Regular exercise during haemodialysis promotes an anti-inflammatory leukocyte profile

Background Cardiovascular disease (CVD) is the most common cause of mortality in haemodialysis (HD) patients and is highly predicted by markers of chronic inflammation. Regular exercise may have beneficial anti-inflammatory effects, but this is unclear in HD patients. This study assessed the effect of regular intradialytic exercise on soluble inflammatory factors and inflammatory leukocyte phenotypes. Methods Twenty-two HD patients from a centre where intradialytic cycling was offered thrice-weekly and 16 HD patients receiving usual care volunteered. Exercising patients aimed to cycle for 30 min at RPE of “somewhat hard”. Baseline characteristic were compared with 16 healthy age-matched individuals. Physical function, soluble inflammatory markers and leukocyte phenotypes were assessed again after 6 months of regular exercise. Results Patients were less active than their healthy counterparts and had significant elevations in measures of inflammation (IL-6, CRP, TNF-α, intermediate and non-classical monocytes; all P<0.001). Six months of regular intradialytic exercise improved physical function (sit-to- stand 60). After 6 months the proportion of intermediate monocytes in the exercising patients reduced compared to non-exercisers (7.58±1.68 to 6.38±1.81% vs. 6.86±1.45 to 7.88±1.66%; P<0.01). Numbers (but not proportion) of regulatory T cells decreased in the non-exercising patients only (P<0.05). Training had no significant effect on circulating IL-6, CRP or TNF-α concentrations. Conclusions These findings suggest regular intradialytic exercise is associated with an anti-inflammatory effect at a circulating cellular level but not in circulating cytokines. This may be protective against the increased risk of CVD and mortality that is associated with chronic inflammation and elevated numbers of intermediate monocytes.