Effect of low-potential renal acid load diet intervention on urinary lithogenic parameters in recurrent calcium urolithiasis patients (A Preliminary Randomized Controlled Trial)
摘要
To compare the efficacy of low PRAL dietary intervention against potassium citrate (PCi) extended-release medication in modifying key urinary lithogenic parameters for oxalate calcium calculi formation over a four-week duration. We conducted a three-arm, parallel-group study with 46 participants randomized into a Diet group (n = 14), a Medicine group (n = 16), and a Control group (n = 16). Twenty-four-hour urine samples were collected at baseline, two weeks, and four weeks. Nine primary urinary outcomes were analyzed: Citrate (Cit), Potassium (UK), pH, Oxalate (OX), Calcium (UCa), Sodium (UNa), Chloride (UCl), Urine Volume, and estimated Potential Renal Acid Load (PRAL). Longitudinal changes were assessed using Linear Mixed-Effects Models (LMMs). Baseline characteristics were well-balanced across the three groups (p > 0.05 for most of indicators) except citrate. The LMM analysis revealed that the Medicine group showed statistically significant improvements compared to the Control group in urine potassium and PRAL at two weeks and continued to four weeks (p < 0.001). Urine laboratory tests changes in diet intervention were not significant over time, however, the Diet group showed slight modification of the urine protective factors, such as urine potassium and pH, to alkalinization. Diet intervention no significant changes were observed in urine stone formation potential lithogenic factors including calcium, sodium, chloride, or oxalate. The low–potential renal acid load (PRAL) diet, characterized by higher consumption of vegetables, fruits, and less animal-based proteins, produced gradual but modest improvements in urinary parameters linked to calcium oxalate stone prevention. While prolonged dietary compliance was associated with correcting urine acidification, the dietary intervention exerted only a limited impact on other major lithogenic factors.