Levothyroxine Therapy in Gastric Malabsorptive Disorders

Virili, Camilla; Brusca, Nunzia; Capriello, Silvia; Centanni, Marco

doi:10.3389/fendo.2020.621616

Cited by 29 publications

(23 citation statements)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both these factors affect the pH–sensitive fraction of T4 absorption [ 53 ]. This implies that any food altering the gastric pH during the first hour from the ingestion of levothyroxine [ 12 , 16 , 19 , 20 ] may prevent the optimal absorption of LT4, leading to an increased need for therapeutic dose of the hormone [ 54 ].…”

Section: Discussionmentioning

confidence: 99%

Levothyroxine treatment and gastric juice pH in humans: the proof of concept

Virili

Bruno

Santaguida³

et al. 2022

Endocrine

Self Cite

View full text Add to dashboard Cite

Purpose Despite the absorption of oral thyroxine (T4) occurs in the small bowel, several patients with gastric disorders show an increased need for T4. In vitro evidence suggested that medium pH variations interfere with T4 dissolution. This study was aimed at finding the proof of concept of a direct relationship between the minimal effective dose of T4 and the actual gastric juice pH. Patients and methods Among 311 consecutively thyroxine-treated patients, 61 bearing Hashimoto’s thyroiditis (52 F/9 M; median age = 51 years) who complained persistent dyspepsia and/or upper abdominal symptoms following a noninvasive workup for gastrointestinal disorders, underwent EGDS with multiple biopsies and gastric juice pH measurement. All patients accepted to take thyroxine in fasting conditions, abstaining from eating or drinking for one hour. Results Thyroxine requirement increased along with the rising gastric pH (ρ = 0.4229; p = 0.0007). A multivariate analysis revealed that gastric pH was, beside body mass index, the far more important independent variable in determining the effective dose of T4 (p = 0.001). The ROC curve revealed that the pH threshold for an increased thyroxine requirement was at 2.28, being the AUC by 78%. Subdividing patients by the histologic findings, it appeared a significant increase (p = 0.0025) along with the progressive damage of gastric mucosa. Conclusion The in vivo measurement of gastric pH highlighted its key role in determining the minimal effective dose of oral T4 and may explain the interference of food, of some drugs and gut disorders on levothyroxine treatment

show abstract

Section: Discussionmentioning

confidence: 99%

Levothyroxine treatment and gastric juice pH in humans: the proof of concept

Virili

Bruno

Santaguida³

et al. 2022

Endocrine

Self Cite

View full text Add to dashboard Cite

show abstract

“…the presence of CAG under endoscopic follow-up; iii. the presence of positive predictors for CAG [current or previous history of H. pylori infection, the presence of antibodies to gastric parietal cells and/or anti-intrinsic factor, hypergastrinemia ( Lahner et al., 2020 ), unexplained iron deficiency or pernicious anemia ( Sibilla et al., 2008 ), thyroxine malabsorption in patients with hypothyroidism ( Virili et al., 2021 )]; iv. dyspepsia or gastroesophageal reflux disease (GERD) symptoms ( Carabotti et al., 2017 ).…”

Section: Methodsmentioning

confidence: 99%

The Potential Role of Hypochlorhydria in the Development of Duodenal Dysbiosis: A Preliminary Report

Filardo

Scalese

Virili

et al. 2022

Front. Cell. Infect. Microbiol.

Self Cite

View full text Add to dashboard Cite

In recent years, the role of gastric and duodenal microbiota has acquired increasing importance in the homeostasis of the host, although, to date, most evidence concern the faecal microbiota. Indeed, the gastric, and duodenal microbiota are challenging to study, due to gastric acid, bile, digestive enzymes, and rapid transit time. Specifically, the gastric acid environment may influence their bacterial composition since the acid barrier protects against orally ingested microorganisms and leads to their inactivation before reaching the intestine. The aim of this study was to assess a correlation between intragastric pH and gastric as well as intestinal microbiota of patients with histologic gastric alterations. pH was measured in the gastric juice and the bacterial composition in gastric and duodenal biopsies and faecal samples, was investigated via 16s rRNA gene sequencing. The main result is the direct correlation of duodenal microbiota biodiversity, via alpha diversity measures, with intragastric pH values. In particular, patients with hypochlorhydria showed increased duodenal microbiota biodiversity, higher intragastric pH values being prevalent in patients with chronic atrophic gastritis. Lastly, the latter was also strongly associated to the presence of oral bacteria, like Rothia mucilaginosa, Streptococcus salivarius and Granulicatella adiacens, in the duodenal microbiota. In conclusions, our results suggest a low-acid gastric environment as a contributive factor for duodenal dysbiosis, potentially leading to the development of pathological conditions of the gastrointestinal tract.

show abstract

“…Levothyroxine has a narrow therapeutic index [19]. It is absorbed in the small intestine and its bioavailability is reduced by food; hence, it is also recommended that levothyroxine be administered in the fasting state [20][21][22].…”

Section: Introductionmentioning

confidence: 99%