Transient Hyperthyroidism following the ingestion of complementary medications containing kelp seaweed

Abstract

Rationale:The prevalence of obesity has increased over the past few years, becoming a public health problem. Generally, the primary therapeutic remedies are diet, physical exercise, medication, and bariatric surgery. However, an increased number of obese and overweight people are using complementary and herbal slimming supplements.Patient concerns:A 70-years-old Caucasian woman presented to the outpatient clinic with tachycardia (>100 bpm), insomnia, anxiety, and recent weight loss (6 kilos in 3 months). She had no previous thyroid disease, but she presented transient hyperthyroidism at 3 months after ingestion of tablets containing kelp seaweeds.Diagnoses:Hypertensive and obese patient, without previous thyroid disease, presented with transient hyperthyroidism at 3 months following ingestion of tablets containing kelp seaweed.Interventions:The kelp-containing tablets were discontinued, and antithyroid therapy with Methimazole was initiated as follows: Methimazole at 15 mg/day for 1 month, at 10 mg/day in the second month, and 5 mg/day for the third month.Outcomes:After 3 months of antithyroid therapy and without the consumption of kelp - containing tablets, normal thyroid function was regained. Further analysis revealed normal thyroid function, so the hyperthyroidism reversed completely.Lessons:Adults who consume complementary medication based on kelp seaweed should be informed of the risk of developing thyroid dysfunction also in the absence of any pre-existing thyroid disease. Due to the high iodine content, supplements containing kelp should be taken with the supervision of a physician and with monitoring of thyroid function.

Iodine Status and Thyroid Function in a Group of Seaweed Consumers in Norway

“…Further studies are required to examine thyroid function in macroalgae consumers with an excessive iodine intake. Previously, several case studies have reported iodine-induced thyroid dysfunction in adults consuming seaweed [ 42 , 43 , 44 , 45 ]. Thyroid dysfunction has also been seen in new-born babies after excessive maternal iodine intake from macroalgae [ 46 , 47 ].…”

Povidone-iodine-induced transient triiodothyronine thyrotoxicosis in a Japanese patient with prolonged habitual gargling: A case report and literature review

“…We reviewed the findings of thyroid scintigraphy and thyroid color Doppler ultrasonography in previously reported cases of iodine-induced hyperthyroidism in patients without a history of thyroid disease (Table 1). [3,7,[10][11][12][13][14][15][16][17][18] Although many reports describe decreased radioiodine intake, [10][11][12]16] radioiodine uptake varies widely in cases of amiodarone-induced hyperthyroidism type 1. [6] In iodine-induced hyperthyroidism, color Doppler thyroid ultrasonography generally shows increased blood flow [6,14] ; however, cases without increased blood flow also exist.…”

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“…Graves-Basedow disease is an autoimmune disease triggered by certain viral or bacterial infections (e.g., Yersinia enterocolitica), psychological stress, smoking, estrogen and postpartum period, excessive administration of iodine (especially in iodine deficient areas) or of drugs certain drugs such as Amiodarone (Gherbon et al, 2019). The manifestations of the disease include thyrotoxicosis, ophthalmopathy, goiter, dermopathy (pretibial myxedema).…”