Arterial hypertension represents a major global health concern; more than one fourth of the population is affected by high blood pressure. Albeit the underlying cause of the disease remains unclear in the vast majority of the cases, ~10% are of secondary origin. Endocrine disorders are common illnesses and some of them may lead to elevated blood pressure, among which thyroid diseases are of high prevalence and often overlooked, especially in mild cases. Overt and subclinical hyper- and hypothyroidism can both lead to (mostly mild) hypertension; however, the underlying mechanisms are only partially understood. The results of clinical studies are often controversial. During the past decades, some genetic mutations in the hypothalamus-pituitary-thyroid axis with cardiovascular consequences were revealed. Atherosclerotic changes resulting from lipid abnormalities due to thyroid dysfunction also affect the vasculature and can cause elevated blood pressure. The review gives a synopsis of our knowledge how thyroid hormone metabolism and functional thyroid diseases affect the cardiovascular system, their negative impact and causative role in the development of hypertension.
P-glycoprotein (Pgp), an ATP-dependent efflux transporter that protects the body from environmental toxins and xenobiotics, is encoded by the human MDR1 gene. Human MDR1 is located on chromosomal region 7q21. Although several different single nucleotide polymorphisms were shown to influence Pgp expression and activity, the reported length of the MDR1 gene in Genbank and other databases continues to evolve and varies between 6.3 kilobases (kb) and 210 kb. With DNA derived from human cell lines and tissues, we have characterized the MDR1 genomic sequence to be 209 kb.
Pregnant women are prone to iodine deficiency due to the increased need for iodine during gestation. Progress has recently occurred in establishing serum thyroglobulin (Tg) as an iodine status biomarker, but there is no accepted reference range for iodine sufficiency during pregnancy. An observational study was conducted in 164 pregnant women. At week 16 of gestation urinary iodine concentration (UIC), serum Tg, and thyroid functions were measured, and information on the type of iodine supplementation and smoking were recorded. The parameters of those who started iodine supplementation (≥150 μg/day) at least 4 weeks before pregnancy (n = 27), who started at the detection of pregnancy (n = 51), and who had no iodine supplementation (n = 74) were compared. Sufficient iodine supply was found in the studied population based on median UIC (162 μg/L). Iodine supplementation ≥150 μg/day resulted in higher median UIC regardless of its duration (nonusers: 130 μg/L vs. prepregnancy iodine starters: 240 μg/L, and pregnancy iodine starters: 205 μg/L, p < .001, and p = .023, respectively). Median Tg value of pregnancy starters was identical to that of nonusers (14.5 vs. 14.6 μg/L), whereas prepregnancy starters had lower median Tg (9.1 μg/L, p = .018). Serum Tg concentration at week 16 of pregnancy showed negative relationship (p = .010) with duration of iodine supplementation and positive relationship (p = .008) with smoking, a known interfering factor of iodine metabolism, by multiple regression analysis. Serum Tg at week 16 of pregnancy may be a promising biomarker of preconceptual and first trimester maternal iodine status, the critical early phase of foetal brain development.
Corticosteriod treatment is associated with a decline in DTPA uptake in a fraction of GO patients. GO patients with a DTPA uptake above 12.28 MBq/cm(3) are more likely to have a favorable response to corticosteroid therapy while patients with lower values are less likely to have this potentially favorable response. An elevated DTPA uptake may identify patients who are most likely to benefit from immunosuppressive treatment.
The aim of this investigations was to study the effectiveness of anti-CD20 antibody therapy in Graves' orbitopathy (GO) resistant to glucocorticoids. Five patients were entered in the study. The protocol required no improvement of orbital status after a recent course of glucocorticoids. Activity of GO was confirmed by three independent techniques: clinical activity score (CAS), (99m)Tc-labeled diethylene triamine pentaacetic acid ((99m)Tc DTPA) single photon emission computed tomography and magnetic resonance imaging. Rituximab (RTX) was given as weekly infusions of 375 mg/m(2) body surface area for four weeks. The mean follow-up period was 67 (range 58-81) months. Improvement of GO has been observed in all patients: CAS before therapy was 6.5 ± 1.7 and decreased to 3.4 ± 1.6 by one month (p < 0.05) and remained unchanged (3.2 ± 1.7) at 12 months. No further CAS change, in either direction, was detected during the yearly follow-up visits. The mean DTPA uptake before therapy was 16.52 ± 4.51 MBq/cm(3) and decreased to 11.97 ± 2.36 MBq/cm(3) at one year (p < 0.002). The mean of T2 relaxation times before and one year after therapy were 96.91 ± 17.61 ms and 84.29 ± 9.41 ms, respectively (p < 0.001). The mean serum TSH receptor antibody (TRAb) levels before therapy, at the one month and one year control visits were 7.4 ± 3.4 U/L, 5.6 ± 4.5 U/L and 1.7 ± 1.5 U/L, respectively (p < 0.004). No correlation between changes of TRAb and activity parameters has been found. Anti-CD20 treatment seems to influence positively the clinical course of GO, and this effect seems to be stable for five years. To our knowledge, this is the longest published follow-up of RTX treatment in GO.
Abstract:Objective: The aim of this study was to investigate aortic stiffness and left ventricular systolic and diastolic function in patients with differentiated thyroid cancer (DTC) on thyroxin (L-T4) therapy and after L-T4 withdrawal in order to assess the cardiovascular impact of long-term subclinical hyperthyroidism and short-term overt hypothyroidism. Design: Twenty four patients who had had total thyroidectomy and radioiodine ablation for differentiated thyroid cancer were studied on two occasions: on TSH suppressive L-T4 therapy (sTSH 0.24±0.11 mU/L), and four weeks after L-T4 withdrawal (sTSH 89.82±29.36 mU/L). Echocardiography was performed and thyroid function, serum thyroglobulin, lipid parameters, homocystine, C-reactive protein, fibrinogen and von Willebrandt factor activity (vWF) were measured. Twenty two healthy volunteers matched for age and sex served as euthyroid controls. Results: Aortic stiffness was increased both in hypothyroidism (6.04±2.88 cm2/dyn/103, p< 0.05) and subclinical hyperthyroidism (9.27±4.81 cm2/dyn/103, p<0.05) vs. controls (3.92±1.84 cm2/dyn/103). Subclinical hyperthyroidism had a more marked effect (p<0.05). LV dimensions and ejection fractions were similar before and after L-T4 withdrawal. The E'/A' was higher in euthyroid controls (1.34±1.02) as compared to both subclinical hyperthyroidism (1.0±0.14, p<0.05) and overt hypothyroidism (1.13±0.98, p<0.05). Change of aortic stiffness correlated with change of free-thyroxine (fT4), vWF and fibrinogen levels in a positive manner. Conclusion: Long-term thyrotropin-suppression therapy has continuous adverse effects on the arterial wall. The degree of TSH suppression in patients with DTC should be kept at the possible minimum, based on individually determined potential benefits and risks of treatment, especially in patients with cardiovascular comorbidities. Dear Professor Bartalena,We would like to thank you for the suggestions which have contributed to the improvement of our paper entitled "Aortic stiffness and left ventricular function in patients with differentiated thyroid cancer", JENI-D-14-00120 .We have corrected the manuscript and we hope that you will find it worth publishing in the Journal of Endocrinological Investigation.We provide a detailed point-by-point response to each of the referees' concerns, describing exactly how we responded to each point and where you can find the amendment in the revised manuscript.Thank you very much for your patience and kind help. •How many time elapsed from thyroidectomy/RAI ablation and the current tests?20±12,6 months elapsed before the start of this study. This information has been added to page 4, line 47.•What was the thyroglobulin serum level at the time of aortic examination? In other words, were all the patients without evidence of persistent/recurrent disease (also by the biochemical point of view)? / Did the Authors evaluate the level of serum anti-Tg antibodies?The first off-T4 Tg measurrment was at least 6 months after RAI in parallel with anti-Tg antibody. Four of twenty...
Összefoglaló. Bevezetés: A pajzsmirigy-alulműködés gyakori betegség. Kezelésében a levotiroxin (LT4)-pótlás a szokásos eljárás, mely tabletta vagy gélkapszula formájában áll rendelkezésre Magyarországon. A nemzetközi trendeknek megfelelően az esetek korai felismerése miatt már a kevésbé kifejezett hormonális eltérések idején elindul a kezelés. Az endokrinológusok hypothyreosiskezelési szokásaival kapcsolatban Magyarországon és Európában felmérés eddig nem történt. Célkitűzés: A THESIS (Treatment of Hypothyroidism in Europe by Specialists: an International Survey) célja, hogy felmérjük az európai és közte jelen munkánkban a magyar endokrinológusok hypothyreosiskezelési szokásait és az LT4 esetleges alkalmazását pajzsmirigy-működészavarral nem járó állapotokban. Módszer: A Magyar Endokrinológiai és Anyagcsere Társaság (MEAT) tagjainak e-mailben meghívót küldtünk az online kérdőíves vizsgálathoz. Eredmények: 165 magyar endokrinológus válaszai alapján végeztük az elemzést. A válaszadók többsége, 99,4%-uk első kezelésként LT4-pótlást alkalmaz. Az LT4 + LT3 kombinációt elsősorban olyan betegeknél alkalmazzák, akik LT4 szedése mellett euthyreoid hormonértékek ellenére hypothyreosisra jellemző tüneteket mutatnak (36,1%). Euthyreoid hormonértékek mellett, magas antitestszint és infertilitás esetén 60,3% megfontolná LT4 indítását, amit evidenciák jelenleg nem indokolnak. Számos kórállapot befolyásolja az LT4 felszívódását, ezekben az esetekben a magyar endokrinológusok 66,4%-a preferálja a lágy kapszula alkalmazását, jobb eredményt várva a gyógyszerformák közötti váltástól. Következtetés: A pajzsmirigy-alulműködés kezelésében a magyar endokrinológusok elsődlegesen az LT4-et választják. Az LT4 + LT3 kombinált alkalmazását a pajzsmirigy-stimuláló hormon normális szintjének elérése után perzisztáló hypothyreosisos tünetek esetén fontolják meg. Az újabb gyógyszerformákat a többség preferálja, ha az LT4 hagyományos tablettás formájának alacsonyabb biohasznosulása várható. Orv Hetil. 2022; 163(12): 463–472. Summary. Introduction: Hypothyroidism has a high prevalence in the adult population. Levothyroxine (LT4) supplementation is considered to be the gold-standard treatment method. In Hungary, LT4 tablets and soft gel capsules are the available formulations. Similarly to the international trends, hypothyroidism is earlier recognised, leading to early LT4 supplementation. Up till now, there has been no survey on the treatment of hypothyroidism among Hungarian endocrinologists. Objective: THESIS (Treatment of Hypothyroidism in Europe by Specialists: an International Survey) had been conducted to assess treatment preferences among European endocrinologists. Here we report the results on the use of thyroid hormones in hypothyroid patients and euthyroid individuals in Hungary. Method: An e-mail invitation to participate, containing the link to the online survey was sent to members of the Hungarian Society for Endocrinology and Metabolism. Results: There were 165 responses with full demographics which were included in the analysis. By the majority (99.4%) of them, LT4 was the first treatment of choice. LT4 + LT3 combination was considered an option in patients with persistent symptoms despite biochemical euthyroidism while on LT4 (36,1%). In euthyroid individuals, 60.3% of the respondents would consider starting LT4 in euthyroid infertile women with high antibody levels, which is hardly supported by evidence. In the presence of comorbidities and interfering medications which may hinder LT4 absorption, 66.4% of Hungarian endocrinologist anticipate significant improvement after switching from tablets to soft gel capsules. Conclusion: The treatment of choice for hypothyroidism is LT4 in Hungary. Combination therapy with LT4 + LT3 was considered for patients with persistent symptoms. In the presence of diseases and interfering medications affecting bioavailability, a high number of Hungarian endocrinologists prefer the new LT4 formulation. The administration of LT4 in euthyroid conditions awaits explanation and calls for intensive discussions at local conferences and courses. Orv Hetil. 2022; 163(12): 463–472.
PURPOSE. Hyaluronan (HA) overproduction by orbital fibroblasts (OFs) is a major factor in the pathogenesis of Graves' orbitopathy (GO). 4-methylumbelliferone (4-MU) is an inhibitor of HA synthesis in different cell types in vitro and has beneficial effects in animal models of autoimmune diseases. METHODS. HA production and mRNA expression of HA synthases (HAS1, HAS2, and HAS3) and hyaluronidases (HYAL1 and HYAL2) were measured in the presence and absence of 4-MU in unstimulated and transforming growth factor-β-stimulated fibroblasts from GO orbital (n = 4), non-GO orbital (n = 4), and dermal origin (n = 4). RESULTS. The 4-MU treatment (1 mM) for 24 hours resulted in an average 87% reduction (P < 0.001) of HA synthesis, decreased the expression of the dominant HAS isoform (HAS2) by 80% (P < 0.0001), and increased the HYAL2 expression by 2.5-fold (P < 0.001) in control OFs, GO OFs, and dermal fibroblasts (DFs) regardless of the origin of the cells. The proliferation rate of all studied cell lines was reduced to an average 16% by 4-MU (P < 0.0001) without any effects on cell viability. HA production stimulated by transforming growth factor-β was decreased by 4-MU via inhibition of stimulated HAS1 expression in addition to the observed effects of 4-MU in unstimulated cases. Characteristics of HA synthesis inhibition by 4-MU did not differ in OFs compared with DFs. CONCLUSIONS. 4-MU has been found to inhibit the HA synthesis and the proliferation rate in OFs in vitro, adding it to the list of putative therapeutic agents in a disease the cure of which is largely unresolved.
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