Short-Term Effects of Intradialytic Hypoxemia on Plasma Markers of Hypoxia

Background: Transient intradialytic hypoxemia (IDH) often occurs during dialysis treatment. Intradialytic hypoxemia has been linked to several clinically relevant complications. SIRT1 modulates cells response to hypoxia. Some experimental studies suggest that sirtuins are involved in the regulation of various physiological processes in the kidney, including the response to oxidative stress and production of erythropoietin. The aim of the study was to analyze the effect of IDH on secretion of hypoxia-inducible factor and sirtuins Methods: The study group included 49 chronic hemodialysis patients, mean age 59 +/- 15 years, dialysis vintage 3.3 +/- 4.1 years, from a single tertiary renal center. Continuous recording of pulse oximetry was carried out during a whole hemodialysis session. Blood for assessment of SIRT, HIF 1, HIF 2 levels was taken four times. Intradialytic hypoxemia was defined as a decrease of blood oxygen saturation below 90%. Results: IDH occurred in 22 patients (44.9%). A significant positive correlation was found between interdialytic body mass gain and mean oxygen saturation (r= 0,37; p<0,008). The only molecule that significantly predicted the decreases of blood oxygen saturation in a multivariate model was pre-dialysis serum sirtuin-1 A statistically significant positive correlation was observed between the coefficient of variation of oxygen saturation and the plasma concentration of SIRT. Variability of oxygen saturation and intradialytic hypoxemia are not related to the patient's age, dialysis vintage and duration of single hemodialysis treatment. Conclusion: The assessment of predialysis sirtuin-1 level may be used as a predictor of clinically significant decreases of blood oxygen saturation during hemodialysis session.