Background. Chronic inflammation in haemodialysis (HD) patients indicates a poor prognosis. However, therapeutic approaches are limited. Hydrogen gas (H2) ameliorates oxidative and inflammatory injuries to organs in animal models. We developed an HD system using a dialysis solution with high levels of dissolved H2 and examined the clinical effects.
Methods. Dialysis solution with H2 (average of 48 ppb) was produced by mixing dialysate concentrates and reverse osmosis water containing dissolved H2 generated by a water electrolysis technique. Subjects comprised 21 stable patients on standard HD who were switched to the test HD for 6 months at three sessions a week.
Results. During the study period, no adverse clinical signs or symptoms were observed. A significant decrease in systolic blood pressure (SBP) before and after dialysis was observed during the study, and a significant number of patients achieved SBP <140 mmHg after HD (baseline, 21%; 6 months, 62%; P < 0.05). Changes in dialysis parameters were minimal, while significant decreases in levels of plasma monocyte chemoattractant protein 1 (P < 0.01) and myeloperoxidase (P < 0.05) were identified.
Conclusions. Adding H2 to haemodialysis solutions ameliorated inflammatory reactions and improved BP control. This system could offer a novel therapeutic option for control of uremia.
Accumulating evidence suggests that enhanced oxidative stress and inflammation in patients on haemodialysis (HD) play crucial roles in the increased risk of cardiovascular events and infectious diseases, which result in a poor prognosis for the patient [1–3]. Randomized control studies using antioxidants in HD patients suppressed cardiovascular events using high-dose vitamin E  and acetylcysteine , but conflicting results were reported for non-dialysis chronic kidney disease . While inflammation significantly affects HD patients, clinically available agents to directly suppress inflammatory markers are lacking for HD patients . Dihydrogen (H2) is an inert gas with no known side effects. Recent studies have shown that administration of H2 dissolved in water can suppress oxidative or inflammatory injury to organs in animal models, such as ischaemic reperfusion in the brain  and liver , stress-induced oxidative injury in the hippocampus , and inflammatory reactions in the colon induced by dextran sodium sulphate . Furthermore, H2 inhalation mitigates small intestine inflammation due to transplantation . H2 reacts with hydroxyl radicals [8,13], and thus could prevent injury caused by radical oxygen species. Applying H2 to HD solutions, for anti-oxidative and anti-inflammatory effects, represents a unique clinical approach.