We have reviewed the available literature on thyroid diseases and coronavirus disease 2019 (COVID-19), and data from the previous coronavirus pandemic, the severe acute respiratory syndrome (SARS) epidemic. We learned that both SARS and COVID-19 patients had thyroid abnormalities. In the limited number of SARS cases, where it was examined, decreased serum T3, T4 and TSH levels were detected. In a study of survivors of SARS approximately 7% of the patients had hypothyroidism. In the previous evaluation evidence was found that pituitary function was also affected in SARS. Others suggested a hypothalamic-pituitary-adrenal axis dysfunction. One result published recently indicates that a primary injury to the thyroid gland itself may play a key role in the pathogenesis of thyroid disorders in COVID-19 patients, too. Subacute thyroiditis, autoimmune thyroiditis and an atypical form of thyroiditis are complications of COVID-19. Thyroid hormone dysfunction affects the outcome by increasing mortality in critical illnesses like acute respiratory distress syndrome, which is a leading complication in COVID-19. Angiotensin-converting enzyme 2 is a membrane-bound enzyme, which is also expressed in the thyroid gland and the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) uses it for docking, entering as well as replication. Based on the available results obtained in the SARS-CoV-2 pandemic, beside others, we suggest that it is necessary to monitor thyroid hormones in COVID-19.

Serum osteocalcin (OCN) is closely related to metabolic risk factors, and the relationship between OCN and atherosclerosis has been investigated. However, it is still controversial. Herein, we explored the potential correlation between serum total OCN and lower extremity atherosclerotic disease (LEAD) in 326 hospitalized Chinese patients with type 2 diabetes mellitus (T2DM). Femoral intima-media thickness (F-IMT) and lower limb atherosclerotic plaque were assessed through color Doppler ultrasound. Subjects with LEAD had significantly lower serum OCN levels compared with those without LEAD (14.54 [14.10–14.89] ng/mL versus 16.79 [15.86–18.04] ng/mL, p < 0.001). Spearman’s correlation analysis revealed that serum OCN levels were positively associated with high density lipoprotein cholesterol (HDL-C) and negatively associated with fasting plasma glucose (FPG), 2-hour postprandial plasma glucose (2hPG), hemoglobin A1c (HbA1c), waist-to-hip ratio (WHR) and F-IMT. Multiple logistic analysis revealed that OCN (OR 0.938, 95% confidence interval (CI 0.933–0.950, p = 0.003) and glomerular filtration rate (GFR) (OR 0.990, 95% CI 0.985–0.996, p = 0.003) were independently and inversely associated with LEAD, while age (OR 1.140, 95% CI 1.127–1.148, p < 0.001), diabetes duration (OR 1.068, 95% CI 1.039–1.080, p < 0.005) and uric acid (UA) (OR 1.005, 95% CI 1.002–1.007, p = 0.032) were independently and positively associated with LEAD. Additionally, multiple linear regression analysis revealed that serum OCN levels were negatively associated with F-IMT (standardized β = –0.180, p = 0.002). In Chinese patients with T2DM, serum OCN levels were independently and inversely correlated with LEAD.

Propylthiouracil (PTU)-induced otitis media with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) is an extremely rare adverse event associated with anti-thyroid drugs and is not well recognized. A 42-year-old woman with Graves’ disease undergoing PTU therapy for 8 years visited our hospital because of earache and congested feeling in her left ear. Blood tests, a computed tomography scan and pure tone audiometry revealed otitis media and moderate mixed hearing impairment. Antibiotics, ear drops with antibiotics and painkillers were administered. However, her earache and hearing loss gradually got worse and symptoms of facial nerve palsy appeared. At several weeks after initiation of the treatment, a high serum level of myeloperoxidase (MPO)-ANCA, 75.6 U/mL, was revealed. After excluding other causes, she was diagnosed with OMAAV. PTU was suspected as the cause of her OMAAV and was immediately discontinued, and prednisolone was started. Hearing impairment in her left ear gradually got better and showed substantial improvement. Facial nerve palsy disappeared. Although PTU-induced OMAAV is an extremely rare disease, it is important to recognize the disease, as delayed treatment can lead to irreversible hearing loss, hypertrophic pachymeningitis, and subarachnoid hemorrhage. When patients taking anti-thyroid drugs, especially PTU, are diagnosed with refractory otitis media or hearing loss, it is possible that OMAAV might be the cause and thus serum ANCA levels should be evaluated.

Type 2 diabetes (T2D) is a chronic endocrine disorder with rapidly increasing prevalence worldwide. Genetic instability leading to metabolic dysfunction plays an important role in T2D susceptibility and progression. Structural alteration in genome, that is, copy number variation (CNV) is emerging as the inherent marker for disease identification. Previous genomic CNV array revealed that protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene was overlapped with a CNV region, however, whether this CNV affected T2D risk remains to be further elucidated. In this study, we first identified divergent distributions of the PTPN22 copy number (CN) between T2D patients and healthy controls in Chinese population (p < 0.01). Risk assessment analysis revealed that the CN gain (OR = 3.28, p < 0.001) was the promising risk factor for T2D. Also, significantly positive correlations of the PTPN22 CNV with fasting plasma glucose and glycated hemoglobin were demonstrated in T2D patients. Statistical association analysis investigated that the T2D individuals carrying CN gain showed higher plasma glucose and lower insulin levels than those carrying CN normal and loss at 60 min/120 min/180 min during an OGTT test. In addition, the PTPN22 CNV had an effect on total cholesterol, and the CN gain presented higher values than the other two CN types. These results suggested that the CN gain types of the PTPN22 gene accompany with the glycometabolism dysregulation, and finally predispose their carriers to T2D; therefore, the PTPN22 CNV may be a promising biomarker for predicting T2D risk, or a clinical target for T2D diagnosis and therapy.

Autonomous production of adrenocorticotropic hormone (ACTH) from pituitary corticotroph adenomas is the primary cause of Cushing’s disease. Somatostatin receptor, a G protein-coupled receptor (GPCR), types 2 (SSTR2) and 5 (SSTR5) mRNA expression is greater than that of other SSTR subtypes in human corticotroph adenomas. Further, the multiligand SOM230 shows potent effects in decreasing ACTH plasma levels and urinary free cortisol levels in patients with Cushing’s disease. We previously showed that both Sstr2 and Sstr5 mRNA levels were unaffected by SOM230 treatment, suggesting that both receptors might not be downregulated by the agonist. Intracellular molecules, such as β-arrestins, modulate ligand activated-receptor responses. In the present study, we determined regulation of β-arrestin1 and β-arrestin2 by SOM230 and dexamethasone in murine AtT-20 corticotroph tumor cells. In addition, we examined the effects of β-arrestin1 and β-arrestin2 on Sstr mRNA and their protein levels. SOM230 treatment increased β-arrestin1 mRNA levels and did not alter β-arrestin2 mRNA levels. SOM230 treatment could induce β-arrestin1 production in corticotroph tumor cells. Dexamethasone treatment decreased β-arrestin2 mRNA levels. β-arrestin2 knockdown increased proopiomelanocortin, and both Sstr2 and Sstr5 mRNA and their protein levels. The β-arrestin2 knockdown-increased proopiomelanocortin mRNA levels were canceled by SOM230 treatment.

Recent randomized controlled studies have revealed that levothyroxine (LT4) treatment improves pregnancy outcomes only in infertile women with subclinical hypothyroidism who have thyroid autoantibodies (TAs), but not for those with high TSH levels within the normal range who have TAs. Here, we retrospectively investigated pregnancy outcomes in infertile Japanese women with 2.5 μIU/mL ≤ TSH < upper reference limit (URL). Between 2012 and 2018, 286 patients diagnosed with infertility were followed for more than 1 year at our institution. Among them, we included 106 patients with 2.5 μIU/mL ≤ TSH < URL. We divided these patients into four groups based on the combination of TA positivity and LT4 treatment status to assess the effects of LT4 treatment considering TA positivity on the incidence of pregnancy or miscarriage. In this study, we did not find any significant differences in the rates of pregnancy or miscarriage among the four groups (p = 0.81 and 0.52, respectively). In addition, logistic regression analysis showed that age and history of miscarriage were associated with the incidence of pregnancy, but presence of TAs and LT4 treatment status were not and that no variables examined were associated with the incidence of miscarriage. In summary, we were not able to demonstrate the benefit of LT4 treatment for pregnancy outcomes in Japanese euthyroid infertile women with 2.5 μIU/mL ≤ TSH < URL regardless of TA status in this study.

Type 1 diabetes is a chronic metabolic disease characterized by hyperglycemia due to progressive destruction of pancreatic beta cells via autoimmune attack. Meteorin-like protein (metrnl) is a secreted protein homologous to the neurotrophin metrn and it is induced after exercise in the skeletal muscle. In our paper published previously, we showed that the serum level of metrnl was significantly correlated with the lipid profile, glucose profile and insulin resistance. In this experiment, we asked whether intravenous administration of metrnl could delay the onset of diabetes in non-obese diabetic (NOD) mice. 4-week-old NOD mice were injected intravenously with metrnl. Blood glucose levels were measured weekly. Insulitis scoring, intraperitoneal glucose tolerance test, adoptive T cell transfer, flow cytometry analysis and real-time PCR were performed to investigate the underlying mechanism. The results showed that intravenous administration of metrnl delayed the onset of diabetes in NOD mice. Histology of pancreas showed a decreased infiltration of leukocytes, which was in association with augmentation of regulatory T cells, suppression of autoreactive T cells and altered cytokine secretion. To sum up, the present study showed that intravenous administration of metrnl ameliorated islet lymphocyte infiltration and modulated immune cell responses, raising the possibility that it might be beneficial in improving islet function clinically.

We undertook a systematic review and meta-analysis to assess the effects and safety of activators of glucokinase (GKAs) in patients with type 2 diabetes mellitus (T2DM). 11 RCTs, including 2,429 participants, are enrolled in our study. According to different doses, we divided the studies into 3 groups: low-dose group, medium-dose group and high-dose group for subgroup analysis. There were decreases of HbA1c in all dose group (WMD = –0.27, 95%CI (–0.51~ –0.03), Z = 2.17, p = 0.03; WMD = –0.37, 95%CI (–0.58~ –0.16), Z = 3.41, p = 0.0006; WMD = –0.60, 95%CI (–0.86~ –0.33), Z = 4.43, p < 0.00001). Though the total risk of hypoglycemia is absolutely low, in the high-dose group higher hypoglycemia than the placebo can be observed (RR = 0.03, 95%CI (0.00~0.06), Z = 2.27, p = 0.02). In addition, the study found that the drug was less likely to have adverse reactions such as diarrhea, headache and dizziness, nasopharyngitis and upper respiratory tract infection (RR = 0.76, 95%CI (0.36~1.60), Z = 0.73, p = 0.47; RR = 1.26, 95%CI (0.73~2.17), Z = 0.83, p = 0.41; RR = 0.71, 95%CI (0.41~1.22), Z = 1.25, p = 0.21; RR = 1.61, 95%CI (0.77~3.36), Z = 1.26, p = 0.21). It concludes that GKAs are relatively effective and safe in the treatment of patients with T2DM, but in consideration of the potential risk of hypoglycemia in the high-dose group, the low-dose and medium-dose group, in the clinical practice, can be an excellent choice.

A silent pituitary adenoma (SPA) is characterized by the expression of pituitary hormones, detected by immunohistochemical staining, in the absence of clinical signs or symptoms of hormonal excess. Compared with functional pituitary adenomas, little is known regarding the involvement of SPAs in metabolic disorders. This study aimed to examine the correlations between SPAs and metabolic disorders, including obesity, abnormal glucose tolerance, hypertension and dyslipidemia. Seventy-four patients with nonfunctional pituitary adenomas who underwent a pituitary adenomectomy in Hokkaido University Hospital from 2008 to 2016 were retrospectively examined. Pituitary adenomas were immunohistochemically classified into pituitary hormone positive or negative groups. Twenty whole hormone-negative pituitary adenomas were excluded because we couldn’t identify pituitary transcription factors which is necessary for the diagnosis of a null cell adenoma. The preoperative rates of obesity, abnormal glucose tolerance, hypertension and dyslipidemia were compared between each group. Twenty-seven GH positive adenomas (50.0%), 32 gonadotroph positive adenomas (59.3%), 28 TSH positive adenomas (51.9%) and 21 ACTH positive adenomas (38.9%) were identified. Evaluation of the preoperative clinical data showed 25 cases of obesity (46.2%), 16 cases of abnormal glucose tolerance (29.6%), 29 cases of hypertension (53.7%) and 35 cases of dyslipidemia (64.8%). The rate of hypertension was significantly lower in the GH positive group (37.0%) than the GH negative group (70.4%) (p = 0.0140). In the GH negative group, postoperative systolic and diastolic blood pressure levels were significantly lower than preoperative values. GH positive SPAs may affect the homeostasis of blood pressure.

To investigate the acute effects of the coronavirus disease 2019 (COVID-19) on the lifestyle and metabolic parameters in patients with type 2 diabetes mellites. This cross-sectional and retrospective cohort study induced 203 patients who completed a questionnaire regarding stress levels and lifestyles. Data regarding stress levels, sleep time, exercise, and total diet, snack, and prepared food intake were obtained from the questionnaires. The changes in the body weight or HbA1c levels were determined by comparing the values at the time the questionnaire was administered to those noted 3 months ago. Increased levels of stress and decreased exercise levels were reported in approximately 40% and >50%. During the COVID-19 pandemic. There was a negative correlation between stress and exercise (r = –0.285, p < 0.001) and a positive correlation between stress and prepared food intake (r = 0.193, p = 0.009). Decreased exercise levels (r = –0.33, p < 0.001) and increased snack consumption (r = 0.24, p = 0.002) were associated with increased body weight. Furthermore, increased total diet intake (r = 0.16, p = 0.031) was associated with increased HbA1c levels. These relationships remained significant for patients aged <65 years and patients who did not engage in regular exercise. Many patients experienced stress and lifestyle changes due to the COVID-19 pandemic, and these changes were associated with increased body weight and HbA1c levels.

Uterine fibroids and thyroid nodules, both of which are crucially affected by estrogen, are common diseases among reproductive-age women. However, little attention has been paid to the association between the two diseases. This retrospective case-control study aimed to assess the relationships among thyroid nodules, thyroid function and uterine fibroids in China. We reviewed the electronic records of 853 reproductive-age women who attended health check-ups at the Second Affiliated Hospital of Wenzhou Medical University from July 1st, 2017, to June 30th, 2018. All subjects received transvaginal pelvic ultrasound, thyroid ultrasound, thyroid function, and other laboratory tests. We found that the prevalence of thyroid nodules in subjects with uterine fibroids was remarkably higher than that in subjects without fibroids. The proportion of thyroid nodules ≥1 cm in subjects with uterine fibroids was significantly higher than that in subjects without fibroids. Women with thyroid nodules had a higher proportion of multiple uterine fibroids than women without thyroid nodules. Among the parameters of thyroid function, the only statistically significant parameter was total triiodothyronine, i.e., women with uterine fibroids had lower total triiodothyronine levels than unaffected controls; however, the total triiodothyronine levels were within the normal ranges. Moreover, no significant difference was noted in thyroid hormone status between subjects with and without uterine fibroids. Our findings suggest that thyroid nodules are positively correlated with uterine fibroids among reproductive-age women in China. Further studies are needed to confirm this association and fully understand the common pathogenetic mechanism underlying the association between uterine fibroids and thyroid nodules.

Male hypogonadotropic hypogonadism (MHH) is effectively treated by gonadotropins with a high rate of ejaculate sperm and paternity; however, there is no information regarding the appropriate management, including patient-reported outcomes (PROs), of men with MHH who have finished infertility treatment. To compare health-related quality of life, erectile function and biochemical alterations in men with MHH who were treated with testosterone replacement therapy (TRT) or human chorionic gonadotropin (hCG). Twenty-six MHH patients (mean age: 34 years) who needed to improve their androgen deficiency symptoms underwent either hCG therapy (n = 16, started with self-injection of 2,000–7,500 IU per week) or TRT (n = 10, testosterone enanthate 250 mg every 3 weeks). The 36-item Short Form Health Survey (SF-36) questionnaire, five-item International Index of Erectile Function (IIEF-5) and hormonal and biochemical analyses were assessed every 3 months. Changes and comparison of each treatment regarding these parameters were analyzed. Both hCG and TRT significantly improved all domains of the SF-36, except for bodily pain and social functioning. hCG significantly improved the general and mental health domains compared with TRT. Significant improvements in IIEF-5 were observed with both treatments, showing significant improvement with hCG compared to TRT. TRT caused progressive testicular atrophy. There were significant decreases in waist circumference and triglycerides in both treatment groups and significant elevations in prostate-specific antigen and hematocrit. Both hCG and TRT are effective and safe, with preferable PROs by hCG, for treating androgen deficiency in men with MHH who do not need infertility treatment.

Immune-related adverse events in the thyroid glands (thyroid irAEs) during treatment with immune-checkpoint inhibitors (ICIs) are most frequent endocrine irAE. Thyroid irAE can be divided into that requiring continuous therapy for thyroid dysfunction (P-THY), and that requiring only temporal treatment (T-THY). However, predictive factors for those differential outcomes are unknown, and susceptibility of human leukocyte antigen (HLA) to thyroid irAE has never been investigated. This study aimed to elucidate clinical courses and prognosis of P-THY in comparison with T-THY in the aspect of thyroid immunity and HLA. Patients with P-THY (n = 15) that required L-T4 supplemental therapy for hypothyroidism for more than 3 months, and patients with T-THY who required no therapy or therapy within 1 month were enrolled in the study. Lower-value of TSH, higher-value of FT4, and lower value of TSH/FT4 were thought to be predictive markers to estimate P-THY. In addition, anti-thyroglobulin antibody (TgAb) levels were significantly higher in patients with P-THY than those in patients with T-THY. HLA-DPA1*01:03 and HLA-DPB1*02:01 allele, and their haplotype frequencies were significantly higher in patients with P-THY than those in controls. P-THY had better survival rate than T-THY. Pre-existing thyroid autoimmunity, the extent of thyroid dysfunction, and predisposing HLA were associated with the differential course of thyroid irAEs. It was suggested that thyroid function tests, TgAb, and HLA typing tests are useful for prediction of clinical course in thyroid irAEs.

Functional interactions between the levels of clock gene expression and adrenal steroidogenesis were studied in human adrenocortical H295R cells. Fluctuations of Bmal1, Clock, Per2 and Cry1 mRNA levels were found in H295R cells treated with forskolin (FSK) in a serum-free condition. The changes of clock gene expression levels were diverged, with Clock mRNA level being significantly higher than Cry1 and Per2 mRNA levels after 12-h stimulation with FSK. After FSK induction, mRNA levels of StAR and CYP11B2 were highest at 12 hours and CYP17 mRNA level reached a peak at 6 hours, but HSD3B1 mRNA level was transiently decreased at 3 hours. The expression levels of Clock mRNA showed a significant positive correlation with StAR among the interrelationships between mRNA levels of key steroidogenic factors and clock genes. Knockdown of Clock gene by siRNA led to a significant reduction of FSK-induced expression of StAR and CYP17 after 12-h treatment with FSK. BMP-6 and activin, which modulate adrenal steroidogenesis, had inhibitory effects on Clock mRNA expression, whereas treatment with follistatin, a binding protein of activin, increased Clock mRNA levels in the presence of FSK, suggesting an endogenous function of activin in regulation of Clock mRNA expression. Collectively, the results indicated that changes of Clock mRNA expression, being upregulated by FSK and suppressed by BMP-6 and activin, were tightly linked to StAR expression by human adrenocortical cells.