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Abstract: SA-PO689

Quantitative Assessment of Overall Acid-Base Balance in Humans

Session Information

Category: Fluid, Electrolytes, and Acid-Base Disorders

  • 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical

Authors

  • Badawy, Yasin R., University of Chicago Division of the Biological Sciences, Chicago, Illinois, United States
  • Rawal, Priya M., University of Chicago Division of the Biological Sciences, Chicago, Illinois, United States
  • Coe, Fredric L., University of Chicago Division of the Biological Sciences, Chicago, Illinois, United States
  • Worcester, Elaine M., University of Chicago Division of the Biological Sciences, Chicago, Illinois, United States
  • Prochaska, Megan, University of Chicago Division of the Biological Sciences, Chicago, Illinois, United States
Background

Kidney stones are common and understanding mechanisms contributing to stone formation is important in developing effective prevention and treatment strategies. This study aimed to investigate the impact of various predictors on urine pH and acid-base homeostasis, which play a significant role in kidney stone formation.

Methods

Kidney stone patients and non-kidney stone patients provided 24-hour urine collections while at home and eating a free choice diet. A pH titration analysis was performed and acid-base parameters were measured in the urine to assess acid-base balance. Basic statistics and linear models were developed to characterize change in urine acid-base chemistry as a function of demographic and urine factors.

Results

There were 246 participants with mean age 54 years, 133 female, and 190 kidney stone patients. In multivariate analysis, higher age was associated with lower urine pH (-0.005 per year, p<0.001) but there was no association by sex. In separate multivariate models, male sex was associated with lower acid excretion (-0.6 meq/mM creatinine, p<0.001) and lower urine anions (-0.5meq/mM creatinine, p<0.01) compared with female. In separate multivariate models, higher age was associated with higher urine anion (0.02 meq/mM creatinine per year, p<0.001) and higher titratable acidity (0.01 meq/mM creatinine per year p<0.001).

Conclusion

This study provides valuable insights into the relationships between demographic factors and urine acid-base chemistry. The association between age and sex with urine pH, urine anions, acid excretion, and titratable acidity underscores the importance of age and sex as factors in acid-base balance. This may also suggest different mechanisms for kidney stone formation in older adults and between men and women and is consistent with known data that stone types may change with aging and there are differences between men and women.

Funding

  • NIDDK Support