1
|
Deguchi-Horiuchi H, Ito M, Takahashi S, Kousaka K, Hisakado M, Fukata S, Kudo T, Nishihara E, Nishikawa M, Miyauchi A, Akamizu T. Comparison of pathophysiology in subclinical hyperthyroidism with different etiologies. Endocr J 2024; 71:373-381. [PMID: 38296546 DOI: 10.1507/endocrj.ej23-0497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/01/2024] Open
Abstract
Subclinical hyperthyroidism (SHyper) is defined as normal levels of free thyroxine (fT4) and free triiodothyronine (fT3) with suppressed levels of TSH. Previous studies have reported the individual pathophysiology of endogenous SHyper patients and athyreotic patients receiving TSH suppression therapy with levothyroxine; however, apparently no studies have compared the two conditions. Five-hundred-forty untreated endogenous SHyper patients and 1,024 patients receiving TSH suppression therapy who underwent total thyroidectomy for papillary thyroid carcinoma were sampled. Thyroid hormone profiles and peripheral indices related to thyrotoxicosis were investigated in endogenous SHyper patients, athyreotic patients receiving TSH suppression therapy, and healthy participants. Endogenous SHyper patients showed significantly higher thyroid hormone levels (fT4 [p < 0.001] and fT3 [p < 0.001]), and peripheral indices showed a significant tendency towards thyrotoxicosis (strong TSH suppression: alkaline phosphatase [ALP, p < 0.001], creatinine [Cre, p < 0.001], pulse rate [p < 0.05]; and mild TSH suppression: Cre [p < 0.05]) than healthy participants. In contrast, athyreotic patients receiving TSH suppression therapy showed a significant tendency towards thyrotoxicosis than healthy participants only when TSH was strongly suppressed (fT3 [p < 0.001] and Cre [p < 0.001]). Endogenous SHyper patients showed significantly higher fT3 levels (p < 0.001) than athyreotic patients receiving TSH suppression therapy; however, there was a significant tendency towards thyrotoxicosis only when TSH was strongly suppressed (ALP [p < 0.05] and pulse rate [p < 0.05]). The effects of endogenous SHyper and TSH suppression therapy on target organ function are different. Although the serum thyroid hormone profile is similar to that of the thyrotoxic state, athyreotic patients receiving TSH suppression therapy with mildly suppressed serum TSH levels are not thyrotoxic.
Collapse
Affiliation(s)
| | - Mitsuru Ito
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | - Sawako Takahashi
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | - Kazuyoshi Kousaka
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | - Mako Hisakado
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | - Shuji Fukata
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | - Takumi Kudo
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | - Eijun Nishihara
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | | | - Akira Miyauchi
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| | - Takashi Akamizu
- Center for Excellence in Thyroid Care, Kuma Hospital, Kobe 650-0011, Japan
| |
Collapse
|
2
|
Fitzgerald SP, Bean NG, Falhammar H, Hoermann R. Physiological linkage of thyroid and pituitary sensitivities. Endocrine 2023; 79:143-151. [PMID: 36115005 PMCID: PMC9813051 DOI: 10.1007/s12020-022-03184-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/28/2022] [Indexed: 01/09/2023]
Abstract
OBJECTIVES The sensitivities of the pituitary to thyroxine feedback, and the thyroid to thyrotropin stimulation determine the free thyroxine /thyrotropin feedback loop and can be described mathematically by two curves. It is not well understood how the two curves combine in a healthy population with normal thyroid function to express the individual balance points that are observed. This study was directed at this issue testing the possibilities of random combination and directed linkage between the two curves. METHODS We reverse-engineered two sets of population data, on the assumption of independent combinations of thyroid and pituitary sensitivities, to obtain estimates of the curve describing thyroid sensitivity. Sensitivity studies were performed. RESULTS No analysis resulted in a physiologically feasible estimate of the curve describing thyroid sensitivity. There was evidence of linkage of the two curves in terms of their combination throughout the normal range. Thyroid response curves reflecting a low free thyroxine response to thyrotropin tended to be combined in individuals with thyrotropin curves reflecting a high thyrotropin response to free thyroxine, and vice versa. CONCLUSIONS Thyroid and pituitary sensitivities are linked, being combined in individuals in a non-random directed pattern. Direct mutual interaction may contribute to this linkage. This linkage precludes the derivation of the curves describing these sensitivities from population data of the free thyroxine and thyrotropin relationship and complicates their derivation by physiological experimentation. This linkage and probable interaction may also bestow evolutionary advantage by minimising inter-individual variation in free thyroxine levels and by augmenting homeostasis.
Collapse
Affiliation(s)
- Stephen Paul Fitzgerald
- The Departments of General Medicine and Endocrinology, The Royal Adelaide Hospital, Adelaide, SA, Australia.
- The University of Adelaide, School of Medicine, Adelaide, SA, Australia.
| | - Nigel G Bean
- School of Mathematical Sciences and ARC Centre of Excellence for Mathematical and Statistical Frontiers, University of Adelaide, Adelaide, SA, 5000, Australia
| | - Henrik Falhammar
- Department of Endocrinology, Karolinska University Hospital, 171 76, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 171 76, Stockholm, Sweden
| | - Rudolf Hoermann
- Klinikum Lüdenscheid, Paulmannshöherstr. 14, 58515, Lüdenscheid, Germany
- 113 Andersons Road, Yandina, QLD, 4561, Australia
| |
Collapse
|
3
|
Fuse Y, Ito Y, Shishiba Y, Irie M. Gestational trimester-specific reference ranges for serum thyrotropin and free thyroxine in Japanese. Endocr J 2022; 69:1447-1455. [PMID: 35811133 DOI: 10.1507/endocrj.ej22-0237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Thyroid diseases in pregnant and lactating women may result in adverse outcomes for both mothers and infants. A reference range for thyroid function is required in different areas; however, few studies on the gestational change or reference ranges of thyrotropin (TSH) and free thyroxine (FT4) concentrations for Japanese pregnant women have been reported. To establish the gestational trimester-specific reference ranges of serum TSH and FT4 concentrations, our previously published data on 481 pregnant women with the mean age of 30.8 years who provided serum samples as early as gestational week (GW) 6 was compiled by using their percentile values. The overall median urinary iodine concentration (UIC) during pregnancy was 201 μg/L suggesting adequate iodine intake. The prevalence of positive serum thyroid autoantibody (ThAb), i.e., antithyroid peroxidase antibody (TPOAb) and antithyroglobulin antibody (TgAb), was 11.4%. The reference ranges (2.5-97.5th percentile) of serum TSH and FT4 concentration calculated for samples with negative TgAb and TPOAb were 0.04-6.06 mIU/L in the first trimester (T1), 0.31-3.11 mIU/L in the second trimester (T2) and 0.48-3.93 mIU/L in the third trimester (T3) for TSH, and 1.10-1.87 ng/dL (T1), 0.76-1.56 ng/dL (T2) and 0.76-1.14 ng/dL (T3) for FT4. Compared to published data around the world in the 2017 American Thyroid Association (ATA) guideline, both the upper and lower limits of our TSH and FT4 reference ranges in the first trimester were higher than those in other countries. Further research is necessary in larger samples.
Collapse
Affiliation(s)
- Yozen Fuse
- Research Committee on Iodine Related Health Problems, Foundation for Growth Science, Tokyo 113-0033, Japan
| | - Yoshiya Ito
- Research Committee on Iodine Related Health Problems, Foundation for Growth Science, Tokyo 113-0033, Japan
- Division of Clinical Medicine, Japanese Red Cross Hokkaido College of Nursing, Kitami 090-0011, Japan
| | - Yoshimasa Shishiba
- Research Committee on Iodine Related Health Problems, Foundation for Growth Science, Tokyo 113-0033, Japan
| | - Minoru Irie
- Research Committee on Iodine Related Health Problems, Foundation for Growth Science, Tokyo 113-0033, Japan
| |
Collapse
|
4
|
Fitzgerald SP, Bean NG, Hennessey JV, Falhammar H. Thyroid testing paradigm switch from thyrotropin to thyroid hormones-Future directions and opportunities in clinical medicine and research. Endocrine 2021; 74:285-289. [PMID: 34449031 PMCID: PMC8497305 DOI: 10.1007/s12020-021-02851-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/12/2021] [Indexed: 12/26/2022]
Abstract
PURPOSE Recently published papers have demonstrated that particularly in untreated individuals, clinical parameters more often associate with thyroid hormone, particularly free thyroxine (FT4), levels than with thyrotropin (TSH) levels. Clinical and research assessments of the thyroid state of peripheral tissues would therefore be more precise if they were based on FT4 levels rather than on TSH levels. In this paper we describe implications of, and opportunities provided by, this discovery. CONCLUSIONS The FT4 level may be the best single test of thyroid function. The addition of free triiodothyronine (FT3) and TSH levels would further enhance test sensitivity and distinguish primary from secondary thyroid dysfunction respectively. There are opportunities to reconsider testing algorithms. Additional potential thyroidology research subjects include the peripheral differences between circulating FT4 and FT3 action, and outcomes in patients on thyroid replacement therapy in terms of thyroid hormone levels. Previously performed negative studies of therapy for subclinical thyroid dysfunction could be repeated using thyroid hormone levels rather than TSH levels for subject selection and the monitoring of treatment. Studies of outcomes in older individuals with treatment of high normal FT4 levels, and pregnant women with borderline high or low FT4 levels would appear to be the most likely to show positive results. There are fresh indications to critically re-analyse the physiological rationale for the current preference for TSH levels in the assessment of the thyroid state of the peripheral tissues. There may be opportunities to apply these research principles to analogous parameters in other endocrine systems.
Collapse
Affiliation(s)
- Stephen P Fitzgerald
- The Departments of General Medicine and Endocrinology, The Royal Adelaide Hospital, Adelaide, SA, South Australia.
- The University of Adelaide, School of Medicine, Adelaide, SA, Australia.
| | - Nigel G Bean
- School of Mathematical Sciences and ARC Centre of Excellence for Mathematical and Statistical Frontiers, University of Adelaide, Adelaide, SA, Australia
| | - James V Hennessey
- Division of Endocrinology, Department of Medicine Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Henrik Falhammar
- Department of Endocrinology, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Menzies School of Health Research and Royal Darwin Hospital, DARWIN, NT, Australia
| |
Collapse
|
5
|
Duval F, Mokrani MC, Erb A, Danila V, Lopera FG, Foucher JR, Jeanjean LC. Thyroid axis activity and dopamine function in depression. Psychoneuroendocrinology 2021; 128:105219. [PMID: 33839430 DOI: 10.1016/j.psyneuen.2021.105219] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND Several lines of evidence suggest alterations in both hypothalamic-pituitary-thyroid (HPT) axis and dopamine (DA) function in depressed patients. However, the functional relationships between HPT and DA systems have not been well defined. METHODS We examined thyrotropin (TSH) response to 0800 h and 2300 h protirelin (TRH) challenges, and adrenocorticotropic hormone (ACTH), cortisol and growth hormone (GH) responses to apomorphine (APO, a DA receptor agonist), in 58 drug-free DSM-IV major depressed inpatients without a suicidal behavior, and 22 healthy hospitalized controls. RESULTS Compared with controls, patients showed 1) lower basal serum 2300 h-TSH, 2300 h-∆TSH, and ∆∆TSH (difference between 2300 h-∆TSH and 0800 h-∆TSH) levels, and 2) lower cortisol response to APO (∆COR). A negative relationship between ∆∆TSH values and hormonal responses to APO was observed in the depressed group, but not in the control group. When patients were classified on the basis of their ∆∆TSH status, patients with reduced ∆∆TSH values (< 2.5 mU/L) showed hormonal APO responses comparable to those of controls. Patients with normal ∆∆TSH values exhibited lower ∆ACTH, ∆COR, and ∆GH values than patients with reduced ∆∆TSH values and controls. CONCLUSION Taken together, these results suggest that hypothalamic DA function is unaltered in depressed patients with HPT dysregulation (i.e., increased hypothalamic TRH drive leading to altered TRH receptor chronesthesy on pituitary thyrotrophs). Conversely, hypothalamic DA-receptor function is decreased in patients with normal HPT axis activity. These findings are discussed in the context of the role of TRH as a homeostatic neuromodulator in depression.
Collapse
Affiliation(s)
- Fabrice Duval
- APF2R, Rouffach Centre Hospitalier, Pôle 8/9, Rouffach, France.
| | | | - Alexis Erb
- APF2R, Rouffach Centre Hospitalier, Pôle 8/9, Rouffach, France
| | - Vlad Danila
- APF2R, Rouffach Centre Hospitalier, Pôle 8/9, Rouffach, France
| | | | - Jack R Foucher
- iCube, University of Strasbourg, CNRS UMR 7357 FMTS and CEMNIS, Noninvasive Neuromodulation Center, University Hospital Strasbourg, France
| | - Ludovic C Jeanjean
- APF2R, Rouffach Centre Hospitalier, Pôle 8/9, Rouffach, France; iCube, University of Strasbourg, CNRS UMR 7357 FMTS and CEMNIS, Noninvasive Neuromodulation Center, University Hospital Strasbourg, France
| |
Collapse
|
6
|
Duval F, Mokrani MC, Erb A, Gonzalez Opera F, Calleja C, Paris V. Relationship between chronobiological thyrotropin and prolactin responses to protirelin (TRH) and suicidal behavior in depressed patients. Psychoneuroendocrinology 2017; 85:100-109. [PMID: 28843902 DOI: 10.1016/j.psyneuen.2017.07.488] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/17/2017] [Accepted: 07/19/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND So far, investigations of the relationships between suicidality and the activity of the thyrotropic and lactotropic axes are scarce and have yielded conflicting results. METHODS We studied the thyrotropin (TSH) and prolactin (PRL) responses to 0800h and 2300h protirelin (TRH) stimulation tests, carried out on the same day, in 122 euthyroid DSM-5 major depressed inpatients with suicidal behavior disorder (SBD) (either current [n=71], or in early remission [n=51]); and 50 healthy hospitalized controls. RESULTS Baseline TSH and PRL measurements did not differ across the 3 groups. In SBDs in early remission, the TSH and PRL responses to TRH tests (expressed as the maximum increment above baseline value after TRH [Δ]) were indistinguishable from controls. Current SBDs showed (1) lower 2300h-ΔTSH and lower ΔΔTSH values (differences between 2300h-ΔTSH and 0800h-ΔTSH) than controls and SBDs in early remission; and (2) lower baseline free thyroxine (FT4B) levels than controls. In the current SBD group, ΔΔPRL values (differences between 2300h-ΔPRL and 0800h-ΔPRL) were correlated negatively with lethality. Moreover, in current SBDs (1) violent suicide attempters (n=15) showed lower FT4B levels, lower TSH-TRH responses (both at 0800h and 2300h), and lower ΔΔTSH and ΔΔPRL values than controls, while (2) non-violent suicide attempters (n=56) showed lower ΔΔTSH values than controls and higher TSH-TRH responses (both at 0800h and 2300h) than violent suicide attempters. CONCLUSIONS Our results suggest that central TRH secretion is not altered in depressed patients with SBD in early remission. The findings that current SBDs exhibit both decreased FT4B levels and decreased evening TSH responses (and consequently, decreased ΔΔTSH values) support the hypothesis that hypothalamic TRH drive is reduced-leading to an impaired TSH resynthesis in the pituitary during the day after the morning TRH challenge. In violent suicide attempters, the marked abnormalities of TRH test responses might indicate a greatest reduction in hypothalamic TRH drive. These results further strengthen the possibility that a deficit in central TRH function may play a key role in the pathogenesis of suicidal behavior.
Collapse
Affiliation(s)
- Fabrice Duval
- Pôle 8/9 Psychiatry, APF2R, Centre Hospitalier, Rouffach, France.
| | | | - Alexis Erb
- Pôle 8/9 Psychiatry, APF2R, Centre Hospitalier, Rouffach, France
| | | | - Cécile Calleja
- Pôle 8/9 Psychiatry, APF2R, Centre Hospitalier, Rouffach, France
| | - Véronique Paris
- Pôle 8/9 Psychiatry, APF2R, Centre Hospitalier, Rouffach, France
| |
Collapse
|
7
|
Duval F, Mokrani MC, Erb A, Gonzalez Lopera F, Alexa C, Proudnikova X, Butucaru I. Chronobiological hypothalamic-pituitary-thyroid axis status and antidepressant outcome in major depression. Psychoneuroendocrinology 2015; 59:71-80. [PMID: 26036452 DOI: 10.1016/j.psyneuen.2015.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/18/2015] [Accepted: 05/11/2015] [Indexed: 11/21/2022]
Abstract
BACKGROUND We previously demonstrated that the difference between 2300h and 0800h TSH response to protirelin (TRH) tests on the same day (ΔΔTSH test) is an improved measure in detecting hypothalamic-pituitary-thyroid (HPT) axis dysregulation in depression. This chronobiological index (1) is reduced in about three quarters of major depressed inpatients, and (2) is normalized after successful antidepressant treatment. In the present study, we examined whether early changes in HPT axis activity during the first 2 weeks of antidepressant treatment could be associated with subsequent outcome. METHODS The ΔΔTSH test was performed in 50 drug-free DSM-IV euthyroid major depressed inpatients and 50 hospitalized controls. After 2 weeks of antidepressant treatment the ΔΔTSH test was repeated in all inpatients. Antidepressant response was evaluated after 6 weeks of treatment. RESULTS At baseline, ΔΔTSH values were significantly lower in patients compared to controls and 38 patients (76%) showed reduced ΔΔTSH values (i.e., <2.5mU/L). After 2 weeks of antidepressant treatment, 20 patients showed ΔΔTSH normalization (among them 18 were subsequent remitters), while 18 patients did not normalize their ΔΔTSH (among them 15 were non-remitters) (p<0.00001). Among the 12 patients who had normal ΔΔTSH values at baseline, 8 out 9 who had still normal values after 2 weeks of treatment were remitters, while the 3 with worsening HPT axis function (i.e., reduced ΔΔTSH value after 2 weeks of treatment) were non-remitters (p<0.02). A logistic regression analysis revealed that ΔΔTSH levels after 2 weeks of treatment could predict the probability of remission (odds ratio [OR]=2.11, 95% confidence interval [CI]=1.31-3.41). CONCLUSIONS Our results suggest that after 2 weeks of antidepressant treatment: (1) chronobiological restoration of the HPT axis activity precedes clinical remission, and (2) alteration of the HPT axis is associated with treatment resistance.
Collapse
|
8
|
Yan F, Wang Q, Lu M, Chen W, Song Y, Jing F, Guan Y, Wang L, Lin Y, Bo T, Zhang J, Wang T, Xin W, Yu C, Guan Q, Zhou X, Gao L, Xu C, Zhao J. Thyrotropin increases hepatic triglyceride content through upregulation of SREBP-1c activity. J Hepatol 2014; 61:1358-64. [PMID: 25016220 DOI: 10.1016/j.jhep.2014.06.037] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 06/12/2014] [Accepted: 06/30/2014] [Indexed: 01/06/2023]
Abstract
BACKGROUND & AIMS Hallmarks of non-alcoholic fatty liver disease (NAFLD) are increased triglyceride accumulation within hepatocytes. The prevalence of NAFLD increases steadily with increasing thyrotropin (TSH) levels. However, the underlying mechanisms are largely unknown. Here, we focused on exploring the effect and mechanism of TSH on the hepatic triglyceride content. METHODS As the function of TSH is mediated through the TSH receptor (TSHR), Tshr(-/-) mice (supplemented with thyroxine) were used. Liver steatosis and triglyceride content were analysed in Tshr(-/-) and Tshr(+/+) mice fed a high-fat or normal chow diet, as well as in Srebp-1c(-/-) and Tshr(-/-)Srebp-1c(-/-) mice. The expression levels of proteins and genes involved in liver triglyceride metabolism was measured. RESULTS Compared with control littermates, the high-fat diet induced a relatively low degree of liver steatosis in Tshr(-/-) mice. Even under chow diet, hepatic triglyceride content was decreased in Tshr(-/-) mice. TSH caused concentration- and time-dependent effects on intracellular triglyceride contents in hepatocytes in vitro. The activity of SREBP-1c, a key regulator involved in triglyceride metabolism and in the pathogenesis of NAFLD, was significantly lower in Tshr(-/-) mice. In Tshr(-/-)Srebp-1c(-/-) mice, the liver triglyceride content showed no significant difference compared with Tshr(+/+)Srebp-1c(-/-) mice. When mice were injected with forskolin (cAMP activator), H89 (inhibitor of PKA) or AICAR (AMPK activator), or HeG2 cells received MK886 (PPARα inhibitor), triglyceride contents presented in a manner dependent on SREBP-1c activity. The mechanism, underlying TSH-induced liver triglyceride accumulation, involved that TSH, through its receptor TSHR, triggered hepatic SREBP-1c activity via the cAMP/PKA/PPARα pathway associated with decreased AMPK, which further increased the expression of genes associated with lipogenesis. CONCLUSIONS TSH increased the hepatic triglyceride content, indicating an essential role for TSH in the pathogenesis of NAFLD.
Collapse
|
9
|
Tajima T, Nakamura A, Morikawa S, Ishizu K. Neonatal screening and a new cause of congenital central hypothyroidism. Ann Pediatr Endocrinol Metab 2014; 19:117-21. [PMID: 25346914 PMCID: PMC4208260 DOI: 10.6065/apem.2014.19.3.117] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 08/14/2014] [Indexed: 11/20/2022] Open
Abstract
Congenital central hypothyroidism (C-CH) is a rare disease in which thyroid hormone deficiency is caused by insufficient thyrotropin (TSH) stimulation of a normally-located thyroid gland. Most patients with C-CH have low free thyroxine levels and inappropriately low or normal TSH levels, although a few have slightly elevated TSH levels. Autosomal recessive TSH deficiency and thyrotropin-releasing hormone receptor-inactivating mutations are known to be genetic causes of C-CH presenting in the absence of other syndromes. Recently, deficiency of the immunoglobulin superfamily member 1 (IGSF1) has also been demonstrated to cause C-CH. IGSF1 is a plasma membrane glycoprotein highly expressed in the pituitary. Its physiological role in humans remains unknown. IGSF1 deficiency causes TSH deficiency, leading to hypothyroidism. In addition, approximately 60% of patients also suffer a prolactin deficiency. Moreover, macroorchidism and delayed puberty are characteristic features. Thus, although the precise pathophysiology of IGSF1 deficiency is not established, IGSF1 is considered to be a new factor controlling growth and puberty in children.
Collapse
Affiliation(s)
- Toshihiro Tajima
- Department of Pediatrics, Hokkaido University School of Medicine, Sapporo, Japan
| | - Akie Nakamura
- Department of Pediatrics, Hokkaido University School of Medicine, Sapporo, Japan
| | - Shuntaro Morikawa
- Department of Pediatrics, Hokkaido University School of Medicine, Sapporo, Japan
| | - Katsura Ishizu
- Department of Pediatrics, Hokkaido University School of Medicine, Sapporo, Japan
| |
Collapse
|