Enteric hyperoxaluria, recurrent urolithiasis, and systemic oxalosis in patients with Crohn's disease.

Background: Prevalence of recurrent calcium-oxalate (CaOx) urolithiasis (UL) is up to fivefold higher in Crohn's disease than in the general population. Treatment options are scarce and the risk of recurrent UL or progressive renal CaOx deposition, (oxalosis) based early end-stage renal failure (ESRF), subsequent systemic oxalosis, and recurrence in the kidney graft is pronounced. We aimed to find proof that secondary hyperoxaluria is the main risk factor for the devastating course and correlates with intestinal oxalate absorption.

Hyperoxaluria, hypocitraturia, hypomagnesiuria, and lack of intestinal colonization by Oxalobacter formigenes in a cervical spinal cord injury patient with suprapubic cystostomy, short bowel, and nephrolithiasis.

Although urolithiasis is common in spinal cord injury patients, it is presumed that the predisposing factors for urinary stones in spinal cord injury patients are immobilization-induced hypercalciuria in the initial period after spinal injury and, in later stages, urine infection by urease-producing micro-organisms, e.g., Proteus sp.

Intestinal oxalate absorption is higher in idiopathic calcium oxalate stone formers than in healthy controls: measurements with the [(13)C2]oxalate absorption test.

Purpose: We assessed the importance of oxalate hyperabsorption for idiopathic calcium oxalate urolithiasis, oxalate absorption in healthy volunteers and recurrent calcium oxalate stone formers was compared.

Materials And Methods: The [(13)C2]oxalate absorption test, a standardized, radioactivity-free test, was performed. On 2 days 24-hour urine was collected and an identical standard diet containing 800 mg Ca daily was maintained.

Effect of oxalate test dose size on absolute and percent oxalate absorption.

The purpose of this pilot study was to establish the dependence or independence of oxalate absorption on the quantity of the test dose of sodium oxalate over a range of test doses corresponding to physiological dietary oxalate intake values. Gastrointestinal oxalate absorption was measured with the [13C2]oxalate absorption test. Six healthy volunteers were always tested under standardized dietary conditions with 63 mg dietary oxalate and 800 mg dietary calcium per day.

Intestinal oxalate absorption in patients with continent urinary diversion.

The objective of the study is to evaluate the post-operative effect of an orthotopic ileal neobladder or a Mainz pouch I bladder replacement on the extent of intestinal oxalate absorption. Gastrointestinal oxalate absorption was measured in six patients with an orthotopic ileal neobladder and in six patients with a Mainz pouch I bladder replacement. The function test applied was the [13C2]oxalate absorption test.

Influence of a high-oxalate diet on intestinal oxalate absorption.

Hyperoxaluria is a major risk factor for renal stones. In most cases, it is sustained by increased dietary loads. In healthy individuals with a normal Western diet, the majority of urinary oxalate is usually derived from endogenous metabolism.

Absorptive hyperoxaluria leads to an increased risk for urolithiasis or nephrocalcinosis in cystic fibrosis.

Background: Hyperoxaluria has been incriminated to account for the increased incidence of urolithiasis or nephrocalcinosis in patients with cystic fibrosis (CF). Hyperoxaluria presumably is caused by fat malabsorption and the absence of such intestinal oxalate-degrading bacteria as Oxalobacter formigenes. To better elucidate its pathophysiological characteristics, we prospectively studied patients with CF by determining these parameters and performing renal ultrasonography twice yearly.

The efficacy of dietary intervention on urinary risk factors for stone formation in recurrent calcium oxalate stone patients.

Purpose: Nutrition is suggested to be the major environmental risk factor in idiopathic calcium oxalate stone disease. The study was designed to evaluate the effect of dietary intervention on urinary risk factors for recurrence in calcium oxalate stone formers.

Materials And Methods: A total of 76 men and 31 women with idiopathic calcium oxalate stone disease collected 24-hour urine on their habitual, self-selected diets and after 7 days on a balanced standardized diet according to the recommendations for calcium oxalate stone formers.

Importance of magnesium in absorption and excretion of oxalate.

Introduction: Magnesium treatment for calcium oxalate urolithiasis is discussed controversially. The aim of this study was to investigate the influence of magnesium supplementation on the oxalate absorption.

Materials And Methods: The [13C2]oxalate absorption test was always performed three times in 6 healthy volunteers under standardized conditions, with one 10-mmol magnesium supplement together with the labeled oxalate and with two 10-mmol magnesium supplements given in 12-hour intervals.

The effect of oral administration of calcium and magnesium on intestinal oxalate absorption in humans.

Calcium oxalate (CaOx) urolithiasis is the most common urinary stone disease (70-75 % of all stones consist of CaOx in countries with western diet). Oxalate is the most lithogenic substance in CaOx crystallisation in urine. Oxalate is either synthesized within the body or absorbed from food.

Dependence of oxalate absorption on the daily calcium intake.

Two to 20% of ingested oxalate is absorbed in the gastrointestinal tract of healthy humans with a daily 800 mg calcium intake. Calcium is the most potent modifier of the oxalate absorption. Although this has been found repeatedly, the exact correlation between calcium intake and oxalate absorption has not been assessed to date.

Reference range for gastrointestinal oxalate absorption measured with a standardized [13C2]oxalate absorption test.

Purpose: Hyperoxaluria is a prominent risk factor for calcium oxalate urinary stones. Oxalate in urine is synthesized in the body or absorbed from food in the gastrointestinal tract. The amount of oxalate absorbed by patients with calcium oxalate stones may vary from a few percent to 50% of the dietary intake.