Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
1.
J Endocrinol Invest ; 47(4): 903-911, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37812282

RESUMEN

OBJECTIVE: Functional hypothalamic amenorrhea (FHA) is one of the foremost manifestations in anorexia nervosa (AN), but a subset of patients have menses despite marked weight loss and underweight. The aim of our study was to investigate parameters potentially influencing FHA in AN. DESIGN AND METHODS: In this observational retrospective study, we selected 114 female patients with AN who completed a 12 months semi-residential rehabilitation program and a subsequent 12 months outpatient follow-up. We divided our sample into three groups: "Group 0" patients who experienced FHA and recovered their menses, "Group 1" persistent FHA, "Group 2" never experienced FHA, and looked for clinical and hormonal correlations. RESULTS: At the enrollment, the BMI was higher in Group 2 than in Group 1 (p = 0.0202), but the last follow-up weight was higher in Group 1 (p < 0.0001) despite persistent amenorrhea. At logistic regression, the higher BMI at which patients experienced amenorrhea was the main prediction factor for persistent FHA. Notwithstanding comparable leptin levels at admission, they improved significantly at discharge only in Groups 0 and 2 (p = 0.0054 and p = 0.0104, respectively). FT3 at admission was significantly higher in Group 2 than in Group 0 (p = 0.0249). CONCLUSIONS: FHA does not correlate strictly with body weight variations in AN patients, indicating a multifactorial origin, likely including an individual predisposition. Higher FT3 levels identify patients who continue having menses at extremely low BMI. AN patients with persistent FHA constitute a subgroup in whom estroprogestins should be considered after significant weight recovery to prevent prolonged tissue hypoestrogenism.


Asunto(s)
Anorexia Nerviosa , Enfermedades Hipotalámicas , Femenino , Humanos , Amenorrea , Estudios Retrospectivos , Peso Corporal
2.
Clin Endocrinol (Oxf) ; 99(2): 206-216, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37272400

RESUMEN

Persistent symptoms in patients treated for hypothyroidism are common. Despite more than 20 years of debate, the use of liothyronine for this indication remains controversial, as numerous randomised trials have failed to show a benefit of treatment regimens that combine liothyronine (T3) with levothyroxine over levothyroxine monotherapy. This consensus statement attempts to provide practical guidance to clinicians faced with patients who have persistent symptoms during thyroid hormone replacement therapy. It applies to non-pregnant adults and is focussed on care delivered within the UK National Health Service, although it may be relevant in other healthcare environments. The statement emphasises several key clinical practice points for patients dissatisfied with treatment for hypothyroidism. Firstly, it is important to establish a diagnosis of overt hypothyroidism; patients with persistent symptoms during thyroid hormone replacement but with no clear biochemical evidence of overt hypothyroidism should first have a trial without thyroid hormone replacement. In those with established overt hypothyroidism, levothyroxine doses should be optimised aiming for a TSH in the 0.3-2.0 mU/L range for 3 to 6 months before a therapeutic response can be assessed. In some patients, it may be acceptable to have serum TSH below reference range (e.g. 0.1-0.3 mU/L), but not fully suppressed in the long term. We suggest that for some patients with confirmed overt hypothyroidism and persistent symptoms who have had adequate treatment with levothyroxine and in whom other comorbidities have been excluded, a trial of liothyronine/levothyroxine combined therapy may be warranted. The decision to start treatment with liothyronine should be a shared decision between patient and clinician. However, individual clinicians should not feel obliged to start liothyronine or to continue liothyronine medication provided by other health care practitioners or accessed without medical advice, if they judge this not to be in the patient's best interest.


Asunto(s)
Hipotiroidismo , Triyodotironina , Adulto , Humanos , Triyodotironina/uso terapéutico , Tiroxina , Medicina Estatal , Tirotropina
3.
Brain ; 145(12): 4264-4274, 2022 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-35929549

RESUMEN

A genetic deficiency of the solute carrier monocarboxylate transporter 8 (MCT8), termed Allan-Herndon-Dudley syndrome, is an important cause of X-linked intellectual and motor disability. MCT8 transports thyroid hormones across cell membranes. While thyroid hormone analogues improve peripheral changes of MCT8 deficiency, no treatment of the neurological symptoms is available so far. Therefore, we tested a gene replacement therapy in Mct8- and Oatp1c1-deficient mice as a well-established model of the disease. Here, we report that targeting brain endothelial cells for Mct8 expression by intravenously injecting the vector AAV-BR1-Mct8 increased tri-iodothyronine (T3) levels in the brain and ameliorated morphological and functional parameters associated with the disease. Importantly, the therapy resulted in a long-lasting improvement in motor coordination. Thus, the data support the concept that MCT8 mediates the transport of thyroid hormones into the brain and indicate that a readily accessible vascular target can help overcome the consequences of the severe disability associated with MCT8 deficiency.


Asunto(s)
Personas con Discapacidad , Discapacidad Intelectual Ligada al Cromosoma X , Trastornos Motores , Simportadores , Ratones , Animales , Humanos , Barrera Hematoencefálica/metabolismo , Discapacidad Intelectual Ligada al Cromosoma X/genética , Discapacidad Intelectual Ligada al Cromosoma X/metabolismo , Hipotonía Muscular/genética , Atrofia Muscular , Células Endoteliales/metabolismo , Transportadores de Ácidos Monocarboxílicos/genética , Transportadores de Ácidos Monocarboxílicos/metabolismo , Hormonas Tiroideas/metabolismo , Terapia Genética , Simportadores/genética , Simportadores/metabolismo
4.
Trop Anim Health Prod ; 55(1): 57, 2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36715891

RESUMEN

Thyroid hormones and Cortisol level are the essential biomarkers in the assessment of stress condition. This study was done to estimate the metabolic hormonal profile of Tharparkar and Sahiwal during heat stress condition. The experiment was conducted on two groups consisting of Tharparkar and Sahiwal animals (5 in each group) and the experimental period comprised a 7-day acclimatization period, a heat exposure period of 21 days at control (25 °C), moderate (35 °C) and severe (42 °C) heat stress within a 9-10-day recovery period between each exposure. The hormonal concentrations of T3, T4 and cortisol were determined in serum. The serum concentration of Thyroxine (T4) and tri-iodothyronine (T3) decreases whereas cortisol level increases in both the breeds when subjected to heat stress. However, the serum level of T4 was significantly (p < 0.05) more declined in Sahiwal as compared to Tharparkar but there was no significant difference found between the two breeds in serum T3 levels. The cortisol levels were elevated in both breeds during heat stress but significantly (p < 0.05) more elevated in the Sahiwal. Hence, observations of these hormonal profiles suggest a better thermo-adaptability in Tharparkar as compared to Sahiwal.


Asunto(s)
Enfermedades de los Bovinos , Trastornos de Estrés por Calor , Bovinos , Animales , Hidrocortisona , Respuesta al Choque Térmico , Tiroxina , Aclimatación , Trastornos de Estrés por Calor/veterinaria , Triyodotironina
5.
Am J Physiol Regul Integr Comp Physiol ; 314(5): R734-R740, 2018 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-29351420

RESUMEN

Besides its well-known action to stimulate thyroid hormone release, thyrotropin mRNA is expressed within the brain, and thyrotropin and its receptor have been shown to be present in brain areas that control feeding and gastrointestinal function. Here, the hypothesis that thyrotropin acts on receptors in the hindbrain to alter food intake and/or gastric function was tested. Fourth ventricular injections of thyrotropin (0.06, 0.60, and 6.00 µg) were given to rats with chronic intracerebroventricular cannulas aimed at the fourth ventricle. Thyrotropin produced an acute reduction of sucrose intake (30 min). The highest dose of thyrotropin caused inhibition of overnight solid food intake (22 h). In contrast, subcutaneous administration of corresponding thyrotropin doses had no effect on nutrient intake. The highest effective dose of fourth ventricular thyrotropin (6 µg) did not produce a conditioned flavor avoidance in a standardized two-bottle test, nor did it affect water intake or gastric emptying of glucose. Thyrotropin injected in the fourth ventricle produced a small but significant increase in rectal temperature and lowered plasma levels of tri-iodothyronin but did not affect plasma levels of thyroxine. In addition, there was a tendency toward a reduction in blood glucose 2 h after fourth ventricular thyrotropin injection ( P = 0.056). In conclusion, fourth ventricular thyrotropin specifically inhibits food intake, increases core temperature, and lowers plasma levels of tri-iodothyronin but does not affect gastromotor function.


Asunto(s)
Regulación de la Temperatura Corporal/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Conducta Alimentaria/efectos de los fármacos , Rombencéfalo/efectos de los fármacos , Respuesta de Saciedad/efectos de los fármacos , Tirotropina/administración & dosificación , Animales , Biomarcadores/sangre , Glucemia/metabolismo , Relación Dosis-Respuesta a Droga , Inyecciones Intraventriculares , Masculino , Ratas Sprague-Dawley , Receptores de Tirotropina/agonistas , Receptores de Tirotropina/metabolismo , Rombencéfalo/metabolismo , Factores de Tiempo , Triyodotironina/sangre
6.
Am J Geriatr Psychiatry ; 26(12): 1222-1230, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30236902

RESUMEN

OBJECTIVE: Low tri-iodothyronine (T3) syndrome is a predictor of poor prognosis in patients with stroke. Poststroke cognitive impairment (PSCI) is a common and important complication after stroke. The association between low T3 syndrome and PSCI is unclear. We aimed to explore the potential relationship between low T3 syndrome and PSCI in the acute phase of ischemic stroke at a 1-month follow-up visit. METHODS: In total, 314 ischemic stroke patients were consecutively enrolled in the study and followed up at 1 month. Thyroid hormones were measured within 24 hours after admission. Cognitive function was evaluated by the Mini-Mental State Exam (MMSE) 1 month after acute ischemic stroke. Cognitive impairment was defined as an MMSE score of less than 27. Cognitive impairment severity was categorized as severe, mild, or none (MMSE score <23, 23-26, or ≥27, respectively). RESULTS: According to the MMSE score, 182 participants (58.0%) had cognitive impairment 1 month after stroke. Patients with low T3 syndrome were more prone to have cognitive impairment than patients with normal levels of T3 (p < 0.001). After adjusting for potential confounders in our logistic model, low T3 syndrome was independently associated with PSCI (odds ratio 4.319, 95% confidence interval 1.553-12.013, p = 0.005). CONCLUSION: Low T3 syndrome in the acute phase of ischemic stroke was associated with a higher prevalence of 1-month PSCI, independently of established risk factors.


Asunto(s)
Isquemia Encefálica , Disfunción Cognitiva , Hipotiroidismo , Accidente Cerebrovascular , Triyodotironina/sangre , Adulto , Isquemia Encefálica/sangre , Isquemia Encefálica/complicaciones , Isquemia Encefálica/fisiopatología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Hipotiroidismo/sangre , Hipotiroidismo/complicaciones , Masculino , Pruebas de Estado Mental y Demencia , Persona de Mediana Edad , Estudios Prospectivos , Accidente Cerebrovascular/sangre , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/fisiopatología
7.
J Pak Med Assoc ; 68(10): 1488-1492, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30317347

RESUMEN

OBJECTIVE: To determine the reference values for thyroid stimulating hormone, free tetra-iodothyronine and total tri-iodothyronine for healthy pregnant women. METHODS: This cross sectional study was conducted at the Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from January 2016 to June 2017. Pregnant women with normal, single intrauterine, uncomplicated pregnancy were recruited from the local population. Blood sample was taken to analyse thyroid stimulating hormone, free tetra-iodothyronine and total tri-iodothyronine using chemiluminescence immunoassay. For thyroid hormone levels during each trimester 5th and 95th percentiles were calculated as reference intervals. Data was analysed using SPSS 24. RESULTS: Out of 384 subjects, 188(48.95%) were in their first trimester and 196(51.04 %) females were in their second trimester. There were 109(57.97%) primigravida in the first trimester and 137(69.9%) in the second trimester. Mean age of subjects presenting in the first and second trimester was 25.37±3.78 years and 26.54±4.65 years respectively. Reference intervals for those in the first trimester for thyroid stimulating hormone was 0.05-2.8uIU/ml, for free tetra-iodothyronine14.4-22.7pmol/l and total tri-iodothyronine1.5-3.3nmol/l. For those in second trimester the corresponding values were 0.16-3.3 uIU/ml, 14.2-24.6.0 pmol/l and 1.6-3.1nmol/l. CONCLUSIONS: Laboratories should adopt trimester-specific reference intervals for thyroid function tests in pregnancy..


Asunto(s)
Paridad , Trimestres del Embarazo/sangre , Hormonas Tiroideas/sangre , Población Urbana , Adulto , Biomarcadores/sangre , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Pakistán , Embarazo , Valores de Referencia , Estudios Retrospectivos , Pruebas de Función de la Tiroides
8.
J Neurooncol ; 131(2): 385-391, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27830477

RESUMEN

Reduced triiodothyronine (T3) concentrations were implicated in worse prognosis of brain tumor patients. In this study we investigated the association of normal and abnormal thyroid hormone concentrations with health-related quality of life (HRQoL) of patients with primary brain tumors. Sixty-three patients (67% women and a mean age of 55.5 ± 13.8 years) before brain tumor surgery were evaluated for: (1) HRQoL using the EORTC questionnaire for cancer patients (QLQ-C30) and the Brain Cancer-Specific Quality of Life Questionnaire (QLQ-BN20); (2) functional status (Barthel Index); and (3) clinical disease severity. Blood samples were obtained for assessment of thyroid hormone concentrations before surgery. After adjusting for the brain tumor histological diagnosis, patients' age, gender and functional status, lower thyroid stimulating hormone (TSH) concentrations were associated with poor levels of functioning on the QLQ-C30 scales: physical functioning (ß = 0.395, p < 0.001), role functioning (ß = 0.334, p = 0.003) and cognitive functioning (ß = 0.327, p = 0.009), and with greater QLQ-BN20 fatigue symptom severity (ß = -0.406, p < 0.001). Lower free T3 concentrations were associated with worse HRQOL on the QLQ-C30 global health status (ß = 0.302, p = 0.017), emotional functioning (ß= 0.422, p < 0.001) and cognitive functioning (ß= 0.259, p = 0.042) domains, and with greater symptom severity on the QLQ-BN20 fatigue (ß = -0.238, p = 0.041), motor dysfunction (ß = -0.283, p = 0.013) and weakness of legs (ß = -0.269. p = 0.027) domains. In conclusion, reduced T3 and TSH hormone concentrations are associated with impaired emotional and physical aspects of HRQoL of primary brain tumor patients independent of brain tumor histological diagnosis, patients' age, gender and functional status. Assessment for thyroid axis dysfunction should be addressed and appropriately managed in neuro-oncology patient care.


Asunto(s)
Neoplasias Encefálicas/sangre , Neoplasias Encefálicas/psicología , Calidad de Vida , Tirotropina/sangre , Tiroxina/sangre , Triyodotironina/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto
9.
Br J Nutr ; 117(7): 951-963, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28443527

RESUMEN

An experiment was conducted to determine: (1) the effect of excess maternal I supplementation on the thyroid hormone status of the ewe and her progeny; (2) potential mechanisms underpinning the failure of passive transfer associated with excess I and (3) the growing lambs' response to natural gastrointestinal infection. Twin-bearing ewes received one of two treatments (n 32/treatment group): basal diet (C) or C plus 26·6 mg of iodine/ewe per d (I), supplied as calcium iodate. Ewes were individually fed from day 119 of gestation to parturition. Progeny of I ewes had lower (P<0·01) serum IgG concentrations from 24 h to 28 d postpartum but higher serum IgG concentrations at day 70 postpartum (P<0·05). I supplementation increased the relative expression of Fc receptor, IgA, IgM high affinity and polymeric Ig receptor in the ileum of the lamb at 24 h postpartum; however, thyroid hormone receptor-ß (THRB) and ß-2-microglobulin (B2M) expression declined (P<0·05). Progeny of I ewes had higher growth rates to weaning (P<0·05) and lower faecal egg count (FEC) for Nematodirus battus (P<0·05) between weeks 6 and 10 postpartum. In conclusion, excess maternal I supplementation negatively affected the thyroid hormone status, serum IgG concentration, ileal morphology and the gene expression of THRB and B2M in the ileum and ras-related protein (RAB) RAB25 and the mucin gene (MUC) MUC1 in the duodenum of the lamb postpartum. These effects were followed by an enhancement of average daily gain and lower N. battus FEC in the pre-weaning period of I-supplemented lambs.


Asunto(s)
Calostro/inmunología , Suplementos Dietéticos , Inmunidad Materno-Adquirida , Yodo/uso terapéutico , Fenómenos Fisiologicos Nutricionales Maternos , Enfermedades de las Ovejas/prevención & control , Infecciones por Strongylida/veterinaria , Animales , Animales Recién Nacidos , Calostro/química , Suplementos Dietéticos/efectos adversos , Femenino , Regulación del Desarrollo de la Expresión Génica , Íleon/crecimiento & desarrollo , Íleon/inmunología , Íleon/metabolismo , Íleon/patología , Inmunoglobulina G/análisis , Inmunoglobulina G/biosíntesis , Mucosa Intestinal/crecimiento & desarrollo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Yodo/efectos adversos , Masculino , Nematodirus/inmunología , Nematodirus/aislamiento & purificación , Recuento de Huevos de Parásitos/veterinaria , Embarazo , Distribución Aleatoria , Ovinos , Enfermedades de las Ovejas/inmunología , Enfermedades de las Ovejas/metabolismo , Enfermedades de las Ovejas/parasitología , Oveja Doméstica , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/parasitología , Infecciones por Strongylida/prevención & control , Receptores beta de Hormona Tiroidea/genética , Receptores beta de Hormona Tiroidea/metabolismo , Aumento de Peso , Microglobulina beta-2/genética , Microglobulina beta-2/metabolismo
10.
Pak J Med Sci ; 32(1): 111-5, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27022356

RESUMEN

OBJECTIVES: The objective of this research was to elucidate some of the major relation of thyroid dysfunctions, keeping in view the various selected demographic details of included patients. METHODS: This study was approved by the ethical committee of Post Graduate Medical Institute (PGMI) Hayatabad Medical Complex Peshawar, and was conducted in the Institute of Radioactive Nuclear Medicine (IRNUM) Peshawar. The blood samples were collected, followed by their analysis for triiodothyronine (T3), tetraiodothyronine (T4) and thyroid stimulating hormone (TSH). RESULTS: The results obtained regarding the demographical aspects of the patients revealed that female gender has categorically significantly high percentage of occurrence of thyroid abnormality as compared to male gender (75.8% vs. 24.2%). Results regarding locality distribution of the patients depicted that majority of those belonged to the local population of Peshawar and Charsadda region. CONCLUSION: In Pakistan especially Khyber Pakhtunkwa (KPK), thyroid diseases are more common in females as compared to males. The most probable causes could be lactation and pregnancy.

11.
Pak J Med Sci ; 30(6): 1356-60, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25674138

RESUMEN

Objective : The present study was designed to investigate variations in the levels of thyroid hormones (T3, T4) in breast and ovarian cancers patients. Methods : A total 120 subjects were recruited (without thyroid history) divided into three groups; A, B and C. Group A as control with healthy individuals. While group B and group C were consisting of breast cancer and ovarian cancer patient respectively. Blood samples (5 ml) were taken and analyzed to estimate the levels of serum T3 (tri-iodothyronine) and T4 (thyroxin) hormones. R esults : Statistically significant difference (P=0.000* and P=0.017*) was obtained among all groups. A significant increase in T3 (P=0.000*) and T4 (0.005*) levels was observed among breast cancer patients as compared to healthy controls. While for ovarian cancer patients conflicting results were found for T3 and T4 levels in the serum i.e. insignificant difference was found in T3 (P=0.209) and T4 (P=0.050) as compared to control. Our results showed that in the breast cancer and ovarian cancer patients the thyroid hormone (T3 and T4) level has been altered from the normal ranges as compared to the normal healthy individuals. Conclusion : We conclude that hyperthyroidism has profound effects on breast cancer and ovarian cancer cells proliferation.

12.
Front Endocrinol (Lausanne) ; 14: 1164369, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37305055

RESUMEN

Background: Low thyroxine (T4) levels have been observed in critically ill patients; however, controversial results regarding T4 supplemental therapy are reported. The association between serum free T4 (FT4) levels and mortality in critically ill patients has not been fully established and needs to be clarified. Methods: Data from the Medical Information Mart for Intensive Care (MIMIC)-IV were collected and analyzed. The association between FT4 level and 30-day mortality after ICU admission was analyzed using Kaplan-Meier curves, spline smoothing fitting, martingale residuals of the null Cox model, and restricted cubic spline (RCS). Logistic regression, Cox regression, and receiver operating characteristic curve (ROC) were used to uncover the relationship and predictive value of serum FT4 and 30-day mortality in critically ill patients. Results: In the final analysis, 888 patients were enrolled, and the serum FT4 levels were divided into four groups. A significant difference in 30-day mortality was observed between the four groups. Kaplan-Meier curves also presented significantly higher 30-day mortality in groups 1 and 2 (p < 0.0001). Further multivariance logistic regression showed that group 1 with FT4 levels lower than 0.7 µg/dl can predict 30-day mortality (odds ratio (OR) = 3.30, 95% confidence interval (CI) = 1.04-11.31). Spline smoothing fitting analysis showed a "V"-shaped line between 30-day mortality and FT4 level within 0-3 µg/dl. Further RCS analysis showed that the risk of death decreased rapidly as FT4 levels increased when serum FT4 levels were lower than 1.2 µg/dl and started to become flat afterward. The area under the ROC of the lower FT4 level to predict 30-day mortality was 0.833 (95% CI = 0.788-0.878). Both multivariant Cox regression and logistic regression showed that FT4 levels lower than 1.2 µg/dl can independently predict 30-day mortality when adjusted for other potential confounders (HR = 0.34, 95% CI = 0.14-0.82; OR = 0.21, 95% CI = 0.06-0.79, respectively), but its predictive power disappeared when adjusted for T3 or total T4. Conclusion: Serum FT4 levels were significantly negatively associated with 30-day mortality when they were lower than 1.2 µg/dl and could predict the risk of 30-day mortality. A higher FT4 level is potentially related to increased 30-day mortality.


Asunto(s)
Enfermedad Crítica , Tiroxina , Humanos , Estudios Retrospectivos , Pruebas de Función de la Tiroides , Cuidados Críticos
13.
Ther Adv Endocrinol Metab ; 14: 20420188231158163, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36936128

RESUMEN

Background: Thyroid hormones are controlled by the hypothalamic-pituitary-thyroid (HPT) axis through a complex network of regulatory loops, involving the hormones TRH, TSH, FT4, and FT3. The relationship between TSH and FT4 is widely used for diagnosing thyroid diseases. However, mechanisms of FT3 homeostasis are not well understood. Objective: We used mathematical modelling to further examine mechanisms that exist in the HPT axis regulation for protecting circulating FT3 levels. Methods: A mathematical model consisting of a system of four coupled first-order parameterized non-linear ordinary differential equations (ODEs) was developed, accounting for the interdependencies between the hormones in the HPT axis regulation. While TRH and TSH feed forward to the pituitary and thyroid, respectively, FT4 and FT3 feed backward to both the pituitary and hypothalamus. Stable equilibrium solutions of the ODE system express homeostasis for a particular variable, such as FT3, if this variable stays in a narrow range while certain other parameter(s) and system variable(s) may vary substantially. Results: The model predicts that (1) TSH-feedforward protects FT3 levels if the FT4 production rate declines and (2) combined negative feedback by FT4 and FT3 on both TSH and TRH production rates keeps FT3 levels insensitive to moderate changes in FT4 production rates and FT4 levels. The optimum FT4 and FT3 feedback and TRH and TSH-feedforward ranges that preserve FT3 homeostasis were found by numerical continuation analysis. Model predictions were in close agreement with clinical studies and individual patient examples of hypothyroidism and hyperthyroidism. Conclusions: These findings further extend the concept of HPT axis regulation beyond TSH and FT4 to integrate the more active sister hormone FT3 and mechanisms of FT3 homeostasis. Disruption of homeostatic mechanisms leads to disease. This provides a perspective for novel testable concepts in clinical studies to therapeutically target the disruptive mechanisms.

14.
J Clin Endocrinol Metab ; 108(11): 2886-2897, 2023 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-37200150

RESUMEN

CONTEXT: Optimal thyroid status in pregnancy is essential in reducing the risk of adverse outcomes. The management of hyperthyroidism in women of reproductive age poses unique challenges and it is unclear how preconception treatment strategies impact on thyroid status in subsequent pregnancy. OBJECTIVE: We aimed to determine trends in the management of hyperthyroidism before and during pregnancy and to assess the impact of different preconception treatment strategies on maternal thyroid status. METHODS: We utilized the Clinical Practice Research Datalink database to evaluate all females aged 15-45 years with a clinical diagnosis of hyperthyroidism and a subsequent pregnancy (January 2000 to December 2017). We compared thyroid status in pregnancy according to preconception treatment, namely, (1) antithyroid drugs up to or beyond pregnancy onset, (2) definitive treatment with thyroidectomy or radioiodine before pregnancy, and (3) no treatment at pregnancy onset. RESULTS: Our study cohort comprised 4712 pregnancies. Thyrotropin (TSH) was measured in only 53.1% of pregnancies, of which 28.1% showed suboptimal thyroid status (TSH >4.0 mU/L or TSH <0.1 mU/L plus FT4 >reference range). Pregnancies with prior definitive treatment were more likely to have suboptimal thyroid status compared with pregnancies starting during antithyroid drug treatment (odds ratio 4.72, 95% CI 3.50-6.36). A steady decline in the use of definitive treatment before pregnancy was observed from 2000 to 2017. One-third (32.6%) of first trimester carbimazole-exposed pregnancies were switched to propylthiouracil while 6.0% of propylthiouracil-exposed pregnancies switched to carbimazole. CONCLUSION: The management of women with hyperthyroidism who become pregnant is suboptimal, particularly in those with preconception definitive treatment, and needs urgent improvement. Better thyroid monitoring and prenatal counseling are needed to optimize thyroid status, reduce teratogenic drug exposure, and ultimately reduce the risk of adverse pregnancy outcomes.


Asunto(s)
Hipertiroidismo , Tiroxina , Embarazo , Femenino , Humanos , Tiroxina/uso terapéutico , Propiltiouracilo , Carbimazol , Radioisótopos de Yodo , Estudios de Cohortes , Hipertiroidismo/tratamiento farmacológico , Hipertiroidismo/epidemiología , Tirotropina , Antitiroideos/efectos adversos , Pruebas de Función de la Tiroides
15.
Thyroid Res ; 16(1): 7, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-37009883

RESUMEN

BACKGROUND: Thyroid hormones are key determinants of health and well-being. Normal thyroid function is defined according to the standard 95% confidence interval of the disease-free population. Such standard laboratory reference intervals are widely applied in research and clinical practice, irrespective of age. However, thyroid hormones vary with age and current reference intervals may not be appropriate across all age groups. In this review, we summarize the recent literature on age-related variation in thyroid function and discuss important implications of such variation for research and clinical practice. MAIN TEXT: There is now substantial evidence that normal thyroid status changes with age throughout the course of life. Thyroid stimulating hormone (TSH) concentrations are higher at the extremes of life and show a U-shaped longitudinal trend in iodine sufficient Caucasian populations. Free triiodothyronine (FT3) levels fall with age and appear to play a role in pubertal development, during which it shows a strong relationship with fat mass. Furthermore, the aging process exerts differential effects on the health consequences of thyroid hormone variations. Older individuals with declining thyroid function appear to have survival advantages compared to individuals with normal or high-normal thyroid function. In contrast younger or middle-aged individuals with low-normal thyroid function suffer an increased risk of adverse cardiovascular and metabolic outcomes while those with high-normal function have adverse bone outcomes including osteoporosis and fractures. CONCLUSION: Thyroid hormone reference intervals have differential effects across age groups. Current reference ranges could potentially lead to inappropriate treatment in older individuals but on the other hand could result in missed opportunities for risk factor modification in the younger and middle-aged groups. Further studies are now needed to determine the validity of age-appropriate reference intervals and to understand the impact of thyroid hormone variations in younger individuals.

16.
Clin Med Insights Oncol ; 16: 11795549221139522, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36532699

RESUMEN

Background: Endocrine hormones influence tumor progression and the response to treatment. Despite the importance of immune checkpoint inhibitors (ICIs) as treatments for advanced non-small cell lung cancer (NSCLC), few studies have explored the effects of hormone levels in NSCLC patients on the effectiveness of ICI therapies. We thus investigated the effects of baseline blood markers in patients with advanced NSCLC on ICI treatments. Methods: Patients with advanced NSCLC who received programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors at Chungnam National University Hospital between December 2016 and November 2020 and who lacked any history of thyroid gland-related diseases were analyzed retrospectively. We collected clinical information and baseline laboratory data, including the levels of endocrine hormones, cytokines, complete blood counts (CBCs), and peripheral blood chemistry panels. We explored the relationships of hormone levels with clinical outcomes (overall survival [OS], progression-free survival [PFS], and best response), liver metastasis, and blood markers using the Kaplan-Meier method, Cox's proportional hazards regression, and logistic regression. Results: A total of 113 patients were enrolled. A shorter PFS was independently associated with liver metastasis, higher cortisol levels, and lower hemoglobin (Hb) levels; a shorter OS was associated with liver metastasis, lower tri-iodothyronine (T3) levels, higher lactate dehydrogenase (LDH) levels, and lower albumin levels. Patients with low T3 levels exhibited a shorter PFS and OS, and a poorer best response. Patients with low T3 levels tended to have higher disease progression rates, lower levels of adrenocorticotropic hormone (ACTH), C-peptide, albumin, Hb, and neutrophil-to-lymphocyte ratio, and higher levels of interleukin (IL)-6, white blood cells, platelets, compared with those with normal T3 levels. We found a significant association between a low T3 level and liver metastasis. Conclusions: We found the baseline T3 level was associated with both prognosis and the response to ICIs in patients with advanced NSCLC, probably reflecting impaired liver function and systemic inflammation induced by the interaction of T3 with other biomarkers, such as IL-6, ACTH, cortisol, C-peptide, Hb, LDH, and albumin.

19.
Pan Afr Med J ; 40: 9, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34650659

RESUMEN

INTRODUCTION: the outbreak and rapid spread of the novel SARS-CoV-2, the causative agent of the coronavirus disease 2019 (COVID-19), has evolved into an unprecedented global pandemic. The infection impairs several human organs and systems, however, it is not clear how it affects thyroid function. The study therefore aimed at measuring plasma levels of thyroid hormones and Hs-CRP in COVID-19 patients and apparently healthy uninfected controls to assess the possible effect of SAR-CoV-2 infection on thyroid function. METHODS: in this cross-sectional study carried out between May-August 2020, 90 consenting participants comprising 45 COVID-19 patients and 45 apparently healthy uninfected controls were recruited. Plasma FT3, FT4, TSH and Hs-CRP were measured using Enzyme Linked Immunosorbent Assay (ELISA) method. Data was analysed using SPSS version 20 and statistical significance set at p < 0.05. RESULTS: the mean plasma FT3 and TSH concentrations were significantly higher in COVID-19 patients compared to controls (p < 0.001, p < 0.001 respectively). Euthyroidism was observed in all uninfected controls, whereas 35 (77.8%) COVID-19 patients were euthyroid. Sick euthyroid and subclinical hypothyroidism was observed in 7 (15.6%) and 3 (6.7%) COVID-19 patients, respectively. CONCLUSION: though there was a preponderance of euthyroidism among COVID-19 patients, significantly higher mean plasma levels of TSH and FT3, sick euthyroid syndrome and subclinical hypothyroidism observed among some COVID-19 patients may be indicative of disease-related thyroid function changes. Hence, there is need to pay attention to thyroid function during and after treatment of COVID-19.


Asunto(s)
COVID-19/complicaciones , Síndromes del Eutiroideo Enfermo/epidemiología , Hipotiroidismo/epidemiología , Enfermedades de la Tiroides/epidemiología , Adulto , Estudios de Casos y Controles , Estudios Transversales , Síndromes del Eutiroideo Enfermo/virología , Femenino , Humanos , Hipotiroidismo/virología , Masculino , Persona de Mediana Edad , Nigeria , Enfermedades de la Tiroides/virología , Hormonas Tiroideas/sangre , Adulto Joven
20.
Animals (Basel) ; 11(9)2021 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-34573702

RESUMEN

In this study, a maternal feed restriction (MFR; 105 g/d) in primiparous rabbit does was applied from day 0 to 7 post artificial insemination (AI) (R07, n = 96), from day 7 to 21 post AI (R721, n = 92), from day 0 to 21 post AI (R021, n = 94) or fed ad libitum during whole pregnancy (Control, n= 92). Feed intake (FI) was measured after MFR was over. On day 28 of gestation, fetoplacental development was evaluated (n = 11/group) and the productive parameters of the remaining dams were analyzed. Plasma free tri-iodothyronine (T3) and thyroxine, glucose, insulin, non-esterified fatty acids (NEFA), and corticosterone were analyzed during gestation and lactation (n = 5/group). After MFR, all groups significantly increased their voluntary FI. The longer MFR was, the lower the weight and length of the fetuses, but no long-term effects over litter performance were observed. R021 groups had the lowest T3 and the highest NEFA concentrations during pregnancy and showed insulin resistance at the end of gestation, but during lactation, energy homeostasis was balanced in all groups. MFR did not affect corticosterone concentrations. In conclusion, the ration setting applied slightly involved the energy homeostasis and metabolism of the animals, but their overall metabolic condition, productive performance and welfare were not compromised.

SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda