Whey protein and albumin effects upon urinary risk factors for stone formation.
Protein supplements are consumed for an expected increase in muscle mass and improved exercise performance, but as their impact on lithogenic parameters are unknown, we aimed to evaluate the effects of Whey protein (WP) and Albumin upon the risk factors for nephrolithiasis. WP or Albumin supplements (one scoop/day) were administered for 3 days to 18 healthy volunteers, with 1-week washout period between them. Serum and 24-h urine samples were collected at baseline and after completing each intervention. All participants were asked to replicate their baseline diet during the subsequent urine collection. After WP or albumin, mean protein equivalent of nitrogen appearance (PNA) was significantly higher (p < 0.001), as the result of the consumption of each of the supplements, but mean urinary calcium, phosphorus, sodium, potassium, uric acid, citrate, oxalate, magnesium, creatinine, pH, and urinary saturation indices did not differ from baseline. However, individual increases higher than 50% in urinary calcium were observed in 39% of the individuals and variable decreases in urinary pH in 44 and 67% of them, respectively, after WP or Albumin. Increases higher than 50% in urinary sodium occurred in one-third of them after Albumin. A short-term consumption of WP or albumin by healthy subjects, under controlled diet, did not significantly change the mean lithogenic parameters. Nevertheless, the wide individual variation and relevant increases/decreases observed for urinary calcium, sodium, and pH suggest the need of a closer surveillance of these parameters and adequacy of diet in case of supplementation by stone formers.
Nephrology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu 740, Vila Clementino, CEP 04023-900, São Paulo, SP, Brazil.
Camila Mithie
CM
Hattori
Division of Urology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm, Sweden.
Hans-Göran
HG
Tiselius
Nephrology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu 740, Vila Clementino, CEP 04023-900, São Paulo, SP, Brazil. ita.heilberg@gmail.com.
Ita Pfeferman
IP
Heilberg
D000328:Adult; D000418:Albumins / Q000009:adverse effects*; D002118:Calcium / Q000652:urine; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007669:Kidney Calculi / Q000097:blood / Q000209:etiology* / Q000652:urine; D008297:Male; D012307:Risk Factors; D012964:Sodium / Q000652:urine; D000067816:Whey Proteins / Q000009:adverse effects*; D055815:Young Adult
D000418:Albumins; D000067816:Whey Proteins; D012964:Sodium; D002118:Calcium
Albumin; Hypercalciuria; Kidney stones; Nephrolithiasis; Whey protein