Consequences of dysthyroidism on the digestive tract and viscera

Abstract

Thyroid hormones define basal metabolism throughout the body, particularly in the intestine and viscera. Gastrointestinal manifestations of dysthyroidism are numerous and involve all portions of the tract. Thyroid hormone action on motility has been widely studied, but more complex pathophysiologic mechanisms have been indicated by some studies although these are not fully understood. Both thyroid hormone excess and deficiency can have similar digestive manifestations, such as diarrhea, although the mechanism is different in each situation. The liver is the most affected organ in both hypo-and hyperthyroidism. Specific digestive diseases may be associated with autoimmune thyroid processes, such as Hashimoto's thyroiditis and Grave's disease. Among them, celiac sprue and primary biliary cirrhosis are the most frequent although a clear common mechanism has never been proven. Overall, thyroidrelated digestive manifestations were described decades ago but studies are still needed in order to confirm old concepts or elucidate undiscovered mechanisms. All practitioners must be aware of digestive symptoms due to dysthyroidism in order to avoid misdiagnosis of rare but potentially lethal situations.

Autopercepção da deglutição em pacientes com doença tireoidiana benigna não cirúrgica

“…Swallowing dysfunctions are the result of compressive effects or the consequence of surgical interventions (2,3) , with gastrointestinal tract dysmotility leading the complaint reports (4)(5)(6) . Changes in the oropharyngeal transit differ according to the type of thyroid disease and seem to be more concentrated in the laryngopharyngeal region (4)(5)(6)(7)(8)(9)(10)(11)(12) .…”

“…Swallowing dysfunctions are the result of compressive effects or the consequence of surgical interventions (2,3) , with gastrointestinal tract dysmotility leading the complaint reports (4)(5)(6) . Changes in the oropharyngeal transit differ according to the type of thyroid disease and seem to be more concentrated in the laryngopharyngeal region (4)(5)(6)(7)(8)(9)(10)(11)(12) . In hypothyroidism, discomfort is perceived in the cervical region, manifested as dry throat, dyspnea, globus pharyngeus, pain, itching, and burning (5,8) , which are symptoms related to myxedema that compromise laryngeal mobility and the proper functioning of pharyngoesophageal transit (4,6) .…”

“…Changes in the oropharyngeal transit differ according to the type of thyroid disease and seem to be more concentrated in the laryngopharyngeal region (4)(5)(6)(7)(8)(9)(10)(11)(12) . In hypothyroidism, discomfort is perceived in the cervical region, manifested as dry throat, dyspnea, globus pharyngeus, pain, itching, and burning (5,8) , which are symptoms related to myxedema that compromise laryngeal mobility and the proper functioning of pharyngoesophageal transit (4,6) . In patients with thyroid nodules, the symptoms are associated with the degree of compression, and there may be surgical indication even for benign cases (9)(10)(11) .…”

“…In hyperthyroidism, reports indicate specific cases of dysphagia associated with thyrotoxic myopathy, which is a more unusual condition (12) . In spite of these characteristics, these symptoms are often underestimated, undiagnosed, or diagnosed late in this population (4) , which may result in worsening of the overall health and quality of life of patients. Exploring the self-perception of individuals with thyroid disease with respect to their functional condition is an attitude recommended in the literature (13) .…”

Ultrastructural liver changes in the experimental thyrotoxicosis

“…The liver, consequently, plays an important role in the metabolism of thyroid hormones: it is involved in de-iodisation of thyroid hormones with the formation of their active and inactivated forms [2,3,4], in the conversion of organic iodine into iodide; a number of plasma proteins that bind the lipophilic thyroid hormones are synthesised in the liver [1]. Abnormal liver function is observed in 15-76% of patients with pathology of the thyroid gland, according to different authors [1,5,6].…”