Relationship Between Serum Thyrotropin Levels and Metabolic Diseases in Older Adults.

CONTEXT: Subclinical hypothyroidism is associated with metabolic diseases; however, it remains controversial in older individuals. OBJECTIVE: This work aimed to investigate the relationship between thyrotropin (TSH) levels and metabolic diseases. METHODS: In this cross-sectional study, sampling was conducted from nationally representative general communities from 31 provinces in mainland China. A total of6791 older (aged ≥65 years) and 55 303 young participants (aged 18-64 years) were selected after excluding individuals with overt hyperthyroidism or overt hypothyroidism. According to the kit, TSH reference range (0.27-4.2 mU/L) and the age-specific TSH range previously formulated (an upper limit of 8.86 mU/L for older adults and 6.57 mU/L for young adults), the older adults and young adults were separately divided into 4 groups based on their TSH levels. Main outcome measures included anthropometric assessments, serum concentrations of thyroid functions, and various metabolic parameters. RESULTS: In contrast to young adults, there was no significant increase in the prevalence of any metabolic disorders assessed in the slightly elevated TSH group (TSH 4.21-8.86 mU/L) compared to the euthyroid group (TSH 0.27-4.2 mU/L) among older adults. After adjusting for interference factors, a TSH level higher than 8.86 mU/L was found to be an independent risk factor for low high-density lipoprotein cholesterol (OR, 1.84; 95% CI, 1.14-2.98) and dyslipidemia (OR, 1.49; 95% CI, 1.09-2.04) when compared to the euthyroid group in older adults. CONCLUSION: Slightly elevated TSH levels are not associated with an increased risk of metabolic diseases in older adults. Therefore, we recommend raising the upper limit of the TSH range for individuals aged 65 years and older.

The correlation between iodine and metabolism: a review.

Iodine is involved in the synthesis of thyroid hormones and plays a crucial role in human life. Both iodine deficiency and excess are common issues in certain populations. Iodine also has extrathyroidal effects on organs that can uptake it independently of thyroid hormones. Recently, multiple clinical studies have shown a connection between iodine intake and metabolic disorders, such as metabolic syndrome, obesity, diabetes, hypertension, and dyslipidemia. However, the results of these studies have been inconsistent, and the mechanisms behind these associations are still not well understood. Therefore, in this review, we aim to examine the recent research progress regarding the relationship between iodine and metabolic disorders, along with the relevant mechanisms.

The impact of gut microbiota on autoimmune thyroiditis and relationship with pregnancy outcomes: a review.

Autoimmune thyroiditis (AITD) is a T-cell-mediated, organ- specific autoimmune disease caused by interactions between genetic and environmental factors. Patients with AITD show thyroid lymphocyte infiltration and an increase in the titer of thyroid autoimmune antibodies, thereby altering the integrity of thyroid follicle epithelial cells and dysregulating their metabolism and immune function, leading to a decrease in multi-tissue metabolic activity. Research has shown that patients with AITD have a significantly higher risk of adverse pregnancy outcomes, such as infertility and miscarriage. Levothyroxine(LT4) treatment can improve the pregnancy outcomes of normal pregnant women with thyroid peroxidase antibodies(TPOAb) positivity, but it is not effective for invitro fertilization embryo transfer (IVF-ET) in women with normal thyroid function and positive TPOAb. Other factors may also influence pregnancy outcomes of patients with AITD. Recent studies have revealed that the gut microbiota participates in the occurrence and development of AITD by influencing the gut-thyroid axis. The bacterial abundance and diversity of patients with Hashimoto thyroiditis (HT) were significantly reduced, and the relative abundances of Bacteroides, fecal Bacillus, Prevotella, and Lactobacillus also decreased. The confirmation of whether adjusting the composition of the gut microbiota can improve pregnancy outcomes in patients with AITD is still pending. This article reviews the characteristics of the gut microbiota in patients with AITD and the current research on its impact in pregnancy.

Competing-risks model for predicting the prognostic value of lymph nodes in medullary thyroid carcinoma.

BACKGROUND: Medullary thyroid carcinoma (MTC) is an infrequent form malignant tumor with a poor prognosis. Because of the influence of competitive risk, there may suffer from bias in the analysis of prognostic factors of MTC. METHODS: By extracting the data of patients diagnosed with MTC registered in the Surveillance, Epidemiology, and End Results (SEER) database from 1998 to 2016, we established the Cox proportional-hazards and competing-risks model to retrospectively analyze the impact of related factors on lymph nodes statistically. RESULTS: A total of 2,435 patients were included in the analysis, of which 198 died of MTC. The results of the multifactor competing-risk model showed that the number of total lymph nodes (19-89), positive lymph nodes (1-10,11-75) and positive lymph node ratio (25%-53%,>54%), age (46-60,>61), chemotherapy, mode of radiotherapy (others), tumor size(2-4cm,>4cm), number of lesions greater than 1 were poor prognostic factors for MTC. For the number of total lymph nodes, unlike the multivariate Cox proportional-hazards model results, we found that it became an independent risk factor after excluding competitive risk factors. Competitive risk factors have little effect on the number of positive lymph nodes. For the proportion of positive lymph nodes, we found that after excluding competitive risk factors, the Cox proportional-hazards model overestimates its impact on prognosis. The competitive risk model is often more accurate in analyzing the effects of prognostic factors. CONCLUSIONS: After excluding the competitive risk, the number of lymph nodes, the number of positive and the positive proportion are the poor prognostic factors of medullary thyroid cancer, which can help clinicians more accurately evaluate the prognosis of patients with medullary thyroid cancer and provide a reference for treatment decision-making.

Progress and indication for use of continuous glucose monitoring in patients with diabetes in pregnancy: a review.

Gestational diabetes mellitus is one of the most common endocrine diseases that occur during pregnancy. Disorders of blood glucose metabolism during pregnancy can increase the risk of adverse pregnancy outcomes, such as pregnancy-related hypertension, preeclampsia, eclampsia, miscarriage, macrosomia, and neonatal hypoglycemia. Continuous glucose monitoring (CGM) can safely and effectively monitor blood glucose changes in patients with gestational hyperglycemia, thereby reducing adverse pregnancy outcomes. Hence, this article aimed to provide a comprehensive review of the progress and indications for using CGM in pregnant patients with diabetes. CGM can reduce blood glucose fluctuations and the occurrence of serious hypoglycemia and hyperglycemia events and can provide time in range (TIR). TIR is an important indicator of blood glucose level. Patients with a higher TIR during pregnancy have better gestational outcomes.

Anticardiolipin IgA as a Potential Risk Factor for Pregnancy Morbidity in Patients with Antiphospholipid Syndrome.

BACKGROUND: Antiphospholipid syndrome (APS) is an autoimmune disorder that is characterized by venous or arterial thrombosis and/or obstetric morbidity in the constant presence of persistent antiphospholipid antibodies (aPLs). In patients with APS, the relationship between production of immunoglobulin (Ig)A antiphospholipid antibodies and adverse events in pregnancy is still unclear. As a result of massive trials, the clinical efficiency of IgA-aPLs is used to evaluate pregnancy outcomes in patients with APS. METHODS: We enrolled 381 female patients with APS and 93 healthy pregnant women. Silica clotting time ratio, dilute Russell viper venom time (dRVVT) ratio, and 6 aPLs, including IgA/IgG/IgM isotypes aß2GPI and IgA/IgG/IgM isotypes anticardiolipin (aCL), were detected using commercial kits. RESULTS: We found no significant differences in laboratory parameters between patients with APS and the control group. The total prevalence of aCL IgA was 2.9%; the prevalence of aß2GPI IgA was 3.4%. Only 1.3% of the individuals who tested aCL-positive (5/381) had isolated aCL IgA. Similarly, isolated aß2GPI IgA was present in only 0.8% (3/381) of the aß2GPI-positive subjects. Meanwhile, aCL IgA showed the maximum area under the curve (AUC) of 0.666 (95% CI, 0.60-0.73; P < .001), followed by dRVVT ratio (AUC = 0.649; 0.58-0.72; P < .001). CONCLUSION: Positive aCL IgA and aß2GPI IgA ratios were extremely low for each isolated isotype of aPLs. For patients with APS who experienced fetal loss, aCL IgA may be utilized as a risk factor for pregnancy loss among patients with APS. Establishing a standardized diagnosis of IgA aPLs is also important for these patients.

Reference Intervals for Serum Thyroid-Stimulating Hormone Based on a Recent Nationwide Cross-Sectional Study and Meta-Analysis.

Objective: The aim of our study was to compare the reference intervals (RIs) [median (2.5th-97.5th percentiles)] for thyroid-stimulating hormone (TSH) between subgroups stratified by ethnicity and iodine status in a global context. Design and Methods: Primary data were derived from a recently published cross-sectional study in mainland China. Secondary data were obtained from online databases. The RIs for TSH were calculated in the reference population according to the National Academy of Clinical Biochemistry (NACB) standard and in the disease-free population. A meta-analysis of ethnicity- and iodine status-specific TSH RIs was performed. Results: The primary data showed that the TSH RI (mU/L) in the disease-free population was 2.33 (0.67, 7.87), which is wider than the published RI [2.28 (0.74, 7.04)] in the reference population. The meta-analysis showed that whether in the reference or disease-free population, the RIs in Yellows were much higher than those in Caucasians. In the reference population, the median and 2.5th percentile in the iodine-sufficient subgroup were both lower than the iodine-deficient or more-than-adequate subgroup, while the 97.5th percentile showed a positive trend with increasing sufficiency of iodine. However, in the disease-free population, the iodine-sufficient subgroup had a lower median and 97.5th percentile but higher 2.5th percentile than the iodine-deficient subgroup. Conclusion: Yellows have a higher TSH RI than Caucasians. In the reference population, both the median and 2.5th percentile TSH in the iodine-sufficient population were the lowest among the different iodine status subgroups, while the 97.5th percentile of TSH showed an upward trend with increasing iodine sufficiency.

An Age-Specific Serum Thyrotropin Reference Range for the Diagnosis of Thyroid Diseases in Older Adults: A Cross-Sectional Survey in China.

Background: The fact that serum thyrotropin (TSH) levels increase with age may influence the diagnosis of thyroid diseases in older adults. This study aimed to establish an age-specific serum TSH reference range, examine the prevalence of thyroid diseases in older adults ≥65 years, and analyze the risk factors. Methods: A cross-sectional study of adult populations in 10 cities in China was conducted from 2010 to 2011. A total of 15,008 subjects were randomly selected and completed the present study. Urinary iodine concentration, serum TSH, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) titers were measured. Thyroid ultrasonography and questionnaires were completed by all the subjects. When the TSH level was abnormal, free thyroxine and/or free triiodothyronine levels were measured. Results: When the reference range of the general population was used, the prevalence rates of overt hypothyroidism (Ohypo) and subclinical hypothyroidism (Shypo) in older adults ≥65 years were significantly higher than those in younger adults <65 years (2.09% vs. 0.80% and 19.87% vs. 16.23%, respectively; p < 0.001). Positive TPOAb and positive TgAb were associated with the prevalence of Shypo in older adults. An age-specific serum TSH reference range was formulated according to guidelines set forth by the National Academy of Clinical Biochemistry. Both the median and upper limit values of serum TSH in older adults were higher than those in younger adults (2.58 [0.75-8.86] mIU/L vs. 2.38 [0.76-6.57] mIU/L; p < 0.001). Using the age-specific serum TSH reference range, the prevalence of Shypo in older adults was 3.3%, which was significantly lower than the prevalence based on the reference range of the general population (3.3% vs. 19.87%). The prevalence rates of Ohypo, overt hyperthyroidism (Ohyper), and subclinical hyperthyroidism (Shyper) did not change much (Ohypo: 1.6% vs. 2.09%; Ohyper: 0.7% vs. 0.52%; and Shyper: 3.8% vs. 0.73%). Positive TPOAb, but not positive TgAb, was also associated with the prevalence of Shypo as diagnosed with the age-specific serum TSH reference range. Conclusion: The serum TSH level increases with age, which may represent a normal compensatory phenomenon in older adults ≥65 years. To prevent misdiagnosis and mistreatment, the use of an age-specific serum TSH reference range is recommended in older adults for the diagnosis of thyroid diseases.

Treatment with Iodine in Pregnant Rats with Marginal Iodine Deficiency Improves Cell Migration in the Developing Brain of the Progeny.

Marginal iodine deficiency is a common health problem in pregnant women. Epidemiological and animal studies had shown that marginally maternal iodine deficiency could cause the mild changes of maternal thyroid function, eventually lead to a negative effect on neurodevelopment. But the underlying mechanisms responsible for the neurological impairment remain unclear. The aim of this study is to explore whether marginally maternal iodine deficiency could produce subtle changes in cell migration and cognitive function of offspring, and the optimal time of giving intervention to minimize the adverse effects. In the present study, we established a marginal iodine deficiency model, and iodine supplement was performed on pre-pregnancy (PP), G13 (gestation day 13), and postnatal day 0 (P0). Our data showed that there were changes in the cytoarchitecture and the percentage of bromodeoxyuridine (BrdU)-labeled cells in the cerebral cortex in marginal iodine deficiency rats. The Reelin expression was significantly lower, but Tenascin-C was higher in the cerebral cortex of marginal iodine deficiency group on P7 than the normal group, respectively. When iodine supplement, especially before G13 could reverse the abnormal expression of the two proteins involved in cell migration, which was consistent with the results of Morris Water Maze test. The three intervention groups had shorter escape latencies than the marginal iodine deficiency rats. The earlier that iodine is supplied, the better behavior performance would reach. Our findings suggested that iodine supplement in early stage of pregnancy could improve the cell migration of cerebral cortex and neurodevelopment of offspring.