Association of Physical Activity Trajectories with Longitudinal Changes in Renal Function among Older Chinese Adults: A Prospective Cohort Study

Abstract

Abstract Background To investigate association between physical activity trajectories and longitudinal changes in renal function. We performed this study in Chinese adults with 60 years or older using data from China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 2015. Methods Latent class trajectory modeling (LCTM) was applied to identify heterogeneous trajectories of physical activity scores (PAS) from 2011 to 2015. Generalize linear models were adopted to investigate the relationship between trajectories of PAS and the annualised rate of change in estimated glomerular filtration rate based on serum creatinine and cystatin C (slope of eGFRcr-cys). Serial mediation analysis was conducted to reveal significant mediating pathways from trajectories of PAS to the slope of eGFRcr-cys. Results A total number of 407 participants aged 60 years or older were divided into 5 classes based on different PAS trajectories. After adjustment for potential confounders (age, drinking in last year, diabetes mellitus, heart disease, kidney disease, baseline eGFRcr-cys and baseline uric acid), compared with class 1, class 2 was associated with an increase of 0.65 [95% confidence interval (CI), -0.39-1.68] in the slope of eGFRcr-cys; class 3 was associated with an increase of 1.24 (95%CI, 0.37–2.10) in the slope of eGFRcr-cys; class 4 was associated with an increase of 1.64 (95%CI, 0.65–2.63) in the slope of eGFRcr-cys; class 5 was associated with an increase of 2.37 (95%CI, 1.37–3.36) in the slope of eGFRcr-cys. Notably, a significant mediating pathway from trajectories of PAS to the slope of eGFRcr-cys through serial mediation of triglyceride-glucose (TyG) index and baseline eGFRcr-cys was found. Conclusions A slow-rise trajectory starting from a more than moderate level of PAS.(class 5) is preferable in terms of slowing renal function decline among older Chinese adults aged 60 years or more. For older people, this PA trajectory is recommended owing to its potential beneficial impact on renal function. A significant mediating pathway from trajectories of PAS to the slope of eGFRcr-cys is through serial mediation of TyG index and baseline eGFRcr-cys, which partially explains how PA trajectories are associated with longitudinal changes in renal function.