Gestational diabetes and thyroid autoimmunity

Thyroid dysfunction during gestation and gestational diabetes mellitus: a complex relationship

PURPOSE

Gestational diabetes mellitus (GDM) and thyroid dysfunction during gestation (GTD) are the two most prevalent endocrinopathies during pregnancy. The aim of the present review is to provide an overview of the peculiar aspects of GDM and GTD, to highlight the potential interactions and clinical consequences of these two frequent clinical conditions.

METHODS

A literature review regarding GDM and GTD was carried out with particular interest on meta-analyses and human studies dealing with the (i) shared risk factors between GDM and GTD, (ii) the epidemiological link between GTD and GDM, (iii) physiopathologic link between GTD and GDM, (iv) clinical consequences of GDM and GTD, and (v) post-partum implications of GDM and GTD.

RESULTS

The association between GDM and GTD is common and may be explained by the insulin-resistance state due to maternal GTD, to alterations in the placentation process or to the many shared risk factors. Discrepant results of epidemiologic studies can be explained, at least in part, by the changes in diagnostic criteria and screening strategies throughout the years for both conditions. GDM and GTD impact pregnancy outcome and have post-partum long-term consequences, but more studies are needed to prove an additional adverse effect.

CONCLUSIONS

Based on the epidemiological and physio-pathological link between GDM and GTD, it could be suggested that a diagnosis of GTD could lead to screen GDM and the other way round.

Cord blood metabolomics reveals gestational metabolic disorder associated with anti-thyroid peroxidase antibodies positivity

Background

Thyroid disease is one of the common endocrine disorders affecting the pregnant women, in which thyroid autoimmunity can alter the progress and the outcome of pregnancy. Women with euthyroid status but anti-thyroid peroxidase (anti-TPO) antibodies positivity before pregnancy are prone to subclinical gestational hypothyroidism. However, the connections between anti-TPO antibodies positivity and gestational hypothyroidism remain largely unknown. The aim of the present study is to investigate the differences of fetal metabolic profile at birth according to maternal anti-TPO status.

Methods

We performed 1H-NMR metabolomics on cord blood of a nested case control cohort of 22 pregnant women with matched thyroid hormone levels and demographic data, including 11 women with euthyroid status but anti-thyroid antibodies positivity (into the anti-TPO antibodies positivity group) and 11 matched women as controls with euthyroid status and negative anti-thyroid antibodies (into the control group).

Results

Distinct metabolic profiles were observed between the anti-TPO antibody positivity group and the nested control group, from which a total of 10 metabolites with between-group altered abundances were structurally identified. Five out of the 10 metabolites were up-regulated in the anti-TPO antibodies positivity group, including D-Glucose, L-Glutamine, 3-Hydroxybutyric acid, Myo-Inositol, Creatinine. The other 5 metabolites were down-regulated in the anti-TPO antibodies positivity group, including L-Leucine, L-Lysine, L-Glutamic acid, L-Tyrosine, and L-Phenylalanine. All the 10 metabolites have been previously reported to be correlated with hypothyroidism. Metabolite set enrichment analysis and pathway analysis suggested that amino acid metabolism pathways (especially the phenylalanine metabolism) were associated with anti-TPO antibodies positivity.

Conclusion

The results of this study suggested that fetal metabolic disorder is correlated with anti-TPO antibodies positivity, representing by abundance alteration of hypothyroidism associated metabolites and the related disturbance of amino acid metabolism pathways.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04564-8.

Association of thyroid disorders with gestational diabetes mellitus: a meta-analysis

PURPOSE

The current meta-analysis aimed to evaluate the association of thyroid dysfunction and autoimmunity with gestational diabetes mellitus (GDM).

METHODS

A comprehensive search from PubMed, Embase, MEDLINE, and Cochrane databases until November 2020 was conducted. Fixed-effect model was used to combine the results when I² was <50%. Random-effect model was used to summarize the results when I² was >50%.

RESULTS

A total of 44 studies were included in the meta-analysis. Low FT4 levels were closely related with GDM in the first and second trimesters of gestation. Hypothyroxinemia (OR: 1.45; 95% CI: 1.25, 1.68; P < 0.00001), overt (OR: 1.80; 95% CI: 1.73, 1.86; P < 0.00001), and subclinical (OR: 1.54; 95% CI: 1.03, 2.30; P = 0.03) hypothyroidism, overt hyperthyroidism (OR: 1.49; 95% CI: 1.09, 2.04; P = 0.01), and positive thyroid antibodies (OR: 1.49; 95% CI: 1.07, 2.07; P < 0.00001) were observed significantly associated with the risk of GDM. Pregnant women with subclinical hyperthyroidism were less likely to develop GDM (OR: 0.62; 95% CI: 0.39, 0.97; P = 0.04).

CONCLUSIONS

Thyroid dysfunction and positive thyroid antibodies were associated with the risk of GDM. Our findings suggest that pregnant women with these thyroid diseases may be offered screening for GDM comprehensively.

Association of gestational diabetes mellitus and thyroid status during pregnancy: a cross-sectional study in a tertiary health care center of Bangladesh

OBJECTIVE

To find out any association between gestational diabetes mellitus (GDM) and thyroid status (TS) throughout pregnancy in Bangladesh.

METHODOLOGY

This study, designed as a cross-sectional study, was performed on randomly chosen 628 patients attending the Ad-Din Women's Medical College antenatal service from January 1 2019 to December 31 2019. After taking a detailed history, oral glucose tolerance test was done for all the participants. If eligible, then thyroid-stimulating hormone (TSH) and free thyroxine (F.T4) tests were done. t-test and Chi-square test were used to compare variables between various classes as necessary.

RESULTS

The mean gestational age in GDM and non-GDM groups was 20.5 ± 9.1 years and 17.5 ± 9.2 years, which were significantly different (p<.001). There was a substantial (p<.001) high incidence of thyroid disorder (TD) in the non-GDM community. Mean F.T4 of the GDM group was lower in all three trimesters. The mean TSH of the GDM group was more deficient in the early stage of pregnancy but higher in the later stage (3rd trimester). Euthyroid cases were significantly higher (83.8%; p<.001) while subclinical hypothyroidism (9.5%; p<.001) and transient hyperthyroidism (2.4%; p<.001) cases were significantly lower in GDM group.

CONCLUSIONS

Even though GDM and TD are the most prevalent endocrine disorders during pregnancy, neither TS during pregnancy nor any risk factors for TD have been associated with the development of GDM.

Hormonal Regulation of the MHC Class I Gene in Thyroid Cells: Role of the Promoter "Tissue-Specific" Region

In previous studies we have demonstrated that the expression of the Major Histocompatibility Complex (MHC) class I gene in thyrocytes is controlled by several hormones, growth factors, and drugs. These substances mainly act on two regions of the MHC class I promoter a "tissue-specific" region (-800 to -676 bp) and a "hormone/cytokines-sensitive" region (-500 to -68 bp). In a previous study, we have shown that the role of the "tissue-specific" region in the MHC class I gene expression is dominant compared to that of the "hormone/cytokines-sensitive" region. In the present report we further investigate the dominant role of the "tissue-specific" region evaluating the effect of thyroid stimulating hormone (TSH), methimazole (MMI), phenylmethimazole (C10), glucose and thymosin-α1. By performing experiments of electrophoretic mobility shift assays (EMSAs) we show that TSH, MMI and C10, which inhibit MHC class I expression, act on the "tissue-specific" region increasing the formation of a silencer complex. Glucose and thymosin-α1, which stimulate MHC class I expression, act decreasing the formation of this complex. We further show that the silencer complex is formed by two distinct members of the transcription factors families activator protein-1 (AP-1) and nuclear factor-kB (NF-kB), c-jun and p65, respectively. These observations are important in order to understand the regulation of MHC class I gene expression in thyroid cells and its involvement in the development of thyroid autoimmunity.

Assessment of the simultaneous effect of hypothyroidism and thyroid autoimmunity with gestational diabetes on the incidence of type 2 diabetes

INTRODUCTION

Despite the evidence available on the adverse impact of gestational diabetes (GDM) and thyroid disorders on developing type 2 diabetes (T2DM), the concurrent influence of these disorders on the incidence of T2DM has not been reported yet.

METHODS

In this prospective study, 1894 non-diabetic women aged 20 to 60 years, with a history of at least one term delivery, without diagnosed hyperthyroidism were selected at the initiation of the Tehran Thyroid Study (TTS). Pooled logistic regression analyses were used to investigate the association of GDM, thyroid disorders i.e., hypothyroidism and/or thyroid peroxidase antibody (TPOAb) positivity and interaction between GDM and thyroid disorders with the risk of incident T2DM.

RESULTS

Of the 1894 participants of the present study, 346 (18.3%) had a history of GDM, and 832 (43.9%) had thyroid disorders. The total cumulative incidence rate of T2DM at the median follow-up time of ~ 12 years was overall 12/1000 person-years (95% confidence interval (CI): 10/1000-13/1000), with an incidence rate of 16/1000 (95%CI: 13/1000-20/1000) in women with GDM; and 11/100,000 (95%CI: 9/100,000-12/1000) among those without GDM. After adjustment for age, the risk of incident T2DM increased among individuals with the previous GDM compared to women without a history of GDM (odds ratio (OR): 1.54, 95%CI: 1.06, 2.25). No significant associations were found between either thyroid disorders or the interaction between GDM and thyroid disorders with the development of T2DM; (OR: 1.14, 95%CI: 0.82, 1.58) and (OR: 1.27, 95%CI: 0.66, 2.43), respectively.

CONCLUSION

GDM and thyroid disorders have no concurrent impacts on the incidence of T2DM.

Is There Any Relationship Between Thyroid Function Abnormalities, Thyroid Antibodies and Development of Gestational Diabetes Mellitus (GDM) in Pregnant Women?

Objective

To determine the levels of thyroid-stimulating hormone (TSH), thyroxin (T4), triiodothyronine (T3), anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (anti-TG) and renal iodine excretion (RIE) in the first trimester of the pregnancy and to estimate the risk of developing GDM in these patients.

Method

The levels of TSH, T3, T4, anti-TPO, anti-TG, and RIE were retrospectively evaluated. A total of 312 pregnant women were included in the study (GDM (-) group n=240, GDM (+) group n=62). Diagnosis of GDM was made according to the recommendation of American Diabetes Organization (ADA). The association between thyroid dysfunction and GDM was evaluated.

Results

Our study included a total of 302 women. Sixty-two of these women were diagnosed as GDM (62/302=20.5%). When compared with the GDM (-) group the mean TSH level (2.02 vs 4.13 p=0.019), anti-TPO positivity (8.3% vs 30.64% p=0.044), anti-TG positivity (8.3% vs 19.4% p=0.019) and RIE (156 vs 178 p=0.017) were significantly higher in the GDM (+) group. TSH levels were statistically significantly higher in patients with positive anti-TPO levels (P=0.045).

Conclusion

Elevated TSH levels , TPO and TG antibody positivity rates were more frequent among the patients with GDM. These results may be a guide to perform routine thyroid function tests for patients with increased risk of GDM, on the other hand, they will alert the physicians for GDM progression and ensure taking preventive attempts for the patients who have thyroid disorder, especially those with positive thyroid antibodies in the first trimester of the pregnancy.

Isolated effect of maternal thyroid-stimulating hormone, free thyroxine and antithyroid peroxidase antibodies in early pregnancy on gestational diabetes mellitus: a birth cohort study in China

This article aims to understand the isolated effect of maternal thyroid-stimulating hormone (TSH), free thyroxine (FT₄) and antithyroid peroxidase antibodies (TPOAb) in early pregnancy on gestational diabetes mellitus (GDM). Based on a birth cohort, pregnant women presented to maternity hospitals for the first antenatal care from Nov 2008 to Oct 2010 were invited to participate in the study. A self-administered questionnaire was asked to complete to collect data on socio-economic variables, previous adverse pregnancy outcomes, method of conception, previous endocrinic and metabolic diseases, and pregnancy-related anxiety in 1^st trimester of the index pregnancy. Pre-pregnancy BMI was measured. Serum samples were collected, and TSH, FT₄ and TPOAb were assayed. GDM was confirmed from medical records screened on 24-28 gestational weeks by using oral glucose tolerance test (OGTT). The prevalence of isolated subclinical hypothyroidism, hypothyroidemia and positive TPOAb in early pregnancy was 2.0%, 2.0% and 12.8%. Prevalence of GDM in women with the isolated sub-clinical hypothyroidism, hypothyroxinemia and positive TPOAb was 2.9%, 2.8% and 3.1%, respectively, which were all higher than that detected in euthyroidism women (1.2%). Women with isolated positive TPOAb had significantly higher TSH and lower FT₄ level compared with euthyroidism women. It was found that isolated positive TPOAb in early pregnancy increased the risk of GDM, adjusted RR and 95%CI being 2.541(1.037-6.226). No significant relationships were identified between isolated sub-clinical hypothyroidism or hypothyroxinemia with GDM. In conclusion, isolated thyroid autoimmunity, represented by positive TPOAb, in early pregnancy were associated with GDM independent of TSH and FT₄.

Lactation Duration and Long-Term Thyroid Function: A Study among Women with Gestational Diabetes

Lactation is associated with reduced postpartum weight retention and a lower risk of several cardiometabolic disorders in population-based studies. We examined the association between lactation and long-term thyroid function among women with history of gestational diabetes mellitus (GDM), a high-risk population for subsequent metabolic complications. The study included 550 women who developed GDM in the Danish National Birth Cohort (1996–2002) and followed-up in the Diabetes & Women’s Health Study (2012–2014). We assessed adjusted associations between cumulative lactation duration and concentrations of thyroid stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) measured at follow-up. Women with longer cumulative lactation duration tended to have higher fT3 levels (adjusted β and 95% confidence interval (CI) for ≥12 months vs. none: 0.19 (0.03–0.36); p-trend = 0.05). When restricted to women with a single lifetime pregnancy to control for parity (n = 70), women who lactated for >6 months (vs. none) had higher fT3 levels (0.46 pmol/L (0.12–0.80); p-trend = 0.02) and a higher fT3:fT4 ratio (0.61 (0.17–1.05); p-trend = 0.007). Our findings suggested that a longer duration of lactation may be related to greater serum fT3 levels and fT3:fT4 ratio 9–16 years postpartum among Danish women with a history of GDM. The association was particularly pronounced among women who only had one lifetime pregnancy.

Association of Thyroid Dysfunction and Autoimmunity in Pregnant Women with Diabetes Mellitus

Purpose

This study was undertaken to find out the proportion of women with thyroid dysfunction in pregnancy complicated by diabetes mellitus; to find out the association, if any, of thyroid dysfunction and of antithyroid peroxidase (anti-TPO) antibodies during pregnancy in women with pregestational (PGDM) and gestational diabetes mellitus (GDM); and to find out the maternal and perinatal outcomes of pregnancies complicated by both diabetes mellitus and thyroid dysfunction.

Methods

A cross-sectional observational study was conducted in a tertiary care teaching hospital in Kolkata, India, for a period of 1 year. Sixty-four pregnant women with diabetes, both PGDM and GDM, were recruited from the antenatal clinic. They were managed and followed up till 6 weeks postpartum. Their plasma glucose levels were estimated, and thyroid function was evaluated periodically. All relevant data were recorded and analyzed statistically.

Results

Most (81.25%) women had GDM. Forty percent women suffered from some form of thyroid disorder, mostly (37.5%) hypothyroidism. Thyroid dysfunction was not associated with the type of diabetes mellitus (GDM or PGDM) (p > 0.05). The higher rate of anti-TPO titers was observed in pregnancies with PGDM compared to pregnancies with GDM; however, this difference was not statistically associated (p > 0.05). All pregnant women with combined endocrinopathy delivered by cesarean section, and the most common neonatal complication observed was jaundice.

Conclusions

Thyroid disorders are quite common during pregnancy complicated by diabetes mellitus. The study findings warrant routine screening for thyroid abnormalities in diabetic pregnant women. These women have increased rate of maternal and neonatal complications.

Screening of subclinical hypothyroidism during gestational diabetes in Pakistani population

OBJECTIVE

The increased prevalence of adverse effects of altered thyroid functions in pregnancy inspired us to study the frequency of subclinical hypothyroidism (SCH) and the relationship with glycaemic control and foetal weight in pregnant females with and without gestational diabetes mellitus (GDM) in Pakistani population.

PATIENTS AND METHODS

Five hundred and eight pregnant females were enrolled and grouped as per the International Diabetes Association criteria into GDM (n = 208) and healthy control (n = 300). Random blood glucose (RBG), thyroid function tests, anthropometric analysis and foetal ultra sound scans were performed on all study subjects. Data were analysed using Mann-Whitney U test and Chi-square test wherever applicable. Spearman correlation and multiple regression analysis were performed. p values of <0.05 was considered significant.

RESULTS

A total of 61.5% GDM subjects depicted SCH with normal circulating T4 and T3 versus 6.0% healthy controls (p-value < 0.001). Moreover, TSH remained independently associated with RBG (r = 0.109; p < 0.05), poor glycaemic control (r = 0.227; p < 0.001) and negatively associated with foetal growth (r = -0.206; p < 0.001).

CONCLUSION

The detection of high TSH with normal T3 and T4 in females with GDM strongly emphasises the need of thyroid screening as a routine in all antenatal clinics.

Anti thyroperoxidase and anti thyroglobulin antibodies in diabetic pregnancies

INTRODUCTION

Thyroid autoimmunity is very frequent in women of reproductive age and is associated with many adverse pregnancy outcomes; also, diabetes mellitus in pregnancy, of any type, is associated to many complications. In type 1 diabetes, the prevalence of thyroid autoimmunity is higher than in healthy population. Instead, the association of thyroid autoimmunity with other types of diabetes is less clear; however, there are some studies claiming that the prevalence is higher in gestational diabetes too. Poor data about type 2 diabetes in pregnancy are available. It is also unclear how diabetes and thyroid function influence each other and if levothyroxine therapy is necessary in pregnancy with positive autoimmunity but normal thyroid function.

MATERIALS AND METHODS

The aim of this article was to find in the literature studies on thyroid autoimmunity in different types of diabetes in pregnancy, in order to detect any difference in prevalence. Data were found through pubmed database from 1990 to 2013.

CONCLUSIONS

Several studies found a higher prevalence of thyroid autoimmunity in GDM compared to healthy controls; therefore it would be appropriate to extend screening for thyroid diseases to women with GDM. More studies are needed on the possible requirement of therapy for thyroid autoimmunity when the function is normal.

Is autoimmune thyroid dysfunction a risk factor for gestational diabetes?

OBJECTIVE

Some recent studies have related autoimmune thyroid dysfunction and gestational diabetes (GD). The common factor for both conditions could be the existence of pro-inflammatory homeostasis. The study objective was therefore to assess whether the presence of antithyroid antibodies is related to the occurrence of GD.

MATERIAL AND METHODS

Fifty-six pregnant women with serum TSH levels ≥ 2.5 mU/mL during the first trimester were retrospectively studied. Antithyroid antibodies were measured, and an O'Sullivan test was performed. GD was diagnosed based on the criteria of the Spanish Group on Diabetes and Pregnancy.

RESULTS

Positive antithyroid antibodies were found in 21 (37.50%) women. GD was diagnosed in 15 patients, 6 of whom (10.71%) had positive antibodies, while 9 (16.07%) had negative antibodies. Data were analyzed using exact logistic regression by LogXact-8 Cytel; no statistically significant differences were found between GD patients with positive and negative autoimmunity (OR = 1.15 [95%CI = 0.28-4.51]; P=1.00).

CONCLUSIONS

The presence of thyroid autoimmunity in women with TSH above the recommended values at the beginning of pregnancy is not associated to development of GD. However, GD prevalence was higher in these patients as compared to the Spanish general population, suggesting the need for closer monitoring in pregnant women with TSH levels ≥ 2.5 mU/mL.

Endocrine autoimmune diseases and female infertility

An increasing body of evidence suggests that immune-mediated processes affect female reproductive success at multiple levels. Crosstalk between endocrine and immune systems regulates a large number of biological processes that affect target tissues, and this crosstalk involves gene expression, cytokine and/or lymphokine release and hormone action. In addition, endocrine-immune interactions have a major role in the implantation process of the fetal (paternally derived) semi-allograft, which requires a reprogramming process of the maternal immune system from rejection to temporary tolerance for the length of gestation. Usually, the female immune system is supportive of all of these processes and, therefore, facilitates reproductive success. Abnormalities of the female immune system, including autoimmunity, potentially interfere at multiple levels. The relevance of the immune system to female infertility is increasingly recognized by investigators, but clinically is often not adequately considered and is, therefore, underestimated. This Review summarizes the effect of individual autoimmune endocrine diseases on female fertility, and points towards selected developments expected in the near future.