Discussion
cognitive impairment, attention impairment, HD, dementia, alertness, cognitive and mobility impairments, intradialytic, cognitive decline
This study investigated the effects of 12 weeks of combined physical and cognitive training on attention domains and SGS. Results from RM ANOVA showed a significant between-group interaction over time in alertness and SGS in favor to the EXP group. Within-group analysis in attention domains revealed a significant pre–post difference solely in the CON group in alertness test score, indicating a noticeable decline in this specific cognitive domain over the course of the study. Furthermore, the intervention resulted in a significant improvement in SGS compared with standard care.While significant within-group improvements in attention domains were not observed, our intervention was found to be associated with the preservation of these domains. In contrast, the CON group exhibited a slight decline in selective attention and a significant decline in alertness. These results indicate that our intervention had a beneficial effect in maintaining attention abilities, providing support for its potential effectiveness in preventing cognitive decline in these domains. Our findings are consistent with gerontology studies, in which cognitive training and/or physical exercise training improved or preserved some, although not all, cognitive domains [In a recent study conducted by Guo et al. (2022), attention was identified as the cognitive domain exhibiting the highest proportion of impairment among HD patients. The current study supports this finding by showing a significant reduction in alertness in the control group over a short period of time, indicating a rapid decline in this subdomain of attention. Importantly, Guo et al. (2022) also found a significant correlation between attention impairment and higher mortality rates in this population [This is the first study examining the effects of a non-pharmacological intervention on the domains of attention in HD patients. Only one study investigated the effects of either intradialytic cycling or intradialytic tablet-based cognitive training on cognitive performance in HD patients [A plethora of literature now exists linking cognitive processes, particularly executive functions and attention, with gait [Tests such as the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) are primarily used for screening mild cognitive impairment and dementia and may not be sufficiently sensitive to detect intervention effects [A limitation is that the results would benefit from replication in larger samples to improve their generalizability. Furthermore, it should be noted that the mean age of our sample was relatively low. Consequently, it is possible that older patients may exhibit lower tolerability to physical exercise interventions. Future research should include three separate groups, one participating solely in intradialytic cycling, cognitive training and the third group with both interventions. Due to the nature of the intervention, blinding of investigators and subjects was not possible. However, outcome assessors were blinded to group allocation. Consideration of these limitations helps to contextualize the results and highlight opportunities for future research to address these concerns and expand our understanding of cognitive function and mobility in this population.Overall, incorporating both physical exercise and cognitive training into the care of HD patients may offer a comprehensive approach to improving their overall functioning. Further investigation is required to elucidate the underlying mechanisms and identify specific targets for preventive and therapeutic interventions. Additionally, there is a pressing need to develop tailored clinical care practices to help HD patients who experience cognitive and mobility impairments. Future research endeavors should also prioritize identifying risk factors associated with functional decline. By addressing these research gaps, we can advance our understanding and improve the management of cognitive and mobility impairments in this population.