Subjects and Methods: We analyzed data from 3,783 women in this study from August 2011 to December 2013. Participants completed a questionnaire survey. Samples of blood were obtained in the 4th-8th week of pregnancy and their TSH, FT4, thyroid peroxidase antibody, and thyroglobulin antibody were measured. We divided the participants into overt hyperthyroidism group (OHG), subclinical hyperthyroidism group (SHG), and control group based on their blood results and followed up on their pregnancy outcomes. Results: (1) The serum level of FT4 in the SHG was much higher than the control group (p < 0.05). No difference was found in the TSH between the OHG and SHG. The positive rate of autoimmune thyroid antibodies in the OHG (25.6%) was significantly higher than that in the SHG (14.2%) and control group (13.9%) (p < 0.05), whereas there was no difference between the SHG and control group. (2) The SHG had a lower incidence of miscarriage (1.7% vs. 7.2%; OR = 0.218, p = 0.016) than the control group, and the OHG had a higher incidence of placenta previa (3.3% vs. 0.8%; OR = 4.366, p = 0.039) than the control group. (3). We used a binary logistic regression to take other factors into consideration and found that subclinical hyperthyroidism was associated with a lower risk of abortion (OR = 0.206; 95% CI = 0.050-0.840; p = 0.028) but higher risk of preeclampsia (OR = 5.143; 95% CI = 1.463-18.076; p = 0.011) and placental abruption (OR = 4.676; 95% CI = 1.017-21.509; p = 0.048), and overt hyperthyroidism may increase the incidence of placenta previa (OR = 4.193; 95% CI = 1.222-14.382; p = 0.023). Conclusions: Subclinical hyperthyroidism during weeks 4-8 of pregnancy may be associated with the decreased incidence of abortion but might be a risk factor for preeclampsia and placental abruption. Meanwhile, pregnancy with overt hyperthyroidism may be an independent risk factor for placenta previa.

Detection of Blood Lipids, Homocysteine and Endothelin in Patients with Hypothyroidism and Subclinical Hypothyroidism and Its Clinical Significance

Objective To discuss the changes of blood lipids, homocysteine (Hcy) and endothelin (ET) levels in patients with hypothyroidism and subclinical hypothyroidism, and to explore their clinical significance. Methods The authors choose 255 cases of hypothyroidism, 274 cases of subclinical hypothyroidism and 130 cases of the control group to test serum TC, TG, HDL, LDL, LPa, Hcy and ET. The correlation were analyzed. Results The level of TC, TG, LDL of hyperthyroidism group and subclinical hyperthyroidism group are higher than the control group, HDL is lower than the control group. The level of TC, TG, LDL of hyperthyroidism group is higher than subclinical hyperthyroidism group, HDL is lower than subclinical hyperthyroidism group. The level of Hcy of hyperthyroidism group and subclinical hyperthyroidism group are higher than the control group. The level of Hcy of hyperthyroidism group is higher than subclinical hyperthyroidism group. The level of ET of hyperthyroidism group is lower than the control group and subclinical hyperthyroidism group. Conclusions All of blood lipids, Hcy and ET participate in the development process of hypothyroidism and subclinical hypothyroidism which is of great value in predicting the transition of thyroid dysfunction and the occurrence of adverse consequences.

Significance of Serum IL-2, IL-6 and IL-8 Detection in Patients with Hyperthyroidism and Subclinical Hyperthyroidism

Objective: This paper is to explore the relationship between IL-2, IL-6, IL-8 and the development of hyperthyroidism and subclinical hyperthyroidism. Methods The serum levels of IL-2, IL-6 and IL-8 were determined in 251 cases of hyperthyroidism, 242 cases of subclinical hyperthyroidism and 130 cases of normal control. Results The level of IL-2 in hyperthyroidism group was significantly lower than that in the control group (P<0.01), and the levels of IL-6 and IL-8 were significantly higher than those in the control group (P<0.01); The level of IL-2 in subclinical hyperthyroidism group was lower than that in the control group (P<0.05), and the levels of IL-6 and IL-8 were higher than those in the control group (P<0.05). The level of IL-2 in hyperthyroidism group was lower than that in subclinical hyperthyroidism group, and the level of IL-6 and IL-8 were higher than those in subclinical hyperthyroidism group. The two groups of IL-2 were negatively correlated with serum FT3, FT 4, TT3, and TT4, and IL-6 and IL-8 were positively correlated with serum FT3, FT 4, TT3, and TT4. Conclusions IL-2, IL-6, and IL-8 all participated in the development process of hyperthyroidism and subclinical hypothyroidism, which contributed to the early discovery of subclinical hyperthyroidism.

Analysis of the Levels of Endothelin, Homocysteine and Blood Lipid in Patients with Clinical and Subclinical Hyperthyroidism

[Objective] To discuss the changes of endothelin (ET), homocysteine (Hcy) and blood lipids levels in patients with hyperthyroidism and subclinical hyperthyroidism, and to explore their clinical significance. [Methods] The authors choose 251 cases of hyperthyroidism, 242 cases of subclinical hyperthyroidism and 130 cases of the control group to test ET, Hcy, TC, TG, HDL, LDL and LPa. [Results] The level of ET of Hyperthyroidism group is higher than subclinical hyperthyroidism group and the control group. The level of ET of subclinical Hyperthyroidism group is higher than the control group(P<0.05). The level of Hcy of Hyperthyroidism group and subclinical Hyperthyroidism group was lower than the control group(P<0.05). The level of TG, TC, LDL, LPa of subclinical Hyperthyroidism group are lower than the control group(P<0.05). The level of TG, TC, HDL, LDL, LPa of Hyperthyroidism group are lower than the control group and subclinical hyperthyroidism group (P<0.05). [Conclusions] All of ET, Hcy and lipids participate in the occurrence and development process of hyperthyroidism and subclinical hyperthyroidism. Monitoring the change of related indexes is helpful to predict the transformation of subclinical hyperthyroidism to hyperthyroidism and the occurrence of cardiovascular disease.

Is Subclinical Thyroid Dysfunction Associated With with Coronary Heart Disease

Introduction: Previous cohort studies reported contradictory data on the association between subclinical thyroid dysfunction and coronary heart disease (CHD). Regarding this, the present study was conducted to illuminate this relationship. Materials and Methods: For the purpose of the study, 3,066 participants employed in a study conducted by Azizi et al. aged ≥ 20 years were subjected to thyroid function tests every 3 years over a mean follow-up of 10 years. After the exclusion of the subjects with CHD and those consumed thyroid, anti-thyroid, or corticosteroid preparations, 2,144 subjects remained for analysis and followed up for CHD events in the next 10 years. Results: At the baseline, 1929, 139, and 76 subjects had euthyroid, subclinical hyperthyroid, and subclinical hypothyroid, respectively. No CHD event occurred in the subclinical hypothyroid group. After the adjustment of all confounders, the subclinical hyperthyroid group had the hazard ratio of 1.01 for CHD with a 95% confidence interval of 0.36-2.85. Conclusions: The 10 year follow-up of subjects with subclinical thyroid disease revealed no relationship between CHD and subclinical thyroid disorders.

Arterial stiffness in hyperthyroid patients is deteriorated due to thyroid hormones

ABSTRACT Objective The aim of this study is to evaluate and compare arterial stiffness, which is an independent risk indicator for cardiovascular diseases (CVDs), between patients with overt hyperthyroidism, subclinical hyperthyroidism, euthyroidism by antithyroid therapy and healthy volunteers with pulse wave analysis (PWA). Subjects and methods A total of 102 volunteers were included in the study (30 in the overt hyperthyroid group, 28 in the subclinical hyperthyroid group and 14 with euthyroidism by antithyroid therapy and 30 healthy). The arterial stiffness measurements of the participants in the study were performed with the Mobil-O-Graph PWA device (I.E.M. GmBH, Stolberg, Germany), which makes cuff based oscillometric measurement from the brachial artery. Results Systolic blood pressure, pulse rate, central systolic blood pressure, cardiac output, heart rate-corrected augmentation index (Aix@75) and pulse wave velocity (PWV) measurements were significantly higher in the hyperthyroid group than in the control group. The heart rate and PWV in the subclinical hyperthyroid group were significantly higher than the control group. In the euthyroid group, systolic blood pressure, central systolic blood pressure, cardiac output, cardiac index and PWV were found significantly higher than the control group. There was also a negative correlation between Aix@75 and thyroid-stimulating hormone (TSH), and a positive correlation between Aix@75 and free thyroid hormones. Conclusion In our study, we observed that the arterial stiffness was adversely affected by an overt or subclinical increase in thyroid hormones and this correlated with thyroid hormone levels. We recommend that PWV measurement, which is a simple method for detecting CVD risk, can be used in these patients.

The relationship between subclinical thyroid dysfunction and the risk of fracture or low bone mineral density: a systematic review and meta-analysis of cohort studies.

Our aim was to assess the risk of fractures or low bone mineral density (BMD) associated with subclinical thyroid dysfunction among cohorts. We systematically searched Medline (via PubMed), EMBASE, Cochrane Library, Web of Science, CENTRAL and SinoMed up to 31 July 2016 to identify cohort studies which have analyzed associations between subclinical thyroid dysfunction and fracture or BMD. A total of 19 population-based cohorts including 79,368 participants with relationships between subclinical thyroid dysfunction and fractures or BMD were identified as eligible for this meta-analysis. Subclinical hypothyroidism was associated with relative risks (RRs) of 1.34 (95% confidence interval [CI] 1.14, 1.58; I 2=32%) for hip fracture, 1.27 (95% CI 1.02, 1.58; I 2=51.9%) for any location of fracture, and 1.25 (95% CI 1.04, 1.50) for forearm fracture. Subclinical hyperthyroidism was associated with RRs of 1.71 (95% CI 1.06, 2.76; I 2=0.0%) for spine fracture, 1.20 (95% CI 1.03, 1.39; I 2=0.0%) for non-spine fracture, 1.44 (95% CI 1.21, 1.71; I 2=0.0%) for hip fracture, and 1.38 (95% CI 1.21, 1.58; I 2=0.0%) for any location of fracture. Subgroup analysis was conducted according to whether thyroid/anti-thyroid drug users were excluded or not and the results were similar. The change in BMD at the hip (weighted mean difference [WMD]=-0.060, 95% CI -0.116, -0.004; I 2=0.0%) and femoral neck (WMD=-0.046, 95% CI -0.077, -0.015; I 2=0.0%) was significantly decreased in the subclinical hyperthyroidism group compared with the euthyroidism groups in females. We failed to find any associations between the change in BMD and subclinical hypothyroidism. The overall quality of evidence was low in all outcomes. Subclinical hyperthyroidism and subclinical hypothyroidism were associated with an increased risk of fractures. Although subclinical hyperthyroidism was related to reduced BMD, no evidence could prove a definite association between subclinical hypothyroidism and the risk of low BMD.

The Correlation of Blood Lipid Profile and its Ratio, Cystatin C and Homocysteine of Thyroid Dysfunction

This thesis aims to discuss the correlation of blood lipid and its ratio, Cystatin C(CysC) and Homocysteine (Hcy) of thyroid dysfunction patients, who are hyperthyroidism, subclinical hyperthyroidism, hypothyroidism and subclinical hypothyroidism. The authors choose each 60 patients of four groups of thyroid dysfunction and the control group to measure the serum TH, blood lipid, CysC and Hcy and calculate and analyze blood lipid ratio. As a result, on the one hand, TC, TG, LDL-C of hyperthyroidism and subclinical hyperthyroidism group are obviously lower than the control group, TC/HDL-C and TG/HDL-C, LDL-C/HDL-C, LCI and non-HDL-C of hyperthyroidism are significantly lower than the hyperthyroidism and the control group. LDL-C/HDL-C, and TC/HDL-C and TG/HDL-C of subclinical hyperthyroidism significantly reduce, and especially LCI is significant. The followings are LDL-C/HDL-C, nevertheless TC/HDL-C, TG/HDL-C are higher than the control group. On the other hand, TC, TG, LDL-C, TG/HDL-C, LDL-C/ HDL-C, LCI and non-HDL-C of hypothyroidism are prominently higher than the subclinical hypothyroidism and the control group. TC, TG and LDL-C, LDL-C/HDL-C and non-HDL-C of the subclinical hypothyroidism are higher than the control group. HDL-C is lower than the control group. TC has the highest relevance in various kinds of TH and the followings are respectively: non-HDL-C, LDL-C and LCI. CysC of hyperthyroidism and subclinical hyperthyroidism group obviously increases, whereas Hcy decreases. CysC of hypothyroidism and subclinical hypothyroidism group obviously decreases, whereas Hcy increases. According to the results, the authors come to the conclusion that the change of blood lipid ratio of subclinical thyroid dysfunction is more obvious than the index of single blood lipid and the CysC and Hcy also corresponding change. Dynamic monitoring TSH, blood lipid ratio, CysC and Hcy has an important value of transforming from subclinical thyroid dysfunction to clinical dysfunction and prediction of concurrent CVD. Joint detection is expected to become the ideal optimization combination of project.

The Fasting Serum Insulin and Glucose Levels and the Estimated Insulin Resistance in Clinical and Subclinical Hyperthyroid Patients from Saudi Arabia

Introduction: Hyperthyroidism is associated with insulin resistance, whereas its effect on pancreatic insulin secretion is controversial. The present study was aimed to investigate the influence of hyperthyroidism on the insulin availability and sensitivity and their correlations with the thyroid hormones in patients from Hail region in Saudi Arabia. Material and methods: The study was conducted on patients with thyroid disorders who were visiting the Diabetic and Endocrinology Unit of King Khalid Hospital, Hail, Saudi Arabia between April 2015 and July 2015. A total of 43 newly diagnosed hyperthyroid patients (age range: 18-77 years) were classified into: • Subclinical hyperthyroid (SHR) group: with serum TSH 25.0 pmol/L • Control (C) group of normal subjects Results: The fasting serum insulin levels in the SHR and OHR groups were severely raised by 6.22-fold and 7.67-fold, and the serum glucose by 28.76% and 54.79%, respectively compared to control, whereas, the kidney function was not altered in any of the groups. On the other hand, there were significant correlations between TSH and insulin levels (r=-0.79, P=0.0001), FT4 and insulin (r=0.34, P=0.03), TSH and insulin resistance (r =-0.5, P=0.001) and between TSH and insulin sensitivity index (r=0.90, P=0.000). Conclusion: Both clinical and subclinical hyperthyroid patients had significantly elevated fasting serum insulin and glucose levels and increased insulin resistance. Significant correlations exist between TSH and T4 with insulin levels, and between TSH with insulin resistance. The hyperthyroidism had no detrimental effects on the renal function.

Changes in Thyroid Hormone Levels Within the Normal and/or Subclinical Hyper- or Hypothyroid Range Do Not Affect Circulating Irisin Levels in Humans.

Both thyroid hormones and irisin increase energy expenditure and induce browning of adipose tissue. However, irisin physiology and regulation remain largely unknown, and existing data are mainly derived from observational studies. In this study, we aimed to elucidate whether changes in thyroid-axis hormones alter circulating irisin levels in humans, thereby exerting a direct downstream effect on serum irisin. Samples from a cross-sectional evaluation and two interventions were utilized, including patients who had previously undergone thyroidectomy. In the cross-sectional study, 96 consecutively enrolled subjects were divided into a euthyroid group and a subclinical hyperthyroid group, according to their serum thyrotropin (TSH) levels (TSH cutoff 0.3 mIU/L). In interventional study A, 34 patients who had undergone thyroidectomy due to thyroid cancer were withdrawn from their thyroxine replacement treatment for five weeks. In interventional study B, 13 patients underwent a recombinant human TSH stimulation protocol, and blood samples were drawn at baseline, day 3 (i.e., at least 24 hours after the second intramuscular injection), day 5, and day 10. Irisin concentrations were not associated with thyroid-axis hormones (i.e., TSH, free thyroxine, and free triiodiothyronine) cross-sectionally in either the overall cohort or in the euthyroid and/or subclinical hyperthyroid subgroups (p > 0.05). There was no significant difference between euthyroid and subclinical hyperthyroid subjects (p = 0.60). Levothyroxine withdrawal did not result in any changes in irisin concentrations (p = 0.33). Recombinant human TSH stimulation did not induce any significant changes in circulating irisin (p = 0.60). Changes in thyroid-axis hormone levels within the physiological or supraphysiological range do not affect circulating irisin levels in humans. Therefore, their metabolic effects are most likely independent of each other. Other regulators of irisin levels should be identified in the future.