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Prevalence of hypothyroidism in Assam: A clinic-based observational study

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  • AIIMS Guwahati
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... A total of 625 participants took part in the study. The characteristics of all participants are shown in Table- 16.41 BMI -body mass index (wt in kg /ht in met sq.); WHR -waist-to-hip ratio; WHtR -waist-to-ht ratio; SBP, DBP -systolic , diastolic blood pressure; FBG -fasting blood glucose; TG -Triglycerides; Chol -total cholesterol; HDL -high-density lipoproteins; LDL -low-density lipoproteins; TSH -thyroid stimulating hormone (thyrotrophin); FT4 -free tetra-iodothyronin. ...
... Jeannine et al. reported that the prevalence of hypothyroidism varied 3% to 11% depending on the diagnostic cut-off of TSH, geographical site and ethnicity [15]. A clinic based study in Assam reported the prevalence as 13.1% [16]. Most of the studies opined that the prevalence among women is higher than that of men [2,3,16,17]. ...
... A clinic based study in Assam reported the prevalence as 13.1% [16]. Most of the studies opined that the prevalence among women is higher than that of men [2,3,16,17]. We also found higher prevalence in women than men (8.2% vs. 4.1%, p = 0.09), but the difference was not significant. ...
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Background and aims: Hypothyroidism is a common global endocrine disorder. The magnitude of hypothyroidism at community level in Bangladesh is unknown except some clinic-based studies. The present study was undertaken to determine the prevalence of hypothyroidism in different occupational groups of Bangladeshi population and to assess the risks related to it. Study design: Three occupational groups (house-wives, college students, rickshaw-pullers) of native Bangladeshi population were purposively selected. Investigations included socio-demography, anthropometry, blood pressure and biochemistry [fasting blood glucose, lipids, thyroid stimulating hormone (TSH) and free thyroxin (FT4)]. Laboratory tests were done only on a randomized sample of participants. Results: Overall, 626 (M/F=123 / 503) participants with a mean age of 35.9 (34.75 – 37.02) years volunteered. The mean values of all participant for TSH and FT4 were 2.08 (95%CI: 1.72 – 2.45) μiu/ml and 13.04 (95CI:12.86 – 13.22) pmol/L respectively. The third percentile of TSH ranged from 0.42 to 0.46 μiu/ml and 97th percentile ranged from 5.16 to 5.24 μiu/ml. For FT4, the 3rd and the 97th percentile were 10.3 and 16.41 pmol/L, respectively. The prevalence of hypothyroidism in both sexes was 7.0% (M/F=4.1/8.3%). Occupational groups, sex and increasing age, obesity, blood pressure, and lipids showed no association with hypothyroidism. Hyperglycemia was proved to be a significant risk for hypothyroidism (prevalence in diabetic vs. non-diabetic was12.9% vs. 5.5%, p = 0.04; FBG was correlated with TSH, r = 0.138, p
... A total of 366 of 1484 (prevalence 24%) participants received a diagnosis of hypothyroidism, which is similar to the findings of a study by Mahanta et al. from Assam Medical College [12] in 2017 (prevalence 24%). Out of 366 participants, 311 were women and 55 were men. ...
... Hence, this figure may be higher than the actual prevalence in the general population. However, the high prevalence of 24% (Figure 2) in the current study is similar to the study results of Mahanta et al. from Assam Medical College [12] in 2017. ...
Article
Background Hypothyroidism is a common endocrine disorder worldwide. Studies on the prevalence of hypothyroidism in different geographical territories of India are sparse. Data on the prevalence of hypothyroidism in India's coal mine areas are lacking. Therefore, we conducted a cross-sectional study to determine the prevalence of hypothyroidism in the adult population living in the coal mine areas of West Bokaro, Jharkhand, India. Methods In total, 1484 individuals of both sexes attending the outpatient department (OPD) of Tata Central Hospital, West Bokaro, Jharkhand, with varied symptoms were screened for thyroid-stimulating hormone (TSH) levels from January 2021 to February 2022. The age of the study participants ranged from 15 to 80 years. Results In total, 366 participants had hypothyroidism (subclinical as well as overt). The prevalence of hypothyroidism was greater in women than in men. Among the 366 patients with hypothyroidism, 311 were women and 55 were men, and the ratio was 5.5:1. The percentage of the population having hypothyroidism was 24% in this study, which is higher than that reported in other parts of India; however, our results are similar to those of a study conducted in Assam in 2017. Among patients with high TSH levels, 47%, 25%, and 19% had TSH in the range of 5.6-7.5, 7.6-10.6, and 10.6-20 μU/mL, respectively. Conclusions Subclinical and overt hypothyroidism are common in eastern India. Patients with undiagnosed fatigue and weight gain must be screened for TSH levels. Hypothyroidism is no longer a rarity, and coal mine areas are no exception to this phenomenon. A population‑based epidemiological study of thyroid disorders in coal mine areas is an urgent need.
... On one hand, part of the country is yet to become iodine sufficient, whereas on the other hand, the emergence of SCH has emerged as a new endemic. Although clinic-based study reports are available, [15] it is essential to penetrate newer population and newer geographic areas of the country which have hitherto remain uncovered in such epidemiological surveys to comprehend the nature of thyroid disorders and their associations with thyroid autoimmunity and other common comorbidities. Such understandings underscore the rationale behind the execution of a study like ours. ...
... The prevalence rate of goiter by manual palpation was 10.05% and was almost in line with previous study data reporting 13% prevalence in a clinic-based study from Guwahati and 12% prevalence found in a recent Indian population-based study. [15,25] The prevalence of thyrotoxicosis in India was around 2% in a nationwide epidemiological study, including both subclinical and overt cases. [9] However, in our study, only two individuals, both females, qualified for a diagnosis of subclinical thyrotoxicosis (0.01% prevalence), which may either be a geographical variation or due to changing pattern of thyroid epidemiology. ...
... In recent years, thyroidism is unknowingly emerging as a major public health problem in India and it produces an enormous burden on the economy of the country due to high prevalence, risk of progression to overt hypothyroidism and it can lead to adverse cardiovascular consequences [10]. ...
Article
Background: Hypothyroidism is a common endocrine disorder resulting from deciency of thyroid hormone. Hyperthyroidism is a set of disorders that involve excess synthesis and secretion of thyroid hormone by the thyroid gland. Ghrelin is octanoylated peptide containing a 28 amino acid act as an energy balance regulator & play an important role in metabolic process .The aim of the study was to establish possible relationship between them. Materials and methods: The present study is a cross sectional study, was conducted in the Department of Biochemistry, J.L.N. Medical college and associated group of Hospitals, Ajmer (Raj.). 65 hypothyroid subjects (group-II) and 65 hyperthyroid subjects (group-III) attending Medical OPD of J.L.N. Hospitals were included and 130 age-sex matched euthyroid controls (group-I) were selected. Results: In hypothyroid subjects, mean serum Ghrelin levels were found to be signicantly higher in comparison to healthy subjects (p<0.0001). In hyperthyroid subjects, mean serum Ghrelin levels were found to be signicantly lower in comparison to healthy subjects (p<0.0001). Conclusion: The overall ndings of the present study thus conrm that serum Ghrelin level is signicantly higher in Hypothyroid subjects and the level is signicantly lower in the Hyperthyroid subjects, thus we have found positive association between serum TSH level and Ghrelin level. However, further experimental and observational studies are needed to illustrate the role of Ghrelin in Hypothyroidism and Hyperthyroidism.
... It's mostly caused by autoimmunity or dietary iodine deficiency [1,2]. The prevalence of hypothyroidism is affected by many factors such as age, gender, and geographical area of the population [3]. The clinical manifestations of hypothyroidism include dry skin, cold intolerance, increased body weight, constipation, hair loss, dyspnea, hoarseness of voice, coarse puffy appearance, fatigue, bradycardia, diastolic hypertension, goiter, hypothermia, and menstrual disturbance in female [4][5][6]. ...
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Objectives: Hypothyroidism adversely affects pulmonary function, which may improve by thyroxine therapy. Limited studies about the effect of hypothyroidism on spirometric parameters in adult patients were conducted in Basra, south of Iraq. Moreover, the effect of thyroxine therapy on spirometric parameters was not covered by these studies. In this study, pulmonary function in adult’s hypothyroid patients was evaluated by spirometry to detect any impairment, type of impairment, and to evaluate the effect of thyroxine therapy. Methods: A comparative study was conducted in Al-Faiha Specialized Diabetes, Endocrine, and Metabolism Center (FDEMC) in Al-Faiha teaching hospital, Basrah, Iraq. Subjects are divided into four groups: uncontrolled hypothyroid group (n=72), controlled hypothyroid group (n=60), newly diagnosed hypothyroid group (n=52), and control group (n=110). Spirometry was done to all subjects in sitting position, it’s repeated at least three times and the best result was recorded. Results: A significantly (p<0.05) less spirometric parameters and more abnormal pulmonary function test (PFT) were noticed in hypothyroid groups, the reduction were more pronounced in the uncontrolled hypothyroid group. The abnormality in PFT was mostly of restrictive type. A significantly (p<0.05) negative correlation has been found between thyroid-stimulating hormone (TSH) and spirometric parameters, while the correlation of fT4 is significantly (p<0.05) positive with FVC% and FEV%
... They concluded that high prevalence of overt hypothyroidism is probably due to referral bias to this clinic-based registry study; hence, this figure may be higher than the actual prevalence in the general population. [9] Though we cannot counter the referral bias in our study, but our observation was mostly in community clinics who came voluntarily or by spread of mouth awareness. The higher prevalence in our study cannot be entirely credited to referral bias. ...
Article
Introduction: Higher prevalence of thyroid diseases are noted with increasing age. Symptoms of thyroid disorders often develop so insidiously, that they go unnoticed and there is also the risk of being misinterpreted for menopausal symptoms. Present study was executed in view of paucity of data regarding thyroid disorders among tribal perimenopausal age group and there was a need for timely intervention of this chronic noncommunicable disorder among these women. Aim: To determine the thyroid function and anti-Thyroid Peroxidase Antibody (anti-TPO Ab) status among the tribal perimenopausal women. Materials and Methods: A descriptive, cross-sectional study was conducted for a period of six months from July 2017 to December 2017 among perimenopausal women in the age group of 40-55 years residing at Hakki Pikki Tribal Colony near Bengaluru, Karnataka, India. Thyroid Stimulating Hormone (TSH), Total T3 (Total Tri iodothyronine), Total T4 (Total Tetraidiodothyronine) and anti-TPO antibody levels were estimated by Chemiluminescence Immuno Assay (CLIA). Data was analysed using Open Epi software to find out Mean±SD, p-value (Student’s t-test with significance set at p30 IU/mL) was found in 14 (34.14%) women amongst 41 perimenopausal subjects. Raised anti-TPO Ab was observed in all the 3 (100%) SCH women and 11 (26.82%) euthyroid women. Significant difference (p
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Hypothyroidism is believed to be a common health issue in India, as it is worldwide. However, there is a paucity of data on the prevalence of hypothyroidism in adult population of India. A cross-sectional, multi-centre, epidemiological study was conducted in eight major cities (Bangalore, Chennai, Delhi, Goa, Mumbai, Hyderabad, Ahmedabad and Kolkata) of India to study the prevalence of hypothyroidism among adult population. Thyroid abnormalities were diagnosed on the basis of laboratory results (serum FT3, FT4 and Thyroid Stimulating Hormone [TSH]). Patients with history of hypothyroidism and receiving levothyroxine therapy or those with serum free T4 <0.89 ng/dl and TSH >5.50 μU/ml, were categorized as hypothyroid. The prevalence of self reported and undetected hypothyroidism, and anti-thyroid peroxidase (anti-TPO) antibody positivity was assessed. A total of 5376 adult male or non-pregnant female participants ≥18 years of age were enrolled, of which 5360 (mean age: 46 ± 14.68 years; 53.70% females) were evaluated. The overall prevalence of hypothyroidism was 10.95% (n = 587, 95% CI, 10.11-11.78) of which 7.48% (n = 401) patients self reported the condition, whereas 3.47% (n = 186) were previously undetected. Inland cities showed a higher prevalence of hypothyroidism as compared to coastal cities. A significantly higher (P < 0.05) proportion of females vs. males (15.86% vs 5.02%) and older vs. younger (13.11% vs 7.53%), adults were diagnosed with hypothyroidism. Additionally, 8.02% (n = 430) patients were diagnosed to have subclinical hypothyroidism (normal serum free T4 and TSH >5.50 μIU/ml). Anti - TPO antibodies suggesting autoimmunity were detected in 21.85% (n = 1171) patients. The prevalence of hypothyroidism was high, affecting approximately one in 10 adults in the study population. Female gender and older age were found to have significant association with hypothyroidism. Subclinical hypothyroidism and anti-TPO antibody positivity were the other common observations.
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Subclinical Hypothyroidism (ScHt) affects 3-15% of the adult population. It's clinical and biochemical profile is not well defined, especially in Indian scenario. Our study aimed at screening normal population to define normative ranges of thyroid hormones and Serum thyroid stimulating hormone (S.TSH) and prevalence of ScHt and thyroid autoimmunity. Two-hundred thirty-seven normal subjects without family history of thyroid disease were evaluated for symptoms and laboratory tests for thyroid dysfunction and autoimmunity. The thyroid function tests were as follows: MEAN VALUES WERE: T3: 1.79 ± 0.42 ng/mL, T4: 10.23 ± 2.25 μg/dL, FT3: 1.88 ± 0.19 pg/mL, FT4: 1.12 ± 0.21 ng/dL, S.TSH: 2.22 ± 1.06 μlu/mL. 10.2% of euthyroid subjects had antimicrosomal antibodies (AMA) +ve (mean titer 1:918) and 23.6% were anti-thyroid peroxidase autoantibody (anti-TPO) +ve (mean titer 15.06 Au/mL). The euthyroid outlier range for S.TSH was 0.3-4.6 μlu/mL. The values were comparable in both the sexes. Those with S.TSH ≥ 5 μlu/mL were defined to have ScHt. Prevalence of ScHt was 11.3% (M:F ratio 1:3.7). 74% belonged to 35-54 years age group and prevalence increased with age (post-menopausal females: prevalence 20%). S.TSH was 9.8 ± 7.22 μlu/mL, mean S.AMA was 1:5079 (40.7% positivity) and mean S.anti-TPO was 260 Au/mL (47.6% positivity). Majority were agoitrous (74%), and stage I goiter was seen in 26% of this population. Symptom score of 5-8 was seen in 55% ScHt subjects versus 35% normal subjects. Mean S.TSH in our population was 2.22 μlu/mL (euthyroid outliers: 0.3-4.6 μlu/mL); hence, S.TSH above 4.6 μlu/mL should be considered as abnormal. The prevalence of thyroid autoimmunity increases after age of 35 years. ScHt presents mainly in agoitrous form and with positive antibodies, suggesting autoimmunity as the cause.
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The aim of this study is to report a rare case of massive pericardial effusion as initial manifestation of hypothyroidism. A previously healthy 21-year-old female patient suddenly began presenting dyspnea at rest and lower limb edema. Routine laboratory tests performed at admission showed hypothyroidism (TSH 146.14 mUI/L) and echocardiography showed significant pericardial effusion. Therapy was instituted with levothyroxine, resulting in clinical improvement without pericardiocentesis. The patient was followed up for 1 year, with total remission of dyspnea and edema. However, she developed typical symptoms of hypothyroidism, and remained with asthenia, dyslipidemia, weight gain, and mild pericardial effusion at the end of one year, even with the optimization of the levothyroxine dose. This case highlights the need for early investigation of hypothyroidism in patients with pericardial effusion.
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Increasing evidence derived from experimental and clinical studies suggests that the hypothalamic-pituitary-thyroid axis (HPT) and the hypothalamic-pitutitary-ovarian axis (HPO) are physiologically related and act together as a unified system in a number of pathological conditions. The suggestion that specific thyroid hormone receptors at the ovarian level might regulate reproductive function, as well as the suggested influence of estrogens at the higher levels of the HPT axis, seems to integrate the reciprocal relationship of these two major endocrine axes. Both hyper- and hypothyroidism may result in menstrual disturbances. In hyperthyroidism the most common manifestation is simple oligomenorrhea. Anovulatory cycles are very common. Increased bleeding may also occur, but it is rare. Hypothyroidism in girls can cause alterations in the pubertal process; this is usually a delay, but occasionally it can result in pseudoprecocious puberty. In mature women hypothyroidism usually is associated with abnormal menstrual cycles characterized mainly by polymenorrhea, especially anovulatory cycles, and an increase in fetal wastage.
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We report what is to the best of our knowledge the second adult case of chylothorax clearly associated with severe hypothyroidism in the English-language medical literature. To the best of our knowledge, this is the first case of its kind reported without a prior history of malignancy. A 37-year-old Hispanic woman with no reported significant past medical history initially presented with shortness of breath and inability to lose weight. She was found to have a large chylous effusion requiring chest-tube drainage, as well as severe hypothyroidism. After several weeks of thyroid hormone-replacement therapy, the formation of chylous pleural fluid in the patient greatly diminished, and the chest tube was removed. Upon long-term follow-up her minimal residual effusion remains stable on serial chest radiographs. Although the exact pathophysiologic relation between low thyroid hormone levels and chyle formation remains to be elucidated, hypothyroidism should be a diagnostic consideration in patients with chylous effusions, especially those refractory to conventional treatments.
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NHANES III measured serum TSH, total serum T(4), antithyroperoxidase (TPOAb), and antithyroglobulin (TgAb) antibodies from a sample of 17,353 people aged > or =12 yr representing the geographic and ethnic distribution of the U.S. population. These data provide a reference for other studies of these analytes in the U.S. For the 16,533 people who did not report thyroid disease, goiter, or taking thyroid medications (disease-free population), we determined mean concentrations of TSH, T(4), TgAb, and TPOAb. A reference population of 13,344 people was selected from the disease-free population by excluding, in addition, those who were pregnant, taking androgens or estrogens, who had thyroid antibodies, or biochemical hypothyroidism or hyperthyroidism. The influence of demographics on TSH, T(4), and antibodies was examined. Hypothyroidism was found in 4.6% of the U.S. population (0.3% clinical and 4.3% subclinical) and hyperthyroidism in 1.3% (0.5% clinical and 0.7% subclinical). (Subclinical hypothyroidism is used in this paper to mean mild hypothyroidism, the term now preferred by the American Thyroid Association for the laboratory findings described.) For the disease-free population, mean serum TSH was 1.50 (95% confidence interval, 1.46-1.54) mIU/liter, was higher in females than males, and higher in white non-Hispanics (whites) [1.57 (1.52-1.62) mIU/liter] than black non-Hispanics (blacks) [1.18 (1.14-1.21) mIU/liter] (P < 0.001) or Mexican Americans [1.43 (1.40-1.46) mIU/liter] (P < 0.001). TgAb were positive in 10.4 +/- 0.5% and TPOAb, in 11.3 +/- 0.4%; positive antibodies were more prevalent in women than men, increased with age, and TPOAb were less prevalent in blacks (4.5 +/- 0.3%) than in whites (12.3 +/- 0.5%) (P < 0.001). TPOAb were significantly associated with hypo or hyperthyroidism, but TgAb were not. Using the reference population, geometric mean TSH was 1.40 +/- 0.02 mIU/liter and increased with age, and was significantly lower in blacks (1.18 +/- 0.02 mIU/liter) than whites (1.45 +/- 0.02 mIU/liter) (P < 0.001) and Mexican Americans (1.37 +/- 0.02 mIU/liter) (P < 0.001). Arithmetic mean total T(4) was 112.3 +/- 0.7 nmol/liter in the disease-free population and was consistently higher among Mexican Americans in all populations. In the reference population, mean total T(4) in Mexican Americans was (116.3 +/- 0.7 nmol/liter), significantly higher than whites (110.0 +/- 0.8 nmol/liter) or blacks (109.4 +/- 0.8 nmol/liter) (P < 0.0001). The difference persisted in all age groups. In summary, TSH and the prevalence of antithyroid antibodies are greater in females, increase with age, and are greater in whites and Mexican Americans than in blacks. TgAb alone in the absence of TPOAb is not significantly associated with thyroid disease. The lower prevalence of thyroid antibodies and lower TSH concentrations in blacks need more research to relate these findings to clinical status. A large proportion of the U.S. population unknowingly have laboratory evidence of thyroid disease, which supports the usefulness of screening for early detection.
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Subclinical hypothyroidism is a frequent syndrome affecting about 10 million people in the United States. The management of such patients is open to debate. In a long-term prospective study we analyzed the spontaneous course and the value of predictive factors in the development of overt thyroid failure. We studied 82 female patients with subclinical hypothyroidism prospectively over a mean observation period of 9.2 yr. TSH, thyroid hormones, thyroid reserve after TRH administration, thyroid antibodies, and clinical parameters were assessed at yearly intervals. The cumulative incidence of overt hypothyroidism was calculated using life-table analysis and Kaplan-Meier curves. According to the initial serum TSH concentrations (TSH, 4-6/>6-12/>12 mU/liter), Kaplan-Meier estimates of the incidence of overt hypothyroidism were 0%, 42.8%, and 76.9%, respectively, after 10 yr (P < 0.0001). When only patients with TSH levels greater than 6 mU/liter were analyzed, the cumulative incidence was 55.3%. The incidence of overt hypothyroidism increased in patients with impaired thyroid reserve (52.6% vs. 38.1%; P = 0.05) and positive microsomal antibodies (58.5% vs. 23.2%; P = 0.03). This prospective long-term study demonstrates that only a part of the cohort of patients with subclinical hypothyroidism develops overt hypothyroidism over time and that a major group remains in the subclinical state after 10 yr. The measurement of TSH, microsomal (thyroperoxidase) antibodies, and thyroid reserve allows initial risk stratification for the development of overt thyroid failure (risk ratio ranging from 1.0-15.6). Our study helps to recognize the spontaneous course of subclinical hypothyroidism and in the identification of patients most likely to progress to overt hypothyroidism.
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The prevalence of thyroid dysfunction in relation to iodine intake was studied in adults (n = 1061) in five coastal areas of Japan that produce iodine-rich seaweed (kelp). The prevalence of hyperthyroidism (TSH < 0.15 mU/L) was similar in these areas, whereas that of hypothyroidism (TSH > 5.0 mU/L) varied from 0-9.7%. The relative frequency of above normal iodide concentration in the morning urine (≥ or = 75 mumol/L) [high urinary iodide (UI)] varied from 3.7%-30.3%. Together with previously reported results of a noncoastal city, the frequency of high UI correlated significantly with that of hypothyroidism with negative thyroid autoantibody (r = 0.829, n = 6, P < 0.05) but not with positive thyroid autoantibody (r = 0.278, NS) or with that of hyperthyroidism (r = 0.038, NS). Hypothyroidism was more prevalent in thyroid autoantibody-negative subjects with high UI (group II, 12.1%) than with normal UI (group I, 2.3%) (P < 0.001). The TSH [21.9(6.5-73.7)mU/L] (mean ± SD) and thyroglobulin [288 (182-456) μg/L] levels in group II were significantly higher than the respective levels in group I [9.6(3.7-25.3)mU/L and 123 (38-399) μg/L] (P < 0.05). Free T4of group II (9.9 ± 3.9 pmol/L) was significantly lower than in group I (14.2 ± 3.9 pmol/L) (P < 0.05). These results indicate that 1) the prevalence of hypothyroidism in iodine sufficient areas may be associated with the amount of iodine ingested; 2) hypothyroidism is more prevalent and marked in subjects consuming further excessive amounts of iodine; and 3) excessive intake of iodine should be considered an etiology of hypothyroidism in addition to chronic thyroiditis in these areas.
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The last 2 decades it has become clear that iodine deficiency has a modulating effect on the thyroid autoimmune response in humans. Also, in animals that spontaneously develop autoimmune thyroid disease, evidence is accumulating that a low iodine intake can modulate thyroid autoimmune reactivity. However, it is still not clear what the effect of a low iodine intake on thyroid autoimmune reactivity is in normal nonautoimmune animals. To study the relationship of a dietary low iodine intake on the thyroid autoimmune reactivity in nonautoimmune animals, normal Wistar rats (female) were kept on an enriched iodine diet (daily iodine intake of 100 rg iodine), a “for our area normal” (conventional) diet (COD; daily iodine intake of ‘7 pg iodine), a low iodine diet (LID; 2 days of 1% KCLO,, followed by iodinedeficient drinking water/pellets), or an extremely low iodine diet (LID+; 1% KCLO, continuously in the drinking water and iodine-deficient pellets). The enriched iodine diet rats were euthyroid (T3, -8 nM/liter; T,, -50 nM/liter; TSH, -2 rig/ml), had a normal thyroid weight (-12.5 mg), and showed only minimal signs of local thyroid immune reactivity; low numbers of intrathyroidal dendritic cells (DC; -35 DC/mm*), CD4+ cells (-2 cells/mm*), and CD8’ cells (-2.5 cells/mm*) were found in combination with low anticolloid antibody production (incidence of positive animals, 12.5%). The COD resulted in a normal thyroid function. The rats were euthyroid (range of Ta, 1.6-1.2 rl T,, -50 nM/liter; TSH, -2 rig/ml) and had a normal thyroid weight (-12.5 mg). However, some ss -3 CD4-positive (CD+) cells/mm’; -3 CD8+ cells/mm*; together with a 30% incidence of anticolloid antibodies]. The LID and LID+ not only induced goiter formation [thyroid weight, 27.3 f 4.2 mg (mean f
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An estimated 108 million people in India suffer from endocrine and metabolic disorders, with the poor mainly bearing the brunt of the disease. Several of these diseases are caused by environmental factors, are preventable and can be also be effectively treated at affordable cost. Yet a majority of them remain undiagnosed and untreated due to the lack of technology use. There is an urgent need for policy initiative at the national level to facilitate wide, cost effective and reliable use of immunoassay technology to measure hormones and metabolites and thus help diagnose and treat endocrine and metabolic disorders in the country.
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Serous effusions have been thought to be an unusual complication of hypothyroidism and most commonly have been associated with ascites, pericardial fluid and heart failure. Pleural fluid as an isolated finding in hypothyroidism is apparently rare and complete analysis of these hypothyroid-associated pleural effusions has not been described. To determine the frequency, chemical characteristics and clinical associations of hypothyroidism and pleural effusions, the medical records of 128 patients with hypothyroidism (defined by an increased serum TSH concentration) were reviewed. The majority of effusions in patients with hypothyroidism were due to other diseases. Effusions solely due to hypothyroidism appeared to be a real entity. These effusions were borderline between exudates and transudates and showed little evidence of inflammation.
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The aim of the study was to estimate dynamics of hematological disturbances in autoimmune thyroiditis and subclinical hypothyroidism (SH) during substitution therapy and without it and to elucidate factors promoting successful correction. The control group included 36 women, 60 others had SH. They were matched for age, BMI, free T3 level but differed in TSH (1.8 +/- 0.81 vs 7.0 +/- 3.41 mcunits/ml, p < 0.001) and T4 (p < 0.001) levels. 53 women with SH were followed up for 1 year; 18 of them were not treated (subgroup A) while 35 were given levothyroxin (subgroup B). The following red blood parameters were measured hemoglobin (Hb), ferritin, mean erythrocyte volume, erythrocyte Hb content and concentration, blood iron (Fe) level. SH was characterized by decreased (compared with control) Hb levels (125.8 +/- 13.75 and 133.2 +/- 9.12 g/l, p = 0.005), erythrocyte volume (p = 0.022), Hb content per erythrocyte (p = 0.001), ferritin (24.6 +/- 20.56 vs 36.6 +/- 30.66 mcg/l, p = 0.02), and Fe (p = 0.001). The frequency of anemia (28.3 vs 11.1%, p = 0.039) especially microcytic anemia (p = 0.035) increased A year later women of subgroup A showed further decrease in ferritin level (p = 0.011) and increase in anemia frequency (p = 0.016): microcytic (p = 0.23) and normocytic (p = 0.015). In subgroup B, the frequency of anemia decreased (p = 0.001) while ferritin, Fe and Hb levels slightly increased (p > 0.05). The best effect of therapy and highest rise in ferritin level were documented in younger patients (p = 0.06), in the absence of obesity (p = 0.003) and at the low initial ferritin level (p < 0.001). In regression analysis, ferritin level (094 [0.89; 0.99], p = 0.035) proved the most significant predictor of therapeutic effectiveness. SH was characterized by Fe deficiency, tendency to microcytosis and anemia that progressed in the absence of therapy. Substitution therapy promotes normalization of hematological problems especially in young and non-obese patients. Sideropenic syndrome suggests potential benefits of levothyroxin therapy and may be regarded as an additional indication for its prescription.
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Of 344 relatively healthy persons older than 60 years, 22 (5.9%) had a clearly elevated level of serum thyrotropin (TSH) (>10 μU/mL), a finding more common in women than in men. Ten of the 22 had low values for serum thyroxine (T4) and free T4 (FT4) index, but only one had a low value for serum triiodothyronine (T3) or free T3 (FT3) index. A further 14.4% had a slightly elevated level of serum TSH (>5≤10 μU/mL), but none had low values for serum T4 or FT4 index. Age alone has little effect on the measurements of T4; age is associated with slightly lower T3 levels, but only in men 60 years or older or in women 80 years or older. Longitudinal studies should determine if a slightly elevated serum TSH rises further with age and if there is a causal relationship between a high level of serum TSH and cardiovascular disease.(JAMA 242:247-250, 1979)
Article
SUMMARYA survey has been conducted in Whickham, County Durham, to determine the prevalence of thyroid disorders in the community. Two thousand seven hundred and seventy-nine people (82.4% of the available sample) were seen in the survey. The prevalence of overt hyperthyroidism was 19/1000 females rising to 27/1000 females when possible cases were included, compared with 1.6–2.3/1000 males. The prevalence of overt hyothyroidism was 14/1000 females rising to 19/1000 females when possible cases were included, compared with less than 1/1000 males. The prevalence of spontaneous overt hypothyroidism (excluding iatrogenic cases) was 10/1000 females or 15/1000 females including unconfirmed cases. Minor degrees of hypothyroidism were defined on the basis of elevated serum thyrotrophin (TSH) levels in the absence of obvious clinical features of hypothyroidism. TSH levels did not vary with age in males but increased markedly in females after the age of 45 years. The rise of TSH with age in females was virtually abolished when persons with thyroid antibodies were excluded from the sample. TSH levels above 6 mu/1 were shown to reflect a significant lowering of circulating thyroxine levels and showed a strong association with thyroid antibodies in both sexes, independent of age. Elevated TSH levels (>6mu/l) were recorded in 7.5% of females and 2.8% of males of all ages. Thyroglobulin antibodies were present in 2% of the sample. Thyroid cytoplasmic antibodies were present in 6.8% of the sample (females 10.3%, males 2.7%) and their frequency did not vary significantly with age in males but increased markedly in females over 45 years of age. 3% of the sample (females 5.1%, males 1.1%) had thyroid antibodies and elevated TSH levels and the relative risk of a high TSH level in subjects with antibodies was 20:1 for males and 13:1 for females, independent of age. Small goitres (palpable but not visible) were found in 8.6% of the sample and obvious goitres (palpable and visible) in 6.9%. Goitres were four times more common in females than in males and were most commonly found in younger rather than older females. TSH levels were slightly but not significantly lower in those with goitre than in those without goitre. There was a weak association between goitre and antibodies in females but not males.
Article
Excess iodine ingestion has been implicated in induction and exacerbation of autoimmune thyroiditis in human populations and animal models. We studied the time course and sex-related differences in iodine-induced autoimmune thyroiditis in NOD-H-2h4mice. This strain, derived from a cross of NOD with B10.A(4R), spontaneously develops autoimmune thyroiditis but not diabetes. NOD-H-2h4mice were given either plain water or water with 0.05% iodine for 8 weeks. Approximately 54% of female and 70% of male iodine-treated mice developed thyroid lesions, whereas only 1 of 20 control animals had thyroiditis at this time. Levels of serum thyroxin (T4) were similar in the treatment and control groups. Thyroglobulin-specific antibodies were present in the iodine-treated group after 8 weeks of treatment but antibodies to thyroid peroxidase were not apparent in the serum of any of the animals. Levels of thyroglobulin antibodies increased throughout the 8-week iodine ingestion period; however, no correlation was seen between the levels of total thyroglobulin antibodies and the degree of thyroid infiltration at the time of autopsy. The thyroglobulin antibodies consisted primarily of IgG2a, IgG2b, and IgM antibodies with no detectable IgA, IgG1, or IgG3 thyroglobulin-specific antibodies. The presence of IgG2b thyroglobulin-specific antibodies correlated well with the presence of thyroid lesions.
Article
To evaluate the trends relative to incidence of Hashimoto's thyroiditis and Graves' disease from 1935 through 1967, records of all diagnosed cases occurring in residents of Rochester, Minnesota, were identified through the facilities of the Rochester-Olmsted County epidemiologic program. During those 33 yr, 246 cases of Hashimoto's thyroiditis and 256 cases of Graves' disease were diagnosed in the subject population. The average annual incidence rates per 100,000 for Hashimoto's thyroiditis for females increased from 6.5 (1935–1944) to 21.4 (1945–1954) to 67.0 (1955–1964) to 69.0 (1965–1967). There was no indication that the incidence of Graves' disease changed in any significant or consistent pattern during the 33 yr. The average annual rate for females was 36.8/100,000/yr for all age groups; the rate was highest among women 20–39 yr old.
Article
Thyroid abnormalities are common in all populations, but it is difficult to compare results of epidemiological studies, because different methods have been used for evaluation. We studied the importance of the population iodine intake level for the prevalence rate of various thyroid abnormalities in elderly subjects. Random samples of elderly subjects (68 yr) were selected from the central person registers in Jutland, Denmark, with low (n = 423) and, in Iceland, with longstanding relatively high (n = 100) iodine intake. Females from Jutland had a high prevalence of goiter or previous goiter surgery (12.2%), compared with males from Jutland (3.2%) and females (1.9%) and males (2.2%) from Iceland. Abnormal thyroid function was very common in both areas, with serum TSH outside the reference range in 13.5% of subjects from Jutland and 19% of those from Iceland. In Jutland, it was mainly thyroid hyperfunction (9.7% had low, 3.8% had high serum TSH), whereas in Iceland, it was impaired thyroid function (1% had low, 18% had high serum TSH). All subjects with serum TSH more than 10 mU/L had autoantibodies in serum, but antibodies were, in general, more common in Jutland than in Iceland. Thus, thyroid abnormalities in populations with low iodine intake and those with high iodine intake develop in opposite directions: goiter and thyroid hyperfunction when iodine intake is relatively low, and impaired thyroid function when iodine intake is relatively high. Probably, mild iodine deficiency partly protects against autoimmune thyroid disease. Thyroid autoantibodies may be markers of an autoimmune process in the thyroid or secondary to the development of goiter.
Article
Pleural and pericardial effusion is a rare complication of severe hypothyroidism in children but can be present in 10 to 30% of adults. Most pediatric cases have been in children with Down syndrome. In this report, six cases of pericardial effusion in children with severe hypothyroidism with and without trisomy 21 are presented. In all patients, the pericardial effusion was managed successfully without pericardiocentesis. The effusions resolved completely in 2 to 12 months after initiation of thyroxin replacement. In conclusion, hypothyroidism should be considered in any child with unexplained pericardial or pleural effusions. Early recognition and treatment with thyroid hormone replacement could eliminate the need for unnecessary diagnostic procedures and invasive treatment measures and reduce the risk of progression to cardiac tamponade.
Article
India is in the transition phase from iodine deficiency to iodine sufficiency, and this is expected to change the thyroid status of the population. The thyroid status and auto-immune status of adult Indian population in the postiodisation phase is largelyunknown, and this study was conducted to answer this question. A cross-sectional population survey was conducted in two phases among the residents of urban coastal area of central Kerala. The initial phase included a house-to-house survey of 3069 adults (>18 years of age), selected by cluster sampling method. From the surveyed population, 986 subjects underwent further physical examination and biochemical evaluation for thyroid function, thyroid autoimmunity status and iodine status. The total prevalence of goitre was 12.2% and median urine iodine excretion was 211.4 mcg/l (mean 220.3 +/- 99.5 mcg/l) indicating iodine sufficiency. Thyroid function abnormalities were present in 19.6% of subjects. Subclinical hypothyroidism was present in 9.4%. Among the population with normal thyroid function, 9.5% and 8.5% respectively had positive anti-TPO and anti-TG antibodies. Among those with thyroid dysfunction, 46.3% had positive anti-TPO and 26.8% were anti-TG positive. A significant proportion of this iodine-sufficient adult population had thyroid disorders. Further studies are required to characterise the reasons for this high prevalence. Iodine deficiency as well as thyroid dysfunction should both be the focus of public health strategies in susceptible populations.
Article
In an area of severe endemic goiter in Central Java, Indonesia, clinical overt or mild hypothyroidism appeared to be present in 7 out of 20 cretins and also in 12 out of 94 non-cretinous subjects, all 5-20 years of age, living in the village of Sengi. Hypothyroidism was not found in a control group of 70 subjects of the same age living in Londjong just outside the edemia. In hypothyroid subjects the plasma PBI-concentration was 0.98+/-0.32 mug/100 ml (mean+/-SD) vs. 2.72+/-1.24 mug/100 ml in euthyroid subjects from Sengi and 4.86+/-0.80 mug/100 ml in controls from Londjong. Values for T3 were 56.3+/-3.17 ng/100 ml in hypothyroids, 140.5+/-38.5 ng/100 ml in euthyroids from Sengi and 121.6+/-27.4 ng/100 ml in controls. The TSH levels (geometric mean and range) in these 3 groups were, respectively, 210.1 (108.0-342), 15.6 (3.0-372) and 4.1 (0.8-7.0) muU/ml. The differences between the mean concentration of PBI, T3 and TSH in the hypothyroid and euthyroid groups were highly significant (P less than 0.001). These data strengthen the clinical diagnosis of hypothyroidism in cretins as well as in non-cretinous subjects. All hypothyroid subjects had a PBI less than 1.8 mug/100 ml and T3 less than 120 ng/100 ml and TSH greater than 100 muU/ml. In 8 hypothyroid subjects, restudied 18 months after iodized oil injection, hypothyroidism was either corrected or markedly improved. It therefore appears that iodine deficiency per se in postnatal life may lead to (juvenile) hypothyroidism, which can be corrected by iodine therapy. Our findings have implications for the definition and diagnosis of endemic cretinism. Not all hypothyroid subjects in an area of endemic iodine deficiency should be classified as cretins.
Article
The serum prolactin level was found to be elevated (>14.0 ng/ml) in 39 per cent of patients with untreated primary hypothyroidism, none of whom were receiving drugs known to affect serum prolactin levels. The mean serum thyroid-stimulating hormone (TSH) (± SEM), thyroxine (T4) and triiodothyronine (T3) levels prior to therapy were, respectively, 106.0 μU/ml ± 19.3, 0.9 μg/dl ± 0.2, 50.6 ng/dl ± 5.8. The mean serum prolactin level in the hypothyroid group (14.3 ng/ml ± 1.1; range: 4.7 to 42.0 ng/ml; 49 subjects) was significantly higher (P < 0.01) than in the euthyroid controls (8.2 ng/ml ± 0.5; range 5.1 to 14.0 ng/ml; 24 subjects). The mean serum prolactin level in the hypothyroid women (15.4 ng/ml ± 1.3; range 4.7 to 42.0 ng/ml; 39 subjects) was significantly higher (P < 0.002) than in the euthyroid female controls (8.1 ng/ml ± 0.7; range 5.1 to 14.0 ng/ml; 15 subjects). The mean serum prolactin level in the hypothyroid men (10.3 ng/ml ± 1.4; range 5.1 to 18 ng/ml; 10 subjects) was not significantly different from that in the male controls (8.3 ng/ml ± 0.7; range 5.3 to 13 ng/ml; nine subjects). A significant correlation was found between log serum prolactin and log serum TSH (r = 0.34, P < 0.05), suggesting that the elevated serum prolactin level in primary hypothyroidism may be mediated by a common factor, such as TRH. Despite the increased frequency of elevated serum prolactin levels, galactorrhea is an uncommon accompaniment of primary hypothyroidism.
Article
The spontaneous occurrence of, and recovery from primary hypothyroidism were observed after delivery in 6 women with autoimmune thyroiditis. Diffuse goiter was noticed 1-3 months after delivery. The blood thyroid hormone level was found to be lowest at 3-6 months post-partum, with a thyroxine iodine value of 1.0 +/- 0.6 mug/dl (mean +/- SD) (normal 3.0-7.2), triiodithyronine value of 77 +/- 11 ng/dl (normal 90-190) and T3 resin sponge uptake of 21 +/- 2.8% (normal 24-37). During this period the serum level of thyrotropin was increased to 307 +/- 235 muU/ml (normal less than 8) and 131I thyroid uptake in 24 hours was more than 60%. Then 6-9 months after delivery, the enlarged thyroid gland decreased in size, and the values in thyroid function tests returned to the normal range without any treatment. Anti-thyroglobulin antibodies were positive in 3 cases. Anti-thyroid microsomal antibodies were positive in all cases with titers of 1:10(4)-4:10(9), and titers were highest during the period of hypothyroidism and decreased thereafter. We suggest that these transient changes might be induced by pregnancy and delivery during the course of autoimmune thyroiditis.
Article
Qualitative and quantitative studies of erythropoiesis in 23 patients with hypothyroidism and 21 patients with hyperthryoidism included routine hematologic evaluation, bone marrow morphology, status of serum iron, B12 and folate red blood cell mass and plasma volume by radioisotope methods, erythrokinetics and radiobioassay of plasma erythropoietin. A majority of patients with the hypothyroid state had significant reduction in red blood cell mas per kg of body weight. The presence of anemia in many of these patients was not evident from hemoglobin and hematocrit values due to concomitant reduction of plasma volume. The erythrokinetic data in hypothyroid patients provided evidence of significant decline of the erythropoietic activity of the bone marrow. Erythroid cells in the marrow were depleted and also showed reduced proliferative activity as indicated by lower 3H-thymidine labeling index. Plasma erythropoietin levels were reduced, often being immeasurable by the polycythemic mouse bioassay technique. These changes in erythropoiesis in the hypothyroid state appear to be a part of physiological adjustment to the reduced oxygen requirement of the tissues due to diminished basal metabolic rate. Similar investigations revealed mild erythrocytosis in a significant proportion of patients with hyperthyroidism. Failure of erythrocytosis to occur in other patients of this group was associated with impaired erythropoiesis due to a deficiency of hemopoietic nutrients such as iron, vitamin B12 and folate. The mean plasma erythropoietin level of these patients was significantly elevated; in 4 patients the levels were in the upper normal range whereas in the rest, the values were above the normal range. The bone marrow showed erythyroid hyperplasia in all patients with hyperthyroidism. The mean 3H-thymidine labeling index of the erythroblasts was also significantly higher than normal in hyperthyroidism; in 8 patients the index was within the normal range whereas in the remaining 13 it was above the normal range. Erythrokinetic studies also provided evidences of increased erythropoietic activity in the bone marrow. It is postulated that thyroid hormones stimulate erythropoiesis, sometimes leading to erythrocytosis provided there is no deficiency of hemopoietic nutrients. Stimulation of erythropoiesis by thryoid hormones appears to be mediated through erythropoietin.
Article
An epidemiological survey on the incidence of juvenile chronic lymphocytic thyroiditis was performed in 10,220 apparently healthy school children in Ishikawa district, Japan. The subject of present study included 6,244 school children (2,831 boys and 3,413 girls, ages 6-18 yrs.) in Kanazawa City and 3,976 children (2,055 boys and 1,921 girls, ages 6-18 yrs.) in Wajima City. The first group was selected as a representative of urban area and the second group as that of seaside area. Children who have goiter or firm thyroid were selected for testing antithyroglobulin and anti-microsomal antibodies in sera. Final diagnosis of chronic lymphocytic thyroiditis was made on histological specimen obtained by needle biopsy on the antibody positive subjects. The overall incidence of chronic lymphocytic thyroiditis in these children was 3.0 per 1,000, whereas the incidence in adolescent girls was as high as 8.2 per 1,000. There was a considerable sex difference in the prevalence, the ratio of female to male was 6.5:1, and the incidence increased with age. The incidence in seaside area was 5.3 per 1,000 that was significantly higher than in urban area, 1.4 per 1,000 (p less than 0.005). Histologically, 26 of 30 cases (87%) were classified as focal thyroiditis and 4 cases (13%) were diffuse thyroiditis. Serum T4-I and T3 values within normal range in all patients, but resting TSH was elevated in 1 of 23 cases and TSH response to TRH was exaggerated in 3 of 23 cases. Impaired organification of iodide was observed in 6 of 32 cases by iodide-perchlorate discharge test. The present study demonstrates that juvenile chronic lymphocytic thyroiditis is highly prevalent among apparently healthy school children and early recognition of the disease with preventive care for hypothyroidism in future should be stressed.
Article
In an attempt to assess a possible relationship between pituitary size and TSH secretion, the volume of sella turcica was measured in 570 subjects, 26 primary hypothyroid patients, and 34 thyrotoxic patients. The volume of sella turcica, measured by a 3-dimensional approach, increased progressively with age until 20 years of age and was rather constant thereafter in normal subjects. In thyrotoxic patients, the volume of sella turcica was normal in spite of decreased plasma TSH concentration. In contrast, 81% of primary hypothyroid patients had an abnormal enlargement of the sella turcica. The magnitude of an increase of sella turcica inversely related with a decrease in serum T4 and T3 concentrations. On the other hand, the magnitude of an increase of sella turcica correlated well with an increase of circulating TSH. We suggest that an increase of sella turcica indirectly reflects an increase in pituitary size and TSH-secreting capacity, possibly due to hypertrophy and hyperplasia of TSH cells in primary hypothyroid patients.
Article
Increasing use of assays for TSH with improved sensitivity as a first-line test of thyroid function has raised questions regarding prevalence and clinical significance of abnormal results, especially values below normal. We have assessed the thyroid status of 1210 patients aged over 60 registered with a single general practice by measurement of serum TSH using a sensitive assay. High TSH values were more common in females (11.6%) than males (2.9%). TSH values below normal were present in 6.3% of females and 5.5% of males, with values below the limit of detection of the assay present in 1.5% of females and 1.4% of males. Anti-thyroid antibodies were found in 60% of those with high TSH but only 5.6% of those with subnormal TSH. Eighteen patients were hypothyroid (high TSH, low free thyroxine) and one thyrotoxic (low TSH, raised free thyroxine) at initial testing. Seventy-three patients with elevated TSH but normal free T4 were followed for 12 months; 13 (17.8%) developed low free T4 levels and commenced thyroxine, TSH returned to normal in four (5.5%) and 56 (76.7%) continued to have high TSH values. Sixty-six patients with TSH results below normal were followed. Of the 50 subjects with low but detectable TSH at initial testing, 38 (76%) returned to normal at 12 months; of those 16 with undetectable TSH followed, 14 (87.5%) remained low at 12 months. Only one subject (who had an undetectable TSH) developed thyrotoxicosis. In view of the marked prevalence of thyroid dysfunction in the elderly, we suggest that screening of all patients over 60 should be considered.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
The prevalence of thyroid dysfunction was determined in a healthy urban population over the age of 55 years. A highly sensitive serum thyrotropin assay was used initially to screen 968 subjects. Elevated values (greater than 6 mU/L) were found in 7.3%, while suppressed values (less than 0.1 mU/L) were present in 2.5% subjects. Protirelin stimulation testing demonstrated exaggerated responses in 95% of the subjects with elevated thyrotropin levels and subnormal responses in 81% of the subjects with suppressed thyrotropin levels. Thyroid dysfunction, as defined by abnormalities of both serum thyrotropin level and protirelin response, was calculated to be present in 8.9% of the population. The prevalence was greater in whites (vs blacks), in women, and in subjects older than 75 years as compared with the 55- to 64-year age group. Hypothyroidism was calculated to be present in 6.9% subjects. Despite an increased prevalence of thyroid autoantibodies in these subjects, only 8.5% of them had subnormal serum thyroxine concentrations. Hyperthyroidism was calculated to be present in 2.0% of the population, two thirds of whom were taking thyroid hormone preparations. These results suggest a significant prevalence of thyroid dysfunction in the elderly, with important sex and racial differences.
Article
Serous effusions have been thought to be an unusual complication of hypothyroidism and most commonly have been associated with ascites, pericardial fluid and heart failure. Pleural fluid as an isolated finding in hypothyroidism is apparently rare and complete analysis of these hypothyroid-associated pleural effusions has not been described. To determine the frequency, chemical characteristics and clinical associations of hypothyroidism and pleural effusions, the medical records of 128 patients with hypothyroidism (defined by an increased serum TSH concentration) were reviewed. The majority of effusions in patients with hypothyroidism were due to other diseases. Effusions solely due to hypothyroidism appeared to be a real entity. These effusions were borderline between exudates and transudates and showed little evidence of inflammation.
Article
A clinical scoring system for hypothyroidism was evaluated against an established "gold standard" (low serum thyroxine and elevated thyroid-stimulating hormone) in 52 adults in a peripheral hospital and in 53 adults in a endocrinology referral clinic. Using a score of 0 as a cutoff point, the scoring system selected patients with hypothyroidism from the referral center for further biochemical evaluation; at the same time, it excluded hypothyroidism with confidence in 42% of euthyroid subjects. In the peripheral hospital, a cutoff score of -10 selected 92% of hypothyroid subjects for further evaluation and excluded hypothyroidism in 55% of euthyroid subjects. Two cutoff points were needed because the prevalences of hypothyroidism in the two centers differed. The simple scoring system increased the pretest probability of disease by 15% in the peripheral hospital and by 19% in the referral clinic. In countries where resources are limited, this scoring system can improve the clinical evaluation of patients who have one or more symptoms of hypothyroidism and reduce the load on referral centers.
Article
In a prospectively planned study of 591 Danish women thyroid dysfunction after delivery was found in 23 (3.9%). Seven women were hypothyroid and 16 were thyrotoxic. In seven of the thyrotoxic subjects a hypothyroid phase followed. Thyroid dysfunction was mostly transient with complete resolution within a year but persisted in three women (13%). Three months after delivery a positive titre of thyroid microsomal antibodies (TMAb) was found in 38 women (6.4%). Positive titres of TMAb were more often found in women with thyroid dysfunction than in those without (20/38 vs. 3/553). Maximal TMAb titres were seen 5-6 months after delivery and were associated with the occurrence of hypothyroidism. Postpartum thyroid dysfunction was found more often in women with a personal or family history of autoimmune thyroid disorder.
Article
Thyrotropin (thyroid-stimulating hormone [TSH]) levels were elevated above 4.0 mU/L (microU/mL) in serum samples from 13.2% of 258 healthy elderly subjects. To investigate the natural history of progressive thyroid failure, serial thyroid functions were measured for four years in 26 of these subjects with elevated TSH levels. In one third of these subjects, biochemical thyroid failure developed (thyroxine level less than 58 nmol/L [4.5 micrograms/dL]) within the course of the study. All subjects with initial TSH levels above 20 mU/L (microU/mL), and 80% of those with high-titer thyroid antimicrosomal antibodies (regardless of initial TSH level), became overtly hypothyroid. Compared with subjects with high-titer antibody, those with antibody titer less than 1:1600 had lower TSH and higher thyroxine levels, and thyroid failure developed in none during the study. These results suggest that among older patients with isolated elevations of the TSH level, only those with markedly elevated TSH levels or high-titer antimicrosomal antibodies should be prophylactically treated with levothyroxine sodium replacement.
Article
It has been suggested that the incidence of Hashimoto's thyroiditis is increased in the presence of high iodide intake. The diabetes-prone BB/W rat develops spontaneous histological autoimmune lymphocytic thyroiditis (LT) without functional hypothyroidism between 60 and 120 days of age. Studies were carried out to determine whether iodine administration to BB/W rats would affect the incidence and severity of LT and induce hypothyroidism. Iodide (0.05% in water) or tap water (C) was administered ad libitum to 42 10-month-old BB/W rats and 71 30-day-old BB/W rats for 8 weeks. For control purposes, 0.05% iodide or tap water (C) was also administered ad libitum to 42 30-day-old nondiabetic and non-LT-prone BB/W genetically equivalent rats (W-line) for 12 weeks and 41 21-day-old Wistar rats for 7 weeks. In a separate experiment, weanling BB/W rats were fed a low iodine diet, a control iodine-sufficient (C) diet, or Purina chow (P) and tap water ad libitum for 8 weeks. In each experiment, blood was obtained at the time of death for the measurement of serum T4, T3, TSH, and antithyroglobulin antibody (anti-Tg Ab), and the thyroids were removed for histological evaluation (0 = no LT; 1-4 = LT). Iodide administration (0.05%) induced a significant increase in the incidence of LT in 30-day-old BB/W rats (I, 77%; C, 30%, P less than .001). Thyroid weight and serum T4, T3, and anti-Tg Ab concentrations were not affected by iodide administration. However, the presence of LT was associated with a significant increase in thyroid weight and anti-Tg Ab concentrations. BB/W rats subjected to a low iodine diet exhibited a significantly decreased incidence of LT (low I, 8.6%; C, 47.3%; P less than 0.01), but no statistically significant difference in anti-Tg Ab levels. Increased iodide intake did not significantly affect the incidence of LT in adult BB/W rats and did not induce LT or affect thyroid function in W-line or Wistar rats. These data show that iodine intake significantly affects the incidence of spontaneous LT in young, genetically predisposed rats.
Article
Clinical studies have suggested that excess dietary iodine promotes autoimmune thyroiditis; however, the lack of a suitable animal model has hampered investigation of the phenomenon. In this study, different amounts of potassium iodide were added to the diets of chicken strains known to be genetically susceptible to autoimmune thyroiditis. Administration of iodine during the first 10 weeks of life increased the incidence of the disease, as determined by histology and the measurement of autoantibodies to triiodothyronine, thyroxine, and thyroglobulin. Further support for the relation between iodine and autoimmune thyroiditis was provided by an experiment in which iodine-deficient regimens decreased the incidence of thyroid autoantibodies in a highly susceptible strain. These results suggest that excessive consumption of iodine in the United States may be responsible for the increased incidence of autoimmune thyroiditis.
Article
One hundred and sixty-three asymptomatic people with thyroid antibodies or raised serum thyrotrophin (TSH) concentrations, or both, and 209 age-matched and sex-matched controls without either marker of thyroid disorder were followed up for four years to determine the natural history of autoimmune thyroiditis. Mildly raised TSH concentrations alone and the presence of thyroid antibodies alone did not significantly increase the risk of developing overt hypothyroidism during the four years compared with the controls. Overt hypothyroidism developed at the rate of 5% a year in women who initially had both raised TSH concentrations and thyroid antibodies. Prophylactic treatment with thyroxine may be justified in women found to have both markers of impending thyroid failure. The cost effectiveness of screening the adult population remains to be evaluated.
Article
The original Whickham Survey documented the prevalence of thyroid disorders in a randomly selected sample of 2779 adults which matched the population of Great Britain in age, sex and social class. The aim of the twenty-year follow-up survey was to determine the incidence and natural history of thyroid disease in this cohort. Subjects were traced at follow-up via the Electoral Register, General Practice registers, Gateshead Family Health Services Authority register and Office of Population Censuses and Surveys. Eight hundred and twenty-five subjects (30% of the sample) had died and, in addition to death certificates, two-thirds had information from either hospital/General Practitioner notes or post-mortem reports to document morbidity prior to death. Of the 1877 known survivors, 96% participated in the follow-up study and 91% were tested for clinical, biochemical and immunological evidence of thyroid dysfunction. Outcomes in terms of morbidity and mortality were determined for over 97% of the original sample. The mean incidence (with 95% confidence intervals) of spontaneous hypothyroidism in women was 3.5/1000 survivors/year (2.8-4.5) rising to 4.1/1000 survivors/year (3.3-5.0) for all causes of hypothyroidism and in men was 0.6/1000 survivors/year (0.3-1.2). The mean incidence of hyperthyroidism in women was 0.8/1000 survivors/year (0.5-1.4) and was negligible in men. Similar incidence rates were calculated for the deceased subjects. An estimate of the probability of the development of hypothyroidism and hyperthyroidism at a particular time, i.e. the hazard rate, showed an increase with age in hypothyroidism but no age relation in hyperthyroidism. The frequency of goitre decreased with age with 10% of women and 2% of men having a goitre at follow-up, as compared to 23% and 5% in the same subjects respectively at the first survey. The presence of a goitre at either survey was not associated with any clinical or biochemical evidence of thyroid dysfunction. In women, an association was found between the development of a goitre and thyroid-antibody status at follow-up, but not initially. The risk of having developed hypothyroidism at follow-up was examined with respect to risk factors identified at first survey. The odds ratios (with 95% confidence intervals) of developing hypothyroidism with (a) raised serum TSH alone were 8 (3-20) for women and 44 (19-104) for men; (b) positive anti-thyroid antibodies alone were 8 (5-15) for women and 25 (10-63) for men; (c) both raised serum TSH and positive anti-thyroid antibodies were 38 (22-65) for women and 173 (81-370) for men. A logit model indicated that increasing values of serum TSH above 2mU/l at first survey increased the probability of developing hypothyroidism which was further increased in the presence of anti-thyroid antibodies. Neither a positive family history of any form of thyroid disease nor parity of women at first survey was associated with increased risk of developing hypothyroidism. Fasting cholesterol and triglyceride levels at first survey when corrected for age showed no association with the development of hypothyroidism in women. This historical cohort study has provided incidence data for thyroid disease over a twenty-year period for a representative cross-sectional sample of the population, and has allowed the determination of the importance of prognostic risk factors for thyroid disease identified twenty years earlier.
Article
The prevalence of thyroid dysfunction in relation to iodine intake was studied in adults (n = 1061) in five coastal areas of Japan that produce iodine-rich seaweed (kelp). The prevalence of hyperthyroidism (TSH < 0.15 mU/L) was similar in these areas, whereas that of hypothyroidism (TSH > 5.0 mU/L) varied from 0-9.7%. The relative frequency of above normal iodide concentration in the morning urine (> or = 75 mumol/L) [high urinary iodide (UI)] varied from 3.7%-30.3%. Together with previously reported results of a noncoastal city, the frequency of high UI correlated significantly with that of hypothyroidism with negative thyroid autoantibody (r = 0.829, n = 6, P < 0.05) but not with positive thyroid autoantibody (r = 0.278, NS) or with that of hyperthyroidism (r = 0.038, NS). Hypothyroidism was more prevalent in thyroid autoantibody-negative subjects with high UI (group II, 12.1%) than with normal UI (group I, 2.3%) (P < 0.001). The TSH [21.9(6.5-73.7)mU/L] (mean +/- SD) and thyroglobulin [288 (182-456) micrograms/L] levels in group II were significantly higher than the respective levels in group I [9.6(3.7-25.3)mU/L and 123 (38-399) micrograms/L] (P < 0.05). Free T4 of group II (9.9 +/- 3.9 pmol/L) was significantly lower than in group I (14.2 +/- 3.9 pmol/L) (P < 0.05). These results indicate that 1) the prevalence of hypothyroidism in iodine sufficient areas may be associated with the amount of iodine ingested; 2) hypothyroidism is more prevalent and marked in subjects consuming further excessive amounts of iodine; and 3) excessive intake of iodine should be considered an etiology of hypothyroidism in addition to chronic thyroiditis in these areas.
Article
We assessed the relative risk of both serum TSH and antithyroid antibody concentrations with regard to progression of thyroid failure and studied the lipid profiles of individuals with elevated TSH levels. In a randomly selected group of 427 women aged 40-60 (mean 55) years volunteering in an epidemiological survey in Zoetermeer, TSH and thyroid microsomal antibodies (TMA) were determined. Ten years after the initial survey only TSH was measured and the lipid profiles of the individuals with elevated serum TSH levels were studied and compared with a reference group. During follow-up, four of 427 women were treated with thyroxine. Seventeen of 423 women initially had elevated serum concentrations of TSH (> 4.2 mU/l), 11 of whom were TMA positive. In the group of 406 women with initially a normal TSH, nine out of 37 (24%) TMA-positive women developed elevated serum levels of TSH over 10 years. In contrast only 10 of 369 (3%) TMA-negative women had elevated serum TSH levels 10 years after the initial survey (P < 0.001). Altogether, at the end of the observation period, 40% of TMA-positive subjects had elevated serum TSH concentrations, compared to 3% in the TMA-negative group (P < 0.01). TSH levels in the upper part of the normal range also appeared to have a predictive value: if those both with TSH levels between 2.0 and 4.2 and with a positive TMA status were contrasted with those without antibodies and low TSH, the crude relative risk was 71.5 (31.0-164.3), whereas the crude relative risk of presence versus absence of TMA was only 36.3 (18.8-70.3). Women with elevated TSH levels did not show changes in serum concentrations of total cholesterol (7.4 +/- 1.1 mmol/l), apo-A, (4.7 +/- 1.0 mmol/l) and apo-B (3.1 +/- 0.7 mmol/l) lipoproteins, compared with control individuals (7.2 +/- 1.3, 4.7 +/- 0.8 and 3.0 +/- 0.7 mmol/l, respectively). The determination of serum TMA in middle-aged women can identify an important group of women at risk of developing an elevated serum TSH. TMA measurement is of potential use in the prevention of cardiovascular disease. An elevated serum TSH, however, in our study-group does not seem to be accompanied by an abnormal lipid profile, as reported by others.
Article
To determine the natural course of the syndrome "subclinical hypothyroidism." Prospective study of 30 subjects with "subclinical hypothyroidism," as documented precisely by normal serum thyroxine and triiodothyronine concentrations and high serum thyrotropin levels on three occasions at intervals of 2 to 3 weeks. The subjects were followed up for 4 to 15 years (mean, 8.2 +/- 2.3 years), with repeated determinations of thyroid hormone indices at intervals of 3 to 6 months. Endocrinology Clinic at the Veterans Affairs Medical Center. 16 subjects developed definitive primary hypothyroidism within 3 months to 2 years, as reflected by a progressive rise in serum thyrotropin level with a gradual decline in serum thyroxine and triiodothyronine concentrations, with serum thyroxine levels falling to subnormal concentrations. In 14 of these subjects, primary hypothyroidism could be attributed to known etiologic factors, whereas in the remaining two the cause was not apparent. Persistently elevated serum thyrotropin with normal serum thyroxine and triiodothyronine concentrations following a cyclic pattern was observed in 14 subjects during the follow-up period. In 11 of these subjects, there was a history of non-radical surgery or conventional radiation therapy to the neck area, whereas in the remaining three subjects, no apparent cause could be identified. "Subclinical hypothyroidism" is not always a forerunner of primary hypothyroidism. Two distinct populations evolve: (1) those with true preclinical or subclinical hypothyroidism, which may be predicted by the presence of one of the well-known etiologic factors responsible for onset of primary hypothyroidism, and (2) euthyroidism with reset thyrostat--a permanent state without a definitive progression to hypothyroidism, most probably secondary to a previous subtle insult to the thyroid gland.
Article
To investigate the effect of varying amounts of iodine intake on the prevalence of thyroid dysfunction, autoimmunity and goitre in old age. The first screening study where elderly subjects with varying amounts of iodine supply but from the same geographical and ethnographical region (Carpathian basin) were compared, and all hormone measurements and ultrasonography were performed by the same laboratory or person. Nursing home residents were screened for thyroid disorders from: (A) an iodine-deficient area, Northern Hungary (n = 119; median age 81 years; median iodine excretion (MIE) 0.065 mumol/mmol creatinine (equivalent to 72 micrograms/g creatinine); (B) an area of obligatory iodinated salt prophylaxis since the 1950s, Slovakia (n = 135; median age 81 years, MIE 0.090 mumol/mmol creatinine (equivalent to 100 micrograms/g creatinine)) and (C) an abundant iodine intake area, Eastern Hungary (n = 92; median age 78 years; MIE 0.462 mumol/mmol creatinine (equivalent to 513 micrograms/g creatinine)). TSH, T4, free T4, T3, thyroglobulin (Tg), antibodies to Tg (AbTg) and to thyroid peroxidase (AbTPO), iodine excretion, ultrasonography of the thyroid gland. In regions A, B, and C, the prevalence of unsuspected clinical hypothyroidism was 0.8%, 1.5% and 7.6% (P = 0.006), with all cases except one being antibody positive (Ab+). The occurrence of subclinical hypothyroidism was 4.2% in region A, 10.4% in region B and 23.9% in region C (P < 0.001), but only 3 of 22 cases with subclinical hypothyroidism from region C were Ab+. The overall prevalence of Ab positivity (either antiTg+ or antiTPO+) was similar in the three regions (A, 19.3%; B, 24.4%; C, 22.8%). The occurrence of hyperthyroidism (clinical plus subclinical) was 3.4% in region A, 3.0% in region B and 0% in region C (not significant). The rate of elevated Tg levels was similar in the three regions. The prevalence of goitre was 39.4%, 16.4% and 12.2% (P < 0.001), respectively in regions A, B and C. In euthyroid subjects the mean ultrasonographically determined thyroid volume was 21.9 ml in region A, 13.6 ml in region B and 15.1 ml in region C (ANOVA F = 5.76; P = 0.0038). There was no significant difference in the occurrence of cases with hypoechogenic echotexture of the thyroid gland. The screening for hypothyroidism in nursing home residents living in iodine-rich regions is justified by the high prevalence of unsuspected clinical hypothyroidism. The high prevalence of antibody positivity in old age is independent of the iodine supply, but iodine supply has a determining role in the development of autoimmune hypothyroidism in the aged. Most cases of subclinical hypothyroidism in iodine-rich regions are not of autoimmune origin. In old age, hypoechogenic texture of the thyroid gland is not predictive of thyroid dysfunction.
Article
To review information on the benefits of screening with a sensitive thyroid-stimulating hormone (TSH) test for thyroid dysfunction in asymptomatic patients seeking primary care for other reasons. This paper focuses on whether screening should be aimed at detection of subclinical thyroid dysfunction and whether persons with mildly abnormal TSH levels can benefit. A MEDLINE search for studies of screening for thyroid dysfunction and of treatment for complications of subclinical thyroid dysfunction. Studies of screening with thyroid function tests in the general adult population or in patients seen in the general office setting were selected (n=33). All controlled studies of treatment in patients with subclinical hypothyroidism or subclinical hyperthyroidism were also included (n=23). The prevalence of overt and subclinical thyroid dysfunction, the evidence for the efficacy of treatment, and the incidence of complications in defined age and sex groups were extracted from each study. Screening can detect symptomatic but unsuspected overt thyroid dysfunction. The yield is highest for women older than 50 years of age: In this group, 1 in 71 women screened could benefit from relief of symptoms. Evidence of the efficacy of treatment for subclinical thyroid dysfunction is inconclusive. Even though treatment for subclinical thyroid dysfunction is controversial, office-based screening to detect overt thyroid dysfunction may be indicated in women older than 50 years of age. Large randomized trials are needed to determine the likelihood that treatment will improve quality of life in otherwise healthy patients who have mildly elevated TSH levels.
Article
Overt hypothyroidism has been found to be associated with cardiovascular disease. Whether subclinical hypothyroidism and thyroid autoimmunity are also risk factors for cardiovascular disease is controversial. To investigate whether subclinical hypothyroidism and thyroid autoimmunity are associated with aortic atherosclerosis and myocardial infarction in postmenopausal women. Population-based cross-sectional study. A district of Rotterdam, The Netherlands. Random sample of 1149 women (mean age +/- SD, 69.0 +/- 7.5 years) participating in the Rotterdam Study. Data on thyroid status, aortic atherosclerosis, and history of myocardial infarction were obtained at baseline. Subclinical hypothyroidism was defined as an elevated thyroid-stimulating hormone level (>4.0 mU/L) and a normal serum free thyroxine level (11 to 25 pmol/L [0.9 to 1.9 ng/dL]). In tests for antibodies to thyroid peroxidase, a serum level greater than 10 IU/mL was considered a positive result. Subclinical hypothyroidism was present in 10.8% of participants and was associated with a greater age-adjusted prevalence of aortic atherosclerosis (odds ratio, 1.7 [95% CI, 1.1 to 2.6]) and myocardial infarction (odds ratio, 2.3 [CI, 1.3 to 4.0]). Additional adjustment for body mass index, total and high-density lipoprotein cholesterol level, blood pressure, and smoking status, as well as exclusion of women who took beta-blockers, did not affect these estimates. Associations were slightly stronger in women who had subclinical hypothyroidism and antibodies to thyroid peroxidase (odds ratio for aortic atherosclerosis, 1.9 [CI, 1.1 to 3.6]; odds ratio for myocardial infarction, 3.1 [CI, 1.5 to 6.3]). No association was found between thyroid autoimmunity itself and cardiovascular disease. The population attributable risk percentage for subclinical hypothyroidism associated with myocardial infarction was within the range of that for known major risk factors for cardiovascular disease. Subclinical hypothyroidism is a strong indicator of risk for atherosclerosis and myocardial infarction in elderly women.
Article
The prevalence of abnormal thyroid function in the United States and the significance of thyroid dysfunction remain controversial. Systemic effects of abnormal thyroid function have not been fully delineated, particularly in cases of mild thyroid failure. Also, the relationship between traditional hypothyroid symptoms and biochemical thyroid function is unclear. To determine the prevalence of abnormal thyroid function and the relationship between (1) abnormal thyroid function and lipid levels and (2) abnormal thyroid function and symptoms using modern and sensitive thyroid tests. Cross-sectional study. Participants in a statewide health fair in Colorado, 1995 (N = 25 862). Serum thyrotropin (thyroid-stimulating hormone [TSH]) and total thyroxine (T4) concentrations, serum lipid levels, and responses to a hypothyroid symptoms questionnaire. The prevalence of elevated TSH levels (normal range, 0.3-5.1 mIU/L) in this population was 9.5%, and the prevalence of decreased TSH levels was 2.2%. Forty percent of patients taking thyroid medications had abnormal TSH levels. Lipid levels increased in a graded fashion as thyroid function declined. Also, the mean total cholesterol and low-density lipoprotein cholesterol levels of subjects with TSH values between 5.1 and 10 mIU/L were significantly greater than the corresponding mean lipid levels in euthyroid subjects. Symptoms were reported more often in hypothyroid vs euthyroid individuals, but individual symptom sensitivities were low. The prevalence of abnormal biochemical thyroid function reported here is substantial and confirms previous reports in smaller populations. Among patients taking thyroid medication, only 60% were within the normal range of TSH. Modest elevations of TSH corresponded to changes in lipid levels that may affect cardiovascular health. Individual symptoms were not very sensitive, but patients who report multiple thyroid symptoms warrant serum thyroid testing. These results confirm that thyroid dysfunction is common, may often go undetected, and may be associated with adverse health outcomes that can be avoided by serum TSH measurement.
Article
We report a 43 years old female, admitted due to fatigability, asthenia and diffuse abdominal pain. On admission, obesity, slowness of thinking, bradycardia, distention of jugular veins and ascites were observed on physical examination. Laboratory showed undetectable thyroid hormone levels, a chest X ray showed bilateral pleural effusion and an enlarged heart. An echocardiography showed a massive pericardial effusion with collapse of the right atrium and dilatation of both caval veins. A pericardial tap was performed, draining 350 ml. Thyroid hormone substitution was started and after 12 months of follow up, the heart size decreased and a control echocardiogram showed a minimal pericardial effusion.