Prevalence of thyroid dysfunctions in a large, unselected population in Duhok city, Iraqi Kurdistan: A cross-sectional study

Objective: To determine the prevalence of thyroid-stimulating hormone (TSH) alterations and different types of thyroid dysfunctions in both sexes with no age limitations from variety of sources in Duhok province. Patients and Methods: In this retrospective cross-sectional study, we screened 25040 suspicious cases of thyroid diseases in a year (2019), retrieving the data from the computer of three clinical laboratories in the Duhok City; following exclusion of 470 cases, 24568 cases were included to categorize the different types of thyroid dysfunctions. Results: The prevalence of TSH alteration was 25.03%, 20.55% of them had a high concentration being statistically higher in females, while only 4.48% was low TSH with equal prevalence among both sexes. Out of 24568 patients, the prevalence of subclinical hypothyroidism was 94.85%, followed by 2.20%, 1.20%, 0.78%, 0.67%, and 0.31% for each of subclinical hyperthyroidism, primary hypothyroidism, central hyperthyroidism, central hypothyroidism, and primary hyperthyroidism respectively. Conclusions: The studied population had high prevalence of high TSH level (20.55%), being more prevalent in female than in male. Our survey revealed that the distribution of thyroid disorders was vary among different age groups with highest prevalence of subclinical hypothyroidism in all age groups (94.85%); Also, we concluded that middle & advanced ages, and females were more susceptible to thyroid disorders.

Thyroid Hormone Changes Related to Growth Hormone Therapy in Growth Hormone Deficient Patients

The alterations in thyroid function during recombinant human growth hormone (rhGH) treatment have been reported by many authors since this therapy became widely available for patients with growth hormone deficiency (GHD). Decrease of thyroxine level is the most frequent observation in patients treated with rhGH. This paper presents literature data describing changes in thyroid function related to rhGH therapy and a current explanation of mechanisms involved in this phenomenon. The effect of GH on the hypothalamic-pituitary-thyroid (HPT) axis is dependent on a multilevel regulation beginning from influence on the central axis, thyroid, and extra-thyroidal deiodinases activity as well as the impact on thyroid hormone receptors on the end. Changes in central and peripheral regulation could overlap during rhGH therapy, resulting in central hypothyroidism or an isolated slight deficiency of thyroxine. The regular monitoring of thyroid function is recommended in patients treated with rhGH and the decision of levothyroxine (L-thyroxine) supplementation should be made in the clinical context, taking into account thyroid hormone levels, as well as the chance for satisfactory growth improvement.

Improvements in Quality of Life and Thyroid Parameters in Hypothyroid Patients on Ethanol-Free Formula of Liquid Levothyroxine Therapy in Comparison to Tablet LT4 Form: An Observational Study

Levothyroxine (LT4) is a standard therapy in hypothyroidism; however, its bioavailability and therapeutic effects might be affected by many factors. Data shows that therapy with liquid LT4 characterized by quicker pharmacokinetics provides better thyroid hormones control than tablet LT4. We addressed the quality of life (QoL) and efficacy of the new ethanol-free formula of liquid LT4 (Tirosint®SOL) treatment in 76 euthyroid patients with primary (PH, n = 46) and central hypothyroidism (CH, n = 30), and compared the results to retrospective data on equivalent doses of tablet L-T4 therapy. After 8 weeks of liquid LT4 therapy, we found a significant improvement in QoL in both PH and CH patients. TSH levels were unaltered in PH patients. Free hormone levels (fT4 and fT3) increased in all the patients, with the exception of fT3 in the CH group. SHBG and low-density lipoprotein (LDL) also improved. Liquid LT4 therapy provided a better thyroid hormone profile and improvement in patients’ QoL than the tablet form, which was possibly due to the more favorable pharmacokinetics profile resulting in better absorption, as suggested by the increased free thyroid hormone levels. In summary, this is the first study addressing the QoL in hypothyroid patients, including primary and central hypothyroidism, treated with liquid LT4 formula in everyday practice.

Baseline MRI findings as predictors of hypopituitarism in patients with non-functioning pituitary adenomas

Hypopituitarism tends to occur in large pituitary adenomas. However, similar tumors could present with strikingly different hormonal deficiencies. In this study, we looked at MRI characteristics in non-functioning pituitary adenomas (NFPA), which could predict secondary adrenal insufficiency (SAI) and central hypothyroidism (CHT). We reviewed the files of patients with NFPA attending our clinic. Tumor size, invasiveness, MR-signal intensity, and gadolinium enhancement in preoperative MRI were recorded along with documented presurgical hypopituitarism profile. Logistic regression was used to predict SAI, CHT or both (SAI/CHT) based on MRI and demographic parameters. Receiver operating characteristic curves were used to determine their diagnostic utility. 121 patients were included. Older age (P=0.021), male sex (P=0.043), stalk deviation (P<0.0001), contrast enhancement (P=0.029) and optic chiasma compression (P=0.012) were associated with SAI/CHT. Adenoma vertical height, largest diameter, and estimated volume were also strongly associated with SAI/CHT (P<0.0001). These associations remained significant in a multivariate analysis. No tumor smaller than 12mm in vertical height, 17mm in largest diameter, or 0.9 cm3 in volume was associated with SAI/CHT. At cutoff >18mm for vertical height, >23 mm for largest diameter, and >3.2 cm3 the sensitivity was around 90-92% for detecting SAI/CHT. Only vertical height was significantly associated with any one or more pituitary hormonal deficit (P=0.001). In conclusion, adenoma size, independent of the measurement used, remains the best predictor of SAI/CHT in NFPA. Dynamic testing to rule out SAI is probably indicated in adenomas larger than 18 mm vertical height, 23 mm largest diameter and 3.2cm3 adenoma volume.

Predictors of Radiation-induced Hypothyroidism in Nasopharyngeal Carcinoma Survivors after Intensity-modulated Radiotherapy

BackgroundThe aim of the study is to identify clinical and dosimetric factors that could predict the risk of hypothyroidism in nasopharyngeal carcinoma (NPC) patients following intensity-modulated radiotherapy (IMRT). MethodsA total of 404 non-metastatic NPC patients were included in our study. All patients were treated with IMRT. The thyroid function were performed for all patients before and after radiation at regular intervals. The time onset for developing hypothyroidism was defined as the time interval between the completion of RT and the first recorded abnormal thyroid hormone test. The cumulative incidence rates of hypothyroidism were estimated using Kaplan-Meier method. Univariate and multivariate Cox regression analyses were performed to detect the most promising factors that were associated with hypothyroidism. ResultsMedian follow up was 60.6 months. The 3-, 5- and 7- year cumulative incidence rate of hypothyroidism was 39.4%, 49.1% and 54.7%, respectively. The median time to primary hypothyroidism and central hypothyroidism were 15.4 months (range: 2.9-83.8 months) and 29.9 months (range: 19.8-93.6 months), respectively. Univariate and multivariate analyses revealed that younger age, female gender and small thyroid volume were the most important factors in predicting the risk of hypothyroidism. Dtmean (mean dose of thyroid), V30-V50 (percentage of thyroid volume receiving a certain dose level) and VS45-VS60 (the absolute volumes of thyroid spared from various dose levels) remained statistically significant in multivariate analyses. Cutoff points of 45 Gy (Dtmean), 80% (Vt40) and 5 cm3 (VS45Gy) were identified to classify patients as high-risk or low-risk group. ConclusionThyroid Vt40 predicted the risk of hypothyroidism after IMRT for NPC patients. We recommended plan optimization objectives to reduce thyroid V40 to 80%.Trial registration: retrospectively registered.

Carbamazepine drug effect simulating biochemical central hypothyroidism in a patient with Bardet-Biedl syndrome

Carbamazepine (CBZ) is a medication used commonly in epilepsy. Decreases in free T4 levels simulating central hypothyroidism have been reported, although the clinical significance is still unclear. We present a 24-year-old man with Bardet-Biedl syndrome (BBS) who was found to have isolated biochemical central hypothyroidism. BBS is a ciliopathy occasionally associated with anterior pituitary dysfunction. While taking CBZ for epilepsy, his TSH was 1.73 mIU/L (reference range: 0.20–4.00 mIU/L) with a low free T4 of 6.6 pmol/L (reference range: 10.0–26.0 pmol/L). Pituitary MRI was normal. Although treated with levothyroxine initially, his apparent biochemical central hypothyroidism was later recognised as secondary to CBZ drug effect. This was confirmed with a normal free T4 of 12.2 pmol/L while he was off CBZ and levothyroxine. Despite the association between CBZ and biochemical central hypothyroidism, nearly all patients remain clinically euthyroid. This effect is reversible and recognition could lead to reductions in unnecessary thyroid replacement therapy if CBZ is discontinued.

Pathophysiological and clinical aspects of interaction between coronavirus disease 2019 and thyroid

In patients who were not previously diagnosed with any thyroid conditions, the scenario of COVID-19 related anomalies of the thyroid may include either: a process of central thyroid-stimulating hormone disturbances via virus‑related hypophysitis; an atypical type of subacute thyroiditis which is connected to the virus spread or to excessive cytokine production including a destructive process with irreversible damage to the gland or low triiodothyronine syndrome (non-thyroidal illness syndrome) which is not specifically related to the COVID‑19 infection, but which is associated with a very severe illness status. This review aimed to investigate thyroid changes resulted from the COVID-19 infection. Ongoing assessment of the effects of the COVID-19 pandemic will reveal more information on coronavirus-induced thyroid conditions. Routine thyroid assays performed in patients with severe infection/acute phase of COVID-19 are encouraged to detect thyrotoxicosis. After recovery, thyroid function should be assessed to identify potential hypothyroidism. There remain unanswered questions related to the predictive value of interleukin-6 in infected patients, especially in cases of cytokine storm, and the necessity of thyroid hormone replacement in subjects with hypophysitis-related central hypothyroidism.

Myxedema coma in COVID-19

SARS-CoV-2 infection is associated with thyroid disorders. It has been reported that myxedema coma (MC) can be complicated with COVID-19. COVID-19-related thyroid disorders consist of a broad spectrum of thyroid dysfunction, from thyrotoxicosis to decompensated hypothyroidism. It is possible that both primary and central thyroid disorders are induced by COVID-19 due to systemic inflammatory and immune responses. We experienced two cases in which patients with COVID-19 developed MC with central hypothyroidism. It is likely that MC affected the severity of COVID-19. It is necessary to consider the existence of MC during SARS-CoV-2 infection. We propose the potential mechanisms.