Association between serum bicarbonate and pH with depression, cognition and sleep quality in hemodialysis patients

Ren Fail. 2015 Jul;37(6):957-60. doi: 10.3109/0886022X.2015.1038476. Epub 2015 Apr 20.


Metabolic acidosis is a common feature in chronic renal failure patients, worsening progressively as renal function declines. There are conflicting data in hemodialysis (HD) patients with regard to acidosis, alkalosis and mortality. In HD patients, cognitive impairment, depression, sleep disorders and impaired quality of life are very common. Besides, these conditions are related with increased morbidity and mortality. However, no previous study investigated the relationship between pH, venous bicarbonate and anion gap with depression, sleep problems and cognitive function in HD patients. In this study we investigated these relationships. In total, 65 HD patients were included. The demographic parameters and laboratory parameters including bicarbonate, pH and anion gap was measured for all patients. Depressive symptoms, sleep quality and cognitive function, were measured by Beck depression inventory, The Pittsburgh Sleep Quality Index and by Mini Mental State Examination, respectively. We found that, sleep quality but not cognitive function or depression was independently related with venous pH and bicarbonate. Anion gap has no independent relationship with sleep quality, cognitive function and depression. In conclusion, metabolic acidosis and bicarbonate levels were independently related with sleep quality in HD patients. However, there was no association between metabolic acidosis and bicarbonate levels with cognitive function and depression.

Keywords: Acidosis; bicarbonate; cognitive; depression; dialysis; sleep.

Publication types

  • Comparative Study
  • Observational Study

MeSH terms

  • Acidosis / diagnosis
  • Acidosis / epidemiology*
  • Age Distribution
  • Analysis of Variance
  • Bicarbonates / blood
  • Cognition Disorders / diagnosis
  • Cognition Disorders / epidemiology*
  • Cohort Studies
  • Comorbidity
  • Cross-Sectional Studies
  • Depressive Disorder / diagnosis
  • Depressive Disorder / epidemiology*
  • Female
  • Follow-Up Studies
  • Humans
  • Hydrogen-Ion Concentration
  • Incidence
  • Kidney Failure, Chronic / blood
  • Kidney Failure, Chronic / epidemiology
  • Kidney Failure, Chronic / therapy*
  • Linear Models
  • Male
  • Multivariate Analysis
  • Neuropsychological Tests
  • Polysomnography / methods
  • Renal Dialysis / adverse effects
  • Renal Dialysis / psychology*
  • Severity of Illness Index
  • Sex Distribution
  • Sleep Wake Disorders / diagnosis
  • Sleep Wake Disorders / epidemiology*
  • Statistics, Nonparametric
  • Survival Rate


  • Bicarbonates