Kidney Function and Physical Performance Decline: The Brain in Kidney Disease (BRINK) Cohort Study

Area of Science:

• Nephrology
• Geriatrics
• Physical Medicine

Background:

• Patients with kidney failure exhibit diminished physical performance, but the progression of this decline throughout kidney disease, including the transition to dialysis, remains unclear.
• Understanding the trajectory of physical function in chronic kidney disease (CKD) is crucial for patient management and intervention strategies.

Purpose of the Study:

• To investigate the association between estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (UACR) with changes in physical performance over time.
• To examine the trajectory of physical function, including the Short Physical Performance Battery (SPPB) and gait speed, in adults with CKD, particularly around the initiation of dialysis.

Main Methods:

• An observational cohort study of 562 community-dwelling adults aged ≥45 years from the Brain in Kidney Disease (BRINK) cohort.
• Linear mixed-effects regression models were used to analyze changes in SPPB and gait speed in relation to eGFR and UACR over a median follow-up of 63 months.
• Covariate-adjusted models were employed to account for potential confounding factors.

Main Results:

• A graded association was observed between lower eGFR and greater decline in SPPB scores, with steeper declines in individuals with more advanced CKD stages.
• Higher UACR was significantly associated with a greater decline in both SPPB scores and gait speed, independent of eGFR.
• While SPPB score decline did not accelerate after dialysis initiation in adjusted models, gait speed continued to decline post-dialysis.

Conclusions:

• Chronic kidney disease stage and albuminuria are associated with a progressive decline in physical performance.
• Physical performance, as measured by SPPB, appears to stabilize after dialysis initiation, whereas gait speed continues to decline, suggesting distinct impacts of kidney disease progression and dialysis on different physical function measures.