Orocaecal transit time in health and in thyroid disease

Thyroid disorders and gastrointestinal dysmotility: an old association

Gastrointestinal motility symptoms may be closely related to thyroid diseases. Sometimes, such symptoms are the only thyroid disease-related clue although the degree of the symptoms may vary. The exact mechanism of action of thyroid hormones on gastrointestinal motility is not completely understood, however, a clue lies in the fact that muscle cell receptors can be directly acted upon by thyroxines. Both hypo- and hyperthyroidism can cause impairment of gastrointestinal motility, modifying structure and function of pharynx and esophagus, and regulating esophageal peristalsis through neuro-humoral interaction. In hyperthyroid patients, alterations of postprandial and basic electric rhythms have been observed at gastro-duodenal level, often resulting in slower gastric emptying. Gastric emptying may also be delayed in hypothyroidism, but an unrelated gastric mucosa-affecting chronic modification may also cause such pattern. Hyperthyroidism commonly show malabsorption and diarrhoea, while hypothyroidism frequently show constipation. In summary, it can be stated that symptoms of gastrointestinal motility dysfunction can be related to thyroid diseases, affecting any of the gastrointestinal segment. Clinically, the typical thyroid disease manifestations may be missing, borderline, or concealed because of intercurrent sicknesses. Motility-linked gastrointestinal problems may easily conceal a misdetected, underlying dysthyroidism that should be carefully analyzed. Here, we aim to elaborate on the associations between thyroid disorders and GI dysmotility and the common clinical manifestations associated with GI dysmotility.

European guideline on indications, performance, and clinical impact of hydrogen and methane breath tests in adult and pediatric patients: European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Neurogastroenterology and Motility, and European Society for Paediatric Gastroenterology Hepatology and Nutrition consensus

INTRODUCTION

Measurement of breath hydrogen (H2 ) and methane (CH4 ) excretion after ingestion of test-carbohydrates is used for different diagnostic purposes. There is a lack of standardization among centers performing these tests and this, together with recent technical developments and evidence from clinical studies, highlight the need for a European guideline.

METHODS

This consensus-based clinical practice guideline defines the clinical indications, performance, and interpretation of H2 -CH4 -breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 44 experts from 18 European countries. Eighty eight statements and recommendations were drafted based on a review of the literature. Consensus (≥80% agreement) was reached for 82. Quality of evidence was evaluated using validated criteria.

RESULTS

The guideline incorporates new insights into the role of symptom assessment to diagnose carbohydrate (e.g., lactose) intolerances and recommends that breath tests for carbohydrate malabsorption require additional validated concurrent symptom evaluation to establish carbohydrate intolerance. Regarding the use of breath tests for the evaluation of oro-cecal transit time and suspected small bowel bacterial overgrowth, this guideline highlights confounding factors associated with the interpretation of H2 -CH4 -breath tests in these indications and recommends approaches to mitigate these issues.

CONCLUSION

This clinical practice guideline should facilitate pan-European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, it identifies areas of future research needs to clarify diagnostic and therapeutic approaches.

Thyroid hormone activated upper gastrointestinal motility without mediating gastrointestinal hormones in conscious dogs

This study was conducted to clarify the relationship between thyroid function and gastrointestinal motility. We established an experimental configuration in which the feedback of thyroid function was completely removed using conscious dogs. With hypothyroidism, time of phase I of interdigestive migrating contractions (IMC) was longer, time of phase II and phase III was significantly shortened, and both the continuous time of strong tetanic contraction at antrum and 10-h frequency of phase III counted from the first IMC after meal significantly decreased. Whereas, hyperthyroidism caused the opposite events to those with hypothyroidism. Furthermore, We found giant migrating contractions (GMC) occurred from the upper gastrointestinal tract when we administrated high dose of thyroid hormone. One GMC occurred from anal sides propagated to cardiac, and this propagation was similar to the emesis-like interdigestive motor activity, the other GMC occurred from oral sides propagated to anal sides and this was similar to the diarrhea-like interdigestive motor activity. We examined the relationship between thyroid function and gastrointestinal hormones including of ghrelin, GLP-1, and cholecystokinin (CCK). However, we could not find significant differences under different thyroid hormone status. This is the first report that thyroid hormone activated upper gastrointestinal motility without mediating gastrointestinal hormones.

Clinical features of hypermagnesemia in patients with functional constipation taking daily magnesium oxide

Although magnesium oxide is widely used as a laxative, alterations in serum magnesium concentrations among patients taking daily magnesium oxide have not been clarified. The present retrospective, cross-sectional study investigated the risk factors for hypermagnesemia in patients taking daily oral magnesium oxide. Of 2,176 patients administered daily magnesium oxide, 193 (8.9%) underwent assays of serum magnesium concentrations and were evaluated. High serum magnesium concentration and hypermagnesemia were defined as serum magnesium concentrations ≥2.5 mg/dl and ≥3.0 mg/dl, respectively. Of the 193 patients taking daily magnesium oxide, 32 (16.6%) had high serum magnesium concentration and 10 (5.2%) had hypermagnesemia. Factors associated with hypermagnesemia included chronic kidney disease (CKD) grade 4 (p = 0.014) and magnesium oxide dosage (p = 0.009). Factors associated with high serum magnesium concentration included magnesium oxide dosage >1,000 mg/day (p = 0.004), CKD grades 4 (p = 0.000) and concomitant use of stimulant laxatives (p = 0.035). Age, however, was not associated with hypermagnesemia or high serum magnesium concentration. In conclusion, renal function and magnesium oxide dosage, but not age, were associated with hypermagnesemia and high serum magnesium concentration in patients with functional constipation taking daily magnesium oxide.

Radionuclide Esophageal Transit Scintigraphy in Primary Hypothyroidism

Background/Aims

Esophageal dysmotility is associated with gastrointestinal dysmotility in various systemic and neuroregulatory disorders. Hypothyroidism has been reported to be associated with impaired motor function in esophagus due to accumulation of glycosaminoglycan hyaluronic acid in its soft tissues, leading to changes in various contraction and relaxation parameters of esophagus, particularly in the lower esophageal sphincter. In this study we evaluated esophageal transit times in patients of primary hypothyroidism using the technique of radionuclide esophageal transit scintigraphy.

Methods

Thirty-one patients of primary hypothyroidism and 15 euthyroid healthy controls were evaluated for esophageal transit time using 15-20 MBq of Technetium-99m sulfur colloid diluted in 10-15 mL of drinking water. Time activity curve was generated for each study and esophageal transit time was calculated as time taken for clearance of 90% radioactive bolus from the region of interest encompassing the esophagus. Esophageal transit time of more than 10 seconds was considered as prolonged.

Results

Patients of primary hypothyroidism had a significantly increased mean esophageal transit time of 19.35 ± 20.02 seconds in comparison to the mean time of 8.25 ± 1.71 seconds in healthy controls (P < 0.05). Esophageal transit time improved and in some patients even normalized after treatment with thyroxine. A positive correlation (r = 0.39, P < 0.05) albeit weak existed between the serum thyroid stimulating hormone and the observed esophageal transit time.

Conclusions

A significant number of patients with primary hypothyroidism may have subclinical esophageal dysmotility with prolonged esophageal transit time which can be reversible by thyroxine treatment. Prolonged esophageal transit time in primary hypothyroidism may correlate with serum thyroid stimulating hormone levels.

The real malady of Marcel Proust and what it reveals about diagnostic errors in medicine

Marcel Proust, author of À La Recherche du Temps Perdu, was considered a hypochondriac not only by the numerous specialists he consulted during his lifetime but also by every literary critic who ventured an opinion on his health, among them several clinicians. However, Proust's voluminous correspondence, as detailed in its attention to his every symptom as his novel, provides valuable clues to Proust's real, organic, and rare illness. Proust, in fact, was not only genuinely ill but far sicker than he even he believed, most likely suffering from the vascular subtype of Ehlers-Danlos Syndrome. Ironically, Proust's own doctors and his clinician-critics replicated the same kinds of diagnostic errors clinicians still routinely make today, shedding light on the plight of patients with rare illnesses.

Esophagus motility in overt hypothyroidism

PURPOSE

Gastrointestinal tract is one of the most affected systems in hypothyroidism. Despite decreased esophageal emptying, prolonged esophageal and gastric transit time have been indicated in previous reports, the mechanism of thyroid hormones activity and antibodies on the esophagus motility is not yet fully understood. This study was conducted to evaluate the esophagus motility by manometry in hypothyroid patients.

METHODS

The study enrolled with 28 overt, newly diagnosed hypothyroid patients and 29 age- and sex-matched healthy controls. Twenty-one females and 7 males with overt hypothyroidism and 22 females and 7 males with healthy control subjects were recruited to study. Esophageal manometry was performed using MMS (Medical Measurement Systems bv. The Netherlands) Solar GI-Air-Charged Intelligent Gastrointestinal Conventional Manometry.

RESULTS

The lower esophageal sphincter pressure (LESP) was 19.5 ± 6.5 mmHg in hypothyroid patients and 17.48 ± 4.65 mmHg in controls, and there was no significant difference (p = 0.18). Percentage of relaxation was 61.5 and 80.9 %, and it was significantly lower in hypothyroid patients than controls (p < 0.001). Additionally, duration of relaxation was found 3.85 ± 2.3 and 5.5 ± 2.28 s in patients and controls, respectively (p = 0.009). In patient group, LESP was positively correlated with fT3 (p = 0.033), and the duration of the contraction was negatively correlated with fT4 (p = 0.044).

CONCLUSION

In this study, we observed that hypothyroid state can affect esophagus motility via shortened duration of relaxation and reduced percentage of relaxation even if in patients without any gastrointestinal symptoms. Further studies are needed to clarify the effect of thyroid hormones on esophagus motility.

Hypothyroidism is a rare cause of isolated constipation

The prevalence of constipation in children is high and accounts for a large percentage of pediatric and pediatric gastroenterology visits. Thyroid testing is frequently ordered to evaluate constipation and other gastrointestinal complaints in children. We reviewed all of the patients with thyroid testing ordered by our pediatric gastroenterology division during a 5-year period. We found 873 patients on whom thyroid testing was performed, and 56 patients had evidence of hypothyroidism. Nine patients had constipation and clinically significant hypothyroidism in this group; however, only 1 child had constipation as their sole presenting symptom. The contribution of occult hypothyroidism to isolated constipation in children may have been previously overestimated.

Gastroparesis: pathogenesis, diagnosis and management

Gastroparesis is a prevalent condition that produces symptoms of delayed gastric emptying in the absence of physical blockage. The most common etiologies of gastroparesis are idiopathic, diabetic, and postsurgical disease, although some cases stem from autoimmune, paraneoplastic, neurologic or other conditions. Histologic examination of gastric tissues from patients with severe gastroparesis reveals heterogeneous and inconsistent defects in the morphology of enteric neurons, smooth muscle and interstitial cells of Cajal, and increased levels of inflammatory cells. Diagnosis is most commonly made by gastric emptying scintigraphy; however, wireless motility capsules and nonradioactive isotope breath tests have also been validated. A range of treatments have been used for gastroparesis including dietary modifications and nutritional supplements, gastric motor stimulatory or antiemetic medications, endoscopic or surgical procedures, and psychological interventions. Most treatments have not been subjected to controlled testing in patients with gastroparesis. The natural history of this condition is poorly understood. Active ongoing research is providing important insights into the pathogenesis, diagnosis, treatment and outcomes of this disease.

The thyroid and the gut

Thyroid disease is common, and its effects on the gastrointestinal system are protean, affecting most hollow organs. Hashimoto disease, the most common cause of hypothyroidism, may be associated with an esophageal motility disorder presenting as dysphagia or heartburn. Dyspepsia, nausea, or vomiting may be due to delayed gastric emptying. Abdominal discomfort, flatulence, and bloating occur in those with bacterial overgrowth and improve with antibiotics. Reduced acid production may be due to autoimmune gastritis or low gastrin levels. Constipation may result from diminished motility, leading to an ileus, megacolon, or rarely pseudoobstruction. Ascites in myxedema is characterized by a high protein concentration. Graves' disease accounts for 60% to 80% of thyrotoxicosis. Hyperthyroidism is accompanied by normal gastric emptying with low acid production, partly due to an autoimmune gastritis with hypergastrinemia. Transit time from mouth to cecum is accelerated, resulting in diarrhea. Steatorrhea is due to hyperphagia and stimulation of the adrenergic system. Diarrhea in medullary carcinoma of the thyroid (MCT) may be due to elevated calcitonin, prostaglandins, or 5-hydroxyindoleacetic acid. Ileal or colonic function may be abnormal. The esophagus may be compressed by benign processes, but more often by malignancies. MRI and CT scans are the best diagnostic modalities. The gastrointestinal manifestations of thyroid disease are generally due to reduced motility in hypothyroidism, increased motility in hyperthyroidism, autoimmune gastritis, or esophageal compression by a thyroid process. Symptoms usually resolve with treatment of the thyroid disease.

Aging and intestinal motility: a review of factors that affect intestinal motility in the aged

Normal aging is associated with significant changes in the function of most organs and tissues. In this regard, the gastrointestinal tract is no exception. The purpose of this review is to detail the important age-related changes in motor function of the various parts of the gastrointestinal tract and to highlight some of the important motility changes that may occur, either in relation to common age-related disorders, or as a result of certain drugs commonly prescribed in the aged. A major confounding factor in the interpretation of motor phenomena throughout the gastrointestinal tract in this age group is the frequent coexistence of neurological, endocrinological and other disease states, which may be independently associated with dysmotility. Overall, current data are insufficient to implicate normal aging as a cause of dysmotility in the elderly. Normal aging is associated with various changes in gastrointestinal motility, but the clinical significance of such changes remains unclear. More important is the impact of various age-related diseases on gastrointestinal motility in the elderly: for example, long-standing diabetes mellitus may reduce gastric emptying in up to 50% of patients; depression significantly prolongs whole-gut transit time; hypothyroidism may prolong oro-caecal transit time; and chronic renal failure is associated with impaired gastric emptying. In addition, various, frequently used drugs in the elderly cause disordered gastrointestinal motility. These drugs include anticholinergics, especially antidepressants with an anticholinergic effect, opioid analgesics and calcium antagonists.

Lactose intolerance following antithyroid drug medications

We recently observed 2 lactase-deficient women with Graves' disease who consistently developed severe diarrhea after ingestion of thionamide (methimazole and propylthiouracil) tablets containing lactose as carrier. The strict temporal relationship between ingestion of lactose-containing tablets and appearance of intestinal symptoms, as well as the absence of side effects following ingestion of methimazole tablets without lactose as carrier, provided the clue for the diagnosis. To our knowledge, severe diarrhea resulting from carrier lactose has not been previously reported for antithyroid drugs, and should be considered in occasional cases of patients with gastrointestinal symptoms on thionamide therapy.

Case report: reversible gastroparesis in patients with hypopituitary disease

A 72-year-old woman with chronic fatigue, malaise, weight loss, nausea, and vomiting was treated unsuccessfully for gastroparesis for more than 2 years. Clinical and biochemical features of hypopituitary disease and symptoms of a nonsecreting pituitary tumor had been overlooked and became apparent only after the differential diagnosis of hyponatremia was considered. Transsphenoidal resection of the pituitary tumor and appropriate 1-thyroxine and hydrocortisone replacement returned her gastric emptying time to normal and relieved her symptoms. Primary and secondary deficits of l-thyroxine and cortisol should be considered when making a possible diagnosis of gastroparesis.

Colorectal manifestations of endocrine disease

PURPOSE

The aim of this review is to alert the colon and rectal surgeon to the colorectal manifestations of endocrine disease.

METHODS

This report was obtained by a review of the medical literature. Endocrine disease may initially present as a symptom felt to be referable to colorectal disease. Furthermore symptoms of well-established endocrine disorders may have refractory colorectal symptoms.

RESULTS

Constipation is the most common gastrointestinal symptom of diabetics; however, in patients with brittle diabetes, diarrhea may be chronic and intermittent. Unexplained diarrhea, despite an exhaustive work-up for an etiology, should alert the clinician to the possibility of a pancreatic endocrine tumor. Thyroid disorders, depending on activity of the gland, may have refractory constipation, diarrhea, or steatorrhea as the only presenting symptoms. Constipation is a common symptom of hypercalcemia, secondary to hyperparathyroidism. Primary hyperparathyroidism has been associated with increased incidence of malignancies, specifically of colonic origin. In patients with acromegaly a threefold to eightfold increased risk of colon carcinoma or adenomatous polyps is seen. Chronic adrenal insufficiency may present initially as diarrhea and malabsorption. The adrenal gland is a frequent site of metastases from colorectal cancer. Pheochromocytomas may be a cause of occult gastrointestinal bleeding or ischemic colitis.

CONCLUSION

Unexplained symptoms referable to the colon and rectum should alert the clinician to the possibility of an underlying endocrine disorder.

Pharmacokinetic considerations in gastrointestinal motor disorders

Although it has been recognised that alterations in gastrointestinal motility, whether induced by physiological or pathological processes, have significant effects on the pharmacokinetics of orally administered drugs, this subject has received inappropriately little attention. Studies relating to this topic have focused on healthy volunteers and animals and have largely been confined to the effects of single drug doses. There is limited information about the effects of disease on pharmacokinetics under steady-state conditions. Changes in gastrointestinal motility may affect the pharmacokinetics of orally administered drugs by altering the rate of delivery, bioavailability or mucosal absorption of the drug. In general the rate of absorption and time taken to achieve maximal plasma concentrations for well absorbed drugs may be modified by changes in gastrointestinal motility, but overall bioavailability is not usually affected. In these cases the therapeutic and clinical effects of the alteration in pharmacokinetics will, therefore, depend on which parameters are important for the action of the drug. For poorly absorbed drugs both the rate of absorption and bioavailability are likely to be altered by changes in gastrointestinal motility. However, the complex effects of food and disease, as well as the properties and formulation of any drug (solubility, ease of dispersion, delayed release formulation) often make the prediction of the magnitude, or even the direction, of any effect difficult to predict. Drugs with direct effects on gastrointestinal motility may influence their own patterns of absorption. In patients with gastrointestinal motility disorders, drugs administered in a controlled release formulation, or those with poor bioavailability, are most likely to have a poorly predictable therapeutic effect. Care should be taken to ensure that the formulation of the drug, its timing of administration in relation to meals and the use of coadministered drugs optimise, or at least ensure consistent absorption.

Decreased orocaecal transit time, as measured by the exhalation of hydrogen, in hyperthyroid cats

Orocaecal transit time was assessed in healthy cats and cats with hyperthyroidism by means of the breath hydrogen test using a standard liquid meal with lactulose. The median transit time in 10 healthy cats was 98 minutes (range 60 to 150 minutes) and 90 minutes (range 75 to 150 minutes) in a repeated assessment. The median transit time in 10 cats with hyperthyroidism was 53 minutes (range 45 to 150 minutes) which was significantly more rapid (P < 0.05) than in the healthy cats.

Use of breath hydrogen measurement to evaluate orocecal transit time in cats before and after treatment for hyperthyroidism

Orocecal transit time was evaluated in 13 cats diagnosed with hyperthyroidism. Transit was determined by measuring the change in breath hydrogen and methane concentrations following oral administration of a nonabsorbable carbohydrate (lactulose). Transit times before and three to four weeks after treatment of the hyperthyroidism with radioactive iodine were compared. There was a significant prolongation of transit time, as determined by a change in hydrogen concentration, following correction of the hyperthyroidism (p = 0.034). Average transit times and standard errors were 27.7 +/- 3.7 minutes before treatment and 56.5 +/- 12.1 minutes after treatment. Methane was not detected in any of the samples. Hyperthyroidism appears to be associated with an accelerated small intestinal transit time in cats.

The effect of short-term dietary fibre administration on oro-caecal transit time in dogs

The effect on oro-caecal transit time of addition of soluble (guar gum) and insoluble (wheat bran) fibre to diets fed to seven healthy dogs at levels that have been shown to reduce post-prandial hyperglycaemia was assessed. Oro-caecal transit time was measured by sequential analysis of exhaled breath hydrogen levels. Median oro-caecal transit times were 105 min (range: 45 to 135), 113 min (range: 53 to 203) and 105 min (range: 75 to 195) after administration of a 770 g standard meal of canned food alone, or with the addition of 7.7 g wheat bran or guar gum, respectively. There was no significant difference between the oro-caecal transit times (p = 0.964) for the different diets when the results for all the dogs were pooled. The difference between diets was statistically significant for both maximal post-prandial hyperglycaemia (p = 0.035) and area of post-prandial hyperglycaemia under the post-prandial glucose curve (p = 0.006).

The effect of thyroxine on small intestinal motility in the elderly

OBJECTIVE

To study the effects of thyroxine on orocaecal transit time in a group of elderly hypothyroid patients on long-term thyroxine replacement therapy.

DESIGN

Measurement of the effect of withdrawal and subsequent replacement of thyroxine replacement therapy on orocaecal transit time.

PATIENTS

Fifteen elderly, previously hypothyroid patients on full replacement therapy with oral thyroxine were studied. There were 11 females and four males, aged 60-94 years (median 78 years) receiving initially 50-200 micrograms of oral thyroxine daily (median 100 micrograms).

MEASUREMENTS

Serum TSH and FT4 were measured by radioimmunoassay and orocaecal transit time assessed using a lactulose hydrogen breath test. These tests were repeated 7 days after withdrawal of thyroxine replacement and again 7 days after subsequent reinstatement of therapy.

RESULTS

On withdrawal of therapy, the median transit time increased from 75.0 to 135 minutes (P less than 0.01), the median TSH increased from 1.8 to 2.3 mU/l (P = NS) and the median FT4 decreased from 13.7 to 10.6 pmol/l (P less than 0.01). On reinstatement of therapy, the median transit time decreased to 95 minutes (P = NS), the median TSH decreased to 1.1 mU/l (P = NS) and the median FT4 increased to 14.1 pmol/l (P less than 0.01).

CONCLUSIONS

These findings demonstrate the sensitivity of the small bowel to changes in thyroid hormone status and suggest that constipation arising as a result of this hypomotility may well be an early physical manifestation of hypothyroidism.

Effect of erythromycin on the oro-caecal transit time in man

Erythromycins often cause gastrointestinal side-effects due to an increase in motility or to change in the intestinal bacterial flora. In order to evaluate the effect of erythromycin on gastrointestinal motility. 11 healthy volunteers were given placebo, erythromycin stearate (ES) 1000 mg or a therapeutically equivalent single dose of erythromycin acistrate (EA.2'-acetyl erythromycin stearate) 800 mg in a double-blind trial. The oro-caecal transit time was measured using the hydrogen breath test with lactulose as the substrate. The transit time was estimated from the H2-peak (ppm) in end-expiratory breath by two methods, t1 representing the "front" and t2 the "bulk" of lactulose reaching the colon. t1 was 51 min in the placebo group, 38 min in the EA and 31 min in the ES group (p less than 0.05, ES vs placebo). t2 was 74 min, 64 min, and 46 min, respectively (p less than 0.05, ES vs placebo). The difference between EA and ES was also significant. Six subjects in the ES group but none in the EA group recorded adverse gastrointestinal effects attributable to medication. It was concluded that erythromycin shortens the oro-caecal transit time in man and that EA effects the transit time slightly less than ES.