The Role of Insulin Resistance/Hyperinsulinism on the Rising Trend of Thyroid and Adrenal Nodular Disease in the Current Environment

Machine learning to predict the occurrence of thyroid nodules: towards a quantitative approach for judicious utilization of thyroid ultrasonography

Introduction

Ultrasound is instrumental in the early detection of thyroid nodules, which is crucial for appropriate management and favorable outcomes. However, there is a lack of clinical guidelines for the judicious use of thyroid ultrasonography in routine screening. Machine learning (ML) has been increasingly used on big data to predict clinical outcomes. This study aims to leverage the ML approach in assessing the risk of thyroid nodules based on common clinical features.

Methods

Data were sourced from a Chinese cohort undergoing routine physical examinations including thyroid ultrasonography between 2013 and 2023. Models were established to predict the 3-year risk of thyroid nodules based on patients' baseline characteristics and laboratory tests. Four ML algorithms, including logistic regression, random forest, extreme gradient boosting, and light gradient boosting machine, were trained and tested using fivefold cross-validation. The importance of each feature was measured by the permutation score. A nomogram was established to facilitate risk assessment in the clinical settings.

Results

The final dataset comprised 4,386 eligible subjects. Thyroid nodules were detected in 54.8% (n=2,404) individuals within the 3-year observation period. All ML models significantly outperformed the baseline regression model, successfully predicting the occurrence of thyroid nodules in approximately two-thirds of individuals. Age, high-density lipoprotein, fasting blood glucose and creatinine levels exhibited the highest impact on the outcome in these models. The nomogram showed consistency and validity, providing greater net benefits for clinical decision-making than other strategies.

Conclusion

This study demonstrates the viability of an ML-based approach in predicting the occurrence of thyroid nodules. The findings highlight the potential of ML models in identifying high-risk individuals for personalized screening, thereby guiding the judicious use of ultrasound in this context.

Exploring the advances of single-cell RNA sequencing in thyroid cancer: a narrative review

Thyroid cancer, a prevalent form of endocrine malignancy, has witnessed a substantial increase in occurrence in recent decades. To gain a comprehensive understanding of thyroid cancer at the single-cell level, this narrative review evaluates the applications of single-cell RNA sequencing (scRNA-seq) in thyroid cancer research. ScRNA-seq has revolutionised the identification and characterisation of distinct cell subpopulations, cell-to-cell communications, and receptor interactions, revealing unprecedented heterogeneity and shedding light on novel biomarkers for therapeutic discovery. These findings aid in the construction of predictive models on disease prognosis and therapeutic efficacy. Altogether, scRNA-seq has deepened our understanding of the tumour microenvironment immunologic insights, informing future studies in the development of effective personalised treatment for patients. Challenges and limitations of scRNA-seq, such as technical biases, financial barriers, and ethical concerns, are discussed. Advancements in computational methods, the advent of artificial intelligence (AI), machine learning (ML), and deep learning (DL), and the importance of single-cell data sharing and collaborative efforts are highlighted. Future directions of scRNA-seq in thyroid cancer research include investigating intra-tumoral heterogeneity, integrating with other omics technologies, exploring the non-coding RNA landscape, and studying rare subtypes. Overall, scRNA-seq has transformed thyroid cancer research and holds immense potential for advancing personalised therapies and improving patient outcomes. Efforts to make this technology more accessible and cost-effective will be crucial to ensuring its widespread utilisation in healthcare.

New Insights into the Role of Insulin and Hypothalamic-Pituitary-Adrenal (HPA) Axis in the Metabolic Syndrome

Recent data suggests that (pre)diabetes onset is preceded by a period of hyperinsulinemia. Consumption of the "modern" Western diet, over-nutrition, genetic background, decreased hepatic insulin clearance, and fetal/metabolic programming may increase insulin secretion, thereby causing chronic hyperinsulinemia. Hyperinsulinemia is an important etiological factor in the development of metabolic syndrome, type 2 diabetes, cardiovascular disease, polycystic ovarian syndrome, and Alzheimer's disease. Recent data suggests that the onset of prediabetes and diabetes are preceded by a variable period of hyperinsulinemia. Emerging data suggest that chromic hyperinsulinemia is also a driving force for increased activation of the hypothalamic-adrenal-pituitary (HPA) axis in subjects with the metabolic syndrome, leading to a state of "functional hypercortisolism". This "functional hypercortisolism" by antagonizing insulin actions may prevent hypoglycemia. It also disturbs energy balance by shifting energy fluxes away from muscles toward abdominal fat stores. Synergistic effects of hyperinsulinemia and "functional hypercortisolism" promote abdominal visceral obesity and insulin resistance which are core pathophysiological components of the metabolic syndrome. It is hypothesized that hyperinsulinemia-induced increased activation of the HPA axis plays an important etiological role in the development of the metabolic syndrome and its consequences. Numerous studies have demonstrated reversibility of hyperinsulinemia with lifestyle, surgical, and pharmaceutical-based therapies. Longitudinal studies should be performed to investigate whether strategies that reduce hyperinsulinemia at an early stage are successfully in preventing increased activation of the HPA axis and the metabolic syndrome.

Advantages of Small Incision Surgery in Thyroid Tumors

Objective

Thyroid tumor is a common thyroid disease, and the incidence of complications after traditional thyroid surgery is high, which seriously affects the prognosis of patients. With the development of minimally invasive techniques, small incision surgery has a positive impact on changing the traditional thyroid surgery treatment. However, the gap between small incision surgery and traditional thyroid surgery is unclear, so this meta-analysis was used to evaluate its application value.

Methods

Searching English biomedical databases, including PubMed and Science Network and Chinese major biomedical databases, including CNKI, Wanfang, and Weipu. The keywords of the searched articles are as follows: small incision surgery, traditional thyroid surgery, thyroid tumor treatment, clinical efficacy of thyroid tumor, and surgical treatment, and these keywords are searched individually or in combination to track relevant systematic reviews and literature meta-analysis, and conduct other studies. The retrieval period is from the establishment of the database to January 2022. After extracting the article data, the patients were divided into small incision surgery group and traditional thyroid surgery group due to different intervention methods. The Cochrane risk of bias tool was used to assess the quality of the included literature, and RevMan 5.30 was used for meta-analysis.

Results

A total of 9 articles met the inclusion criteria. There were 369 patients with small incision surgery and 364 patients with traditional thyroid surgery. Compared with traditional thyroid surgery, patients treated with small incision surgery had significant short hospitalization time (MD −2.72, 95% CI (−3.32, −2.12)), less amount of bleeding (MD −15.52, 95% CI (−20.40, −10.65)), short incision length (MD −12.73, 95% CI (−16.29, −9.17)), lower VAS score (MD −2.58, 95% CI (−4.08, −1.08)), and less complications (RR 0.30, 95% CI (0.21, 0.44)).

Conclusion

Compared with traditional thyroid surgery, the results show that small incision surgery can shorten the hospital stay of patients with thyroid tumor, reduce the length of incision, reduce the amount of bleeding and the occurrence of complications, reduce postoperative pain, and have a positive effect on postoperative survival of patients.

Gender-Specific Associations Between Metabolic Disorders and Thyroid Nodules: A Cross-Sectional Population-Based Study from China

Background: Metabolic disorders (MDs) and the metabolic syndrome (MetS) may be associated with thyroid diseases. The aim of this study was to investigate the relationship between MDs and various types of thyroid nodules (TNs), according to gender. Methods: We analyzed cross-sectional data from the Thyroid Disorders, Iodine Status, and Diabetes Epidemiological (TIDE) survey in China. A total of 56,729 subjects ≥18 years of age were included. Thyroid gland morphology was assessed by thyroid standardized ultrasonography. A multivariate logistic regression model was used to explore the odds ratio (OR) and confidence intervals [CIs] for any associations between MDs and TNs. Subgroup analyses were conducted according to gender and TN type (solitary, S-TN; multiple, M-TNs). Results: The prevalence of TNs was increased in several MDs, and was higher in women than men regardless of whether they suffered from MDs (22.0%, CI [21.6-22.5%] vs. 15.7%, CI [15.3-16.7%], p < 0.001). TNs were associated with the presence of MDs (OR = 1.189, CI [1.107-1.278], p < 0.001), hypercholesterolemia (OR = 1.235, CI [1.177-1.296], p < 0.001), high low-density lipoprotein cholesterol (LDL-C; OR = 1.249, CI [1.186-1.316], p < 0.001), and hyperuricemia (OR = 1.206, CI [1.126-1.293], p < 0.001). MDs and MetS were, respectively, significantly associated with TNs, S-TNs, and M-TNs in men, while MDs were significantly associated with the three TN profiles in women. With respect to dyslipidemia, hypercholesterolemia and high LDL-C had the strongest association with TNs, whereas hypertriglyceridemia had no effect. Conclusions: TNs (especially M-TNs) may be associated with MDs and their various components, and there appear to be some gender-specific associations.

Long delay in diagnosis of a case with MEN1 due to concomitant presence of AIMAH with insulinoma: a case report and literature review

BACKGROUND

ACTH-independent macronodular hyperplasia (AIMAH) is an uncommon disorder characterized by massive enlargement of both adrenal glands and hypersecretion of cortisol. Concomitant AIMAH and multiple endocrine neoplasia type1 (MEN1) is rare to our knowledge.

CASE PRESENTATION

Herein, we describe a 32 year old woman with long history of prolactinoma and secondary ammonhrea presented with not-severe manifestation of hypoglycemia due to concomitant presence of insulinoma with AIMAH leading to 12 years delay of MEN1 diagnosis. Laboratory tests showed severe hypoglycemia associated with hyper insulinemia (non-fasting blood sugar = 43 mg/dl, insulin = 80.6 μIU /ml, C-peptide = 9.3 ng/ml) hyperparathyroidism (calcium = 10.3 mg/dl, phosphor = 3.1 mg/dl, PTH = 280 pg/ml) and chemical evidence of an ACTH-independent hypercortisolism (serum cortisol value of 3.5, after 1 mg dexamethasone suppression test serum ACTH value of 17 pg/ml, and high urinary cortisol level). Abdominal CT scan demonstrated two enhancing well-defined masses 27*20 mm and 37*30 mm in the tail and body of the pancreas, respectively, and a 36*15 mm mass in left adrenal gland (seven Hounsfield units). Dynamic pituitary MRI revealed a partial empty sella. The physical examination of the patient was unremarkable. Distal pancreatectomy and a left adrenalectomy were performed. After the surgery, we observed clinical and biochemical remission of hyper insulinemia and gradual decrease in urinary cortisol. The histological features of the removed left adrenal gland were consistent with AIMAH. Histological examination of the pancreatic lesions revealed well differentiated neuroendocrine tumors. Genetic abnormalities in the MEN1, heterozygote for pathogenic variant chr11; 645,773,330-64577333AGAC, c.249-252delGTCT, p. (11e85Serfs Ter33) in exon 2 were found. It was recommended the patient undergoes parathyroidectomy as soon as possible.

CONCLUSION

Given the history and presentation of our case, we recommend that the clinicians consider the possibility of autonomous cortisol production in MEN1 patients who do not show severe symptoms of hypoglycemia in the presence of insulinoma.

Impaired Glucose Metabolism, Anti-Diabetes Medications, and Risk of Thyroid Cancer

Simple Summary

An epidemiologic link exists between obesity, insulin resistance, diabetes, and some cancers, such as breast cancer and colon cancer. The prevalence of obesity and diabetes is increasing, and additional epidemiologic data suggest that there may be a link between obesity and risk of thyroid abnormalities. Factors that may link obesity and diabetes with thyroid proliferative disorders include elevated circulating levels of insulin, increased body fat, high blood sugars, and exogenous insulin use. However, mechanisms underlying associations of obesity, diabetes, and thyroid proliferative disorders are not yet fully understood. The present manuscript reviews and summarizes current evidence of mechanisms and epidemiologic associations of obesity, insulin resistance, and use of anti-diabetes medications with benign and malignant proliferative disorders of the thyroid.

Abstract

The prevalence of obesity is progressively increasing along with the potential high risk for insulin resistance and development of type 2 diabetes mellitus. Obesity is associated with increased risk of many malignancies, and hyperinsulinemia has been proposed to be a link between obesity and cancer development. The incidence of thyroid cancer is also increasing, making this cancer the most common endocrine malignancy. There is some evidence of associations between obesity, insulin resistance and/or diabetes with thyroid proliferative disorders, including thyroid cancer. However, the etiology of such an association has not been fully elucidated. The goal of the present work is to review the current knowledge on crosstalk between thyroid and glucose metabolic pathways and the effects of obesity, insulin resistance, diabetes, and anti-hyperglycemic medications on the risk of thyroid cancer development.

Does insulin resistance trigger thyroid nodule?

The relationship between insulin resistance and thyroid nodules is not clearly understood. The purpose of this study is to investigate the relationship between insülin resistance and thyroid nodules in non-diabetic patients. 410 patients who applied to the Internal Medicine outpatient clinic from June 2018 to July 2019 were reviewed retrospectively. A total of 216 non-diabetic patients were divided into two groups. The relationship of 105 patients with thyroid nodules and 110 patients without thyroid nodules with insulin resistance was investigated. Homeostasis model assessment of insulin resistance value, serum triglycerides and total cholesterol level, and the ratio of women were higher in the group with thyroid nodules (p < 0.05). There was a positive and significant relationship between homeostasis model assessment of insulin resistance value and thyroid nodules (r + 0.29, p < 0.05). In non-diabetic thyroid nodule patients, a significant relationship was detected between nodule formation and insulin resistance. However, these data must be confirmed by other studies in the future.

Prevalence and associated metabolic factors for thyroid nodules: a cross-sectional study in Southwest of China with more than 120 thousand populations

OBJECTIVE

To explore the prevalence and its associated metabolic factors of thyroid nodules (TNs) among subjects who participated in the physical examinations in Chongqing, China.

METHODS

The participants from the Health Management Center of JinShan Hospital of Chongqing Medical University, between September 2015 and May 2020, were included in this study. All of the participants underwent thyroid ultrasonography, anthropometric measurements, and serum examinations. Differences in the TNs prevalence were compared with the chi-square test or Wilcoxon rang-sum test. Multivariable logistic regression analyses were used to estimate the metabolic factors associated with TNs and multiple thyroid nodules (MTNs).

RESULTS

Of the included 121,702 participants, 41,547 had TNs, and 20,899 had MTNs, with the prevalence of 34.1 and 17.0 %, respectively. Women had a significantly higher prevalence of TNs than men (40.6 % vs. 29.8 %; χ² = 1517.33, P < 0.001), and TNs prevalence was gradually increased with age (P for trend < 0.001). Female gender, advanced age, and metabolic factors including central obesity, hypertension, diabetes and fatty liver were positively associated with TNs; BMI, hyperlipoidemia and hyperuricemia were not independent risk factors of TNs. While female gender, advanced age, central obesity, hypertension and diabetes were independent risk factors of MTNs.

CONCLUSIONS

The prevalence of thyroid nodules was relatively high. The associated factors identified in this study could help the clinicians to detect the high-risk patients and make targeted screening strategies for the preventing of the occurrence of TNs.

A breakthrough-like effect of metformin reduces peripheral resistance to triiodothyronine in euthyroid, non-insulin-resistant, type 2 diabetic patients

BACKGROUND

Type 2 diabetes is characterized, beyond the insulin resistance, by polyhormonal resistance. Thyroid hormonal resistance has not yet been described in this population of patients. Metformin is used to decrease insulin resistance, and at present, it is assumed to influence the effect of triiodothyronine, as well.

METHODS

In this open-label, pilot, hypothesis-generating, follow-up study, 21 patients were included; all of them were euthyroid with drug naïve, newly diagnosed type 2 diabetes. Before and after 4 weeks of metformin therapy, fructosamine, homeostasis model assessment for insulin resistance (HOMA-IR), thyroid hormones, T3/T4 ratio, and TSH, as well as blood pressure and heart rate using ambulatory blood pressure monitor were measured. We also conducted an in vitro study to investigate the possible mechanisms of T3 resistance, assessing T3-induced Akt phosphorylation among normal (5 mM) and high (25 mM) glucose levels with or without metformin treatment in a human embryonal kidney cell line.

RESULTS

Metformin decreased the level of T3 (P < 0.001), the ratio of T3/T4 (P = 0.038), fructosamine (P = 0.008) and HOMA-IR (P = 0.022). All these changes were accompanied by an unchanged TSH, T4, triglyceride, plasma glucose, bodyweight, blood pressure, and heart rate. In our in vitro study, T3-induced Akt phosphorylation decreased in cells grown in 25 mM glucose medium compared to those in 5 mM. Metformin could not reverse this effect.

CONCLUSION

Metformin seems to improve T3 sensitivity in the cardiovascular system in euthyroid, type 2 diabetic patients, the mechanism of which may be supracellular.

Autoregulation of insulin receptor signaling through MFGE8 and the αvβ5 integrin

The role of integrins, in particular αv integrins, in regulating insulin resistance is incompletely understood. We have previously shown that the αvβ5 integrin ligand milk fat globule epidermal growth factor like 8 (MFGE8) regulates cellular uptake of fatty acids. In this work, we evaluated the impact of MFGE8 on glucose homeostasis. We show that acute blockade of the MFGE8/β5 pathway enhances while acute augmentation dampens insulin-stimulated glucose uptake. Moreover, we find that insulin itself induces cell-surface enrichment of MFGE8 in skeletal muscle, which then promotes interaction between the αvβ5 integrin and the insulin receptor leading to dampening of skeletal-muscle insulin receptor signaling. Blockade of the MFGE8/β5 pathway also enhances hepatic insulin sensitivity. Our work identifies an autoregulatory mechanism by which insulin-stimulated signaling through its cognate receptor is terminated through up-regulation of MFGE8 and its consequent interaction with the αvβ5 integrin, thereby establishing a pathway that can potentially be targeted to improve insulin sensitivity.

Bone Marrow-Derived Mesenchymal Stem Cells Restored High-Fat-Fed Induced Hyperinsulinemia in Rats at Early Stage of Type 2 Diabetes Mellitus

Numerous studies have proposed the transplantation of mesenchymal stem cells (MSCs) in the treatment of typical type 2 diabetes mellitus (T2DM). We aimed to find a new strategy with MSC therapy at an early stage of T2DM to efficiently prevent the progressive deterioration of organic dysfunction. Using the high-fat-fed hyperinsulinemia rat model, we found that before the onset of typical T2DM, bone marrow-derived MSCs (BM-MSCs) significantly attenuated rising insulin with decline in glucose as well as restored lipometabolic disorder and liver dysfunction. BM-MSCs also favored the histological structure recovery and proliferative capacity of pancreatic islet cells. More importantly, BM-MSC administration successfully reversed the abnormal expression of insulin resistance-related proteins including GLUT4, phosphorylated insulin receptor substrate 1, and protein kinase Akt and proinflammatory cytokines IL-6 and TNFα in liver. These findings suggested that MSCs transplantation during hyperinsulinemia could prevent most potential risks of T2DM for patients.

The prevalence and characteristics of non-functioning and autonomous cortisol secreting adrenal incidentaloma after patients' stratification by body mass index and age

BACKGROUND

The escalating prevalence of adrenal incidentaloma (AI) has been associated with the improvement of radiologic techniques and widespread imaging in aging population. It is currently unclear whether patients with obesity more likely develop AI and the current rise in the prevalence of AI could be at least partly associated with the respective rise in obesity. We compared the prevalence and characteristics of non-functional (NF) and autonomous cortisol secreting (ACS) adrenal incidentalomas (AIs) after the study population was stratified by different body mass indexes (BMI) and age groups.

METHODS

Retrospective cross-sectional study comprising of 432 patients (40.6% male, 59.4% female) with NFAI (N = 290) and ACS (N = 142), of median age 63.4 (54.0-71.6) years and median BMI 28.6 (25.5-31.7) kg/m². The data collection contained 11.132 points including demographic, anthropometric, radiologic, hormonal and metabolic parameters.

RESULTS

We observed 68-87% higher prevalence of AI across different age groups in NFAI and ACS in obese/overweight compared to normal weight subjects. Patients with ACS were older (P = 0.008), with higher basal cortisol (P < 0.001), lower basal DHEAS (P = 0.001), lower suppression DHEAS (P = 0.027) and higher aldosterone (P = 0.039). AIs with ACS were larger than NFAI (P < 0.001). Interestingly, ACS group had lower body mass (P = 0.023) and did not differ in BMI, blood pressure, heart rate, lipid profile, fasting glucose and presence of diabetes mellitus type 2 when compared to NFAI., By contrast to the similarity of metabolic profiles in ACS and NFAI, some components of adverse metabolic traits were rather associated with higher BMI and older age, in particular in NFAI.

CONCLUSION

The prevalence of NFAI and ACS were significantly higher in overweight/obese subgroup across the age distribution. Stratification by age and BMI displayed significant differences in some metabolic traits, in particular in NFAI.

Association of Changes in Metabolic Syndrome Status With the Incidence of Thyroid Nodules: A Prospective Study in Chinese Adults

Although several cross-sectional studies have shown an association of metabolic syndrome (MetS) with nodular thyroid disease, related prospective studies are scarce. This study investigated the association of MetS with thyroid nodule (TN) incidence in Chinese adults, and explored whether the development of or recovery from MetS is associated with changes in the risk of developing TNs. A total of 4,749 Chinese aged 18-65 years were involved in this 6-year prospective study. The association of MetS with TN prevalence was examined. TN-free individuals at baseline (n = 3,133) were further examined. TN incidence rates in groups with different MetS statuses (MetS-free, MetS-developed, MetS-recovery and MetS-chronic) were analyzed. Of all participants, 18.21 and 31.65% had MetS and TNs, respectively. MetS patients had a higher TN prevalence than the non-MetS group (31.08 vs. 19.81% in males, p < 0.01; 59.52 vs. 39.59% in females, p < 0.01). Sex, age and MetS were independent risk factors for TNs. At a median follow up of 5.94 years, the MetS-chronic group (4.37/100 person-years) had a higher risk of TNs (adjusted incidence rate ratio [IRR] = 1.288 [95% CI 1.014-1.636]) compared with the MetS-free group (2.72/100 person-years) in the whole cohort. In males, the MetS-chronic group (3.76/100 person-years) had a higher risk of TNs (adjusted IRR = 1.367 [95% CI 1.017-1.835]) compared with the MetS-free group (2.31/100 person-years). In females, the risk of TNs was significantly higher in the MetS-chronic (6.44/100 person-years) and MetS-developed (6.31/100 person-years) groups compared with the MetS-free group (3.23/100 person-years).

Review of Factors Contributing to Nodular Goiter and Thyroid Carcinoma

There is an increased incidence of thyroid nodules and cancer. In this article, the reasons for this increase are evaluated and discussed. The factors causing increases in the incidence of nodules are the same as those causing increases in thyroid cancer. There are publications from all over the world regarding the rising incidence of thyroid cancer; it is especially associated with papillary cancer. The literature was reviewed and evaluated with regard to this significant phenomenon. Thyroid-stimulating hormone (TSH) is the main mitotic factor. Any agent that elevates TSH will stimulate nodule formation. Therefore, the incidence of thyroid nodules is high in endemic goiter regions due to iodine deficiency. This paper has described many of the factors causing this higher incidence. Of note, metabolic syndrome and insulin resistance are important factors associated with the increased incidence of nodular goiter and papillary thyroid cancer today. However, these data must be confirmed by other studies in the future.

The Prevalence of Single and Multiple Thyroid Nodules and Its Association with Metabolic Diseases in Chinese: A Cross-Sectional Study

PURPOSE

The present study aims to investigate the prevalence of single and multiple thyroid nodules and its association with metabolic diseases in subjects who participated in the heath examination in China.

METHODS

This is a cross-sectional study. The participants who attend the physical examination at the Health Management Center of Southwest Hospital, Army Military Medical University, between January 2014 and December 2018, were included. Thyroid nodules were diagnosed by thyroid ultrasound. Multivariable logistic regression was used to investigate the association between metabolic diseases and nodular thyroid disease.

RESULTS

A total of 9,146 subjects were included in this study; of them, 2,961 were diagnosed with thyroid nodules, with a prevalence of 32.4%. The prevalence in women was significantly higher than that in men (45.2% vs 26.0%; χ ²  = 339.56, P < 0.001), and the prevalence was gradually increased with age (Z = 20.05, P < 0.001), and the prevalence was gradually increased with age (.

CONCLUSIONS

The prevalence of thyroid nodules was relatively high. Age, female gender, and diabetes are positively associated with nodular thyroid disease. High LDL cholesterolemia is more likely to be associated with multiple thyroid sarcoidosis.

Adrenal gland size in obstructive sleep apnea: Morphological assessment of hypothalamic pituitary adrenal axis activity

Objectives

The association of obstructive sleep apnea (OSA) with hypothalamic pituitary adrenal (HPA) axis activation has not been fully understood from results of previous studies using hormonal assessments. We aimed to investigate the relationship between adrenal size, a potential marker reflecting HPA axis activity, and sleep parameters related to OSA.

Methods

We retrospectively reviewed data on 284 consecutive adult patients aged 20 to 80 y who had undergone polysomnography and abdominal computed tomography (CT). OSA was defined as none/mild (apnea-hypopnea index [AHI] <15, n = 75), moderate (AHI 15 to 30, n = 80), and severe OSA (AHI ≥30, n = 129). Widths of adrenal body and limbs were measured by abdominal CT.

Results

Adrenal size was greater in participants with severe OSA than in those with none/mild or moderate OSA (adrenal body width: 6.03 mm, none/mild OSA; 6.09 mm, moderate OSA; 6.78 mm, severe OSA; p <0.001; adrenal limb width: 3.75 mm, none/mild OSA; 3.95 mm, moderate OSA; 4.26 mm, severe OSA, p <0.001). Multivariate regression analysis showed that not the 3% oxygen desaturation index and time of SpO₂ <90% but a higher arousal index was the only determinant factor for increased adrenal limb width (β = 0.27, p <0.001) after adjusting for other variables that could affect adrenal size. Neither the arousal index nor hypoxic parameters were associated with adrenal body width.

Conclusions

Results indicated that adrenal glands may enlarge in response to longstanding sleep fragmentation, suggesting the involvement of OSA in HPA axis augmentation.

Relationship between metabolic syndrome and thyroid nodules and thyroid volume in an adult population

PURPOSE

The effects of metabolic syndrome (MetS) on thyroid nodules (TN) and thyroid volume (TV), especially the related gender and age disparities, are controversial. In this study, we aimed to assess the relationships between MetS and TN and TV in an adult population.

METHODS

This cross-sectional study was performed in an adult population in Tianjin. A total of 2606 subjects were enrolled. TV and TN were measured by thyroid ultrasonography. Blood samples were collected to measure biochemical and metabolic parameters.

RESULTS

The prevalence of TN was significantly higher in the MetS (+) group than in the MetS (-) group (P < 0.0001). MetS was independently associated with increased TN risk (OR: 1.24, 95% CI: 1.01-1.51). When stratified by gender, MetS was associated with higher prevalence of TN in males (OR: 1.38, 95% CI: 1.05-1.81) compared with females (OR: 1.02, 95% CI: 0.75-1.39). However, the interaction effect of gender and MetS on TN was not statistically significant (P for interaction = 0.94). MetS was associated with the greater risks of TN in both the <60-year-old group (OR: 1.32, 95% CI: 1.05-1.68) and the ≥60-year-old group (OR: 1.84, 95% CI: 1.24-2.73), while the OR value was significantly higher in the elderly group (P for interaction = 0.03). Additionally, TV was significantly higher in subjects with TN (β = 1.94, P < 0.0001) and MetS (β = 0.94, P = 0.0037).

CONCLUSIONS

This study suggested positive relationships between MetS and an increased risk of TN and enlarged TV. Elderly people (≥60 years old) with MetS were associated with a higher risk of TN than younger people (<60 years old). The effect of MetS on TN was not significantly affected by gender.

Thyroid Abnormalities in Patients With Extreme Insulin Resistance Syndromes

CONTEXT

Insulin and leptin may increase growth and proliferation of thyroid cells, underlying an association between type 2 diabetes and papillary thyroid cancer (PTC). Patients with extreme insulin resistance due to lipodystrophy or insulin receptor mutations (INSR) are treated with high-dose insulin and recombinant leptin (metreleptin), which may increase the risk of thyroid neoplasia.

OBJECTIVE

The aim of this study was to analyze thyroid structural abnormalities in patients with lipodystrophy and INSR mutations and to assess whether insulin, IGF-1, and metreleptin therapy contribute to the thyroid growth and neoplasia in this population.

DESIGN

Thyroid ultrasound characteristics were analyzed in 81 patients with lipodystrophy and 11 with INSR (5 homozygous; 6 heterozygous). Sixty patients were taking metreleptin.

RESULTS

The prevalence of thyroid nodules in children with extreme insulin resistance (5 of 30, 16.7%) was significantly higher than published prevalence for children (64 of 3202; 2%), with no difference between lipodystrophy and INSR. Body surface area-adjusted thyroid volume was larger in INSR homozygotes vs heterozygotes or lipodystrophy (10.4 ± 5.1, 3.9 ± 1.5, and 6.2 ± 3.4 cm2, respectively. Three patients with lipodystrophy and one INSR heterozygote had PTC. There were no differences in thyroid ultrasound features in patients treated vs not treated with metreleptin.

CONCLUSION

Children with extreme insulin resistance had a high prevalence of thyroid nodules, which were not associated with metreleptin treatment. Patients with homozygous INSR mutation had thyromegaly, which may be a novel phenotypic feature of this disease. Further studies are needed to determine the etiology of thyroid abnormalities in patients with extreme insulin resistance.

Metformin reduces risk of benign nodular goiter in patients with type 2 diabetes mellitus

Background Whether metformin might affect the risk of benign nodular goiter in patients with type 2 diabetes mellitus has not been investigated. Methods Patients with new-onset type 2 diabetes mellitus during 1999-2005 were enrolled from Taiwan's National Health Insurance database. Analyses were conducted in a propensity score matched-pairs of 20,048 ever users and 20,048 never users of metformin. The patients were followed until December 31, 2011, for the incidence of benign nodular goiter. Hazard ratios were estimated by Cox regression incorporated with the inverse probability of treatment weighting using the propensity score. Results Among the never users and ever users of metformin, 392 and 221 cases were diagnosed of benign nodular goiter during follow-up, with incidence of 457.88 and 242.45 per 100,000 person-years, respectively. The overall hazard ratio for ever versus never users was 0.527 (95% confidence interval: 0.447-0.621). When cumulative duration of metformin therapy was divided into tertiles, the hazard ratios for the first (<25.3 months), second (25.3-57.3 months) and third (>57.3 months) tertiles were 0.815 (0.643-1.034), 0.648 (0.517-0.812) and 0.255 (0.187-0.348), respectively. Sensitivity analyses estimating the overall hazard ratios for patients enrolled in each specific year from 1999 to 2005 consistently showed a lower risk of benign nodular goiter among users of metformin. Conclusion Metformin use is associated with a lower risk of benign nodular goiter in patients with type 2 diabetes mellitus.

Diosgenin and Its Fenugreek Based Biological Matrix Affect Insulin Resistance and Anabolic Hormones in a Rat Based Insulin Resistance Model

Fenugreek is known since ancient times as a traditional herbal medicine of its multiple beneficial effects. Fenugreek's most studied and employed effect is its hypoglycemic property, but it can also be useful for the treatment of certain thyroid disorders or for the treatment of anorexia. The regulation of glucose homeostasis is a complex mechanism, dependent on the interaction of different types of hormones and neurotransmitters or other compounds. For the study of how diosgenin and fenugreek seeds modify insulin sensitivity, we used a rat insulin resistance model induced by high-fat diet. Diosgenin in three different doses (1mg/bwkg, 10mg/bwkg, and 50 mg/bwkg, respectively) and fenugreek seed (0.2 g/bwkg) were administered orally for 6 weeks. Insulin sensitivity was determined by hyperinsulinemic euglycemic glucose clamp method. Our research group found that although glucose infusion rate was not significantly modified in either group, the increased insulin sensitivity index and high metabolic clearance rate of insulin found in the 1 mg/kg diosgenin and the fenugreek seed treated group suggested an improved peripheral insulin sensitivity. Results from the 10 mg/kg diosgenin group, however, suggest a marked insulin resistance. Fenugreek seed therapy results on the investigated anabolic hormones support the theory that, besides insulin and gastrointestinal peptides, the hypothalamic-hypopituitary axis regulated hormones synchronized action with IGF-1 also play an important role in the maintaining of normal glucose levels. Both diosgenin and fenugreek seeds are capable of interacting with substrates of the above-mentioned regulatory mechanisms, inducing serious hormonal disorders. Moreover, fenugreek seeds showed the ability to reduce the thyroid hormone levels at the periphery and to modify the T4/T3 ratio. It means that in healthy people this effect could be considered a severe side effect; however, in hypothyroidism this effect represents a possibility of alternative natural therapy.

Prevalence of hypothyroidism in patients with type 2 diabetes mellitus and hypertension in India: a cross-sectional observational study

PURPOSE

To determine the prevalence of hypothyroidism in patients with type 2 diabetes mel-litus (T2DM), hypertension, and both T2DM and hypertension (T2DM + hypertension) in India.

PATIENTS AND METHODS

In this cross-sectional observational study, adult patients with an established or newly diagnosed T2DM, hypertension, and T2DM + hypertension who were visiting their physicians for a routine clinical checkup were enrolled across 29 sites in India. All the patient-related data were extracted from their medical records. The prevalence of hypothyroidism was evaluated by thyroid function test (levels of serum free thyroxine, free triiodothyronine, and thyroid-stimulating hormone [TSH]). The proportion of obese and overweight hypothyroid patients and dose of thyroxine in overt and subclinical hypothyroidism (SCH) cases (as per TSH values) were assessed during the study. The results were summarized by descriptive statistics.

RESULTS

A total of 1,508 patients (T2DM: 504; hypertension: 501; T2DM + hypertension: 503) were enrolled in the study. The prevalence of hypothyroidism in patients with T2DM, hypertension, and T2DM + hypertension was 24.8%, 33.5%, and 28.9%, respectively. The overall prevalence of hypothyroidism in T2DM (n=1,002) and hypertension (n=1,001) was 26.9% and 31.2%, respectively. The proportion of obese against overweight hypothyroid patients was higher in all indications (T2DM: 16.5% vs 3.4%; hypertension: 23.8% vs 5.4%; T2DM + hypertension: 21.5% vs 3.8%). A considerable proportion of patients with SCH was prescribed thyroxine in T2DM (61.5%), hypertension (61%), and T2DM + hypertension (62.5%) cases. The most commonly prescribed dose (mean) of thyroxine was 50 and 25 µg for overt hypothyroidism and SCH cases, respectively, in all cohorts.

CONCLUSION

There is a high (>20%) prevalence of hypothyroidism in patients with T2DM, hypertension, and T2DM + hypertension. Screening for hypothyroidism should be routinely considered for early diagnosis and effective management.