Radionuclide Esophageal Transit Scintigraphy in Primary Hypothyroidism

Area of Science:

• Gastroenterology
• Endocrinology

Background:

• Esophageal dysmotility is often associated with gastrointestinal issues in systemic and neuroregulatory disorders.
• Hypothyroidism can impair esophageal motor function due to glycosaminoglycan buildup, affecting esophageal contraction and relaxation, particularly the lower esophageal sphincter.

Purpose of the Study:

• To evaluate esophageal transit times in patients with primary hypothyroidism.
• To assess the impact of thyroxine treatment on esophageal transit.
• To explore the correlation between esophageal transit time and serum thyroid stimulating hormone levels.

Main Methods:

• Radionuclide esophageal transit scintigraphy was used to assess 31 primary hypothyroidism patients and 15 controls.
• A radioactive tracer (Technetium-99m sulfur colloid) was administered orally.
• Esophageal transit time was calculated based on the clearance of the radioactive bolus.

Main Results:

• Patients with primary hypothyroidism exhibited significantly prolonged mean esophageal transit time (19.35 ± 20.02 seconds) compared to controls (8.25 ± 1.71 seconds).
• Esophageal transit time improved or normalized in some patients after thyroxine treatment.
• A weak positive correlation was observed between serum thyroid stimulating hormone levels and esophageal transit time.

Conclusions:

• Subclinical esophageal dysmotility with prolonged transit time is common in primary hypothyroidism and is reversible with thyroxine therapy.
• Prolonged esophageal transit time in hypothyroidism may be associated with serum thyroid stimulating hormone levels.