Low urine pH Is a predictor of chronic kidney disease

Kidney Blood Press Res. 2012;35(2):77-81. doi: 10.1159/000330487. Epub 2011 Sep 7.

Abstract

Background/aims: A variety of risk factors for chronic kidney disease (CKD), including the metabolic syndrome, were recently reported. It has been suggested that a low urine pH is another characteristic of the metabolic syndrome. However, the relationship between urine pH and CKD remains to be elucidated.

Methods: A cohort study was performed on 1,811 subjects who underwent a health check-up, and we examined whether low urine pH could be a predictor of CKD. The following risk factors for CKD were evaluated: age, gender, history of alcohol intake and smoking, BMI, systolic blood pressure, fasting plasma glucose, total cholesterol, uric acid, total leukocyte count, CKD stage, fasting urine pH, and protein at baseline.

Results: We followed 1,811 subjects for a median period of 7.7 years. Three hundred and thirty-nine subjects developed stage 3 CKD defined as progression to estimated glomerular filtration rate < 60 ml/min/1.73 m(2). Multiple Cox regression analysis revealed that the adjusted HR (95% CI) for stage 3 CKD was 1.32 (1.06-1.65; p = 0.0129) in subjects with fasting urine pH 5.0-5.5 compared to subjects with pH 6.5-7.0.

Conclusion: Our study suggests that low urine pH is an independent predictor of stage 3 CKD.

MeSH terms

  • Acids / urine*
  • Adult
  • Cohort Studies
  • Fasting / urine
  • Female
  • Glomerular Filtration Rate / physiology
  • Humans
  • Hydrogen-Ion Concentration
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Proportional Hazards Models
  • Renal Insufficiency, Chronic / diagnosis
  • Renal Insufficiency, Chronic / epidemiology*
  • Renal Insufficiency, Chronic / urine*
  • Risk Factors
  • Severity of Illness Index*

Substances

  • Acids