Acute parathyroid hormone increase by oral peptones administration after roux-en-Y gastric bypass surgery in obese subjects: Role of phosphate in the rapid control of parathyroid hormone release

It is generally considered that changes in serum phosphate levels do not alter parathyroid hormone (PTH) secretion in the absence of concomitant changes in ionized serum calcium level in humans. An acute rise in PTH was shown after phosphate administration by intraduodenal gavage in rats. We aimed to study gastrin, phosphate, PTH, ionized calcium (iCa), and blood pH responses to oral peptones in morbidly obese patients before and after roux-en-Y gastric bypass (RYGB) surgery.These parameters were evaluated in response to an oral peptone load in 24 (18 male and 6 female) obese subjects before and 6 months after RYGB surgery. In 12 gastric bypass patients, we also evaluated PTH and phosphate …