Background and Objectives: Electrodiagnostic changes typical of peripheral polyneuropathy have been reported in patients with over hypothyroidism. There are controversial reports regarding the effects of subclinical hypothyroidism on peripheral nervous system function. The aim of the present study is to investigate the possible effects of subclinical hypothyroidism of peripheral nervous system function by electrodiagnostic studies.Material and Methods: A total of 28 patients (56 extremities) with subclinical hypothyroidism (defined as high serum TSH in the presence of normal free thyroxin by appropriate methods) including 25 adult females and 3 males (mean age of 46.07 ± 6.87y) and 30 normal subjects as control group (60 extremities). 27 females and 3 males (mean age 45±8.7y) had normal thyroid function tests enrolled in the study. Exclusion criteria were presence of diabetes mellitus, neuromuscular disorder, pregnancy, other disorders or drugs affecting neuromuscular function in all patients and control group. Electrodiagnostic studies including motor nerve conduction velocity (motor NCV), motor distal latency, CMAP Amplitude performed from tibial, median, peroneal and ulnar nerves bilaterally. Sensory function tests including sensory nerve conduction velocity, SNAP amplitude and sensory distal latency from median, ulnar and sural nerves bilaterally were studied by standard methods. Minimal f-response was studied from tibial, median and ulnar nerves bilaterally.Results: Mean of sensory NCV, SNAP amplitude and sensory distal latency from median, ulnar and sural nerves and motor NCV, motor distal latency and CMAP amplitude from median, ulnar, personeal and tibial nerves and mean of minimal F-response of tibial, median and ulnar nerves were not significantly different in patients and control group.Conclusion: The result of this study shows that there is no functional impairment in peripheral nerves in subclinical hypothyroidism at the time of diagnosis.

Introduction: Obestatin is a gastrointestinal-peptide hormone which influences glucose and lipid metabolism, body weight and energy homeostasis. Very little is known about the association between gut peptides and thyroid diseases. The aim of the present study was to investigate the association between serum concentrations of obestatin and thyroid function in subclinical hypothyroid and hyperthyroid subjects.Materials and Methods: This study was performed on 35 hypothyroid, 35 hyperthyroid and 35 euthyroid subjects (controls) who referred to the Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences. In all participants, serum levels of obestatin, TSH, FT3, FT4, insulin, glucose as well as BMI were assessed. Serum obestatin, FT3, FT4 and TSH were measured by ELISA, Electrochemiluminescence immunoassay (ECLIA) and Immunoradiometric assay (IRMA), respectively. Data were analyzed by T-test, One-Way ANOVA and Pearson correlation using SPSS 16.Results: Serum concentrations of obestatin in both hypothyroidism and hyperthyroidism (0.04±0.01 and 0.05±0.02 ng/ml respectively) were significantly lower than in the control group (0.09±0.01 ng/ml), (P-value<0.001). No significant correlations were observed between serum levels of obestatin and FT3, FT4, and TSH.Conclusion: Our results indicated obestatin concentrations were significantly associated with thyroid function.

Background and Objectives: Subclinical hypothyroidism affects 6-17% of general population. Given that mild increase in TSH level leads to dyslipidemia, it can be associated with cardiovascular disease.The present study aimed to investigate the effect of early levothyroxine treatment on blood lipid profile in subclinical hypothyroid patients (with serum TSH level less than 10mIU/l and normal lipid level.Methods: In this clinical trial, 82 subclinical hypothyroid patients with normal FT4 (free T4), TSH of 5.2-10mIU/L and normal lipid level, were investigated. The patients were randomly divided into experimental and control groups. The experimental group received levothyroxine for 2 months and then both groups were evaluated. Data were analyzed using Kolmogorov-Smirnov and t tests. The level of significance was considered less than 0.05.Results: The mean age in experimental and control groups were 39.68±9.25 and 37.63±9.99 years, respectively. FT4 level significantly increased, and HDL, LDL, triglyceride, and cholesterol levels significantly decreased in the experimental group after two months of treatment with levothyroxine.Conclusion: The results of this study revealed that levothyroxine treatment in subclinical hypothyroid patients significantly decreases serum levels of HDL, LDL, triglyceride, and cholesterol.

Introduction: Thyroid disorders and gestational diabetes are the most common endocrine disorders during pregnancy. Given the important role of thyroid hormones in glucose metabolism and homeostasis, it seems that thyroid disorders can have significant effects on glucose metabolism and insulin secretion and may contribute to gestational diabetes. This review aimed to investigate the association between gestational diabetes and subclinical hypothyroidism in pregnancy. Results: The results of previous studies on the relationship between hypothyroidism and gestational diabetes are inconsistent. Evidence suggests an association between thyroid autoimmune disorders and gestational diabetes. Conclusions: Considering the differences in race, geographic region, genetic factors, environmental factors, diagnostic criteria for gestational diabetes, and the cut-off thresholds for thyroid function during pregnancy in different studies, it is not possible to confirm the association between gestational diabetes and hypothyroidism in pregnancy.

Introduction: Thyroid dysfunction can impair fat and glucose metabolism, blood pressure, and body weight. On the other hand, metabolic syndrome (MetS) can be associated with an increased risk of hypothyroidism. Due to the high prevalence of both disorders and the possibility of synergistic metabolic detrimental consequences in combination, this review study aimed to investigate the reciprocal association between thyroid function and MetS. Materials and Methods: Articles in PubMed and Web of Science written in English were searched from 1991 to 2021 using search terms hypothyroidism, hyperthyroidism, thyroid hormones, thyroxine, thyroid-stimulating hormone, and metabolic syndrome in titles and abstracts. Results: Hypothyroidism and even changes in thyroid hormones within the normal range are associated with disorders of various metabolic risk factors,however, the risk of developing MetS in people with both euthyroidism and subclinical hypothyroidism remains a controversial issue. Hyperthyroidism may be associated only with insulin resistance and impaired blood sugar levels (dysglycemia). Although the effect of various metabolic disorders such as obesity and diabetes on thyroid function has been observed, the results are contradictory regarding the prevalence and incidence of thyroid dysfunction in patients with MetS and healthy individuals. Conclusion: The association between MetS, thyroid function, and thyroid hormones is reciprocal and complex and may be affected by age, gender, insulin resistance, smoking, iodine intake, and inflammatory markers.

Introduction: Subclinical hypothyroidism is the compensatory stage before overt hypothyroidism. In overt hypothyroidism, risk of ischemic heart disease increases due to elevation of lipoprotein (a) as atherogenic agent, but evidence for subclinical hypothyroidism is one of the controversial issues in researches. According to the atherogenic lipoprotein (a) and other serum lipids, this study is conducted to compare the serum lipoprotein (a) and other serum lipids in patients with subclinical hypothyroidism and euthyroidism.Materials and Methods: In this descriptive-analytic study 90 persons (60 with subclinical hypothyroidism and 30 euthyroid state) are participated and these referred to Imam Reza and Taleghani Hospitals which are located in Kermanshah. The sampling method is selected with available sampling methods. After differentiating data by age, sex and underlying disease (liver, kidney, drugs), then they were subjected to determination lipoprotein (a) and other serum lipids profile tests.Findings: In both cases and controls, 16.7% were men and 83.3% were women. Based on results, there is no significant difference between serum lipoprotein (a), triglycerides, cholesterol, HDL and LDL in both statistical groups (P>0.05). Also there is no association between lipoprotein (a) and other serum lipids (P>0.05).Conclusion: Serum levels of lipoprotein (a) and other serum lipids in young patients with normal weight with subclinical hypothyroidism is not increase, thus it can be concluded early treatment is not necessary for them.

Subclinical hypothyroidism is one of the common thyroid disorders in women with polycystic ovary syndrome, which can lead to adverse outcomes. This review explored the effects of subclinical hypothyroidism on the clinical and biochemical features and complications of polycystic ovary syndrome. In this review, the keywords of hypothyroidism, subclinical hypothyroidism, polycystic ovary syndrome, metabolic syndrome, and diabetes were searched in the PubMed, Web of Science, Google Scholar, Scientific Information Database, and Magiran database to gather relevant publications up until May 2023. According to available evidence, adipose tissue disorders, inflammation, glucose absorption and production disorders, and insulin secretion disorders may lead to insulin resistance. Insulin resistance, in turn, predisposes to the occurrence of cardiometabolic and fertility disorders. There is no evidence supporting the exacerbation of clinical symptoms, such as hirsutism, menstrual disorders, and biochemical manifestations, but several pieces of evidence have noted that the probability of lipid and glycemic disorders in individuals with polycystic ovary syndrome may increase in the presence of subclinical hypothyroidism. Also, some studies have pointed out a high risk of fertility complications when polycystic ovary syndrome coincides with subclinical hypothyroidism. When managing the symptoms and complications of polycystic ovary syndrome, more attention should be paid to the potential adverse effects of concurrent subclinical hypothyroidism and related metabolic complications.

Background & Aims: The rate of depression, anxiety, and stress increased in people with subclinical hypothyroidism. It seems that the use of non-pharmaceutical methods such as exercise has a beneficial effect on depression, anxiety, and stress. Therefore, the aim of this study was to investigate the effect of Aerobics exercise on depression, anxiety, and stress in women with subclinical hypothyroidism. Materials & Methods: In this semi-experimental study, Forty-one women with subclinical hypothyroidism were selected through convenience sampling and randomly divided into experimental (n=23) and control groups (n= 18). The experimental group participated in an Aerobics exercise program for three sessions (60 min) per week for eight weeks. The control group did not participate in any exercise training regularly. The data-gathering tool was the DASS-21 questionnaire. Independent and paired samples t-test were used in the significance level 0. 05 to analyze the data. Results: The results of paired samples t-test in the experimental group showed that depression (P=0. 002), anxiety (P= 0. 006) and stress (P= 0. 004) significantly decreased. But the results of paired samples t-test in control group showed that depression (P= 0. 613), anxiety (P= 0. 818) and stress (P=0. 862) did not change significantly. Independent samples t-test showed that aerobics exercise led to significant decreases in depression (P= 0. 037), anxiety (P= 0. 032) and stress (P= 0. 005) in experimental group compared to control group. Conclusion: Based on the findings of this study, it can be concluded that eight weeks of Aerobics exercise can effectively improve depression, anxiety, and stress in women with subclinical hypothyroidism.

Introduction: Type 2 diabetes mellitus (T2DM) and thyroid disorders are common endocrine disorders. It seems that T2DM and thyroid gland dysfunctions are interlinked and influence each other. This study aimed to assess the prevalence of overt hypothyroidism (OH) and subclinical hypothyroidism (SCH) in type 2 diabetic patients admitted to Imam and Golestan Hospitals, Ahvaz, Iran. Materials and Methods: This retrospective study was performed by studying the records of type 2 diabetic patients admitted to Imam Khomeini and Golestan Hospitals, Ahvaz, in 2020-2021. A total of 420 T2DM patients were evaluated using thyroid function tests, including thyroid-stimulating hormone (TSH). OH was considered at TSH levels of ≥,10 mIU/mL and T4 below normal range, and SCH was considered at TSH levels of <5 mIU / mL and normal T4. Results: Of the patients, 34 (8. 1%) had OH, and 61 (14. 5%) had SCH. OH and SCH were more common in females than in males (P<0. 0001). The frequency of OH and SCH was not significantly different based on age groups, weight groups, type of diabetes treatment, duration of diabetes, serum vitamin D level, hypertension, and dyslipidemia. Conclusion: This study showed a high prevalence of OH and SCH in patients, particularly women, with T2DM. Therefore, patients, predominantly females, with T2DM should be routinely screened for hypothyroidism.