701
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Correia N, Mullally S, Cooke G, Tun TK, Phelan N, Feeney J, Fitzgibbon M, Boran G, O'Mara S, Gibney J. Evidence for a specific defect in hippocampal memory in overt and subclinical hypothyroidism. J Clin Endocrinol Metab 2009; 94:3789-97. [PMID: 19584178 DOI: 10.1210/jc.2008-2702] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Declarative memory largely depends upon normal functioning temporal lobes (hippocampal complex) and prefrontal cortex. Animal studies suggest abnormal hippocampal function in hypothyroidism. OBJECTIVE The aim of the study was to assess declarative memory in overt and subclinical (SCH) hypothyroid patients before and after l-T(4) (LT4) replacement and in matched normal subjects. DESIGN AND SETTING A prospective, open-labeled interventional study was conducted at a teaching hospital. PARTICIPANTS AND INTERVENTION Hypothyroid (n = 21) and SCH (n = 17) patients underwent neuropsychological tests at baseline and 3 and 6 months after LT4 replacement. Normal subjects were studied at the same time-points. MAIN OUTCOME Tests of spatial, verbal, associative, and working memory; attention; and response inhibition and the Hospital Anxiety and Depression Scale were administered. RESULTS Baseline deficits in spatial, associative, and verbal memory, which rely upon the integrity of the hippocampal and frontal areas, were identified in patients with overt hypothyroidism. Spatial and verbal memory were impaired in SCH patients (P < 0.05). TSH levels correlated negatively (P < 0.05) with these deficits. After LT4 replacement, verbal memory normalized. Spatial memory normalized in the SCH group but remained impaired in the hypothyroid group. Associative memory deficits persisted in the overt hypothyroid group. Hospital Anxiety and Depression Scale scores did not correlate with cognitive function. Measures of attention and response inhibition did not differ from control subjects. CONCLUSION Cognitive impairment occurs in SCH and more markedly in overt hypothyroidism. These impairments appear predominantly mnemonic in nature, suggesting that the etiology is not indicative of general cognitive slowing. We propose that these deficits may reflect an underlying disruption of normal hippocampal function and/or connectivity.
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Affiliation(s)
- Neuman Correia
- Department of Endocrinology and Diabetes, Adelaide and Meath Hospital, incorporating the National Children's Hospital, Tallaght, Dublin 24, Ireland
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702
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Hari Kumar KVS, Verma A, Muthukrishnan J, Modi KD. Obesity and thyrotropinemia. Indian J Pediatr 2009; 76:933-5. [PMID: 19475347 DOI: 10.1007/s12098-009-0153-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Accepted: 08/20/2008] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To study the relation between body mass index (BMI) and TSH in euthyroid and subclinical hypothyroid obese children and compared serum TSH level among obese and overweight children. METHODS Fifty consecutive children (aged 2-18 yr) presenting for obesity were studied. All cases with TSH > 10, low T3/T4, organic and syndromic obesity were excluded. Patients were divided into Group 1: Overweight (n=20) (BMI between 85(th) to 95(th) centile) and Group 2: Obesity (n=30) (BMI > 95(th) centile). Fisher's exact test, Mann-Whitney U test and Pearson's correlation were used for statistical analysis. P value < 0.05 was considered significant. RESULTS Elevated TSH level (between 4.5-10 mIU/L) with normal T3, T4 was seen in 4/20 overweight and 9/30 of obese children (P=0.5219). The mean TSH was comparable in both the groups (3.22 +/- 3.1 mIU/L vs. 3.63 +/- 2.2 mIU/L, P=0.3491). Overall TSH showed no correlation with BMI (r= 0.0014, P=0.9924). CONCLUSION The preliminary data did not show any relation between severity of obesity and TSH level. Further large scale data from population are required to confirm these findings.
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Affiliation(s)
- K V S Hari Kumar
- Department of Endocrinology, MEDWIN Hospitals, Hyderabad, AP, India.
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703
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Romão R, Rubio IGS, Tomimori EK, Camargo RY, Knobel M, Medeiros-Neto G. High prevalence of side effects after recombinant human thyrotropin-stimulated radioiodine treatment with 30 mCi in patients with multinodular goiter and subclinical/clinical hyperthyroidism. Thyroid 2009; 19:945-51. [PMID: 19678745 DOI: 10.1089/thy.2008.0394] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Treatment of multinodular goiters (MNGs) is highly controversial. Radioiodine (RAI) therapy is a nonsurgical alternative for the elderly who decline surgery. Recently, recombinant human thyrotropin (rhTSH) has been used to augment RAI uptake and distribution. In this study, we determined the outcome of 30 mCi RAI preceded by rhTSH (0.1 mg) in euthyroid (EU) and hyperthyroid (subclinical/clinical) patients with large MNGs. METHODS This was a prospective cohort study. Forty-two patients (age, 43-80 years) with MNGs were treated with 30 mCi RAI after stimulation with 0.1 mg of rhTSH. Patients were divided into three groups, according to thyroid function: EU (n = 18), subclinically hyperthyroid (SC-H, n = 18), and clinically hyperthyroid (C-H, n = 6). All patients underwent a 90-day low-iodine diet before treatment, and those with clinical hyperthyroidism received methimazole 10 mg daily for 30 days. Serum TSH, free thyroxine (FT4), total triiodothyronine (TT3), and thyroglobulin were measured at baseline and at 24, 48, 72, 168 hours, and 1, 3, 6, 9, 12, 18, 24, and 36 months after therapy. Thyroid volume was assessed by computed tomography at baseline and every 6 months. RESULTS Patients had high iodine urinary excretion (308 +/- 108 microg I/L) at baseline. TSH levels at baseline were within the normal range (1.5 +/- 0.7 microU/mL) in the EU group and suppressed (<0.3 microU/mL) in the SC-H and C-H groups. After rhTSH, serum TSH peaked at 24 hours reaching 12.4 +/- 5.85 microU/mL. After RAI administration, patients in both hyperthyroid groups had a higher increase in FT4 and TT3 compared with those in the EU group (p < 0.001). Thyroglobulin levels increased equally in all three groups until day 7. Thyroid volume decreased significantly in all patients. Side effects were more common in the SC-H and C-H groups (31.4% and 60.4%, respectively) compared with EU patients (17.8%). Permanent hypothyroidism was more prevalent in the EU group (50%) compared with the SC-H (11%) and C-H (16.6%) groups. CONCLUSIONS Patients with MNG may have subclinical and clinical nonautoimmune iodine-induced hyperthyroidism. Despite a low-iodine diet and therapy with methimazole, hyperthyroid patients have a significantly higher increase in FT4 and TT3 levels after RAI ablation. This can lead to important side effects related mostly to the cardiac system. We strongly advise that patients with SC-H and C-H be adequately treated with methimazole and low-iodine diet aiming to normalize their hyperthyroid condition before rhTSH-stimulated treatment with RAI.
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Affiliation(s)
- Rossana Romão
- Thyroid Unit (LIM-25), Division of Endocrinology, University of São Paulo Medical School , Hospital das Clínicas, São Paulo, Brazil
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704
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Ross HA, den Heijer M, Hermus ARMM, Sweep FCGJ. Composite reference interval for thyroid-stimulating hormone and free thyroxine, comparison with common cutoff values, and reconsideration of subclinical thyroid disease. Clin Chem 2009; 55:2019-25. [PMID: 19713278 DOI: 10.1373/clinchem.2009.124560] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Examination of the 2-dimensional probability distribution of thyroid-stimulating hormone (TSH) and free thyroxine (FT(4)) shows that the widths of the TSH and FT(4) reference intervals derived from this bivariate distribution are mutually interdependent, an aspect commonly ignored when interpreting thyroid testing results with separate reference intervals for TSH and FT(4). We desired to establish and critically evaluate a composite reference interval for TSH and FT(4) to allow bivariate classification of biochemical thyroid conditions. METHODS FT(4) and TSH results of 871 healthy individuals [361 women and 510 men, 18-40 years old, without history of thyroid-related disease or medication, negative for anti-thyroid peroxidase (anti-TPO) antibody] were transformed to standard normal variables by logarithmic transformation with correction for skewness and subsequent normalization. We established a 95% reference interval of the distance of each FT(4)/TSH pair of values to the center of the 2-dimensional probability distribution. RESULTS The bivariate 95% reference interval is enclosed by a circular profile with radius 2.45 SD. By contrast, conventional reference intervals comprise a square with the boundaries of -1.96 and +1.96 SD for both FT(4) and TSH that enclose only 90% of all data. Compared with the +/-1.96 SD square, the bivariate reference interval classified 4% fewer of 3651 healthy individuals older than 40 years as subclinically hyperthyroid and 14% fewer of 712 anti-TPO-positive healthy individuals as subclinically hypothyroid. CONCLUSIONS Conventional application of separate cutoff values for FT(4) and TSH leads to overestimation of the incidence of subclinical thyroid disease. Application of a composite overall reference interval is recommended.
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Affiliation(s)
- H Alec Ross
- Department of Chemical Endocrinology and Department of Endocrinology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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705
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Baldini M, Colasanti A, Orsatti A, Airaghi L, Mauri MC, Cappellini MD. Neuropsychological functions and metabolic aspects in subclinical hypothyroidism: the effects of L-thyroxine. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:854-9. [PMID: 19389454 DOI: 10.1016/j.pnpbp.2009.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 04/02/2009] [Accepted: 04/10/2009] [Indexed: 10/20/2022]
Abstract
Thyroid hypofunction is a slowly progressing graded phenomenon [Vanderpump MP, Tunbridge WM, French JM, Appleton D, Bates D, Clark F, et al. The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham Survey. Clin Endocrinol (Oxf) 1995;43(1):55-68]; subclinical forms (SCH) often represent a laboratory diagnosis in apparently asymptomatic patients. In the absence of adequate parameters for thyroid hormone action in tissues, the level of TSH increase corresponding to negative effects remains unsettled. We studied a wide range of physiological processes in a strictly selected population of 38 female patients (56.4+/-12.6 years) with minor forms of SCH (TSH 6.6+/-1.8 mIU/L), after exclusion of neurological, psychiatric and somatic disorders or confounding conditions. The investigations, performed at admission and after 6 months of l-thyroxine (LT4) treatment, included metabolic evaluation, health status perception and an extensive battery of neuropsychological tests and psychological rating scales. Lipid metabolism improved after LT4 (total cholesterol: 231.9+/-49.6 mg/dl pre- vs 221.0+/-40.0 mg/dl post-treatment; LDL cholesterol: 183.1+/-62.9 vs 162.7+/-53.7 mg/dl; apolipoprotein A1: 183.5+/-64.5 vs 160.9+/-50.3 mg/dl; p<0.05 for all comparisons), while glucose metabolism was unchanged. Health status perception was favourably influenced by the treatment (total SF-36 score 97.8+/-18.4 pre- vs 108.5+/-14.8 post-, p<0.0001); in a matched control group with euthyroid goiter, tested to examine the effects of medical care in the absence of treatment, no significant differences were found in the SF-36 scores at admission and after 6 months (109.3+/-15.1 vs 109+/-14.2, p=0.9). Attention performance improved after LT4; HRSD and HRSA scores did not significantly change, but negative correlations were found between FT3 levels and affective scores at admission, and between the post-treatment changes of affective scores and of FT3. In our study subtle disturbances of health status perception, attention and lipid metabolism associated to SCH of mildest degrees were reverted by LT4 replacement, reinforcing reports of unfavourable consequences of marginal thyroid disease.
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Affiliation(s)
- Marina Baldini
- U.O. Medicina Interna 1 A, Padiglione Granelli, IRCCS Fondazione Policlinico, MA., R.E., via Francesco Sforza 35, 20122, Milan, Italy.
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706
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Park YJ, Lee EJ, Lee YJ, Choi SH, Park JH, Lee SB, Lim S, Lee WW, Jang HC, Cho BY, Woo JI, Kim KW. Subclinical hypothyroidism (SCH) is not associated with metabolic derangement, cognitive impairment, depression or poor quality of life (QoL) in elderly subjects. Arch Gerontol Geriatr 2009; 50:e68-73. [PMID: 19545916 DOI: 10.1016/j.archger.2009.05.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 05/24/2009] [Accepted: 05/26/2009] [Indexed: 10/20/2022]
Abstract
The objective of this study was to examine the relationship between SCH and metabolic and neuropsychiatric derangements in Korean elderly subjects. Nine hundred and eighteen euthyroid and SCH subjects aged 65 years and older were enrolled in the present study. We compared anthropometric (age, sex, blood pressure, body mass index=BMI, body fat contents=BF, waist circumference=WC and hip circumference=HC), laboratory (glucose and lipid profile, renal and liver functions, and C-reactive protein=CRP levels), and neuropsychiatric (neuropsychological function, mood, and QoL) parameters of SCH subjects with those of euthyroid subjects. Associated metabolic disorders of the subjects were also compared between the euthyroid and SCH groups. We could not observe any differences between the SCH group and the euthyroid group with regards to metabolic parameters as well as neuropsychiatric parameters. These findings may suggest that SCH does not appear to be associated with metabolic and neuropsychiatric derangement in elderly subjects.
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Affiliation(s)
- Young Joo Park
- Department of Internal Medicine, Seoul National University of College of Medicine, 28 Yeongeon-dong Jongno-gu, Seoul 110-744, Republic of Korea
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707
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Di Bello V, Talini E, Donne MGD, Aghini-Lombardi F, Monzani F, La Carrubba S, Antonini-Canterin F, Dini FL, Di Salvo G, Carerj S, Marzilli M. New Echocardiographic Techniques in the Evaluation of Left Ventricular Mechanics in Subclinical Thyroid Dysfunction. Echocardiography 2009; 26:711-9. [DOI: 10.1111/j.1540-8175.2008.00875.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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708
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Goldman S, McCarren M, Morkin E, Ladenson PW, Edson R, Warren S, Ohm J, Thai H, Churby L, Barnhill J, O'Brien T, Anand I, Warner A, Hattler B, Dunlap M, Erikson J, Shih MC, Lavori P. DITPA (3,5-Diiodothyropropionic Acid), a thyroid hormone analog to treat heart failure: phase II trial veterans affairs cooperative study. Circulation 2009; 119:3093-100. [PMID: 19506112 DOI: 10.1161/circulationaha.108.834424] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND In animal studies and a pilot trial in patients with congestive heart failure, the thyroid hormone analog 3,5 diiodothyropropionic acid (DITPA) had beneficial hemodynamic effects. METHODS AND RESULTS This was a phase II multicenter, randomized, placebo-controlled, double-blind trial of New York Heart Association class II to IV congestive heart failure patients randomized (2:1) to DITPA or placebo and treated for 6 months. The study enrolled 86 patients (n=57 to DITPA, n=29 to placebo). The primary objective was to assess the effect of DITPA on a composite congestive heart failure end point that classifies patients as improved, worsened, or unchanged based on symptom changes and morbidity/mortality. DITPA was poorly tolerated, which obscured the interpretation of congestive heart failure-specific effects. Fatigue and gastrointestinal complaints, in particular, were more frequent in the DITPA group. DITPA increased cardiac index (by 18%) and decreased systemic vascular resistance (by 11%), serum cholesterol (-20%), low-density lipoprotein cholesterol (-30%), and body weight (-11 lb). Thyroid-stimulating hormone was suppressed in patients given DITPA, which reflects its thyromimetic effect; however, no symptoms or signs of potential hypothyroidism or thyrotoxicosis were seen. CONCLUSIONS DITPA improved some hemodynamic and metabolic parameters, but there was no evidence for symptomatic benefit in congestive heart failure.
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Affiliation(s)
- Steven Goldman
- Cardiology Section (1-111C), Southern Arizona VA Health Care System, 3601 S 6th Ave, Tucson, AZ 85723, USA.
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709
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Park YJ, Yoon JW, Kim KI, Lee YJ, Kim KW, Choi SH, Lim S, Choi DJ, Park KH, Choh JH, Jang HC, Kim SY, Cho BY, Lim C. Subclinical Hypothyroidism Might Increase the Risk of Transient Atrial Fibrillation After Coronary Artery Bypass Grafting. Ann Thorac Surg 2009; 87:1846-52. [DOI: 10.1016/j.athoracsur.2009.03.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 03/10/2009] [Accepted: 03/12/2009] [Indexed: 10/20/2022]
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710
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Abstract
Iodine deficiency has multiple adverse effects in humans, termed iodine deficiency disorders, due to inadequate thyroid hormone production. Globally, it is estimated that 2 billion individuals have an insufficient iodine intake, and South Asia and sub-Saharan Africa are particularly affected. However, about 50% of Europe remains mildly iodine deficient, and iodine intakes in other industrialized countries, including the United States and Australia, have fallen in recent years. Iodine deficiency during pregnancy and infancy may impair growth and neurodevelopment of the offspring and increase infant mortality. Deficiency during childhood reduces somatic growth and cognitive and motor function. Assessment methods include urinary iodine concentration, goiter, newborn TSH, and blood thyroglobulin. But assessment of iodine status in pregnancy is difficult, and it remains unclear whether iodine intakes are sufficient in this group, leading to calls for iodine supplementation during pregnancy in several industrialized countries. In most countries, the best strategy to control iodine deficiency in populations is carefully monitored universal salt iodization, one of the most cost-effective ways to contribute to economic and social development. Achieving optimal iodine intakes from iodized salt (in the range of 150-250 microg/d for adults) may minimize the amount of thyroid dysfunction in populations. Ensuring adequate iodine status during parenteral nutrition has become important, particularly in preterm infants, as the use of povidone-iodine disinfectants has declined. Introduction of iodized salt to regions of chronic iodine deficiency may transiently increase the incidence of thyroid disorders, but overall, the relatively small risks of iodine excess are far outweighed by the substantial risks of iodine deficiency.
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Affiliation(s)
- Michael B Zimmermann
- Laboratory for Human Nutrition, Swiss Federal Institute of Technology Zürich, Schmelzbergstrasse 7, LFV E19, CH-8092 Zürich, Switzerland.
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711
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Boucai L, Surks MI. Reference limits of serum TSH and free T4 are significantly influenced by race and age in an urban outpatient medical practice. Clin Endocrinol (Oxf) 2009; 70:788-93. [PMID: 18727705 DOI: 10.1111/j.1365-2265.2008.03390.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE The suitability of TSH reference limits derived from national databases to outpatient practices has not been established. We aimed to determine whether race and age influence the distribution of TSH and free T4 (fT4). DESIGN A cross-sectional study of an urban outpatient medical practice. PARTICIPANTS Patients (n = 22,116) without clinical evidence of thyroid disease or use of thyroid-specific medications. MEASUREMENTS Comparison of TSH and fT4 distributions in specific racial and age groups including blacks, whites and Hispanics. RESULTS TSH was distributed at higher concentrations, without skew, in whites compared to blacks (median, 1.54 mIU/l vs. 1.18 mIU/l, P < 0.001) and in old (>80 years old) compared to young (20-29 years old) (median, 1.61 mIU/l vs. 1.13 mIU/l, P < 0.001). In all patients, blacks and whites, 3%, 8% and 5%, respectively, of those aged > 80 years were misclassified as having high TSH compared to those aged 20-29 years (P < 0.001). Using TSH limits from national databases resulted in significant misclassification of patients with raised or lowered TSH. Mean fT4 was significantly lower in blacks than whites (17.5 +/- 4.38 pmol/l vs. 18.3 +/- 3.99 pmol/l, P < 0.001), did not differ between young and old, but decreased progressively (average 7%) as TSH increased to > 4.5 mIU/l. CONCLUSIONS Reference limits for TSH differ between races and with age. Use of race- and age-specific reference limits decreases misclassification of patients with lowered or raised TSH in an urban practice. The unique fT4:TSH relationships of blacks and whites may be genetically determined. The implications of the small decrement in fT4 as TSH increases remain to be explored.
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Affiliation(s)
- Laura Boucai
- Department of Medicine, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY 10467, USA.
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712
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Lazar L, Frumkin RBD, Battat E, Lebenthal Y, Phillip M, Meyerovitch J. Natural history of thyroid function tests over 5 years in a large pediatric cohort. J Clin Endocrinol Metab 2009; 94:1678-82. [PMID: 19240148 DOI: 10.1210/jc.2008-2615] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Because clinical manifestations of thyroid disorders are variable and subtle in children and adolescents, thyroid function tests are often repeated in patients with nonspecific symptoms. OBJECTIVES The objective of the study was to determine the natural history of initial abnormal TSH and define populations at greater risk for developing a subsequent thyroid dysfunction. METHODS A total of 121,052 of 1.043 million outpatients aged 0.5-16 yr insured by the Clalit Health Medical Organization had a TSH determination in 2002 and follow-up to 2007. Extracted from the Clalit Health Medical Organization database were their demographic data, referral diagnoses, and laboratory results (TSH, free T(4), thyroid antibodies). Excluded were patients with overt hypothyroidism or hyperthyroidism on initial testing. RESULTS Results of 96.5% of initial serum TSH concentrations were normal (0.35-5.5 mIU/liter), 0.2% were low (<0.35 mIU/liter), 2.9% elevated (>5.5 to <or=10 mIU/liter), and 0.4% highly elevated (>10 mIU/liter). The frequency of TSH testing increased with age and female gender. During follow-up, repeated (two to more than four) TSH tests were performed in 45.7% of the patients. In the second TSH determination, normal TSH was documented in 40, 73.6, and 78.9% of those whose initial serum TSH was highly elevated, elevated, and low, respectively, and in 97% of those with normal initial TSH. Predictive factors for a sustained highly elevated TSH were initial TSH greater than 7.5 mIU/liter (P = 0.014) and female gender (P = 0.047). CONCLUSIONS In the pediatric population, initial normal or slightly elevated TSH levels are likely to remain normal or spontaneously normalize without treatment. Patients with initial levels greater than 7.5 mIU/liter, particularly girls, are at a greater risk for sustained abnormal TSH levels.
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Affiliation(s)
- Liora Lazar
- The Jesse Z. and Sara Lea Shafer Institute for Endocrinology and Diabetes, National Center for Childhood Diabetes, Schneider Children's Medical Center of Israel, Petah Tikva 49202, Israel
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713
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Lucas Martín AM. [Postpartum thyroiditis: Must we do sreenning?]. Med Clin (Barc) 2009; 132:585-6. [PMID: 19375120 DOI: 10.1016/j.medcli.2009.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 01/05/2009] [Indexed: 10/20/2022]
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714
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Atzmon G, Barzilai N, Hollowell JG, Surks MI, Gabriely I. Extreme longevity is associated with increased serum thyrotropin. J Clin Endocrinol Metab 2009; 94:1251-4. [PMID: 19158193 PMCID: PMC2682478 DOI: 10.1210/jc.2008-2325] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CONTEXT The distribution of serum TSH shifts progressively to higher concentrations with age. OBJECTIVE The aim of the study was to determine whether the population shift in TSH distribution to higher concentrations with aging extends to people of exceptional longevity, namely centenarians, and to assess the relationship between concentrations of TSH and free T(4) (FT4). DESIGN/SETTING/PATIENTS We analyzed TSH, FT4, and TSH frequency distribution curves in thyroid disease-free Ashkenazi Jews with exceptional longevity (centenarians; median age, 98 yr), in younger Ashkenazi controls (median age, 72 yr), and in a population of thyroid disease-free individuals (median age, 68 yr) from the U.S. National Health and Nutrition Examination Survey 1998-2002 (NHANES controls). RESULTS Serum TSH was significantly higher in centenarians [1.97 (0.42-7.15) mIU/liter] than in Ashkenazi controls [1.55 (0.46-4.55) mIU/liter] and NHANES controls [1.61 (0.39-6.29) mIU/liter] (median, 2.5 and 97.5 centiles) (P < 0.001). The TSH frequency distribution curve of centenarians was relatively similar in shape to controls but shifted significantly to higher TSH, including TSH concentration at peak frequency. The TSH distribution curve of the NHANES control group was superimposable to and not significantly different from the Ashkenazi controls. FT4 was similar in centenarians and Ashkenazi controls, and there was a significant inverse correlation between FT4 and TSH in both groups. CONCLUSIONS The TSH population shifts to higher concentrations with age appear to be a continuum that extends even to people with exceptional longevity. The inverse correlation between TSH and FT4 in our populations suggests that changes in negative feedback may contribute to exceptional longevity.
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Affiliation(s)
- Gil Atzmon
- Department of MedicineDivision of Endocrinology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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715
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Ventura T, Manor R, Aflalo ED, Weil S, Raviv S, Glazer L, Sagi A. Temporal silencing of an androgenic gland-specific insulin-like gene affecting phenotypical gender differences and spermatogenesis. Endocrinology 2009; 150:1278-86. [PMID: 18988670 DOI: 10.1210/en.2008-0906] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Androgenic glands (AGs) of the freshwater prawn Macrobrachium rosenbergii were subjected to endocrine manipulation, causing them to hypertrophy. Transcripts from these glands were used in the construction of an AG cDNA subtractive library. Screening of the library revealed an AG-specific gene, termed the M. rosenbergii insulin-like AG (Mr-IAG) gene. The cDNA of this gene was then cloned and fully sequenced. The cysteine backbone of the predicted mature Mr-IAG peptide (B and A chains) showed high similarity to that of other crustacean AG-specific insulin-like peptides. In vivo silencing of the gene, by injecting the prawns with Mr-IAG double-stranded RNA, temporarily prevented the regeneration of male secondary sexual characteristics, accompanied by a lag in molt and a reduction in growth parameters, which are typically higher in males of the species. In terms of reproductive parameters, silencing of Mr-IAG led to the arrest of testicular spermatogenesis and of spermatophore development in the terminal ampullae of the sperm duct, accompanied by hypertrophy and hyperplasia of the AGs. This study constitutes the first report of the silencing of a gene expressed specifically in the AG, which caused a transient adverse effect on male phenotypical gender differences and spermatogenesis.
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Affiliation(s)
- Tomer Ventura
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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716
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Abstract
Subclinical and overt hyperthyroidism have been associated with various negative clinical outcomes as for example an increased risk of atrial fibrillation or increased cardiovascular mortality, especially in old age. In order to avoid hyperthyroidism it is strongly recommended not to start any iodine containing drug therapy or to avoid application of contrast agents unless the patient presents with an unremarkable clinical course. TSH suppressive therapy for the treatment of endemic goiter or differentiated low risk thyroid carcinoma is unnecessary, since it favours the development of subclinical hyperthyroidism. Overt hyperthyroidism is treated with antithyroid drugs and/or radioiodine therapy or surgery according to the underlying disease (toxic nodular goiter, Graves' disease).
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717
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Goichot B, Sapin R, Schlienger JL. Subclinical hyperthyroidism: considerations in defining the lower limit of the thyrotropin reference interval. Clin Chem 2009; 55:420-4. [PMID: 19147733 DOI: 10.1373/clinchem.2008.110627] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Although numerous reports have discussed the upper limit of the thyrotropin (TSH) reference interval, none have dealt with the lower limit. Recent recommendations regarding subclinical thyroid dysfunction give different advice about its management, depending on whether the TSH concentration is <0.1 mIU/L or 0.1-0.4 mIU/L. CONTENT We review key studies that have investigated the links between low TSH concentrations, cardiovascular morbidity, and mortality, with a focus on the TSH measurement threshold and assay type. SUMMARY Despite numerous consensus guidelines and publications of expert opinion, the management of subclinical hyperthyroidism remains largely intuitive and "nonevidence-based." The primary reason for this unsatisfactory situation is the absence of clinical-intervention trials. Important aspects that remain to be addressed are the influence of the method used to measure TSH, the definition of "normality," and the lack of evidence to base the grading of cardiovascular risk on the degree of TSH suppression. A risk-based approach should be adopted to determine the thresholds that would justify interventions. Such considerations assume, of course, that proof will emerge from ongoing clinical trials to support the medical utility of treating subclinical hyperthyroidism.
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Affiliation(s)
- Bernard Goichot
- Service de Médecine Interne et Nutrition, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
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718
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Langevin R, Langevin M, Curnoe S, Bain J. The prevalence of thyroid disorders among sexual and violent offenders and their co‐occurrence with psychological symptoms. Int J Prison Health 2009; 5:25-38. [DOI: 10.1080/17449200802692086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The prevalence of thyroid abnormalities among 831 sexual, violent, and non‐violent non‐sex offenders was found to be greater than found in the general population. Thyroid abnormalities were most common among violent offenders and among sex offenders who victimized children. Thyroid disorders were associated with psychotic diagnoses, delusions, mania, suicidal thoughts, and showed a trend to more suicide attempts. These disorders were undiagnosed in 49.1% of the cases prior to the present clinical assessment. Of these, 59.3% faced their first criminal charges, and the undiagnosed thyroid abnormalities may be important in the offenders’ treatment and may be possible legal mitigating factors in some offenses. Results indicate that a routine endocrine evaluation with blood tests would be a valuable addition to the assessment of violent and sexual offenders.
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719
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Rosário PWS, Bessa B, Valadão MMA, Purisch S. Natural history of mild subclinical hypothyroidism: prognostic value of ultrasound. Thyroid 2009; 19:9-12. [PMID: 19021461 DOI: 10.1089/thy.2008.0221] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Clinical repercussions, progression to overt hypothyroidism, and treatment benefits have been well established in patients with subclinical hypothyroidism (SCH) and TSH >10 mIU/L. In contrast, these aspects of the disease are poorly understood in patients with even milder SCH as defined by TSH < or = 10 mIU/L and normal thyroid hormone levels. Therefore, we sought to evaluate the natural history of this milder form of SCH (TSH < or =10 mIU/L with normal thyroid hormone levels) in adult women patients. PATIENTS One hundred seventeen patients with TSH levels ranging from 5 to 10 mIU/L and normal free T4, without a previously known history of thyroid disease, were followed for a period of 3 years and had two consecutive assessments. RESULTS Sixty patients tested positive for antithyroperoxidase antibodies (TPOAb) and 36 were TPOAb negative but had diffuse hypoechogenicity on thyroid ultrasound (US). Twenty-one patients were TPOAb negative and had normal US. During follow-up, 20.5% of the patients had spontaneous normalization of their TSH, 27.3% required replacement therapy with levothyroxine (L-T4) because of progression to overt hypothyroidism or persistence of serum TSH >10 mIU/L, and 52.1% continued to meet the criteria for mild SCH (persistence of TSH < or =10 mIU/L). If the patients were classified into two groups, one with positive TPOAb and/or US alteration and the other with testing negative for TPOAb and not having US alteration, the first group had a greater progression toward overt hypothyroidism (31.2% vs. 9.5%, respectively) and a lower rate of normalization of TSH (15.6% vs. 43% respectively). These rates were similar in TPOAb-positive patients and patients with negative TPOAb but with positive US. CONCLUSIONS Most patients with SCH and TSH < or = 10 mIU/L do not progress to overt hypothyroidism. The presence of chronic thyroiditis as demonstrated by US increases the evolution of SH to overt hypothyroidism or more severe SCH and thus the need for L-T4 treatment. US findings are important in determining the prognosis of mild SCH.
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Affiliation(s)
- Pedro W S Rosário
- Department of Thyroid, Endocrinology Service , Santa Casa de Belo Horizonte, Minas Gerais, Brazil .
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720
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Abstract
Subclinical hypothyroidism (SCH), also called mild thyroid failure, is diagnosed when peripheral thyroid hormone levels are within normal reference laboratory range but serum thyroid-stimulating hormone (TSH) levels are mildly elevated. This condition occurs in 3% to 8% of the general population. It is more common in women than men, and its prevalence increases with age. Of patients with SCH, 80% have a serum TSH of less than 10 mIU/L. The most important implication of SCH is high likelihood of progression to clinical hypothyroidism. The possibility that it is a cardiovascular risk factor has been a subject of debate. Large-scale randomized studies are needed for evidence-based recommendations regarding screening for mild thyroid failure and levothyroxine therapy for this condition. Currently, the practical approach is routine levothyroxine therapy for persons with a persistent serum TSH of more than 10.0 mIU/L and individualized therapy for those with a TSH of less than 10.0 mIU/L.
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Affiliation(s)
- Vahab Fatourechi
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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721
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Abstract
Subclinical hypothyroidism (SCH), also called mild thyroid failure, is diagnosed when peripheral thyroid hormone levels are within normal reference laboratory range but serum thyroid-stimulating hormone (TSH) levels are mildly elevated. This condition occurs in 3% to 8% of the general population. It is more common in women than men, and its prevalence increases with age. Of patients with SCH, 80% have a serum TSH of less than 10 mIU/L. The most important implication of SCH is high likelihood of progression to clinical hypothyroidism. The possibility that it is a cardiovascular risk factor has been a subject of debate. Large-scale randomized studies are needed for evidence-based recommendations regarding screening for mild thyroid failure and levothyroxine therapy for this condition. Currently, the practical approach is routine levothyroxine therapy for persons with a persistent serum TSH of more than 10.0 mIU/L and individualized therapy for those with a TSH of less than 10.0 mIU/L.
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Affiliation(s)
- Vahab Fatourechi
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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722
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Royland JE, Parker JS, Gilbert ME. A genomic analysis of subclinical hypothyroidism in hippocampus and neocortex of the developing rat brain. J Neuroendocrinol 2008; 20:1319-38. [PMID: 19094080 DOI: 10.1111/j.1365-2826.2008.01793.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Hypothyroidism during pregnancy and the early postnatal period has severe neurological consequences for the developing offspring. The impact of milder degrees of perturbation of the thyroid axis as encompassed in conditions of subclinical hypothyroidism and hypothyroxinemia, however, has not been established. The present investigation examined the effects of graded levels of hypothyroidism, from subclinical to severe, on global gene expression in the developing rodent brain. Thyroid hormone insufficiency was induced by administration of propylthiouracil (PTU) to pregnant rats via drinking water from gestational day 6 until sacrifice of pups prior to weaning. In the first study a specialised microarray, the Affymetrix Rat Neurobiology array RN_U34, was used to contrast gene expression in the hippocampus of animals exposed to 0 or 10 ppm (10 mg/l) PTU, a treatment producing severe hypothyroidism. In the second study, a more complete genome array (Affymetrix Rat 230A) was used to compare gene expression in the neocortex and hippocampus of postnatal day (PN) 14 animals experiencing graded degrees of thyroid hormone insufficiency induced by delivery of 0, 1, 2 or 3 ppm PTU to the dam. Dose-dependent up- and down-regulation were observed for gene transcripts known to play critical roles in brain development and brain function. Expression levels of a subset of approximately 25 genes in each brain region were altered at a dose of PTU (1 ppm) that induced mild hypothyroxinemia in dams and pups. These data indicate that genes driving important developmental processes are sensitive to relatively modest perturbations of the thyroid axis, and that the level of gene expression is related to the degree of hormone reduction. Altered patterns of gene expression during critical windows of brain development indicate that thyroid disease must be viewed as a continuum and that conditions typically considered 'subclinical' may induce structural and functional abnormalities in the developing central nervous system.
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Affiliation(s)
- J E Royland
- Neurotoxicology Division, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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723
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Bibliography. Current world literature. Obesity and nutrition. Curr Opin Endocrinol Diabetes Obes 2008; 15:470-5. [PMID: 18769222 DOI: 10.1097/med.0b013e328311f3cb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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724
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Abstract
PURPOSE OF REVIEW The brain is an important target organ for thyroid hormone, and alterations in mood and cognition may occur with thyroid dysfunction. Recent advances in the field of cognitive neurosciences have allowed more sensitive and focused testing of cognitive domains in patients with altered thyroid function. RECENT FINDINGS Based on recent population-based studies, there do not appear to be major deficits in cognitive functioning in overt or subclinical thyroid disease. However, interventional and functional imaging studies suggest that subtle deficits in specific cognitive domains probably do exist. The most commonly affected domains are working memory and executive function. Also present are alterations in mood, manifested by increased rates of depressive and anxiety symptoms. SUMMARY Patients with overt or subclinical thyroid dysfunction commonly complain of decrements in cognitive function, but studies suggest that such decrements are most likely to be minor or not related to the thyroid dysfunction. More common are mood alterations, which often improve with treatment.
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Affiliation(s)
- Mary H Samuels
- Oregon Health & Science University, Portland, Oregon 97239, USA.
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725
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Association of thyroid function with arterial pressure in normotensive and hypertensive euthyroid individuals: A cross-sectional study. Thyroid Res 2008; 1:3. [PMID: 19014646 PMCID: PMC2583982 DOI: 10.1186/1756-6614-1-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 09/29/2008] [Indexed: 11/24/2022] Open
Abstract
Background Overt hypothyroidism has been associated with arterial hypertension and increased arterial stiffness. Results in euthyroid individuals have been conflicting. We investigated associations of thyroid function with systolic (SAP) and diastolic (DAP) arterial pressure in euthyroid subjects. Methods 311 euthyroid individuals (185 women, mean age 43.9 ± 9) without a history of diabetes attending a preventive medicine program were examined. Subjects receiving thyroxine (10.6%) were excluded; 19.3% had hypertension, 43% had a family history for hypertension. TSH, fT4, thyroid autoantibodies, insulin, glucose were measured. The "fT4.TSH product", which has been suggested as a T4 resistance-index, was calculated. Results TSH range was 0.1–8, median 1.4 mU/L, fT4 range was 11.5–25.2 pmol/L, median 17.4. TSH and the "fT4.TSH product" were positively associated with DAP (p < 0.03, for both associations). In the subgroup of individuals with TSH levels 0.36–2.5 mU/L, both TSH and the "fT4.TSH product" were positively correlated with SAP (r = +0.133 p = 0.044, r = +0.152 p = 0.026) and DAP (r = +0.243 p < 0.001, r = +0.252 p < 0.001 respectively); in multivariate analysis the "fT4.TSH product" was a significant predictor of DAP independently of HOMA-IR and BMI (p < 0.001). Similar associations were found when only the non-hypertensive subjects were analysed (p = 0.004). Hypertensive patients had higher TSH levels (p = 0.02) and belonged more frequently to the subgroup with TSH > 2 mU/L (35.3% vs 21.3%, p = 0.045). Conclusion In euthyroid individuals the association of thyroid function with diastolic arterial pressure remains significant even when a stricter "normal range" for TSH levels is considered. The "freeT4.TSH" product appears to be an even stronger predictor of DAP, independently of HOMA insulin resistance index and obesity.
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726
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Mazokopakis EE, Karefilakis CM, Tsartsalis AN, Milkas AN, Starakis IK. Exemestane-induced subclinical hypothyroidism : a case report. Clin Drug Investig 2008; 28:669-71. [PMID: 18783305 DOI: 10.2165/00044011-200828100-00007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Several conditions and drugs induce subclinical hypothyroidism. We report the first case of subclinical hypothyroidism in a 65-year-old woman with breast cancer receiving therapy with the third-generation aromatase inhibitor exemestane 25 mg/day for 2 months. The patient presented with complaints of increasing fatigue and weakness since being commenced on exemestane and was taking no other drugs. There was no past history or family history of thyroid disease. Thyroid function tests prior to breast cancer surgery were normal. Detailed clinical examination and laboratory tests to determine the cause of the patient's increasing fatigue and weakness revealed only subclinical hypothyroidism, that is, an elevated level of thyroid-stimulating hormone (thyrotropin, TSH) only. Ultrasonography revealed a normal thyroid gland. Based on a diagnosis of symptomatic subclinical hypothyroidism, the patient was commenced on levothyroxine sodium 50 microg/day and exemestane was withdrawn. Thyroid dysfunction was restored 4 months after her admission with a significant improvement in symptoms. Levothyroxine sodium was withdrawn 6 months later and no recurrence of thyroid dysfunction occurred during a 1-year follow-up. We believe that the increasing fatigue and weakness in our patient might have been associated either with subclinical hypothyroidism or with administration of exemestane (a known adverse effect of the drug) or both. Further studies are required to investigate how exemestane influences thyroid function.
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Affiliation(s)
- Elias E Mazokopakis
- Department of Internal Medicine, Naval Hospital of Crete, Chania, Crete, Greece.
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727
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Chonchol M, Lippi G, Salvagno G, Zoppini G, Muggeo M, Targher G. Prevalence of subclinical hypothyroidism in patients with chronic kidney disease. Clin J Am Soc Nephrol 2008; 3:1296-300. [PMID: 18550654 PMCID: PMC2518789 DOI: 10.2215/cjn.00800208] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Accepted: 04/27/2008] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Subclinical primary hypothyroidism is highly prevalent in the general population, especially in the elderly. However, the prevalence of subclinical primary hypothyroidism in persons with chronic kidney disease (CKD) not requiring chronic dialysis is not well defined. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS Cross-sectional data from 3089 adult outpatients, who were consecutively referred by general practitioners for routine blood testing over the last two years, were analyzed. Glomerular filtration rate (GFR) was estimated by the abbreviated Modification of Diet in Renal Disease equation. Multivariable logistic regression was used to evaluate the independent association between prevalent subclinical primary hypothyroidism and estimated GFR. RESULTS Among 3089 adult participants, 293 (9.5%) had subclinical primary hypothyroidism and 277 (9%) had an estimated GFR <60 ml/min per 1.73 m(2). The prevalence of subclinical primary hypothyroidism increased from 7% at an estimated GFR >or=90 ml/min per 1.73 m(2) to 17.9% at an estimated GFR <60 ml/min per 1.73 m(2) (P < 0.0001 for trend). Compared with participants with an estimated GFR >or=60 ml/min per 1.73 m(2), those with estimated GFR <60 ml/min per 1.73 m(2) had an increased odds of subclinical primary hypothyroidism after adjusting for age, gender, fasting plasma glucose, total cholesterol, and triglyceride concentrations. CONCLUSIONS These findings suggest that subclinical primary hypothyroidism is a relatively common condition ( approximately 18%) among persons with CKD not requiring chronic dialysis, and it is independently associated with progressively lower estimated GFR in a large cohort of unselected outpatient adults.
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Affiliation(s)
- Michel Chonchol
- Division of Renal Diseases and Hypertension, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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728
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Razvi S, Shakoor A, Vanderpump M, Weaver JU, Pearce SHS. The influence of age on the relationship between subclinical hypothyroidism and ischemic heart disease: a metaanalysis. J Clin Endocrinol Metab 2008; 93:2998-3007. [PMID: 18505765 DOI: 10.1210/jc.2008-0167] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CONTEXT Subclinical hypothyroidism (SCH) is a common condition that has been associated with ischemic heart disease (IHD) in some, but not all, studies. This may be due to differences in study design and the characteristics of participants. OBJECTIVE Our objective was to investigate whether age and gender influence IHD prevalence, incidence, and mortality in people with SCH. DATA SOURCES Computerized (PubMed, EMBASE, and Cochrane Library) and manual searches of the literature to May 2007, published in English, were performed. STUDY SELECTION Epidemiological studies that quantified thyroid status and IHD events in adults were performed. DATA EXTRACTION Two authors independently reviewed articles and abstracted data. Results were compared across two groups based on the minimum age of participants studied (younger than 65 yr and 65 yr or older). DATA SYNTHESIS There were 15 studies included for analysis with 2,531 SCH participants and 26,491 euthyroid individuals. IHD incidence and prevalence were higher in SCH subjects compared with euthyroid participants from studies including those younger than 65 yr, but not studies of subjects aged older than 65 yr [odds ratio (95% confidence interval)]: 1.57 (1.19-2.06) vs. 1.01 (0.87-1.18) and 1.68 (1.27-2.23) vs. 1.02 (0.85-1.22), respectively. Cardiovascular/all-cause mortality was also elevated in participants from the younger than 65-yr studies, but not from the studies of older people: odds ratio 1.37 (1.04-1.79) vs. 0.85 (0.56-1.29). Prevalent IHD was higher in SCH participants of both genders, although this was statistically significant only in women. CONCLUSIONS SCH is associated with increased IHD (both prevalence and incidence) and cardiovascular mortality only in subjects from younger populations. These data suggest that increased vascular risk may only be present in younger individuals with SCH.
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Affiliation(s)
- Salman Razvi
- Department of Endocrinology, Queen Elizabeth Hospital, Gateshead, NE9 6SX, United Kingdom.
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729
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730
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Franklyn JA. Should we treat subclinical hyperthyroidism? ACTA ACUST UNITED AC 2008; 4:550-1. [PMID: 18665124 DOI: 10.1038/ncpendmet0917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Accepted: 06/04/2008] [Indexed: 11/09/2022]
Affiliation(s)
- Jayne A Franklyn
- Institute ofBiomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham, UK.
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731
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Erdal M, Sahin M, Saglam K, Hasimi A, Uckaya G, Yarpuz MY, Taslipinar A, Gharib H, Kutlu M. Increased serum chitotriosidase activity following restoration of euthyroidism in patients with subclinical hypothyroidism. Intern Med 2008; 47:1309-14. [PMID: 18628578 DOI: 10.2169/internalmedicine.47.1013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE Whether to treat subclinical hypothyroidism (SH) remains controversial. Serum chitotriosidase activity, a marker of activated macrophages, predicts new cardiovascular events. Chitotriosidase activity (ChT) is a new cardiovascular risk marker and is independent of C-reactive protein. The purpose of this study was to determine ChT levels in SH and to examine the effect of levothyroxine replacement on ChT. SUBJECTS AND METHODS A cohort of 60 patients with subclinical hypothyroidism and 62 healthy controls were enrolled in this study. Serum total and LDL cholesterol, total homocysteine (t-Hyc), highly sensitive C-reactive protein (hsCRP) levels and serum ChT in patients with subclinical hypothyroidism at baseline and after achieving euthyroid state by levothyroxine were assessed. RESULTS Pretreatment levels of TSH (10.06+/-5.09 vs. 2.08+/-0.95 mIU/L, p<0.05), and free T4 (0.94+/-0.21 vs. 1.35+/-0.26 ng/dl, p<0.05) were significantly higher than controls while total cholesterol, LDL cholesterol, t-Hyc, ChT and hsCRP levels were not different. ChT levels significantly increased after replacement therapy (137.2+/-14.18 vs. 156.88+/-13.10 nmol/mL/h, p<0.05). T-Hyc and hsCRP levels were not significantly different after treatment with levothyroxine therapy even in this subgroup of patients. None of the other biochemical risk factors improved after euthyroidism in patients with SH with average dose of 85+/-30 mug/day when compared to pretreatment levels. CONCLUSION We conclude that clinical management of subclinical hypothyroidism does not decrease the serum hsCRP or t-Hyc levels but does increase the serum ChT levels. The clinical significance of this increment should be studied in further studies.
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Affiliation(s)
- Muhammed Erdal
- Department of Family Medicine Gulhane School of Medicine, Etlik, Ankara, Turkey
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