Presented by: Jenny Guo MD
Northwestern University

Introduction

Potassium citrate (KCit) is commonly prescribed to patients with recurrent nephrolithiasis, however medication compliance is poor due to gastrointestinal side-effects. Crystal light (CL) sugar-free lemonade is a low-calorie beverage alternative that has been shown to increase urinary citrate and pH levels. In this study, we aimed to compare the effects of potassium citrate and Crystal light on 24-hour urine collections

Materials

We performed a randomized crossover trial of 5 patients with isolated hypocitraturia on 24-hour urine collections. Patients completed one week trials of KCit (15mEq daily), CL (1L daily), and combination CL and KCit (500mL + 10mEq daily) followed by immediate 24-hour urine collections after each weekly treatment. Statistical analysis was conducted with p<0.05 representing significance.

Results

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The CL regimen led to the greatest increases in urinary volume (CL: 0.69 vs KCit: 0.16 vs Combo: 0.38, p=0.4) and urinary citrate (CL: 316 vs KCit: 120 vs Combo: 190, p=0.5) from baseline, however these differences did not reach statistical significance. The Combo regimen led to a mean increase in pH of 0.53 compared to 0.41 with CL and 0.07 with KCit (p=0.4). There were similar increases in supersaturation (SS) of calcium phosphate in all groups (CL: 0.28 vs KCit: 0.25 vs Combo: 0.27, p>0.9). The SS of calcium oxalate (CaOx) decreased by 0.91 in the CL group but showed slight increases in the KCit (0.78) and combo groups (0.07, p=0.7). Figure 1 depicts the stone risk factor plots comparing all groups.

Conclusion

CL was associated with the greatest increases in urine volume and urinary citrate and decreases in SS CaOx compared to KCit. However, these differences did not meet statistical significance. Further multi-institutional studies are needed to determine clinical significance.

Funding

none

Co-Authors

Nicholas Dean, MD
Northwestern University

Mark Assmus, MD
University of Calgary

Xinlei Mi, PhD
Northwestern University

Jessica Helon, BS
Northwestern University

Amy Krambeck, MD
Northwestern University

Matthew Lee, MD
The Ohio State University