Gallbladder Motor Function in Patients with Different Thyroid Hormone Status

Abstract

Hypothyroidism and hyperthyroidism are known to affect cholesterol metabolism, bile acid synthesis and bile content. There are previous studies reporting increased prevalence of gallstone and common bile duct stone formation in hypothyroidism. The aim of this study was to compare gallbladder (GB) motor function between euthyroid, hypothyroid and hyperthyroid subjects by conventional ultrasonography. Eighteen euthyroid, 14 hypothyroid and 20 hyperthyroid, age, sex and body mass index matched subjects were included in the study. Etiology of hypothyroidism comprised of thyroidectomy, Hashimoto's thyroiditis and previous radioactive iodine therapy. Hyperthyroid group included patients with toxic nodular goitre and Graves' disease. Patients who have diseases or are under drug treatment known to affect biliary function were not included in the study. Fasting and post-stimulus GB volumes were measured by real-time conventional ultrasonography and computer unit (Aloka UST-979, 3.5 mHz electronic convex probe, Japan). No significant differences were noted for fasting, post-stimulus GB volumes and GB ejection fraction between euthyroid, hypothyroid and hyperthyroid subjects. Measuring GB motility accurately is not straightforward because besides being not static during fasting, after a meal, intermittent emptying and refilling of GB occurs. Ultrasonography is affected by GB filling and measures "net" GB emptying. Although cumbersome, additional evaluation with cholescintigraphy which detects "absolute" GB emptying and is not affected by GB filling may provide complete assessment of motor function and may be more informative in evaluating subjects with different thyroid hormone status.