The relationship between serum bicarbonate, pH level and sleep quality in hemodialysis patients: A cross-sectional study from Turkey

To investigate the relationship of blood pH and bicarbonate levels with sleep disorders in patients with end-stage renal disease.The cross-sectional study was conducted at Kocaeli Derince Health Practice and Research Center, Kocaeli, Turkey, in July 2015, and comprised stable haemodialysis patients aged over 18 years who had undergone at least 3 months of treatment. The Pittsburgh sleep quality index was used to assess sleep quality, and the Epworth sleepiness scale was used to assess sleepiness. Blood urea nitrogen levels were measured to determine dialysis success. SPSS 17 was used for data analysis.Of the 62 patients, 22(35.4%) were good sleepers, while 40(65.6%) were bad sleepers, and 11(17.7%) had excessive daytime sleepiness. There was no significant difference between poor and good sleepers with respect to venous pH (p=0.197) and bicarbonate (p=0.305) levels. Also, the two levels did not differ significantly between patients with routine or excessive daytime sleepiness (p>0.05). Patients with excessive daytime sleepiness had significantly lower calcium (p=0.046) and higher creatinine (p-0.014) levels and were older (p=0.01). Age was the only independent predictor of both the index and the scale scores (p<0.05 each).Sleep disorders and sleepiness were found to be high in haemodialysis patients and there was a strong correlation between sleep disturbance and age. There was no correlation of either state with patients' bicarbonate or venous pH values.