Association of accelerometer-measured physical activity with adverse cardiovascular outcomes in individuals with or without chronic kidney diseases: the UK biobank study.

Background: Physical activity is important for health and longevity, but little is known on patients living with chronic kidney disease (CKD). In fact, most studies in patients with CKD have relied on self-reported data, highlighting an unmet need for studies using objective measurements. We investigated the association between device-measured physical activity and adverse outcomes by CKD status.

Methods: This study included 65,088 participants without CKD and 1170 with CKD, from the UK Biobank, who completed a one-week accelerometer assessment. CKD was defined as either baseline estimated glomerualr filtration rate (eGFR) < 60 mL/min/1.73 m² or two consecutive eGFR measurements < 60 mL/min/1.73 m² from primary care data recorded prior to the accelerometer study. The main predictor was device-measured physical activity, categorized into quartiles. The primary outcome was all-cause mortality; secondary outcomes included three-point major adverse cardiovascular events and non-cardiovascular death. We used cause-specific competing risk models adjusting for multiple covariates.

Results: Over a median follow-up period of 8.04 years, all-cause mortality occurred in 2028 (3.06%) participants, with an incidence of 3.84/1000 person-years. Compared with the 1st quartile, the adjusted hazard ratios (95% confidence intervals) for all-cause mortality for the 2nd, 3rd, and 4th quartiles were 0.72 (0.64-0.80), 0.65 (0.57-0.72), and 0.57 (0.49-0.66) in non-CKD, and 0.56 (0.33-0.96), 0.42 (0.23-0.79), and 0.33 (0.16-0.68) in CKD participants. This pattern was consistent for non-cardiovascular deaths. However, device-measured physical activity was not significantly associated with three-point major adverse cardiovascular events in CKD, while a significant association was observed in the non-CKD group.

Conclusion: Device-measured physical activity showed differential associations with outcomes by CKD status. The null association between physical activity and three-point major adverse cardiovascular events in CKD suggests a complex cardiovascular pathophysiology in this population.