Abstract: TH-PO1122

Associations between Urine pH and Body Mass Index, Serum Uric Acid, Urine Gravity, and Kidney Function

Session Information

Category: Fluid, Electrolytes, and Acid-Base

  • 704 Fluid, Electrolyte, Acid-Base Disorders

Authors

  • Kuwabara, Masanari, University of Colorado Denver, Aurora, Colorado, United States
  • Roncal-jimenez, Carlos Alberto, University of Colorado, Aurora, Colorado, United States
  • Andres-hernando, Ana, University of Colorado Denver, Aurora, Colorado, United States
  • Sato, Yuka, University of Colorado, Aurora, Colorado, United States
  • Jensen, Thomas, University of Colorado, Aurora, Colorado, United States
  • Garcia, Gabriela E., University of Colorado Denver, Aurora, Colorado, United States
  • Lanaspa, Miguel A., University of Colorado Denver, Aurora, Colorado, United States
  • Johnson, Richard J., University of Colorado Denver, Aurora, Colorado, United States
Background

Obesity and metabolic syndrome are increasing in decades. Obesity usually decreases urine pH, and low urine pH is a good marked for metabolic diseases. Serum uric acid is also a good marker for metabolic syndrome. Uric acid is crystallized in low pH, which induces renal dysfunctions. This study is to clarify the association between urine pH and body mass index, serum uric acid, and kidney function.

Methods

This study is a large-scale cross-sectional study. We retrospectively analyzed the database from 90,143 Japanese people (men, 49.1%; age, 46.3 ± 12.0 years) undergoing annual medical examination at the Center for Preventive Medicine, St. Luke’s International Hospital, Tokyo between January 2004 and June 2010. The subjects with any current medication were excluded. We tested the association between body mass index and urine pH. Furthermore, we analyzed the association between urine pH and body mass index (BMI), serum uric acid, urine gravity, and estimated glomerulus filtration rate (eGFR) levels in a healthy population.

Results

Of 90,143 subjects, 21,574 subjects with current medication and 595 subjects without urine data were excluded, and finally 67,974 subjects were enrolled in the study. Urine pH had significantly inverse correlation with BMI (r=-0.1, p<0.001), serum uric acid (r=-0.12, p<0.001), and urine gravity (r=-0.28, p<0.001). Moreover, low urine pH (less than 6.0, eGFR=80.9±14.4) and high urine pH (more than 7, eGFR=81.7±15.9) showed significantly lower eGFR compared to normal urine pH (from 6 to 7, eGFR=84.5±15.3) (p<0.001). Figure showed the mean level of BMI, serum uric acid, urine gravity and eGFR in each urine pH.

Conclusion

Low urine pH (less than 6) becomes a good marker for high BMI, high serum uric acid, and dehydration status (high urine gravity), which is associated with low eGFR.