Risk of developing pneumonia associated with clinically diagnosed hypothyroidism: a nationwide population-based cohort study

Background Hypothyroidism has a detrimental effect on the immune system, which may predispose patients to infection. However, evidence about the risk of developing either community- or hospital-acquired pneumonia in patients with hypothyroidism is scarce. Objective To evaluate the association between hypothyroidism and the risk of developing pneumonia. Methods This was a retrospective population-based cohort study from Taiwan’s National Health Insurance Research Database. After 1:1 propensity score matching, 9749 patients (age ≥20 years) newly diagnosed with hypothyroidism between 2001 and 2014 and 9749 patients without hypothyroidism or other thyroid diseases were included in the hypothyroidism and non-hypothyroidism cohorts, respectively, and followed up until 2015. The development of pneumonia was defined as the primary outcome. Cox proportional hazards regression models were used to calculate the hazard ratios (HRs) of developing pneumonia between hypothyroidism and non-hypothyroidism cohorts after adjusting for age, sex and baseline comorbidities. To evaluate whether thyroxine replacement therapy (TRT) modified the risk for pneumonia, we divided patients with hypothyroidism into subgroups: patients who received TRT and those who did not. Results Hypothyroidism was associated with a higher risk of pneumonia [adjusted HR (aHR) 1.38, 95% confidence interval (CI) 1.29–1.49, P < 0.001]. Patients with hypothyroidism who received TRT had a lower risk of pneumonia than patients who did not (aHR 0.85, 95% CI 0.76–0.93, P = 0.001). Similar results were obtained in the age- and sex-stratified analyses. Conclusions Clinically diagnosed hypothyroidism was independently associated with the risk of pneumonia. In patients with hypothyroidism, TRT was associated with a lower risk of pneumonia.

Hypothyroidism and the Risk of Venous Thromboembolism: A Nationwide Cohort Study

Background Previous studies have shown that hypothyroidism may have an impact on blood coagulation. However, how hypothyroidism and thyroxine replacement therapy (TRT) affect the risk of venous thromboembolism (VTE) remains controversial. This study aimed to examine the associations of hypothyroidism and TRT with VTE risks. Materials and Methods This nationwide population-based cohort study was conducted using Taiwan's National Health Insurance Research Database. We enrolled 10,818 hypothyroid patients (the exposed cohort) and 21,636 non-hypothyroid subjects (the unexposed cohort) between 2001 and 2014 after 1:2 exact matching according to age, sex, and index year. Hypothyroid patients were further divided into two groups depending on whether they received TRT or not. Adjusted hazard ratios (aHRs) for VTE were calculated using Fine and Gray competing risk models. Results The mean follow-up period was 7.5 years. Hypothyroidism was significantly associated with a higher risk of VTE (aHR = 1.83 [95% confidence interval [CI]: 1.44–2.33, p < 0.001]). Among hypothyroid patients, the TRT subgroup had a non-significant trend of lower VTE risk than the non-TRT subgroup (aHR = 0.73 [95% CI: 0.52–1.01, p = 0.058]). The analysis for individual events revealed a significant association between TRT use and a lower risk of pulmonary embolism among hypothyroid patients (aHR = 0.34 [95% CI: 0.13–0.88, p = 0.026]). Conclusion The data suggest that hypothyroidism was significantly associated with an increased risk of VTE. Among hypothyroid patients, a non-significant trend of lower VTE risk in patients treated with TRT was observed. Further prospective studies or clinical trials are necessary to confirm causality.

Lingual and Mediastinal Ectopic Thyroid with No Normal Thyroid Gland – A Very Rare Occurrence

Introduction Ectopic thyroid is a rare congenital condition. Dual ectopic thyroid is rarer still with only 30 cases reported in literature. The most common location is the lingual or sublingual region followed by the hyoid region. Instances of dual ectopic thyroid with one in lingual region and the other in mediastinum are very few. Case Report A case of dual ectopic thyroid is presented with absent normal thyroid in a girl of 14 years who presented with difficulty in swallowing and lump sensation in throat. Ultrasound, MRI scan and Technetium 99m pertechnetate thyroid scan were done. She showed lingual thyroid and thyroid tissue in upper mediastinum and no thyroid tissue in the normal anatomical location. Discussion The discovery of mediastinal ectopic thyroid was incidental. She had subclinical hypothyroidism and was treated with thyroxine replacement therapy.

Thyroid Peroxidase Antibody among Hypothyroid Patients and Clinical and Biochemical Response to L-Thyroxine Replacement Therapy

This study was carried out in the Department of Medicine, Rajshahi Medical College, in 2006-2007 to study the thyroid peroxidase (TPO) antibody level among hypothyroid patients and to find out the effects of L-thyroxine therapy in TPO-antibody titer. After thorough physical examination and relevant investigations, 100 patients of hypothyroidism were enrolled in this study. The selected patients were given L-thyroxine replacement therapy at a dose of 50-150 microgram/d. Before starting L-thyroxine, serum was collected from all patients to estimate anti TPO-antibody level. All patients were followed-up after 12-28 weeks of full dose of L-thyroxine therapy. Patients with high TPO-Abs at baseline, only 17.6% turned into euthyroid (based on composite clinical score), whereas about 42% of the patients who did not have high TPO-Abs became euthyroid suggesting that patients with high TPO Abs may show significantly poor response to treatment compared to the patients without high TPO Abs (p < 0.001). Patients with high TPO-Ab titers also showed a decreased biochemical response (TSH values) compared to the patients without high TPO-Ab positive patients. So, TPO-Ab plays a significant role in causation of the disease and is also associated with poor treatment response with L-thyroxine replacement therapy. TAJ 2018; 31(2): 45-49

Adrenal Steroids in Female Hypothyroid Neonates: Unraveling an Association Between Thyroid Hormones and Adrenal Remodeling

Context The adrenal gland undergoes substantial remodeling during the neonatal period, an essential developmental process that remains incompletely understood. With respect to control over the remodeling process and, specifically, the role of thyroid hormones (THs), no human studies have been published. The effects of both hypo- and hyperthyroidism have only been evaluated in adults, focusing on the mature adrenal. Recent studies have identified expression of the TH receptor β1 in the mouse adrenal X-zone and have demonstrated that TH administration could alter the postnatal adrenal remodeling process. Objective To address whether THs influence adrenal steroid profiles and adrenal remodeling during the neonatal period. Methods We compared the adrenal steroid profile of a naturally occurring prototype, female neonates with severe congenital hypothyroidism (CH) (n = 22, upon diagnosis of CH), with that of euthyroid neonates (n = 20). Results Significantly higher levels of adrenal steroids (17-OH-progesterone, dehydroepiandrosterone sulfate, Δ4-androstenedione, and testosterone) were measured in neonates with severe CH compared with euthyroid neonates and returned to within normal range after euthyroid state had been established on l-thyroxine replacement therapy, whereas cortisol levels did not differ. TSH values in the CH group were positively correlated with circulating adrenal steroids, whereas free T4 levels were negatively correlated with circulating adrenal steroids. Conclusions The hormonal profile of female neonates with severe CH suggests a more active adrenal fetal zone compared with control subjects. These data indirectly associate THs with the adrenal remodeling and maturation process in humans. Based on our results, we suggest that severe hypothyroidism decelerates the involution of the adrenal fetal zone that normally occurs postnatally.

SYSTEM OF REPRODUCTION IN HYPOTHYREOSIS

Hypothyreosis is one of the most common endocrine pathologies closely related with the reproductive system. In female patients with hypofunction of the thyroid gland, various disorders occur in the reproductive system: menstrual cycle deteriorations, miscarriage, infertility. Therefore, the study of thyroid function should be carried out as a screening in women planning pregnancy, as well as in infertile couples in the treatment of the infertility. When hypothyreosis is detected, L-thyroxine replacement therapy is necessary.

Beneficial Effects on Pregnancy Outcomes of Thyroid Hormone Replacement for Subclinical Hypothyroidism

Background. Hypothyroidism and raised thyroid antibody levels have been associated with adverse obstetrical outcomes. Several studies have investigated causal associations, but results have been inconsistent and few studies have reported the effects of thyroxine replacement therapy on pregnancy outcomes in hypothyroid patients.Objective. The primary study objective was to determine the outcome of pregnancies in women diagnosed with overt and subclinical hypothyroidism (SCH) (serum TSH > 2.5 mIU/L) and those with elevated circulating thyroid autoantibody levels in the first trimester of pregnancy and after the institution of appropriate thyroxine replacement therapy to maintain the serum TSH ≤ 2.5 mIU/L.Study Design. This prospective observational study was undertaken between 2013 and 2016. Blood samples were taken from 1025 women at presentation for thyroid stimulating hormone (TSH), anti-thyroglobulin antibodies (TGAb), and thyroid peroxidase antibodies (TPOAb). Those with a TSH > 2.5 mIU/L were treated with thyroxine and managed appropriately to ensure that the TSH was maintained ≤2.5 mIU/L. Outcomes in these patients were compared to those in euthyroid patients. Maternal antenatal complications and perinatal outcomes were recorded.Results. There were a total of 1025 patients of whom 382 (37.5%) were nulliparous. 10.1% had a TSH level > 2.5 mIU/L and 18.2% had at least one raised thyroid antibody level. No differences in adverse outcomes of pregnancy were evident in women treated for SCH or overt hypothyroidism compared to the euthyroid group. There was also no association between raised thyroid antibodies and adverse pregnancy outcomes in either group.Conclusion. There were no adverse outcomes of pregnancy found in pregnant women who had been diagnosed and treated with thyroxine for SCH at the time of presentation when compared to euthyroid patients. There was also no relationship with thyroid antibodies and adverse pregnancy outcomes in the two groups. It is not possible to unequivocally advocate for thyroxine replacement in pregnant women with subclinical and overt hypothyroidism until large scale randomized controlled trials are performed.