The legacy effect of a home walking exercise program in kidney failure patients on dialysis.

BACKGROUND The EXCITE trial (JASN 28: 1259-1268, 2017) in dialysis patients showed that a 6-month home walking exercise program improves physical function and two dimensions of the KDQOLSF-SF™ questionnaire. Whether improvements in physical function achieved by exercise interventions are maintained in the long term has never been tested in the dialysis population. METHODS In this post-trial study embedded in the EXCITE trial we tested the response to the 6MWT and the 5STS tests and the KDQOLSF-SF™ from the 6th month (end of the trial) to the 36th month. RESULTS Among the 227 patients of the EXCITE trial cohort, 162 underwent at least three out four testing visits (baseline, 6, 18 and/or 36 month) contemplated by the study protocol and 89 all four testing visits. In the primary analysis by the linear mixed model the gain in walking distance achieved at 6th month in the exercise group (between-arms difference: +36 meters, 95% CI: 22-51, P < 0.001) was maintained at the 18th month (between-arms difference: +37 meters, 95% CI: 19-57, P < 0.001) to reduce to 23 meters (95% CI: -4 to 49 meters, P = 0.10) at 36th month. Overall, the post trial difference in walking distance trajectories between the two study arms was highly significant (P = 0.004). Furthermore, the walking distance changes at the 6th (r = 0.34, P = 0.018) and 18th month (r = 0.30, P = 0.043) were directly related with number of structured exercise sessions completed during the trial (i.e. the first 6 months). No such an effect was registered in the response to the 5STS or in quality of life as measured by the KDQOLSF-SF™. CONCLUSIONS In dialysis patients the benefits of a 6-months structured walking program outlast the duration of the intervention and postpone the loss of walking performance which naturally occurs in this population but does not affect QoL and the response to the STS test.