Myxedema coma secondary to levothyroxine malabsorption in a patient previously submitted to bariatric surgery

SUMMARY Treating hypothyroidism can be challenging in patients with malabsorption, as they require a higher daily dose of oral levothyroxine (L-T4). Oral L-T4 absorption occurs mainly in the jejunum and the ileum and is affected by gastric acidity. As a result, absorption can be impaired by bariatric surgery. This paper presents a case of myxedema in a young man who had previously undergone biliopancreatic diversion. He was referred to the Emergency Department with deteriorated mental state, hypotension, bradycardia and hypothermia. Laboratory tests revealed severe hypothyroidism and hypokalaemia. The clinical and biochemical profile of the patient suggested myxedema coma. The tablet-based L-T4 therapy was replaced with intravenous (iv) L-T4, oral liquid L-T4 and oral liothyronine (L-T3) and inotropic agents and supportive care were also administered, resulting in a gradual improvement in clinical condition. The patient reported taking L-T4 tablets as prescribed before hospitalization. In patients with malabsorption, impaired L-T4 absorption may lead to severe forms of hypothyroidism. This case outlines the need for more frequent monitoring of serum Thyroid Stimulating Hormone in patients submitted to bariatric surgery and suggests the benefit of using liquid L-T4 in the place of tablets in cases of malabsorption.

Thyroid disease and autoimmunity in obese patients: a narrative review.

INTRODUCTION: The high prevalence of obesity and thyroid diseases worldwide justifies di per se their simultaneous coexistence. In recent decades, there has been a parallel and significant rise in obesity and thyroid diseases in industrialised countries, although the underlying mechanisms are complex and not well known. MATERIAL AND METHODS: The authors accomplished a comprehensive literature search of original articles concerning obesity and thyroid status. Original papers exploring the association between these two morbidities in children and adults were included. RESULTS: A total of 79 articles were included in the present analysis. A total of 12% of obese children (mean age 10.9 ± 1.4 years) showed a thyroid disease, and they were younger than healthy obese children (10.9 ± 1.2 vs. 11.0 ± 0.4 years, p < 0.001). Isolated hyperthyrotropinaemia was the most frequent finding in children (10.1%). Autoimmune thyroid disease was more frequent in puberal age. Thyroid antibodies and subclinical hypothyroidism were more frequent in obese that in non-obese patients (7% vs. 3%, p < 0.001; 10% vs. 6%, p < 0.001). Among obese adults, 62.2% displayed a thyroid disease; those affected were younger (35.3 ± 6.8 vs. 41.0 ± 1.9 years, p < 0.001), heavier [body mass index (BMI): 39.4 ± 6.3 vs. 36.1 ± 2.3 kg/m², p < 0.001], and more frequently female (13% vs. 8%, p < 0.001). The most frequent disease was overt hypothyroidism (29.9%). BMI appears to be correlated with TSH levels in obese adults. Overt hypothyroidism was significantly more frequent in obese patients (7% vs. 3%, p < 0.005), but no difference was found in thyroid antibodies (15% vs. 14%, p = 0.178). CONCLUSIONS: An undeniable relationship between obesity and thyroid impairments exists. Isolated hyperthyrotropinaemia is frequently seen in obese children, often followed by spontaneous resolution. Subclinical hypothyroidism should never be treated in children or adults with the aim of reducing body weight.

Autoimmune polyglandular syndrome type 4: experience from a single reference center.

Purpose: To characterize patients with APS type 4 among those affected by APS diagnosed and monitored at our local Reference Center for Autoimmune Polyglandular Syndromes. Methods: Monocentric observational retrospective study enrolling patients affected by APS diagnosed and monitored in a Reference Center. Clinical records were retrieved and analyzed. Results: 111 subjects (51 males) were affected by APS type 4, mean age at the onset was 23.1 ± 15.1 years. In 15 patients the diagnosis of APS was performed during the first clinical evaluation, in the other 96 after a latency of 11 years (range 1-46). The most frequent diseases were type I diabetes mellitus and celiac disease, equally distributed among sexes. Conclusions: The prevalence of APS type 4 is 9:100,000 people. Type I diabetes mellitus was the leading indicator of APS type 4 in 78% subjects and in 9% permitted the diagnosis occurring as second manifestation of the syndrome. Our data, showing that 50% of patients developed APS type 4 within the first ten years, don't suggest any particular follow-up time and, more importantly, don't specify any particular disease. It is important to emphasize that 5% of women developed premature ovarian failure.

Interference or Noninterference Between Soy and Levothyroxine: That Is the Question. A Narrative Review of Literature.

OBJECTIVE: To evaluate the effect of soy intake on levothyroxine (L-T4) absorption among different L-T4 formulations. METHODS: A PubMed/MEDLINE, Web of Science, and Scopus research was performed. Case reports, case series, and original studies written in English and published online up to November 30, 2022, were selected and reviewed. The final reference list was defined based on the relevance of each study to the scope of this review. RESULTS: Few data, mainly case reports, seemed to suggest a possible interference of soy products on L-T4 tablets absorption. However, the only prospective randomized cross-over study showed no differences in L-T4 absorption when L-T4 and soy isoflavones were assumed concomitantly. The very little data available on liquid L-T4 formulations did not allow for any conclusions to be made, even if a double-blind placebo-controlled trial showed no impaired L-T4 absorption. CONCLUSION: The inference of soy products on L-T4 absorption, if present, seems to have little clinical impact. Considering this fact, the Hamlet-like question whether soy milk interferes with L-T4 absorption remains unanswered.

Liquid levothyroxine formulations in patients taking drugs interfering with L-T4 absorption.

Purpose: To describe the current knowledge on thyroid hormonal profile in patients on liquid L-T4 therapy and drugs known to interfere with L-T4 absorption. Methods: A PubMed/MEDLINE, Web of Science, and Scopus research was performed. Case reports, case series, original studies and reviews written in English and published online up to 31 August 2022 were selected and reviewed. The final reference list was defined based on the relevance of each paper to the scope of this review. Results: The available data showed that novel levothyroxine formulations circumvent gastric pH impairment due to multiple interfering drugs such as proton pump inhibitors, calcium or iron supplements, sevelamer, aluminum/magnesium hydroxide and sodium alginate. Conclusion: New formulations can be taken simultaneously with drugs interfering with L-T4 absorption, in particular liquid formulations. Softgel capsules need more studies to support these data.

Endocrine system after 2 years of COVID-19 vaccines: A narrative review of the literature.

Purpose: The purpose of this study was to describe the current knowledge on the potential endocrine adverse effects post-COVID-19 vaccines. Methods: A PubMed/MEDLINE, Web of Science, and Scopus research was performed. Case reports, case series, original studies, and reviews written in English and published online up to 31 July 2022 were selected and reviewed. The final reference list was defined based on the relevance of each paper to the scope of this review. Results: The available data showed that endocrine side effects are generally rare and with favorable outcome, being thyroid disorders the most common. Conversely, data on type 1 diabetes mellitus are rare; adrenal and pituitary events are even anecdotal. Finally, the available clinical studies suggest no impact on female reproductive system and on male and couple fertility. Conclusion: Overall, these data show that, after 2 years of COVID-19 vaccines, the endocrine system is not heavily threatened.