You may also like to read an article I wrote on detoxification (here) and thyroid function, (here). In fact you may also be interested in this article (here) discussing the relationship between the sex hormones, in particular oestrogen and gut health.
The point I want to get across?
Our bodily systems are connected and imbalances in one can contribute to imbalances in another. We have to take a functional/holistic/comprehensive (call it what you will) approach to health and wellbeing.
Thyroid disorders commonly impact on the gastrointestinal system and may even present with gastrointestinal symptoms in isolation…….Similarly, gastrointestinal diseases can impact on thyroid function tests, and an awareness of the concept and management of non-thyroidal illness is necessary to avoid giving unnecessary thyroid therapies that could potentially exacerbate the underlying gastrointestinal disease.
Dual thyroid and gastrointestinal pathologies are also common, with presentations occurring concurrently or sequentially, the latter after a variable time lag that can even extend over decades.
Such an association aetiologically relates to the autoimmune background of many thyroid disorders (e.g. Graves’ disease and Hashimoto’s thyroiditis) and gastrointestinal disorders (e.g. coeliac disease and inflammatory bowel disease); such autoimmune conditions can sometimes occur in the context of autoimmune polyglandular syndrome.
Modest weight gain, in spite of reduced appetite, can occur in hypothyroidism due to reduced metabolism and accumulation of fluid rich in glycosaminoglycans (myxoedema). Hypothyroidism can be associated with anaemia. Hypothyroidism-induced menorrhagia in women can lead to microcytic, iron deficiency anaemia.
Upper gastrointestinal dysfunction
Oropharyngeal dysphagia has been described in people with hypothyroidism, as well as oesophagitis and hiatus hernia with more distal oesophageal involvement. Hashimoto’s thyroiditis is associated with a goitre, which can also cause dysphagia. One study reported mean oesophageal transit and gastric emptying timeswere significantly prolonged in people with hypothyroidism compared to healthy controls; all hypothyroid participants reported minor dyspeptic symptoms. This study did not identify any significant link between reduced gastric emptying and gastric mucosal pathology. The authors did advocate checking thyroid function tests in patients presenting with dyspepsia. Such delayed gastric emptying has been shown to resolve with treatment of the underlying hypothyroidism.
Constipation is the most commonly seen intestinal effect of hypothyroidism. Small intestinal bacterial overgrowth has also been described. In one study, when patients with a previous history of overt hypothyroidism (butwhowere rendered euthyroidwith levothyroxine therapy) were tested with a hydrogen glucose breath test, 54% were found to be positive versus 5% in controls. Abdominal discomfort, bloating, and flatulence were significantly associated with the presence of bacterial overgrowth andwere significantly improved following antibiotic therapy. Reduced GI motility may be implicated as it can reduce the ability of the small bowel to prevent stasis and overgrowth of luminal bacteria. It would therefore seem reasonable to test for small intestinal bacterial overgrowth in patients who have persisting gastrointestinal symptomatology despite resolution of their hypothyroidism. Hypothyroidism should be considered in the differential diagnosis of irritable bowel syndrome, gastrointestinal bleeding, megacolon, ileus, and colonic pseudo-obstruction.
Hypothyroidism commonly reduces hepatic metabolism and induces hepatic dysfunction. Symptoms such as fatigue, muscle cramps, andmyalgias can be manifestations of both conditions and can cause diagnostic uncertainty. Deranged LFTs are seen in about half of patients with hypothyroidism (albeit often mildly deranged) despite normal hepatic histology, and thyroid function tests should be considered in all patients with deranged LFTs. Microscopically, reduced hepatic oxygen consumption and gluconeogenesis are observed. Hypothyroidism causes reduced gallbladder motility, reduced bilirubin excretion, and hypercholesterolaemia, and hence increases the risk of gallstones. Hypothyroidism is also twice as common in nonalcoholic fatty liver disease (NAFLD) compared to other causes of chronic liver disease (15% versus 7%, respectively).
Thyroid autoimmunity and the gut
Autoimmune thyroid disease (AITD) can be associated with autoimmune disorders of the digestive system such as pernicious anaemia, coeliac disease, inflammatory bowel disease, and primary biliary cirrhosis.
When suffering with digestive, thyroid or liver conditions we need to investigate and likely support other organs or systems, as part of a comprehensive programme. This is crucial to the success of the interventions and to the long term health and wellbeing of the patient.
This article inudes large chunks of the original published paper by Kyriacou et al. (2015) entitled: ‘Thyroid disorders and gastrointestinal and liver dysfunction: A state of the art review’.