Subclinical Primary Hypothyroidism Research Articles

Evaluating the Spectrum of Sleep Abnormalities in Patients With Primary Hypothyroidism.

This cross-sectional study included 81 participants attending the endocrinology outpatient department. The participants included those with both overt and subclinical primary hypothyroidism who were drug-naive or had a thyroid-stimulating hormone (TSH) level >4.5 µIU/L while on treatment. The study subjects were assessed based on various validated questionnaires for sleep disturbance. The study predominantly comprised 64 (79%) female participants. Overall, poor sleepers in subclinical and overt hypothyroidism were 66.7 and 60.8%. The Berlin Risk Score Questionnaire showed the occurrence of sleep apnea to be 26.7% and 27.5% in subclinical and overt groups, respectively. However, the occurrence of sleep dysfunction did not correlate with TSH values alone. Our findings demonstrate that sleep dysfunction is prevalent in patients with both overt and subclinical primary hypothyroidism. Furthermore, the severity of sleep disruption appears independent of the degree of thyroid dysfunction.

Features of post-surgical menopause with concomitant primary hypothyroidism: A prospective single-stage clinical study

Background. In recent decades, the frequency of surgical interventions on reproductive system organs has been steadily increasing. In gynecological practice, preference is given to minimally invasive surgery and precision treatments, especially involving ovaries. Despite the modern approach, it is not always possible to preserve this endocrine organ, which leads to post-surgical menopause (PSM). The relatively high incidence of total hysterectomy-associated PSM and primary hypothyroidism in late reproductive age often leads to their combination. Clinical manifestations aggravating each other form an unfavorable vicious circle. Aim. To study the features of the PSM course with concomitant primary hypothyroidism. Materials and methods. A prospective clinical study included 130 women aged 45 to 55 years with a history of PSM. The main group consisted of 70 patients with PSM with subclinical primary hypothyroidism. A control group included 60 PSM patients without thyroid disorders. We assessed the effect of hypothyroidism on the PSM course by comparing several indicators in the main and control groups. Results. It was found that in the main group patients, severe 26.5% and moderate 38.8% menopausal syndrome prevailed, while in the control group patients, such forms were twice as common. In the women of the main group, the levels of triglycerides were higher than those in the control group by 1.3 times (2.6±0.86 mmol/L and 1.43±0.33 mmol/L, respectively). The total serum alkaline phosphatase activity in patients in the study groups was 29.8% higher than in healthy women. Conclusion. It can be concluded that the severity of menopausal disorders depends on the thyroid status, with more severe in patients of the main group with hypothyroidism. In addition, in patients of the main group with hypothyroidism, dyslipidemia is more pronounced, which predisposes them to severe diseases in the future, in particular cardiovascular disorders, the unfavorable course of metabolic syndrome, and the development of postmenopausal osteoporosis.

Subclinical central hypothyroidism in patients with hypothalamic-pituitary disease: does it exist?

Central hypothyroidism (CH) is characterized by decreased thyroid hormone production due to insufficient stimulation of an otherwise normal thyroid gland by TSH. In patients with established hypothalamic-pituitary disease, a low FT4 concentration is considered highly specific, although poorly sensitive, for the diagnosis of CH. That would be comparable to diagnosing primary hypothyroidism in patients at risk only when serum FT4 concentrations are below the reference range, missing all patients with subclinical primary hypothyroidism and preventing proper therapy in patients in which thyroxine replacement is clearly beneficial. Cardiac time intervals, especially the isovolumic contraction time (ICT), have been considered the gold standard of peripheral thyroid hormone action. Using Doppler echocardiography, we have previously shown a very high proportion of prolonged ICT in patients with hypothalamic-pituitary disease and serum FT4 levels indistinguishable from controls. As ICT decreased/normalized after thyroxine-induced increases in FT4 concentrations within the normal reference range, prolonged ICT was considered a bona fide diagnostic biomarker of subclinical CH. Those findings challenge the usual interpretation that FT4 concentrations in the mid-reference range exclude hypothyroidism in patients with hypothalamic-pituitary disease. Rather, subclinical central hypothyroidism, a state analogous to subclinical primary hypothyroidism, seems to be frequent in patients with hypothalamic-pituitary disease and normal FT4 levels. They also challenge the notion that thyroid function is usually the least or the last affected in acquired hypopituitarism. The relevance of Doppler echocardiography to correctly diagnose and monitor replacement therapy in both clinical and subclinical forms of CH should improve quality of life and decrease cardiovascular risk, as already demonstrated in patients with clinical and subclinical primary hypothyroidism.

Structural and Functional Alterations of Hippocampal Subfields in Patients With Adult-Onset Primary Hypothyroidism.

Hypothyroidism is often associated with cognitive and emotional dysregulation; however, the underlying neuropathological mechanisms remain elusive. The study aimed to characterize abnormal alterations in hippocampal subfield volumes and functional connectivity (FC) in patients with subclinical hypothyroidism (SCH) and overt hypothyroidism (OH). This cross-sectional observational study comprised 47 and 40 patients with newly diagnosed adult-onset primary SCH and OH, respectively, and 53 well-matched healthy controls (HCs). The demographics, clinical variables, and neuropsychological scale scores were collected. Next, the hippocampal subfield volumes and seed-based FC were compared between the groups. Finally, correlation analyses were performed. SCH and OH exhibited significant alterations in cognitive and emotional scale scores. Specifically, the volumes of the right granule cell molecular layer of the dentate gyrus (GC-ML-DG) head, cornu ammonis (CA) 4, and CA3 head were reduced in the SCH and OH groups. Moreover, the volumes of the right molecular layer head, CA1 body, left GC-ML-DG head, and CA4 head were lower in SCH. In addition, the hippocampal subfield volumes decreased more significantly in SCH than OH. The seed-based FC decreased in SCH but increased in OH compared with HCs. Correlation analyses revealed thyroid hormone was negatively correlated with FC values in hypothyroidism. Patients with SCH and OH might be at risk of cognitive decline, anxiety, or depression, and exhibited alterations in volume and FC in specific hippocampal subfields. Furthermore, the reduction in volume was more pronounced in SCH. This study provides novel insights into the neuropathological mechanisms of brain impairment in hypothyroidism.

Risk factors of early thyroid dysfunction after definitive radiotherapy in nasopharyngeal carcinoma patients.

To explore the patterns and risk factors of early thyroid dysfunction in nasopharyngeal carcinoma (NPC) patients within 1 year after intensity-modulated radiation therapy (IMRT). Patients with NPC who received definitive IMRT between April 2016 and April 2020 were included. All patients had normal thyroid function before definitive IMRT. The chi-square test, Student's T-test, Mann-Whitney U test, Kaplan-Meier method, receiver operating characteristics curve, and Cox proportional hazard analysis were used for statistical analysis. A total of 132 NPC patients were identified. Of these patients, 56 (42.4%) had hypothyroidism and 17 (12.9%) had hyperthyroidism. The median time to hypothyroidism and hyperthyroidism was 9 months (range, 1-12 months) and 1 month (range, 1-6 months) after definitive IMRT, respectively. In patients with hypothyroidism, 41 (73.2%) had subclinical hypothyroidism and 15 (26.8%) had clinical hypothyroidism. In those with hyperthyroidism, 12 patients (70.6%) had subclinical hyperthyroidism, and five patients (29.4%) had clinical hyperthyroidism. Age, clinical stage, thyroid volume, and V45 were independent risk factors for early radiation-induced hypothyroidism within 1 year after IMRT. Patients aged <47 years, stage III/IV disease, or pre-irradiation thyroid volume < 14 cm3 had higher risks of developing hypothyroidism. Primary subclinical hypothyroidism was the most common subtype of early thyroid dysfunction in NPC patients within 1 year after IMRT. Age, clinical stage, thyroid volume, and V45 were independent risk factors for early radiation-induced hypothyroidism in NPC patients.

Cardiac arrhythmias associated with subclinical primary hypothyroidism: about two cases

Cardiac arrhythmias associated with subclinical primary hypothyroidism: about two cases

Vitamin B12 (Cobalamin) Deficiency in Overt and Subclinical Primary Hypothyroidism.

Background:B12 (cobalamin) deficiency has been reported in hypothyroid patients with variable prevalence rates thus routine screening of hypothyroid patients was recommended by some and discouraged by others. We aimed to assess the prevalence of B12 deficiency among hypothyroid patients and to evaluate for pernicious anemia and celiac disease as etiologies.Methods:A total 133 patients were included. Thyroid hormones and thyroid peroxidase (TPO) autoantibodies were measured. Serum B12 was measured and if deficient, intrinsic factor antibodies (IFAB) and tissue transglutaminase (tTG) antibodies were evaluated.Results:Our study included 45 patients with overt hypothyroidism (OH), 48 patients with subclinical hypothyroidism (SCH), and 40 patients as controls. Mean age was 34.3 years and 82% were females. TPO antibodies were positive in 73.5% of OH and 51.1% of SCH patients. B12 deficiency was detected in 33.3%, 47.9%, and 37.5% of OH, SCH, and controls, respectively with no significant difference (P = .334). Borderline-to-low B12 level was more prevalent in the OH and the SCH groups compared to controls (68.9%, 85.4%, and 57.5%, respectively; P = .014). Among B12-deficient hypothyroid patients, 7.5% had positive IFAB and 13.3% had positive tTG antibodies. We did not find a significant association of TPO positivity and B12 deficiency (OR, 0.69; 95% CI 0.3-1.57; P = .147).Conclusion:We did not find a higher prevalence of B12 deficiency among hypothyroid patients nor an association with TPO positivity. Borderline B12 levels were more prevalent among hypothyroid patients.

Association of thyroid stimulating hormone and iron profile among patients with subclinical primary hypothyroidism

Introduction: Physiologically, thyroid hormones have a vital role in maintaining metabolic balance of the human body. Subclinical hypothyroidism is often associated with hematological disorders including iron-deficiency anemia. This study aims to correlate thyroid stimulating hormone and iron profile in patients with subclinical primary hypothyroidism. Materials and methods: This is a cross-sectional study conducted in Nepal Medical College and Teaching Hospital, Kathmandu, Nepal among patients with subclinical primary hypothyroidism. The study was conducted from October 2018 to December 2019. Total of 60 patients above the age of 18 years were enrolled for the study. Thyroid function test was done by automated machine using electro chemiluminescent immunoassay technique and iron profile test was done by Immunoassay method using Vitros Analyzer. Pearson’s correlation test was applied to find the correlation between thyroid stimulating hormone and iron profile. Results: Among the 60 participants with subclinical hypothyroidism 23% were males and 77% were females with a mean age of 43 years. The mean serum iron (male =81.14 μg/dl female = 69.5 μg/dl), mean total iron binding capacity (male =470.35 μg/dl, female = 477.94 μg/ dl) and mean ferritin level (male=91.15 μg/dl, female=95.51 μg/dl) were within reference value of our laboratory. A negative correlation was observed between thyroid stimulating hormone levels and serum iron (r=0.376, P=0.003), thyroid stimulating hormone and total iron binding capacity also showed a negative correlation (r=-0.083, P=0.27). Similarly thyroid stimulating hormone and transferrin saturation also showed a negative correlation (r=-0.098, P=0.455) whereas, a positive correlation was observed between thyroid stimulating hormone and ferritin (r=0.037, P=0.779). Conclusions: This study concludes that thyroid stimulating hormone is negatively associated to serum iron, total iron binding capacity and transferrin saturation whereas, positively associated with ferritin among patients with subclinical hypothyroidism.

ASSOCIATION OF THYROID STATUS IN PATIENTS WITH CHRONIC KIDNEY DISEASE IN A TERTIARY CARE HOSPITAL

INTRODUCTION: The concept of subclinical primary hypothyroidism has emerged over the past several decades, as our ability to detect subtle changes in thyroid function tests is progressively improved. Although it is recognized that patients with subclinical primary hypothyroidism may have subtle symptoms of thyroid dysfunction, the denition is purely a biochemical one, dened as elevated serum thyrotropin (TSH) levels but 1 normal free thyroxine (FT4) levels. AIMS AND OBJECTIVES: Proposed topic of research: Prevalence of Subclinical Hypothyroidism In Patients With Chronic Kidney Disease, Objective of Proposed Research: Prevalence of Subclinical Hypothyroidism In Patients With Chronic Kidney Disease, Broad objectives: To estimate TSH and Free T4 levels in Chronic Kidney Disease patients and calculate the eGFR using MDRD formula and classify the patients with CKD into 5 stages METHODOLOGY: This Cross sectional Observational Study was single-centre study, which was take place at NRS Hospital Kolkata total time take April 2017 to March 2018. RESULT AND ANALYSIS: We found 10(10.0%) patients had overt hypothyroidsm. 100(100.0%) patients had &gt;3 month of illness. The mean TSH (mean± s.d.) of patients was 6.5200 ± 4.4210 micro IU/mL. The mean FT4 (mean± s.d.) of patients was 1.0509 ± .3960 ng/dL. The mean urea (mean± s.d.) of patients was 96.8830 ± 31.6749. The mean creatinine (mean± s.d.) of patients was 3.3010 ± 1.2648. The mean eGFR (MDRD) (mean± s.d.) of patients was 24.5080 ± 16.6236 ml/min /1#73m2. Association of age in years vs. subclinical hypothirodism was not statistically signicant (p=0.1486). CONCLUSION: We conclude that the prevalence of subclinical hypothyroidism is high among all the stages of CKD patients. Need for treatment depends on the patient's clinical scenario and decision of the clinician based on the presentation. There is an increasing trend of decreased thyroid functional status along with decrease of estimated GFR (eGFR). Chronic kidney disease impairs thyroid functional status in different ways. Thyroid functional status evaluation is recommended in each and every patient of CKD.

Эффективность комплексного метода лечения больных глаукомой с первичным субклиническим гипотиреозом

Актуальность. Взаимосвязь первичной открытоугольной глаукомы (ПОУГ) с гипотиреозом в настоящее время является актуальным вопросом офтальмологической практики. Цель: изучить эффективность комплексного метода лечения больных ПОУГ с первичным субклиничес­ким гипотиреозом. Материалы и методы. Под наблюдением находились 90 больных (90 глаз). I группу наблюдения (группу контроля) составили 50 пациентов (50 глаз) с ПОУГ без эндокринной патологии, II группу наблюдения — 40 пациентов (40 глаз) с ПОУГ в сочетании с первичным гипотиреозом, у которых применялся патогенетически ориентированный метод лечения, который заключался в комплексном применении гормонстабилизирующих препаратов (левотироксина) с общепринятой медикаментозной терапией ПОУГ. У всех пациентов также был проведен анализ функциональных и клинических показателей органа зрения, а именно остроты зрения, внутриглазного давления (ВГД), периметрических показателей MD и PSD, показателей ОКТ Area cup/disc ratio, Agv. RNFL и Vrim в ближайшие и отдаленные сроки наблюдения. Результаты. При обследовании пациентов II группы через 3 года было установлено, что у больных ПОУГ с первичным гипотиреозом, которым проводили лечение с помощью комплексного метода, показатель остроты зрения составил 0,86 ± 0,12, ВГД — 25,80 ± 5,22 мм рт.ст., MD — –8,10 ± 9,14 dB, PSD — 3,74 ± 3,30, показатель Area cup/disc ratio — 0,60 ± 3,32, RNFL — 84,3 ± 9,7 мкм, Vrim — 0,14 ± 0,06 мм3. Выводы. Применение комплексного метода лечения ПОУГ с первичным субклиническим гипотиреозом позволило статистически значимо (р &lt; 0,05) повысить остроту зрения — на 10 %, снизить ВГД на 4 % через 1,5 года, повысить остроту зрения на 14 %, снизить ВГД на 4 % через 2 года, повысить остроту зрения на 17 %, снизить ВГД на 5 % через 2,5 года, повысить остроту зрения на 18 %, снизить ВГД на 5 % через 3 года; повысить MD на 85 %, снизить PSD на 43 % через 2 года, повысить MD на 110 %, снизить PSD на 60 % через 2,5 года; повысить MD на 115 % через 3 года по сравнению с больными ПОУГ без эндокринной патологии, повысить MD на 115 %, снизить PSD на 73 % через 3 года; снизить Area cup/disc ratio на 20 %, повысить RNFL на 9 % и Vrim на 40 % через 2,5 года, через 3 года снизить Area cup/disc ratio на 30 %, повысить RNFL на 10 % и Vrim на 56 % по сравнению с больными ПОУГ без эндокринной патологии.

Electrocardiographic changes in subclinical hypothyroidism

Background: Subclinical hypothyroidism (SCH) is an apparently asymptomatic condition defined by increased serum thyrotropin (thyroid-stimulating hormone) concentrations, but normal serum free T3 and free T4 hormone levels. Thyroid hormones are known to affect the heart and vasculature. The effect of SCH on cardiovascular system is not much studied. Aims and Objectives: The objectives of this study were to study the electrocardiogram (ECG) changes in a group of newly diagnosed subclinical hypothyroid females and to compare the ECG changes in subclinical hypothyroid females with normal healthy euthyroid individuals. Materials and Methods: We studied 30 non-pregnant females with primary SCH in the age group of 20–40 years, who were newly diagnosed and untreated. Thirty age- and body mass index-matched healthy individuals were taken as controls. Clinical and biochemical parameters and ECG were studied. Statistical software, “GraphPad QuickCalcs,” was used for the statistical analysis. Results: Mean QTc interval of the study group was significantly longer than those of the control group (P = 0.037). Other parameters of ECG were comparable in both the groups. Conclusion: ECG changes in SCH showed increase in the QTc interval as compared to controls, which predisposes to the potentially life-threatening ventricular arrhythmias. However, the other parameters of ECG such as QRS interval, PR interval, and QRS axis were similar to the controls.

POEMS syndrome: a rare cause of adrenal insufficiency in a young male.

POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein and Skin changes) is a rare multisystemic disease. Clinical presentation is variable, the only mandatory criteria being polyneuropathy and monoclonal gammapathy in association with one major and one minor criterion. Primary adrenal insufficiency is rarely reported. We describe a case of a 33-year-old patient, in whom the presenting symptoms were mandibular mass, chronic sensory-motor peripheral polyneuropathy and adrenal insufficiency. The laboratory evaluation revealed thrombocytosis, severe hyperkalemia with normal renal function, normal protein electrophoresis and negative serum immunofixation for monoclonal protein. Endocrinologic laboratory work-up confirmed Addison's disease and revealed subclinical primary hypothyroidism. Thoracic abdominal CT showed hepatosplenomegaly, multiple sclerotic lesions in thoracic vertebra and ribs. The histopathologic examination of the mandibular mass was nondiagnostic. Bone marrow biopsy revealed plasma cell dyscrasia and confirmed POEMS syndrome. Axillary lymphadenopathy biopsy: Castleman's disease. Gluco-mineralocorticoid substitution and levothyroxine therapy were started with clinical improvement. Autologous hematopoietic cell transplantation (HCT) was planned, cyclophosphamide induction was started. Meanwhile the patient suffered two ischemic strokes which resulted in aphasia and hemiparesis. Cerebral angiography revealed vascular lesions compatible with vasculitis and stenosis of two cerebral arteries. The patient deceased 14 months after the diagnosis. The young age at presentation, multiplicity of manifestations and difficulties in investigation along with the absence of serum monoclonal protein made the diagnosis challenging. We report this case to highlight the need to consider POEMS syndrome in differential diagnosis of peripheral neuropathy in association with endocrine abnormalities even in young patients. POEMS syndrome is considered a 'low tumor burden disease' and the monoclonal protein in 15% of cases is not found by immunofixation. Neuropathy is the dominant characteristic of POEMS syndrome and it is peripheral, ascending, symmetric and affecting both sensation and motor function. Endocrinopathies are a frequent feature of POEMS syndrome, but the cause is unknown. The most common endocrinopathies are hypogonadism, primary hypothyroidism and abnormalities in glucose metabolism. There is no standard therapy; however, patients with disseminated bone marrow involvement are treated with chemotherapy with or without HCT.

Thyroid Disorders in Homozygous β-Thalassemia: Current Knowledge, Emerging Issues and Open Problems.

Changes in thyroid function and thyroid function tests occur in patients with β-thalassemia major (TM). The frequency of hypothyroidism in TM patients ranges from 4% to 29 % in different reports. The wide variation has been attributed to several factors such as patients’ genotype, age, ethnic heterogeneity, treatment protocols of transfusions and chelation, and varying compliance to treatment. Hypothyroidism is the result of primary gland failure or insufficient thyroid gland stimulation by the hypothalamus or pituitary gland. The main laboratory parameters of thyroid function are the assessments of serum thyroid-stimulating hor-mone (TSH) and serum free thyroxine (FT4). It is of primary importance to interpret these measurements within the context of the laboratory-specific normative range for each test. An elevated serum TSH level with a standard range of serum FT4 level is consistent with subclinical hypothyroidism. A low serum FT4 level with a low, or inappropriately normal, serum TSH level is consistent with secondary hypothyroidism. Doctors caring for TM patients most commonly encounter subjects with subclinical primary hypothyroidism in the second decade of life. Several aspects remain to be elucidated as the frequency of thyroid cancer and the possible existence of a relationship between thyroid dysfunction, on one hand, cardiovascular diseases, components of metabolic syndrome (insulin resistance) and hypercoagulable state, on the other hand. Further studies are needed to explain these emerging issues. Following a brief description of thyroid hormone regulation, production and actions, this article is conceptually divided into two parts; the first reports the spectrum of thyroid disease occurring in patients with TM, and the second part focuses on the emerging issues and the open problems in TM patients with thyroid disorders.

Features of carbohydrate metabolism in a patient with type 1 diabetes mellitus in subclinical hypothyroidism in the outcome of chronic autoimmune thyroiditis

Diabetes mellitus and primary hypothyroidism, in the outcome of chronic autoimmune thyroiditis, the two most common diseases in endocrinology and the practicing doctor are important not to forget about the possible association of these pathologies. This applies to patients with diabetes mellitus, both 1 and 2 types. However, the combination of these two pathologies is more common in type 1 diabetes, which is due to the autoimmune nature of these diseases. A clinical case of a patient with type 1 diabetes mellitus, which is on pump insulin therapy, is presented, which, in the background of previously selected therapy, during the last 2 months, episodes of hypoglycemia increased. In the course of the survey, primary subclinical hypothyroidism was identified, in the outcome of chronic autoimmune thyroiditis. Against the background of the achievement of euthyroidism, it was possible to achieve compensation of carbohydrate metabolism without correction of previously selected insulin therapy. The high incidence of thyroid dysfunction in patients with diabetes mellitus, and as a consequence, the deterioration in the compensation of carbohydrate metabolism, requires a systematic screening of thyroid disorders in the presence of diabetes mellitus.

Показатели глобальной продольной деформации миокарда левого желудочка и коронарного кровотока у пациентов с первичным гипотиреозом

Assessment of global longitudinal strain of left ventricle and coronary bloodflow in patients with primary subclinical hypothyroidism. The study involved 23 women with primary subclinical hypothyroidism of age from 55 to 75 years. Physical examination, transthoracic EchoCG, coronary bloodflow assessment and global LV longitudinal strain by speckle tracking method were performed to all patients. The data obtained were compared to the results of 20 women without any thyroid diseases comparable to the main group by age and concomitant diseases. Patients with primary subclinical hypothyroidism have signs of diastolic dysfunction significantly more frequently than in control group, and increased values of posterior left ventricle wall and interventricular septum thickness. Global longitudinal strain of left ventricle in patients with hypothyroidism was lower than in control group and patients with hypothyroidism had higher FVI values in perforant coronary arteries. Patients with subclinical hypothyroidism demonstrated decrease of global longitudinal strain and increase of volume bloddflow rate in performant coronary arteries.

A study of prevalence and pattern of anemia in primary hypothyroidism

Background: Anemia is a common disorder affecting Indian population which may be further influenced by hypothyroidism. Hematopoietic system is one of the primary systems affected by hypothyroidism and anemia could be its first manifestation. Numerous mechanisms are involved in the pathogenesis of this anemia that can be microcytic, macrocytic, and normocytic. We designed this study to investigate the incidence of anemia its morphological pattern in hypothyroidism patients. Objectives: The objectives were to investigate the incidence of anemia and its morphological pattern in patients with overt and subclinical hypothyroidism. Materials and Methods: A prospective observational study was conducted in patients presenting with overt or subclinical primary hypothyroidism in King George Medical University from August 2016 to September 2017. Patients with age >18 years and newly diagnosed cases of subclinical hypothyroidism were included. Patients with secondary causes for anemia or patients under treatment with drugs that might affect blood parameters were excluded. Results: In our present study, female predominance was 82% with more common age group between 31 and 40 years. The incidence of anemia was found to be 69% in the overt hypothyroid group and 56% in the subclinical hypothyroid group. Normocytic normochromic (53%) was the most common type of anemia, followed by microcytic (30%) and macrocytic anemia (27%). Serum iron levels were significantly low in both overt and subclinical hypothyroid groups. Serum anti-thyroid peroxidase (TPO) positivity was 65.53%. Anemia was severe in cases with high thyroid-stimulating hormone (TSH). Conclusion: Normocytic normochromic anemia is the most common type of anemia in hypothyroid patients. The incidence of anemia was found to be 69% in the overt hypothyroid group and 56% in the subclinical hypothyroid group. Presence of anemia in subclinical hypothyroidism was almost as high as in patients with overt hypothyroidism. TPO antibodies were linked with higher likelihood of developing anemia in hypothyroidism. Higher TSH values were associated with more severe anemia.

Prevalence of Subclinical Hypothyroidism in Patients with Chronic Kidney Disease

Background: Subclinical primary hypothyroidism is highly prevalent in the general population, especially in the elderly and females above 45yrs of age. However, the prevalence of subclinical primary hypothyroidism in persons with chronic kidney disease (CKD) not requiring dialysis is not well defined. Aim: 1. To Study the prevalence of Subclinical Hypothyroidism in patients with CKD, and 2. To study the correlation between thyroid dysfunction and the various stages of CKD. Materials and methods: This study was conducted in Stanley Medical College, Chennai, Tamil Nadu, India by the Department of Nephrology and Biochemistry in May 2016. Cross-sectional data from 50 healthy adult outpatients, who were consecutively referred for master health check-up considered as controls and 50 nondialytic CKD patients satisfying the study criteria considered as cases, were analyzed. Glomerular filtration rate (GFR) was estimated by the abbreviated Modification of Diet in Renal Disease equation. Pearson correlation coefficient was used to evaluate the degree of association between prevalent subclinical primary hypothyroidism and estimated GFR. Students unpaired t test was used to compare the means between two groups. Results: Among 50 cases, 30 (60 %) had subclinical primary hypothyroidism. The prevalence of subclinical primary hypothyroidism increased from 2% at an estimated GFR >90 ml/min per 1.73 m2 (controls) to 60% at an estimated GFR < 90 ml/min per 1.73 m2 (P < 0.001 for trend). The prevalence of subclinical primary hypothyroidism increased from 59% at an estimated GFR between 15 & 89 ml/min per 1.73 m2 to 90% at an estimated GFR < 15 ml/min per 1.73 m2. Conclusions: These findings suggest that subclinical primary hypothyroidism is a relatively common condition (60%) among persons with CKD not requiring dialysis, and it is independently associated with progressively lower estimated GFR in a small group of patients.

Resistance to thyrotropin: familial case report

Two female dizygotic twins with subclinical primary hypothyroidism due to homozygous p.R450H mutation in TSHR gene are presented. A 5-year follow-up in both cases showed no progression of thyroid dysfunction. Indications for levothyroxine replacement in subclinical hypothyroidism are discussed.

Effect of metformin on serum thyrotropin level in type 2 diabetic patients with subclinical hypothyroidism

Objective To examine the effect of metformin on serum thyrotropin (TSH) level in diabetic patients with subclinical hypothyroidism (SCH).Methods The long-term effects of metformin on thyroid axis hormones were assessed in 55 diabetic patients with primary SCH who were untreated with L-T4(study group),as well as in 31 diabetic patients with normal thyroid function (control group).According to using metformin or not,patients of study group were divided into the metformin group (group 1,n =28),and the non-metformin group(group 2,n =27).Serum TSH levels were compared between baseline and follow-up in patients receiving metformin treatment.Results After 30 weeks of metformin administration,a significant TSH decrease(t =2.91,P ＜ 0.05) was observed in group 1 [from(6.98 ± 1.92) to(2.44 ± 0.61) mIU/L].After stopping metformin therapy,the level of TSH at 52 weeks fol low-up was back to the baseline level [(6.99 ± 1.76) mIU/L,P ＞ 0.05].There was no significant difference in TSH level between baseline and after 30 weeks follow-up in group 2[(6.01 ± 1.63) mIU/L vs(6.21 ± 1.71) mIU/L,P ＞0.05].At the end of 30 weeks follow-up,no significant differences were found in body mass index and thyroid func tion in both metformin group and non-metformin group.In control group,metformin administration for 30 weeks had no effect on TSH level(P ＞ 0.05).Conclusion Metformin administration influences TSH without change of FT4 level in type 2 diabetic patients with primary SCH. Key words: Metformin; Subclinical hypothyroidism; Diabetes mellitus, type 2 ; Thyrotropin

Schilddrüsenhormontherapie – Erwiderung

The autoimmune thyroiditis with overt or subclinical primary hypothyroidism is the most common endocrine disease. Although the diagnosis of hypothyroidism is not difficult, the question when a replacement therapy in subclinical hypothyroidism should be initiated is still under discussion. In patients with overt hypothyroidism defined as low FT4 and elevated TSH or TSH > 10 mU/L a replacement with levothyroxine is clearly indicated. In patients with subclinical hypothyroidism defined as a TSH between 4 and 10 mU/L and normal FT4, the treatment with Levothyroxine depends on the underlying disease and symptoms. Levothyroxine is a prohormone with is activated by deiodination in the organs to triiodothyronine. Therefore, levothyroxine for replacement therapy is mainly used. Some patients, however, do not feel well with this treatment and therefore studies with a combination therapy of levothyroxine and triiodothyronine had been performed and it could be shown that this might be related to a polymorphism in type 2 deiodinase in some patients, with the consequence of lower intracellular triodothyronine formation. In women on levothyroxine replacement therapy getting pregnant, the demand of levothyroxine increases up to 25-50 µg, especially in the early weeks of pregnancy. It also has to be considered that the resorption of levothyroxine depends on normal stomach acid and therefore patients on acid blockers or atrophic gastritis require higher dosages of levothyroxine. Only patients after thyroidectomy because of differentiated thyroid carcinoma with higher grad of malignancy need a TSH suppressive therapy, those with occult papillary thyroid carcinoma the TSH should be within the low normal range.