Intestinal Absorption of Oxalate and Calcium in Patients with Jejunoileal Bypass

Abstract

Jejunoileal bypass (JIB) has been widely performed for treatment of excessive obesity. Formation of calcium oxalate stones is a common side effect. Since, under physiological conditions, the intestinal absorption of calcium and that of oxalate are interrelated, intestinal oxalate and calcium absorption were measured in the present study by isotope techniques in 19 JIB patients and 20 healthy controls. The JIB patients showed pronounced hyperoxaluria and markedly increased absorption of oxalate, with a urinary excretion of 14C-oxalate of 29 +/- 19% (controls 6.2 +/- 3.7%; p less than 0.001). There was a strong correlation between the intestinal absorption and urinary excretion of oxalate in the JIB patients (r = 0.72; p less than 0.001). Furthermore, their oxalate kinetics was altered, with continued urinary excretion of 14C-oxalate for up to 48 hours. The JIB patients also had reduced calcium absorption (36 +/- 9.1% vs. 47 +/- 9.0%; p less than 0.001) and patients with malabsorption of calcium and low urinary calcium had the highest intestinal absorption and urinary excretion of oxalate. It is concluded that hyperoxaluria in JIB patients is due to a significant extent to hyperabsorption of oxalate.

Pathophysiology of renal disease associated with liver disorders: Implications for liver transplantation. Part I

“…25 Jejunoileal bypass is associated with renal interstitial fibrosis. 13,26 Generic hepatic failure, independent of cause, also has been associated with renal histological changes. These changes usually are glomerular and have been labeled hepatic glomerulosclerosis.…”

True Fractional Calcium Absorption is Decreased After Roux‐En‐Y Gastric Bypass Surgery

“…Roux‐en‐Y gastric bypass (RYGB) 1 surgery is considered to be the gold standard alternative treatment for severe obesity because it should result in less severe malabsorption and complications than traditional malabsorptive procedures (i.e., jejuno‐ileal bypass) (1, 2, 3). The malabsorptive procedures have been recognized as a risk factor for developing bone disease (4, 5, 6, 7, 8, 9) as a result of altered calcium (Ca) metabolism and compromised Ca absorption (10, 11, 12, 13, 14, 15, 16). Only a few studies have investigated Ca absorption prospectively in jejuno‐ileal bypass patients and have shown that Ca absorption decreases by ∼50% after surgery (10, 13, 16).…”

Effect of dietary intake on urinary oxalate excretion in calcium renal stone formers

“…Usually, the absorption rate of oxalate from food is as low as 10% [5], yet the absorption rate increases with the ingestion of sodium oxalate [6]. The absorption rate of oxalate from the intestine changes with the source of food and the simultaneous intake of other food [7].…”