Photo Credit: Adobe

The following is a summary of “Acute Effect of Moderate-Intensity Interval Intradialytic Exercise on Cerebral Oxygenation in Hemodialysis Patients,” published in the March 2025 issue of Journal of the American Society of Nephrology by Kojima et al. 

Cognitive dysfunction in patients with hemodialysis (HD) links to reduced regional cerebral oxygenation (rSO₂). The acute effect of intradialytic exercise on circulation remains unclear. 

Researchers conducted a retrospective study to assess the acute effect of intradialytic exercise on rSO₂ during HD.  

They conducted a single-center, open-label, randomized crossover trial with 20 patients with HD. Patients received usual care or intradialytic exercise in random order, including 35 min of anaerobic threshold-intensity intervals. Cerebral oxygenation (rSO₂, oxygenated, deoxygenated, and total hemoglobin) in the prefrontal cortex was measured using near-infrared spectroscopy. Cardiovascular responses, including heart rate, cardiac index, mean arterial pressure, and blood gas, were assessed. Conditions were compared using 2-way repeated-measures ANOVA. 

The results showed that 16 patients were analyzed, with 4 excluded due to artifacts. rSO₂ (P<0.001), oxygenated hemoglobin (P<0.001), and total hemoglobin (P=0.004) significantly increased at the end of exercise (rSO₂ 1.3%, 95%CI [0.5, 2.1]; oxygenated hemoglobin 0.01 mM, 95%CI [0.00, 0.02]; total hemoglobin 0.01 mM, 95%CI [0.00, 0.03]) and 15 min after (rSO₂ 1.1%, 95%CI [0.2, 2.0]; oxygenated hemoglobin 0.01 mM, 95%CI [0.00, 0.03]; total hemoglobin 0.02 mM, 95%CI [0.00, 0.03]) in the exercise condition. rSO₂ at the end of HD significantly decreased in the control (-1.5%, 95%CI [-2.7, -0.3]) but not in the exercise condition (-1.2%, 95%CI [-2.8, 0.5]). 

Investigators found that intradialytic exercise significantly increased rSO₂ during and after exercise, restoring it to pre-dialysis levels. 

Source: journals.lww.com/jasn/abstract/9900/acute_effect_of_moderate_intensity_interval.584.aspx