Exercise Therapy in Individuals With Chronic Kidney Disease: A Systematic Review and Synthesis of the Research Evidence

Chronic kidney disease (CKD) is becoming a serious health problem throughout the world and is one of the most potent known risk factors for cardiovascular disease (CVD) which is considered the leading cause of morbidity and mortality in this cohort of patients. Additional independent risk factors for poor health outcomes among many include diabetes, physical inactivity and physical dysfunction. Physical inactivity partly contributes to the accelerated deterioration of physical function in people in all stages of CKD, to levels that significantly impact on clinically and patient important outcomes such as morbidity, employment, quality of life (QoL) and ultimately survival. Ongoing research aims to determine the effectiveness and impact of exercise rehabilitation on reducing/ managing the risk of CVD, alleviating physical function limitations, preventing disability and enhancing QoL. Current research also aims to elucidate the mechanisms via which exercise therapy may contribute to clinically relevant benefits. An evaluative overview of the available evidence from experimental interventions to modify PA levels, highlights the huge variability in exercise training and assessment protocols utilised and inconsistency in reporting procedures that hampers, systematic synthesis of the evidence. Nonetheless, the general conclusion that can be deciphered is that a mixed cardiovascular and resistance training programme that lasts at least 4-6 months, results in significant improvements in cardiorespiratory fitness. However, this level of improvement, does not consistently and meaningfully translates into enhanced CV risk profile or renal function, or QoL, even in the presence of improved physical function as a result of increased PA levels. The relatively short duration of interventions as well as the extremely small sample sizes, combined with the inherent large variability in individual responses and progression, may be partially responsible for the lack of a systematic and consistent effect. Moreover, the dose of exercise may have not been sufficient to produce larger effects in relatively short periods of time. Thus, although the research evidence base needs more work, that should incorporate more accurate and systematic approaches in the prescription and delivery of exercise dosage, the association between exercise and some enhanced outcomes in the CKD population is sufficiently strong to recognise the potential importance of this area of renal care and further invest in it.sch_phy31pub3290pu