Overweight and body fat are predictors of hypovitaminosis D in renal transplant patients.

Background: Hypovitaminosis D has been frequently reported after renal transplantation, but the impact of obesity and other factors in the reduction of vitamin D levels is not well established. We aimed to evaluate risk factors contributing to hypovitaminosis D among nondiabetic renal transplant recipients (RTR) with serum creatinine <2.0 mg/dL, at least 6 months after transplantation.

The effect of sodium bicarbonate upon urinary citrate excretion in calcium stone formers.

Objective: To evaluate the effects of oral sodium bicarbonate (NaBic) supplementation upon urinary citrate excretion in calcium stone formers (CSFs).

Methods: Sixteen adult calcium stone formers with hypocitraturia were enrolled in a randomized, double-blind, crossover protocol using 60 mEq/day of NaBic during 3 days compared to the same period and doses of potassium citrate (KCit) supplementation. Blood and 24-hour urine samples were collected at baseline and during the third day of each alkali salt.

Response to dietary oxalate after bariatric surgery.

Background And Objectives: Bariatric surgery (BS) may be associated with increased oxalate excretion and a higher risk of nephrolithiasis. This study aimed to investigate urinary abnormalities and responses to an acute oxalate load as an indirect assessment of the intestinal absorption of oxalate in this population.

Design, Setting, Participants, & Measurements: Twenty-four-hour urine specimens were collected from 61 patients a median of 48 months after BS (post-BS) as well as from 30 morbidly obese (MO) participants; dietary information was obtained through 24-hour food recalls.

Noncitrus alkaline fruit: a dietary alternative for the treatment of hypocitraturic stone formers.

Background And Purpose: Fruits and vegetables are natural suppliers of potassium, bicarbonate, or bicarbonate precursors such as citrate, malate and others-hence, possessing potential effects on citraturia. We aimed to compare the acute effects of a noncitrus (melon) fruit vs citric ones (orange and lime) on citraturia and other lithogenic parameters.

Patients And Methods: Two-hour urine samples were collected from 30 hypocitraturic stone-forming patients after an overnight fast and 2, 4, and 6 hours after the consumption of 385 mL (13 oz) of either freshly squeezed orange juice (n=10), freshly blended melon juice (n=10), or freshly squeezed lime juice (n=10).

Effects of calcium supplementation on body weight reduction in overweight calcium stone formers.

A randomized, placebo-controlled trial was conducted in overweight calcium stone-forming (CSF) patients, to evaluate the effect of calcium supplementation associated with a calorie-restricted diet on body weight (BW) and fat reduction and its potential changes upon serum and urinary parameters. Fifteen patients were placed on a hypocaloric diet for 3 months, supplemented with either calcium carbonate (CaCO(3), n = 8) or placebo (n = 7), 500 mg bid. Blood and 24-h urine samples were collected and body composition was assessed at baseline and after the intervention.

Effects of Lactobacillus casei and Bifidobacterium breve on urinary oxalate excretion in nephrolithiasis patients.

It had been suggested that lactic acid bacteria (LAB) may degrade oxalate in the intestinal lumen, reducing urinary oxalate excretion. We aimed to evaluate the effect of a LAB mixture containing Lactobacillus casei (LC) and Bifidobacterium breve (BB) (LC + BB) upon urinary oxalate reduction in stone-forming (SF) patients without hyperoxaluria under conditions of an oxalate-rich diet. After an oxalate restriction period (7 days washout), 14 SF patients consumed an oxalate-rich diet during 4 weeks (200 mg/day) and a lyophilized LC + BB preparation was given t.

Influence of muscle mass and physical activity on serum and urinary creatinine and serum cystatin C.

Background And Objectives: For addressing the influence of muscle mass on serum and urinary creatinine and serum cystatin C, body composition was assessed by skinfold thickness measurement and bioelectrical impedance analyses.

Design, Setting, Participants, & Measurements: A total of 170 healthy individuals (92 women, 78 men) were classified as sedentary or with mild or moderate/intense physical activity. Blood, 24-h urine samples, and 24-h food recall were obtained from all individuals.

Preservation of urine samples for metabolic evaluation of stone-forming patients.

Metabolic evaluation of stone-forming (SF) patients is based on the determination of calcium, oxalate, citrate, uric acid and other parameters in 24-h urine samples under a random diet. A reliable measurement of urinary oxalate requires the collection of urine in a receptacle containing acid preservative. However, urinary uric acid cannot be determined in the same sample under this condition.

Effect of vitamin C supplements on urinary oxalate and pH in calcium stone-forming patients.

Background: The contribution of ascorbate to urinary oxalate is controversial. The present study aimed to determine whether urinary oxalate and pH may be affected by vitamin C supplementation in calcium stone-forming patients.

Methods: Forty-seven adult calcium stone-forming patients received either 1 g (N=23) or 2 g (N=24) of vitamin C supplement for 3 days and 20 healthy subjects received 1 g.

Effects of an oxalate load on urinary oxalate excretion in calcium stone formers.

Objective: To investigate the oxalate intake and the effect of an oxalate load on urinary oxalate excretion in calcium stone-forming (CSF) patients.

Design: Prospective study.

Setting: University-affiliated outpatient Renal Lithiasis Unit.