Longitudinal analysis of physical activity, fluid intake, and graft function among kidney transplant recipients

Abstract

Self-care is recommended to kidney transplant recipients as a vital component to maintain long-term graft function. However, little is known about the effects of physical activity, fluid intake, and smoking history on graft function. This longitudinal study examined the relationship between self-care practices on graft function among 88 new kidney transplant recipients in Chicago, IL and Albany, NY between 2005 and 2008. Participants were interviewed, completed surveys, and medical charts were abstracted. Physical activity, fluid intake, and smoking history at baseline were compared with changes in estimated glomerular filtration rate (eGFR) (every 6 months up to 1 year) using bivariate and multivariate regression analysis, while controlling for sociodemographic and clinical transplant variables. Multivariate analyses revealed that greater physical activity was significantly (P < 0.05) associated with improvement in GFR at 6 months; while greater physical activity, absence of smoking history, and nonwhite ethnicity were significant (P < 0.05) predictors of improvement in GFR at 12 months. These results suggest that increasing physical activity levels in kidney recipients may be an effective behavioral measure to help ensure graft functioning. Our findings suggest the need for a randomized controlled trial of exercise, fluid intake, and smoking history on GFR beyond 12 months.

Figure 1

Covariance-adjusted GFR levels at 6 and 12 months, by level of physical activity reported at baseline. Six-month GFR is adjusted for baseline GFR, adherence to recommended fluid intake, gender, and race/ethnicity; 12-month GFR is adjusted for baseline GFR, adherence to recommended fluid intake, gender, race/ethnicity, smoking, and number of transplants. Baseline GFR is calculated from the plateau; average time to plateau ranged from 2 to 4 weeks post-transplant.