oxalates and Weight-Loss

Kidney stones are a common complication of hyperoxaluria. The aim of this study is to investigate the protective and preventive effects of Ulva lactuca aqueous extract, ulvan polysaccharides and atorvastatin on ethylene glycol-induced hyperoxaluria.. Male Wistar rats between 110 and 145 g in weight were used in the study, Ulva lactuca aqueous extract and polysaccharides were prepared. The male albino rats were supplemented with 0.75 percent ethylene glycol (v/v) in their drinking water for six weeks to induce hyperoxaluria. Ulvan infusions (100 mg/kg body weight), ulvan polysaccharides (100 mg/kg body weight), and atorvastatin (two milligrams/kg body weight) to treat hyperoxaluric rats for four weeks (every other day) were used. Weight loss, serum creatinine, serum urea, serum uric acid, serum oxalate, kidney oxalate, kidney lipid peroxidation, and kidney DNA fragmentation and kidney histopathological studies were done.. Weight loss, rise of serum creatinine, serum urea, serum uric acid, serum oxalate, kidney oxalate, kidney lipid peroxidation, and kidney DNA fragmentation were all shown to be prevented by the addition of atorvastatin, polysaccharides, or aqueous extract, respectively. Catalase (CAT) activity, glutathione peroxidase (GPX) activity, glutathione-S-transferase (GST) activity, and histopathological perturbations were all significantly reduced by the medicines that were studied.. Hyperoxaluria caused by ethylene glycol may be prevented by a combination of Ulva lactuca aqueous extract, ulvan polysaccharides, and atorvastatin. A reduction in renal oxidative stress and an improvement of the antioxidant defense system may be responsible for these protective benefits. However, Ulva lactuca infusion and ulvan polysaccharides need to be studied further in humans, in order to determine their efficacy and safety.

Topics: Animals; Antioxidants; Atorvastatin; Body Weight; Creatinine; Ethylene Glycol; Humans; Hyperoxaluria; Kidney; Male; Oxalates; Polysaccharides; Rats; Rats, Wistar; Ulva; Urea; Uric Acid; Weight Loss

Hyperoxaluria and oxalate kidney stones frequently develop after Roux-en-Y gastric bypass (RYGB). Oxalobacter formigenes can degrade ingested oxalate.. Examine the effect of O. formigenes wild rat strain (OXWR) colonization on urinary oxalate excretion and intestinal oxalate transport in a hyperoxaluric RYGB model.. Basic Science Laboratory, United States.. At 21 weeks of age, 28 obese male Sprague-Dawley rats survived Sham (n = 10) or RYGB (n = 18) surgery and were maintained on a 1.5% potassium oxalate, 40% fat diet. At 12 weeks postoperatively, half the animals in each group were gavaged with OXWR. At 16 weeks, percent dietary fat content was lowered to 10%. Urine and stool were collected weekly to determine oxalate and colonization status, respectively. At week 20, [14 C]-oxalate fluxes and electrical parameters were measured in vitro across isolated distal colon and jejunal (Roux limb) tissue mounted in Ussing Chambers.. RYGB animals lost 22% total weight while Shams gained 5%. On a moderate oxalate diet, urinary oxalate excretion was 4-fold higher in RYGB than Sham controls. OXWR colonization, obtained in all gavaged animals, reduced urinary oxalate excretion 74% in RYGB and 39% in Sham and was further augmented by lowering the percentage of dietary fat. Finally, OXWR colonization significantly enhanced basal net colonic oxalate secretion in both groups.. In our model, OXWR lowered urinary oxalate by luminal oxalate degradation in concert with promotion of enteric oxalate elimination. Trials of O. formigenes colonization and low-fat diet are warranted in calcium oxalate stone formers with gastric bypass and resistant hyperoxaluria.

Topics: Animals; Creatinine; Disease Models, Animal; Eating; Feces; Gastric Bypass; Hyperoxaluria; Male; Obesity, Morbid; Oxalates; Oxalobacter formigenes; Random Allocation; Rats, Sprague-Dawley; Weight Loss

Hyperoxaluria and increased calcium oxalate stone formation occur after Roux-en-Y gastric bypass (RYGB) surgery for morbid obesity. The etiology of this hyperoxaluria is unknown. We hypothesized that after bariatric surgery, intestinal hyperabsorption of oxalate contributes to increases in plasma oxalate and urinary calcium oxalate supersaturation.. We prospectively examined oxalate metabolism in 11 morbidly obese subjects before and 6 and 12 months after RYGB (n = 9) and biliopancreatic diversion-duodenal switch (BPD-DS) (n = 2). We measured 24-hour urinary supersaturations for calcium oxalate, apatite, brushite, uric acid, and sodium urate; fasting plasma oxalate; 72-hour fecal fat; and increases in urine oxalate following an oral oxalate load.. Six and 12 months after RYGB, plasma oxalate and urine calcium oxalate supersaturation increased significantly compared with similar measurements obtained before surgery (all P ≤ .02). Fecal fat excretion at 6 and 12 months was increased (P = .026 and .055, 0 vs 6 and 12 months). An increase in urine oxalate excretion after an oral dose of oxalate was observed at 6 and 12 months (all P ≤ .02). Therefore, after bariatric surgery, increases in fecal fat excretion, urinary oxalate excretion after an oral oxalate load, plasma oxalate, and urinary calcium oxalate supersaturation values were observed.. Enteric hyperoxaluria is often present in patients after the operations of RYGB and BPD-DS that utilize an element of intestinal malabsorption as a mechanism for weight loss.

Topics: Adult; Aged; Calcium Oxalate; Dietary Fats; Female; Follow-Up Studies; Gastric Bypass; Humans; Hyperoxaluria; Intestinal Absorption; Malabsorption Syndromes; Middle Aged; Nephrolithiasis; Obesity, Morbid; Oxalates; Postoperative Complications; Prospective Studies; Risk Factors; Weight Loss

Medical records of 56 patients who had undergone jejunoileal bypass (JIB) surgery because of morbid obesity were reviewed. The follow-up time varied from 3 to 25 years (average 16 years). Twenty-two of the 56 patients (39.3%) were found to have renal calculi. The interval between the operation and the occurrence or knowledge of the first stone formation ranged from some months to 19 years. The mean weight loss at 5 years was 36.5 kg. Renal function investigations showed no evidence that the jejunoileal bypass operation alters the renal function. The urinary excretion of oxalate was high: 1.112 mumol/24 h (normal range: 55-400 mumol/24 h), and citrate excretion was low: 1.48 mmol/24 h (normal range: 2-5 mmol/24 h). There was no difference in these respects between stone formers and non-stone formers.

Topics: Adult; Aged; Citric Acid; Female; Follow-Up Studies; Humans; Jejunoileal Bypass; Kidney Calculi; Kidney Function Tests; Male; Middle Aged; Oxalates; Postoperative Complications; Reference Values; Retrospective Studies; Weight Loss