Obesity is associated with subclinical hypothyroidism in the presence of thyroid autoantibodies: a cross-sectional study

Weight Loss Programs: Why Do They Fail? A Multidimensional Approach for Obesity Management

PURPOSE OF REVIEW

Despite the prevalence of weight loss programs, their success rates remain discouraging, with around half of individuals regaining lost weight within two years. The primary objective of this review is to explore the factors contributing to the failure of weight loss programs and to provide insights into effective weight management strategies.

RECENT FINDINGS

Factors contributing to the failure of weight loss programs include the impracticality of restrictive diets, potential metabolic impacts, limited focus on lifestyle changes, genetic predispositions, psychological influences, socioeconomic status, and medical conditions. A holistic approach considering these factors is crucial for safe and sustainable weight loss. Key findings indicate the importance of holistic approaches to weight management, including lifestyle modifications, medical interventions, and behavioral and psychological strategies. Effective weight loss strategies emphasize low-calorie, nutrient-rich diets, regular physical activity, and interventions tailored to individual needs. Combining multiple approaches offers the best chance of successful weight management and improved health outcomes. This review provides insights into the complexities of obesity management and the factors contributing to the failure of weight loss programs. It highlights the necessity of adopting a holistic approach that addresses dietary habits, physical activity, genetic factors, psychological well-being, and socioeconomic influences. Recommendations include implementing lifestyle modifications, medical interventions when necessary, and integrating behavioral and psychological support to achieve sustainable weight loss and mitigate the global health challenge posed by obesity.

No causal associations of genetically predicted birth weight and life course BMI with thyroid function and diseases

OBJECTIVE

Observational studies have suggested associations of birth weight, childhood BMI, and adulthood BMI with thyroid function or diseases. However, the causal relationships remain unclear due to residual confounding inherent in conventional epidemiological studies.

METHODS

We performed a two-sample Mendelian randomization (MR) study to investigate causal relationships of genetically predicted birth weight, childhood BMI, and adulthood BMI with a range of clinically relevant thyroid outcomes. Additionally, we conducted a reverse MR analysis on adulthood BMI. Data on exposures and outcomes were obtained from large-scale genome-wide association study meta-analyses predominantly composed of individuals of European ancestry.

RESULTS

The MR analysis revealed no evidence of causal associations of birth weight or BMI at different life stages with thyrotropin (TSH) levels, hypothyroidism, hyperthyroidism, autoimmune thyroid disorders, or thyroid cancer. Contrarily, thyroid cancer demonstrated a significant causal relationship with increased adulthood BMI (β = 0.010, 95% CI: 0.006-0.015; p = 5.21 × 10-6).

CONCLUSIONS

Our comprehensive MR did not find causal links of birth weight, childhood BMI, or adulthood BMI with thyroid diseases but provided evidence that thyroid cancer may play a role in weight gain. Our research findings offer valuable insights into the intricate relationship between body weight and thyroid health throughout an individual's life.

Determination of Serum Zinc and Phosphorus Levels in Patients with Hypothyroidism

Various studies reported that serum zinc (Zn) and phosphorus (P) levels altered in patients with hypothyroidism and vice versa, but results were found inconsistent. It was aimed to find the association between serum Zn and P in patients with hypothyroidism. In this case-control study, a total of 100 subjects (50 newly diagnosed patients of hypothyroidism and 50 controls) were enrolled aged between 25 and 60 years. Biochemical parameters such as thyroid profile, serum Zn, and P were estimated in each subject. A p < 0.05 was considered statistically significant. The mean level of body mass index (BMI), thyroid-stimulating hormone (TSH), and serum P was found significantly elevated in cases compared to controls (p < 0.001). However, the mean level of total triiodothyronine (T3), thyroxine (T4), and serum Zn was found significantly reduced in cases compared to controls (p < 0.001). The serum Zn has shown a significant negative correlation with T3 and BMI among cases (r =  - 0.313 p < 0.05, r =  - 0.338 p < 0.05, respectively). However, serum P has shown a significant positive correlation with TSH and BMI among cases (r = 0.310 p < 0.05, r = 0.449 p < 0.01, respectively). Regression analysis indicated that serum Zn significantly predicted hypothyroidism (p < 0.00). Similarly, serum P significantly predicted hypothyroidism (p < 0.007). Results showed that serum Zn levels were significantly reduced and serum P levels were significantly elevated in cases compared to controls. The serum Zn and serum P both significantly associated with hypothyroidism.

Serum Vitamin B12 and Holotranscobalamin Levels in Subclinical Hypothyroid Patients in Relation to Thyroid-Stimulating Hormone (TSH) Levels and the Positivity of Anti-thyroid Peroxidase Antibodies: A Case-Control Study

Background Subclinical hypothyroidism (SCH) is characterized by elevated thyroid-stimulating hormone (TSH) levels, while thyroid hormones (free thyroxine (T4) and free triiodothyronine (T3)) remain within the reference ranges. Vitamin B12 (cobalamin) deficiency is common in patients with autoimmune disorders, including autoimmune hypothyroidism. The study was aimed at evaluating serum vitamin B12 levels and holotranscobalamin (HoloTC) levels in SCH patients and ascertaining their association with a risky level of TSH and the positivity of anti-thyroid peroxidase (anti-TPO) antibodies. Methodology A case-control study was conducted at Azadi Teaching Hospital, Duhok, a city in the Kurdistan region of Iraq, involving 153 participants, including 72 newly diagnosed SCH patients and 81 healthy controls. Serum levels of vitamin B12, HoloTC, TSH, free T4, free T3, and anti-TPO antibodies were measured based on different principles. Results The mean age of patients with SCH was 32.87±8.7 years, with predominantly females comprising 75% and 77.8% being less than 40 years of age. Moreover, the mean levels of serum TSH (6.96±2.68 µIU/L), anti-TPO antibodies (53.31±81.32 IU/ml), and HoloTC (41.93±19.42 pmol/l) were significantly higher in patients with SCH compared to healthy control participants (p < 0.05), whereas there was a non-significantly higher level of vitamin B12(320.72±98.42 pg/ml) among SCH patients compared to healthy control participants (p = 0.220). The mean levels of vitamin B12 (345.33±103.22 pg/ml) and HoloTC (40.14±18.16 pmol/l) were insignificantly lower in SCH patients with TSH levels more than 7 µIU/L (p > 0.05), as well as the mean levels of vitamin B12 (308.82±96.12 pg/ml) and HoloTC (41.14±19.29 pmol/l) insignificantly lower in SCH patients with positive anti-TPO antibodies (p > 0.05).  Conclusions This study highlights the potential association between SCH and altered vitamin B12 status, particularly evident in HoloTC levels. The presence of positive anti-TPO antibodies and the degree of elevation in TSH levels may exacerbate vitamin B12 deficiency in SCH patients.

Impact of methimazole-induced hypothyroidism on postnatal swine

Thyroid hormones regulate metabolic rate, nutrient utilization, growth, and development. Swine are susceptible to thyroid suppression in response to disease or environmental conditions, but the physiological impact of such disruption has not been established. The objective of this study was to evaluate the impact of hypothyroidism induced with the antithyroid medication methimazole (MMI). 10 mg/kg MMI significantly decreased circulating triiodothyronine (T3) for the duration of treatment but had only a transient effect on circulating thyroxine (T4). Thyroid tissue weight was significantly increased by more than 3.5-fold in response to MMI treatment. Histologically, the eosinophilic colloid was largely absent from the thyroid follicle which displayed a disorganized columnar epithelium consistent with goiter. MMI induced hypothyroidism has no effect on growth rate over 28 days. Hepatic expression of genes associated with thyroid metabolism (DIO1, DIO2, and DIO3), lipid utilization (CD36, FASN, and ACACA), apoptosis (TP53, PERP, SIVA1, and SFN) and proliferation (CDK1, CDK2, CDK4, and CDKN1A) were unaffected by treatment. Collectively these results demonstrate that MMI induces mild systemic hypothyroidism and pronounced goiter, indicating a strong homeostatic central regulation within the hypothalamic pituitary thyroid axis. This combined with limited peripheral effects, indicates resilience to hypothyroidism in modern swine.

Causal association between obesity and hypothyroidism: a two-sample bidirectional Mendelian randomization study

Introduction

Previous observational studies have reported a positive correlation between obesity and susceptibility to hypothyroidism; however, there is limited evidence from alternative methodologies to establish a causal link.

Methods

We investigated the causal relationship between obesity and hypothyroidism using a two-sample bidirectional Mendelian randomization (MR) analysis. Single-nucleotide polymorphisms (SNPs) associated with obesity-related traits were extracted from a published genome-wide association study (GWAS) of European individuals. Summarized diagnostic data of hypothyroidism were obtained from the UK Biobank. Primary analyses were conducted using the inverse variance-weighted (IVW) method with a random-effects model as well as three complementary approaches. Sensitivity analyses were performed to ascertain the correlation between obesity and hypothyroidism.

Results

MR analyses of the IVW method and the analyses of hypothyroidism/myxedema indicated that body mass index (BMI) and waist circumference (WC) were significantly associated with higher odds and risk of hypothyroidism. Reverse MR analysis demonstrated that a genetic predisposition to hypothyroidism was associated with an increased risk of elevated BMI and WC, which was not observed between WC adjusted for BMI (WCadjBMI) and hypothyroidism.

Discussion

Our current study indicates that obesity is a risk factor for hypothyroidism, suggesting that individuals with higher BMI/WC have an increased risk of developing hypothyroidism and indicating the importance of weight loss in reducing the risk of hypothyroidism.

Interactions between Polygenetic Variants and Lifestyle Factors in Hypothyroidism: A Hospital-Based Cohort Study

Hypothyroidism is a prevalent endocrine disorder and is associated with a variety of metabolic disturbances. This study aimed to investigate the polygenic variants associated with hypothyroidism risk and the interaction of polygenic risk scores (PRS) with dietary patterns in influencing disease risk in 56,664 participants aged >40 in a hospital-based cohort. The participants were classified as having hypothyroidism (n = 870) diagnosed by a physician and no hypothyroidism (n = 55,794). Genetic variants associated with hypothyroidism were identified using a genome-wide association study (GWAS). Genetic variants interacting with each other were selected using a generalized multifactor dimensionality reduction analysis, and the PRS generated was evaluated for interaction with lifestyle parameters. Coffee, alcohol, meat intake, and a Korean balanced diet were inversely associated with hypothyroidism risk, as were selenium, copper, and manganese intakes. White blood cell (WBC) counts and serum alkaline phosphatase and triglyceride concentrations were positively associated with hypothyroidism risk, as were osteoporosis and thyroid cancer. The GMDR analysis generated a three-single nucleotide polymorphism (SNP) model comprising dual oxidase-1 (DUOX1)_rs1648314; thyroid-stimulating hormone receptor (TSHR)_rs75664963; and major histocompatibility complex, class-II, DQ Alpha-1 (HLA-DQA1)_rs17426593. The PRS derived from the three- and seven-SNP models were associated with a 2.11- and 2.32-fold increase in hypothyroidism risk, respectively. Furthermore, the PRS from the three-SNP model showed interactions with WBC counts, wherein the positive association with hypothyroidism risk was more pronounced in participants with low WBC counts than those with high WBC counts (≥4 × 109 /L). Dietary patterns, such as the plant-based diet (PBD) and the Western-style diet (WSD), along with smoking status, exhibited interactions with the PRS, influencing hypothyroidism risk. In participants with a high PRS, those in the high-PBD, low-WSD, and smoker groups had a higher proportion of hypothyroidism than those in the low-PBD, high-WSD, and non-smoker groups. In conclusion, genetic variants related to immunity and thyroid hormone secretion were linked to hypothyroidism risk, and their PRS interacted with PBD and WSD intake and smoking status. These results contribute to a better understanding of hypothyroidism and its prevention strategies for precision medicine intervention.

Polycystic ovary syndrome and thyroid disorder: a comprehensive narrative review of the literature

Background

Published data on the relationship between polycystic ovary syndrome (PCOS) and thyroid dysfunction are sparse and confusing.

Objective

To comprehensively review data available in the literature regarding the relationship between PCOS and the thyroid function, and its abnormalities.

Methods

Nine main areas of interest were identified and analyzed according to the available evidence: 1) Evaluation of thyroid function for PCOS diagnosis; 2) Epidemiology data on thyroid function/disorders in patients with PCOS, and vice versa; 3) Experimental data supporting the relationship between thyroid function/disorders and PCOS; 4) Effects of thyroid function/disorders on PCOS features, and vice versa; 5) Effect of thyroid alterations on the cardiometabolic risk in women with PCOS; 6) Effect of thyroid abnormalities on reproductive outcomes in women with PCOS; 7) Relationship between thyroid function/abnormalities in patients with PCOS who are undergoing fertility treatment; 8) Effect of treatments for thyroid diseases on PCOS; and 9) Effect of treatments for PCOS on thyroid function. An extensive literature search for specific keywords was performed for articles published from 1970 to March 2023 using PubMed and Web of Science. Data were reported in a narrative fashion.

Results

PCOS is a diagnosis of exclusion for which diagnosis is possible only after excluding disorders that mimic the PCOS phenotype, including thyroid dysfunctions. However, the tests and the cutoff values used for this are not specified. Many experimental and clinical data suggest a relationship between perturbations of the thyroid function and PCOS. Direct and unequivocal evidence on the effects of thyroid function/disorders on PCOS features are lacking. High thyroid-stimulating hormone levels and subclinical hypothyroidism may be associated with significant worsening of several intermediate endpoints of cardiometabolic risk in women with PCOS. Thyroid abnormalities may worsen reproductive outcomes, especially in patients undergoing fertility treatment. To date, there are no data demonstrating the efficacy of thyroid medications on fertility and cardiometabolic risk in women with PCOS. Lifestyle modification changes, metformin, and vitamin D seem to improve thyroid function in the general population.

Conclusion

PCOS and thyroid disorders are closely related, and their coexistence may identify patients with a higher reproductive and metabolic risk. Regular screening for thyroid function and thyroid-specific autoantibodies in women with PCOS, particularly before and during pregnancy, is highly recommended.

Effectiveness of Bariatric Surgery for Improving Thyroid Function and Reducing Levothyroxine Dose in Patients With Obesity and Overt Hypothyroidism

BACKGROUND

 Hypothyroidism is a major hormonal condition that affects more women than men in Saudi Arabia. Studies indicate a bidirectional link between hypothyroidism and obesity, which may improve following bariatric surgery (BS). The focus of this research is to assess how hypothyroidism patients' thyroid function and levothyroxine dosage are impacted by bariatric surgery.

METHODOLOGY

This was an observational retrospective study conducted in two centres at Taif, Saudi Arabia. All morbidly obese patients who were diagnosed with overt hypothyroidism and underwent laparoscopic sleeve gastrectomy from January 2016 to December 2021 were included. The changes in the thyroid profile and the changes in the doses or cessation of levothyroxine were evaluated after the laparoscopic sleeve gastrectomy.

RESULTS

Our results demonstrate that a total of 70 patients dominated by women out of 1202 from both centers who meet our inclusion criteria showed a statistically significant decrease on comparison of clinical parameters (thyroid-stimulating hormone [TSH], free T4 [FT4], free T3 [FT3], levothyroxine [L-T4]) before and after BS. The average TSH levels were determined to be 4.45 ± 4.41 mIU/L prior to BS, and they significantly decreased (3.17 ± 2.77 mIU/L) following BS (p=0.009). When compared to before BS (13.17 ± 2.73 pmol/L), the mean FT4 levels after BS (11.63 ± 5.88 pmol/L) exhibited a significant decline (p=0.046). The mean FT3 levels before and after BS also were statistically significantly lower (1.94 ± 2.12 pg/mL) than before (2.75 ± 1.96 pg/mL), p=0.009. The mean L-T4 levels after BS considerably decreased from before BS (98.68 ± 56.18 mcg) to after BS (79.39 ± 41.49 mcg), p=0.046.

CONCLUSION

Better thyroid profiles and lower levothyroxine dosage show that bariatric surgery improves hypothyroidism.

Potential Association between Subclinical Hypothyroidism and Childhood Migraine

Background and Objectives: Migraine is caused by genetic susceptibility that is triggered by environmental as well as biological factors, and it is also linked to many somatic comorbidities, including clinical and subclinical hypothyroidism. We aimed to estimate the potential association between subclinical hypothyroidism (ScH) and migraine in children at our tertiary hospital. Materials and Methods: Using a case−control strategy, 200 children and adolescents were assigned to two equal groups: a case group (patients with migraine) of 100 patients and a control group of 100 patients without migraine. Clinical and biochemical parameters (TSH, FT4) were compared between the groups using statistical analysis. Results: Thyroid function comparison between the groups showed higher TSH but normal FT4 among children with migraine headache compared to the control group, which means more frequent ScH cases among the migraine group relative to the control (17% vs. 2%, p < 0.001). Obesity and overweight were more frequent among patients with migraine than the control group (8 and 5% vs. 2 and 1%, respectively). The (overweight/obese) patients with migraine had about 77% ScH and 15.4% overt hypothyroidism compared to 8% ScH and no overt hypothyroidism among normal body weight migraine patients (p < 0.001). No significant difference in the prevalence of nodular goiter between patients with migraine and controls was found. Conclusions: Based on our results, subclinical hypothyroidism is significantly linked to childhood migraine. Obesity and being overweight are more frequent among patients with migraine. Therefore, it may be logical to test the thyroid function in migraineur children, especially those with high BMI. Further studies are recommended to discover the mechanism of this association in children.