Thyroid Function and Insulin Sensitivity Before and After Bilio-pancreatic Diversion

Abstract

BPD increases the prevalence of subclinical or even frank hypothyroidism, without causing a defect in thyroid function itself, through several integrated mechanisms. (1) It induces iodine malabsorption, which is partially compensated by iodine excretion contraction. (2) The entero-hepatic open circulation determines fT3 loss, which induces subclinical or frank hypothyroidism in patients with pre-existing thyroid alterations, interfering also with the weight loss progress. Iodine supplementation should be recommended in those patients reporting thyroid alterations at the sonogram prior to BPD, LT4 therapy should be strictly monitored in patients suffering of subclinical hypopthiroidism and T3 therapy should eventually be considered for patients diagnosed with frank hypothyroidism prior to BPD.

Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report

“…It is important to note that lean body mass is a better standard to gauge thyroxine requirements than weight. Rapid weight loss due to serious illness (e.g., certain malignancies, AIDS, malnutrition, and bariatric surgery) has also been associated with oral levothyroxine homeostasis [ 73 ]. Poor conversion of T4 to T3 It has been suggested that a genetic variation in deiodinase D2 (also called type 2 deiodinase, or 5′-deiodinase) may help to explain why some patients who fail to achieve control of hypothyroidism with a background of levothyroxine therapy respond to natural desiccated thyroid or to the combined therapy of levothyroxine and synthetic T3 [ 74 ].…”

“…Rapid weight loss due to serious illness (e.g., certain malignancies, AIDS, malnutrition, and bariatric surgery) has also been associated with oral levothyroxine homeostasis [ 73 ].…”

Thyroid disorders and gastrointestinal and liver dysfunction: A state of the art review

“…It has been reported that biliopancreatic diversion is associated with an increased prevalence of subclinical or even frank hypothyroidism through several integrated mechanisms including iodine malabsorption and increased free T3 losses through changes in the entero-hepatic circulation [92].…”

Effect of weight loss after gastric bypass surgery on thyroid function in euthyroid people with morbid obesity

“…In contrast to gastric bypass or banding, it has been reported that biliopancreatic diversion is associated with an increased prevalence of subclinical or even frank hypothyroidism through several integrated mechanisms including iodine malabsorption and increased fT3 losses through changes in the entero‐hepatic circulation (24). While we do not have data on iodine status in our retrospective cohort study, we anticipate that patients were iodine‐replete as they were routinely prescribed the multivitamin and micronutrient supplement, Forceval® (Alliance Pharma plc., Wiltshire, UK) that provides 140 µg of iodine (100% of reference nutrient intake for adults in the UK (25)).…”