Prevalence Of Subclinical Hypothyroidism Research Articles

Thyroid function changes during growth hormone therapy in pediatric patients: a controlled study and review of recent data

Introduction: Growth hormone therapy is a cornerstone treatment for children with GHD and ISS. Its impact on the hypothalamic-pituitary-thyroid axis, however, has been a subject of ongoing research. This review compiles findings from several studies spanning three decades and contrasts them with recent data to enhance our understanding of thyroid function dynamics during GH therapy. Review of Literature: Early Observations (1992-2005) Pirazzoli et al. (1992) and Tang et al. (1997) were among the first to document changes in thyroid function due to GH therapy, noting enhanced peripheral conversion of T4 to T3 and a prevalence of subclinical hypothyroidism. Wyatt et al. (1998) reported significant decreases in T4 and increases in T3, indicating a notable shift in thyroid hormone levels early in GH therapy. Mid-Term Studies (2005-2015) Seminara et al. (2005) and Kalina-Faska et al. (2004) reported changes in thyroid function, particularly a decrease in T4 levels and a transient increase in fT3 during the early stages of GH therapy. · Recent Developments (2016-Present) Wang Ying and Liang Furong (2016) emphasized the need for vigilant monitoring of thyroid hormone levels, aligning with Zheng et al. (2014) who noted improvements in lipid metabolism without significant thyroid function impacts. Glynn et al. (2017, 2018) and Kucharska et al. (2021) focused on the complexities of the biological effects of GH-induced changes in thyroid hormones. Comparison with our Data Our recent study reveals subtle changes in thyroid function in GH-treated children with GHD and ISS. We observed a slight decrease in mean FT4 and an increase in mean TSH in the GH treatment group, stable TSH and decreased FT4 in the ISS treatment group, and significant decreases in both FT4 and TSH in the no-treatment group. These findings corroborate the trend seen in earlier studies, highlighting the multifaceted nature of thyroid function changes during GH therapy. Conclusions: The review underscores that GH therapy can significantly influence thyroid function, necessitating regular monitoring of thyroid hormone levels. The variation in thyroid responses suggests a complex interaction between GH therapy and the hypothalamic-pituitary-thyroid axis, which may be influenced by factors like age, severity of GHD, and duration of GH treatment.

Vitamin E Intake and Prevalence Rates of Thyroid Dysfunction and Autoimmune Thyroiditis: A Cross-Sectional Analysis of NHANES Data.

Background: Thyroid disorders are associated with various dietary factors and nutritional elements. The aim of this study was to investigate the relationships between dietary vitamin E intake and the prevalence of thyroid dysfunction and thyroid antibody positivity using data from the National Health and Nutrition Examination Survey (NHANES) database. Methods: Data from the NHANES database collected between 2007 and 2012 were analyzed. A total of 7,773 nonpregnant adults without preexisting thyroid diseases and possessing complete thyroid and vitamin E data were included in the study. The participants were categorized into tertiles based on their dietary vitamin E intake: the lowest group (T1: ≤4.53 mg), the intermediate group (T2: 4.54-8.10 mg), and the highest group (T3: ≥8.11 mg). We used a complex multistage probability sampling design in conjunction with R software. We compared thyroid indices, the prevalence of overt and subclinical hyperthyroidism or hypothyroidism, and the occurrence of thyroid antibody positivity among the three groups based on vitamin E intake. Weighted multinomial logistic regression was used to assess the association between dietary vitamin E intake and thyroid disorders. Restricted cubic splines (RCSs) were used to explore potential nonlinear associations. Results: The prevalence rates of subclinical hypothyroidism (SCH) were 3.63%, 3.07%, and 1.85% in T1, T2, and T3, respectively, indicating a decreasing trend (P-trend = 0.013). In the general population, high vitamin E intake (T3) was significantly associated with a lower prevalence of SCH (OR = 0.28, CI = 0.15-0.54, p < 0.001). Subgroup analysis revealed a more pronounced protective effect in males, with both moderate (T2, OR = 0.45, CI = 0.23-0.87, p = 0.020) and high (T3, OR = 0.19, CI = 0.09-0.39, p < 0.001) dietary vitamin E intake being associated with a lower prevalence of SCH. In addition, moderate (T2, OR = 0.59, CI = 0.37-0.93, p = 0.024) and high (T3, OR = 0.52, CI = 0.36-0.75, p < 0.001) dietary vitamin E intake was associated with a lower prevalence of autoimmune thyroiditis (AIT) in males. However, no significant association was observed among females. Conclusion: The findings of this study suggest that a higher intake of vitamin E is associated with lower prevalence rates of SCH and autoimmune thyroiditis among males.

Prevalence of Thyroid Disorders among Pregnant and Non-Pregnant Women Attending a Tertiary Care Center in Kathmandu

Thyroid hormones are crucial for the overall development of the fetus, and their impact on the pregnancy outcomes needs to be considered seriously. Hence, universal screening for thyroid disorders is recommended in the first trimester of pregnancy. One hundred pregnant women in their first trimester and 100 non-pregnant women of the reproductive age group were screened for thyroid function test. The prevalence of thyroid disorders among the total participants was 32.0% of which 23.5% were hypothyroid and 8.5% were hyperthyroid. Pregnant females had a significantly higher prevalence of thyroid disorders (46.0%) than non-pregnant counterparts (18.0%; P &lt;0.001). Pregnant females had significantly higher odds of hypothyroid disorders than non-pregnant females (OR 3.95; P &lt;0.001). The prevalence of subclinical hypothyroidism among pregnant and non-pregnant was 34.0% and 12.0% respectively which makes it the most common thyroid disorder in both study groups. The median values of FT3, FT4, and TSH levels were, however, not significantly different between the study groups. After adjusting for the confounding effect of age, the odds of thyroid disorders were still significantly higher in pregnant women than in non-pregnant (p =0.001). The prevalence of thyroid disorders, specifically hypothyroidism, is higher in pregnant women compared to non-pregnant counterparts. And this emphasizes on the need of antenatal thyroid screening to be made mandatory in the health policy.

Prevalence and feto-maternal outcomes of subclinical hypothyroidism in pregnancy among mothers attending a tertiary care hospital of Darjeeling District, West Bengal, India

Background: Pregnancy is a stressful test for the mother’s thyroid function. The frequency of hypothyroidism in pregnant women is high. However, there are no adequate studies to evaluate the adverse effects of subclinical hypothyroidism (SCH) during pregnancy. Aims and Objectives: This study was carried out to evaluate the prevalence of SCH in pregnancy and its adverse feto-maternal outcomes among mothers attending a tertiary care teaching hospital in Darjeeling district, West Bengal, India. Materials and Methods: The present study was an institution-based observational descriptive study with a prospective longitudinal design conducted for 1 year among pregnant women attending the antenatal clinic of the study institution in the first trimester of their pregnancy. The sample size for the present study was calculated to be 200. A consecutive sampling technique was utilized. The enrolled women were evaluated for thyroid status by assessing serum thyroid stimulating hormone and free T4 level. All the enrolled mothers were kept under close follow-up and they were evaluated for the development of any antenatal, intranatal, and postnatal complications. Results: The mean age was found to be 23.1±4.2 years, most of the women were nulliparous (60%). Of the women, 74% were euthyroid, while the prevalence of SCH was found to be 16%. On follow-up till the termination of their pregnancies, mothers suffering from SCH had statistically significantly higher incidence of maternal complications such as hypertensive disorders in pregnancy (P=0.001), abortion (P&lt;0.001), postpartum hemorrhage (P=0.020) and also fetal adverse outcomes, such as intrauterine growth restriction (P=0.018), fetal premature birth (P=0.035), and low birth weight (P=0.004) when compared with euthyroid mothers. Conclusion: The burden of SCH high in the study population, and it was significantly associated with a number of different maternal as well as fetal complications and adverse outcomes.

COMPARATIVE ANALYSIS OF THYROID FUNCTION PROFILES BETWEEN POLYCYSTIC OVARY SYNDROME PATIENTS AND HEALTHY CONTROLS: A COMPREHENSIVE STUDY

Objective: To assess the thyroid function status of patients with Polycystic Ovary Syndrome (PCOS) and to compare it with that of healthy women. Methods: This was a descriptive cross-sectional study conducted in the Department of Biochemistry in collaboration with the Department of Obstetrics and Gynecology of a tertiary care hospital in Northern India. 30 patients diagnosed to have polycystic ovarian syndrome on the basis of the Rotterdam criteria were included in this study as cases (Group P). 30 healthy women were enrolled as the control group (Group H). The mean age and marital status of the patients were assessed. The body mass index of all the patients was also determined and compared. Systolic blood pressure, diastolic blood pressure, and pulse rate were also compared. A thyroid function test was done in both groups. The mean triiodothyronine (T3), T4, and thyroid-stimulating hormone (TSH) levels were compared in both groups. p&lt;0.05 was taken as statistically significant. Results: The mean age of patients with PCOS and healthy individuals was 22.10±3.97 years and 23.76±3.97 years, respectively. The mean ages of both groups were found to be comparable in both studies (p=0.1108). The mean body mass index (BMI) of groups P and H was found to be 27.23±5.82 and 23.15±4.12, respectively. The women in group P were found to have a higher BMI as compared to women in group H, and the difference was found to be statistically significant (p=0.0027). The mean pulse rate, systolic blood pressure, and diastolic blood pressure values were found to be comparable. The mean FT3 levels in groups P and H were found to be 3.11±0.88 and 3.13±0.42 ng/mL, whereas the mean free thyroxine levels in groups P and H were found to be 0.96±0.16 and 0.89±0.15, respectively, μg/dL. The mean T3 and T4 levels of both groups were found to be comparable in both groups. However, the mean TSH level in groups P and H was found to be 4.95±2.24 and 2.50±1.19 0.3–4.5 μIU/ml, respectively. The mean TSH level in group P was found to be higher than group H, and the difference was found to be statistically significant (p&lt;0.001). Conclusion: The prevalence of subclinical hypothyroidism was found to be significantly high in women with PCOS, making it necessary to do periodic thyroid function tests in PCOS.

Relationship Between Urinary Iodine Concentration and the Prevalence of Thyroid Nodules and Subclinical Hypothyroidism.

The aim of the study was to investigate the iodine intake in the resident population in Xi'an and analyze the relationship between iodine nutritional status and the prevalence of subclinical hypothyroidism and thyroid nodules (TNs). A total of 2507 people were enrolled in Xi'an. Venous serum thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb), urinary iodine concentration (UIC), and thyroid ultrasonography were collected. Patients with abnormal TSH were checked for free thyroxine (FT4) and triiodothyronine (FT3). Adults in Xi'an had median UICs of 220.80 μg/L and 178.56 μg/l, respectively. A sum of 16.78% of people had subclinical hypothyroidism. Both iodine excess and iodine deficit increased the frequency of subclinical hypothyroidism. The lowest was around 15.09% in females with urine iodine levels between 200 and 299 μg/l. With a rate of 10.69%, the lowest prevalence range for males was 100-199 μg/l. In Xi'an, 11.37% of people have TNs. In comparison to other UIC categories, TN occurrences were higher in females (18.5%) and males (12%) when UIC were below 100 μg/l. In conclusion, iodine intake was sufficient in the Xi'an area, while the adults' UIC remains slightly higher than the criteria. Iodine excess or deficiency can lead to an increase in the prevalence of subclinical hypothyroidism. Patients with iodine deficiency are more likely to develop TNs.

Prevalence of Subclinical Hypothyroidism in Untreated PCOS Patients and PCOS Patients on Metformin at a Tertiary Care Hospital of Eastern India

Prevalence of Subclinical Hypothyroidism in Untreated PCOS Patients and PCOS Patients on Metformin at a Tertiary Care Hospital of Eastern India

Prevalence of Thyroid Dysfunction in Patients with Type 2 Diabetes Mellitus in Mumbai, Maharashtra, India: A Cross-sectional Study

Introduction: India bears a high burden of Type 2 Diabetes Mellitus (T2DM) and Thyroid Dysfunction (TD). Though the coexistence of T2DM and TD has been evaluated, such studies from the perspective of metropolitan cities, including Mumbai, are lacking. Aim: To assess the prevalence of TD in patients with T2DM and to evaluate the association of TD with glycaemic control, duration, and complications of T2DM. Materials and Methods: The present observational cross-sectional study was performed in the Department of General Medicine, The Grant Government Medical College and Sir JJ Group of Hospitals, Mumbai, Maharashtra, India, from January 2016 to December 2017. The study involved 220 diagnosed patients with T2DM, of either gender, aged 18 years or more. All patients were evaluated for TD by performing thyroid profile {T3, T4 and Thyroid Stimulating Hormone (TSH)}. The association of TD prevalence with age, gender, Body Mass Index (BMI), duration of T2DM, Glycated Haemoglobin (HbA1c), and complications was assessed. The qualitative and quantitative parameters were compared with Chi- square and independent sample t-test, respectively, with a p-value &lt;0.05 considered statistically significant. Results: The patients were predominantly males, 127 (57.7%) with a mean±Standard Deviation (SD) age and BMI of 63.4±14.02 years and 25.9±4.5 Kg/m2, respectively. The prevalence of TD was 36.8%. The predominant TD in patients with T2DM was subclinical hypothyroidism (75.9%). TD was significantly associated with advancing age (p-value=0.0167). However, gender and BMI were not significantly associated with TD. Poor glycaemic control was significantly associated with subclinical hypothyroidism (p-value=0.0255). The duration of T2DM was significantly associated with the prevalence of subclinical hypothyroidism (p-value=0.0144), primary hypothyroidism (p-value=0.0257), and subclinical hyperthyroidism (p-value=0.0310). TD was found to be significantly associated with both micro and macrovascular complications of T2DM (all p-values &lt;0.05). Conclusion: In Mumbai, the prevalence of T2DM-associated TD was 36.8%. TD was significantly associated with advancing age, duration of T2DM, high HbA1c levels, and both micro and macrovascular complications.

Subclinical Hypothyroidism in Patients with Obesity and Metabolic Syndrome: A Narrative Review.

The literature on the connection between obesity, metabolic syndrome, and subclinical hypothyroidism is critically analyzed in this narrative review. These conditions are frequently observed among adult populations and various studies and meta-analyses have assessed their association. The prevalence of subclinical hypothyroidism in obese individuals is higher than in non-obese subjects and this trend is more pronounced in unhealthy obesity phenotypes. However, the diagnosis and treatment of subclinical hypothyroidism can be difficult in obese patients. Exaggerated body fat is linked to thyroid hypoechogenicity as evident through ultrasonography and euthyroid obese people have greater TSH, FT3, and FT3/FT4 ratios than non-obese individuals in a euthyroid condition. Moreover, a reduced expression of the TSH receptor and altered function of deiodinases has been found in the adipose tissue of obese patients. Current data do not support the necessity of a pharmacological correction of the isolated hyperthyrotropinemia in euthyroid obese patients because treatment with thyroid hormone does not significantly improve weight loss and the increase in serum TSH can be reversible after hypocaloric diet or bariatric surgery. On the other hand, obesity is linked to elevated leptin levels. Inflammation can raise the risk of Hashimoto thyroiditis, which increases the likelihood that obese patients will experience overt or subclinical hypothyroidism. Both metabolic syndrome and subclinical hypothyroidism are associated with atherosclerosis, liver and kidney disease. Hence, the association of these two illnesses may potentiate the adverse effects noted in each of them. Subclinical hypothyroidism should be identified in patients with obesity and treated with appropriate doses of L-thyroxine according to the lean body mass and body weight. Randomized controlled trials are necessary to verify whether treatment of thyroid deficiency could counteract the expected risks.

Developmental scores in offspring of women with subclinical hypothyroidism in pregnancy are affected by gender and thyrotropin cutoff.

Subclinical hypothyroidism (SCH) is defined by elevated thyrotropin (TSH) and normal level of thyroxine (T4). The definition of SCH and the cutoff for TSH normality in pregnancy are debated. In the present study, we assess offspring perinatal outcome, anthropometrics and early development in relation to different TSH levels. An observational study with 77 singleton-pregnant women included by thyroid screening before a planned cesarean section. Two TSH-cutoffs (3.0 and 3.7 mIU/L) defined euthyroid and SCH groups, and were applied to evaluate offspring anthropometrics, complication rates (maternal blood loss, Apgar-score, cord arterial-pH, admission to neonatal intensive care unit, perinatal hypoglycemia) and offspring development. Development was evaluated by Bayley-III test in a subsample at age 6months (n=27) and 15months (n=22). Prevalence of SCH was 31.2 % at TSH-cutoff 3.0 mIU/L, and 16.9 % at TSH-cutoff 3.7 mIU/L. No differences in complications and anthropometrics were observed. In Bayley-III tests, cognitive score was decreased at 6 months (p=0.012) and at 15months (p=0.056) by applying TSH-cutoff 3.0 mIU/L. At cutoff 3.7 mIU/L, motor score was decreased at 15months (p=0.020). Male offspring had significantly lower cognitive scores at age 6 and 15months (TSH-cutoff 3.0 mIU/L), and motor scores at age 15months (TSH-cutoff 3.7 mIU/L). The importance of the definition of thyroid normality in pregnancy is underlined. This study suggests that a gender-effect might be present in maternal thyroid disease, and that developmental differences exist if TSH-cutoff is low. Further research is needed.

The prevalence of thyroid dysfunction and hyperprolactinemia in women with PCOS.

Ovulatory dysfunction is usually caused by an endocrine disorder, of which polycystic ovary syndrome (PCOS) is the most common cause. PCOS is usually associated with estrogen levels within the normal range and can be characterized by oligo-/anovulation resulting in decreased progesterone levels. It is suggested that decreased progesterone levels may lead to more autoimmune diseases in women with PCOS. In addition, it is often claimed that there is an association between hyperprolactinemia and PCOS. In this large well-phenotyped cohort of women with PCOS, we have studied the prevalence of thyroid dysfunction and hyperprolactinemia compared to controls, and compared this between the four PCOS phenotypes. This retrospective cross-sectional study contains data of 1429 women with PCOS and 299 women without PCOS. Main outcome measures included thyroid stimulating hormone (TSH), Free Thyroxine (FT4), and anti-thyroid peroxidase antibodies (TPOab) levels in serum, the prevalence of thyroid diseases and hyperprolactinemia. The prevalence of thyroid disease in PCOS women was similar to that of controls (1.9% versus 2.7%; P = 0.39 for hypothyroidism and 0.5% versus 0%; P = 0.99 for hyperthyroidism). TSH levels were also similar (1.55 mIU/L versus 1.48 mIU/L; P = 0.54). FT4 levels were slightly elevated in the PCOS group, although within the normal range (18.1 pmol/L versus 17.7 pmol/L; P < 0.05). The prevalence of positive TPOab was similar in both groups (5.7% versus 8.7%; P = 0.12). The prevalence of hyperprolactinemia was similarly not increased in women with PCOS (1.3%% versus 3%; P = 0.05). In a subanalysis of 235 women with PCOS and 235 age- and BMI-matched controls, we found no differences in thyroid dysfunction or hyperprolactinemia. In according to differences between PCOS phenotypes, only the prevalence of subclinical hypothyroidism was significantly higher in phenotype B (6.3%, n = 6) compared to the other phenotypes. Women with PCOS do not suffer from thyroid dysfunction more often than controls. Also, the prevalence of positive TPOab, being a marker for future risk of thyroid pathology, was similar in both groups. Furthermore, the prevalence of hyperprolactinemia was similar in women with PCOS compared to controls.

Trends in Prevalence of Thyroid Dysfunction and its Associations With Mortality Among US Participants, 1988-2012.

Various dynamic factors could influence the prevalence and distribution of thyroid dysfunction. To provide national estimates and temporal trends in prevalence of thyroid dysfunction over the past 3 decades in United States and determine the impact of thyroid dysfunction on mortality in US adults. A cross-sectional analysis of data from 33 117 participants aged 12 years or older in the National Health and Nutrition Examination Survey III (1988-1994), 1999-2002, and 2007-2012. The weighted mean age was 41.6 years, and 48.3% were men. In 2007 through 2012, the prevalence of subclinical and overt hypothyroidism, subclinical and overt hyperthyroidism was 4.3%, 0.33%, 3.2%, and 0.2% respectively. Eighty percent of individuals with thyroid dysfunction were previously undiagnosed. The prevalence of subclinical hypothyroidism and hyperthyroidism was stable, whereas overt hypothyroidism (0.54% [95% CI, 0.35-0.8] vs 0.33% [95% CI, 0.23-0.48]) and hyperthyroidism (0.8% [95% CI, 0.58-1.1] vs 0.2% [95% CI, 0.12-0.33]) were less prevalent in 2007-2012 compared to 1988-1994. Older age, White Americans, obesity, and positivity for thyroid peroxidase antibody and thyroglobulin antibody were risk factors for hypothyroidism, whereas older age, women, and Black Americans were risk factors for hyperthyroidism. Over a median follow-up of 17.2 years, no significant association was observed between any type of thyroid dysfunction with the risk of total or cardiovascular mortality. However, among individuals aged 65 years or older, subclinical hypothyroidism was associated with a higher risk of total mortality (hazard ratio, 1.17; 95% CI, 1.00-1.37; P = .05) and cardiovascular mortality (HR, 1.29; 95% CI, 1.04-1.62; P = .02). The prevalence of subclinical thyroid dysfunction remained relatively unchanged, whereas that of overt thyroid dysfunction decreased. Subclinical hypothyroidism was associated with a higher mortality among individuals aged 65 years or older.

In infertile women with subclinical hypothyroidism, with or without thyroid peroxidase antibodies, serum TSH during pregnancy follows preconception values and thyroid hormones remain stable.

How does subclinical hypothyroidism, defined in infertile women during preconception by thyroid-stimulating hormone (TSH) >2.5 or >4.5 mIU/l, with or without thyroid peroxidase antibodies (anti-TPO) >100 IU/ml, impact thyroid hormone levels during pregnancy and after birth? During pregnancy, TSH levels remain similar to those in preconception, even with supplementary thyroxine, whereas the serum levels of anti-TPO progressively decline. Overt hypothyroidism impacts both pregnancy and offspring but randomized clinical trials and cohort studies failed to detect the benefit of treatment with thyroxine in cases with low-threshold TSH or with anti-TPO during pregnancy. First, the prevalence and reproducibility of two candidate cut-off levels of subclinical hypothyroidism in a cohort of 177 infertile women was compared with 171 women not aiming for pregnancy. Second, the impact of distinct setpoints of TSH in preconception (with or without anti-TPO) was monitored during pregnancy in 87 previously infertile women by high-frequency monitoring of thyroid function. Both studies were carried out from 2007 to 2019. Reproducibility and prevalence of subclinical hypothyroidism were examined in infertile women presenting in the fertility care unit of an academic institution. Women not aiming for pregnancy participated as controls. In both groups, TSH and anti-TPO were measured two times on different occasions. In addition, a group of previously infertile women with known preconception setpoints of TSH (with or without anti-TPO) were followed up prospectively throughout pregnancy and after birth. During pregnancy, serum was sampled weekly until Week 12, then monthly until delivery, and once after birth. Only cases with preconception TSH >4.5 mIU/l were supplemented with thyroxine. After collection of all samples, the serum levels of anti-TPO and the major thyroid hormones were measured. Prolactin with known fluctuations during pregnancy was used as reference. Measures of both TSH and anti-TPO at two different time points were accurate and reproducible. The odds of subclinical hypothyroidism in infertile women and controls were similar. During pregnancy, TSH closely followed preconception TSH levels, whereas serum levels of the thyroid hormones predominantly remained within or above (not below) the reference. Treatment of infertile women with preconception TSH >4.5 mIU/l with thyroxine resulted in higher free thyroxine (fT4) serum levels. The serum levels of anti-TPO declined as pregnancies evolved. The numbers of participants both in the prevalence study and in pregnancy did not reach the a priori estimated numbers. For ethical reasons, the patients with preconception TSH >4.5 mIU/l were treated with thyroxine. The findings apply to infertile women only. We propose to use >4.5 mIU/l as the serum TSH threshold for supplementing women with thyroxine before pregnancy. During pregnancy, fT4 may be the better marker to monitor thyroid function. The consistent decrease of anti-TPO antibody levels during ongoing pregnancies must be considered a protective element. The prevalence part of this study was supported by Merck-Serono, Geneva (TH006/EMR200007-603). The hormone measurements of the serum samples collected during the follow-up pregnancies were made possible by financial support of Roche Diagnostica (November 1721, 2017, Rotkreuz, Switzerland). I.D.G. was supported by a grant of the Repronatal Foundation, Basel, Switzerland. All authors declare no conflict of interest. Research Database of UniBasel, project no. 576691 (2007).

The pleiotropic effects of levothyroxine replacement therapy in patients with subclinical hypothyroidism and hypertension

Background. According to epidemiological studies, the prevalence of subclinical hypothyroidism is about 6 % and it depends on age, gender, region of residence and, at the same time, significantly exceeds the frequency of primary hypothyroidism. Within one year, 5 % of cases of subclinical hypothyroidism turn into the manifested form. Delayed diagnosis of the disease increases the risk of serious complications. It is still controversial whether subclinical hypothyroidism affects blood pressure because of conflicting results in published studies. Thus, the aim of this study was to assess the effects of levothyroxine replacement therapy in patients with subclinical hypothyroidism and hypertension on lipid metabolism, functional state of the endothelium and cognition. Materials and methods. Thirty-one patients with subclinical hypothyroidism and stage 2 hypertension participa­ted in the study, among them 12 (38.71 %) men and 19 (61.29 %) women. The average age of participants was 63.19 ± 1.93 years. The study examined lipid profile, functional state of the endothelium, and cognitive functions based on the results of the Montreal Cognitive Assessment before and after 3 months of additional administration of the levothyroxine replacement thera­py at a dose 25–50 µg daily. Results. The lipid analysis revealed a significant decrease in total cholesterol for 10.08 % (5.54 ± 0.17 mmol/L against 6.23 ± 0.25 mmol/L, Р &lt; 0.05), low-density lipoprotein choleste­rol for 24.5 % (3.39 ± 0.17 mmol/L against 4.49 ± 0.27 mmol/L, Р &lt; 0.01), triglycerides for 19.42 % (1.66 ± 0.11 mmol/L against 2.06 ± 0.16 mmol/L, Р &lt; 0.05) compared to those at baseline. At the same time, patients with subclinical hypothyroidism and hypertension showed a reliable decrease in atherogenic dyslipidemias, 64.52 against 74.19 %. We also observed a reliable improvement of the functional state of the endothelium: the mean value of the endothelium-dependent vasodilation of the brachial artery increased for 11 % (6.56 ± 0.10 % against 5.91 ± 0.05 %, Р &lt; 0.001). The results of the neuropsychological testing showed a reliable improvement of the cognitive functions among examined patients: the average score on the Montreal Cognitive Assessment raised from 23.77 ± 0.60 at baseline to 26.65 ± 0.47 after three months of taking levothyro­xine, Р &lt; 0.001. Conclusions. Levothyroxine replacement therapy in patients with subclinical hypothyroidism and hypertension was followed by a normalization of lipid profile and a decrease in atherogenic dyslipidemias, an improvement of the functional state of the endothelium and state of cognition.

A comparative study on outcomes of fasting vs postprandial thyroid function tests among pregnant mothers in a tertiary care setting in Sri Lanka.

Accurate estimation of serum thyrotropin (TSH) is crucial in the diagnosis of subclinical hypothyroidism (SCH) in pregnancy. We aimed to investigate whether there are significant differences between fasting and nonfasting thyroid function tests (TFTs) among pregnant mothers. We studied 100 pregnant mothers with previously unknown thyroid dysfunction. An equal number of participants were included in each trimester. All pregnant mothers underwent fasting and 2-hour postprandial TFTs (TSH, free T4). Postprandial TSH (mean 1.01 mIU/L, SD 0.80) was significantly lower than the fasting TSH (mean 1.47 mIU/L, SD 1.18) in pregnancy (P < .01). Postprandial free T4 (mean 10.30 pmol/L, SD 2.01) was also lowered compared with fasting free T4 (mean 10.70 pmol/L, SD 1.99) in pregnancy (P < .01). The prevalence of SCH in pregnancy estimated using fasting TSH was 9.4% (SD 3%). In contrast, the prevalence was only 3.5% (SD 2%) when postprandial TSH was used. Compared with the fasting state, postprandial TSH demonstrates a statistically significant reduction that greatly influences the diagnosis of SCH in pregnant mothers. Therefore, we conclude that the timing of sampling for TFTs should be standardized, especially in the pregnant population.

Thyroid function and urinary concentrations of iodine, selenium, and arsenic in vegans, lacto-ovo vegetarians and pescatarians

PurposePopulations following a plant-based diet may be at particular risk of thyroid dysfunction due to low iodine and selenium intakes. The main purpose was to assess thyroid function and urinary concentration of iodine, selenium, and arsenic, in subjects following a vegan, lacto-ovo vegetarian, or pescatarian diet.MethodsIn Norway, a country without mandatory dietary iodine fortification, 205 adults, following vegan (n = 115), lacto-ovo vegetarian (n = 55) and pescatarian diet (n = 35) were included. Thyroglobulin (Tg), thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and serum anti-TPO (S-anti-TPO) were measured in a venous blood sample and concentrations of iodine (UIC), creatinine (UCC), selenium, and arsenic were measured from single spot urine samples.ResultsSubclinical hypothyroidism (TSH > 4.0 mU/L) was observed in 3% of subjects. The overall median (p25, p75) Tg was 17 (9, 30) µg/L and vegans had higher Tg compared to pescatarians. Vegans not consuming iodine-containing supplements (n = 43) had higher Tg, than supplement users (n = 72), 27 (11, 44) vs. 16 (8, 25) µg/L and higher fT4, 16 (15, 17) vs. 15 (14, 17) pmol/L, respectively. The overall median UIC was 57 (28, 130) µg/L, all dietary groups had median UIC below WHO thresholds. Median urinary selenium and arsenic concentration was 13 (6, 22) and 3 (2, 8) µg/L, respectively.ConclusionThe prevalence of subclinical hypothyroidism was low and fT4 and fT3 were within the normal range for all dietary groups. Vegans had significantly increased Tg compared to pescatarians.

Effects of treating subclinical hypothyroidism in pregnancy in India: Are we treating too many for little gain? A retrospective cohort study.

To assess the impact of treatment of subclinical hypothyroidism (SCH) on short-term pregnancy outcomes. Data from 4526 consecutive women with singleton pregnancies who delivered between January 2015 and December 2017 were analyzed. SCH was defined as a thyroid-stimulating hormone (TSH) level between 2.5 and 10 mU/mL with normal free thyroxine. Of those with SCH, some were treated but others were not. These two groups were compared using χ2 and Student t tests for categorical and continuous variables, respectively. Multiple logistic regression models, adjusted for maternal age, body mass index, parity, gestation at TSH measurement, and gestational diabetes mellitus status, were used to investigate the effect of treatment on pregnancy and neonatal outcomes. In all, 1227 (27.1%) of 4526 women had SCH, of whom 393 (32.0%) were treated. The mean age and body mass index were similar in both groups. The mean gestation at measuring of TSH was 11.7 ± 6.5 weeks. There was no significant difference in pregnancy or neonatal outcomes between the two groups. A sub-group analysis when SCH was defined as TSH 4.0 mU/mL or greater showed a higher rate of large for gestational age and lower rates of low birth weight and small for gestational age in the treated group. The prevalence of SCH based on the international guidelines threshold is high in India. Treatment of SCH did not show any difference in pregnancy and neonatal outcomes in this study.

Prevalence of Subclinical Hypothyroidism in Patients with Type II Diabetes Mellitus and Its Impact on Patient's Lipidemic Status?

Prevalence of Subclinical Hypothyroidism in Patients with Type II Diabetes Mellitus and Its Impact on Patient's Lipidemic Status?

Subclinical Hypothyroidism among Patients with COVID-19 Infection in a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Hypothyroidism occurs as a consequence of chronic autoimmune inflammation of the thyroid gland, which occurs due to the reduced function in the secretion of thyroid hormones. The coronavirus disease infection has shown many complications in all organic systems, during the acute phase of infection and in the post-COVID-19 period. SARS-CoV-2 may induce thyroid dysfunction that is usually reversible, including subclinical and atypical thyroiditis. The aim of this study was to find out the prevalence of subclinical hypothyroidism among patients with COVID-19 infection in a tertiary care centre. A descriptive cross-sectional study was conducted in the Department of Internal Medicine of a tertiary care centre from 1 September 2022 to 28 February 2023 after obtaining ethical approval from the Research and Institutional Review Committee (Reference number: 15-079/080). Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated. Among 38 patients with COVID-19, subclinical hypothyroidism was seen among 23 (60.53%) (44.99-76.07, 95% Confidence Interval). The prevalence of subclinical hypothyroidism among COVID-19 patients was found to be similar to other studies done in similar settings. COVID-19; hypothyroidism; thyroid gland.

Prevalence of Subclinical Hypothyroidism in Obese Adults Population

Objective: Determination of frequency of occurrence of subclinical hypothyroidism (SCH) in a local population of obese adults Study design: A cross-sectional study Place and Duration: This study was conducted at Sindh Government Lyari General Hospital Karachi from March 2022 to March2023 Methodology: The patients aged between 18 years to 55 years. All the participants had a body mass index (BMI)of more than 29 kg/m2. As per the exclusion criteria, those patients having kidney failure, liver failure, or already diagnosed with thyroid dysfunction, were not added to the study. Patients taking cholesterol-lowering drugs were also not considered in the study. A blood sample of all the patients was collected for the measurement of serum thyroxine levels and serum thyroid stimulating hormone (TSH) levels. Results: A total of 150 obese adults were considered in the study. The mean age of the participants was 35.7±8.1 years. Overall69 (46%) patients were male while 81 (54%) patients were females. The mean BMI of the patients was 32.1±2.1 kg/m2. The mean serum thyroxine level in the given population was 1.09±0.24 ng/dl and the mean serum TSH level was 3.12±1.09 mIU/L. A total of 24 (16%) patients were detected with subclinical hypothyroidism. Conclusion: Subclinical hypothyroidism is vastly prevalent in the obese adult population, particularly in adults with a BMI of more than 29 kg/m2. However, there is room for further studies to examine the correlation between obesity and SCH. Keywords: Subclinical Hypothyroidism, Obesity, TSH, Thyroxine, Body mass index